A solid aluminum electrolytic capacitor for automobiles and a preparation method thereof

Abstract

A solid aluminum electrolytic capacitor for automobiles, comprising a housing and a core package. The core package is sealed inside the housing and is formed by winding or laminating an anode foil, electrolytic paper, and a cathode foil. A conductive polymer is formed between the anode foil and the cathode foil. The conductive polymer includes a PEDOT:PSS film compounded with hydroxyethyl cellulose, and the hydroxyethyl cellulose is hydroxyethyl cellulose skeletal particles with a size of less than 50 microns. In the present invention, the PEDOT:PSS compounded with hydroxyethyl cellulose with a size of less than 50 microns can effectively improve the mechanical properties, service cycle life, and vibration resistance of the solid aluminum electrolytic capacitor.

Description

Technical Field

[0001] The present invention relates to a solid aluminum electrolytic capacitor, and more particularly to a solid aluminum electrolytic capacitor suitable for automotive use, which has good stability and excellent mechanical properties. Background Art

[0002] Nowadays, the development of electric vehicles is very rapid. The intelligence, networking, and deep electronization of electric vehicles have made them increasingly popular in the market. It is believed that electric vehicles will become the mainstream of automobiles in the near future. However, the automotive electronics field is different from the general consumer electronics field, especially in terms of safety performance, where the requirements are extremely strict. This has led to the fact that in the process of using solid aluminum electrolytic capacitors in electronics, the stability of solid aluminum electrolytic capacitors ranks first. At the same time, the vibration generated by electronic products during the operation of the vehicle makes it difficult for general products to be applicable. Specifically, for solid aluminum electrolytic capacitors, it is manifested as the requirement for the mechanical properties of solid aluminum electrolytic capacitors. Currently, general solid aluminum electrolytic capacitors cannot meet the requirements of the automotive electronics field in terms of mechanical stability. 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 for automotive use with good mechanical stability and its preparation method.

[0004] To solve the above technical problem, the technical solution proposed by the present invention is: A solid aluminum electrolytic capacitor for automotive use, comprising a housing and a core package. The core package is hermetically disposed within the housing. The core package is formed by winding or laminating an anode foil, electrolytic paper, and a cathode foil. A conductive polymer is formed between the anode foil and the cathode foil. The conductive polymer includes a hydroxyethyl cellulose-doped PEDOT:PSS film, and the hydroxyethyl cellulose is hydroxyethyl cellulose skeletal particles with a size of less than 50 microns.

[0005] For the above-mentioned solid aluminum electrolytic capacitor for automotive use, preferably, the hydroxyethyl cellulose particles are treated with sulfamic acid.

[0006] A preparation method of a solid aluminum electrolytic capacitor for automotive use, comprising the following steps;

[0007] 1) Prepare hydroxyethyl cellulose particles with a size of less than 50 microns;

[0008] 2) Add the hydroxyethyl cellulose particles prepared in step 1) to the PEDOT:PSS dispersion liquid and disperse evenly;

[0009] 3) Immerse the core package in the PEDOT:PSS dispersion liquid prepared in step 2) and dry it; so as to form a PEDOT:PSS film within the core package.

[0010] For the preparation method of the above-mentioned solid aluminum electrolytic capacitor for automobiles, preferably, the hydroxyethyl cellulose particles in step 1) are treated by soaking in sulfamic acid, and the weight concentration of the sulfamic acid is 2 g / L - 10 g / L.

[0011] For the preparation method of the above-mentioned solid aluminum electrolytic capacitor for automobiles, preferably, the preparation method of step 1) includes the following steps: ① Completely dissolve 1 - 5 parts by weight of hydroxyethyl cellulose in 100 - 200 parts by weight of deionized water, and stir evenly; ② Add 1 - 5 parts by weight of glycerol, stir evenly, and filter impurities; ③ Dry the filtrate to obtain a hydroxyethyl cellulose film; ④ Put the hydroxyethyl cellulose film obtained in step ③ into a homogenizer to obtain hydroxyethyl cellulose particles; After filtration, hydroxyethyl cellulose particles with a size of less than 50 microns are obtained.

[0012] For the preparation method of the above-mentioned solid aluminum electrolytic capacitor for automobiles, preferably, a surfactant is added to the PEDOT:PSS dispersion in step 2).

[0013] For the preparation method of the above-mentioned solid aluminum electrolytic capacitor for automobiles, preferably, after step 3) is completed, annealing is carried out at a temperature of 60 - 100 °C for 15 - 30 minutes.

[0014] Compared with the prior art, the advantages of the present invention are as follows: In the present invention, PEDOT:PSS composite with hydroxyethyl cellulose of less than 50 microns can effectively improve the mechanical properties, service life and vibration resistance of the solid aluminum electrolytic capacitor. Detailed implementation manners

[0015] For the convenience of understanding the present invention, the following will describe the present invention more comprehensively and meticulously in combination with preferred embodiments, but the protection scope of the present invention is not limited to the following specific embodiments.

