A patterned fluorine-containing zinc cobaltate doped fluorinated graphene, a preparation method and applications thereof

Abstract

This invention relates to the field of novel graphene technology, and more particularly to a patterned zinc cobalt fluoride-doped fluorinated graphene, its preparation method, and its application. The patterned zinc cobalt fluoride-doped fluorinated graphene is prepared by this method. The method includes obtaining a zinc cobalt fluoride-doped fluorinated polyamic acid composite resin; coating the composite resin onto a carrier to form a coating layer; subjecting the coating layer to a stepped heating heat treatment to obtain a zinc cobalt fluoride-doped fluorinated polyimide film; cooling the film, then immersing it in water, and peeling it off from the carrier; and laser-processing the peeled film to form patterned zinc cobalt fluoride-doped fluorinated graphene. The application is that this patterned zinc cobalt fluoride-doped fluorinated graphene is used as an electrode material in the fabrication of micro supercapacitors. This invention can prepare patterned zinc cobalt fluoride-doped fluorinated graphene electrode materials with good capacitance characteristics and a large area-to-capacitance ratio.

Description

Technical Field

[0001] This invention relates to the field of novel graphene technology, and in particular to a patterned zinc fluoride-doped fluorinated graphene, its preparation method, and its application. Background Technology

[0002] Fluorinated graphene is a novel graphene derivative that is partially fluorinated. It not only possesses the unique two-dimensional structure of graphene, but also exhibits distinct physicochemical properties due to the introduction of fluorine atoms. These properties include lower surface energy, excellent hydrophobicity, and a tunable band gap. These characteristics give it broad application potential in numerous technological fields such as micro / nanoelectronic devices, wearable electronic devices, and energy storage and conversion devices.

[0003] Commonly used methods for preparing fluorinated graphene in existing technologies include direct fluorination and mechanical exfoliation. The direct fluorination method involves reacting graphite or graphene with fluorine gas in a sealed environment at 150–300°C, controlling the time and amount of fluorine to introduce C–F bonds onto the carbon surface, resulting in fluorinated graphene. The degree of fluorination is confirmed by characterization using X-ray photoelectron spectroscopy. While the direct fluorination method can produce fluorinated graphene, it is complex, costly, and involves the hazardous reagent fluorine gas. The mechanical exfoliation method involves repeatedly peeling away highly oriented graphite with adhesive tape, transferring few-layer or single-layer graphene onto a substrate such as a silicon wafer. Single-layer graphene is then characterized and screened using optical, Raman, and / or atomic force microscopy to obtain high-quality two-dimensional carbon materials. While the mechanical exfoliation method can also produce fluorinated graphene, it is inefficient and difficult to scale up. Furthermore, both methods produce powdered products, requiring additional and complex processes to transfer and fix these powdered products onto the substrate during device fabrication. This transfer step severely limits the direct manufacturing and development of high-performance patterned devices.

[0004] Furthermore, in 2014, researchers discovered that polyimide can form graphene under laser irradiation, known as laser-induced graphene. This graphene not only possesses a three-dimensional porous structure but also boasts a simple fabrication process and patternability. Additionally, it exhibits good flexibility, making it widely applicable in flexible functional devices such as supercapacitors and sensors. However, undoped laser-induced graphene exhibits poor capacitance characteristics and a small areal capacitance, severely limiting its application prospects.

[0005] Therefore, it is necessary to provide a patterned zinc cobalt fluoride-doped fluorinated graphene, its preparation method, and its application to solve the problems of poor capacitance characteristics and small area-to-capacitance exhibited by undoped laser-induced graphene in the prior art. Summary of the Invention

[0006] The purpose of this invention is to provide a patterned zinc cobalt fluoride-doped fluorinated graphene, its preparation method, and its application. The specific technical solution is as follows:

[0007] In a first aspect, the present invention provides a method for preparing patterned zinc fluorinated cobalt oxide-doped fluorinated graphene, comprising:

[0008] Step S1: Add zinc fluorocobaltate and diamine monomer to a polar organic solvent and stir until homogeneous; then, add dianhydride monomer in batches while stirring to form a reaction system. Through polycondensation, continue the reaction until the viscosity reaches 50,000~250,000 centipoise to obtain a zinc fluorocobaltate-doped fluorinated polyamic acid composite resin; the solid content of the composite resin is adjusted to 12%~25% using the polar organic solvent.

[0009] Wherein, the dianhydride monomer and / or the diamine monomer are fluorine-containing monomers; the molar ratio of the dianhydride monomer to the diamine monomer is 0.95:1 to 1.1:1; in the reaction system, the mass percentage of the zinc fluorocobaltate is 1% to 12%;

[0010] Step S2: The composite resin is coated onto the carrier to form a coating; the coating is subjected to a stepped heating heat treatment to obtain a fluorinated polyimide film doped with zinc fluorine cobalt oxide; the film is cooled, then soaked in water, and then peeled off from the carrier.

