Preparation method of one-dimensional double-doped barium titanate ceramic filler PVDF-based composite material
By preparing a double-doped barium titanate ceramic precursor and combining it with electrospinning, a one-dimensional double-doped barium titanate ceramic filler PVDF-based composite material was prepared. This solved the problem of the influence of ceramic filler morphology and doping mode on dielectric and mechanical properties, improved dielectric properties and breakdown strength, and is suitable for energy storage.
Patent Information
- Application Number
- CN202511025645.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-24
- Publication Date
- 2025-10-31
AI Technical Summary
In existing polymer-based composite materials, the morphology and doping method of ceramic fillers affect dielectric and mechanical properties. How to prepare ceramic fillers with suitable morphology to improve energy storage performance and avoid the decline in mechanical properties and increase in void defects caused by excessive content is an urgent problem to be solved.
By preparing a double-doped barium titanate ceramic (xBST-(1-x)BZT) precursor, a double-doped barium titanate nanofiber membrane was prepared by electrospinning and dispersed into ceramic nanorods, which were then blended with PVDF to form a one-dimensional double-doped barium titanate ceramic filler PVDF-based composite material.
It improves the dielectric properties and breakdown strength at room temperature, enhances the overall performance of the composite material, meets the application requirements in the energy storage field, and reduces the negative impact of the filling ratio on mechanical properties.
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Figure CN120865658A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of dielectric materials technology, and particularly relates to a method for preparing a one-dimensional double-doped barium titanate ceramic filler PVDF-based composite material. Background Technology
[0002] Polymer-based composite materials combine the advantages of inorganic and organic materials to a certain extent. Inorganic non-metallic ceramics have both high polarization ability and poor mechanical properties and breakdown strength, while polymers have a certain degree of flexibility and high breakdown strength. Combining the two can achieve a 1+1 effect, resulting in good processability and high dielectric and breakdown performance.
[0003] Research on barium titanate-based ceramics has a history of over seventy years. Barium titanate-based ceramics have a perovskite structure, which is octahedral in shape. 2+ Occupying a cubic lattice vertex (A-site), Ti 4+ Located at the center of the body (B position), O 2 Located at the face center. Below the Curie temperature, the perovskite structure transforms from a cubic phase to a tetragonal phase with relatively low symmetry. At low temperatures, structural distortion occurs, resulting in a tetragonal phase that deviates from the ideal structure and exhibits ferroelectric, piezoelectric, and photoelectric properties. A common modification method for barium titanate-based ceramics is the introduction of other ions, categorized as A-site and B-site based on their placement. Simultaneous doping at both A-site and B-site is also a common control method. The doping elements work together on the lattice, allowing for micro-tuning that alters the dipole moment, thereby affecting the dielectric peak width and Curie temperature, and ultimately improving the dielectric properties at room temperature.
[0004] In addition, the morphology of ceramic fillers in polymer-based composites is also crucial. How to prepare ceramic fillers with suitable morphology to increase the interface between ceramic fillers and polymers and improve the energy storage performance of polymer-based composites; reducing the filling ratio to avoid the decline in mechanical properties and increase in void defects caused by excessive content, and improving the breakdown strength are also urgent problems to be solved.
[0005] In view of the above, this application is hereby submitted. Summary of the Invention
[0006] The purpose of this invention is to provide a method for preparing a one-dimensional double-doped barium titanate ceramic filler PVDF-based composite material. The method involves preparing a double-doped barium titanate ceramic (xBST-(1-x)BZT) precursor, followed by electrospinning to obtain a double-doped barium titanate nanofiber membrane, which is then dispersed into ceramic nanorods and blended with PVDF to obtain the composite material. This composite material possesses high comprehensive performance and shows significant application potential in the energy storage field.
[0007] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is as follows:
[0008] A method for preparing a one-dimensional double-doped barium titanate ceramic filler PVDF-based composite material includes the following steps:
[0009] S1: Tetrabutyl titanate and zirconium acetylacetonate are mixed evenly with an organic solvent to form solution A, and barium acetate and strontium acetate are mixed evenly with deionized water to form solution B.
[0010] Further, the molar ratio of tetrabutyl titanate, zirconium acetylacetonate, barium acetate and strontium acetate is (1-0.8):(0.2-0.7):(0.67-1):(0.33-0).
[0011] Optionally, the organic solvent includes ethanol, etc., and the amount of organic solvent added is sufficient to dissolve tetrabutyl titanate and zirconium acetylacetonate. The amount of deionized water added, 25-35 ml, is also sufficient to dissolve barium acetate and strontium acetate.
