1. A preparation method and an energy storage performance optimization method of an all-organic composite dielectric medium are characterized in that a polyvinylidene fluoride matrix is respectively blended with organic polymers such as Polyimide (PI), polyether sulfone (PESU), cyanoethyl cellulose (CR-C), cyanoethyl pullulan (CR-S) and the like to prepare the all-organic dielectric medium.

2. The method of claim 1, wherein each of the organic polymers is introduced in an amount of 5 wt% based on the total mass of the polyvinylidene fluoride-based dielectrics.

3. The method for preparing the all-organic composite dielectric and optimizing the energy storage performance of the all-organic composite dielectric according to claim 2, wherein the thickness of the composite film is 9-18 μm.

4. The method for preparing all-organic composite dielectric and optimizing energy storage performance according to claims 1-3, wherein the preparation method comprises the following steps:

the method comprises the following steps:

putting a certain amount of PI, PESU and CR-C, CR-S into a plastic package bag, baking for a period of time at a certain temperature in a forced air drying oven, respectively weighing polyvinylidene fluoride powder with equal mass, dissolving the polyvinylidene fluoride powder in a certain amount of N-N dimethylformamide solution, and magnetically stirring the polyvinylidene fluoride powder at a proper temperature until the powder is uniformly dispersed. After the polyvinylidene fluoride is dissolved uniformly, respectively adding PI, PESU and CR-C, CR-S, and continuously stirring for a period of time to obtain a blended all-organic precursor solution;

step two:

putting the precursor solution obtained in the step one into a vacuum drying oven, setting the temperature and time, vacuumizing, standing for a plurality of hours, and taking out the colloid for later use after the bubbles in the precursor solution are completely separated out;

step three:

preparing an all-organic composite medium wet film by a blade coating method, placing a cleaned glass plate on an automatic film coating machine, leveling a scraper, determining the number of rotation grids of the scraper, and placing the wet film prepared by the blade coating method in a blast drying oven at a proper temperature for drying and heat treating for a plurality of hours by adjusting the propelling speed and the propelling position of the automatic film coating machine;

step four:

hot pressing different all-organic composite medium films by adopting a hot pressing and quenching process, and performing gradient heating hot pressing treatment: the first stage has certain hot pressing temperature and maintains pressure under proper pressure; and in the second stage, pressure relief and bubble removal treatment are carried out, finally, the temperature of the composite film is rapidly reduced to room temperature through a water cooling device, and pressure maintaining is carried out under certain pressure to obtain a uniform and compact all-organic composite medium with proper thickness.

5. The method according to claim 4, wherein the step four comprises placing the fully organic composite thin film in a hot-pressing mold plate by a hot-pressing process, and performing gradient heating hot-pressing treatment by hot-pressing treatment: in the first stage, the hot pressing temperature is 100-110 ℃, and the pressure is maintained for 15-20 min under 1-5 MPa; and (3) performing pressure relief and bubble removal treatment in the second stage, wherein the hot pressing temperature in the third stage is 140-160 ℃, and the pressure is maintained at 15-20 MPa for 15-20 min. And finally, rapidly cooling the temperature of the composite film to room temperature through a water cooling device, and maintaining the pressure for 1-5 min under 1-5 MPa to obtain a compact all-organic composite medium with the thickness of about 10-20 microns.

6. The method for preparing all-organic composite dielectric and optimizing energy storage performance according to claim 5, wherein the method comprises the following steps: the breakdown strength range of the pure PVDF is 330 kV/mm-440 kV/mm, 5 wt.% of PI is introduced into the PVDF, and the breakdown strength range of the PI/PVDF composite medium is 330 kV/mm-470 kV/mm; 5 wt.% of PESU is introduced, and the breakdown strength range of the PESU/PVDF composite dielectric is 310 kV/mm-490 kV/mm; 5 wt.% of CR-C is introduced, and the breakdown strength range of the CR-C/PVDF composite medium is 200 kV/mm-300 kV/mm; 5 wt.% of CR-S is introduced, and the breakdown strength of the CR-S/PVDF composite dielectric ranges from 330kV/mm to 500 kV/mm.

