Solid aluminum electrolytic capacitor and preparation method thereof

Abstract

A solid aluminum electrolytic capacitor comprises a core package and a shell, and the core package is arranged in the shell in a sealed mode. A conductive high-molecular polymer film is formed in the core package, the conductive high-molecular polymer film comprises PEDOT: PSS, hexadecyl trimethyl ammonium chloride and precious metal nanoparticles, and the precious metal nanoparticles comprise one or more of gold nano bipyramids, gold nanowires, gold nanospheres or silver nanowires; the hexadecyl trimethyl ammonium chloride and the noble metal nanoparticles are uniformly distributed in the PEDOT: PSS, and the total weight of the hexadecyl trimethyl ammonium chloride and the noble metal nanoparticles does not exceed 8% of the weight of the PEDOT: PSS. According to the preparation method, hexadecyl trimethyl ammonium chloride is added into the PEDOT: PSS thin film doped with the noble metal nanoparticles, so that the capacity and the cycling stability of the prepared solid aluminum electrolytic capacitor are further improved.

Description

Technical Field

[0001] The present invention relates to an aluminum electrolytic capacitor, and in particular to a solid aluminum electrolytic capacitor and a preparation method thereof. Background Art

[0002] In solid aluminum electrolytic capacitors, conductive polymers generally use PEDOT film or PEDOT:PSS film. The toughness of this film is relatively poor. During the charge and discharge cycle of solid aluminum electrolytic capacitors, PEDOT film or PEDOT:PSS film will expand and contract, but after multiple cycles, PEDOT film or PEDOT:PSS film can easily peel off from the anode foil, thus affecting the lead-out of the capacitor. At the same time, the mechanical properties of PEDOT film or PEDOT:PSS film are poor, and self-ignition is prone to occur when the solid aluminum electrolytic capacitor is subjected to external mechanical shock or vibration. In order to solve such problems, such as patent CN114783775A, a solid aluminum electrolytic capacitor and its preparation method; doping silver nanowires in PEDOT:PSS film can solve the problem of poor mechanical properties of PEDOT:PSS film, but adding silver nanowires to PEDOT:PSS dispersion makes it difficult for PEDOT:PSS to be evenly dispersed in the dispersion; when PEDOT:PSS is formed into a film, the uniformity of the film will deteriorate, making the capacitance stability of the prepared solid aluminum electrolytic capacitor low. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a solid aluminum electrolytic capacitor and a preparation method thereof.

[0004] In order to solve the above technical problems, the technical solution proposed by the present invention is: a solid aluminum electrolytic capacitor, comprising a core package and a shell, wherein the core package is sealed in the shell; a conductive polymer film is formed in the core package, wherein the conductive polymer film comprises PEDOT:PSS, hexadecyltrimethylammonium chloride and precious metal nanoparticles, wherein the precious metal nanoparticles comprise one or more of gold nanobipyramids, gold nanowires, gold nanospheres or silver nanowires; the hexadecyltrimethylammonium chloride and the precious metal nanoparticles are uniformly distributed in the PEDOT:PSS, and the total weight of the hexadecyltrimethylammonium chloride and the precious metal nanoparticles does not exceed 8% of the PEDOT:PSS.

[0005] In the above-mentioned solid aluminum electrolytic capacitor, preferably, the weight of the hexadecyltrimethylammonium chloride is 1%-5% of the weight of the PEDOT:PSS.

[0006] In the above-mentioned solid aluminum electrolytic capacitor, preferably, the weight of the noble metal nanoparticles is 1%-5% of the weight of PEDOT:PSS.

[0007] In the above-mentioned solid aluminum electrolytic capacitor, preferably, the weight of the hexadecyltrimethylammonium chloride is 1%-5% of the weight of the PEDOT:PSS.

[0008] In the above-mentioned solid aluminum electrolytic capacitor, preferably, the weight of the noble metal nanoparticles is 1%-5% of the weight of PEDOT:PSS.

