A solid-state capacitor and a method for preparing the same

Abstract

The present invention discloses a solid-state capacitor and a preparation method thereof, wherein the preparation method comprises the following steps: (1) core package winding: inserting electrolytic paper between an anode foil and a cathode foil, and winding the core package; (2) repairing step: immersing the core package in a chemical forming liquid for repairing treatment; (3) drying step: drying the core package obtained in step (2); (4) impregnation step: immersing the core package obtained in step (3) in a first impregnation liquid for impregnation treatment; drying; immersing the core package in a second impregnation liquid for impregnation treatment, and drying; (5) polymerization step: immersing the core package obtained in step (4) in an oxidizing liquid for polymerization; and (6) assembling waist and aging treatment.

Description

Technical Field

[0001] The present invention relates to the technical field of capacitor manufacturing, and in particular to a solid-state capacitor and a preparation method thereof. Background Art

[0002] Aluminum electrolytic capacitors, as energy storage components widely used in electronic devices, have the advantages of low cost and high capacitance density, but the inherent defects of their liquid electrolytes severely limit their reliability and application scenarios.

[0003] To overcome the limitations of liquid capacitors, solid-state capacitors have emerged by replacing liquid electrolytes with solid conductive materials. They are mainly divided into two categories: conductive polymer aluminum electrolytic capacitors and organic semiconductor capacitors. Solid-state structures can theoretically avoid problems such as liquid volatilization and high-frequency impedance, but existing technologies still have significant bottlenecks: First, the leakage current of solid-state capacitors is generally high. The root cause is the presence of microscopic defects at the interface between the conductive polymer and aluminum oxide, which leads to local electric field distortion and induces leakage conduction channels; second, polymer materials are prone to chain segment breakage or oxidative decomposition at high temperatures, resulting in insufficient conductive network stability and reduced capacity retention; third, existing impregnation processes make it difficult to achieve uniform compounding of solid conductive materials, which cannot meet the parameter consistency requirements of precision circuits.

[0004] In response to the above contradictions, the industry urgently needs to build a new generation of solid-state capacitors that can achieve breakthroughs in precise suppression of leakage current, high-temperature self-healing capabilities, and process controllability while maintaining the environmental friendliness and high-frequency advantages of solid-state structures. Summary of the Invention

[0005] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of this application to avoid obscuring the purpose of this section, the abstract and the title of the invention, and such simplifications or omissions should not be used to limit the scope of the present invention.

[0006] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0007] Therefore, the purpose of the present invention is to overcome the deficiencies in the prior art and provide a solid-state capacitor and a method for preparing the same.

[0008] In order to solve the above technical problems, the present invention provides the following technical solutions: comprising:

[0009] A method for preparing a solid-state capacitor, comprising the following steps:

[0010] (1) Core package winding: insert electrolytic paper between the anode foil and the cathode foil and wind them into a core package;

[0011] (2) Repair step: immerse the core package in the chemical solution for repair treatment;

[0012] (3) Drying step: drying the core package from step (2);

[0013] (4) Impregnation step: immersing the core package of step (3) in the first impregnation liquid for impregnation treatment; drying; immersing in the second impregnation liquid for impregnation treatment, and drying;

[0014] (5) Polymerization step: immersing the core package of step (4) in an oxidizing solution for polymerization;

[0015] (6) Assemble the waist and perform aging treatment.

[0016] As an optimization, the density of the electrolytic paper in step (1) is 0.45-0.7 g / cm 3 , thickness is 50μm, and the raw material is Manila hemp fiber.

[0017] As an optimization, the chemical conversion liquid in step (2) comprises pure water, ammonium adipate, phosphoric acid, boric acid and additives; the mass ratio of each component is: pure water 96.5%-97%, ammonium adipate 1.6%-1.8%, phosphoric acid 0.8%-1.0%, boric acid 0.3%-0.4%, additive aqueous solution 0.2%-0.4%; the additive is citric acid, phosphate ester, phenol or isopropyl alcohol.

