A high-energy-storage calcium titanate-based dielectric material and its preparation method

Abstract

A calcium titanate-based dielectric material with high energy storage performance was designed. The chemical formula of this material is Ca. 1‑x Dy x (Ti 1‑y Hf y ) 1‑x / 4 O3-z mol%M, where x=0.005~0.05, y=0.1~0.2, z=0~2, and M is MnO2 or BaCu(B2O5). It is prepared using solid-state reaction and tape casting methods. This invention, based on calcium titanate-based ceramics with high breakdown field strength, employs a series of strategies to improve energy storage performance, including element substitution, doping with sintering aids, and process improvement: partial substitution of Hf elements at the B site increases the band gap; doping with sintering aids improves grain density, both of which enhance the breakdown field strength; the addition of rare earth element Dy enhances the polarization response by introducing defect dipoles; the non-stoichiometric design reduces oxygen vacancy compensation, thereby increasing resistivity; and the tape casting method improves ceramic density and grain uniformity. The final prepared calcium titanate-based energy storage medium ceramic material exhibits good energy storage performance, with Ca... 0.995 Dy 0.005 (Ti 0.9 Hf 0.1 ) 0.99875 The best energy storage performance was achieved in O3-0.5 mol% BaCu(B2O5) ceramics, with a breakdown field strength of 101.90 kV / mm and an effective energy storage density of 10.22 J / cm³. 3 .

Description

Technical Field

[0001] This invention belongs to the field of electronic information functional materials and devices technology, specifically designing a high-energy-storage calcium titanate-based dielectric material and its preparation method. Background Technology

[0002] Currently, the contradiction between energy demand and environmental protection is becoming increasingly prominent, prompting the world to enter a new stage of sustainable development. Especially in key sectors such as manufacturing, defense, energy, and healthcare, the demand for new, high-efficiency, and high-power technologies is growing rapidly. Against this backdrop, pulsed power technology, with its advantages of high application voltage, short pulse width, and ultra-high power, is widely used. Among these, energy storage systems play a crucial role. Pulse energy storage systems include mechanical, chemical, inductive, and capacitive energy storage, each with its own advantages and disadvantages in terms of energy density, power density, and other energy storage indicators. Dielectric capacitors, with their advantages of extremely short charging time, high power density, and high operating voltage, show promising prospects. High energy density is required for dielectric capacitors, and energy density is mainly related to polarization intensity and breakdown field strength; therefore, methods to improve polarization intensity and breakdown field strength need to be studied. Furthermore, the application environment of pulsed power technology is complex, and it also has high requirements for performance such as temperature stability and fatigue resistance. To meet the above requirements, calcium titanate was selected as the matrix, and a product with the chemical formula Ca was designed. 1-x Dy x (Ti 1- y Hf y ) 1-x / 4O3-z mol%M (M is MnO2 or BaCu(B2O5)) is a perovskite-structured high-energy-storage calcium titanate-based dielectric material. Calcium titanate, as a paraelectric perovskite material, exhibits low dielectric loss, a large bandgap, and consequently, a high intrinsic breakdown field strength. However, its inherently low dielectric constant leads to a relatively low effective energy storage density. Building upon the high intrinsic breakdown field strength of calcium titanate, a series of strategies, including elemental substitution, doping with sintering aids, and process improvements, are employed to further enhance its breakdown field strength, stability, and fatigue resistance, resulting in pulse capacitors with superior energy storage performance and the ability to be applied in more complex environments. The strategy is as follows: partial substitution of Ti with Hf at the B-site of the perovskite structure can improve the band gap, while doping with sintering aids improves grain density, both of which can further enhance the breakdown field strength; appropriate addition of rare earth element Dy can enhance the polarization response by introducing defect dipoles and can effectively refine the grains, thus improving energy storage performance; a non-stoichiometric design is adopted to compensate for charge with B-site vacancies, reduce oxygen vacancy compensation, and regulate the lattice structure to introduce local disorder, thereby improving resistivity and polarization response; ceramic samples are prepared by tape casting, which has higher density, uniformity, and lower defect concentration compared to conventional bulk samples, thus improving energy storage performance. Summary of the Invention