[0009] A method for preparing a solid aluminum electrolytic capacitor comprises the following steps: 1) Add the precious metal nanoparticles into the hexadecyltrimethylammonium chloride solution and stir evenly; set aside; 2) adding the hexadecyltrimethylammonium chloride solution mixed with the noble metal nanoparticles to the PEDOT:PSS dispersion, stirring evenly to form a ternary mixed solution; and setting aside; the total weight of the hexadecyltrimethylammonium chloride and the noble metal nanoparticles does not exceed 8% of the PEDOT:PSS; 3) Dry the core package at 45-120℃; 4) The core bag is impregnated with the ternary mixed solution of step 2), and the core bag is dried at a temperature of room temperature to 80°C; 5) The core package is sealed and arranged in the housing.

[0010] In the above-mentioned method for preparing a solid aluminum electrolytic capacitor, preferably, in the PEDOT:PSS dispersion, the weight percentage of PEDOT:PSS is 1%-8%.

[0011] In the above-mentioned method for preparing a solid aluminum electrolytic capacitor, preferably, the solvent of the hexadecyltrimethylammonium chloride solution in step 1) is the same as the solvent of the PEDOT:PSS dispersion in step 2).

[0012] In the above-mentioned method for preparing the solid aluminum electrolytic capacitor, preferably, in step 4), the core package is first impregnated with a solvent of a PEDOT:PSS dispersion before being impregnated with the ternary mixed solution.

[0013] In the above-mentioned method for preparing a solid aluminum electrolytic capacitor, preferably, after the step 4) is completed, the core is immersed in an electrolyte.

[0014] Compared with the prior art, the advantages of the present invention are as follows: in the present invention, by adding hexadecyltrimethylammonium chloride to the PEDOT:PSS film doped with precious metal nanoparticles, the problem of rough and uneven surface of the PEDOT:PSS film doped with precious metal nanoparticles is well solved; thereby, the capacity and cycle stability of the prepared solid aluminum electrolytic capacitor are further improved. DETAILED DESCRIPTION

[0015] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively and carefully in combination with preferred embodiments below, but the protection scope of the present invention is not limited to the following specific embodiments.

[0016] It should be noted that when an element is described as being "fixed, fixed, connected or connected to" another element, it can be directly fixed, fixed, connected or connected to the other element, or it can be indirectly fixed, fixed, connected or connected to the other element through other intermediate connectors.

[0017] Unless otherwise defined, all the professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention. Example 1

[0018] A solid aluminum electrolytic capacitor comprises a core package and a shell, wherein the core package is sealed in the shell; a conductive high molecular polymer film is formed in the core package, and the conductive high molecular polymer film comprises PEDOT:PSS, hexadecyltrimethylammonium chloride and noble metal nanoparticles. In this embodiment, the noble metal nanoparticles are gold nanobipyramids; the hexadecyltrimethylammonium chloride and the gold nanobipyramids are uniformly distributed in the PEDOT:PSS, and the total weight of the hexadecyltrimethylammonium chloride and the noble metal nanoparticles does not exceed 8% of the PEDOT:PSS.

[0019] In this embodiment, the noble metal nanoparticles may also be one or more of gold nanowires, gold nanospheres, and silver nanowires.

[0020] In this embodiment, the weight of hexadecyltrimethylammonium chloride is 5% of the weight of PEDOT:PSS; the weight of the noble metal nanoparticles is 3% of the weight of PEDOT:PSS. In other embodiments, the weight of hexadecyltrimethylammonium chloride is generally 1%-5% of the weight of PEDOT:PSS. The weight of the noble metal nanoparticles is 1%-5% of the weight of PEDOT:PSS.

[0021] In this embodiment, hexadecyl trimethyl ammonium chloride as a cationic surfactant can disperse and stabilize the gold nanobipyramids through inter-ionic forces; hexadecyl trimethyl ammonium chloride can also interact with the negatively charged PSS in PEDOT:PSS through the Coulomb force between charges, thereby combining PEDOT:PSS and precious metal nanoparticles. In addition, hexadecyl trimethyl ammonium chloride as a surfactant can not only improve the effect of the core containing the mixed solution, but also open the chain of PSS through inter-ionic forces, thereby exposing more conductive PEDOT; after the exposed PEDOT combines with the gold nanobipyramids, the conductivity of the film with PEDOT:PSS as the main body is improved; thereby reducing the internal resistance of the solid aluminum electrolytic capacitor.

