阅读说明：本技术 一种降低导电聚合物固体铝电解电容器阻抗和损耗的方法 (Method for reducing impedance and loss of conductive polymer solid aluminum electrolytic capacitor ) 是由 宋晔 王相元 罗志旗 金志平 周峰 于 2020-10-13 设计创作，主要内容包括：本发明公开了一种降低导电聚合物固体铝电解电容器高频阻抗和损耗的方法,利用磷酸二氢铵和乙二醇高温反应得到的溶液,浸泡附有导电聚合物的电容器芯子,然后进行热处理,由于经过这种溶液热处理后可提高导电聚合物的电导率,从而减小了电容器的高频阻抗和损耗,与未用这种溶液处理过的电容器相比,高频阻抗和损耗大幅下降,同时这种方法还能简化电容器制备工艺。本发明所述方法工艺步骤简单,原料易得,处理成本低。(The invention discloses a method for reducing high-frequency impedance and loss of a conductive polymer solid aluminum electrolytic capacitor, which comprises the steps of soaking a capacitor core attached with a conductive polymer by using a solution obtained by high-temperature reaction of ammonium dihydrogen phosphate and ethylene glycol, and then carrying out heat treatment. The method has the advantages of simple process steps, easily obtained raw materials and low treatment cost.)

1. A method for reducing impedance and loss of a conductive polymer solid aluminum electrolytic capacitor is characterized in that: the method comprises the following steps: soaking the capacitor core attached with the conductive polymer film in a solution obtained by high-temperature reaction of ammonium dihydrogen phosphate and ethylene glycol for a certain time under negative pressure, taking out and aging the capacitor core, wherein the soaking time is 15-25 min; and then carrying out heat treatment on the aged capacitor core until the capacitor core is dried.

2. The method of reducing impedance and loss of a conductive polymer solid aluminum electrolytic capacitor of claim 1, wherein: the capacitor core is formed by winding high specific volume low voltage energized anode aluminum foil, high specific volume cathode foil and electrolytic paper.

3. The method of reducing impedance and loss of a conductive polymer solid aluminum electrolytic capacitor of claim 1, wherein: the capacitor core attached with the conductive polymer film is prepared by the following steps: soaking the capacitor core into the conductive polymer dispersion liquid for 10-20 min under negative pressure; and drying the capacitor core after the impregnation treatment to obtain the capacitor core attached with the conductive polymer film.

4. The method of reducing impedance and loss of a conductive polymer solid aluminum electrolytic capacitor of claim 3, wherein: the conductive polymer dispersion is PEDOT: aqueous PSS dispersion or trichloromethane dispersion of polyaniline.

5. The method of reducing impedance and loss of a conductive polymer solid aluminum electrolytic capacitor of claim 1, wherein: the high-temperature reaction conditions of the ammonium dihydrogen phosphate and the ethylene glycol are as follows: 20.6g of ammonium dihydrogen phosphate and 200mL of glycol are put into a 250mL conical flask, heated to 180 ℃ under the stirring of magnetons, and reacted for one and half hours under the heat preservation; the reaction product was a clear, clear yellow solution, noted as ADP-EG solution.

6. The method of reducing impedance and loss of a conductive polymer solid aluminum electrolytic capacitor of claim 5, wherein: the aging treatment refers to electrifying the capacitor core soaked by ADP-EG at the normal temperature under the voltage of 29V for 1 h.

7. The method of reducing impedance and loss of a conductive polymer solid aluminum electrolytic capacitor of claim 1, wherein: the heat treatment temperature is 120-200 ℃.

Technical Field

The invention relates to the technical field of aluminum electrolytic capacitors, in particular to a method for reducing impedance and loss of a conductive polymer solid aluminum electrolytic capacitor.

