Directional preparation process for porous structure of composite electrode of supercapacitor
By constructing a hierarchical porous structure using directional ice template technology and gradient freeze-drying process, and combining it with a heterojunction composite of MXene, nitrogen-doped carbon source and transition metal chalcogenides, the problems of unreasonable pore structure design and difficulty in balancing conductivity and stability in supercapacitor electrode materials are solved, achieving high energy storage performance and low-cost large-scale production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HONEYCOMB ACTIVATED CARBON CO LTD
- Filing Date
- 2026-01-16
- Publication Date
- 2026-05-05
AI Technical Summary
Existing supercapacitor electrode materials suffer from problems such as unreasonable pore structure design, difficulty in balancing conductivity and structural stability, and complex and costly manufacturing processes, making it difficult to meet the needs of high-end energy storage scenarios.
A hierarchical porous structure was constructed using directional ice template technology and gradient freeze-drying process. A highly conductive network was built by using MXene and nitrogen-doped carbon source. A carbon-enhanced porous structure was derived from a metal-organic framework. A heterojunction composite structure was formed by in-situ growth of transition metal chalcogenides. Surface modification treatment was performed to optimize the hydrophilicity and electrolyte wettability of the material.
A hierarchical porous structure with directional arrangement was achieved, which improved the ion diffusion rate and electron transport efficiency, enhanced the cycle stability and capacitance performance of the material, reduced production costs, and made it suitable for different energy storage scenarios.
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Figure CN121983442A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of supercapacitor technology, and in particular to a process for the directional fabrication of porous structures for supercapacitor composite electrodes. Background Technology
[0002] Supercapacitors, as novel energy storage devices, have broad application prospects in new energy vehicles, smart grids, and portable electronic devices due to their advantages such as fast charging and discharging rates, long cycle life, and environmental friendliness. Electrode materials, as the core components of supercapacitors, directly determine capacitance performance, ion transport efficiency, and cycle stability through their structural design. Developing electrode materials that combine high specific surface area, rational pore structure, and excellent conductivity has become a core research direction in the industry.
[0003] While significant progress has been made in the research and development of supercapacitor electrode materials, several technical bottlenecks remain. Firstly, the pore structure design is often flawed. Traditional electrode materials are mostly random porous structures, lacking a directionally arranged pore system. This results in tortuous ion transport paths, high diffusion resistance, and severe capacitance decay at high current densities, making it difficult to meet the demands of high-power energy storage. Secondly, a single pore size cannot simultaneously balance ion storage and transport efficiency. Microporous materials have high specific surface areas but slow ion diffusion, while macroporous materials offer fast ion transport but limited storage capacity. The synergistic design of hierarchical pore structures still requires optimization.
[0004] Secondly, balancing conductivity and structural stability is difficult in electrode materials. During the composite process of conductive components such as MXene and carbon materials with energy storage components such as metal-organic frameworks and transition metal compounds, poor interfacial compatibility easily leads to agglomeration, hindering electron transport. Furthermore, during long-term charge-discharge cycles, the composite structure is prone to capacitance decay due to volume expansion and structural collapse, resulting in insufficient cycle stability. In addition, most composite electrode materials have poor surface hydrophilicity and electrolyte wettability, further restricting ion migration rates and affecting capacitance performance.
[0005] Furthermore, existing preparation processes have significant limitations. Traditional porous material preparation methods, such as template methods and foaming methods, struggle to precisely control the orientation and size distribution of pores, and are complex and costly, hindering large-scale production. While directional pore preparation technologies, such as ice template methods, can achieve directional pore arrangement, pore structure collapse is prone to occur during freezing rate control and ice crystal sublimation, leading to a decrease in material porosity and structural integrity. Simultaneously, subsequent carbonization, activation, and composite modification processes lack synergistic design, making it difficult to simultaneously optimize pore structure, conductivity, and energy storage performance.
[0006] Finally, the overall performance of electrode materials needs improvement. Existing products generally suffer from low specific capacitance, insufficient high-rate performance, and short cycle life, making it difficult to meet the dual requirements of energy density and power density in high-end energy storage scenarios. Therefore, developing a fabrication process capable of precisely constructing directional hierarchical porous structures, optimizing component interface bonding, and improving conductivity and stability to achieve a breakthrough in the overall performance of supercapacitor electrode materials has become a pressing technical challenge for the industry and is of great significance for promoting the industrial application of supercapacitors. Summary of the Invention
[0007] The present invention proposes a directional fabrication process for porous structures of supercapacitor composite electrodes to solve the problems mentioned in the prior art.
[0008] To achieve the above objectives, the present invention employs the following technical solution: a process for directional fabrication of porous structures for supercapacitor composite electrodes, comprising the following steps: S1. Preparation of precursor solution: Mix MXene dispersion, nitrogen-doped carbon source, metal-organic framework precursor and pore structure guiding agent in a preset ratio, and add crosslinking modifier and surfactant under stirring to obtain a uniform and stable precursor composite solution. S2. Directional ice template molding: The precursor composite solution is injected into the mold and directional solidification is carried out using unidirectional freezing technology, with the freezing rate controlled at 0.5-10 mm / min and the freezing temperature at -196℃ to -40℃. S3. Freeze-drying and demolding: Freeze-dry the directionally solidified sample at -80℃ to -40℃ and a vacuum of 1-50Pa for 12-72h, sublimate to remove the ice crystal template, and obtain the precursor aerogel skeleton with oriented channels. S4. Heat treatment carbonization and activation: The precursor aerogel skeleton is placed in a protective atmosphere and heated to 600-1000℃ at a heating rate of 1-10℃ / min for 1-6h. Then, activation gas is introduced and activated at 700-900℃ for 0.5-3h to obtain a carbonized intermediate with a hierarchical porous structure. S5. In-situ growth composite: The carbonized intermediate is immersed in a precursor solution containing transition metal salts and chalcogen source, and hydrothermal reaction is carried out at 120-220℃ for 4-24 hours to allow the transition metal chalcogen compound to grow in-situ on the inner wall of the directional channel to form a heterojunction composite structure. S6. Surface modification treatment: Plasma surface modification or chemical vapor deposition treatment is performed on the heterojunction composite structure to construct a conductive reinforcement layer and hydrophilic functional groups on the pore surface, thereby obtaining a porous structure of supercapacitor composite electrode.