[0022] In this embodiment, hexadecyl trimethyl ammonium chloride can combine PEDOT:PSS and noble metal nanoparticles together, and gold nanobipyramids can be evenly dispersed in the hexadecyl trimethyl ammonium chloride solution, and hexadecyl trimethyl ammonium chloride can stabilize the gold nanobipyramids. In this way, when forming a conductive polymer film, the gold nanobipyramids are not easy to cause agglomeration, so that the conductive polymer film formed inside the core package is more uniform than when only noble metal nanoparticles are added.

[0023] At the same time, the gold nanobipyramids are evenly dispersed in the hexadecyltrimethylammonium chloride solution through the inter-ionic force, and then can be evenly distributed in the conductive polymer film with PEDOT:PSS as the main body through the action of hexadecyltrimethylammonium chloride. When the solid aluminum electrolytic capacitor is in the charge and discharge cycle, the PEDOT:PSS film is constantly expanding and contracting, and the gold nanobipyramids evenly dispersed in the PEDOT:PSS film can play a supporting role, thereby improving the charge and discharge cycle performance of the solid aluminum electrolytic capacitor.

[0024] This embodiment also provides a method for preparing a solid aluminum electrolytic capacitor, comprising the following steps: 1) Add the precious metal nanoparticles into the hexadecyltrimethylammonium chloride solution and stir evenly; set aside; 2) Adding the hexadecyltrimethylammonium chloride solution mixed with precious metal nanoparticles to the PEDOT:PSS dispersion, stirring evenly to form a ternary mixed solution; set aside; the total weight of the hexadecyltrimethylammonium chloride and the precious metal nanoparticles does not exceed 8% of the PEDOT:PSS; in this embodiment, the weight percentage of PEDOT:PSS in the PEDOT:PSS dispersion is 5%; in other embodiments, the weight percentage of PEDOT:PSS in the PEDOT:PSS dispersion can be 1%-8%.

[0025] 3) Dry the core package at 45-120℃; 4) The core bag is impregnated with the ternary mixed solution of step 2), and the core bag is dried at a temperature between room temperature and 80°C.

[0026] In this embodiment, in step 4), the core package can be impregnated with the solvent of the PEDOT:PSS dispersion before being impregnated with the ternary mixed solution. In this way, during the impregnation, as the first impregnated solvent evaporates, the ternary mixed solution can more easily reach the depth of the core package, so that the core package is impregnated with more conductive polymer.

[0027] After step 4) is completed, a conductive high polymer film is formed in the core package, and the core package is immersed in electrolyte; the electrolyte can repair the damaged oxide film on the surface of the anode foil during the preparation of the aluminum electrolytic capacitor to a certain extent, thereby reducing the leakage current.

[0028] 5) The core package is sealed and arranged in the housing.

[0029] In this embodiment, the solvent of the hexadecyltrimethylammonium chloride solution in step 1) is the same as the solvent of the PEDOT:PSS dispersion in step 2).

[0030] In this embodiment, by adding hexadecyltrimethylammonium chloride to the PEDOT:PSS film doped with precious metal nanoparticles, the problem of rough and uneven surface of the PEDOT:PSS film doped with precious metal nanoparticles is well solved; thereby, the capacity and cycle stability of the prepared solid-state aluminum electrolytic capacitor are further improved.

[0031] Comparative Example 1 In Comparative Example 1, the PEDOT:PSS film is doped with gold nanobipyramids only, but not with hexadecyltrimethylammonium chloride; the rest is the same as in Example 1. Example 2

[0032] In this embodiment, silver nanowires are used to replace gold nanobipyramids, and the rest is the same as in Embodiment 1.

[0033] Comparative Example 2 In Comparative Example 2, the PEDOT:PSS film is doped with silver nanowires only, but not with hexadecyltrimethylammonium chloride; the rest is the same as in Example 2. Example 3

[0034] In this embodiment, gold nanowires are used to replace gold nanobipyramids, and the rest is the same as in Embodiment 1.