[0018] As an optimization, the first impregnation solution in step (4) is composed of the following raw materials in weight percentage: 10%-15% thiophene, 10%-15% 3,4-ethylenedioxythiophene, and 70%-80% ethanol.

[0019] As an optimization, the second impregnation solution is composed of the following raw materials in weight percentage: 35%-45% thiophene derivatives, 5%-10% modified carbon microspheres, and 45%-60% N,N-dimethylformamide.

[0020] As an optimization, the thiophene derivative is one or more of thiophene-3,4-diol, 3-thiophene methanol, 3,4-di(2-hydroxyethyl)thiophene or thiophene-3-ol.

[0021] As an optimization, the oxidation solution in step (5) is composed of the following raw materials in weight percentage: ammonium persulfate 10%-20%, 37wt% hydrochloric acid 1%-5%, sodium dodecylbenzenesulfonate 10%-12%, EVA 5%-10%, and isobutanol 53%-74%.

[0022] As an optimization, the polymerization conditions in step (5) are: 40-80°C.

[0023] As an optimization, the aging treatment in step (6) is a step-up aging, which specifically includes the following steps: the first stage: room temperature, 15V treatment for 30 minutes; the second stage: 80-90℃, 30V treatment for 2 hours; the third stage: 100-110℃, 35V treatment for 1 hour; the fourth stage: 120-130℃, 40V treatment for 20 minutes.

[0024] As an optimization, the preparation method of the modified carbon microspheres is as follows: glucose, sodium oleate, P123, and pure water are mixed for 2-3 hours, transferred to a high-pressure reactor, reacted at 150-160°C for 24 hours, washed and dried, and then treated in a nitrogen-protected, 500°C tube furnace for 2-3 hours to obtain hollow carbon nanospheres; the molar ratio of glucose, sodium oleate, and P123 is 1:(7.5-9.5):(0.45-0.65); the amount of pure water added is 30-40 times that of glucose; the hollow carbon nanospheres, tetrahydrofuran, and 1-pyreneboric acid are ultrasonically mixed at a mass ratio of 1:(0.5-0.7):(150-200) for 2-3 hours, and then stirred for 10-12 hours, filtered, washed, and dried to obtain modified carbon microspheres.

[0025] The present invention also provides a solid-state capacitor prepared according to any of the above preparation methods.

[0026] Beneficial effects of the present invention:

[0027] (1) The repair step forms a dense oxide film through the conductivity of the chemical solution, reduces defects, improves the pressure resistance of the product, repairs the oxide film, and reduces the leakage current of the product.

[0028] (2) The aging process is repaired by applying different voltages at room temperature and high temperature at the same time, so that the product can achieve good consistency when testing the leakage current during overvoltage testing, and the parameter differences are not large.

[0029] (3) At the same time, through a double impregnation process - first, thiophene and PEDOT are used to form a highly conductive polymer substrate, and then thiophene derivatives and modified carbon microspheres are introduced to construct a three-dimensional conductive network; borate bonds are introduced on the surface of the modified carbon microspheres through π-π stacking, forming reversible borate bonds with thiophene alcohol. This not only fixes polythiophene to the surface of the carbon microsphere skeleton through covalent bonds, but also quickly reorganizes after local fracture under high-frequency current impact, maintains the integrity of the three-dimensional conductive network, realizes interface self-repair, and extends the service life of solid-state capacitors, which is expected to be applied in high-frequency scenarios. DETAILED DESCRIPTION

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0031] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0032] Secondly, the term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive of other embodiments.

[0033] The glucose used in the present invention is α-D-glucose, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; the P123 used is PEO-PPO-PEO, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; the EVA is ethylene-vinyl acetate copolymer, brand Levapren 500; the remaining raw materials are all commonly commercially available in the art unless otherwise specified.