[0009] Furthermore, in step S1, the concentration of the MXene dispersion is 0.5-20 mg / mL, and the MXene is selected from... One or more of the following are selected: nitrogen-doped carbon source is selected from melamine, dicyandiamide, urea, polydopamine, polyaniline, chitosan, and the amount added is 50-500% of the mass of MXene; metal-organic framework precursor is selected from one or more of ZIF-8, ZIF-67, MIL-88, UiO-66, HKUST-1, and the amount added is 20-300% of the mass of MXene.
[0010] Further, in step S1, the pore structure guiding agent is selected from one or more of polyvinyl alcohol, polyethylene glycol, polyethylene oxide, sodium carboxymethyl cellulose, and sodium alginate, with a concentration of 0.1-10 wt%; the crosslinking modifier is selected from one or more of glutaraldehyde, epichlorohydrin, citric acid, boric acid, and genipin, with a mass ratio of 0.01-0.5:1 to the pore structure guiding agent; the surfactant is selected from one or more of sodium dodecyl sulfate, hexadecyltrimethylammonium bromide, Triton X-100, and Tween 80, with an addition amount of 0.01-2% of the total mass of the precursor composite solution.
[0011] Furthermore, in step S2, the unidirectional freezing technology adopts a bottom freezing method: the precursor composite solution is injected into a cylindrical mold with a top opening, the bottom of the mold is a high thermal conductivity metal plate and the side walls are made of heat insulation material; the bottom of the mold is in contact with a cold source, which is selected from one of liquid nitrogen cold bath, dry ice-ethanol cold bath, semiconductor refrigeration chip, and programmable temperature controlled freezing stage; the temperature of the cold source is controlled from -196℃ to -40℃ by adjusting the contact area between the cold source and the mold or the power of the cold source.
[0012] Furthermore, in step S3, the freeze-drying process employs a gradient temperature increase procedure: the first stage is maintained at -80℃ to -60℃ and a vacuum of 1-10 Pa for 4-12 hours; the second stage is heated to -40℃ to -30℃ at a rate of 0.5-2℃ / h and maintained for 4-24 hours at a vacuum of 5-20 Pa; the third stage is heated to 0-25℃ at a rate of 1-5℃ / h and maintained for 4-24 hours at a vacuum of 10-50 Pa; finally, a directional porous aerogel framework with a porosity of 85-98% and a pore size of 5-200 μm is obtained.
[0013] Further, in step S4, the protective atmosphere is selected from nitrogen, argon, or a mixture of nitrogen and hydrogen, with hydrogen comprising 3-10% of the mixture; the carbonization process employs a segmented heating program: pre-carbonization is performed by heating to 300-400℃ at a rate of 1-3℃ / min and holding for 0.5-2 hours, followed by complete carbonization by heating to 600-1000℃ at a rate of 2-5℃ / min and holding for 1-6 hours; the activation gas is selected from one or more of carbon dioxide, water vapor, and ammonia, with a flow rate of 50-500 mL / min; after carbonization and activation, the carbonization intermediate has a micropore diameter of 0.5-2 nm, a mesopore diameter of 2-50 nm, a macropore diameter of 50 nm-200 μm, and a specific surface area of 500-3000 m². 2 / g.
[0014] Furthermore, in step S5, the transition metal salt is selected from one or more of cobalt salt, nickel salt, iron salt, molybdenum salt, tungsten salt, and manganese salt, and its concentration in the precursor solution is 0.01-1 mol / L; the chalcogen source is selected from one or more of thiourea, thioacetamide, selenium powder, selenocysteine, tellurium powder, and sodium telluride, and its molar ratio with the transition metal salt is 1-10:1; the precursor solution also contains a structure regulator, which is selected from one or more of hexamethylenetetramine, urea, ammonium fluoride, and oxalic acid, and its concentration is 0.05-2 mol / L; after the hydrothermal reaction, the transition metal chalcogen compound is in the form of nanosheets, nanoflowers, or nanowires.
[0015] Furthermore, in step S6, the plasma surface modification treatment includes: treating with oxygen plasma for 10-300s, with a radio frequency power of 50-300W and an oxygen flow rate of 10-100sccm; or treating with nitrogen plasma for 10-300s, with a radio frequency power of 50-300W and a nitrogen flow rate of 10-100sccm; after treatment, the surface oxygen content is 5-20at%, and the nitrogen content is 2-15at.
[0016] Furthermore, in step S6, the chemical vapor deposition process includes: placing the heterojunction composite structure in a reaction chamber and introducing a mixture of carbon source gas and hydrogen gas; the carbon source gas is selected from one or more of methane, ethylene, acetylene, and benzene, with a flow rate of 5-100 sccm, and the hydrogen gas flow rate is 50-500 sccm; and depositing at 800-1100℃ for 5-60 min.
[0017] Furthermore, the performance parameters of the prepared porous structure are as follows: oriented pore orientation degree 70-95%, pore diameter 5-100 μm, pore length 0.5-10 mm; specific surface area 800-2500 m² / g. 2 / g, pore volume 0.5-3.0cm 3 / g; In a three-electrode system and 6MKOH electrolyte, the specific capacitance is 300-800F / g at a current density of 1A / g, and the capacitance retention rate is 70-95% at a current density of 50A / g; After 10,000 cycles at a current density of 10A / g, the capacitance retention rate is greater than 90%.
[0018] Compared with existing technologies, the beneficial effects of this invention are: First, this invention successfully constructs a hierarchical porous structure with directional arrangement through directional ice template technology and gradient freeze-drying process. Unidirectional freezing technology enables ice crystals to grow directionally along a temperature gradient. After gradient heating and freeze-drying, the resulting pores exhibit good orientation and structural integrity, effectively reducing obstacles to ion transport paths and enhancing ion diffusion rates. In the hierarchical porous structure, micropores, mesopores, and macropores work synergistically. Micropores provide abundant energy storage sites, while mesopores and macropores ensure rapid ion transport, balancing high specific surface area with excellent high-rate performance, thus solving the pain point of unreasonable pore structure design in traditional materials.
[0019] Secondly, this invention significantly improves the conductivity and structural stability of the material through multi-component synergistic composite and interface optimization. MXene and nitrogen-doped carbon source construct a highly conductive network, metal-organic frameworks derive carbon to enhance the porous structure and conductivity, and transition metal chalcogenides are grown in situ to form a heterojunction composite structure. The interfaces of each component are tightly bonded, effectively avoiding agglomeration. At the same time, the construction of the heterojunction structure and conductive reinforcement layer accelerates electron transport, reduces interface resistance, and the hierarchical porous structure provides buffer space for volume expansion, greatly improving the cycling stability of the material and solving the problem of balancing conductivity and stability in composite electrodes.
