A high performance metallized film capacitor

Abstract

The present application relates to a kind of high-performance metallized film capacitors, including epoxy resin encapsulation layer for completely wrapping capacitor core, epoxy resin encapsulation layer is high-performance epoxy resin adhesive in UV wavelength 360-420nm ultraviolet light normal temperature solidification is made, high-performance epoxy resin adhesive is made by epoxy resin adhesive, Bi2MoO6@ZIF-8@g-C3N4Mixing.The high-performance metallized film capacitor is replaced by Bi2MoO6@ZIF-8@g-C3N4 by adopting existing alumina and other fillers, it is incorporated into epoxy resin adhesive to make high-performance epoxy resin adhesive, the capacitor is packaged using the high-performance epoxy resin adhesive, can significantly improve the ablation-resistant fire performance of capacitor.

Description

Technical Field

[0001] The present invention relates to the field of high-performance metallized film capacitors, and in particular to high-performance metallized film capacitors. Background Art

[0002] Film capacitors, also known as plastic film capacitors, use plastic film as the dielectric.

[0003] The structure of existing film capacitors generally includes a capacitor case, a capacitor core, and an epoxy resin encapsulation layer that completely encapsulates the capacitor core. The epoxy resin encapsulation layer is generally made by curing epoxy resin adhesive doped with fillers (such as spherical aluminum oxide).

[0004] With the application of film capacitors in the field of new energy vehicles, if a localized fire occurs, capacitors are commonly used and widely used electronic components, and the requirements for their inherent fire resistance are becoming increasingly stringent. Generally, capacitors have a certain energy storage function. Therefore, if a breakdown explosion occurs in a high-temperature environment, at least one of the two pins of the capacitor will be instantly severed, thereby making the capacitor in an instantaneous disconnected state, making it less likely to cause a large-scale fire. However, in actual situations, the continuous burning of high-temperature flames often burns through the interior of the capacitor, causing serious internal fires, which intensifies the surrounding fire and easily leads to large-scale fires.

[0005] Based on this, the present invention is proposed. Summary of the Invention

[0006] The specific technical solutions of the present invention are as follows:

[0007] A high-performance metallized film capacitor includes a capacitor housing, a capacitor core located within the capacitor housing, and an epoxy resin encapsulation layer for completely encapsulating the capacitor core. The epoxy resin encapsulation layer is made of a high-performance epoxy resin adhesive that is cured at room temperature under ultraviolet light with a UV wavelength of 360-420nm. The high-performance epoxy resin adhesive is made by mixing epoxy resin adhesive and high-performance composite filler.

[0008] In an optional embodiment, the high-performance composite filler is Bi2MoO6@ZIF-8@g-C3N4.

[0009] In an optional embodiment, the preparation method of Bi2MoO6@ZIF-8@g-C3N4 comprises the following steps:

[0010] Step 1. Preparation of Bi2MoO6@ZIF-8

[0011] The metal organic framework material ZIF-8 and Bi2MoO6 are added into an alcohol solvent, mixed and stirred to disperse, and then sent into a reflux reactor. Nitrogen is filled to exhaust the air in the reflux reactor, and then refluxed for 12-24 h. After the reaction is completed, the product is centrifuged, washed with ethanol for several times, dried, and Bi2MoO6@ZIF-8 is obtained.

[0012] Step 2, preparation of Bi2MoO6@ZIF-8@g-C3N4

[0013] After Bi2MoO6@ZIF-8, g-C3N4 and an organic solvent are mixed and stirred uniformly, ultrasonic dispersion is performed for 5 min, and then megasonic dispersion is performed at 0℃ for 10-15 min. After filtration, the filter residue is dried and ground, and Bi2MoO6@ZIF-8@g-C3N4 is obtained.

[0014] In an alternative embodiment, in step 1, the mass ratio of the metal organic framework material ZIF-8 and Bi2MoO6 is (3-3.1):1.

[0015] In an alternative embodiment, in step 1, the alcohol solvent is one or more of methanol, ethanol, propanol and butanol.

[0016] In an alternative embodiment, in step 1, the mass-volume ratio of the metal organic framework material ZIF-8 and the alcohol solvent is 1:(300-400).

[0017] In an alternative embodiment, in step 2, the mass ratio of Bi2MoO6@ZIF-8 and g-C3N4 is 10:(1.1-1.3).

