阅读说明：本技术 储能聚合物电介质及其制备方法和应用 (Energy storage polymer dielectric and preparation method and application thereof ) 是由 党智敏 裴家耀 钟少龙 于 2021-06-21 设计创作，主要内容包括：本发明公开了储能聚合物电介质及其制备方法和应用。该储能聚合物电介质包括：聚合物电介质基膜和金属氧化物薄膜。其制备方法包括：预先洁净电介质薄膜,然后在Ar和O-(2)混合气氛中,以金属氧化物为靶材,采用磁控溅射,在洁净的聚合物电介质基膜上沉积金属氧化物薄膜。本发明提出的储能聚合物电介质制备及充放电效率提升方法具有以下优点：沉积速率快,升温小,对聚合物电介质基膜损伤小；溅射的薄膜与聚合物电介质结合性好；溅射的金属氧化物纯度高,成膜致密且均匀性好；溅射后制得的复合储能电介质较之原基膜,充放电效率大幅提升,击穿强度也有改善；该工艺具有良好的重复性、薄膜制备参数容易调节,具有实现工业化的潜力。(The invention discloses an energy storage polymer dielectric and a preparation method and application thereof. The energy storage polymer dielectric includes: a polymer dielectric based film and a metal oxide film. The preparation method comprises the following steps: cleaning the dielectric film in advance, then cleaning the dielectric film in Ar and O 2 In a mixed atmosphere, metal oxide is used as a target material, and a metal oxide film is deposited on a clean polymer dielectric medium base film by adopting magnetron sputtering. The method for preparing the energy storage polymer dielectric and improving the charge and discharge efficiency has the following advantages: the deposition rate is high, the temperature rise is small, and the damage to the polymer dielectric base film is small; the sputtered film has good bonding property with the polymer dielectric medium; the sputtered metal oxide has high purity, compact film formation and good uniformity; compared with the original base film, the composite energy storage dielectric prepared after sputtering has greatly improved charge-discharge efficiency and breakdown strength; the process has good repeatability, easily adjustable film preparation parameters, and good implementation effectThe potential for industrialization.)

1. An energy storage polymer dielectric, comprising: a polymer dielectric base film and a metal oxide thin film formed on a surface of the polymer dielectric thin film.

2. The energy storage polymer dielectric of claim 1, wherein the polymer dielectric base film is formed from at least one selected from the group consisting of polypropylene, polyethylene terephthalate, polyetherimide, polyimide, polyvinylidene fluoride-hexafluoropropylene.

3. The energy storage polymer dielectric of claim 1, wherein the metal oxide thin film is formed from at least one selected from the group consisting of aluminum oxide, silicon dioxide, titanium dioxide, and hafnium dioxide.

4. An energy storage polymer dielectric according to claim 1, wherein the metal oxide thin film has a thickness of 50 to 250 nm.

5. A method of making an energy storage polymer dielectric according to any of claims 1 to 4, comprising:

(1) providing a polymer dielectric base film;

(2) at Ar and O₂And in a mixed atmosphere, forming a metal oxide film on the surface of the polymer dielectric base film by magnetron sputtering by taking metal oxide as a target material.

6. The method of claim 5, wherein the polymer dielectric base film is previously subjected to a cleaning process.

7. The method of claim 5, wherein Ar and O are₂In a mixed atmosphere, Ar and O₂The flow ratio of (1) to (5) is 40.

8. The method of claim 5, wherein in the magnetron sputtering, a distance between the target and the polymer dielectric substrate film is 5 to 15cm, a working gas pressure is 0.1 to 1Pa, and a sputtering power is 100 to 300W.

9. An energy storage polymer dielectric capacitor, comprising:

an energy storage polymer dielectric according to any one of claims 1 to 4 or prepared by the process of any one of claims 5 to 8;

an electrode formed on a surface of the metal oxide thin film in the energy storage polymer dielectric.

Technical Field

The invention relates to the field of energy storage polymer dielectrics, in particular to an energy storage polymer dielectric with high breakdown strength and charge-discharge efficiency, and a preparation method and application thereof.

Background

Every update of energy control and use can push the human society to make a deep revolution. Particularly after the second industrial revolution, the use of electrical energy has brought human society into the "electric age". The electric energy has the following characteristics: the product can be used immediately and is not easy to store. The capacitor can store electric energy in the form of electrostatic energy by means of polarization, and has higher power density due to the characteristic of polarization energy storage. Also, capacitors are an important passive device that regulates the flow of energy and the transfer of information in power systems and various electronic devices. The polymer dielectric has higher breakdown strength, good self-healing property and good processing property, and plays a very important role in the capacitor.