[0011] Step S3: The peeled film is laser-processed to form patterned zinc cobalt fluoride-doped fluorinated graphene.

[0012] Optionally, the preparation steps of the zinc fluorocobaltate include:

[0013] Zinc source, cobalt source, fluorine source, precipitant and deionized water are mixed in the required molar ratio of 1:2:2~6:3~12:30~40 and then subjected to hydrothermal treatment to obtain zinc fluoride cobaltate precursor.

[0014] After cooling, the zinc cobalt fluoride precursor is rinsed at least five times each with deionized water and anhydrous ethanol.

[0015] The rinsed zinc fluorinated cobaltate precursor was subjected to drying, annealing and chemical reduction treatment in sequence to obtain zinc fluorinated cobaltate with oxygen vacancies.

[0016] Wherein, the zinc source includes zinc nitrate; the cobalt source includes cobalt nitrate; the fluorine source includes ammonium fluoride; the precipitant includes urea; and the hydrothermal treatment uses a hydrothermal temperature of 120~180℃ and a hydrothermal time of 3~24h.

[0017] The drying process uses a drying temperature of 60~90℃ and a drying time of 8~24h.

[0018] The annealing process is carried out under air conditions, with an annealing temperature of 400~800℃ and an annealing time of 3~8h.

[0019] The reducing agent used in the chemical reduction treatment is NaBH4 solution, and the reduction time is 3-5 hours; the molar concentration of the NaBH4 solution is 0.2-1.0 mol / L; and the mass of the zinc fluorocobaltate precursor in each liter of the NaBH4 solution is 25-75 g.

[0020] Optionally, when the dianhydride monomer is a fluorinated dianhydride monomer, it includes 4,4'-(hexafluoroisopropyl)bisphthalic anhydride;

[0021] Alternatively, when the dianhydride monomer is a fluorine-free rigid aromatic dianhydride monomer, it includes biphenyltetracarboxylic dianhydride or pyromellitic dianhydride.

[0022] Optionally, the diamine monomer is a fluorinated diamine monomer; or, the diamine monomer is a non-fluorinated rigid aromatic diamine monomer; or, the diamine monomer includes a fluorinated diamine monomer and a non-fluorinated rigid aromatic diamine monomer.

[0023] The fluorinated diamine monomers include 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl or 4,4'-bis(2-trifluoromethyl-4-aminophenoxy)diphenyl ether;

[0024] The fluorine-free rigid aromatic diamine monomers include at least one of 4,4'-diaminodiphenyl ether and p-phenylenediamine.

[0025] Optionally, the polar organic solvent includes any one of N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone.

[0026] Optionally, the thickness of the coating is 25~150μm;

[0027] The stepped heating heat treatment includes a first heating stage, a second heating stage, and a third heating stage with the heating temperature increasing sequentially; wherein, in the first heating stage, the heating temperature is 60~100℃ and the heating time is 10~60min; in the second heating stage, the heating temperature is 150~250℃ and the heating time is 10~120min; and in the third heating stage, the heating temperature is 280~350℃ and the heating time is 10~60min.

[0028] The heating rate used from the first heating stage to the second heating stage is 5~15℃ / min;

[0029] The heating rate used from the second heating stage to the third heating stage is 5~15℃ / min.

[0030] Optionally, the laser processing includes a first laser engraving process and a second laser engraving process; the power used in the first laser engraving process and the second laser engraving process is 3~10w, and the engraving speed is 80~300mm / s.

[0031] After the first laser engraving process, the platform of the laser engraving machine is lowered by 0.1~1mm along the Z-axis before the second laser engraving process is performed.

[0032] The patterning of the patterned zinc cobalt fluoride-doped fluorinated graphene includes interdigitated patterns; in the interdigitated patterns, the width of the interdigitates is 1~5mm, the length of the interdigitates is 4~20mm, and the gap between the interdigitates is 0.5~2mm.

[0033] In a second aspect, the present invention provides a patterned zinc cobalt fluoride-doped fluorinated graphene, which is prepared by the aforementioned method for preparing patterned zinc cobalt fluoride-doped fluorinated graphene.

[0034] In a third aspect, the present invention provides an application of patterned zinc cobalt fluoride-doped fluorinated graphene in a micro supercapacitor, wherein the patterned zinc cobalt fluoride-doped fluorinated graphene is used to fabricate electrode materials in a micro supercapacitor.