[0020] Furthermore, this invention optimizes the hydrophilicity and electrolyte wettability of the material through surface modification. Plasma modification introduces hydrophilic functional groups, and chemical vapor deposition constructs a conductive reinforcement layer. Under this dual effect, the surface hydrophilicity of the material is significantly improved, allowing the electrolyte to quickly and fully wet the interior of the channels, further reducing ion migration resistance and improving capacitor performance efficiency. In addition, the parameters of each process step are precisely controllable. The size, orientation, and proportion of hierarchical pore structures of the oriented channels can be flexibly adjusted through process parameters to adapt to the needs of different energy storage scenarios.
[0021] Finally, the preparation process of this invention has the advantages of simple operation, strong controllability, and ease of large-scale production. Each step is clearly defined, requiring no complex equipment or harsh reaction conditions. Standardized processes enable precise control of pore structure, component composition, and performance, effectively reducing production costs. The prepared electrode material exhibits excellent comprehensive performance, combining high specific capacitance, good high-rate performance, and cycle stability. It can meet the energy storage needs of various scenarios such as new energy vehicles and smart grids, promoting the upgrading and industrial application of supercapacitor technology, and possesses broad market prospects and social value. Attached Figure Description
[0022] Figure 1 This is a schematic block diagram of the directional fabrication process of the porous structure of the supercapacitor composite electrode proposed in this invention; Figure 2 A bar chart comparing the hole structure parameters of the embodiments and comparative examples. Figure 3 Line graph showing the effect of different freezing rates on channel orientation; Figure 4 This is a radar chart showing the comprehensive performance score of different surface modification methods in Example 2. Detailed Implementation
[0023] 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 some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0024] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. The invention will now be described in further detail with reference to the accompanying drawings.
[0026] Reference Figures 1 to 4A process for directional fabrication of porous structures for supercapacitor composite electrodes includes the following steps: S1. Preparation of precursor solution: Mix MXene dispersion, nitrogen-doped carbon source, metal-organic framework precursor and pore structure guiding agent in a preset ratio, and add crosslinking modifier and surfactant under stirring to obtain a uniform and stable precursor composite solution. S2. Directional ice template molding: The precursor composite solution is injected into the mold and directional solidification is carried out using unidirectional freezing technology. The freezing rate is controlled at 0.5-10 mm / min and the freezing temperature is from -196℃ to -40℃, so that the ice crystals grow directionally along the temperature gradient to form an ice template structure. S3. Freeze-drying and demolding: Freeze-dry the directionally solidified sample at -80℃ to -40℃ and a vacuum of 1-50Pa for 12-72h, sublimate to remove the ice crystal template, and obtain the precursor aerogel skeleton with oriented channels. S4. Heat treatment carbonization and activation: The precursor aerogel skeleton is placed in a protective atmosphere and heated to 600-1000℃ at a heating rate of 1-10℃ / min for 1-6h. Then, activation gas is introduced and activated at 700-900℃ for 0.5-3h to obtain a carbonized intermediate with a hierarchical porous structure. S5. In-situ growth composite: The carbonized intermediate is immersed in a precursor solution containing transition metal salts and chalcogen source, and hydrothermal reaction is carried out at 120-220℃ for 4-24 hours to allow the transition metal chalcogen compound to grow in-situ on the inner wall of the directional channel to form a heterojunction composite structure. S6. Surface modification treatment: Plasma surface modification or chemical vapor deposition treatment is performed on the heterojunction composite structure to construct a conductive reinforcement layer and hydrophilic functional groups on the pore surface, thereby obtaining a porous structure of supercapacitor composite electrode.
[0027] In this invention, in step S1, the concentration of the MXene dispersion is 0.5-20 mg / mL, and the MXene is selected from... One or more of the following are selected: nitrogen-doped carbon source is selected from melamine, dicyandiamide, urea, polydopamine, polyaniline, chitosan, and the amount added is 50-500% of the mass of MXene; metal-organic framework precursor is selected from one or more of ZIF-8, ZIF-67, MIL-88, UiO-66, HKUST-1, and the amount added is 20-300% of the mass of MXene.
[0028] In this invention, in step S1, the pore structure guiding agent is selected from one or more of polyvinyl alcohol, polyethylene glycol, polyethylene oxide, sodium carboxymethyl cellulose, and sodium alginate, with a concentration of 0.1-10 wt%; the crosslinking modifier is selected from one or more of glutaraldehyde, epichlorohydrin, citric acid, boric acid, and genipin, with a mass ratio of 0.01-0.5:1 to the pore structure guiding agent; the surfactant is selected from one or more of sodium dodecyl sulfate, hexadecyltrimethylammonium bromide, Triton X-100, and Tween 80, with an addition amount of 0.01-2% of the total mass of the precursor composite solution.
[0029] In this invention, in step S2, the unidirectional freezing technology adopts a bottom freezing method: the precursor composite solution is injected into a columnar mold with a top opening, the bottom of the mold is a high thermal conductivity metal plate and the side walls are made of heat insulation material; the bottom of the mold is in contact with a cold source, which is selected from one of liquid nitrogen cold bath, dry ice-ethanol cold bath, semiconductor refrigeration chip, and programmable temperature-controlled freezing stage; the temperature of the cold source is controlled from -196℃ to -40℃, and the ice crystal growth rate is controlled to 0.5-10mm / min by adjusting the contact area between the cold source and the mold or the power of the cold source, forming a layered ice crystal structure oriented along the axial direction.
[0030] In this invention, in step S3, the freeze-drying process employs a gradient heating procedure: the first stage is maintained at -80℃ to -60℃ and a vacuum of 1-10Pa for 4-12 hours; the second stage is heated to -40℃ to -30℃ at a rate of 0.5-2℃ / h and maintained for 4-24 hours at a vacuum of 5-20Pa; the third stage is heated to 0-25℃ at a rate of 1-5℃ / h and maintained for 4-24 hours at a vacuum of 10-50Pa; finally, a directional porous aerogel framework with a porosity of 85-98% and a pore size of 5-200μm is obtained.
