High self-healing metallized film and capacitor

Abstract

The invention relates to a high self-healing metallized film and a capacitor, the high self-healing metallized film comprises a capacitor core, after the high self-healing metallized film is wound into a roll core, metal spraying is performed on two ends of the roll core to obtain the capacitor core; and feeding the insulating film into a silane coupling agent solution, and carrying out surface modification treatment under the action of a liquid-electric effect to obtain the silane modified insulating film. The silane coupling agent is utilized to modify the insulating film under the action of a liquid-electric effect, so that the interface performance of the silane modified insulating film is remarkably improved, the bonding strength between the aluminum-plated layer and the silane modified insulating film is enhanced, and even if the aluminum-plated layer in a local area is deposited again after self-healing, the aluminum-plated layer is not only easy to be bonded with the silane modified insulating film, but also easy to be bonded with the silane modified insulating film. Meanwhile, the silane modified insulating film is not easy to break down, the initial self-healing breakdown field strength of the film capacitor is remarkably improved, even if self-healing occurs, the maximum self-healing hole area is remarkably reduced, and the self-healing performance of the film capacitor is excellent.

Description

Technical Field

[0001] The present invention and the field of film capacitors specifically relate to a highly self-healing metallized film and capacitor. Background Art

[0002] Film capacitors are also called plastic film capacitors, which use plastic film as dielectric.

[0003] The structure of an existing film capacitor generally includes a capacitor housing, a capacitor core, and electrodes electrically connected to the capacitor core. After the metallized film is wound into a core, gold is sprayed on both ends of the core to obtain the capacitor core. The metallized film is obtained by forming an aluminum layer on the surface of the insulating film through a vacuum aluminum plating process.

[0004] As the use environment of film capacitors becomes more and more harsh, especially in some harsh outdoor environments, highly self-healing film capacitors are needed.

[0005] The reason why film capacitors can self-heal is mainly because of their internal structure and material characteristics that enable them to self-heal. The following are the main reasons why film capacitors can self-heal:

[0006] 1. Self-healing materials: Film capacitors usually use materials with self-healing properties, such as polypropylene film, etc. These materials can automatically form a local insulation layer or restore the broken dielectric when they are broken down or partially broken down by external voltage, thereby preventing the capacitor from completely failing due to breakdown.

[0007] 2. Internal structure design: The structural design of film capacitors enables them to limit the damage extension when they are broken down or partially damaged, and form a self-healing effect in the damaged area. For example, the structure of the capacitor may include multiple tiny electrodes separated by thin films, and these films can repair damage by themselves.

[0008] 3. Energy release: When a film capacitor breaks down, local high temperature and high pressure are usually generated, which may cause local melting or vaporization of the material. Subsequently, the material re-solidifies and forms an insulating layer, which helps to prevent the further expansion of the breakdown.

[0009] From the above, we can see that the self-healing performance of film capacitors depends largely on the performance of the insulating film. If a complex metal plating pattern is designed, although the self-healing performance can be significantly improved, it will make the coating process complicated, thereby significantly increasing the processing cost.

[0010] Based on this, the present invention is proposed. Summary of the invention

[0011] The specific technical solutions of the present invention are as follows:

[0012] A high self-healing capacitor comprises a capacitor housing, a capacitor core, and an electrode electrically connected to the capacitor core. The preparation method of the capacitor core comprises the following steps:

[0013] After the highly self-healing metallized film is wound into a winding core, gold is sprayed on both ends of the winding core to obtain the capacitor core; the preparation method of the highly self-healing metallized film comprises the following steps:

[0014] The insulating film is placed in a silane coupling agent solution, and the surface is modified under the action of the liquid-electric effect to obtain a silane-modified insulating film;

[0015] The highly self-healing metallized film is obtained by forming an aluminum layer on the surface of the silane-modified insulating film through a vacuum aluminum plating process using a physical vapor deposition method.

[0016] In an optional embodiment, the insulating film is one or more of a polyethylene film, a polypropylene film, and a polycarbonate film.

[0017] In an optional embodiment, the silane coupling agent solution is prepared by dissolving a silane coupling agent in an organic solvent.

[0018] In an optional embodiment, the organic solvent is one or more of an alcohol solvent, a ketone solvent, an ester solvent, and a hydrocarbon solvent.

[0019] In an optional embodiment, the mass fraction of the silane coupling agent in the silane coupling agent solution is 3.5% to 5%.

[0020] In an optional embodiment, the organic solvent is butanone.