[0003] The purpose of this invention is to address the current demand for high-energy-storage capacitors by proposing a calcium titanate-based dielectric material with high energy storage performance and its preparation method. Based on calcium titanate-based ceramics with high breakdown field strength, a series of strategies, including element substitution, doping with sintering aids, and process improvement, are employed to enhance energy storage performance. Ultimately, excellent energy storage performance is achieved: the optimal energy storage formula achieves a breakdown field strength of 101.90 kV / mm and an effective energy storage density of 10.22 J / cm². 3 . To achieve the above objectives, the technical solution adopted by the present invention is as follows: A calcium titanate-based dielectric material with high energy storage performance, its chemical composition is expressed as Ca. 1-x Dy x (Ti 1- y Hf y ) 1-x / 4 O3-z mol%M, where x=0.005~0.05, y=0.1~0.2, z=0.5~2, and M is MnO2 or BaCu(B2O5). Furthermore, the optimal energy storage performance formulation of the aforementioned dielectric material achieves a breakdown field strength of 101.90 kV / mm and an effective energy storage density of 10.22 J / cm². 3 . Furthermore, the aforementioned medium material is prepared using CaTiO3, TiO2, HfO2, Dy2O3, MnO2, BaCO3, CuO, and B2O3 as raw materials according to the chemical composition expression. The main steps of the above-mentioned method for preparing the dielectric material are as follows: (1) Using CaTiO3, TiO2, HfO2, and Dy2O3 as raw materials, according to the chemical composition expression Ca 1-x Dy x (Ti 1-y Hf y ) 1-x / Weigh and prepare 4O3 materials, where x = 0.005~0.05 and y = 0.1~0.2. After weighing, pour the mixture into a ball mill jar, with the weight ratio of powder, alcohol, and zirconium balls being 1:1.5:6. Ball mill for 12 hours, then remove and dry in an oven at 85 ℃ for 4 hours. Grind again and pass through a 120-mesh sieve. Then, pour the powder into a crucible, compact it, pre-calcine it in a sintering furnace at 1200 ℃ for 4 hours, and grind it again to pass through a 120-mesh sieve to obtain powder A. (2) Using BaCO3, CuO, and B2O3 as raw materials, the materials were weighed and prepared according to the chemical composition formula BaCu(B2O5). After weighing, the materials were poured into a ball mill jar, where the weight ratio of the medium powder, alcohol, and zirconium balls was 1:1.5:6. The materials were ball-milled for 8 hours, then dried, ground, and passed through a 120-mesh sieve. The powder was then poured into a crucible and calcined in a sintering furnace at 700 °C for 3 hours. After grinding, the powder was passed through a 120-mesh sieve to obtain powder B. (3) Powder A and powder B obtained in steps (1) and (2) are combined according to the chemical composition expression Ca 1-x Dy x (Ti 1- y Hf y ) 1-x / 4 The O3-z mol%M was weighed and mixed, where x = 0.005~0.05, y = 0.1~0.2, z = 0~2, and M is MnO2 or BaCu(B2O5). Then, a second ball milling was performed, with the weight ratio of powder, alcohol, and zirconium balls being 1:1.5:6. The mixture was ball-milled for 12 hours, then dried, ground, and passed through a 120-mesh sieve to obtain powder C. (4) Pour the powder C obtained in step (3) into a ball mill jar, add zirconium balls, alcohol, toluene, tributyl phosphate, o-xylene, PVB and defoamer in a certain proportion, and then ball mill for 12 h. After taking it out, sieve it to obtain slurry. (5) Pour the slurry obtained in step (4) into the material receiving tank of the coating machine, and then start the push rod to coat the slurry evenly to form a ceramic film on the PET film. The coating speed is 15 mm / s and the doctor blade height is 20 μm. After coating, place it in the air to dry. Then cut the ceramic film to the required size, stack it, and put it into a hot press for hot pressing. The pressure is 10 MPa, and it is kept at 80℃ for 1 h. After cutting, the green film is obtained. (6) Remove the binder from the green body obtained in step (5), hold it at 550 ℃ for 5 h in an electric furnace, then raise the temperature to 1000 ℃ and hold it for 0.5 h. Then sinter it in a sintering furnace at 1400~1450 ℃ for 4 h, and then let it cool naturally. The medium material is obtained. This invention provides a calcium titanate-based dielectric material with high