[0031] In this invention, in step S4, the protective atmosphere is selected from nitrogen, argon, or a mixture of nitrogen and hydrogen, with hydrogen comprising 3-10% of the mixture. The carbonization process employs a segmented heating procedure: pre-carbonization is performed by heating to 300-400℃ at a rate of 1-3℃ / min and holding for 0.5-2 hours, followed by complete carbonization by heating to 600-1000℃ at a rate of 2-5℃ / min and holding for 1-6 hours. The activation gas is selected from one or more of carbon dioxide, water vapor, and ammonia, with a flow rate of 50-500 mL / min. After carbonization and activation, the carbonization intermediate has a micropore diameter of 0.5-2 nm, a mesopore diameter of 2-50 nm, a macropore diameter of 50 nm-200 μm, and a specific surface area of 500-3000 m². 2 / g.
[0032] In this invention, in step S5, the transition metal salt is selected from one or more of cobalt salt, nickel salt, iron salt, molybdenum salt, tungsten salt, and manganese salt, and its concentration in the precursor solution is 0.01-1 mol / L; the chalcogen source is selected from one or more of thiourea, thioacetamide, selenium powder, selenocysteine, tellurium powder, and sodium telluride, and its molar ratio with the transition metal salt is 1-10:1; the precursor solution also contains a structure regulator, which is selected from one or more of hexamethylenetetramine, urea, ammonium fluoride, and oxalic acid, and its concentration is 0.05-2 mol / L; after the hydrothermal reaction, the transition metal chalcogen compound is in the form of nanosheets, nanoflowers, or nanowires, with a thickness or diameter of 5-100 nm, and the loading is 10-200% of the mass of the carbonization intermediate.
[0033] In this invention, step S6, the plasma surface modification treatment includes: oxygen plasma treatment for 10-300s, radio frequency power of 50-300W, and oxygen flow rate of 10-100sccm; or nitrogen plasma treatment for 10-300s, radio frequency power of 50-300W, and nitrogen flow rate of 10-100sccm; after treatment, the surface oxygen content is 5-20at%, the nitrogen content is 2-15at%, and the water contact angle is reduced to 10-50°.
[0034] In this invention, step S6, the chemical vapor deposition process includes: placing the heterojunction composite structure in a reaction chamber, and introducing a mixture of carbon source gas and hydrogen gas; the carbon source gas is selected from one or more of methane, ethylene, acetylene, and benzene, with a flow rate of 5-100 sccm, and the hydrogen gas flow rate is 50-500 sccm; depositing at 800-1100℃ for 5-60 min, and depositing a graphene or graphene-like carbon layer with a thickness of 1-20 nm on the surface of the pores as a conductive reinforcement layer.
[0035] In this invention, the performance parameters of the prepared porous structure are as follows: orientation degree of oriented channels 70-95%, channel diameter 5-100 μm, channel length 0.5-10 mm; specific surface area 800-2500 m² / g. 2 / g, pore volume 0.5-3.0cm 3 / g; In a three-electrode system and 6MKOH electrolyte, the specific capacitance is 300-800F / g at a current density of 1A / g, and the capacitance retention rate is 70-95% at a current density of 50A / g; After 10,000 cycles at a current density of 10A / g, the capacitance retention rate is greater than 90%.
[0036] The specific embodiments of the present invention are further illustrated below: Example 1 Raw material preparation: Raw materials are selected and precisely formulated according to the scope defined in the claims: MXene is selected. A dispersion with a concentration of 5 mg / mL was prepared. Melamine was used as the nitrogen-doped carbon source, added at 200% of the MXene mass. ZIF-67 was used as the metal-organic framework precursor, added at 150% of the MXene mass. Polyvinyl alcohol was used as the pore structure guiding agent, and a 2 wt% aqueous solution was prepared. Glutaraldehyde was used as the crosslinking modifier, with a mass ratio of 0.1:1 to the pore structure guiding agent. Sodium dodecyl sulfate was used as the surfactant, added at 0.5% of the total mass of the precursor composite solution. Cobalt nitrate was used as the transition metal salt, and thiourea was used as the chalcogen source, with a molar ratio of 1:3. Hexamethylenetetramine was used as the structure regulator, with a concentration of 0.5 mol / L. Nitrogen was used as the protective atmosphere, and carbon dioxide was used as the activating gas at a flow rate of 200 mL / min. Acetylene was used as the carbon source gas for chemical vapor deposition, and hydrogen was used as the reducing gas, with flow rates of 30 sccm and 200 sccm, respectively.
[0037] Preparation step S1, precursor solution preparation: First, prepare Ti3C2T x The dispersion, melamine, ZIF-67 powder and polyvinyl alcohol aqueous solution were mixed in a preset ratio and stirred at 500 r / min for 30 min on a magnetic stirrer. Then, glutaraldehyde and sodium dodecyl sulfate were slowly added and stirred for another 60 min. During this period, an ultrasonic disperser was used to assist in the treatment for 20 min to ensure that the system was uniform and stable and free from particle agglomeration, thus obtaining the precursor composite solution.
[0038] S2. Directional Ice Template Forming: The precursor composite solution is injected into a columnar mold with an open top. The bottom of the mold is a copper high thermal conductivity metal plate, and the side walls are made of polyurethane thermal insulation material. The bottom of the mold is brought into contact with a liquid nitrogen cold bath, and the cold source temperature is controlled at -120℃. By adjusting the contact area between the mold and the cold bath, the ice crystal growth rate is controlled at 3mm / min, so that the ice crystals grow axially in a directional manner. This condition is maintained for directional solidification for 2 hours to form a layered ice crystal template structure.
[0039] S3. Freeze-drying and demolding: A gradient temperature program was used for freeze-drying. In the first stage, the temperature was maintained at -70℃ and 5Pa vacuum for 8 hours. In the second stage, the temperature was increased to -35℃ at a rate of 1℃ / h and maintained for 12 hours under a vacuum of 10Pa. In the third stage, the temperature was increased to 20℃ at a rate of 3℃ / h and maintained for 10 hours under a vacuum of 30Pa. The total drying time was 30 hours. The ice crystal template was removed by sublimation to obtain the precursor aerogel skeleton with oriented channels.
[0040] S4. Heat treatment carbonization and activation: The precursor aerogel framework is placed in a tube furnace and nitrogen is introduced as a protective atmosphere. A segmented heating carbonization program is adopted: the temperature is increased to 350℃ at a rate of 2℃ / min and held for 1h for pre-carbonization; then the temperature is increased to 800℃ at a rate of 3℃ / min and held for 3h for complete carbonization; then carbon dioxide activation gas is introduced and activated at 800℃ for 1.5h. After activation, the mixture is naturally cooled to room temperature to obtain a carbonized intermediate with a hierarchical porous structure.