[0035] Optionally, the fabrication steps of the electrode material for the micro supercapacitor include:

[0036] First, using conductive silver paste as a current collector, copper foil is connected to the patterned zinc cobalt fluoride-doped fluorinated graphene to form an electrode, and then heated and cured at 80~200℃ for 5~120min.

[0037] Secondly, insulating tape is used to cover the copper foil;

[0038] Then, the gel electrolyte is uniformly coated on the patterned zinc fluoride-doped fluorinated graphene surface with a coating thickness of 300~1000μm, and left to stand for 8~24h to obtain a conductive electrode.

[0039] Finally, insulating tape is used to cover the conductive electrodes and the copper foil to obtain the electrode material of the encapsulated micro supercapacitor.

[0040] The application of the technical solution of the present invention has at least the following beneficial effects:

[0041] (1) The present invention provides a method for preparing patterned zinc cobalt fluoride-doped fluorinated graphene, which can produce patterned zinc cobalt fluoride-doped fluorinated graphene electrode materials with good capacitance characteristics and large area-to-capacitance ratio. Specifically, the zinc cobalt fluoride used in step S1 of the present invention has a spinel structure, and its molecular formula can be represented as Zn. 2+ [Co 3+ Co 3+ O4, of which Zn 2+ Occupying the octahedral interstices of the spinel structure, half of the Co 3+ Occupying the tetrahedral interstices of the spinel structure, the other half of Co 3+ Occupying the octahedral interstices of the spinel structure. This special spinel structure can generate a large number of oxygen vacancies; and the large number of oxygen vacancies can significantly reduce the electrode internal resistance of patterned zinc fluorinated cobalt oxide-doped fluorinated graphene electrode materials, improve conductivity, and enable electrons to transfer rapidly during fast charge and discharge, thus allowing more electrons to pass through the active sites Co. 3+ To achieve active site Co 3+ The electrode material's area-to-capacitance ratio is fully utilized, resulting in better capacitance characteristics. Furthermore, in step S1, the present invention combines zinc cobalt fluoride, diamine monomer, and dianhydride monomer in a polar organic solvent, specifying that the dianhydride monomer and / or diamine monomer are fluorinated monomers. This facilitates the formation of a zinc cobalt fluoride-doped fluorinated polyamic acid composite resin. Simultaneously, the formed zinc cobalt fluoride-doped fluorinated polyamic acid composite resin has suitable viscosity and solid content, ensuring uniform dispersion of the zinc cobalt fluoride for subsequent formation of a patterned zinc cobalt fluoride-doped fluorinated graphene electrode material with good conductivity. Further, in step S2, the present invention obtains a uniformly structured zinc cobalt fluoride-doped fluorinated polyimide film through coating and stepped heating heat treatment. Further, in step S3, the exfoliated film is treated with a laser, utilizing the high energy density of the laser to induce pyrolysis of the polymer backbone in the fluorinated polyimide in a very short time, forming patterned zinc cobalt fluoride-doped fluorinated graphene. In addition, compared with the direct fluorination method and the mechanical stripping method, the present invention combines steps S1 to S3, which not only has a simple preparation process, high efficiency and low cost, but also does not require the use of the high-risk reagent fluorine gas.

[0042] (2) In the preparation step of zinc fluoride cobaltate of the present invention, excess water and ethanol in the zinc fluoride cobaltate precursor are removed by drying treatment; then, by annealing treatment, some oxygen ions in the zinc fluoride cobaltate precursor combine to form oxygen molecules and escape from the zinc fluoride cobaltate precursor, thereby forming oxygen vacancies in the zinc fluoride cobaltate precursor; further, by reducing conditions in chemical reduction treatment, the remaining oxygen ions in the zinc fluoride cobaltate precursor combine with hydrogen ions in NaBH4 solution to form water and escape from the zinc fluoride cobaltate precursor, thereby forming more oxygen vacancies in the zinc fluoride cobaltate precursor, thus obtaining zinc fluoride cobaltate with a large number of oxygen vacancies.