energy storage performance, having the chemical formula Ca. 1-x Dy x (Ti 1- y Hf y ) 1-x / 4 O3-z mol%M (M is MnO2 or BaCu(B2O5)). Based on calcium titanate-based ceramics with high breakdown field strength, a series of strategies, including element substitution, doping with sintering aids, and process improvement, are adopted to enhance energy storage performance. Partial substitution of Hf elements at the B site can improve the band gap, and doping with sintering aids can improve grain density, both of which can improve the breakdown field strength; the addition of rare earth element Dy enhances the polarization response by introducing defect dipoles; the non-stoichiometric design reduces oxygen vacancy compensation and improves resistivity; the casting method is used to improve density and uniformity. The dielectric ceramic material obtained by this invention has good energy storage performance, especially in Ca2+. 0.995 Dy 0.005 (Ti 0.9 Hf 0.1 ) 0.99875 The best energy storage performance was achieved in O3-0.5 mol% BaCu(B2O5) ceramics, with a breakdown field strength of 101.90 kV / mm and an effective energy storage density of 10.22 J / cm³. 3 . Compared with the prior art, the present invention has the following beneficial effects: 1. The energy storage medium ceramic material provided by this invention has excellent energy storage performance. In the prior art, research on calcium titanate paraelectric ceramic systems in the field of energy storage ceramics is insufficient, and the addition of sintering aids to calcium titanate systems is even rarer, with energy storage densities mostly limited to 3 J / cm³. 3 Within this range. The breakdown field strength of the energy storage medium ceramic of this invention is between 39.96 and 101.90 kV / mm, and the effective energy storage density is between 1.34 and 10.22 J / cm³. 3 Between these, most components have achieved significant performance improvements. In Ca...0.995 Dy 0.005 (Ti 0.9 Hf 0.1 ) 0.99875 O3 The best energy storage performance was achieved in 0.5 mol% BaCu(B₂O₅) ceramics, with a breakdown field strength of 101.90 kV / mm and an effective energy storage density of 10.22 J / cm³. 3 . 2. The energy storage medium ceramic material of this invention employs a non-stoichiometric ratio. By designing B-site vacancies to compensate for the charge brought by Dy ions, and minimizing oxygen vacancies or Ti ion valence changes for compensation, resistivity is increased, which in turn benefits the breakdown field strength. Furthermore, B-site vacancies modulate the oxygen octahedral structure, increasing local disorder and thus enhancing the polarization response and polarization intensity. Both increased breakdown field strength and polarization intensity contribute to improved energy storage density. 3. The energy storage medium ceramic material of this invention adopts the casting method. Compared with conventional bulk materials, the ceramic film prepared by the casting method has higher density, uniformity and lower defect concentration. Therefore, the breakdown field strength of the ceramic film prepared by the casting method is generally higher than that of conventional bulk materials, which is beneficial to improving energy storage performance. Attached Figure Description Figure 1 The images show SEM images of the energy storage medium ceramic materials prepared in Examples 1-11. Figure 2 The graph shows the dielectric constant and loss of the energy storage medium ceramic materials prepared in Examples 1 to 11 as a function of temperature (25 to 400 °C) in the frequency range of 1 kHz to 1 MHz. Figure 3 The hysteresis loop of the energy storage medium ceramic materials prepared in Examples 1-11 at 10 Hz is shown. Detailed Implementation To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. The following specific examples illustrate the implementation of this invention, and those skilled in the art can easily understand other advantages and effects of this invention from the content disclosed in this specification. This invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this invention. Example 1 (1) Using CaTiO3, TiO2, HfO2, and Dy2O3 as raw materials, according to the chemical composition expression Ca 0.995 Dy 0.005 (Ti 0.8 Hf 0.8) 0.99875 O3 was weighed and prepared. After weighing, the powder, alcohol, and zirconium balls were poured into a ball mill