A method of manufacturing a capacitor and a capacitor

Abstract

The application relates to the technical field of capacitor preparation, in particular to a capacitor preparation method and a capacitor. A core body is arranged in a packaging shell, and the core body is composed of a positive metal foil base material, a positive mesoporous metal oxide layer, a positive conductive polymer interface layer, a two-phase solid electrolyte layer, a negative conductive polymer interface layer, a negative mesoporous metal oxide layer and a negative metal foil base material. Through multistage surface modification and covalent bonding interface layer construction processes on the positive and negative metal foil base materials, the surface structure, chemical active sites, interface layer thickness and conductivity of the positive and negative electrodes are highly consistent, the interface contact performance and ion transmission efficiency of the positive and negative electrodes and the electrolyte are not different, the uneven charge distribution and local polarization problems caused by the asymmetric treatment of the positive and negative electrodes in the prior art are solved from the root, the capacitor charging and discharging process is more stable, the charging and discharging efficiency is improved, and the capacitor local overheating and performance attenuation caused by polarization are effectively avoided.

Description

Technical Field

[0001] This invention relates to the field of capacitor manufacturing technology, and more particularly to a method for manufacturing a capacitor and the capacitor itself. Background Technology

[0002] As an indispensable basic energy storage component in electronic circuits, the performance of capacitors directly determines the operational stability, response speed, and lifespan of electronic devices. With the rapid development of electronic technology, the performance requirements for capacitors in high-end electronics are constantly upgrading. They not only require high energy density and high power density, but also need to meet conditions such as wide operating temperature range, long cycle life, and no safety hazards.

[0003] Existing capacitors are mostly manufactured using physical roughening treatments to roughen the surfaces of the positive and negative electrodes. This results in significant differences in the interfacial contact performance and ion transport efficiency between the positive and negative electrodes and the electrolyte. During the charging and discharging process, the charge distribution is uneven, and local polarization is prone to occur, which greatly reduces the charging and discharging efficiency and cycle stability. Therefore, it is necessary to design a new type of capacitor. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a method for manufacturing a capacitor and a capacitor.

[0005] The technical solution adopted in this invention is as follows: A capacitor includes a package shell, inside which a core is disposed. Multiple cores are disposed, and each core is composed of a positive electrode metal foil substrate, a positive electrode mesoporous metal oxide layer, a positive electrode conductive polymer interface layer, a dual-phase solid electrolyte layer, a negative electrode conductive polymer interface layer, a negative electrode mesoporous metal oxide layer, and a negative electrode metal foil substrate. The positive electrode metal foil substrate, positive electrode mesoporous metal oxide layer, positive electrode conductive polymer interface layer, dual-phase solid electrolyte layer, negative electrode conductive polymer interface layer, and negative electrode mesoporous metal oxide layer are all present in the package shell. The metal oxide layer and the negative electrode metal foil substrate are distributed sequentially from bottom to top; a positive electrode conductive plate is fixedly connected to the end of the positive electrode metal foil substrate, and a positive electrode metal tab is fixedly connected to the end of the positive electrode conductive plate away from the positive electrode metal foil substrate. The positive electrode metal tab penetrates through the upper end of the packaging shell and is fixedly connected to the packaging shell; a negative electrode conductive plate is fixedly connected to the end of the negative electrode metal foil substrate, and a negative electrode metal tab is fixedly connected to the end of the negative electrode conductive plate away from the negative electrode metal foil substrate. The negative electrode metal tab penetrates through the upper end of the packaging shell and is fixedly connected to the packaging shell.