[0043] (3) When the diamine monomer used in this invention is a fluorine-free rigid aromatic diamine monomer, or when the dianhydride monomer used is a fluorine-free rigid aromatic dianhydride monomer, a fluorinated polyamic acid composite resin with extremely high aromatic carbon content can be formed through the polycondensation reaction in step S1. Its chemical structure is very close to the benzene ring structure of graphite, exhibiting good rigidity and thermal stability. After the fluorinated polyamic acid composite resin forms a fluorinated polyimide film in step S2, its rigidity and thermal stability are further improved. During the laser treatment process in step S3, the fluorinated polyimide film... Non-carbon elements (such as O, N, and H) are mainly removed as volatile small molecules, while aromatic carbon skeletons are more easily recombined into sp² hybrid graphene, thus forming highly conductive fluorinated graphene. Due to the rigidity and thermal stability of the fluorinated polyimide film, during laser processing, the aromatic carbon skeleton on the surface of the fluorinated polyimide film first recombines into sp² hybrid graphene, while the aromatic carbon skeleton at the bottom layer of the fluorinated polyimide film is an incompletely carbonized intermediate. This incompletely carbonized intermediate then combines with the recombined sp² hybrid graphene to form… The strong physical interlocking and chemical bonding (CC bond) structure greatly enhances the bonding force between the surface graphene and the underlying layer, resulting in fluorinated graphene with excellent bending and folding resistance. Furthermore, during laser processing, the laser energy is concentrated within the area covered by the laser spot on the fluorinated polyimide film, causing the fluorinated polyimide film in that area to directly recombine into sp² hybridized graphene. Outside this area, the fluorinated polyimide film receives less laser energy, and due to the good rigidity and thermal stability of the fluorinated polyimide film... The fluorinated polyimide film outside the laser-treated area remains intact, thus enabling the formation of finely patterned zinc cobalt fluorinated graphene after laser processing. This meets the patterning precision requirements of micro / nanoelectronic devices. Furthermore, during laser processing, chemical bond breaking and gas generation occur simultaneously within the area covered by the laser spot on the fluorinated polyimide film. The gas escapes uniformly, resulting in a uniform and interconnected three-dimensional porous network in the final patterned zinc cobalt fluorinated graphene. This network structure not only provides a large specific surface area but also ensures the high specific surface area of ​​Co.3+ Rapid ion transport further enhances conductivity.

[0044] (4) The stepped heating heat treatment used in this invention includes a first heating stage, a second heating stage, and a third heating stage with the heating temperature increasing sequentially. In the first heating stage, a medium-low temperature combined with an appropriate heating time is used to facilitate the removal of polar organic solvents in the coating and prevent the generation of bubbles and defects. In the second heating stage, a medium-high temperature combined with an appropriate heating time is used to facilitate the imidization of fluorinated polyamic acid. Within this temperature range, the amic acid structure of polyamic acid undergoes rapid cyclization and dehydration to form an imide ring. With the formation of the imide ring, the molecular chain changes from flexible polyamic acid to a rigid polyimide film, and the film begins to shrink and tends to become dense. This is the core stage of the entire imidization process. In the third heating stage, a high temperature combined with an appropriate heating time is used to further cyclize the few unreacted amic acid groups at high temperature, improve the degree of imidization (close to 100%), improve thermal stability and chemical stability, thereby consolidating and strengthening the formed polyimide main chain structure and improving the thermal stability and insulation of the material.

[0045] (5) The laser processing used in this invention includes a first laser engraving process and a second laser engraving process. Through the two laser engraving processes, the polyimide molecular chain is rapidly pyrolyzed and gas is released to form pores. At the same time, carbon atoms rearrange into sp² hybrid three-dimensional interconnected graphene networks, thereby directly converting insulating polyimide into clear and stable patterned zinc fluorinated cobalt oxide doped fluorinated graphene.

[0046] (6) The patterned zinc cobalt oxide-doped fluorinated graphene prepared by the present invention can be used as an electrode material for micro supercapacitors, providing the possibility for energy storage of miniaturized, flexible, high-energy-density and low-cost wearable electronic products.

[0047] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0048] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0049] Figure 1 The miniature supercapacitors prepared in Examples 1-4 and Comparative Examples 1-3 are used at a current density of 0.5 mA / cm². 2The constant current charge-discharge curve at that time. Detailed Implementation

[0050] 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 the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0051] Example 1:

[0052] A method for preparing patterned zinc fluorinated cobaltate-doped fluorinated graphene includes:

[0053] Step S1: Add zinc fluorocobaltate and diamine monomer to a polar organic solvent (specifically N,N-dimethylacetamide) and stir until homogeneous. Then, while stirring, add dianhydride monomer in batches (specifically, in four batches: the first batch accounts for 30% of the total dianhydride monomer, the second batch accounts for 30%, the third batch accounts for 30%, and the fourth batch accounts for 10%) to form a reaction system. The system undergoes a polycondensation reaction at a controlled temperature of 0-5°C until the viscosity reaches 50,000-250,000 centipoise (specifically 120,000 centipoise) to obtain a zinc fluorocobaltate-doped fluorinated polyamic acid composite resin. The solid content of the composite resin is adjusted to 12%-25% (specifically 18%) using the polar organic solvent.