[0021] In an optional embodiment, the insulating film and the silane coupling agent solution are placed in a liquid battery, a liquid-electric effect occurs in the liquid battery, and two electrodes connected to the liquid battery are externally connected to a pulse power supply. The pulse voltage of the pulse power supply is 8000-10000V, the frequency is 25-30Hz, and the pulse duty cycle is 12%.

[0022] In the present invention, the highly self-healing film capacitor modifies the existing insulating film and uses a silane coupling agent to modify the insulating film under the action of the liquid-electric effect, thereby significantly improving the interface performance of the silane-modified insulating film, and enhancing the bonding strength between the aluminum-plated layer and the silane-modified insulating film. Even if the aluminum-plated layer in a local area is re-deposited after self-healing, it is not only easy to combine with the silane-modified insulating film, but also the silane-modified insulating film is not easily broken down. The initial self-healing breakdown field strength of the film capacitor is significantly improved. Even if self-healing occurs, the maximum self-healing hole area is significantly reduced. The film capacitor has excellent self-healing performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a graph showing the change trend of the pulse duty cycle of the pulse power supply and the maximum self-healing hole area in Example 7. DETAILED DESCRIPTION

[0024] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments.

[0025] Example 1

[0026] A highly self-healing film capacitor comprises a capacitor housing, a capacitor core, and an electrode electrically connected to the capacitor core. The preparation method of the capacitor core comprises the following steps:

[0027] After the highly self-healing metallized film is wound into a winding core, gold is sprayed on both ends of the winding core to obtain the capacitor core; the preparation method of the highly self-healing metallized film comprises the following steps:

[0028] The insulating film is placed in a silane coupling agent solution, and the surface is modified under the action of the liquid-electric effect to obtain a silane-modified insulating film;

[0029] The highly self-healing metallized film is obtained by forming an aluminum layer on the surface of the silane-modified insulating film through a vacuum aluminum plating process using a physical vapor deposition method.

[0030] The insulating film is a polyethylene film.

[0031] The silane coupling agent solution is prepared by dissolving the silane coupling agent in an organic solvent.

[0032] The organic solvent is butanone. The mass fraction of the silane coupling agent in the silane coupling agent solution is 3.5%.

[0033] The insulating film and the silane coupling agent solution are placed in a liquid battery, and a liquid-electric effect reaction occurs in the liquid battery for 5 minutes. Two electrodes connected to the liquid battery are externally connected to a pulse power supply, and the pulse voltage of the pulse power supply is 8000V, the frequency is 25Hz, and the pulse duty cycle is 12%.

[0034] Example 2

[0035] A highly self-healing film capacitor comprises a capacitor housing, a capacitor core, and an electrode electrically connected to the capacitor core. The preparation method of the capacitor core comprises the following steps:

[0036] After the highly self-healing metallized film is wound into a winding core, gold is sprayed on both ends of the winding core to obtain the capacitor core; the preparation method of the highly self-healing metallized film comprises the following steps:

[0037] The insulating film is placed in a silane coupling agent solution, and the surface is modified under the action of the liquid-electric effect to obtain a silane-modified insulating film;

[0038] The highly self-healing metallized film is obtained by forming an aluminum layer on the surface of the silane-modified insulating film through a vacuum aluminum plating process using a physical vapor deposition method.

[0039] The insulating film is a polypropylene film.

[0040] The silane coupling agent solution is prepared by dissolving the silane coupling agent in an organic solvent.

[0041] The mass fraction of the silane coupling agent in the silane coupling agent solution is 4%.

[0042] The organic solvent is butanone.

[0043] The insulating film and the silane coupling agent solution are placed in a liquid battery, and a liquid-electric effect reaction occurs in the liquid battery for 5 minutes. Two electrodes connected to the liquid battery are externally connected to a pulse power supply, and the pulse voltage of the pulse power supply is 9000V, the frequency is 25Hz, and the pulse duty cycle is 12%.

[0044] Example 3

[0045] A highly self-healing film capacitor comprises a capacitor housing, a capacitor core, and an electrode electrically connected to the capacitor core. The preparation method of the capacitor core comprises the following steps:

[0046] After the highly self-healing metallized film is wound into a winding core, gold is sprayed on both ends of the winding core to obtain the capacitor core; the preparation method of the highly self-healing metallized film comprises the following steps:

[0047] The insulating film is placed in a silane coupling agent solution, and the surface is modified under the action of the liquid-electric effect to obtain a silane-modified insulating film;

[0048] The highly self-healing metallized film is obtained by forming an aluminum layer on the surface of the silane-modified insulating film through a vacuum aluminum plating process using a physical vapor deposition method.

[0049] The insulating film is a polycarbonate film.

[0050] The silane coupling agent solution is prepared by dissolving the silane coupling agent in an organic solvent.