[0006] A method for manufacturing a capacitor, comprising the following steps: S1. Multi-level surface modification of positive and negative electrode substrates: Metal foils were selected as positive and negative electrode metal foil substrates, respectively. Chemical etching, ultrasonic cleaning and drying, plasma etching and in-situ growth of mesoporous metal oxide layers were carried out in sequence to form a three-level rough structure of micron, nano and mesoporous with high density of hydroxyl active sites and porosity of 40%-60% on the surface of both positive and negative electrode substrates. S2. Construction of covalently bonded conductive polymer interface layer: Utilizing the hydroxyl active sites of the mesoporous metal oxide layer on the surface of the positive and negative electrode metal foil substrates, the conductive polymer monomers undergo esterification or amidation reactions with hydroxyl groups through electrochemical polymerization at 25℃-40℃, thereby forming a covalently bonded conductive polymer interface layer in situ on the surface of the positive and negative electrode metal foil substrates and in the mesoporous channels. S3. Preparation of biphase solid electrolyte precursor: Inorganic ionic conductor, organic polymer monomer, ionic liquid plasticizer, interfacial ionic anchoring agent and photothermal composite initiator are mixed in mass ratio, added to organic solvent and dispersed by gradient stirring and ultrasonication to obtain a homogeneous biphase solid electrolyte precursor solution without agglomeration. S4. In-situ directional polymerization filling: In a dust-free environment with ambient temperature and humidity ≤60%, a biphase solid electrolyte precursor solution is applied to the surface of the conductive polymer interface layer of the positive electrode metal foil substrate to form a biphase solid electrolyte layer. The conductive polymer interface layer of the negative electrode metal foil substrate is then attached to it, and a slight pressure is applied. The precursor is directionally penetrated along the mesoporous channels by utilizing the capillary action of the mesopores. In-situ polymerization is initiated by photothermal synergy to solidify the precursor without gaps, forming a sandwich composite preform of positive electrode, electrolyte, and negative electrode. S5. Segmented vacuum heat treatment curing: The sandwich composite preform is placed in a vacuum heat treatment furnace and subjected to gradient segmented heating heat treatment under a vacuum of 0.05-0.1MPa to complete the thorough curing of the solid electrolyte and strengthen the chemical bonding between the electrode and the interface layer, and between the interface layer and the electrolyte. After heat treatment, it is slowly cooled to room temperature at a rate of ≤5℃ / min. S6. Core Forming and Packaging: The heat-treated composite blank is cut into blank units with high precision. According to the capacity requirements, the capacitor core is formed by stacking. The positive electrode of the core is welded to the positive electrode metal ear through the positive electrode conductive plate, and the negative electrode of the core is welded to the negative electrode metal ear through the negative electrode conductive plate. Finally, after airtightness testing, it is sealed by plastic encapsulation to obtain a solid-state capacitor.

[0007] As a further description of the above technical solution: In step S1, the metal foil is one of aluminum foil, copper foil, titanium foil, and nickel foil, with a thickness of 1050 μm; the mesoporous metal oxide layer is one of aluminum oxide, titanium dioxide, niobium pentoxide, and tin dioxide, and is grown in situ using a sol-gel method combined with hydrothermal synthesis, with a mesoporous pore size of 20-100 nm and a layer thickness of 50-200 nm; the hydrothermal synthesis process conditions are: using deionized water and anhydrous ethanol as a mixed solvent, a reaction temperature of 100℃-160℃, a reaction pressure of 0.1-0.3 MPa, and a constant temperature and pressure reaction for 4-8 h.

[0008] As a further description of the above technical solution: In step S1, chemical etching uses a 5%-15% hydrochloric acid solution and is performed at room temperature for 5-15 minutes. After etching, the solution is ultrasonically cleaned with 200-400W deionized water for 3-8 minutes, and then dried in a vacuum drying oven at 60℃-80℃ for 2-4 hours. In plasma etching, a mixed gas with an argon-oxygen volume ratio of 8-9:2-1 is used, with an etching chamber pressure of 0.1-0.5Pa, an etching power of 80-120W, and a processing time of 3-8 minutes.

[0009] As a further description of the above technical solution: In step S2, the conductive polymer monomer is either pyrrole or aniline, and the overall thickness of the conductive polymer interface layer is 80-200 nm. The constant current density of the electrochemical polymerization is 1-3 mA / cm², and the polymerization time is 10-30 min. The electrochemical polymerization solution consists of the conductive polymer monomer and an organic solution supporting the electrolyte, and the mass ratio of the two is 1:1-1.5. The supporting electrolyte is either lithium perchlorate or tetraethylammonium chloride.

[0010] As a further description of the above technical solution: In step S3, the components are distributed as follows by mass percentage: 15%-30% inorganic ionic conductor, 40%-65% organic polymer monomer, 10%-25% ionic liquid plasticizer, 0.5%-2% interfacial ionic anchoring agent, and 1%-3% photothermal composite initiator; the inorganic ionic conductor is LiAlO2 or Na3Zr2Si2PO4. 12 Li7La3Zr2O 12The organic polymer monomer is one of polyethylene glycol diacrylate and epoxy resin; the interfacial ionic anchoring agent is one of γ-aminopropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane; the ionic liquid plasticizer is one of 1-ethyl-3-methylimidazolium tetrafluoroborate, N-butylpyridine hexafluorophosphate, and 1-butyl-3-methylpyrrolidone bis(trifluoromethanesulfonyl)imide; the photothermal composite initiator is a compound system of photoinitiator and thermal initiator with a mass ratio of 2:1, wherein the photoinitiator is one of 2-hydroxy-2-methyl-1-phenyl-1-propanone and 1-hydroxycyclohexylphenyl ketone, and the thermal initiator is one of AIBN and BPO.

[0011] As a further description of the above technical solution: In step S3, the organic solvent is one of ethyl acetate, anhydrous ethanol, and acetone; the gradient stirring is to first stir at 200-300 r / min for 15-20 min, and then stir at 400-500 r / min for 30-40 min; the ultrasonic dispersion power is 200-400 W, the dispersion time is 20-30 min, and the water bath temperature is controlled at 25℃-30℃ during the dispersion process to avoid the system temperature rising.