[0035] Comparative Example 3 In Comparative Example 2, the PEDOT:PSS film is doped with gold nanowires only, but not with hexadecyltrimethylammonium chloride; the rest is the same as in Example 2. Example 4

[0036] In this embodiment, gold nanospheres are used to replace gold nanobipyramids, and the rest is the same as in Embodiment 1.

[0037] Comparative Example 4 In Comparative Example 2, the PEDOT:PSS film is doped with gold nanospheres only, but not with hexadecyltrimethylammonium chloride; the rest is the same as in Example 2.

[0038] 20 products of Example 1, Comparative Example 1, Example 2, Comparative Example 2, Example 3, Comparative Example 3, Example 4 and Comparative Example 4 with 110V and 400μF were selected respectively, and their average capacitance CAP (μF), internal resistance ESR (mΩ) and capacitance retention rate after 5000 cycles were measured respectively. The results are shown in the following table.

[0039] CAP (μF) ESR (mΩ) Capacitance retention after 5000 cycles Example 1 480.6 21.1 89.7 Comparative Example 1 410.2 45.3 84.3 Example 2 463.4 25.2 85.4 Comparative Example 2 420.5 47.4 80.1 Example 3 460.8 25.7 86.2 Comparative Example 3 425.5 46.6 80.7 Example 4 458.6 35.5 91.4 Comparative Example 4 416.3 65.2 85.6 .

Claims

1. A solid aluminum electrolytic capacitor, characterized in that: The invention comprises a core package and an outer shell, wherein the core package is sealed in the outer shell; a conductive high molecular polymer film is formed in the core package, wherein the conductive high molecular polymer film comprises PEDOT:PSS, hexadecyltrimethylammonium chloride and noble metal nanoparticles, wherein the noble metal nanoparticles comprise one or more of gold nanobipyramids, gold nanowires, gold nanospheres or silver nanowires; the hexadecyltrimethylammonium chloride and the noble metal nanoparticles are uniformly distributed in the PEDOT:PSS, and the total weight of the hexadecyltrimethylammonium chloride and the noble metal nanoparticles does not exceed 8% of the PEDOT:PSS.

2. The solid aluminum electrolytic capacitor according to claim 1, characterized in that: The weight of the hexadecyltrimethylammonium chloride is 1%-5% of the weight of PEDOT:PSS.

3. The solid aluminum electrolytic capacitor according to claim 1, characterized in that: The weight of the noble metal nanoparticles is 1%-5% of the weight of PEDOT:PSS.

4. A method for preparing a solid aluminum electrolytic capacitor, characterized in that: The steps include: 1) Add the precious metal nanoparticles into the hexadecyltrimethylammonium chloride solution and stir evenly; set aside; 2) adding the hexadecyltrimethylammonium chloride solution mixed with the noble metal nanoparticles to the PEDOT:PSS dispersion, stirring evenly to form a ternary mixed solution; and setting aside; the total weight of the hexadecyltrimethylammonium chloride and the noble metal nanoparticles does not exceed 8% of the PEDOT:PSS; 3) Dry the core package at 45-120℃; 4) The core bag is impregnated with the ternary mixed solution of step 2), and the core bag is dried at a temperature of room temperature to 80°C; 5) The core package is sealed and arranged in the housing.

5. The method for preparing a solid aluminum electrolytic capacitor according to claim 4, characterized in that: In the PEDOT:PSS dispersion, the weight percentage of PEDOT:PSS is 1%-8%.

6. The method for preparing a solid aluminum electrolytic capacitor according to claim 4, characterized in that: The solvent of the hexadecyltrimethylammonium chloride solution in step 1) is the same as the solvent of the PEDOT:PSS dispersion in step 2).

7. The method for preparing a solid aluminum electrolytic capacitor according to claim 4, characterized in that: In the step 4), the core package is first impregnated with the solvent of the PEDOT:PSS dispersion before being impregnated with the ternary mixed solution.

8. The method for preparing a solid aluminum electrolytic capacitor according to claim 4, characterized in that: After step 4) is completed, the core contains electrolyte.