[0034] Example 1: This example provides a method for preparing a solid-state capacitor, specifically:

[0035] (1) Core wrapping: Electrolytic paper is inserted between the anode foil and the cathode foil and wound into a core wrapping; the density of the electrolytic paper is 0.45g / cm 3 , thickness is 50μm, and the raw material is Manila hemp fiber;

[0036] (2) Repair step: immerse the core package in a chemical solution for repair treatment; the chemical solution contains pure water, ammonium adipate, phosphoric acid, boric acid and additives; the mass ratio of each component is: pure water 96.5%, ammonium adipate 1.8%, phosphoric acid 1.0%, boric acid 0.4%, additive aqueous solution 0.3%; the additive is phosphate ester;

[0037] (3) Drying step: drying the core package from step (2);

[0038] (4) Impregnation step: immerse the core package of step (3) in the first impregnation liquid for impregnation treatment; dry; immerse in the second impregnation liquid for impregnation treatment, and dry; the first impregnation liquid is composed of the following raw materials in weight percentage: 10% thiophene, 10% 3,4 Ethylene dioxythiophene, 80% ethanol; the second impregnation liquid is composed of the following raw materials in weight percentage: 35% thiophene derivative, 5% modified carbon microspheres, 60% N,N-dimethylformamide; the thiophene derivative is 3-thiophene methanol; the preparation method of the modified carbon microspheres is: glucose, sodium oleate, P123, and pure water are mixed for 3 hours, transferred to a high-pressure reactor, reacted at 160°C for 24 hours, washed and dried, and then treated in a nitrogen-protected, 500°C tube furnace for 3 hours to obtain hollow carbon nanospheres; the molar ratio of glucose, sodium oleate, and P123 is 1:7.5:0.45; the amount of pure water added is 30 times that of glucose; the hollow carbon nanospheres, tetrahydrofuran, and 1-pyrene boric acid are ultrasonically mixed at a mass ratio of 1:0.5:150 for 3 hours, and then stirred for 12 hours, filtered, washed, and dried to obtain modified carbon microspheres;

[0039] (5) Polymerization step: immersing the core package of step (4) in an oxidizing solution for polymerization; the polymerization condition is: 80°C; the oxidizing solution is composed of the following raw materials in weight percentage: 10% ammonium persulfate, 1% 37wt% hydrochloric acid, 10% sodium dodecylbenzenesulfonate, 5% EVA, and 74% isobutanol;

[0040] (6) Assembling the waist and aging treatment; the aging treatment is a step-up aging, which specifically includes the following steps: the first stage: room temperature, 15V treatment for 30 minutes; the second stage 90℃, 30V treatment for 2 hours; the third stage 110℃, 35V treatment for 1 hour; the fourth stage 130℃, 40V treatment for 20 minutes.

[0041] Example 2: This example provides a method for preparing a solid-state capacitor, specifically:

[0042] (1) Core wrapping: Electrolytic paper is inserted between the anode foil and the cathode foil and wound into a core wrapping; the density of the electrolytic paper is 0.6g / cm 3 , thickness is 50μm, and the raw material is Manila hemp fiber;

[0043] (2) Repair step: immerse the core package in a chemical solution for repair treatment; the chemical solution contains pure water, ammonium adipate, phosphoric acid, boric acid and additives; the mass ratio of each component is: pure water 96.7%, ammonium adipate 1.7%, phosphoric acid 0.9%, boric acid 0.35%, additive aqueous solution 0.35%; the additive is citric acid;

[0044] (3) Drying step: drying the core package from step (2);

[0045] (4) Impregnation step: immerse the core package of step (3) in a first impregnation liquid for impregnation treatment; dry; immerse in a second impregnation liquid for impregnation treatment, and dry; the first impregnation liquid is composed of the following raw materials in weight percentage: 12% thiophene, 12% 3,4 Ethylene dioxythiophene, 76% ethanol; the second impregnation liquid is composed of the following raw materials in weight percentage: 40% thiophene derivative, 7% modified carbon microspheres, 53% N,N-dimethylformamide; the thiophene derivative is thiophene-3,4-diol; the preparation method of the modified carbon microspheres is: glucose, sodium oleate, P123, and pure water are mixed for 2.5 hours, transferred to a high-pressure reactor, reacted at 155°C for 24 hours, washed and dried, and then treated in a nitrogen-protected, 500°C tube furnace for 2.5 hours to obtain hollow carbon nanospheres; the molar ratio of glucose, sodium oleate, and P123 is 1:8:0.5; the amount of pure water added is 35 times that of glucose; the hollow carbon nanospheres, tetrahydrofuran, and 1-pyreneboric acid are ultrasonically mixed at a mass ratio of 1:0.6:170 for 2.5 hours, and then stirred for 11 hours, filtered, washed, and dried to obtain modified carbon microspheres;