[0054] Wherein, the dianhydride monomer and / or the diamine monomer are fluorinated monomers; the molar ratio of the dianhydride monomer to the diamine monomer is 0.95:1 to 1.1:1 (specifically 1.05:1); the dianhydride monomer is 4,4'-(hexafluoroisopropyl) bis(phthalic anhydride) monomer; the diamine monomer is 4,4'-diaminodiphenyl ether and p-phenylenediamine in a molar ratio of 2:3; in the reaction system, the mass percentage of the zinc fluorocobaltate is 1% to 12% (specifically 5%).

[0055] Step S2: The composite resin is coated onto a carrier (specifically a glass plate) to form a coating; the thickness of the coating is 25~150μm (specifically 50μm); specifically, it is coated by scraping with a doctor blade; the coating is subjected to a stepped heating heat treatment to obtain a fluorinated polyimide film doped with zinc fluorine cobaltate; the film is cooled, then soaked in water, and then peeled off from the carrier;

[0056] Step S3: The peeled film is laser-processed to form patterned zinc cobalt fluoride-doped fluorinated graphene.

[0057] The preparation steps of the zinc fluorocobaltate include:

[0058] Zinc source, cobalt source, fluorine source, precipitant and deionized water are mixed in the required molar ratio of 1:1:2~6:3~12:1776 (the specific molar ratio is 1:2:5:8:1776), and after hydrothermal treatment, zinc fluoride cobaltate precursor is obtained.

[0059] After cooling, the zinc cobalt fluoride precursor is rinsed at least five times each with deionized water and anhydrous ethanol.

[0060] The rinsed zinc cobalt fluoride precursor was subjected to drying, annealing and chemical reduction treatment in sequence to obtain zinc cobalt fluoride with oxygen vacancies and a particle size of 20~200nm.

[0061] The zinc source includes zinc nitrate; the cobalt source includes cobalt nitrate; the fluorine source includes ammonium fluoride; the precipitant includes urea; and the hydrothermal treatment uses a hydrothermal temperature of 120~180℃ (specifically 120℃) and a hydrothermal time of 3~24h (specifically 6h).

[0062] The drying process uses a drying temperature of 60~90℃ (specifically 70℃) and a drying time of 8~24h (specifically 12h).

[0063] The annealing process is carried out under air conditions, with an annealing temperature of 400~800℃ (specifically 600℃) and an annealing time of 3~8h (specifically 5h).

[0064] The reducing agent used in the chemical reduction treatment is NaBH4 solution, and the reduction time is 3-5 hours (specifically 4 hours); the molar concentration of the NaBH4 solution is 0.2-1.0 mol / L (specifically 0.5 mol / L); and the mass of the zinc fluorocobaltate precursor in each liter of the NaBH4 solution is 25-75 g (specifically 50 g).

[0065] The stepped heating heat treatment includes a first heating stage, a second heating stage, and a third heating stage with the heating temperature increasing sequentially. Specifically, in the first heating stage, the heating temperature is 60~100℃ (specifically 100℃), and the heating time is 10~60min (specifically 10min); in the second heating stage, the heating temperature is 150~250℃ (specifically 200℃), and the heating time is 10~120min (specifically 15min); in the third heating stage, the heating temperature is 280~350℃ (specifically 300℃), and the heating time is 10~60min (specifically 10min).

[0066] The heating rate used from the first heating stage to the second heating stage is 5~15℃ / min (specifically 5℃ / min);

[0067] The heating rate used from the second heating stage to the third heating stage is 5~15℃ / min (specifically 5℃ / min).

[0068] The laser processing involves placing the film on the platform of a CO2 laser engraving machine and performing a first laser engraving and a second laser engraving according to the drawn interdigitated pattern. The power used for the first laser engraving and the second laser engraving is 3~10W (specifically 8.7W), and the engraving speed is 80~300mm / s (specifically 200mm / s).

[0069] After the first laser engraving process, the platform of the laser engraving machine is lowered by 0.1~1mm (specifically 0.5mm) along the Z-axis before the second laser engraving process is performed.

[0070] The patterning of the patterned zinc cobalt fluoride-doped fluorinated graphene includes an interdigitated pattern; in the interdigitated pattern, the width of the interdigitates is 1~5mm (specifically 2mm), the length of the interdigitates is 4~20mm (specifically 6mm), the gap between the interdigitates is 0.5~2mm (specifically 0.5mm), and the effective area of ​​the interdigitated pattern is 1.2cm². 2 .

[0071] The patterned zinc fluorinated cobaltate-doped fluorinated graphene prepared in Example 1 is used as an electrode material in a micro supercapacitor. The fabrication steps of the electrode material for the micro supercapacitor include:

[0072] First, using conductive silver paste as a current collector, copper foil was connected to the patterned zinc fluoride-doped fluorinated graphene to form an electrode, and then cured at 80~200℃ (specifically 80℃) for 5~120 min (specifically 80 min). The conductive silver paste was purchased from Dongguan Saiqin Electronics Technology Co., Ltd., part number 01L-2211D. The copper foil was purchased from China Jiuou Metal Materials Co., Ltd. (the copper foil was purchased from China Jiuou Metal Materials Co., Ltd., with a width of 3 mm and a thickness of 50 μm).