7. The method for preparing all-organic composite dielectric and optimizing energy storage performance according to claim 6, wherein the method comprises the following steps: the pure PVDF has a dielectric constant range of 8.5-10 at a frequency of 1Hz and a dielectric constant range of 1 x 10⁷The dielectric constant range is 4-5 at Hz frequency. 5 wt.% of PI is introduced into PVDF, and the dielectric constant of the PI/PVDF composite medium is within the range of 10-11 at the frequency of 1Hz and within the range of 1 × 10⁷The dielectric constant range of the PI/PVDF composite medium is 5-5.5 under the frequency of Hz. Introducing 5 wt.% of PESU into the PVDF, wherein the range of the dielectric constant of the PESU/PVDF composite medium is 8.5-9 at the frequency of 1Hz and is 1 multiplied by 10⁷Under the frequency of Hz, the range of the dielectric constant of the PESU/PVDF composite medium is 4-4.4. 5 wt.% of CR-C is introduced into PVDF, and the dielectric constant of the CR-C/PVDF composite medium is in a range of 9.5-10 at a frequency of 1Hz and is in a range of 1 x 10⁷The dielectric constant range of the CR-C/PVDF composite medium is 4.5-10 under the frequency of Hz. 5 wt.% of CR-S is introduced into PVDF, the dielectric constant of the CR-S/PVDF composite medium is 8.5-9.2 at the frequency of 1Hz and is 1 multiplied by 10⁷The dielectric constant range of the CR-S/PVDF composite medium is 4.2-4.4 under the frequency of Hz.

8. The method for preparing all-organic composite dielectric and optimizing energy storage performance according to claim 7, wherein the method comprises the following steps: the pure PVDF has a dielectric loss range of 0.13-0.18 at a frequency of 1Hz and a dielectric loss range of 1 x 10⁷The dielectric loss range is 0.2-0.3 at Hz frequency. 5 wt.% of PI is introduced into the PVDF, and the dielectric loss range of the PI/PVDF composite medium is 0.08-0.12 at the frequency of 1Hz and is 1 multiplied by 10⁷Under the frequency of Hz, the dielectric loss range of the PI/PVDF composite medium is 0.12-0.15. Introducing 5 wt.% of PESU into PVDF, wherein the dielectric loss range of the PESU/PVDF composite medium is 0.13-0.15 at the frequency of 1Hz and is 1 multiplied by 10⁷At a frequency of Hz, PESU-The dielectric loss range of the PVDF composite medium is 0.18-0.21. 5 wt.% of CR-C is introduced into PVDF, and the dielectric loss range of the CR-C/PVDF composite medium is 0.11-0.14 at the frequency of 1Hz and is 1 multiplied by 10⁷The dielectric loss range of the CR-C/PVDF composite medium is 0.15-0.17 under the frequency of Hz. 5 wt.% of CR-S is introduced into PVDF, and the dielectric loss range of the CR-S/PVDF composite medium is 0.09-0.12 at the frequency of 1Hz and is 1 multiplied by 10⁷The dielectric loss range of the CR-S/PVDF composite medium is 0.21-0.24 under the frequency of Hz.

9. The method for preparing an all-organic composite dielectric and optimizing energy storage performance according to claim 8, wherein the method comprises the following steps: the discharge energy density range of pure PVDF under the electric field intensity of 440kV/mm is 10-12.5J/cm³.5 wt.% of PI is introduced into the PVDF, and the electric energy density range of the PI/PVDF composite medium under the electric field intensity of 424kV/mm is 12-13.5J/cm³.5 wt.% of PESU is introduced into the PVDF, and the discharge energy density range of the PESU/PVDF composite medium is 12-14J/cm under the electric field strength of 434kV/mm³.5 wt.% of CR-C is introduced into PVDF, and the discharge energy density range of the CR-C/PVDF composite medium under an electric field of 270kV/mm is 4.3-5J/cm³.5 wt.% of CR-S is introduced into PVDF, and the discharge energy density of the CR-S/PVDF composite medium under an electric field of 430kV/mm is 12-13.5J/cm³。

10. The method for preparing an all-organic composite dielectric and optimizing energy storage performance according to claim 9, wherein the method comprises the following steps: the range of the charge-discharge efficiency of PVDF under the electric field strength of 440kV/mm is 30% -45%, the range of the charge-discharge efficiency of PI/PVDF composite medium under the electric field strength of 424kV/mm is 50% -55%, the range of the charge-discharge efficiency of PESU/PVDF composite medium under the electric field strength of 434kV/mm is 48% -52%, the range of the charge-discharge efficiency of CR-C/PVDF composite medium under the electric field strength of 270kV/mm is 40% -48%, and the range of the charge-discharge efficiency of CR-S/PVDF composite medium under the electric field strength of 430kV/mm is 47% -52%.