[0051] The mass fraction of the silane coupling agent in the silane coupling agent solution is 5%.

[0052] The organic solvent is butanone.

[0053] The insulating film and the silane coupling agent solution are placed in a liquid battery, and a liquid-electric effect reaction occurs in the liquid battery for 5 minutes. Two electrodes connected to the liquid battery are externally connected to a pulse power supply, and the pulse voltage of the pulse power supply is 10000V, the frequency is 30Hz, and the pulse duty cycle is 12%.

[0054] Example 4

[0055] In this example, the insulating film is placed in a silane coupling agent solution and reacted in an ultrasonic cleaning tank at 20 kHz for 5 minutes for surface modification to obtain a control modified insulating film; the control modified insulating film is used to replace the silane modified insulating film in Example 1, and the rest is the same as Example 1.

[0056] Example 5

[0057] In this example, the silane-modified insulating film is replaced with an existing common polyethylene film, and the rest is the same as in Example 1.

[0058] Example 6

[0059] In this example, the insulating film is placed in butanone and subjected to surface modification treatment under the action of the hydroelectric effect to obtain a hydroelectric modified insulating film; the hydroelectric modified insulating film is used to replace the silane modified insulating film, and the rest is the same as Example 1.

[0060] Example 7

[0061] In this example, the difference from Example 1 is that the pulse duty cycle of the pulse power supply is changed, and the initial self-healing breakdown field strength fluctuates within the range of 185 to 200 V / μm, with little change; but the corresponding maximum self-healing hole area change trend is shown in FIG. Figure 1 .

[0062] Depend on Figure 1 It can be seen that, preferably, the pulse duty cycle of the pulse power supply is 12%.

[0063] 《Self-healing breakdown characterization test》

[0064] The capacitors used in the test are all double-sided metallized films with a thickness of 5μm, a square resistance of 3.9Ω / sq, a capacitance of 1.0μF+5%, and a rated voltage of 250V. During the test, the voltage of the capacitor was boosted to 2000V at a rate of 25V / s to study the initial self-healing breakdown field strength during the boosting process. The initial self-healing breakdown field strength refers to the field strength corresponding to the breakdown voltage when the first self-healing occurs, which is defined as the initial self-healing breakdown field strength; it is well known in the art that the larger the initial self-healing breakdown field strength, the smaller the maximum self-healing hole, indicating that the self-healing performance of the capacitor is better.

[0065] The test results of Examples 1 to 6 are shown in Table 1:

[0066] Table 1

[0067] Initial self-healing breakdown field strength (V / μm) <![CDATA[Maximum self-healing hole area (mm 2 )]]> Example 1 198.25 0.011 Example 2 190.17 0.009 Example 3 188.98 0.016 Example 4 175.29 0.288 Example 5 179.16 0.212 Example 6 180.02 0.203

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A highly self-healing metallized film, comprising an insulating film and an aluminum-plated layer, characterized in that: The insulating film is placed in a silane coupling agent solution, and the surface is modified under the action of the liquid-electric effect to obtain a silane-modified insulating film; The metallized film is obtained by forming an aluminum layer on the surface of the silane-modified insulating film through a vacuum aluminum plating process using a physical vapor deposition method.

2. The highly self-healing metallized film according to claim 1, characterized in that: The insulating film is one or more of a polyethylene film, a polypropylene film, and a polycarbonate film.

3. The highly self-healing metallized film according to claim 1, characterized in that: The silane coupling agent solution is prepared by dissolving the silane coupling agent in an organic solvent.

4. The highly self-healing metallized film according to claim 3, characterized in that: The organic solvent is one or more of an alcohol solvent, a ketone solvent, an ester solvent, and a hydrocarbon solvent.

5. The highly self-healing metallized film according to claim 3, characterized in that: The mass fraction of the silane coupling agent in the silane coupling agent solution is 3.5% to 5%.

6. The highly self-healing metallized film according to claim 4, characterized in that: The organic solvent is butanone.

7. The highly self-healing metallized film according to claim 1, characterized in that: The insulating film and the silane coupling agent solution are placed in a liquid battery, and a liquid-electric effect occurs in the liquid battery. Two electrodes connected to the liquid battery are externally connected to a pulse power supply, and the pulse voltage of the pulse power supply is 8000-10000V, the frequency is 25-30Hz, and the pulse duty cycle is 12%.

8. A highly self-healing capacitor, comprising a capacitor housing, a capacitor core, and an electrode electrically connected to the capacitor core, characterized in that: After the highly self-healing metallized film according to any one of claims 1 to 7 is wound into a winding core, gold is sprayed on both ends of the winding core to obtain the capacitor core.

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