[0073] Secondly, insulating tape (specifically polyimide tape) is used to cover the copper foil to protect it from corrosion by the acidic gel electrolyte.

[0074] Then, a gel electrolyte (PVA / H2SO4) is uniformly coated onto the patterned zinc cobalt fluoride-doped fluorinated graphene surface with a coating thickness of 300~1000μm (specifically 300μm), and left to stand for 8~24h (specifically 12h) to ensure that the gel electrolyte fully penetrates into the porous structure of the patterned zinc cobalt fluoride-doped fluorinated graphene, thereby obtaining a conductive electrode with stable electrochemical performance;

[0075] Finally, insulating tape is used to cover the conductive electrodes and the copper foil to obtain the encapsulated electrode material of the micro supercapacitor, preventing the evaporation of moisture in the gel electrolyte.

[0076] The preparation method of PVA / H2SO4 gel electrolyte is as follows: 3 ml of concentrated sulfuric acid and 3 g of polyvinyl alcohol (PVA) are added to 30 ml of deionized water and stirred at a constant speed. The PVA is completely dissolved into a transparent solution by water bath heating at a constant temperature of 82℃. The solution is then cooled to room temperature to obtain the PVA / H2SO4 gel electrolyte.

[0077] Example 2:

[0078] Unlike Example 1, in the reaction system of step S1, the mass percentage of zinc fluorocobaltate is 3%.

[0079] Example 3:

[0080] Unlike Example 1, the diamine monomer used in step S1 is all 4,4'-bis(2-trifluoromethyl-4-aminophenoxy)diphenyl ether.

[0081] Example 4:

[0082] Unlike Example 1, the diamine monomer used in step S1 is all 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl.

[0083] Comparative Example 1:

[0084] Unlike Example 1, the dianhydride monomer used in step S1 is pyromellitic dianhydride.

[0085] Comparative Example 2:

[0086] Unlike Example 1, in step S1, the amount of zinc fluoride cobaltate is adjusted to zero, that is, zinc fluoride cobaltate is not used.

[0087] Comparative Example 3:

[0088] Unlike Comparative Example 2, the laser processing in step S3 cancels the second laser engraving process.

[0089] The micro supercapacitors prepared in Examples 1-4 and Comparative Examples 1-3 were tested for areal capacitance and energy density. The test results are shown in Table 1.

[0090] The areal capacitance test is as follows: The areal capacitance of the micro supercapacitor is calculated using the constant current charge-discharge method. Specifically, it is represented by expression (A1):

[0091] (A1);

[0092] In expression (A1), This indicates the areal capacitance of a micro supercapacitor. Indicates current density, It is the discharge time. This represents the area of ​​the electrode patterning. This represents the window voltage.

[0093] The energy density test is as follows: First, the areal capacitance of the micro supercapacitor is calculated using the constant current charge-discharge method. Then Substituting into expression (A2), the energy density is calculated as follows:

[0094] (A2);

[0095] In expression (A2), E This indicates the energy density of a micro supercapacitor.

[0096] Table 1. Test results of areal capacitance and energy density performance.

[0097]

[0098] As shown in Table 1, compared with Comparative Examples 1-3, the micro supercapacitors prepared by Examples 1-4 of this invention all exhibit higher areal capacitance and energy density.

[0099] By comparing Example 1 and Comparative Example 1, it is evident that the micro supercapacitors prepared in Comparative Example 1 exhibit significantly reduced areal capacitance and energy density. This is because unfluorinated zinc cobalt oxide was used in Comparative Example 1, which lacks a spinel structure capable of generating a large number of oxygen vacancies. Consequently, it cannot significantly reduce the electrode internal resistance of the electrode material, resulting in decreased conductivity and thus a significant reduction in areal capacitance and energy density.

[0100] Comparing Example 1 and Comparative Example 2, it is evident that the micro supercapacitors prepared in Comparative Example 2 exhibit significantly reduced areal capacitance and energy density. This is because the amount of zinc fluorocobaltate used in Comparative Example 2 is zero, which fails to significantly reduce the electrode internal resistance of the electrode material, resulting in decreased conductivity and consequently, a significant decrease in areal capacitance and energy density.