Background

In the traditional liquid aluminum electrolytic capacitor, because the ionic conductive electrolyte solution is used as a cathode for leading out, the resistivity of a capacitor leading-out system is higher, so that the equivalent series resistance of the capacitor is larger and the loss is higher. The conductivity of the conductive polymer material is 2-3 orders of magnitude higher than that of the electrolyte because the conductive polymer material is an electronic conductor, and the conductivity is less affected by temperature. For example, poly 3, 4-ethylenedioxythiophene (PEDOT) is a commonly used conductive polymer material, and has the advantages of high conductivity, good thermal stability, easy use of being prepared into a stable aqueous dispersion, and the like, so that the poly 3, 4-ethylenedioxythiophene (PEDOT) can be used as a cathode lead-out material of a solid aluminum electrolytic capacitor to replace an electrolyte. The solid aluminum electrolytic capacitor made of the conductive polymer can continuously and normally work in a high-temperature environment, the dangerous conditions of leakage, deformation of a capacitor shell and even bursting of the traditional liquid aluminum electrolytic capacitor caused by heated vaporization of electrolyte can be avoided, and the safety and the reliability are greatly improved. At present, the conductive polymer solid aluminum electrolytic capacitor has important application value in high-speed and high-frequency electronic circuits.

The mainstream process for manufacturing the conductive polymer solid aluminum electrolytic capacitor at present is as follows: firstly, preparing a conductive polymer dispersion liquid, then immersing the capacitor core into the conductive polymer dispersion liquid, and removing the solvent through high-temperature drying to form a solid conductive polymer film between the oxide film and the cathode foil, thereby obtaining the conductive polymer solid aluminum electrolytic capacitor. For example, conductive polymers PEDOT are combined with PSS (polystyrene sulfonic acid) to formulate a uniform concentration of PEDOT: PSS aqueous dispersion, direct immersion of capacitor core in PEDOT: and drying the PSS aqueous dispersion at high temperature to remove water, and then forming a solid PEDOT film without impurities between the oxide film and the cathode foil, thereby obtaining the PEDOT solid aluminum electrolytic capacitor. But was measured by PEDOT: direct drying of aqueous dispersions of PSS produces PEDOT solid films with conductivities typically lower by about 10S/cm, which is quite different from the reported conductivities of PEDOT films (4380S/cm) (N.Kim et al, adv.Mater.2014,26, 2268-2272). Therefore, the equivalent series resistance value of the PEDOT solid aluminum electrolytic capacitor prepared by the process is still larger, and the reduction of high-frequency impedance and loss is not ideal. Similar is true for other conductive polymers such as polyaniline. How to further improve the conductivity of the conductive polymer solid film and further improve the high-frequency performance of the conductive polymer solid aluminum electrolytic capacitor is a problem which needs to be solved urgently.

Disclosure of Invention

The invention aims to provide a simple method for reducing high-frequency impedance and loss of a conductive polymer solid aluminum electrolytic capacitor. By adopting the method, the solution soaking heat treatment of the capacitor core is added by one step on the basis of the conventional preparation process of the conductive polymer solid aluminum electrolytic capacitor, and the secondary doping effect of the solution on the conductive polymer is utilized to improve the conductivity of the conductive polymer solid aluminum electrolytic capacitor, so that the conductive polymer solid aluminum electrolytic capacitor with lower high-frequency impedance and loss is obtained, and the application of the conductive polymer solid aluminum electrolytic capacitor in high-frequency electronic circuits is better met.

In order to solve the technical problems, the invention adopts the technical scheme that:

a method for reducing impedance and loss of a conductive polymer solid aluminum electrolytic capacitor comprises the following steps: soaking the capacitor core attached with the conductive polymer film in a solution obtained by high-temperature reaction of ammonium dihydrogen phosphate and ethylene glycol for a certain time under negative pressure, taking out and aging the capacitor core, wherein the soaking time is 15-25 min; and then carrying out heat treatment on the aged capacitor core until the capacitor core is dried.

Preferably, the capacitor core is formed by winding high specific volume low voltage energized anode aluminum foil, high specific volume cathode foil and electrolytic paper.