[0012] As a further description of the above technical solution: In step S4, the biphase solid electrolyte precursor solution is applied by dip coating, with a dip coating pull-up rate of 5-10 mm / s; the pressure applied during bonding is 0.1-0.3 MPa; the photothermal synergistic initiation conditions are: first, thermal initiation prepolymerization at 40℃-60℃, with the prepolymerization degree controlled at 30%-40%, followed by deep polymerization irradiation with 254-365nm ultraviolet light at a light intensity of 50-100mW / cm² for 30-90s.

[0013] As a further description of the above technical solution: The specific process of segmented vacuum heat treatment in step S5 is as follows: In the first stage, the temperature is raised to 70℃-90℃ at a heating rate of 2-5℃ / min and held for 1-2 hours to remove residual solvent and microbubbles; in the second stage, the temperature is raised to 140℃-160℃ at a heating rate of 1-3℃ / min and held for 3-5 hours to achieve complete solidification of the electrolyte and strengthen the interfacial chemical bonding; during the cooling process, the vacuum degree in the furnace is maintained until the temperature drops below 80℃, and then the pressure is naturally released to atmospheric pressure.

[0014] The present invention has the following beneficial effects: 1. This invention employs a multi-level surface modification and covalent bonding interface layer construction process on the positive and negative electrode metal foil substrates to achieve a high degree of consistency in the surface structure, chemical active sites, interface layer thickness, and conductivity of the positive and negative electrodes. This ensures no difference in the interfacial contact performance and ion transport efficiency between the positive and negative electrodes and the electrolyte. It fundamentally solves the problem of uneven charge distribution and localized polarization caused by asymmetric positive and negative electrode processing in existing technologies, resulting in a more stable capacitor charging and discharging process, improved charging and discharging efficiency, and effective prevention of localized overheating and performance degradation caused by polarization.

[0015] 2. This invention improves the specific surface area of ​​the electrodes by constructing a three-level rough structure of micron, nano, and mesoporous layers on the positive and negative electrode surfaces, providing sufficient physical contact area for electrolyte filling. Simultaneously, through in-situ growth of the mesoporous metal oxide layer and covalent bonding of the conductive polymer interface layer, chemical bonding of the electrode, interface layer, and electrolyte is achieved. The interface layer fills the mesoporous channels to form an anchoring structure. Combined with the capillary action of the mesoporous layers and the void-free filling through photothermal synergistic polymerization, a dual-bonded structure of chemical covalent bonding and physical void-free adhesion is formed. This completely eliminates the microcracks caused by interfacial gaps, filling voids, and temperature alternation, solving the core problem of poor interfacial contact in existing solid-state capacitors from both physical and chemical dimensions. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the internal structure of the capacitor of the present invention; Figure 2 This is a schematic diagram of the structure of the capacitor core of the present invention; Figure 3 This is a flowchart of the method of the present invention.

[0017] Legend: 1. Core; 101. Positive electrode metal foil substrate; 102. Positive electrode mesoporous metal oxide layer; 103. Positive electrode conductive polymer interface layer; 104. Two-phase solid electrolyte layer; 105. Negative electrode conductive polymer interface layer; 106. Negative electrode mesoporous metal oxide layer; 107. Negative electrode metal foil substrate; 2. Positive electrode conductive plate; 3. Negative electrode conductive plate; 4. Positive electrode metal tab; 5. Negative electrode metal tab; 6. Encapsulation shell. Detailed Implementation

[0018] Reference Figure 1-3The present invention provides a capacitor comprising a casing 6, inside which a core 1 is disposed. Multiple cores 1 are disposed, each core 1 being composed of a positive electrode metal foil substrate 101, a positive electrode mesoporous metal oxide layer 102, a positive electrode conductive polymer interface layer 103, a dual-phase solid electrolyte layer 104, a negative electrode conductive polymer interface layer 105, a negative electrode mesoporous metal oxide layer 106, and a negative electrode metal foil substrate 107. The positive electrode metal foil substrate 101, positive electrode mesoporous metal oxide layer 102, positive electrode conductive polymer interface layer 103, dual-phase solid electrolyte layer 104, negative electrode conductive polymer interface layer 105, and negative electrode... Mesoporous metal oxide layer 106 and negative electrode metal foil substrate 107 are distributed sequentially from bottom to top; a positive electrode conductive plate 2 is fixedly connected to the end of the positive electrode metal foil substrate 101, and a positive electrode metal ear 4 is fixedly connected to the end of the positive electrode conductive plate 2 away from the positive electrode metal foil substrate 101. The positive electrode metal ear 4 penetrates through the upper end of the encapsulation shell 6 and is fixedly connected to the encapsulation shell 6; a negative electrode conductive plate 3 is fixedly connected to the end of the negative electrode metal foil substrate 107, and a negative electrode metal ear 5 is fixedly connected to the end of the negative electrode conductive plate 3 away from the negative electrode metal foil substrate 107. The negative electrode metal ear 5 penetrates through the upper end of the encapsulation shell 6 and is fixedly connected to the encapsulation shell 6.