[0018] In an alternative embodiment, in step 2, the mass-volume ratio of Bi2MoO6@ZIF-8 and the organic solvent is 1:(20-25).

[0019] In an alternative embodiment, in step 2, the ultrasonic frequency during ultrasonic dispersion is 20 kHz, and the megasonic frequency during megasonic dispersion is 0.81 MHz.

[0020] In an alternative embodiment, in step 1, the drying temperature is 65-80℃.

[0021] In step 2, the filter residue drying temperature is 65-80℃.

[0022] In the application, the high-performance metalized thin film capacitor is prepared by replacing the existing filler such as alumina with Bi2MoO6@ZIF-8@g-C3N4, mixing the Bi2MoO6@ZIF-8@g-C3N4 into the epoxy resin adhesive to form a high-performance epoxy resin adhesive, and packaging the capacitor by using the high-performance epoxy resin adhesive, so that the ablation and fire resistance of the capacitor can be significantly improved. DETAILED DESCRIPTION

[0023] The application will be further explained and described below in combination with specific examples.

[0024] Example 1

[0025] A high-performance metalized thin film capacitor, comprising a capacitor shell, a capacitor core located in the capacitor shell, and an epoxy resin packaging layer for completely wrapping the capacitor core, wherein the epoxy resin packaging layer is prepared by curing a high-performance epoxy resin adhesive under UV wavelength 360-420 nm ultraviolet light at room temperature, and the high-performance epoxy resin adhesive is prepared by mixing an epoxy resin adhesive and a high-performance composite filler.

[0026] The high-performance composite filler is Bi2MoO6@ZIF-8@g-C3N4, and the mass ratio of Bi2MoO6@ZIF-8@g-C3N4 to the epoxy resin adhesive is 1:4.

[0027] Step 1, preparation of Bi2MoO6@ZIF-8

[0028] Metal organic framework material ZIF-8 and Bi2MoO6 are added to an alcohol solvent for mixing, stirring and dispersing, and then sent into a reflux reactor, nitrogen is filled to exhaust the air in the reflux reactor, and then refluxed for 12 h. After the reaction is completed, the product is centrifuged and separated, washed with ethanol for several times, and then separated and dried at 65℃ to obtain Bi2MoO6@ZIF-8. The mass ratio of the metal organic framework material ZIF-8 to Bi2MoO6 is 3:1. The alcohol solvent is ethanol. The mass-volume ratio of the metal organic framework material ZIF-8 to the alcohol solvent is 1:300.

[0029] Step 2, preparation of Bi2MoO6@ZIF-8@g-C3N4

[0030] Bi2MoO6@ZIF-8, g-C3N4, and an organic solvent were mixed and stirred uniformly, followed by ultrasonic dispersion for 5 minutes, followed by megasonic dispersion at 0°C for 10 minutes, filtration, and the filter residue was dried at 65°C and ground to obtain the Bi2MoO6@ZIF-8@g-C3N4. The mass ratio of Bi2MoO6@ZIF-8 to g-C3N4 was 10:1.1. The mass-to-volume ratio of Bi2MoO6@ZIF-8 to the organic solvent was 1:20. The ultrasonic frequency during ultrasonic dispersion was 20 kHz, and the megasonic frequency during megasonic dispersion was 0.81 MHz.

[0031] Example 2

[0032] A high-performance metallized film capacitor includes a capacitor housing, a capacitor core located within the capacitor housing, and an epoxy resin encapsulation layer for completely encapsulating the capacitor core. The epoxy resin encapsulation layer is made of a high-performance epoxy resin adhesive that is cured at room temperature under ultraviolet light with a UV wavelength of 360-420nm. The high-performance epoxy resin adhesive is made by mixing epoxy resin adhesive and high-performance composite filler.