Specifically, a capacitor core attached with a conductive polymer film is prepared by the steps of: and (2) soaking the capacitor core into a conductive polymer dispersion liquid for 10-20 min under negative pressure, wherein the conductive polymer dispersion liquid is PEDOT: (ii) aqueous PSS dispersion or trichloromethane dispersion of polyaniline; and drying the capacitor core after the impregnation treatment to obtain the capacitor core attached with the conductive polymer film.

Specifically, the high-temperature reaction conditions of ammonium dihydrogen phosphate and ethylene glycol are as follows: 20.6g of ammonium dihydrogen phosphate and 200mL of glycol are put into a 250mL conical flask, heated to 180 ℃ under the stirring of magnetons, and reacted for one and half hours under the heat preservation; the reaction product was a clear, clear yellow solution, noted as ADP-EG solution.

Specifically, the aging treatment refers to electrifying the capacitor core soaked by ADP-EG at the normal temperature under the voltage of 29V for 1 h.

Preferably, the heat treatment temperature is 120 ℃ to 200 ℃.

Compared with the prior art, the method for reducing the impedance and the loss of the conductive polymer solid aluminum electrolytic capacitor has the following beneficial effects:

1. the high-frequency impedance and the loss of the capacitor obtained after the ADP-EG solution heat treatment are greatly reduced, and the electrical performance and the application range of the solid aluminum electrolytic capacitor are greatly improved and expanded;

2. the ADP-EG solution also has the function of repairing an aluminum oxide dielectric film, can be used for carrying out capacitor aging treatment before the conductive polymer film is subjected to heat treatment, does not need special aging pretreatment process steps, and optimizes the preparation process of the solid capacitor;

3. because the ADP-EG solution has certain dissolving capacity for the conductive polymer, the conductive polymer film can be more uniformly distributed on the aluminum foil and the electrolyte paper through the ADP-EG solution soaking treatment, thereby reducing the impregnation times of the conductive polymer dispersion liquid and simplifying the preparation process of the solid capacitor.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below.

Comparative example 1

Soaking a capacitor core with the specification of 25V and 1000 muF in 5 wt% of ammonium adipate electrolyte for 30min under a vacuum condition, taking out, and then electrifying and aging at the normal temperature of 29V for 1h to repair an oxide film; drying the aged and pretreated capacitor core in a 120 ℃ blast drying oven for 10min, and then drying in a 90 ℃ vacuum oven for 10 min; soaking the dried core in PEDOT (PSS) dispersion liquid with the solid content of 16% for 20min under the vacuum condition; taking out the core, drying in a blast drying oven at 120 ℃ for 10min, and then drying in a vacuum oven at 90 ℃ for 10 min; impregnating the primary dispersion liquid under the same condition and drying to obtain a capacitor core attached with PEDOT; and finally, packaging the capacitor core and carrying out power-on aging treatment for 1h at the temperature of 90 ℃ at 29V to obtain the PEDOT conducting polymer solid aluminum electrolytic capacitor.

Comparative example 2

Soaking a capacitor core with the specification of 25V and 1000 muF in 5 wt% of ammonium adipate electrolyte for 30min under a vacuum condition, taking out, and then electrifying and aging at the normal temperature of 29V for 1h to repair an oxide film; drying the aged and pretreated capacitor core in a 120 ℃ blast drying oven for 10min, and then drying in a 90 ℃ vacuum oven for 10 min; soaking the dried core in polyaniline chloroform dispersion liquid with solid content of 12% for 10min under vacuum condition; taking out the core, drying in a blast drying oven at 120 ℃ for 5min, and then drying in a vacuum oven at 90 ℃ for 5 min; impregnating the dispersion liquid twice under the same condition and drying to obtain a capacitor core attached with polyaniline; and finally, packaging the capacitor core and carrying out power-on aging treatment for 1h at the temperature of 90 ℃ at 29V to obtain the polyaniline conducting polymer solid aluminum electrolytic capacitor.