[0019] A method for manufacturing a capacitor, comprising the following steps: S1. Multi-level surface modification of positive and negative electrode substrates: The core of this step is to perform a fully synchronized three-level modification process on the positive and negative electrode metal foil substrates, ensuring a high degree of consistency in their surface structure and chemical active sites. This lays the foundation for subsequent interface layer construction and electrolyte filling. Ultimately, a three-level rough structure of micron, nano, and mesoporous layers is formed on the surface of the positive and negative electrode substrates, with a high density of hydroxyl active sites. The specific surface area of ​​the electrodes is increased compared to the original foil material. This step is specifically divided into four sub-steps: Chemical etching: Select metal foils of the same or different specifications (the metal foils are one of aluminum foil, copper foil, titanium foil, and nickel foil, with a thickness of 1050μm) as positive electrode metal foil substrate 101 and negative electrode metal foil substrate 107, respectively, and immerse them in a 5%-15% hydrochloric acid solution for etching at room temperature for 5-15 minutes; by utilizing the corrosion reaction between the acid and the metal foil, a uniform micron-level rough undulation structure is formed on the surface of the foil, which initially increases the specific surface area of ​​the electrode and provides a foundation for subsequent nanoscale modification and mesoporous growth.

[0020] Ultrasonic cleaning and drying: After etching, remove the foil and ultrasonically clean it with 200-400W deionized water for 3-8 minutes to thoroughly remove residual acid, corrosion products and impurities from the surface of the foil. After cleaning, place the foil in a vacuum drying oven at 60℃-80℃ for 2-4 hours to dry it, so as to avoid residual moisture on the surface from affecting subsequent processes.

[0021] Plasma etching: The dried positive and negative electrode metal foils are placed in a plasma etching equipment, and a mixed gas with an argon-oxygen volume ratio of 8-9:2-1 is introduced. The etching chamber pressure is adjusted to 0.1-0.5 Pa, and etching is performed at a power of 80-120 W for 3-8 minutes. On the basis of the micron-level rough structure, plasma etching further forms nano-level micropores, so that the electrode surface forms a micron- and nano-level rough structure. At the same time, through the activation effect of plasma, a large number of chemically active sites such as hydroxyl (-OH) and carboxyl (-COOH) groups are introduced on the electrode surface.

[0022] In-situ growth of mesoporous metal oxide layers: A sol-gel method combined with hydrothermal synthesis was used to grow three-dimensionally interconnected mesoporous metal oxide layers in situ on the surfaces of positive and negative electrode metal foils. First, the foil was immersed in a metal oxide sol and coated at a pulling rate of 5-10 mm / s. After removal, it was allowed to stand at room temperature for 10-20 minutes, and then dried at 80℃-100℃ for 1-2 hours to form a wet gel layer. Subsequently, the foil was placed in a hydrothermal reactor using deionized water and anhydrous ethanol as a mixed solvent. The wet gel layer is crystallized and formed into a mesoporous metal oxide layer by reacting at a constant temperature and pressure of 100℃-160℃ and 0.1-0.3MPa for 4-8 hours. The mesoporous pore size of this layer is 20-100nm, the porosity is 40%-60%, and the thickness is 50-200nm. This not only gives the electrode a three-level rough structure of micron, nano and mesoporous, but also provides active sites for the covalent bonding of the subsequent interface layer with its high-density hydroxyl groups on the surface. The three-dimensional interconnected mesoporous channels provide guidance for the directional filling of the electrolyte.

[0023] S2. Construction of covalently bonded conductive polymer interface layer: The core of this step is to achieve chemical covalent bonding between the conductive polymer interface layer and the positive and negative electrode substrates, while simultaneously filling the mesoporous channels with the interface layer to form an anchoring structure. This abandons the traditional physical adhesion method, significantly improving the interfacial bonding strength, and ensuring that the thickness, filling rate, and conductivity of the positive and negative electrode interface layers are highly consistent. The specific process is as follows: Preparation of reaction solution: Prepare an electrochemical polymerization solution, which consists of an organic solution of a conductive polymer monomer (the conductive polymer monomer is one of pyrrole and aniline) and a supporting electrolyte (the supporting electrolyte is one of lithium perchlorate and tetraethylammonium chloride), and the mass ratio of the two is 1:1-1.5.