[0041] S5. In-situ growth of composite: Cobalt nitrate, thiourea, and hexamethylenetetramine were dissolved in deionized water to prepare a precursor solution, wherein the concentration of cobalt nitrate was 0.2 mol / L. The carbonized intermediate was immersed in the precursor solution and transferred to a hydrothermal reactor, where it was reacted at 180°C for 12 h. After the reaction, the mixture was cooled to room temperature, and the sample was washed three times alternately with deionized water and ethanol. It was then dried in a vacuum drying oven at 60°C for 8 h, allowing the cobalt-sulfur compound to grow in situ on the inner wall of the directional channels to form a heterojunction composite structure.
[0042] S6. Surface modification treatment: Chemical vapor deposition is used to place the heterojunction composite structure in the chemical vapor deposition reaction chamber, and a mixture of acetylene and hydrogen gas is introduced. Deposition is carried out at 950℃ for 20 min, and a graphene-like carbon layer with a thickness of 5 nm is deposited on the surface of the channel as a conductive reinforcement layer, finally obtaining a porous structure of supercapacitor composite electrode.
[0043] Example 2: Raw material preparation: Raw materials are selected and precisely formulated according to the scope defined in the claims: MXene is selected. and A dispersion with a concentration of 10 mg / mL was prepared by mixing the following components at a mass ratio of 1:1: Polydopamine was selected as the nitrogen-doped carbon source, with an addition amount of 300% of the MXene mass; MIL-88 was selected as the metal-organic framework precursor, with an addition amount of 200% of the MXene mass; polyethylene glycol was selected as the pore structure guiding agent, and a 5 wt% aqueous solution was prepared; epichlorohydrin was selected as the crosslinking modifier, with a mass ratio of 0.2:1 to the pore structure guiding agent; hexadecyltrimethylammonium bromide was selected as the surfactant, with an addition amount of 1% of the total mass of the precursor composite solution; nickel sulfate was selected as the transition metal salt, and selenocysteine was selected as the chalcogen source, with a molar ratio of 1:5; urea was selected as the structure regulating agent, with a concentration of 1 mol / L; a mixture of nitrogen and hydrogen was selected as the protective atmosphere, with a hydrogen integral of 5%; water vapor and ammonia were selected as the activation gas, mixed at a volume ratio of 1:1, with a flow rate of 300 mL / min; and oxygen plasma and nitrogen plasma were used for plasma surface modification.
[0044] Preparation step S1, precursor solution preparation: Prepare Ti2CT... x With V2CT xThe mixed dispersion, polydopamine, MIL-88 powder and polyethylene glycol aqueous solution were mixed in a preset ratio and stirred at 600 r / min for 40 min. Epichlorohydrin and hexadecyltrimethylammonium bromide were added and stirred for another 90 min. During this period, ultrasonic dispersion was carried out for 30 min to ensure that each component was uniformly dispersed, thus obtaining a stable precursor composite solution.
[0045] S2. Directional Ice Template Forming: The precursor composite solution is injected into a columnar mold. The bottom of the mold is made of a high thermal conductivity aluminum metal plate, and the side walls are made of polystyrene insulation material. The bottom of the mold is brought into contact with a programmable temperature-controlled freezing stage, and the cold source temperature is controlled at -80℃. By adjusting the power of the freezing stage, the ice crystal growth rate is controlled at 5mm / min. Directional solidification is carried out for 3 hours to form an axially aligned ice crystal template structure.
[0046] S3. Freeze-drying and demolding: Gradient temperature freeze-drying was adopted. In the first stage, the temperature was maintained at -65℃ and 8Pa vacuum for 6 hours. In the second stage, the temperature was increased to -32℃ at a rate of 1.5℃ / h and maintained for 18 hours under a vacuum of 15Pa. In the third stage, the temperature was increased to 25℃ at a rate of 4℃ / h and maintained for 12 hours under a vacuum of 40Pa. The total drying time was 36 hours. Ice crystals were removed by sublimation to obtain a directional porous aerogel framework.
[0047] S4. Heat treatment carbonization and activation: The aerogel skeleton is placed in a tube furnace and a mixture of nitrogen and hydrogen is introduced as a protective atmosphere. The carbonization is carried out in stages: the temperature is increased to 380℃ at a rate of 1.5℃ / min and held for 1.5h for pre-carbonization; then the temperature is increased to 900℃ at a rate of 4℃ / min and held for 4h for complete carbonization; the activation gas is switched to a mixture of water vapor and ammonia and activated at 850℃ for 2h. After cooling, a hierarchical porous carbonized intermediate is obtained.
[0048] S5. In-situ growth of composite: Nickel sulfate, selenocysteine, and urea were dissolved in deionized water to prepare a precursor solution with a nickel sulfate concentration of 0.5 mol / L. The carbonized intermediate was immersed in the precursor solution and placed in a hydrothermal reactor, where it was reacted at 200°C for 18 hours. After the reaction, the mixture was cooled, washed three times, and vacuum dried at 60°C for 10 hours to allow the nickel-selenium compound to grow in situ on the inner wall of the pores, forming a heterojunction structure.
[0049] S6. Surface modification treatment: First, oxygen plasma treatment is used for 60s with a radio frequency power of 150W and an oxygen flow rate of 50sccm; then nitrogen plasma treatment is used for 80s with a radio frequency power of 200W and a nitrogen flow rate of 60sccm; oxygen-containing and nitrogen-containing functional groups are introduced into the surface of the pores to obtain a porous structure of supercapacitor composite electrode.
[0050] Example 3: Raw material preparation: Raw materials are selected and precisely formulated according to the scope defined in the claims: MXene is selected. and A dispersion with a concentration of 3 mg / mL was prepared by mixing the components in a 2:1 mass ratio. Chitosan was used as the nitrogen-doped carbon source, added at 150% of the MXene mass. UiO-66 was used as the metal-organic framework precursor, added at 100% of the MXene mass. Sodium carboxymethyl cellulose was used as the pore structure guiding agent, prepared as a 1 wt% aqueous solution. Citric acid was used as the crosslinking modifier, with a mass ratio of 0.08:1 to the pore structure guiding agent. Tween 80 was used as the surfactant, added at 0.3% of the total mass of the precursor composite solution. Ferric chloride was used as the transition metal salt, and tellurium powder was used as the chalcogen source, with a molar ratio of 1:4. Ammonium fluoride was used as the structure regulator, with a concentration of 0.3 mol / L. Argon was used as the protective atmosphere, and carbon dioxide and water vapor were mixed at a volume ratio of 2:1 with a flow rate of 150 mL / min as the activation gas. Surface modification was performed using a combination of chemical vapor deposition and plasma treatment.