Example 1

Without an aging pretreatment process, putting a capacitor core with the specification of 25V and 1000 muF into PEDOT (PSS) dispersion with the solid content of 16% for soaking for 20min under a vacuum condition; taking out the core, drying in a blast drying oven at 120 ℃ for 10min, and then drying in a vacuum oven at 90 ℃ for 10 min; under the vacuum condition, putting the dried capacitor core into ADP-EG solution for impregnation for 20min, taking out and then carrying out aging treatment: namely electrifying for 1h at the normal temperature under the voltage of 29V; then carrying out heat treatment on the aged capacitor core until the capacitor core is dried, wherein the heat treatment temperature is 120 ℃; and finally, packaging the capacitor core and carrying out power-on aging treatment for 1h at the temperature of 90 ℃ at 29V to obtain the PEDOT conducting polymer solid aluminum electrolytic capacitor.

Example 2

Without an aging pretreatment process, putting a capacitor core with the specification of 25V and 1000 muF into polyaniline chloroform dispersion liquid with the solid content of 12% to soak for 10min under a vacuum condition; taking out the core, drying in a blast drying oven at 120 ℃ for 5min, and then drying in a vacuum oven at 90 ℃ for 5 min; under the vacuum condition, putting the dried capacitor core into ADP-EG solution for impregnation for 20min, taking out and then carrying out aging treatment: namely electrifying for 1h at the normal temperature under the voltage of 29V; then carrying out heat treatment on the aged capacitor core until the capacitor core is dried, wherein the heat treatment temperature is 120 ℃; and finally, packaging the capacitor core and carrying out power-on aging treatment for 1h at the temperature of 90 ℃ at 29V to obtain the polyaniline conducting polymer solid aluminum electrolytic capacitor.

Example 3

The preparation process of the solid aluminum electrolytic capacitor of conductive polymer was the same as that of example 1 except that the heat treatment temperature of the capacitor core after impregnation with ADP-EG solution was 140 ℃.

Example 4

The preparation process of the solid aluminum electrolytic capacitor of conductive polymer was the same as that of example 2 except that the heat treatment temperature of the capacitor core after impregnation with ADP-EG solution was 140 ℃.

Example 5

The preparation process of the conductive polymer solid aluminum electrolytic capacitor was the same as that of example 1 except that the heat treatment temperature of the capacitor core after impregnation with the ADP-EG solution was 160 ℃.

Example 6

The preparation process of the conductive polymer solid aluminum electrolytic capacitor was the same as that of example 2 except that the heat treatment temperature of the capacitor core after impregnation with the ADP-EG solution was 160 ℃.

Example 7

The preparation process of the solid aluminum electrolytic capacitor of conductive polymer was the same as that of example 1 except that the heat treatment temperature of the capacitor core after impregnation with ADP-EG solution was 180 ℃.

Example 8

The preparation process of the solid aluminum electrolytic capacitor of conductive polymer was the same as that of example 2 except that the heat treatment temperature of the capacitor core after impregnation with ADP-EG solution was 180 ℃.

Example 9

The preparation process of the conductive polymer solid aluminum electrolytic capacitor was the same as that of example 1 except that the heat treatment temperature of the capacitor core after impregnation with the ADP-EG solution was 200 ℃.

Example 10

The preparation process of the conductive polymer solid aluminum electrolytic capacitor was the same as that of example 2 except that the heat treatment temperature of the capacitor core after impregnation with the ADP-EG solution was 200 ℃.

The main properties of the above examples and comparative examples are compared in table 1 below:

as can be seen from the data in the table, both the capacitors prepared from the PEDOT/PSS dispersion liquid and the capacitors prepared from the polyaniline/trichloromethane dispersion liquid can obviously reduce the high-frequency impedance and the loss of the conductive polymer solid aluminum electrolytic capacitor after the ADP-EG solution is adopted for heat treatment.

The present invention is not limited to the embodiments described above, and those skilled in the art may make modifications or changes within the scope of the disclosure without departing from the spirit of the present invention, so that the scope of the present invention is defined by the appended claims.