[0024] In-situ covalent polymerization: The positive and negative electrode metal foil substrates that have undergone multi-stage modification are immersed in the reaction solution, and the reaction is initiated by electrochemical polymerization under constant temperature conditions of 25℃-40℃. The electrochemical polymerization adopts a constant current mode with a current density of 1-3mA / cm² and a polymerization time of 10-30min. During the polymerization process, the amino, hydroxyl or carboxyl groups of the conductive polymer monomer undergo esterification or amidation reactions with the hydroxyl groups of the mesoporous metal oxide layer on the electrode surface to form stable ester bonds or amide bonds, so that the conductive polymer grows in situ on the electrode surface and in the mesoporous channels.

[0025] Post-treatment cleaning and drying: After polymerization, the electrodes are removed and ultrasonically cleaned with deionized water for 3-5 minutes to remove residual reaction solution, unreacted monomers and byproducts on the surface; after cleaning, the electrodes are placed in a vacuum drying oven at 60℃-80℃ and dried for 2-3 hours to obtain positive and negative electrodes with a covalently bonded conductive polymer interface layer on the surface; the overall thickness of the conductive polymer interface layer is 80-200nm, forming a continuous surface layer and a pore-filling anchoring structure, achieving gapless covalent bonding with the electrode substrate.

[0026] S3. Preparation of the two-phase solid electrolyte precursor: The core of this step is to design an inorganic-organic dual-phase solid electrolyte system. Through precise formulation and homogenization of each component, the electrolyte's ion conductivity, flexibility, thermal stability, and interfacial adhesion are synergistically improved. Simultaneously, an interfacial ion anchoring agent is introduced to construct a continuous channel for subsequent interfacial ion transport. The specific process is as follows: Raw material weighing: Weigh out the following components by mass ratio: inorganic ionic conductor (15%-30%), organic polymer monomer (40%-65%), ionic liquid plasticizer (10%-25%), interfacial ionic anchoring agent (0.5%-2%), and photothermal composite initiator (1%-3%). All components are selected from conventional raw materials produced in industrial mass production, without customization, and without toxic or harmful components.

[0027] Gradient stirring and mixing: Add the above raw materials to a single or mixed organic solvent such as ethyl acetate, anhydrous ethanol or acetone. First, stir at a low speed of 200-300 r / min for 15-20 min to initially disperse the raw materials; then stir at a high speed of 400-500 r / min for 30-40 min to fully mix the raw materials and organic solvent to form a preliminary homogeneous system.

[0028] Low-temperature ultrasonic dispersion: The preliminarily homogeneous system is placed in a water bath at 25℃-30℃ and ultrasonically dispersed for 20-30 minutes using a power of 200-400W. The water bath temperature control avoids premature reaction of the raw materials caused by the temperature rise of the system during ultrasonication. Ultrasonic dispersion can completely eliminate the agglomeration of the raw materials and obtain a homogeneous, agglomerated, and highly fluid biphase solid electrolyte precursor solution. This solution can freely permeate along the mesoporous channels, laying the foundation for subsequent directional void-free filling.

[0029] The synergistic effects of each component are clear: ① The inorganic ionic conductors are LiAlO2 and Na3Zr2Si2PO4. 12 Li7La3Zr2O 12 ① One of Li3PO4 is used to improve the ion conduction efficiency and thermal stability of the electrolyte, providing the main channel for ion transport; ② One of the organic polymer monomers, polyethylene glycol diacrylate and epoxy resin, forms the organic framework of the electrolyte after polymerization, improving the flexibility of the electrolyte and its adhesion to the electrode interface, and alleviating the problem of mismatch in thermal expansion coefficients; ③ One of the ionic liquid plasticizers, 1-ethyl-3-methylimidazolium tetrafluoroborate, N-butylpyridine hexafluorophosphate, and 1-butyl-3-methylpyrrolidone bis(trifluoromethanesulfonyl)imide, is used to lower the glass transition temperature of the electrolyte, optimize the ion conduction performance of the electrolyte, and improve... Wide operating temperature range; ④ The interface ion anchoring agent is one of γ-aminopropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane, which forms ion bonds between the electrolyte and conductive polymer interface layer, constructs a continuous ion transport channel, and reduces the ion cross-interface transport barrier; ⑤ The photothermal composite initiator is a compound system of photoinitiator and thermal initiator with a mass ratio of 2:1. The photoinitiator is one of 2-hydroxy-2-methyl-1-phenyl-1-propanone and 1-hydroxycyclohexylphenyl ketone, and the thermal initiator is one of AIBN and BPO; it provides reaction kinetics for subsequent photothermal synergistic polymerization and realizes precise control of the polymerization process.