[0016] It should be particularly noted that when a certain element is described as "fixed to, fixedly connected to, connected to or communicated with" another element, it can be directly fixed, fixedly connected, connected or communicated to the other element, or indirectly fixed, fixedly connected, connected or communicated to the other element through other intermediate connectors.

[0017] Unless otherwise defined, all professional terms used hereinafter have the same meaning as commonly 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 protection scope of the present invention. Example 1

[0018] A solid aluminum electrolytic capacitor for automobiles, comprising a housing and a core package. The core package is hermetically arranged in the housing through a rubber plug. The core package is formed by winding or laminating an anode foil, electrolytic paper, and a cathode foil. A conductive polymer is formed between the anode foil and the cathode foil. The conductive polymer includes a PEDOT:PSS film compounded with hydroxyethyl cellulose, and the hydroxyethyl cellulose is hydroxyethyl cellulose skeleton particles with a size of less than 50 microns. The hydroxyethyl cellulose particles are treated by soaking in sulfamic acid.

[0019] A preparation method of the solid aluminum electrolytic capacitor for automobiles in this embodiment includes the following steps;

[0020] 1) Prepare hydroxyethyl cellulose particles with a size of less than 50 microns;

[0021] 2) Add the hydroxyethyl cellulose particles prepared in step 1) to the PEDOT:PSS dispersion liquid and disperse evenly. A surfactant can be added to the PEDOT:PSS dispersion liquid in step 2). In this embodiment, the surfactant can be an aliphatic sulfonate, an alkyl aryl sulfonate, and an alkyl naphthalene sulfonate. The weight concentration of the surfactant is 0.5%.

[0022] 3) The core package is impregnated with the PEDOT:PSS dispersion liquid prepared in step 2) and then dried; so that a PEDOT:PSS film is formed in the core package. In order to increase the amount of PEDOT:PSS impregnated into the core package, the PEDOT:PSS dispersion liquid prepared in step 2) can be impregnated 2 - 5 times repeatedly. After step 3) is completed, annealing is carried out at a temperature of 60 - 100 °C for 15 - 30 minutes.

[0023] The hydroxyethyl cellulose particles in step 1) are treated by soaking in sulfamic acid, and the soaking temperature is room temperature - 80 °C; the concentration of sulfamic acid is 4 g / L. Also, according to actual needs, the concentration of sulfamic acid can be selected between 2 g / L - 10 g / L. In this embodiment, when the hydroxyethyl cellulose skeleton particles with a size of less than 50 microns are treated by soaking in sulfamic acid, the -OH functional groups on the surface of the hydroxyethyl cellulose skeleton particles are coupled with the amine group and sulfonic acid group of sulfamic acid. In addition, the positively charged PEDOT combines with the amine group and sulfonic acid group of sulfamic acid to form stronger S-N bonds and S-O bonds respectively. Under the action of sulfamic acid, the surface functionalization of the hydroxyethyl cellulose skeleton particles is enhanced, so that the bonding between PEDOT:PSS and the hydroxyethyl cellulose skeleton particles is effectively improved, thereby enabling effective compounding between PEDOT:PSS and the hydroxyethyl cellulose skeleton particles; thus, the flexibility of the PEDOT:PSS film is enhanced, that is, the mechanical stability of the solid aluminum electrolytic capacitor is enhanced.

[0024] In this embodiment, the preparation method of step 1) includes the following steps: ① Completely dissolve 1-5 parts by weight of hydroxyethyl cellulose in 100-200 parts by weight of deionized water, and stir evenly; ② Add 1-5 parts by weight of glycerol, stir evenly, and filter impurities; ③ Bake the filtrate to obtain a hydroxyethyl cellulose film; ④ Put the hydroxyethyl cellulose film obtained in step ③ into a homogenizer to obtain hydroxyethyl cellulose particles; After filtration, hydroxyethyl cellulose particles with a size of less than 50 microns are obtained.

[0025] A surfactant is added to the PEDOT:PSS dispersion in step 2).

[0026] In this embodiment, although the amount of hydroxyethyl cellulose compounded in the PEDOT:PSS film is very small, it will still affect the conductivity of the PEDOT:PSS film to a certain extent. Coupled with the fact that the conductivity of the PEDOT:PSS film itself is relatively high, this results in a relatively high internal resistance of the prepared aluminum electrolytic capacitor. In this embodiment, after step 3) is completed, the core can be impregnated with aminosulfonic acid with a weight concentration of 2 g / L - 10 g / L to post-treat the PEDOT:PSS in the core package. It can remove part of the PSS and hydroxyethyl cellulose on the film surface, and at the same time transform the PEDOT structure from a curly structure to a linear structure, thereby improving the conductivity. However, this treatment may damage the oxide film on the surface of the anode foil. Therefore, after the treatment is completed, the core package needs to be impregnated with a small amount of electrolyte to repair the anode foil; after repairing with the electrolyte, the core package can be heated at a temperature below 80 °C to volatilize the electrolyte.