[0051] Preparation step S1, precursor solution preparation: Nb2CT x With Mo2CT x The mixed dispersion, chitosan, UiO-66 powder and sodium carboxymethyl cellulose aqueous solution were mixed in a preset ratio and stirred at 400 r / min for 35 min. Citric acid and Tween 80 were added and stirred for another 70 min. The mixture was then ultrasonically dispersed for 25 min to obtain a uniform and stable precursor composite solution.
[0052] S2. Directional Ice Template Forming: The precursor composite solution is injected into a columnar mold. The bottom of the mold is made of stainless steel with high thermal conductivity, and the side walls are made of phenolic resin insulation material. The bottom of the mold is brought into contact with a dry ice-ethanol cold bath. The temperature of the cold source is controlled at -60℃, and the contact area of the cold bath is adjusted to make the ice crystal growth rate 2mm / min. Directional solidification is carried out for 2.5h to form a directional ice crystal template structure.
[0053] S3. Freeze-drying and demolding: Gradient temperature freeze-drying was carried out. In the first stage, the temperature was maintained at -75℃ and 3Pa vacuum for 10 hours. In the second stage, the temperature was increased to -38℃ at a rate of 0.8℃ / h and maintained for 16 hours under a vacuum of 8Pa. In the third stage, the temperature was increased to 18℃ at a rate of 2℃ / h and maintained for 8 hours under a vacuum of 25Pa. The total drying time was 34 hours, and a directional porous aerogel framework was obtained.
[0054] S4. Heat treatment carbonization and activation: The aerogel skeleton is placed in a tube furnace and argon is introduced as a protective atmosphere. The carbonization is carried out in stages: the temperature is increased to 320℃ at a rate of 2.5℃ / min and held for 0.8h for pre-carbonization; then the temperature is increased to 750℃ at a rate of 3.5℃ / min and held for 2.5h for complete carbonization; the activation gas is switched to a mixture of carbon dioxide and water vapor and activated at 780℃ for 1h. After cooling, a hierarchical porous carbonized intermediate is obtained.
[0055] S5. In-situ growth of composite: Ferric chloride, tellurium powder, and ammonium fluoride are dissolved in deionized water to prepare a precursor solution with a ferric chloride concentration of 0.1 mol / L. The carbonized intermediate is immersed in the precursor solution and transferred to a hydrothermal reactor, where it is reacted at 160°C for 10 h. After the reaction, the mixture is cooled, washed, and vacuum dried at 60°C for 9 h, allowing the iron-tellurium compound to grow in situ on the inner wall of the pores to form a heterojunction structure.
[0056] S6. Surface modification treatment: First, chemical vapor deposition is used to deposit a 3nm thick graphene conductive layer by introducing a mixed gas of methane and hydrogen at 900℃ for 15min; then oxygen plasma treatment is used for 40s with a radio frequency power of 120W and an oxygen flow rate of 40sccm to obtain a porous structure of supercapacitor composite electrode.
[0057] Comparative example: Raw material preparation: Select the same type of raw material as in Example 1: MXene. The concentration was 5 mg / mL; the nitrogen-doped carbon source was melamine, added at 200% of the MXene mass; the metal-organic framework precursor was ZIF-67, added at 150% of the MXene mass; no pore structure directing agent or surfactant was added; the transition metal salt was cobalt nitrate, the chalcogen source was thiourea, and the structure regulator was hexamethylenetetramine; the protective atmosphere was nitrogen, and the activating gas was carbon dioxide.
[0058] Preparation step S1, preparation of precursor solution: The dispersion, melamine, and ZIF-67 powder were mixed and stirred for 30 minutes. No pore structure guiding agent, crosslinking modifier, or surfactant was added, and the precursor mixed solution was directly prepared (with slight agglomeration).
[0059] S2. Non-directional molding: The precursor mixture solution is injected into the mold and frozen in a -80℃ freezer for 4 hours using a normal freezing method. There is no directional temperature gradient, and the ice crystals grow randomly.
[0060] S3, Conventional drying: The frozen sample was directly dried at -50℃ and 50Pa vacuum for 24 hours without using a gradient temperature program.
[0061] S4. Heat treatment carbonization activation: Same as in Example 1, staged heating carbonization and carbon dioxide activation are carried out to obtain carbonized intermediate.
[0062] S5. In-situ growth composite: Same as in Example 1, a heterojunction composite structure is prepared by hydrothermal reaction.
[0063] S6, No surface modification: The comparative electrode material is obtained directly without plasma treatment or chemical vapor deposition treatment.
[0064] Performance testing and comparison: Table 1: Details of Raw Material Ratios and Process Parameters for Examples and Comparative Examples project Example 1 Example 2 Example 3 Comparative Example MXene type and concentration Ti3C2Tx, 5 mg / mL Ti2CTx+V2CTx (1:1), 10mg / mL Nb2CTx+Mo2CTx (2:1), 3mg / mL Ti3C2Tx, 5 mg / mL Nitrogen-doped carbon source and amount added Melamine, MXene quality 200% Polydopamine, MXene quality 300% Chitosan, MXene 150% Melamine, MXene quality 200% Pore structure guiding agent and concentration Polyvinyl alcohol, 2wt% Polyethylene glycol, 5wt% Sodium carboxymethyl cellulose, 1 wt% none Surfactants and dosage Sodium dodecyl sulfate, 0.5% cetyltrimethylammonium bromide, 1% Tween 80, 0.3% none Freezing method and rate One-way freezing, 3mm / min One-way freezing, 5mm / min One-way freezing, 2mm / min Ordinary freezing, non-directional freeze drying method Gradient heating Gradient heating Gradient heating Conventional constant temperature drying Surface modification methods Chemical vapor deposition Oxygen + Nitrogen Plasma Chemical vapor deposition + plasma none Table 1 summarizes the differences between the examples and the comparative examples in terms of raw material composition and core processes. The examples all incorporated pore-directing agents, surfactants, and crosslinking modifiers, employed unidirectional freezing to construct directional channels, and used gradient-heat freeze-drying to ensure structural integrity, along with targeted surface modification. The comparative examples, lacking key functional components, used non-directional freezing and conventional drying, without any surface modification steps. These design differences precisely target the shortcomings of traditional processes, laying the foundation for the performance advantages of the materials in the examples.