[0030] S4, In-situ Oriented Polymerization Filling: The core of this step is to achieve directional, void-free filling of the dual-phase solid electrolyte precursor in the mesoporous structures of the positive and negative electrodes. Through precise control of mesoporous capillary action and photothermal synergistic polymerization, the generation of bubbles and voids is avoided, ultimately forming a sandwich-type integrated composite preform consisting of the positive electrode, interface layer, electrolyte, interface layer, and negative electrode. Furthermore, the bonding between the positive and negative electrodes and the electrolyte is highly symmetrical. The specific process is as follows: Precursor application and bonding with the preform: In a dust-free environment with ambient temperature and humidity ≤60%, the biphase solid electrolyte precursor solution is uniformly applied to the surface of the conductive polymer interface layer of the positive electrode by dip coating to form a biphase solid electrolyte layer 104. The dip coating pull-up rate is 510 mm / s. Then, the conductive polymer interface layer of the negative electrode is tightly bonded to the precursor solution, and a slight pressing force of 0.1-0.3 MPa is applied to make the precursor solution uniformly distributed between the positive and negative electrodes.

[0031] Mesoporous capillary permeation: After bonding, let stand for 1-2 minutes. Utilize the capillary effect of the mesoporous structure on the surface of the positive and negative electrodes to allow the precursor solution to permeate directionally along the mesoporous channels until it is completely filled to the bottom of the channels, thus achieving the initial spreading of the precursor within the mesoporous structure.

[0032] Photothermal synergistic in-situ polymerization: The laminated preform is placed in a heating-ultraviolet light composite reaction device. It is first heated to 40℃-60℃ for thermal initiation prepolymerization, and the degree of prepolymerization is controlled at 30%-40%. Prepolymerization can initially solidify the precursor and avoid solution loss and bubble generation during subsequent photoinitiation. Then, ultraviolet light of 254-365nm is used to irradiate for 30-90s at a light intensity of 50-100mW / cm² to carry out photoinitiation deep polymerization, so that the precursor is completely solidified in the mesoporous channels and between the positive and negative electrodes, forming a void-free and bubble-free sandwich composite preform of positive electrode, electrolyte and negative electrode.

[0033] S5. Segmented vacuum heat treatment curing: The core of this step is to achieve complete solidification of the solid electrolyte, while removing residual organic solvents and microbubbles generated during polymerization. This strengthens the chemical bonds between the electrode and the interface layer, and between the interface layer and the electrolyte, improving the structural stability and reliability of the capacitor. Furthermore, slow cooling avoids internal stress caused by sudden temperature changes. The specific process is as follows: Loading and vacuuming: Place the sandwich composite billet flat into the vacuum heat treatment furnace, close the furnace door, and vacuum it to achieve a vacuum level of 0.05-0.1 MPa, and maintain the vacuum level stable.

[0034] Gradient segmented heating heat treatment: ① Pre-curing stage: slowly raise the temperature to 70℃-90℃ at a heating rate of 2-5℃ / min and hold for 1-2 hours; in this stage, low-temperature vacuum heating is used to slowly remove residual organic solvents and microbubbles generated by polymerization reaction in the electrolyte, avoiding the formation of voids at the interface, and achieving preliminary curing of the electrolyte; ② Complete curing stage: slowly raise the temperature to 140℃-160℃ at a heating rate of 1-3℃ / min and hold for 3-5 hours; in this stage, the solid electrolyte is completely cured, forming a dense biphase solid electrolyte layer 104, while promoting further stabilization and strengthening of chemical bonds between the electrode and the interface layer, and between the interface layer and the electrolyte, significantly improving the interfacial bonding strength.

[0035] Slow cooling: After heat treatment, turn off the heating device and allow the furnace temperature to cool slowly at a rate of ≤5℃ / min. During the cooling process, maintain a vacuum of 0.05-0.1MPa in the furnace until the temperature drops below 80℃, then slowly release the pressure to atmospheric pressure, and finally take out the solidified composite preform. Slow cooling and vacuum pressure holding can effectively avoid internal stress caused by sudden temperature changes and pressure changes, and prevent structural defects such as electrolyte cracking and interface delamination.

[0036] S6. Core molding and packaging: This step is the final stage of industrial mass production. Based on the capacitor's capacitance requirements, application scenarios, and size requirements, the capacitor core 1 is formed by cutting and stacking. After electrode tab welding and airtightness testing, it is sealed and packaged to obtain the finished solid-state capacitor. The specific process is as follows: High-precision cutting: The cured composite preform is placed in a high-precision cutting device and cut into preform units with uniform specifications according to the preset capacitor size and capacity; the cutting accuracy is controlled within ±0.05mm to avoid performance degradation caused by edge damage of the preform units.

[0037] Core forming: Select the lamination method according to the capacity requirements to form the capacitor core 1; the lamination method is suitable for medium and high capacity, thin capacitors, by alternately stacking multiple blank units, and aligning the positive and negative leads respectively.

[0038] Electrode welding: The positive electrode of the capacitor core 1 is welded to the positive electrode metal tab 4 through the positive electrode conductive plate 2, and the negative electrode is welded to the negative electrode metal tab 5 through the negative electrode conductive plate 3. The electrode material is matched with the electrode substrate. Aluminum foil electrodes are equipped with aluminum electrode tabs, and copper foil, titanium foil, and nickel foil electrodes are equipped with copper electrode tabs. The welding method is ultrasonic welding with a welding power of 1000-2000W and a welding time of 0.5-1s to ensure that the electrode tab and the core 1 are firmly connected and have low contact resistance.