[0027] In the present invention, PEDOT:PSS compounded with hydroxyethyl cellulose below fifty microns can effectively improve the mechanical properties, service cycle life and vibration resistance of solid aluminum electrolytic capacitors; it is suitable for use in the field of automotive electronics.

[0028] Comparative Example 1

[0029] In this embodiment, the PEDOT:PSS film is not compounded with hydroxyethyl cellulose and no aminosulfonic acid treatment is carried out. Other parts are the same as in Example 1.

[0030] Comparative Example 2

[0031] In this embodiment, hydroxyethyl cellulose is compounded in the PEDOT:PSS film, and the treatment method is the same as in Example 1, but no aminosulfonic acid treatment is carried out. Other parts are the same as in Example 1.

[0032] Prepare 20 products of Example 1, Comparative Example 1 and Comparative Example 2 respectively; measure their capacitances, average internal resistances and average capacitance retention rates after 10,000 surge tests respectively. At the same time, select products of Example 1, Comparative Example 1 and Comparative Example 2 with the same parameters for vibration experiments. The parameters of the products are as follows: 48V, 470 μF.

[0033] Table 1 shows the average capacitances, average ESRs and average capacitance retention rates of the products of Example 1, Comparative Example 1 and Comparative Example 2.

[0034] 。

[0035] The method of the vibration experiment is as follows. Install the solid aluminum electrolytic capacitor on the circuit board, and then place the whole circuit board into the vibrating tray for vibration. The vibration frequency is 10Hz - 50Hz - 10Hz, and the interval time is 1 min; the amplitude is 0.75 mm; the vibration directions are the X, Y, and Z axes, 2 hours / axis. After the vibration is completed, measure the capacitance and internal resistance of the solid aluminum electrolytic capacitor within 30 min.

[0036] Table 2 shows the average capacitances and average internal resistances of the products of Example 1, Comparative Example 1 and Comparative Example 2 after the vibration experiment.

[0037] 。

Claims

1. A solid aluminum electrolytic capacitor for automobiles, comprising a housing and a core package. The core package is hermetically arranged inside the housing. The core package is formed by winding or laminating an anode foil, electrolytic paper, and a cathode foil. It is characterized in that: A conductive polymer is formed between the anode foil and the cathode foil, and the conductive polymer includes a PEDOT:PSS film composite with hydroxyethyl cellulose. The hydroxyethyl cellulose is hydroxyethyl cellulose framework particles with a size of less than 50 microns; the hydroxyethyl cellulose particles are treated with sulfamic acid.

2. A method for preparing a solid aluminum electrolytic capacitor for an automobile as described in claim 1, characterized in that: It includes the following steps; 1) Prepare hydroxyethyl cellulose particles with a size of less than 50 microns; 2) Add the hydroxyethyl cellulose particles prepared in step 1) into the PEDOT:PSS dispersion and disperse evenly; 3) The core contains the PEDOT:PSS dispersion prepared in step 2) and is dried; so that a PEDOT:PSS film is formed in the core package.

3. The preparation method of the solid aluminum electrolytic capacitor for automobiles according to claim 2, characterized in that: The hydroxyethyl cellulose particles in step 1) are soaked and treated with sulfamic acid, and the weight concentration of the sulfamic acid is 2 g / L - 10 g / L.

4. The preparation method of the solid aluminum electrolytic capacitor for automobiles according to claim 2, characterized in that: The preparation method of step 1) includes the following steps: ① Completely dissolve 1 - 5 parts by weight of hydroxyethyl cellulose in 100 - 200 parts by weight of deionized water and stir evenly; ② Add 1 - 5 parts by weight of glycerol, stir evenly and filter impurities; ③ Bake the filtrate to obtain a hydroxyethyl cellulose film; ④ Put the hydroxyethyl cellulose film obtained in step ③ into a homogenizer to obtain hydroxyethyl cellulose particles; hydroxyethyl cellulose particles with a size of less than 50 microns are obtained after filtration.

5. The preparation method of the solid aluminum electrolytic capacitor for automobiles according to claim 2, wherein: A surfactant is added to the PEDOT:PSS dispersion in step 2).

6. The preparation method of the solid aluminum electrolytic capacitor for automobiles according to claim 2, characterized in that: After step 3) is completed, annealing is carried out at a temperature of 60 - 100 °C for 15 - 30 minutes.