[0012] Preferably, acetylacetone is also added to solution A, wherein the molar amount of acetylacetone is 0.5-3% of zirconium acetylacetone.
[0013] More preferably, after adding acetylacetone, the solution A system is heated and stirred at 40-60°C for 0.5-1 h.
[0014] S2: Slowly add solution B to solution A, allowing the reaction to proceed gradually. After the reaction is complete, allow it to age to obtain a wet gel-like ceramic precursor.
[0015] Preferably, when solution B is slowly added to solution A, the mixture is heated and stirred at 40-60°C for 4-6 hours.
[0016] Furthermore, the aging process lasts for 12-18 hours.
[0017] S3: The ceramic precursor is thickened and then electrospinned to prepare a nanofiber membrane.
[0018] Further, the thickening is achieved by adding 5-10% by mass of polyvinylpyrrolidone (PVP) to the ceramic precursor while heating to 35-45°C and stirring for 3-5 hours.
[0019] Furthermore, the voltage conditions for electrospinning are 10-20kV, the distance between the needle and the roller is 20-25cm, and the liquid delivery speed is 0.5-1.5ml / h.
[0020] S4: The nanofiber membrane is calcined and then broken down into nanorods.
[0021] Furthermore, the calcination temperature is 700-900℃, the heating rate is 1-2℃ / min, and the calcination time is 0.5-1h.
[0022] Furthermore, the dispersing is achieved by dispersing the nanofiber membrane using a homogenizing emulsifier at 5000-10000 rpm.
[0023] S5: The nanorods and PVDF are mixed in an organic solvent, dispersed into a suspension by ultrasonic vibration, heated and stirred, and then cast and hot-pressed to obtain the composite material.
[0024] The mass ratio of the nanorods to PVDF is 1:(0.8-1.2);
[0025] And / or, the heating and stirring temperature is 70-90℃; the casting and hot pressing temperature is 150-180℃, and the pressure is 1MPa.
[0026] Compared with the prior art, the present invention has the following beneficial effects:
[0027] This invention prepares a double-doped barium titanate ceramic precursor by mixing solutions of different systems, introducing Sr and Zr elements, and then using electrospinning to prepare a double-doped barium titanate nanofiber membrane, which is subsequently dispersed into ceramic nanorods. This process achieves uniform doping and improves the dielectric properties of barium titanate-based ceramics at room temperature. Blending with PVDF yields a composite material, enhancing its overall performance and meeting the application requirements in energy storage. Simultaneously, introducing a 1D high aspect ratio ceramic filler helps increase the interface between the ceramic filler and the polymer, improving the energy storage performance of the polymer-based composite material; reducing the filler ratio avoids the decrease in mechanical properties and increase in porosity defects caused by excessive content, thus improving the breakdown strength. Attached Figure Description
[0028] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope of the present invention.
[0029] Figure 1 This is a comparison diagram of the dielectric constants of the ceramic precursor of Example 1 of this application and the ceramic synthesized from barium titanate and Comparative Example 1.
[0030] Figure 2 This is a comparison diagram of the dielectric constants of the ceramic precursor of Example 1 and the ceramic synthesized in Comparative Example 2;
[0031] Figure 3 This is a comparison diagram of the dielectric constant of the ceramic precursor of Example 1 and the ceramic synthesized in Comparative Example 3;
[0032] Figure 4 These are the XRD patterns of the ceramic nanorods synthesized in Examples 1-6 of this application;
[0033] Figure 5 This is a SEM image of the ceramic nanorods synthesized in Example 1 of this application;
[0034] Figure 6 This is a SEM image of the one-dimensional double-doped barium titanate ceramic filler PVDF-based composite material synthesized in Example 1 of this application;
[0035] Figure 7 These are breakdown strength images of the one-dimensional double-doped barium titanate ceramic filler PVDF-based composite material synthesized in Examples 1 and 2 of this application and the 0D double-doped barium titanate ceramic filler PVDF-based composite material of Comparative Example 4. Detailed Implementation
[0036] To make the technical problem to be solved, the technical solution, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. Material ratios not shown in the embodiments or comparative examples of the present invention can be any ratio, and ratios without specified units are mass ratios.
[0037] The breakdown strength in the embodiment was tested using a continuous rapid voltage ramp test method, with a ramp rate of 0.5-1kV / s, a peak drop voltage of 5kV, and a termination voltage of 50kV.
[0038] The following description is based on specific embodiments.