[0039] Sealing and Testing: The capacitor is sealed using plastic encapsulation, which is suitable for common applications such as consumer electronics and communication equipment. After encapsulation, the capacitor undergoes airtightness testing, electrical performance testing, and high and low temperature performance testing. Once the tests are passed, it becomes a finished solid-state capacitor.

[0040] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A capacitor, comprising a package housing (6), characterized in that: The encapsulation shell (6) contains a core (1), and multiple cores (1) are provided. Each core (1) is composed of a positive electrode metal foil substrate (101), a positive electrode mesoporous metal oxide layer (102), a positive electrode conductive polymer interface layer (103), a dual-phase solid electrolyte layer (104), a negative electrode conductive polymer interface layer (105), a negative electrode mesoporous metal oxide layer (106), and a negative electrode metal foil substrate (107). The positive electrode metal foil substrate (101) and the negative electrode metal foil substrate (107) are distributed sequentially from bottom to top; the positive electrode metal foil substrate (101) is fixedly connected to a positive electrode conductive plate (2) at one end, and a positive electrode metal ear (4) is fixedly connected to one end of the positive electrode conductive plate (2) away from the positive electrode metal foil substrate (101). The positive electrode metal ear (4) penetrates the upper end of the encapsulation shell (6) and is fixedly connected to the encapsulation shell (6); the negative electrode metal foil substrate (107) is fixedly connected to a negative electrode conductive plate (3), and a negative electrode metal ear (5) is fixedly connected to one end of the negative electrode conductive plate (3) away from the negative electrode metal foil substrate (107). The negative electrode metal ear (5) penetrates the upper end of the encapsulation shell (6) and is fixedly connected to the encapsulation shell (6).

2. A method for manufacturing a capacitor, used to manufacture the capacitor according to claim 1, characterized in that, Includes the following steps: S1. Multi-level surface modification of positive and negative electrode substrates: Metal foils were selected as positive electrode metal foil substrates (101) and negative electrode metal foil substrates (107), respectively. Chemical etching, ultrasonic cleaning and drying, plasma etching and in-situ growth of mesoporous metal oxide layers were carried out in sequence to form a three-level rough structure of micron, nano and mesoporous with high density hydroxyl active sites and porosity of 40%-60% on the surface of both positive and negative electrode substrates. S2. Construction of covalently bonded conductive polymer interface layer: Utilizing the hydroxyl active sites of the mesoporous metal oxide layer on the surface of the positive and negative electrode metal foil substrates, the conductive polymer monomers undergo esterification or amidation reactions with hydroxyl groups through electrochemical polymerization at 25℃-40℃, thereby forming a covalently bonded conductive polymer interface layer in situ on the surface of the positive and negative electrode metal foil substrates and in the mesoporous channels. S3. Preparation of biphase solid electrolyte precursor: Inorganic ionic conductor, organic polymer monomer, ionic liquid plasticizer, interfacial ionic anchoring agent and photothermal composite initiator are mixed in mass ratio, added to organic solvent and dispersed by gradient stirring and ultrasonication to obtain a homogeneous biphase solid electrolyte precursor solution without agglomeration. S4. In-situ directional polymerization filling: In a dust-free environment with ambient temperature and humidity ≤60%, a biphase solid electrolyte precursor solution is applied to the surface of the conductive polymer interface layer of the positive electrode metal foil substrate (101) to form a biphase solid electrolyte layer (104), and the conductive polymer interface layer of the negative electrode metal foil substrate (107) is attached to it. A slight pressure is applied, and the precursor is directionally penetrated along the mesoporous channels by utilizing the mesoporous capillary action. In-situ polymerization is initiated by photothermal synergy to solidify the precursor without gaps, forming a sandwich composite preform of positive electrode, electrolyte and negative electrode. S5. Segmented vacuum heat treatment curing: The sandwich composite preform is placed in a vacuum heat treatment furnace and subjected to gradient segmented heating heat treatment under a vacuum of 0.05-0.1MPa to complete the thorough curing of the solid electrolyte and strengthen the chemical bonding between the electrode and the interface layer, and between the interface layer and the electrolyte. After heat treatment, it is slowly cooled to room temperature at a rate of ≤5℃ / min. S6. Core forming and packaging: The heat-treated composite blank is cut into blank units with high precision. According to the capacity requirements, the capacitor core (1) is formed by stacking. The positive electrode of the core (1) is welded to the positive electrode metal ear (4) through the positive electrode conductive plate (2). The negative electrode of the core (1) is welded to the negative electrode metal ear (5) through the negative electrode conductive plate (3). Finally, after the air tightness test, the solid capacitor is sealed by plastic encapsulation to obtain the solid capacitor.