[0033] The high-performance composite filler is Bi2MoO6@ZIF-8@g-C3N4, and the mass ratio of Bi2MoO6@ZIF-8@g-C3N4 to epoxy resin adhesive is 1:4. The preparation method of Bi2MoO6@ZIF-8@g-C3N4 includes the following steps:

[0034] Step 1. Preparation of Bi2MoO6@ZIF-8

[0035] Metal-organic framework (MOF) ZIF-8 and Bi2MoO6 were added to an alcohol solvent, mixed and stirred, and dispersed. The mixture was then introduced into a reflux reactor, which was then purged of air by nitrogen and allowed to reflux for 12 hours. After the reaction, the product was centrifuged, washed multiple times with ethanol, separated, and dried at 70°C to obtain Bi2MoO6@ZIF-8. The mass ratio of the MOF ZIF-8 to Bi2MoO6 was 3:1. The alcohol solvent was methanol. The mass-to-volume ratio of the MOF ZIF-8 to the alcohol solvent was 1:330.

[0036] Step 2: Preparation of Bi2MoO6@ZIF-8@g-C3N4

[0037] Bi2MoO6@ZIF-8, g-C3N4, and an organic solvent were mixed and stirred uniformly, followed by ultrasonic dispersion for 5 minutes, followed by megasonic dispersion at 0°C for 12 minutes, filtration, and the filter residue was dried at 70°C and ground to obtain the Bi2MoO6@ZIF-8@g-C3N4. The mass ratio of Bi2MoO6@ZIF-8 to g-C3N4 was 10:1.2. The mass-to-volume ratio of Bi2MoO6@ZIF-8 to the organic solvent was 1:22. The ultrasonic frequency during ultrasonic dispersion was 20 kHz, and the megasonic frequency during megasonic dispersion was 0.81 MHz.

[0038] Example 3

[0039] A high-performance metallized film capacitor includes a capacitor housing, a capacitor core located within the capacitor housing, and an epoxy resin encapsulation layer for completely encapsulating the capacitor core. The epoxy resin encapsulation layer is made of a high-performance epoxy resin adhesive that is cured at room temperature under ultraviolet light with a UV wavelength of 360-420nm. The high-performance epoxy resin adhesive is made by mixing epoxy resin adhesive and high-performance composite filler.

[0040] The high-performance composite filler is Bi2MoO6@ZIF-8@g-C3N4, and the mass ratio of Bi2MoO6@ZIF-8@g-C3N4 to epoxy resin adhesive is 1:4.

[0041] The preparation method of Bi2MoO6@ZIF-8@g-C3N4 comprises the following steps:

[0042] Step 1. Preparation of Bi2MoO6@ZIF-8

[0043] Metal-organic framework (MOF) ZIF-8 and Bi2MoO6 were added to an alcohol solvent, mixed and stirred, and dispersed. The mixture was then introduced into a reflux reactor, which was then purged of air by nitrogen and refluxed for 24 hours. After the reaction, the product was centrifuged, washed multiple times with ethanol, separated, and dried at 80°C to obtain Bi2MoO6@ZIF-8. The mass ratio of the MOF ZIF-8 to Bi2MoO6 was 3.1:1. The alcohol solvent was propanol. The mass-to-volume ratio of the MOF ZIF-8 to the alcohol solvent was 1:400.

[0044] Step 2: Preparation of Bi2MoO6@ZIF-8@g-C3N4

[0045] Bi2MoO6@ZIF-8, g-C3N4, and an organic solvent were mixed and stirred uniformly, followed by ultrasonic dispersion for 5 minutes, followed by megasonic dispersion at 0°C for 15 minutes, filtration, and the filter residue was dried at 80°C and ground to obtain the Bi2MoO6@ZIF-8@g-C3N4. The mass ratio of Bi2MoO6@ZIF-8 to g-C3N4 was 10:1.3. The mass-to-volume ratio of Bi2MoO6@ZIF-8 to the organic solvent was 1:25. The ultrasonic frequency during ultrasonic dispersion was 20 kHz, and the megasonic frequency during megasonic dispersion was 0.81 MHz.

[0046] Comparative Example 1

[0047] The only difference between this example and Example 1 is that Bi2MoO6 is used to replace Bi2MoO6@ZIF-8@g-C3N4 in this example, and the rest is the same as Example 1.

[0048] Comparative Example 2

[0049] The only difference between this example and Example 1 is that ZIF-8 is used to replace Bi2MoO6@ZIF-8@g-C3N4 in this example, and the rest is the same as Example 1.

[0050] Comparative Example 3

[0051] The only difference between this example and Example 1 is that g-C3N4 is used to replace Bi2MoO6@ZIF-8@g-C3N4 in this example, and the rest is the same as Example 1.