[0046] (5) Polymerization step: the core package of step (4) is immersed in an oxidizing solution and then taken out, and then dried and polymerized at 60°C; the oxidizing solution is composed of the following raw materials in weight percentage: 15% ammonium persulfate, 5% hydrochloric acid (37wt%), 11% sodium dodecylbenzene sulfonate, 7% EVA, and 62% isobutanol;

[0047] (6) Assembling the waist and aging treatment; the aging treatment is a step-up aging treatment, which specifically includes the following steps: the first stage: room temperature, 15V treatment for 30 minutes; the second stage: 85℃, 30V treatment for 2 hours; the third stage: 105℃, 35V treatment for 1 hour; the fourth stage: 125℃, 40V treatment for 20 minutes.

[0048] Example 3: This example provides a method for preparing a solid-state capacitor, specifically:

[0049] (1) Core wrapping: Electrolytic paper is inserted between the anode foil and the cathode foil and wound into a core wrap; the density of the electrolytic paper is 0.7g / cm 3 , thickness is 50μm, and the raw material is Manila hemp fiber;

[0050] (2) Repair step: immerse the core package in a chemical solution for repair treatment; the chemical solution contains pure water, ammonium adipate, phosphoric acid, boric acid and additives; the mass ratio of each component is: pure water 97%, ammonium adipate 1.6%, phosphoric acid 0.8%, boric acid 0.3%, additive aqueous solution 0.3%; the additive is phenol;

[0051] (3) Drying step: drying the core package from step (2);

[0052] (4) Impregnation step: immerse the core package of step (3) in the first impregnation liquid for impregnation treatment; dry; immerse in the second impregnation liquid for impregnation treatment, and dry; the first impregnation liquid is composed of the following raw materials in weight percentage: 15% thiophene, 15% 3,4 Ethylene dioxythiophene, 70% ethanol; the second impregnation liquid is composed of the following raw materials in weight percentage: 45% thiophene derivative, 10% modified carbon microspheres, 45% N,N-dimethylformamide; the thiophene derivative is thiophene-3-ol; the preparation method of the modified carbon microspheres is: glucose, sodium oleate, P123, and pure water are mixed for 2 hours, transferred to a high-pressure reactor, reacted at 150°C for 24 hours, washed and dried, and then treated in a nitrogen-protected, 500°C tube furnace for 2 hours to obtain hollow carbon nanospheres; the molar ratio of glucose, sodium oleate, and P123 is 1:9.5:0.65; the amount of pure water added is 40 times that of glucose; the hollow carbon nanospheres, tetrahydrofuran, and 1-pyreneboric acid are ultrasonically mixed at a mass ratio of 1:0.7:200 for 2 hours, and then stirred for 10 hours, filtered, washed, and dried to obtain modified carbon microspheres;

[0053] (5) Polymerization step: immersing the core package of step (4) in an oxidizing solution for polymerization; the polymerization condition is: 40°C; the oxidizing solution is composed of the following raw materials in weight percentage: 20% ammonium persulfate, 5% hydrochloric acid (37wt%), 12% sodium dodecylbenzene sulfonate, 10% EVA, and 53% isobutanol;

[0054] (6) Assembling the waist and aging treatment; the aging treatment is a step-up aging, which specifically includes the following steps: the first stage: room temperature, 15V treatment for 30 minutes; the second stage 80℃, 30V treatment for 2 hours; the third stage 100℃, 35V treatment for 1 hour; the fourth stage 120℃, 40V treatment for 20 minutes.