[0065] Table 2: Comparison of Hole Structure Parameters between Examples and Comparative Examples Hole structure parameters Example 1 Example 2 Example 3 Comparative Example Orientation of the channel high high high Undirected Porosity high high high lower Micropore ratio Reasonable Reasonable Reasonable High Mesoporous ratio Moderate Moderate Moderate Low Large hole ratio Moderate Moderate Moderate messy Hole structure integrity whole whole whole Partial collapse Table 2 summarizes: The examples employ unidirectional freezing technology, resulting in high pore orientation. Furthermore, gradient temperature freeze-drying effectively prevents pore structure collapse, leading to high porosity and structural integrity. The hierarchical pore structure exhibits a reasonable ratio of micropores, mesopores, and macropores, effectively balancing ion storage and transport. In contrast, the comparative examples, lacking directional freezing and gradient drying, exhibit non-directional pores, lower porosity, and partial pore structure collapse. The proportion of micropores is too high, while the proportion of mesopores is insufficient, obstructing ion transport paths. This clearly demonstrates the superiority of the present invention's process in controlling pore structure.
[0066] Table 3: Comparison of Overall Performance between Examples and Comparative Examples Performance indicators Example 1 Example 2 Example 3 Comparative Example electrical conductivity Excellent Excellent Excellent Poor Specific capacitance high high high lower High-rate performance good good good Poor Cyclic stability excellent excellent excellent Poor Electrolyte wettability good good good Poor Structural stability powerful powerful powerful weak Table 3 summarizes: The embodiments significantly outperform the comparative examples in all performance indicators. The excellent conductivity of the embodiments is attributed to the conductive network constructed from MXene and a nitrogen-doped carbon source, as well as the surface conductive enhancement layer; the high specific capacitance and good high-rate performance stem from the synergistic effect of the reasonable hierarchical pore structure and heterojunction composite structure; the excellent cycle stability and structural stability are attributed to the buffer space provided by the directional channels and the tight interfacial bonding of the components; and the good electrolyte wettability comes from the hydrophilic functional groups introduced by surface modification. The comparative examples, due to their unreasonable pore structure and lack of surface modification, exhibited poor conductivity, capacitance, and stability, thus demonstrating the comprehensive advantages of the technical solution of this invention.
[0067] Results analysis: The test data above show that the porous structures of the supercapacitor composite electrodes prepared in Examples 1 to 3 of this invention are significantly superior to the comparative examples in terms of pore structure design, component composition, and performance. The examples successfully constructed a directional, hierarchical porous structure by adding a pore structure guiding agent, surfactant, and crosslinking modifier, combined with unidirectional freezing and gradient freeze-drying processes, thus solving the problems of non-directional pores and easy structural collapse in traditional materials. Through multi-component synergistic composite and in-situ growth technology, the interface bonding was optimized, improving conductivity and structural stability. Surface modification treatment improved electrolyte wettability, further optimizing capacitance performance. The comparative examples, lacking key components and core processes, exhibited significant shortcomings in pore structure, conductivity, and stability. This fully demonstrates that this invention, through raw material ratio optimization and process innovation, achieves a comprehensive improvement in the overall performance of supercapacitor composite electrode materials, meeting the application requirements of high-performance energy storage devices.
[0068] Reference Figure 2 The figure visually demonstrates the precise control effect of the process of this invention on the pore structure. The porosity and orientation of the embodiment are much higher than those of the comparative example, and the proportion of micropores is reasonable, which confirms the synergistic effect of unidirectional freezing, gradient drying and pore structure guiding agent, and successfully constructs an oriented hierarchical porous structure. In contrast, the comparative example lacks key processes and components, resulting in non-oriented pores, low porosity and an unbalanced proportion of micropores.
[0069] Reference Figure 3 The figure clearly illustrates the influence of freezing rate on channel orientation. Orientation initially increases and then decreases with increasing freezing rate, reaching its optimum at 5 mm / min. This indicates that a moderate freezing rate allows ice crystals to grow in a fully oriented manner along the temperature gradient; rates that are too fast or too slow will lead to disordered ice crystal growth, thus verifying the scientific validity of the freezing rate parameter control in this invention.
[0070] Reference Figure 4 The radar chart comprehensively demonstrates the effect of surface modification on the overall performance of the material. The combined modification (Example 2) scored highest across all indicators, with only chemical vapor deposition modification showing outstanding performance in conductivity, and only plasma modification demonstrating a significant advantage in electrolyte wettability. The unmodified sample exhibited poor performance in all aspects. This proves that the surface modification method employed in this invention can synergistically optimize the multi-dimensional properties of the material, and is a key technology for improving the overall performance of the electrode.
[0071] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.
Claims
1. A process for directional fabrication of porous structures for supercapacitor composite electrodes, characterized in that, Includes the following steps: S1. Preparation of precursor solution: Mix MXene dispersion, nitrogen-doped carbon source, metal-organic framework precursor and pore structure guiding agent in a preset ratio, and add crosslinking modifier and surfactant under stirring to obtain a uniform and stable precursor composite solution. S2. Directional ice template molding: The precursor composite solution is injected into the mold and directional solidification is carried out using unidirectional freezing technology, with the freezing rate controlled at 0.5-10 mm / min and the freezing temperature at -196℃ to -40℃. S3. Freeze-drying and demolding: Freeze-dry the directionally solidified sample at -80℃ to -40℃ and a vacuum of 1-50Pa for 12-72h, sublimate to remove the ice crystal template, and obtain the precursor aerogel skeleton with oriented channels. S4. Heat treatment carbonization and activation: The precursor aerogel skeleton is placed in a protective atmosphere and heated to 600-1000℃ at a heating rate of 1-10℃ / min for 1-6h. Then, activation gas is introduced and activated at 700-900℃ for 0.5-3h to obtain a carbonized intermediate with a hierarchical porous structure. S5. In-situ growth composite: The carbonized intermediate is immersed in a precursor solution containing transition metal salts and chalcogen source, and hydrothermal reaction is carried out at 120-220℃ for 4-24 hours to allow the transition metal chalcogen compound to grow in-situ on the inner wall of the directional channel to form a heterojunction composite structure. S6. Surface modification treatment: Plasma surface modification or chemical vapor deposition treatment is performed on the heterojunction composite structure to construct a conductive reinforcement layer and hydrophilic functional groups on the pore surface, thereby obtaining a porous structure of supercapacitor composite electrode.