3. The method for manufacturing a capacitor according to claim 2, characterized in that: In step S1, the metal foil is one of aluminum foil, copper foil, titanium foil, and nickel foil, with a thickness of 1050 μm; the mesoporous metal oxide layer is one of aluminum oxide, titanium dioxide, niobium pentoxide, and tin dioxide, and is grown in situ using a sol-gel method combined with hydrothermal synthesis, with a mesoporous pore size of 20-100 nm and a layer thickness of 50-200 nm; the hydrothermal synthesis process conditions are: using deionized water and anhydrous ethanol as a mixed solvent, a reaction temperature of 100℃-160℃, a reaction pressure of 0.1-0.3 MPa, and a constant temperature and pressure reaction for 4-8 h.

4. The method for manufacturing a capacitor according to claim 2, characterized in that: In step S1, chemical etching uses a 5%-15% hydrochloric acid solution and is performed at room temperature for 5-15 minutes. After etching, the solution is ultrasonically cleaned with 200-400W deionized water for 3-8 minutes, and then dried in a vacuum drying oven at 60℃-80℃ for 2-4 hours. In plasma etching, a mixed gas with an argon-oxygen volume ratio of 8-9:2-1 is used, with an etching chamber pressure of 0.1-0.5Pa, an etching power of 80-120W, and a processing time of 3-8 minutes.

5. The method for manufacturing a capacitor according to claim 2, characterized in that: In step S2, the conductive polymer monomer is either pyrrole or aniline, and the overall thickness of the conductive polymer interface layer is 80-200 nm. The constant current density of the electrochemical polymerization is 1-3 mA / cm², and the polymerization time is 10-30 min. The electrochemical polymerization solution consists of the conductive polymer monomer and an organic solution supporting the electrolyte, and the mass ratio of the two is 1:1-1.

5. The supporting electrolyte is either lithium perchlorate or tetraethylammonium chloride.

6. The method for manufacturing a capacitor according to claim 2, characterized in that: In step S3, the components are distributed as follows by mass percentage: 15%-30% inorganic ionic conductor, 40%-65% organic polymer monomer, 10%-25% ionic liquid plasticizer, 0.5%-2% interfacial ionic anchoring agent, and 1%-3% photothermal composite initiator; the inorganic ionic conductor is LiAlO2 or Na3Zr2Si2PO4. 12 Li7La3Zr2O 12 The organic polymer monomer is one of polyethylene glycol diacrylate and epoxy resin; the interfacial ionic anchoring agent is one of γ-aminopropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane; the ionic liquid plasticizer is one of 1-ethyl-3-methylimidazolium tetrafluoroborate, N-butylpyridine hexafluorophosphate, and 1-butyl-3-methylpyrrolidone bis(trifluoromethanesulfonyl)imide; the photothermal composite initiator is a compound system of photoinitiator and thermal initiator with a mass ratio of 2:1, wherein the photoinitiator is one of 2-hydroxy-2-methyl-1-phenyl-1-propanone and 1-hydroxycyclohexylphenyl ketone, and the thermal initiator is one of AIBN and BPO.

7. The method for manufacturing a capacitor according to claim 2, characterized in that: In step S3, the organic solvent is one of ethyl acetate, anhydrous ethanol, and acetone; the gradient stirring is to first stir at 200-300 r / min for 15-20 min, and then stir at 400-500 r / min for 30-40 min; the ultrasonic dispersion power is 200-400 W, the dispersion time is 20-30 min, and the water bath temperature is controlled at 25℃-30℃ during the dispersion process to avoid the system temperature rising.

8. The method for manufacturing a capacitor according to claim 2, characterized in that: In step S4, the biphase solid electrolyte precursor solution is applied by dip coating, with a dip coating pull-up rate of 5-10 mm / s; the pressure applied during bonding is 0.1-0.3 MPa; the photothermal synergistic initiation conditions are: first, thermal initiation prepolymerization at 40℃-60℃, with the prepolymerization degree controlled at 30%-40%, followed by deep polymerization irradiation with 254-365nm ultraviolet light at a light intensity of 50-100mW / cm² for 30-90s.

9. A method for manufacturing a capacitor according to claim 2, characterized in that: The specific process of segmented vacuum heat treatment in step S5 is as follows: In the first stage, the temperature is raised to 70℃-90℃ at a heating rate of 2-5℃ / min and held for 1-2 hours to remove residual solvent and microbubbles; in the second stage, the temperature is raised to 140℃-160℃ at a heating rate of 1-3℃ / min and held for 3-5 hours to achieve complete solidification of the electrolyte and strengthen the interfacial chemical bonding; during the cooling process, the vacuum degree in the furnace is maintained until the temperature drops below 80℃, and then the pressure is naturally released to atmospheric pressure.

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