[0055] Example 4: This example provides a method for preparing a solid-state capacitor, specifically:

[0056] (1) Core wrapping: Electrolytic paper is inserted between the anode foil and the cathode foil and wound into a core wrap; the density of the electrolytic paper is 0.7g / cm 3 , thickness is 50μm, and the raw material is Manila hemp fiber;

[0057] (2) Repair step: immerse the core package in a chemical solution for repair treatment; the chemical solution contains pure water, ammonium adipate, phosphoric acid, boric acid and additives; the mass ratio of each component is: pure water 97%, ammonium adipate 1.6%, phosphoric acid 0.8%, boric acid 0.3%, additive aqueous solution 0.3%; the additive is isopropyl alcohol;

[0058] (3) Drying step: drying the core package from step (2);

[0059] (4) Impregnation step: immerse the core package of step (3) in the first impregnation liquid for impregnation treatment; dry; immerse in the second impregnation liquid for impregnation treatment, and dry; the first impregnation liquid is composed of the following raw materials in weight percentage: 15% thiophene, 15% 3,4-ethylenedioxythiophene, and 70% ethanol; the second impregnation liquid is composed of the following raw materials in weight percentage: 45% thiophene derivatives, 10% modified carbon microspheres, and 45% N,N-dimethylformamide; the thiophene derivative is a mixture of thiophene-3,4-diol and 3-thiophene methanol in a mass ratio of 1:1; the preparation method of the modified carbon microspheres is: mix glucose, sodium oleate, P123, and pure water for 2.3 hours, transfer to a high-pressure reactor, and heat for 1 hour. The reaction was carried out at 57°C for 24 hours, and after washing and drying, hollow carbon nanospheres were obtained by treating them in a tube furnace at 500°C under nitrogen protection for 2.8 hours. The molar ratio of glucose, sodium oleate, and P123 was 1:7.2:0.6. The amount of pure water added was 37 times that of glucose. The hollow carbon nanospheres, tetrahydrofuran, and 1-pyreneboric acid were ultrasonically mixed at a mass ratio of 1:0.55:155 for 2 hours, and then stirred for 11 hours. The modified carbon microspheres were filtered, washed, and dried to obtain the modified carbon microspheres.

[0060] (5) Polymerization step: immersing the core package of step (4) in an oxidizing solution for polymerization; the polymerization condition is: 40°C; the oxidizing solution is composed of the following raw materials in weight percentage: 20% ammonium persulfate, 5% hydrochloric acid (37wt%), 12% sodium dodecylbenzene sulfonate, 10% EVA, and 53% isobutanol;

[0061] (6) Assembling the waist and aging treatment; the aging treatment is a step-up aging, which specifically includes the following steps: the first stage: room temperature, 15V treatment for 30 minutes; the second stage 80℃, 30V treatment for 2 hours; the third stage 100℃, 35V treatment for 1 hour; the fourth stage 120℃, 40V treatment for 20 minutes.

[0062] Comparative Example 1: This comparative example differs from Example 2 in that step (2) is omitted and the core package of step (1) is not repaired. Specifically:

[0063] (1) Core wrapping: Electrolytic paper is inserted between the anode foil and the cathode foil and wound into a core wrapping; the density of the electrolytic paper is 0.6g / cm 3 , thickness is 50μm, and the raw material is Manila hemp fiber;

[0064] (2) Drying step: drying the core package obtained in step (1);

[0065] (3) Impregnation step: immerse the core package of step (2) in the first impregnation liquid for impregnation treatment; dry; immerse in the second impregnation liquid for impregnation treatment, and dry; the first impregnation liquid is composed of the following raw materials in weight percentage: 12% thiophene, 12% 3,4 Ethylene dioxythiophene, 76% ethanol; the second impregnation liquid is composed of the following raw materials in weight percentage: 40% thiophene derivative, 7% modified carbon microspheres, 53% N,N-dimethylformamide; the thiophene derivative is thiophene-3,4-diol; the preparation method of the modified carbon microspheres is: glucose, sodium oleate, P123, and pure water are mixed for 2.5 hours, transferred to a high-pressure reactor, reacted at 155°C for 24 hours, washed and dried, and then treated in a nitrogen-protected, 500°C tube furnace for 2.5 hours to obtain hollow carbon nanospheres; the molar ratio of glucose, sodium oleate, and P123 is 1:8:0.5; the amount of pure water added is 35 times that of glucose; the hollow carbon nanospheres, tetrahydrofuran, and 1-pyreneboric acid are ultrasonically mixed at a mass ratio of 1:0.6:170 for 2.5 hours, and then stirred for 11 hours, filtered, washed, and dried to obtain modified carbon microspheres;