[0101] Comparing Comparative Examples 2 and 3, it is evident that the micro supercapacitors prepared in Comparative Example 3 exhibited a further decrease in areal capacitance and energy density. This is because, in Comparative Example 3, omitting the second laser engraving process made it difficult to completely pyrolyze the polymer backbone of the fluorinated polyimide into fluorinated graphene, leading to a decrease in conductivity and electrochemical activity, which in turn further reduced areal capacitance and energy density. In contrast, Comparative Example 2 combined the first and second laser engraving processes, which synergistically promoted the complete pyrolysis of the polymer backbone in the fluorinated polyimide, effectively repairing defects in the fluorinated graphene and increasing the sp² carbon content, thereby enhancing its conductivity and electrochemical activity, resulting in an increase in areal capacitance and energy density.

[0102] By comparing Example 1 and Example 2, it is known that by appropriately increasing the amount of zinc fluoride cobaltate in Example 1, more zinc fluoride cobaltate is densely attached and interspersed in the three-dimensional porous network of fluorinated graphene, thereby further enhancing conductivity and causing the micro supercapacitors to exhibit higher areal capacitance and energy density.

[0103] Comparing Examples 1 and 3-4, it is evident that, unlike Examples 3-4 which only used fluorinated diamine monomers, Example 1 combined a specific molar ratio of the fluorinated diamine monomer 4,4'-bis(2-trifluoromethyl-4-aminophenoxy)diphenyl ether and the fluorine-free rigid aromatic diamine monomer p-phenylenediamine. Through the polycondensation reaction in step S1, a fluorinated polyamic acid composite resin with extremely high aromatic carbon content was formed. Its chemical structure is very close to the benzene ring structure of graphite, exhibiting good rigidity and thermal stability. During laser processing, non-carbon elements (such as O, N, H) in the fluorinated polyimide film are mainly removed in the form of volatile small molecules, while the aromatic carbon skeleton is more easily directly recombined into sp... 2Hybridized graphene forms highly conductive fluorinated graphene. Specifically, during laser processing, chemical bond breaking and gas generation occur simultaneously within the area of ​​the fluorinated polyimide film covered by the laser spot. The gas escapes uniformly, resulting in a uniform and interconnected three-dimensional porous network in the final patterned zinc cobalt fluorinated graphene. This network structure not only provides a huge specific surface area but also ensures the high conductivity of Co. 3+ The rapid transport of ions further enhances conductivity, resulting in higher areal capacitance and energy density in micro supercapacitors.

[0104] See Figure 1 The micro supercapacitors prepared in Examples 1-4 and Comparative Examples 1-3 were calculated using expression (A1) at a current density of 0.5 mA / cm². 2 The constant current charge-discharge curve at that time. Figure 1 It is known that the micro supercapacitor prepared in Example 1 operates at a current density of 0.5 mA / cm². 2 The constant current charge-discharge time is the longest, exhibiting better specific capacitance performance.

[0105] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for preparing a patterned fluorine-containing zinc cobaltate doped fluorinated graphene, characterized in that, include: Step S1: Add zinc fluorocobaltate and diamine monomer to a polar organic solvent and stir to mix thoroughly; Subsequently, dianhydride monomers were added in batches under stirring to form a reaction system. Following a polycondensation reaction, the viscosity of the reaction system reached 50,000–250,000 centipoise, yielding a fluorinated polyamic acid composite resin doped with zinc fluorocobaltate. The solid content of the composite resin was adjusted to 12%–25% using the polar organic solvent. Wherein, the dianhydride monomer and / or the diamine monomer are fluorine-containing monomers; the molar ratio of the dianhydride monomer to the diamine monomer is 0.95:1 to 1.1:1; in the reaction system, the mass percentage of the zinc fluorocobaltate is 1% to 12%; Step S2: The composite resin is coated onto the carrier to form a coating; the coating is subjected to a stepped heating heat treatment to obtain a fluorinated polyimide film doped with zinc fluorine cobalt oxide; the film is cooled, then soaked in water, and then peeled off from the carrier. Step S3: The peeled film is laser-processed to form patterned zinc fluorine cobalt oxide-doped fluorinated graphene; the laser processing includes a first laser engraving process and a second laser engraving process; the power used in the first laser engraving process and the second laser engraving process is 3~10W and the engraving speed is 80~300mm / s.