Background

The all-organic composite medium based on blending of polyvinylidene fluoride (PVDF) and an organic medium has the advantages of good compatibility, good toughness, simple forming, higher breakdown strength and the like, and has wide application prospect in the field of dielectric energy storage. Since PVDF is used as a ferroelectric polymer dielectric material, it has high polarization strength and dielectric constant, and the corresponding dielectric loss is also high. Therefore, how to reduce the dielectric loss while improving the energy storage density of the composite medium using the polyvinylidene fluoride as the matrix becomes a key point and a difficulty in obtaining the composite material with excellent performance. And organic polymers such as Polyimide (PI), polyether sulfone (PESU), cyanoethyl cellulose (CR-C), cyanoethyl pullulan (CR-S) and the like belong to linear dielectric materials, and have high insulating strength and low dielectric loss. In the work, a novel linear dielectric material is added into polyvinylidene fluoride, and the electrical and mechanical properties of the all-organic composite medium can be improved based on the principle of similar intermiscibility. Finally, this research is expected to drive the development of high performance polymer-based nanocomposite dielectrics with the advantages of integration, high efficiency, flexibility, light weight, and low cost, which can be used in advanced commercial, aerospace, and military fields.

Disclosure of Invention

The invention aims to solve the technical problems of low energy storage density and low breakdown strength of a medium, and provides a preparation method of an all-organic composite dielectric and an energy storage performance optimization method.

The technical scheme of the invention is as follows:

a method for preparing all-organic composite dielectric and optimizing energy storage performance is characterized in that polyvinylidene fluoride base bodies are respectively blended with organic polymers such as PI, PESU, CR-C, CR-S and the like to prepare the all-organic dielectric.

Further, the preparation and energy storage performance optimization method of the all-organic composite dielectric medium is characterized in that the organic polymer accounts for 5 wt% of the mass fraction of the polyvinylidene fluoride-based composite dielectric medium.

A preparation and energy storage performance optimization method of an all-organic composite dielectric medium is characterized by comprising the following steps:

the method comprises the following steps:

putting a certain amount of PI, PESU and CR-C, CR-S into a plastic package bag, baking for a period of time at a certain temperature in a forced air drying oven, respectively weighing polyvinylidene fluoride powder with equal mass, dissolving the polyvinylidene fluoride powder in a certain amount of N-N Dimethylformamide (DMF) solution, and magnetically stirring the solution at a proper temperature until the powder is uniformly dispersed. After the polyvinylidene fluoride is dissolved uniformly, respectively adding PI, PESU and CR-C, CR-S, and continuously stirring for a period of time to obtain a blended all-organic precursor solution;

step two:

putting the precursor solution obtained in the step one into a vacuum drying oven, setting the temperature and time, vacuumizing, standing for a plurality of hours, and taking out the colloid for later use after the bubbles in the precursor solution are completely separated out;

step three:

preparing an all-organic composite medium wet film by a blade coating method, placing a cleaned glass plate on an automatic film coating machine, leveling a scraper, determining the number of rotation grids of the scraper, and placing the wet film prepared by the blade coating method in a blast drying oven at a proper temperature for drying and heat treating for a plurality of hours by adjusting the propelling speed and the propelling position of the automatic film coating machine;

step four:

hot pressing different all-organic composite medium films by adopting a hot pressing and quenching process, and performing gradient heating hot pressing treatment: the first stage has certain hot pressing temperature and maintains pressure under proper pressure; and in the second stage, pressure relief and bubble removal treatment are carried out, finally, the temperature of the composite film is rapidly reduced to room temperature through a water cooling device, and pressure maintaining is carried out under certain pressure to obtain a uniform and compact all-organic composite medium with proper thickness.

Further, in the step one, PI, PESU and CR-C, CR-S are placed in a forced air drying oven for heat treatment for 6 hours at the temperature of 60 ℃. Then, sequentially weighing five parts of 1-2 g polyvinylidene fluoride powder by using a digital balance, placing the five parts in a beaker, respectively weighing 10-20 ml of DMF (dimethyl formamide) by using a pipette, adding dried 0.1-0.5 g of PI, 0.1-0.5 g of PESU, 0.1-0.5 g of CR-C and 0.1-0.5 g of CR-S into the DMF, respectively and sequentially stirring at room temperature until the solutions are completely dissolved, and stirring at room temperature for 12h until the solutions are uniformly dispersed.