Capacitors are often subjected to high electric field strength during operation, and the operating temperature is usually high due to their own losses and the operating environment. The leakage current of the polymer dielectric can be greatly increased under a large electric field and high temperature, and the generated Joule heat further increases the working temperature, so that the insulation performance is continuously deteriorated, and finally the thermal runaway of devices and devices is caused. The loss of the capacitor not only affects the efficiency of the capacitor during operation, but also generates heat, which causes severe thermal management problems for the capacitor. The loss level of the capacitor determines the use condition and scene of the capacitor. The efficiency of the energy storage dielectric determines the upper limit of the overall efficiency of the capacitor. The level of dielectric loss is one of the determining criteria for whether a dielectric can be used for a particular capacitor.

Meanwhile, in order to increase the energy storage density of the energy storage polymer dielectric, research works have often used a ferroelectric polymer as a matrix, and the like. The methods improve the energy storage density and simultaneously cause the problems of loss increase and efficiency reduction. Therefore, improving the charge-discharge efficiency of polymer dielectrics, especially at elevated temperatures, is of great importance for the research and use of energy storage dielectrics.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art. To this end, it is an object of the present invention to provide energy storage polymer dielectrics and methods for their preparation and use.

In one aspect of the invention, an energy storage polymer dielectric is presented. According to an embodiment of the invention, the energy storage polymer dielectric comprises: a polymer dielectric base film and a metal oxide thin film formed on a surface of the polymer dielectric thin film.

The inventor finds that the metal oxide has small temperature variation, high dielectric constant and can effectively inhibit charge injection from an electrode to a dielectric, thereby improving the breakdown strength and the charge-discharge efficiency of the dielectric. In the energy storage polymer dielectric according to the embodiment of the invention, the metal oxide film can be used as an isolation layer between the polymer electrolyte base film and the capacitor electrode, and the effect of improving the breakdown strength of the polymer dielectric after the working temperature is increased and the charge-discharge efficiency under large electric field intensity is achieved. In addition, the process for preparing the metal oxide film has good repeatability, the preparation parameters are easy to control, and the method has the potential of realizing industrialization.

In addition, the energy storage polymer dielectric according to the above embodiment of the present invention may also have the following additional technical features:

in some embodiments of the present invention, the polymer dielectric base film is formed of at least one selected from the group consisting of polypropylene, polyethylene terephthalate, polyetherimide, polyimide, polyvinylidene fluoride-hexafluoropropylene.

In some embodiments of the present invention, the metal oxide thin film is formed of at least one selected from the group consisting of aluminum oxide, silicon dioxide, titanium dioxide, and hafnium dioxide.

In some embodiments of the present invention, the thickness of the metal oxide thin film is 50 to 250 nm.

In another aspect of the invention, the invention provides a method of making the energy storage polymer dielectric of the above embodiments. According to an embodiment of the invention, the method comprises: (1) providing a polymer dielectric base film; (2) at Ar and O₂And in a mixed atmosphere, forming a metal oxide film on the surface of the polymer dielectric base film by magnetron sputtering by taking metal oxide as a target material.

According to the method for preparing the energy storage polymer dielectric, the metal oxide film is formed on the surface of the polymer dielectric base film through magnetron sputtering, the deposition rate is high, the temperature rise is low, the damage to the polymer electrolyte base film is low, and the metal oxide film formed through sputtering is high in purity, compact, good in uniformity and good in combination with the base film. The method has the advantages of good process repeatability, easy control of preparation parameters and potential for realizing industrialization. In addition, by adding oxygen in Ar and O₂The magnetron sputtering is carried out in the mixed atmosphere, so that the problem of oxygen element loss in the process of magnetron sputtering of the oxide can be effectively solved, and the stoichiometric ratio of the metal element and the oxygen element in the metal oxide film obtained by sputtering is ensured to be the same as that of the target material.

In addition, the method for preparing the energy storage polymer dielectric according to the above embodiment of the present invention may further have the following additional technical features:

in some embodiments of the present invention, the polymer dielectric base film is previously subjected to a cleaning process.

In some embodiments of the invention, the Ar and O are₂In a mixed atmosphere, Ar and O₂The flow ratio of (1) to (5) is 40.

In some embodiments of the present invention, in the magnetron sputtering, a distance between the target and the polymer dielectric substrate film is 5 to 15cm, a working pressure is 0.1 to 1Pa, and a sputtering power is 100 to 300W.