2. The method of claim 1, wherein the patterned fluorine-containing zinc cobaltate-doped fluorographene is prepared by the steps of: The preparation steps of the zinc fluorocobaltate include: Zinc source, cobalt source, fluorine source, precipitant and deionized water are mixed in the required molar ratio of 1:2:2~6:3~12:1776 and then subjected to hydrothermal treatment to obtain zinc fluoride cobaltate precursor. After cooling, the zinc cobalt fluoride precursor is rinsed at least five times each with deionized water and anhydrous ethanol. The rinsed zinc fluorinated cobaltate precursor was subjected to drying, annealing and chemical reduction treatment in sequence to obtain zinc fluorinated cobaltate with oxygen vacancies. Wherein, the zinc source includes zinc nitrate; the cobalt source includes cobalt nitrate; the fluorine source includes ammonium fluoride; the precipitant includes urea; and the hydrothermal treatment uses a hydrothermal temperature of 120~180℃ and a hydrothermal time of 3~24h. The drying process uses a drying temperature of 60~90℃ and a drying time of 8~24h. The annealing process is carried out under air conditions, with an annealing temperature of 400~800℃ and an annealing time of 3~8h. The reducing agent used in the chemical reduction treatment is NaBH4 solution, and the reduction time is 3-5 hours; the molar concentration of the NaBH4 solution is 0.2-1.0 mol / L; and the mass of the zinc fluorocobaltate precursor in each liter of the NaBH4 solution is 25-75 g.

3. The method for preparing patterned zinc fluoride-doped fluorinated graphene as described in claim 1, characterized in that, When the dianhydride monomer is a fluorinated dianhydride monomer, it includes 4,4'-(hexafluoroisopropyl)bisphthalic anhydride; Alternatively, when the dianhydride monomer is a fluorine-free rigid aromatic dianhydride monomer, it includes biphenyltetracarboxylic dianhydride or pyromellitic dianhydride.

4. The method for preparing patterned zinc fluorinated cobalt oxide-doped fluorinated graphene as described in claim 1, characterized in that, The diamine monomer is a fluorinated diamine monomer; or, the diamine monomer is a non-fluorinated rigid aromatic diamine monomer; or, the diamine monomer includes a fluorinated diamine monomer and a non-fluorinated rigid aromatic diamine monomer. The fluorinated diamine monomers include 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl or 4,4'-bis(2-trifluoromethyl-4-aminophenoxy)diphenyl ether; The fluorine-free rigid aromatic diamine monomers include at least one of 4,4'-diaminodiphenyl ether and p-phenylenediamine.

5. The method for preparing patterned zinc fluorinated cobalt oxide-doped fluorinated graphene as described in claim 1, characterized in that, The polar organic solvent includes any one of N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone.

6. The method for preparing patterned zinc fluoride-doped fluorinated graphene as described in claim 1, characterized in that, The thickness of the coating is 25~150μm; The stepped heating heat treatment includes a first heating stage, a second heating stage, and a third heating stage with the heating temperature increasing sequentially; wherein, in the first heating stage, the heating temperature is 60~100℃ and the heating time is 10~60min; in the second heating stage, the heating temperature is 150~250℃ and the heating time is 10~120min; and in the third heating stage, the heating temperature is 280~350℃ and the heating time is 10~60min. The heating rate used from the first heating stage to the second heating stage is 5~15℃ / min; The heating rate used from the second heating stage to the third heating stage is 5~15℃ / min.

7. The method for preparing patterned zinc fluoride-doped fluorinated graphene as described in claim 1, characterized in that, After the first laser engraving process, the platform of the laser engraving machine is lowered by 0.1~1mm along the Z-axis before the second laser engraving process is performed. The patterning of the patterned zinc cobalt fluoride-doped fluorinated graphene includes interdigitated patterns; in the interdigitated patterns, the width of the interdigitates is 1~5mm, the length of the interdigitates is 4~20mm, and the gap between the interdigitates is 0.5~2mm.

8. A patterned zinc fluoride-doped fluorinated graphene, characterized in that, The patterned zinc fluoride-doped fluorinated graphene was prepared using any one of the methods described in claims 1 to 7.

9. The application of patterned zinc cobalt fluoride-doped fluorinated graphene as described in claim 8 in micro supercapacitors, characterized in that, The patterned zinc cobalt fluoride-doped fluorinated graphene is used to fabricate electrode materials in micro supercapacitors.

10. The application of patterned zinc fluoride-doped fluorinated graphene as described in claim 9 in micro supercapacitors, characterized in that, The steps for fabricating the electrode material of the micro supercapacitor include: First, using conductive silver paste as a current collector, copper foil is connected to the patterned zinc cobalt fluoride-doped fluorinated graphene to form an electrode, and then heated and cured at 80~200℃ for 5~120min. Secondly, insulating tape is used to cover the copper foil; Then, the gel electrolyte is uniformly coated on the patterned zinc fluoride-doped fluorinated graphene surface with a coating thickness of 300~1000μm, and left to stand for 8~24h to obtain a conductive electrode. Finally, insulating tape is used to cover the conductive electrodes and the copper foil to obtain the electrode material of the encapsulated micro supercapacitor.

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