And further, in the second step, the precursor solution obtained by blending the all-organic composite medium in the first step is transferred into a vacuum drying oven, vacuumized and kept stand for 3 hours, and taken out for later use after bubbles in the precursor solution are separated out.

Further, wiping a clean glass plate prepared in advance with alcohol, placing the glass plate on an automatic film coating machine after confirming that the surface is smooth, setting the advancing speed of a push broach of the film coating machine to be 3-8 cm/s and the advancing distance of the push broach to be 20-30 cm, taking out the scraper, placing the scraper on the glass plate, leveling the scraper, rotating the spiral scale of the scraper for 10-30 grids, pouring the precursor solution prepared in the second step onto the surface of the glass plate, properly inclining the glass plate to enable the precursor solution to flow to the scraper, and then carrying out film coating treatment.

Furthermore, the film prepared by the blade coating method is marked according to different doping proportions and is transferred to an air-blast drying oven, the temperature is set to be 60-150 ℃, and the time is set to be 4-12 hours. And then taking out the glass plate, transferring the glass plate into a vacuum drying box, vacuumizing the vacuum drying box, setting the temperature to be 60-150 ℃, carrying out heat treatment in the vacuum drying box for 12 hours, taking out the glass plate, and tearing off the film by using a blade under the action of deionized water and placing the film in a polyester film for later use.

Further, the step four is that a hot pressing process is adopted, the all-organic composite film is placed in a hot pressing template, and after hot pressing treatment, gradient heating hot pressing treatment is carried out: in the first stage, the hot pressing temperature is 100-120 ℃, and the pressure is maintained for 15-30 min under 1-5 MPa; and (3) performing pressure relief and bubble removal treatment in the second stage, wherein the hot pressing temperature in the third stage is 160-170 ℃, and the pressure is maintained at 15-20 MPa for 15-20 min.

And further, the water cooling device quickly reduces the temperature of the composite film to room temperature, and the pressure is maintained for 1-5 min under 1-5 MPa to obtain a compact all-organic composite medium with the thickness of about 10-20 microns.

The invention has the beneficial effects that:

the CR-C and CR-S have higher dielectric constants, and the two organic high polymer materials are introduced into the polyvinylidene fluoride, so that the dielectric constant of the polyvinylidene fluoride can be improved, and the polarization performance of the all-organic polymer is improved. By introducing the linear polymer polyimide and the polyether sulfone, the breakdown strength of the polyvinylidene fluoride matrix can be improved, and the insulating property of the polymer-based composite medium can be effectively enhanced. In the experiment, the energy storage performance of the polyvinylidene fluoride is improved respectively from the improvement of the polarization direction and the breakdown direction.

The preparation process and the required equipment are low in price, and the experiment is simple and easy to implement. The all-organic composite medium which is uniformly and compactly distributed and prepared by experiments can effectively improve the energy storage performance of the polymer and maintain the excellent mechanical property of the polymer matrix. Therefore, the all-organic-based composite medium prepared by the experiment can be applied to the field of energy storage.

Drawings

FIG. 1 is a Fourier transform infrared spectrum of an all-organic composite dielectric film;

FIG. 2(a), (b), (c) and (d) are sectional scanning electron micrographs of polyvinylidene fluoride-based composite medium introduced with PI, PESU and CR-C, CR-S in sequence;

FIG. 3 shows a Weibull breakdown distribution of breakdown field strength of the all-organic composite dielectric;

FIG. 4 is a graph of dielectric properties of an all-organic composite medium;

FIG. 5 energy storage performance of all-organic composite medium

Detailed Description

The technical solutions of the present invention are further described below with reference to examples, but not limited thereto, and modifications or equivalent substitutions may be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Example 1

A preparation method and an energy storage performance optimization method of an all-organic composite dielectric medium are characterized in that the all-organic composite dielectric medium is prepared by blending polyvinylidene fluoride substrates with organic polymers such as PI, PESU, CR-C, CR-S and the like respectively.

The preparation and energy storage performance optimization method of the all-organic composite dielectric comprises the following steps:

the method comprises the following steps:

PI, PESU and CR-C, CR-S are placed in a forced air drying oven for heat treatment for 6 hours at the temperature of 60 ℃. Then, sequentially weighing five parts of 1-2 g polyvinylidene fluoride powder by using a digital balance, placing the five parts in a beaker, respectively weighing 10-20 ml of DMF solution by using a pipette, adding dried 0.1-0.5 g of PI, 0.1-0.5 g of PESU, 0.1-0.5 g of CR-C and 0.1-0.5 g of CR-S into DMF, stirring at room temperature until the solutions are completely dissolved, and stirring at room temperature for 12h until the solutions are uniformly dispersed.