[0039] Example 1
[0040] A method for preparing a one-dimensional double-doped barium titanate ceramic filler PVDF-based composite material:
[0041] (1) Tetrabutyl titanate, zirconium acetylacetonate, barium acetate, and strontium acetate were prepared in a molar ratio of 0.8:0.2:0.67:0.33. Tetrabutyl titanate and zirconium acetylacetonate were dissolved in ethanol, and acetylacetonate (1% of the molar amount of zirconium acetylacetonate) was added. The mixture was heated and stirred at 45°C for 1 hour to obtain solution A. Barium acetate and strontium acetate were dissolved in deionized water to obtain solution B. Solution B was added dropwise to solution A, and the mixture was heated and stirred at 45°C for 5 hours to allow the reaction to proceed gradually. After aging for 15 hours, a wet gel-like ceramic precursor was obtained. Its dielectric constant was compared with that of the ceramics in Comparative Examples 1-3 below as follows: Figure 1 , Figure 2 and Figure 3 As shown.
[0042] (2) 5% polyvinylpyrrolidone (PVP) was added to the obtained ceramic precursor, and the mixture was heated to 40°C and stirred for 4 hours to obtain a spinning solution. The spinning solution was then used to obtain nanofiber membranes via electrospinning. The electrospinning voltage was 15 kV, the distance between the needle and the roller was 20 cm, and the feed rate was 1 ml / h. The obtained nanofiber membranes were calcined at 800°C with a heating rate of 1.5°C / min and a holding time of 1 hour. After cooling, the membranes were homogenized into ceramic nanorods using a homogenizer at 8000 rpm. Their XRD and SEM images were obtained respectively. Figure 4 and Figure 5 As shown.
[0043] (3) The obtained ceramic nanorods and PVDF were blended at a mass ratio of 1:1 and dispersed into a suspension by ultrasonic vibration in N,N-dimethylformamide. The suspension was heated and stirred at 80°C, and then the composite material was obtained by casting hot pressing at 160°C and 1MPa. Figure 6 Its SEM image is shown; Figure 7 An image of its breakdown strength is shown.
[0044] Example 2
[0045] The difference from Example 1 is that the molar ratio of tetrabutyl titanate, zirconium acetylacetonate, barium acetate, and strontium acetate is 0.7:0.3:0.67:0.33, and the molar amount of acetylacetonate added is 0.5% of the zirconium acetylacetonate. The XRD pattern of its ceramic nanorods is shown below. Figure 4 As shown.
[0046] Example 3
[0047] The difference from Example 1 is that the molar ratio of tetrabutyl titanate, zirconium acetylacetonate, barium acetate, and strontium acetate is 0.6:0.4:0.67:0.33, and the molar amount of acetylacetonate added is 3% of the zirconium acetylacetonate. The XRD pattern of its ceramic nanorods is shown below. Figure 4 As shown.
[0048] Example 4
[0049] The difference from Example 1 is that the molar ratio of tetrabutyl titanate, zirconium acetylacetonate, barium acetate, and strontium acetate is 0.5:0.5:0.67:0.33, and solution A is heated and stirred at 40°C for 1 hour. The XRD pattern of its ceramic nanorods is shown below. Figure 4 As shown.
[0050] Example 5
[0051] The difference from Example 1 is that the molar ratio of tetrabutyl titanate, zirconium acetylacetonate, barium acetate, and strontium acetate is 0.4:0.6:0.75:0.25, and solution A is heated and stirred at 50°C for 1 hour. The XRD pattern of its ceramic nanorods is shown below. Figure 4 As shown.
[0052] Example 6
[0053] The difference from Example 1 is that the molar ratio of tetrabutyl titanate, zirconium acetylacetonate, barium acetate, and strontium acetate is 0.3:0.7:0.8:0.2. The XRD pattern of its ceramic nanorods is shown below. Figure 4 As shown.
[0054] Comparative Example 1
[0055] The difference from Example 1 is that strontium acetate was not added in step (1), and the molar ratio of strontium acetate was completely replaced by barium acetate. Its ceramic dielectric constant is as follows: Figure 1 As shown.
[0056] Comparative Example 2
[0057] The difference from Example 1 is that in step (1), solution A was not heated and stirred at 45°C. Its ceramic dielectric constant is as follows: Figure 2 As shown.
[0058] Comparative Example 3
[0059] The difference from Example 1 is that acetylacetone was not added in step (1), and its ceramic dielectric constant is as follows: Figure 3 As shown.