[0052] Comparative Example 4

[0053] The only difference between this example and Example 1 is that Bi2MoO6@ZIF-8 is used to replace Bi2MoO6@ZIF-8@g-C3N4 in this example, and the rest is the same as Example 1.

[0054] Comparative Example 5

[0055] The only difference between this example and Example 1 is that a mixture of Bi2MoO6, ZIF-8 and g-C3N4 is used to replace Bi2MoO6@ZIF-8@g-C3N4 in this example, and the rest is the same as Example 1.

[0056] Comparative Example 6

[0057] The only difference between this example and Example 1 is that a mixture of Bi2MoO6@ZIF-8 and g-C3N4 is used to replace Bi2MoO6@ZIF-8@g-C3N4 in this example, and the rest is the same as Example 1.

[0058] Comparative Example 7

[0059] The only difference between this example and Example 1 is that in step 2 of this example, ultrasonic dispersion is first performed for 5 minutes, followed by megasonic dispersion at a temperature of 20° C. for 10 minutes. The rest is the same as in Example 1.

[0060] Comparative Example 8

[0061] The only difference between this example and Example 1 is that in step 2 of this example, ultrasonic dispersion is carried out at a temperature of 0° C. for 20 minutes. The rest is the same as in Example 1.

[0062] Ablation Fire Test Characterization

[0063] A flame gun with a flame temperature of 1000°C was used to burn the capacitor casing. At the same time, a voltage of 1008V (breakdown voltage) was applied to the capacitor (rated voltage 630V) using bare wires. A stopwatch was used to time the process until an explosion or fire occurred. The time taken for the explosion or fire to occur was recorded. The test results are shown in Table 1:

[0064] Table 1

[0065] Test results Example 1 It exploded after burning for 5 seconds, and caught fire inside the shell after burning for another 21 seconds. Example 2 It exploded after burning for 5 seconds, and caught fire inside the shell after burning for another 22 seconds. Example 3 It exploded after burning for 5 seconds, and caught fire inside the shell after burning for another 20 seconds. Reference capacitor After burning for 3 seconds, fire breaks out inside the shell, but there is no explosion Comparative Example 1 After burning for 4 seconds, fire broke out inside the shell, but there was no explosion. Comparative Example 2 After burning for 3 seconds, fire breaks out inside the shell, but there is no explosion Comparative Example 3 After burning for 2 seconds, fire breaks out inside the shell, but there is no explosion Comparative Example 4 After burning for 5 seconds, fire breaks out inside the shell, but there is no explosion Comparative Example 5 After burning for 5 seconds, the shell will catch fire and produce an explosion 3 seconds after the fire starts. Comparative Example 6 After burning for 6 seconds, the shell will catch fire and produce an explosion sound 4 seconds after the fire starts.

[0066] In Table 1, the reference capacitor is an existing thin film capacitor, and the epoxy resin encapsulation layer used therein is made by doping an existing epoxy resin adhesive with spherical alumina and then curing it. The mass ratio of spherical alumina to the existing epoxy resin adhesive in the existing epoxy resin adhesive (purchased from Beijing Luhang Hangte Technology Co., Ltd.) is 1:4; UV light with a wavelength of 360-420nm is used to assist curing during the curing process.

[0067] Because in a high temperature environment, the local film can easily soften, causing the voltage in the local area to instantly reach the breakdown voltage. Only under the test of the dual harsh environment of breakdown voltage and high temperature burning can the capacitor's resistance to ablation and fire be reflected.

[0068] In Table 1, if the film capacitor explodes after a period of burning and then catches fire, this is an ideal situation. This is because during use, the film capacitor will generate a huge impact force at the moment of explosion, which can instantly sever at least one of the two leads of the capacitor, thus instantly disconnecting the capacitor and cutting off the power supply. Even if the burning is continued for a long time later, it will only cause scorching; only after continuous burning for a period of time will the epoxy resin encapsulation layer burn extensively.

[0069] However, if the film capacitor burns first and then explodes, it is meaningless because the capacitor has already caught fire and it does not matter whether it explodes or not.

[0070] Stirring Test

[0071] If g-C3N4 is not completely composited with Bi2MoO6@ZIF-8, when the powder prepared in step 2 (hereinafter referred to as product powder) is poured into the epoxy resin adhesive and stirred, it is found that due to the light weight of g-C3N4, some product powder always floats on the surface of the epoxy resin adhesive, and the difference ΔX between the solid content of the upper and lower adhesive layers is large.