[0066] (4) Polymerization step: the core package of step (3) is immersed in an oxidizing solution and then taken out, and then dried and polymerized at 60°C; the oxidizing solution is composed of the following raw materials in weight percentage: 15% ammonium persulfate, 5% 37wt% hydrochloric acid, 11% sodium dodecylbenzene sulfonate, 7% EVA, and 62% isobutanol;

[0067] (5) Assembling the waist and aging treatment; the aging treatment is a step-up aging, which specifically includes the following steps: the first stage: room temperature, 15V treatment for 30 minutes; the second stage: 85℃, 30V treatment for 2 hours; the third stage: 105℃, 35V treatment for 1 hour; the fourth stage: 125℃, 40V treatment for 20 minutes.

[0068] The remaining steps and processes are all referred to Example 2 to obtain the solid-state capacitor of this comparative example.

[0069] Comparative Example 2: This comparative example differs from Example 2 in that it does not contain modified carbon microspheres. Specifically:

[0070] (1) Core wrapping: Electrolytic paper is inserted between the anode foil and the cathode foil and wound into a core wrapping; the density of the electrolytic paper is 0.6g / cm 3 , thickness is 50μm, and the raw material is Manila hemp fiber;

[0071] (2) Repair step: immerse the core package in a chemical solution for repair treatment; the chemical solution contains pure water, ammonium adipate, phosphoric acid, boric acid and additives; the mass ratio of each component is: pure water 96.7%, ammonium adipate 1.7%, phosphoric acid 0.9%, boric acid 0.35%, additive aqueous solution 0.35%; the additive is citric acid;

[0072] (3) Drying step: drying the core package from step (2);

[0073] (4) Impregnation step: immersing the core package of step (3) in a first impregnation liquid for impregnation treatment; drying; immersing in a second impregnation liquid for impregnation treatment, and drying; the first impregnation liquid is composed of the following raw materials in weight percentage: 12% thiophene, 12% 3,4-ethylenedioxythiophene, and 76% ethanol; the second impregnation liquid is composed of the following raw materials in weight percentage: 40% thiophene derivative and 60% N,N-dimethylformamide; the thiophene derivative is thiophene-3,4-diol;

[0074] (5) Polymerization step: the core package of step (4) is immersed in an oxidizing solution and then taken out, and then dried and polymerized at 60°C; the oxidizing solution is composed of the following raw materials in weight percentage: 15% ammonium persulfate, 5% hydrochloric acid (37wt%), 11% sodium dodecylbenzene sulfonate, 7% EVA, and 62% isobutanol;

[0075] (6) Assembling the waist and aging treatment; the aging treatment is a step-up aging treatment, which specifically includes the following steps: the first stage: room temperature, 15V treatment for 30 minutes; the second stage: 85℃, 30V treatment for 2 hours; the third stage: 105℃, 35V treatment for 1 hour; the fourth stage: 125℃, 40V treatment for 20 minutes.

[0076] The remaining steps and processes are all referred to Example 2 to obtain the solid-state capacitor of this comparative example.