[0060] Comparative Example 4
[0061] To prepare 0D ceramic filler / PVDF composite material, the double-doped barium titanate ceramics obtained in Examples 1 and 2 were directly ground to obtain ceramic particles, which were then blended with PVDF at a mass ratio of 1:1. The particles were dispersed into a suspension by ultrasonic vibration in N,N-dimethylformamide, and the suspension was heated and stirred at 80°C. Subsequently, the composite material was obtained by casting hot pressing at 160°C and 1MPa.
[0062] Depend on Figure 1 It was found that the dielectric constant was improved by introducing double-doped barium titanate ceramics compared to both barium titanate and barium zirconium titanate, indicating that the introduction of Sr and Zr elements helps to improve dielectric properties.
[0063] Depend on Figure 2 As can be seen from the comparison diagram of the dielectric constants of the ceramics synthesized in Example 1 and Comparative Example 2, heating and stirring solution A helps to enhance the dielectric properties.
[0064] Depend on Figure 3 As can be seen from the comparison of the dielectric constants of the ceramics synthesized in Example 1 and Comparative Example 3, the addition of acetylacetone resulted in ceramics with better performance. This is related to the fact that acetylacetone inhibits the hydrolysis of tetrabutyl titanate, and the titanium source is not consumed during the hydrolysis process, thus enhancing the dielectric properties.
[0065] Depend on Figure 4 It can be seen that the ceramic nanorods of the present invention exhibit a distinct perovskite structure, and as x increases in the double-doped barium titanate ceramic (xBST-(1-x)BZT), the diffraction peaks shift to the left. This is related to the lattice parameters. The reduction of Zr and the increase of Sr will reduce the ionic radius, thereby changing the position of the diffraction peaks. Characterization of the XRD images shows that the doping elements Zr and Sr have been successfully introduced into the lattice.
[0066] Depend on Figure 7 The Weibull distribution diagram shows that, after the introduction of 1D ceramic filler, the breakdown strength is significantly enhanced compared with the 0D double-doped barium titanate ceramic filler PVDF-based composite material in Comparative Example 4.
[0067] The above description is only a preferred embodiment of the present invention and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included within the protection scope of the present application.
Claims
1. A method for preparing a one-dimensional double-doped barium titanate ceramic filler PVDF-based composite material, characterized in that, Includes the following steps: S1: Tetrabutyl titanate and zirconium acetylacetonate are mixed evenly with an organic solvent to form solution A, and barium acetate and strontium acetate are mixed evenly with deionized water to form solution B; S2: Slowly add solution B to solution A, allowing the reaction to proceed gradually. After the reaction is complete, age the solution to obtain a wet gel-like ceramic precursor. S3: Thicken the ceramic precursor and then prepare a nanofiber membrane by electrospinning; S4: The nanofiber membrane is calcined and then broken down into nanorods; S5: The nanorods are mixed with PVDF in an organic solvent, dispersed into a suspension, heated and stirred, and then cast and hot-pressed to obtain the composite material.
2. The preparation method according to claim 1, characterized in that, In step S1, the molar ratio of tetrabutyl titanate, zirconium acetylacetonate, barium acetate and strontium acetate is (1-0.8):(0.2-0.7):(0.67-1):(0.33-0).
3. The preparation method according to claim 1 or 2, characterized in that, In step S1, acetylacetone is also added to solution A, and the molar amount of acetylacetone is 0.5-3% of zirconium acetylacetone.
4. The preparation method according to claim 3, characterized in that, In step S1, after adding acetylacetone, the solution A system is heated and stirred at 40-60℃ for 0.5-1h.
5. The preparation method according to claim 4, characterized in that, In step S2, when solution B is slowly added to solution A, the mixture is heated and stirred at 40-60°C for 4-6 hours. And / or, the aging process is carried out for 12-18 hours.
6. The preparation method according to claim 1, characterized in that, In step S3, the thickening is achieved by adding 5-10% by mass of polyvinylpyrrolidone to the ceramic precursor, while heating to 35-45°C and stirring for 3-5 hours.
7. The preparation method according to claim 1, characterized in that, In step S3, the voltage conditions for electrospinning are 10-20kV, the distance between the needle and the roller is 20-25cm, and the liquid delivery speed is 0.5-1.5ml / h.
8. The preparation method according to claim 1, characterized in that, In step S4, the calcination temperature is 700-900℃ and the calcination time is 0.5-1h.
9. The preparation method according to claim 1, characterized in that, In step S4, the dispersing is to disperse the nanofiber membrane using a homogenizing emulsifier at 5000-10000 rpm.
10. The preparation method according to claim 1, characterized in that, In step S5, the mass ratio of the nanorods to PVDF is 1:(0.8-1.2); And / or, the heating and stirring temperature is 70-90°C.