In yet another aspect of the invention, an energy storage polymer dielectric capacitor is provided. According to an embodiment of the invention, the energy storage polymer dielectric capacitor comprises: an energy storage polymer dielectric, wherein the energy storage polymer dielectric is the energy storage polymer dielectric of the embodiment or the energy storage polymer dielectric prepared by the method of the embodiment; and an electrode formed on a surface of the metal oxide thin film in the energy storage polymer dielectric. Thus, the energy storage polymer dielectric capacitor has excellent breakdown strength at high temperature and excellent charge and discharge efficiency at large electric field strength.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a graph of the breakdown strength value test results at 200 ℃ for the energy storage polymer dielectric samples of example 1 and comparative example 1;

fig. 2 is a graph showing the results of testing the charge and discharge efficiency and discharge energy values at 200 c for the energy storage polymer dielectric samples of example 1 and comparative example 1.

Detailed Description

The following describes embodiments of the present invention in detail. The following examples are illustrative only and are not to be construed as limiting the invention. The examples, where specific techniques or conditions are not indicated, are to be construed according to the techniques or conditions described in the literature in the art or according to the product specifications. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available.

In one aspect of the invention, an energy storage polymer dielectric is presented. According to an embodiment of the invention, the energy storage polymer dielectric comprises: a polymer dielectric base film and a metal oxide thin film formed on a surface of the polymer dielectric thin film.

Energy storage polymer dielectrics according to embodiments of the present invention are described in further detail below.

In the energy storage polymer dielectric of the present invention, the specific kind of the polymer dielectric base film is not particularly limited. According to some embodiments of the present invention, the polymer dielectric base film may be formed of at least one selected from the group consisting of polypropylene, polyethylene terephthalate, polyetherimide, polyimide, polyvinylidene fluoride-hexafluoropropylene. The polymer material has higher breakdown strength value and is a potential candidate of the energy storage polymer.

According to some embodiments of the present invention, the metal oxide thin film may be formed of at least one selected from the group consisting of aluminum oxide, silicon dioxide, titanium dioxide, and hafnium dioxide. The metal oxide has a high dielectric constant value and a wide forbidden band width, and the metal oxide film formed by the metal oxide can further improve the breakdown strength and the charge and discharge efficiency of the energy storage polymer dielectric.

According to some embodiments of the present invention, the thickness of the metal oxide thin film may be 50 to 250nm, such as 50nm, 100nm, 150nm, 200nm, 250nm, and the like. By controlling the thickness of the metal oxide film within the range, the breakdown strength and the charge-discharge efficiency of the energy storage polymer dielectric can be further improved; if the thickness of the metal oxide film is too small, it may be difficult to effectively suppress charge injection, resulting in poor effects; if the thickness of the metal oxide film is too great, more defects may form in the metal oxide, affecting the overall performance of the material.

In another aspect of the invention, a method of making an energy storage polymer dielectric is provided. Methods of making energy storage polymer dielectrics according to embodiments of the present invention are described in further detail below.

First, according to an embodiment of the present invention, a polymer dielectric based film is provided.

The specific kind of the polymer dielectric base film is not particularly limited. According to some embodiments of the present invention, the polymer dielectric base film may be formed of at least one selected from the group consisting of polypropylene, polyethylene terephthalate, polyetherimide, polyimide, polyvinylidene fluoride-hexafluoropropylene.

According to some embodiments of the present invention, the polymer dielectric base film is previously subjected to a cleaning process to remove impurities and stains remaining on the surface of the base film; since impurities and dirt may cause distortion of the electric field after the plate capacitor is pressurized, it is necessary to pay special attention. In the whole operation process, the dielectric film should be kept clean all the time to avoid dirt and scratches. In addition, the cleaning treatment is not particularly limited, and those skilled in the art can select the cleaning treatment according to actual needs.

Further, according to embodiments of the present invention, in Ar and O₂And in a mixed atmosphere, forming a metal oxide film on the surface of the polymer dielectric base film by magnetron sputtering by taking metal oxide as a target material. The metal oxide film is formed on the surface of the polymer dielectric base film through magnetron sputtering, the deposition rate is high, the temperature rise is small, the damage to the polymer dielectric base film is small, and the metal oxide film formed through sputtering has high purity, compactness, good uniformity and good associativity with the base film. The method has the advantages of good process repeatability, easy control of preparation parameters and potential for realizing industrialization. In addition, by adding oxygen in Ar and O₂The magnetron sputtering is carried out in the mixed atmosphere, so that the problem of oxygen element loss in the process of magnetron sputtering of the oxide can be effectively solved, and the stoichiometric ratio of the metal element and the oxygen element in the metal oxide film obtained by sputtering is ensured to be the same as that of the target material.