Step two:

and (3) putting the precursor solution obtained in the step one into a vacuum drying oven, standing at normal temperature for 2-12 h, and taking out the colloid for later use after bubbles in the precursor solution are completely separated out.

Step three:

wiping a clean glass plate prepared in advance with alcohol, placing the glass plate on an automatic film coating machine after confirming that the surface is smooth, setting the advancing speed of a push knife of the film coating machine to be 3-8 cm/s and the advancing distance of the push knife to be 20-30 cm, taking out the scraper, placing the scraper on the glass plate, leveling the scraper, rotating the spiral scale of the scraper for 10-30 grids, pouring the precursor solution prepared in the second step on the surface of the glass plate, properly inclining the glass plate to enable the precursor solution to flow to the scraper, and then carrying out film coating treatment.

Step four:

and marking the film prepared by the blade coating method according to different doping proportions, transferring the film to a blast drying oven, setting the temperature to be 60-150 ℃ and setting the time to be 4-12 h. And then taking out the glass plate, transferring the glass plate into a vacuum drying box, vacuumizing the vacuum drying box, setting the temperature to be 60-150 ℃, carrying out heat treatment in the vacuum drying box for 12 hours, taking out the glass plate, and tearing off the film by using a blade under the action of deionized water and placing the film in a polyester film for later use.

Step five:

the method comprises the following steps of (1) placing the all-organic composite film in a hot-pressing template by adopting a hot-pressing process, and carrying out gradient heating hot-pressing treatment by hot-pressing treatment: in the first stage, the hot pressing temperature is 100-120 ℃, and the pressure is maintained for 15-30 min under 1-5 MPa; and (3) performing pressure relief and bubble removal treatment in the second stage, wherein the hot pressing temperature in the third stage is 160-170 ℃, and the pressure is maintained at 15-20 MPa for 15-20 min. And then, rapidly cooling the temperature of the composite film to room temperature through a water cooling device, and maintaining the pressure for 1-5 min under 1-5 MPa to obtain a compact all-organic composite medium with the thickness of about 10-20 microns.

Example 2

A preparation method and an energy storage performance optimization method of an all-organic composite dielectric medium are characterized in that the all-organic composite dielectric medium is prepared by blending polyvinylidene fluoride substrates with organic polymers such as PI, PESU, CR-C, CR-S and the like respectively.

The preparation and energy storage performance optimization method of the all-organic composite dielectric comprises the following steps:

the method comprises the following steps:

PI, PESU and CR-C, CR-S are placed in a forced air drying oven for heat treatment for 6 hours at the temperature of 60 ℃. Then, five parts of 1.9g polyvinylidene fluoride powder are sequentially weighed by a digital balance and placed in a beaker, 20ml of DMF solution is respectively weighed by a pipette and added into the beaker, and dried 0.1g of PI, 0.1g of PESU, 0.1g of 0.1gCR-C and 0.1g of CR-S are respectively and sequentially added into DMF and stirred at room temperature until the solution is completely dissolved, and stirred at normal temperature for 12 hours until the solution is uniformly dispersed.

Step two:

and (3) putting the precursor solution obtained in the step one into a vacuum drying oven, standing for 2 hours at normal temperature, and taking out the colloid for later use after bubbles in the precursor solution are completely separated out.

Step three:

wiping a clean glass plate prepared in advance with alcohol, placing the glass plate on an automatic film coating machine after confirming that the surface is smooth, setting the advancing speed of a push knife of the film coating machine to be 4cm/s and the advancing distance of the push knife to be 20cm, taking out the push knife and placing the push knife on the glass plate, leveling the push knife, rotating the spiral scale of the push knife for 25 grids, pouring the precursor solution prepared in the second step on the surface of the glass plate, properly inclining the glass plate to enable the precursor solution to flow to the position of the push knife, and then carrying out film coating treatment.

Step four:

the films prepared by the blade coating method are marked according to different doping proportions and transferred into an air-blast drying oven, the temperature is set to be 80 ℃, and the time is set to be 12 hours. And then taking out the glass plate, transferring the glass plate into a vacuum drying oven, vacuumizing the vacuum drying oven, setting the temperature to be 80 ℃, taking out the glass plate after heat treatment for 12 hours in the vacuum drying oven, and tearing off the film and putting the film in a polyester film for later use by using a blade under the action of deionized water.