[0072] The test results of Example 1, Comparative Example 7 and Comparative Example 8 are shown in Table 2:

[0073] Table 2

[0074] Test results Example 1 After stirring for 30 minutes, ΔX = 0.2% Comparative Example 7 After stirring for 60 minutes, ΔX = 5.9% Comparative Example 8 After stirring for 60 minutes, ΔX = 13.6%

[0075] It can be seen that in the composite process of g-C3N4 and Bi2MoO6@ZIF-8, the use of low temperature combined with megasonic dispersion can significantly improve the composite effect and is conducive to the combination of g-C3N4 and Bi2MoO6@ZIF-8.

[0076] In the above embodiment, the CAS number of the metal-organic framework material ZIF-8 is 59061-53-9. The mass-to-volume ratio is the ratio of the mass of a first substance to the volume of a second substance. For example, a mass-to-volume ratio of the metal-organic framework material ZIF-8 to the alcohol solvent is 1:300, corresponding to a mass of 1g of the metal-organic framework material ZIF-8 and a volume of 300ml of the alcohol solvent. g-C3N4 is graphite-phase carbon nitride, purchased from Suzhou Kaifa New Materials Technology Co., Ltd. The capacitor housings are all aluminum.

[0077] 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 above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above 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 high-performance metallized film capacitor comprising a capacitor housing, a capacitor core located within the capacitor housing, and an epoxy resin encapsulation layer for completely encapsulating the capacitor core, characterized in that: The epoxy resin encapsulation layer is made of a high-performance epoxy resin adhesive that is cured at room temperature under ultraviolet light with a UV wavelength of 360-420 nm. The high-performance epoxy resin adhesive is made by mixing an epoxy resin adhesive and a high-performance composite filler; the high-performance composite filler is Bi2MoO6@ZIF-8@g-C3N4; The preparation method of Bi2MoO6@ZIF-8@g-C3N4 comprises the following steps: Step 1. Preparation of Bi2MoO6@ZIF-8 The metal organic framework material ZIF-8 and Bi2MoO6 are added to an alcohol solvent, mixed and stirred to disperse, and then sent into a reflux reactor. The air in the reflux reactor is first filled with nitrogen to exhaust, and then refluxed for 12 to 24 hours. After the reaction is completed, the product is centrifuged, washed with ethanol multiple times, separated, and dried to obtain Bi2MoO6@ZIF-8; Step 2: Preparation of Bi2MoO6@ZIF-8@g-C3N4 Bi2MoO6@ZIF-8, g-C3N4 and an organic solvent are mixed and stirred uniformly, first ultrasonically dispersed for 5 minutes, then megasonic dispersed at a temperature of 0°C for 10-15 minutes, filtered, and the filter residue is dried and ground to obtain the Bi2MoO6@ZIF-8@g-C3N4.

2. The high-performance metallized film capacitor according to claim 1, characterized in that: In step 1, the mass ratio of the metal organic framework material ZIF-8 and Bi2MoO6 is (3~3.1):

1.

3. The high-performance metallized film capacitor according to claim 1, characterized in that: In step 1, the alcohol solvent is one or more of methanol, ethanol, propanol, and butanol.

4. The high-performance metallized film capacitor according to claim 1, characterized in that: In step 1, the mass volume ratio of the metal organic framework material ZIF-8 to the alcohol solvent is 1:(300~400).

5. The high-performance metallized film capacitor according to claim 1, characterized in that: In step 2, the mass ratio of Bi2MoO6@ZIF-8 to g-C3N4 was 10:(1.1~1.3).

6. The high-performance metallized film capacitor according to claim 1, characterized in that: In step 2, the mass volume ratio of Bi2MoO6@ZIF-8 to organic solvent is 1:(20~25).

7. The high-performance metallized film capacitor according to claim 1, characterized in that: In step 2, the ultrasonic frequency during ultrasonic dispersion is 20 kHz, and the megasonic frequency during megasonic dispersion is 0.81 MHz.

8. The high-performance metallized film capacitor according to claim 1, characterized in that: In step 1, the drying temperature is 65-80°C; In step 2, the drying temperature of the filter residue is 65-80°C.