According to some embodiments of the invention, Ar and O are as described above₂In a mixed atmosphere, Ar and O₂The flow rate ratio of (A) may be 40 (1) - (5), for example, 40:1, 40:2, 40:3, 40:4, 40:5, etc.

According to some embodiments of the present invention, in the magnetron sputtering, a distance between the target and the polymer dielectric base film may be 5 to 15cm (e.g., 5cm, 8cm, 10cm, 12cm, 15cm, etc.), an operating gas pressure may be 0.1 to 1Pa (e.g., 0.1Pa, 0.2Pa, 0.5Pa, 0.8Pa, 1Pa, etc.), and a sputtering power may be 100 to 300W (e.g., 100W, 150W, 200W, 250W, 300W, etc.). During the sputtering process, the target elements are sputtered to carry energy, so that a significant temperature rise occurs after the coating is formed on the polymer, and therefore, the distance between the target and the substrate and the sputtering power need to be adjusted within the above range, so that the thermal damage of the polymer film during the sputtering process can be reduced. In addition, by controlling the working gas pressure in the magnetron sputtering within the above range, a stable sputtering effect and a sputtered metal oxide layer with high purity can be achieved.

According to some embodiments of the invention, in order to avoid rubbing during the double-sided coating process in magnetron sputtering, a suitable fixture can be used for clamping the polymer dielectric base film so as to facilitate the turnover for secondary coating.

In yet another aspect of the invention, an energy storage polymer dielectric capacitor is provided. According to an embodiment of the invention, the energy storage polymer dielectric capacitor comprises: an energy storage polymer dielectric, wherein the energy storage polymer dielectric is the energy storage polymer dielectric of the embodiment or the energy storage polymer dielectric prepared by the method of the embodiment; and an electrode formed on a surface of the metal oxide thin film in the energy storage polymer dielectric. Thus, the energy storage polymer dielectric capacitor has excellent breakdown strength at high temperature and excellent charge and discharge efficiency at large electric field strength.

In addition, it should be noted that the energy storage polymer dielectric capacitor further includes all the features and advantages described above for the energy storage polymer dielectric, and thus, detailed description thereof is omitted.

The invention will now be described with reference to specific examples, which are intended to be illustrative only and not to be limiting in any way.

Example 1

Using a polyetherimide dielectric film as a base material (purchased from Polyk company in the United states), and ultrasonically removing residual impurities and dirt on the surface in alcohol; then, magnetron sputtering was carried out using aluminum oxide as a target (purchased from Zhongnuo New materials science and technology Co., Ltd.) with a distance of 10cm between the target and the substrate between Ar and O₂(40:4) in a mixed atmosphere, depositing aluminum oxide on the surface of the film by magnetron sputtering, wherein the working pressure is 0.5 Pa; the sputtering time is adjusted according to the thickness, and the sputtering thickness is 150 nm; the sputtering power was 200W. And depositing metal oxide films on the two sides of the original polymer dielectric base film to obtain an energy storage polymer dielectric sample.

Comparative example 1

The polyetherimide dielectric film (available from Polyk company, usa) was ultrasonically treated in alcohol to remove the residual impurities and dirt on the surface, and thus an energy storage polymer dielectric sample was obtained.

Test example

(1) And (3) breakdown test: a voltage was generated by a high voltage power supply of poler high voltage power supply ltd at a boosting rate of about 500V/s, and a metal electrode was formed on the surface of the energy storage polymer dielectric sample prepared in example 1 and comparative example 1 by gold plating for testing.

(2) Testing discharge energy density and charge-discharge efficiency: the polarization curve of the material obtained by Precision Multiferroic test system of radiation Technologies was tested, and the discharge energy density and the charge-discharge efficiency of the material were obtained from the polarization curve. Metal electrodes were formed on the surfaces of the energy storage polymer dielectric samples prepared in example 1 and comparative example 1 by gold plating for the test, and the test voltage waveform was a triangular wave voltage of 100 Hz. The high-temperature test environment is obtained by heating silicone oil by adopting an IKA temperature control magnetic stirrer.

The test results are shown in fig. 1 and 2. As can be seen from fig. 1, the breakdown strength at high temperature of the inventive method for preparing an energy storage polymer dielectric using a metal oxide is significantly improved compared to the untreated sample of comparative example 1. As can be seen from fig. 2, in comparative example 1, at 200 ℃, the charge and discharge efficiency rapidly deteriorates and the discharge energy density also falls to some extent as the electric field strength increases. In contrast, in example 1, the charging and discharging efficiency is significantly improved compared to comparative example 1 at the same electric field strength, and the discharge energy density is less affected by the increase of the loss at a high field.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.