Step five:

the method comprises the following steps of (1) placing the all-organic composite film in a hot-pressing template by adopting a hot-pressing process, and carrying out gradient heating hot-pressing treatment by hot-pressing treatment: the hot pressing temperature of the first stage is 100 ℃, and the pressure is maintained for 20min under 5 MPa; and the second stage is used for pressure relief and bubble removal treatment, and the third stage is used for maintaining the pressure at the temperature of 150 ℃ and the pressure at 15MPa for 15 min. And then, rapidly cooling the temperature of the composite film to room temperature through a water cooling device, and maintaining the pressure for 5min at 5MPa to obtain a compact all-organic composite medium with the thickness of about 10 microns.

The Fourier infrared spectrum of the all-organic composite medium obtained in the experiment is shown in figure 1, and the observation of the Fourier infrared spectrum shows that the CR-C doped PVDF has the Fourier infrared spectrum of 2254cm^-1There is a band corresponding to the stretching vibration of the C.ident.N group, confirming the introduction of CR-C and CR-S, while in the spectrum of the doped polyimide, it is also at 1776cm, respectively^-1C-O asymmetric stretching vibration and 1733cm^-1And C is symmetrical stretching vibration of O. In the images incorporating polyethersulfone, also 1579, 1487cm, respectively^-1A benzene ring framework vibration peak is found, the characteristic peak represents the structural characteristics of the polyether sulfone, and the successful preparation of the all-organic composite medium is shown.

FIG. 2 is a scanning electron microscope image of a cross section of the all-organic composite medium, according to the SEM image, the thickness of the all-organic composite medium single-layer film is uniform and is about 10 μm, meanwhile, each organic polymer and polyvinylidene fluoride have good compatibility, no large-area agglomeration phenomenon is found, the cross section is smooth, and no obvious macroscopic defects such as holes, cracks and the like are observed.

FIG. 3 is a Weibull distribution diagram of dielectric breakdown strength of all-organic composite dielectric. As can be seen from the figure, the breakdown strength is slightly reduced after a small amount of organic composite dielectric is doped, but after 5 wt.% of polyimide is doped, the β is 9.8, which indicates that the breakdown stability of the PVDF-based composite dielectric is improved. And the excessive doping amount can cause defects of the composite medium, so that the breakdown field strength is reduced. The range of the characteristic breakdown strength when the cumulative failure probability is 63.2% is 330-500 kV/mm. The high breakdown field strength indicates that the quality of the film is optimized to withstand higher electric field strengths.

FIG. 4 is a diagram of dielectric properties of an all-organic composite medium, and it can be seen that the dielectric constant of the composite medium is improved by introducing a small amount of high molecular polymer such as PI, CR-C, CR-S, etc. compared with pure PVDF medium, which may be due to the higher dielectric constant of the introduced organic polymer itself and the enhancement of interface polarization. Under the frequency of 1Hz, the dielectric constant of the all-organic composite medium ranges from 8.8 to 10.2, and the dielectric loss ranges from 0.10 to 0.15. At 1X 10⁷Under the frequency of Hz, the dielectric constant of the all-organic composite medium ranges from 4 to 6, and the dielectric loss ranges from 0.13 to 0.23.

FIG. 5 is a diagram showing the energy storage performance of an all-organic composite medium, wherein 5 wt.% of PI, PESU and CR-C, CR-S are introduced into PVDF, and the energy density is within the range of 2.4-2.8J/cm under the electric field strength of 200kV/mm³The range of the charge and discharge efficiency is 60 to 70 percent. The discharge energy density range is 9.5-10.8J/cm under the electric field intensity of 400kV/mm³The range of the charge and discharge efficiency is 43 to 54 percent. Incorporation of 5 wt.% polyimide [ PI ]]The result shows that the discharge energy density can reach 10.8J/cm under the electric field intensity of 400kV/mm³The charge-discharge efficiency was 47.5%. The film has excellent energy storage performance on the basis of excellent dielectric and breakdown-resistant field strength.

It can be seen from fig. 3, 4 and 5 that the preparation method of the invention can make the prepared all-organic composite medium based on the ferroelectric polymer polyvinylidene fluoride have higher dielectric constant and breakdown strength. According to the invention, the full organic composite medium is introduced into the polyvinylidene fluoride, so that the discharge energy density of the polymer-based composite medium is improved, and the energy storage performance of the polyvinylidene fluoride is improved by introducing the low-content organic polymer on the premise of ensuring the good flexibility of the polymer matrix.