2. The directional fabrication process of the porous structure of the supercapacitor composite electrode according to claim 1, characterized in that, In step S1, the concentration of the MXene dispersion is 0.5-20 mg / mL, and MXene is selected from... One or more of the following are selected: nitrogen-doped carbon source is selected from melamine, dicyandiamide, urea, polydopamine, polyaniline, chitosan, and the amount added is 50-500% of the mass of MXene; metal-organic framework precursor is selected from one or more of ZIF-8, ZIF-67, MIL-88, UiO-66, HKUST-1, and the amount added is 20-300% of the mass of MXene.
3. The directional fabrication process of the porous structure of the supercapacitor composite electrode according to claim 1, characterized in that, In step S1, the pore structure guiding agent is selected from one or more of polyvinyl alcohol, polyethylene glycol, polyethylene oxide, sodium carboxymethyl cellulose, and sodium alginate, with a concentration of 0.1-10 wt%; the crosslinking modifier is selected from one or more of glutaraldehyde, epichlorohydrin, citric acid, boric acid, and genipin, with a mass ratio of 0.01-0.5:1 to the pore structure guiding agent; the surfactant is selected from one or more of sodium dodecyl sulfate, hexadecyltrimethylammonium bromide, Triton X-100, and Tween 80, with an addition amount of 0.01-2% of the total mass of the precursor composite solution.
4. The directional fabrication process of the porous structure of the supercapacitor composite electrode according to claim 1, characterized in that, In step S2, the unidirectional freezing technology adopts a bottom freezing method: the precursor composite solution is injected into a cylindrical mold with a top opening. The bottom of the mold is a high thermal conductivity metal plate and the side walls are made of heat insulation material. The bottom of the mold is in contact with a cold source, which is selected from one of the following: liquid nitrogen cold bath, dry ice-ethanol cold bath, semiconductor refrigeration chip, and programmable temperature-controlled freezing stage. The temperature of the cold source is controlled from -196°C to -40°C by adjusting the contact area between the cold source and the mold or the power of the cold source.
5. The directional fabrication process of the porous structure of the supercapacitor composite electrode according to claim 1, characterized in that, In step S3, the freeze-drying process employs a gradient temperature program: the first stage is maintained at -80℃ to -60℃ and a vacuum of 1-10 Pa for 4-12 hours; the second stage involves heating at a rate of 0.5-2℃ / h to -40℃ to -30℃ and maintaining the temperature for 4-24 hours under a vacuum of 5-20 Pa; the third stage involves heating at a rate of 1-5℃ / h to 0-25℃ and maintaining the temperature for 4-24 hours under a vacuum of 10-50 Pa; ultimately, a directional porous aerogel framework with a porosity of 85-98% and a pore size of 5-200 μm is obtained.
6. The directional fabrication process of the porous structure of the supercapacitor composite electrode according to claim 1, characterized in that, In step S4, the protective atmosphere is selected from nitrogen, argon, or a mixture of nitrogen and hydrogen, with hydrogen comprising 3-10% of the mixture. The carbonization process employs a segmented heating program: pre-carbonization is performed by heating to 300-400℃ at a rate of 1-3℃ / min and holding for 0.5-2 hours, followed by complete carbonization by heating to 600-1000℃ at a rate of 2-5℃ / min and holding for 1-6 hours. The activation gas is selected from one or more of carbon dioxide, water vapor, and ammonia, with a flow rate of 50-500 mL / min. After carbonization and activation, the carbonization intermediate has a micropore diameter of 0.5-2 nm, a mesopore diameter of 2-50 nm, a macropore diameter of 50 nm-200 μm, and a specific surface area of 500-3000 m². 2 / g.
7. The directional fabrication process of the porous structure of the supercapacitor composite electrode according to claim 1, characterized in that, In step S5, the transition metal salt is selected from one or more of cobalt salt, nickel salt, iron salt, molybdenum salt, tungsten salt, and manganese salt, and its concentration in the precursor solution is 0.01-1 mol / L; the chalcogen source is selected from one or more of thiourea, thioacetamide, selenium powder, selenocysteine, tellurium powder, and sodium telluride, and its molar ratio with the transition metal salt is 1-10:1; the precursor solution also contains a structure regulator, which is selected from one or more of hexamethylenetetramine, urea, ammonium fluoride, and oxalic acid, and its concentration is 0.05-2 mol / L; after the hydrothermal reaction, the transition metal chalcogen compound is in the form of nanosheets, nanoflowers, or nanowires.
8. The directional fabrication process of the porous structure of the supercapacitor composite electrode according to claim 1, characterized in that, In step S6, the plasma surface modification treatment includes: oxygen plasma treatment for 10-300s, radio frequency power of 50-300W, and oxygen flow rate of 10-100sccm; or nitrogen plasma treatment for 10-300s, radio frequency power of 50-300W, and nitrogen flow rate of 10-100sccm; after treatment, the surface oxygen content is 5-20at%, and the nitrogen content is 2-15at.
9. The directional fabrication process of the porous structure of the supercapacitor composite electrode according to claim 1, characterized in that, In step S6, the chemical vapor deposition process includes: placing the heterojunction composite structure in a reaction chamber and introducing a mixture of carbon source gas and hydrogen gas; the carbon source gas is selected from one or more of methane, ethylene, acetylene, and benzene, with a flow rate of 5-100 sccm, and the hydrogen gas flow rate is 50-500 sccm; and depositing at 800-1100℃ for 5-60 min.
10. The directional fabrication process of the porous structure of the supercapacitor composite electrode according to claim 1, characterized in that, The performance parameters of the prepared porous structures are as follows: orientation degree of oriented channels 70-95%, channel diameter 5-100 μm, channel length 0.5-10 mm; specific surface area 800-2500 m² / g. 2 / g, pore volume 0.5-3.0cm 3 / g; In a three-electrode system and 6MKOH electrolyte, the specific capacitance is 300-800F / g at a current density of 1A / g, and the capacitance retention rate is 70-95% at a current density of 50A / g; After 10,000 cycles at a current density of 10A / g, the capacitance retention rate is greater than 90%.