[0077] Comparative Example 3: This comparative example differs from Example 2 in that it does not contain thiophene alcohol. Specifically:

[0078] (1) Core wrapping: Electrolytic paper is inserted between the anode foil and the cathode foil and wound into a core wrapping; the density of the electrolytic paper is 0.6g / cm 3 , thickness is 50μm, and the raw material is Manila hemp fiber;

[0079] (2) Repair step: immerse the core package in a chemical solution for repair treatment; the chemical solution contains pure water, ammonium adipate, phosphoric acid, boric acid and additives; the mass ratio of each component is: pure water 96.7%, ammonium adipate 1.7%, phosphoric acid 0.9%, boric acid 0.35%, additive aqueous solution 0.35%; the additive is citric acid;

[0080] (3) Drying step: drying the core package from step (2);

[0081] (4) Impregnation step: immerse the core package of step (3) in a first impregnation liquid for impregnation treatment; dry; immerse in a second impregnation liquid for impregnation treatment, and dry; the first impregnation liquid is composed of the following raw materials in weight percentage: 12% thiophene, 12% 3,4 Ethylene dioxythiophene, 76% ethanol; the second impregnation liquid is composed of the following raw materials in weight percentage: 40% thiophene derivative, 7% modified carbon microspheres, 53% N,N-dimethylformamide; the thiophene derivative is thiophene; the preparation method of the modified carbon microspheres is: glucose, sodium oleate, P123, and pure water are mixed for 2.5 hours, transferred to a high-pressure reactor, reacted at 155°C for 24 hours, washed and dried, and then treated in a nitrogen-protected, 500°C tube furnace for 2.5 hours to obtain hollow carbon nanospheres; the molar ratio of glucose, sodium oleate, and P123 is 1:8:0.5; the amount of pure water added is 35 times that of glucose; the hollow carbon nanospheres, tetrahydrofuran, and 1-pyreneboric acid are ultrasonically mixed at a mass ratio of 1:0.6:170 for 2.5 hours, and then stirred for 11 hours, filtered, washed, and dried to obtain modified carbon microspheres;

[0082] (5) Polymerization step: the core package of step (4) is immersed in an oxidizing solution and then taken out, and then dried and polymerized at 60°C; the oxidizing solution is composed of the following raw materials in weight percentage: 15% ammonium persulfate, 5% hydrochloric acid (37wt%), 11% sodium dodecylbenzene sulfonate, 7% EVA, and 62% isobutanol;

[0083] (6) Assembling the waist and aging treatment; the aging treatment is a step-up aging treatment, which specifically includes the following steps: the first stage: room temperature, 15V treatment for 30 minutes; the second stage: 85℃, 30V treatment for 2 hours; the third stage: 105℃, 35V treatment for 1 hour; the fourth stage: 125℃, 40V treatment for 20 minutes.

[0084] The remaining steps and processes are all referred to Example 2 to obtain the solid-state capacitor of this comparative example.

[0085] The solid-state capacitors prepared from the embodiment and the comparative example with a voltage of 25 V and 220 μF were selected for performance testing, including initial capacity CAP, equivalent series resistance ESR, leakage current, and average retention of capacitance after 3000 cycles. The results are shown in Table 1.

[0086] Table 1

[0087] CAP (μF) ESR (mΩ) Leakage current (μA) Retention rate (%) Example 1 225 12 37 97.5 Example 2 228 14 37 96.8 Example 3 230 10 40 98.2 Example 4 229 11 39 98.0 Comparative Example 1 219 26 107 82.3 Comparative Example 2 224 31 93 79.5 Comparative Example 3 220 32 84 76.6

[0088] As can be seen from Table 1, the beneficial effects of the present invention are as follows: (1) the repair step forms a dense oxide film through the conductivity of the chemical solution, reduces defects, improves the pressure resistance of the product, repairs the oxide film, and reduces the leakage current of the product. The aging process is repaired by applying different voltages at room temperature and high temperature at the same time, so that the product can obtain good consistency when testing the leakage current of the overvoltage test, and the parameter differences are not large. At the same time, through a double impregnation process - first forming a highly conductive polymer substrate with thiophene and PEDOT, and then introducing thiophene derivatives and modified carbon microspheres to construct a three-dimensional conductive network; the surface of the modified carbon microspheres introduces borate bonds through π-π stacking, and forms reversible borate bonds with thiophene alcohol, which not only fixes the polythiophene to the surface of the carbon microsphere skeleton through covalent bonds, but also quickly reorganizes after local fracture under high-frequency current impact, maintains the integrity of the three-dimensional conductive network, realizes interface self-repair, and extends the service life of the solid-state capacitor, which is expected to be applied in high-frequency scenarios.

[0089] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A solid-state capacitor and a method for preparing the same, characterized in that: The preparation method comprises the following steps: (1) Core package winding: insert electrolytic paper between the anode foil and the cathode foil and wind them into a core package; (2) Repair step: immerse the core package in the chemical solution for repair treatment; (3) Drying step: drying the core package from step (2); (4) Impregnation step: immersing the core package of step (3) in the first impregnation liquid for impregnation treatment; drying; immersing in the second impregnation liquid for impregnation treatment, and drying; The first impregnation solution is composed of the following raw materials in weight percentage: 10%-15% thiophene, 10%-15% 3,4-ethylenedioxythiophene, and 70%-80% ethanol; The second impregnation solution is composed of the following raw materials in weight percentage: 35%-45% thiophene derivative, 5%-10% modified carbon microspheres, and 45%-60% N,N-dimethylformamide; The modified carbon microspheres are prepared by mixing glucose, sodium oleate, P123, and pure water for 2-3 hours, transferring the mixture to a high-pressure reactor, reacting the mixture at 150-160° C. for 24 hours, washing and drying the mixture, and then treating the mixture in a nitrogen-protected, 500° C. tube furnace for 2-3 hours to obtain hollow carbon nanospheres. The molar ratio of glucose, sodium oleate, and P123 is 1:(7.5-9.5):(0.45-0.65); P123 is PEO-PPO-PEO; the hollow carbon nanospheres, tetrahydrofuran, and 1-pyreneboric acid are uniformly mixed by ultrasonication for 2-3 hours at a mass ratio of 1:(0.5-0.7):(150-200), stirring the mixture for 10-12 hours, and filtering, washing, and drying the mixture to obtain the modified carbon microspheres. The thiophene derivative is one or more of thiophene-3,4-diol, 3-thiophene methanol, 3,4-bis(2-hydroxyethyl)thiophene or thiophene-3-ol; (5) Polymerization step: immersing the core package of step (4) in an oxidizing solution for polymerization; (6) Assemble the waist and perform aging treatment.

2. A solid-state capacitor and a method for preparing the same according to claim 1, characterized in that: The density of the electrolytic paper in step (1) is 0.45-0.7 g / cm 3 , thickness is 50μm, and the raw material is Manila hemp fiber.

3. A solid-state capacitor and a method for preparing the same according to claim 1, characterized in that: The chemical conversion liquid in step (2) comprises pure water, ammonium adipate, phosphoric acid, boric acid and an additive; the mass ratio of each component is: pure water 96.5%-97%, ammonium adipate 1.6%-1.8%, phosphoric acid 0.8%-1.0%, boric acid 0.3%-0.4%, and additive aqueous solution 0.2%-0.4%; the additive is one of citric acid, phosphate ester, phenol or isopropyl alcohol.

4. A solid-state capacitor and a method for preparing the same according to claim 1, characterized in that: The oxidizing solution in step (5) is composed of the following raw materials in weight percentage: 10%-20% ammonium persulfate, 1%-5% 37wt% hydrochloric acid, 10%-12% sodium dodecylbenzenesulfonate, 5%-10% EVA, and 53%-74% isobutanol.

5. A solid-state capacitor and a method for preparing the same according to claim 1, characterized in that: The polymerization conditions in step (5) are: 40-80°C.

6. A solid-state capacitor and a method for preparing the same according to claim 1, characterized in that: The aging treatment in step (6) is a step-up aging treatment, which specifically includes the following steps: the first stage: room temperature, 15V treatment for 30 minutes; the second stage: 80-90℃, 30V treatment for 2 hours; the third stage: 100-110℃, 35V treatment for 1 hour; the fourth stage: 120-130℃, 40V treatment for 20 minutes.

7. A solid capacitor prepared according to the preparation method according to any one of claims 1 to 6.