jar, with a weight ratio of 1:1.5:6. The mixture was ball-milled for 12 hours, then dried in an oven at 85°C for 4 hours, followed by grinding and sieving through a 120-mesh sieve. The powder was then poured into a crucible, compacted, and pre-calcined in a sintering furnace at 1200°C for 4 hours. Finally, it was ground and sieved through a 120-mesh sieve to obtain the final powder. (2) The powder obtained in step (1) is subjected to secondary ball milling, wherein the weight ratio of powder, alcohol and zirconium balls is 1:1.5:6. The powder is ball-milled for 12 hours, then dried, ground and passed through a 120-mesh sieve to obtain powder. (3) Pour the powder C obtained in step (2) into a ball mill jar, add zirconium balls, alcohol, toluene, tributyl phosphate, o-xylene, PVB and defoamer in a certain proportion, and then ball mill for 12 h. After taking it out, sieve it to obtain slurry. (4) Pour the slurry obtained in step (3) into the material receiving tank of the coating machine, and then start the push rod to coat the slurry evenly to form a ceramic film on the PET film. The coating speed is 15 mm / s and the doctor blade height is 20 μm. After coating, place it in the air to dry. Then cut the ceramic film to the required size, stack it, and put it into a hot press for hot pressing. The pressure is 10 MPa, and it is kept at 80℃ for 1 h. After cutting, the green film is obtained. (5) Remove the binder from the green body obtained in step (4), heat it in an electric furnace at 550 ℃ for 5 h, then raise the temperature to 1000 ℃ and heat it for 0.5 h. Then sinter it in a sintering furnace at 1450 ℃ for 4 h, and then cool it naturally. The medium material is obtained. The dielectric material prepared in Example 1 was tested using a scanning electron microscope (SEM). Gold plating was required before testing. The results are as follows: Figure 1 As shown in -a, the magnification is 8100 times, the grain boundaries are clear, the density is good, and the average grain size is 9.24 μm. The dielectric properties of the dielectric material prepared in Example 1 were tested, and it needed to be coated with a silver electrode before testing. The results are as follows: Figure 2 As shown in -a, the dielectric constant is 160 and the dielectric loss is 0.002 at room temperature. As the temperature increases, the dielectric constant decreases slightly and the dielectric loss increases. The dielectric material prepared in Example 1 was subjected to ferroelectric property testing. Prior to the test, it required polishing and thinning, and gold-plated electrodes. The results are as follows: Figure 3 As shown, this is a thin hysteresis loop with a breakdown electric field of 79.95 kV / mm and a maximum polarization of 15.89 μC / cm. 2 The remanent polarization intensity is 0.51 μC / cm. 2 The effective energy storage density was calculated to be 5.67 J / cm³ using the energy storage formula.3 The total energy storage density is 6.10 J / cm³. 3 The energy storage efficiency is 92.9%. Example 2 (1) Using CaTiO3, TiO2, HfO2, and Dy2O3 as raw materials, according to the chemical composition expression Ca 0.99 Dy 0.01 (Ti 0.8 Hf 0.2 ) 0.9975 O3 was weighed and prepared. After weighing, the powder, alcohol, and zirconium balls were poured into a ball mill jar, with a weight ratio of 1:1.5:6. The mixture was ball-milled for 12 hours, then dried in an oven at 85°C for 4 hours, followed by grinding and sieving through a 120-mesh sieve. The powder was then poured into a crucible, compacted, and pre-calcined in a sintering furnace at 1200°C for 4 hours. Finally, it was ground and sieved through a 120-mesh sieve to obtain the final powder. (2) The powder obtained in step (1) is subjected to secondary ball milling, wherein the weight ratio of powder, alcohol and zirconium balls is 1:1.5:6. The powder is ball-milled for 12 hours, then dried, ground and passed through a 120-mesh sieve to obtain powder. (3) Pour the powder C obtained in step (2) into a ball mill jar, add zirconium balls, alcohol, toluene, tributyl phosphate, o-xylene, PVB and defoamer in a certain proportion, and then ball mill for 12 h. After taking it out, sieve it to obtain slurry. (4) Pour the slurry obtained in step (3) into the material receiving tank of the coating machine, and then start the push rod to coat the slurry evenly to form a ceramic film on the PET film. The coating speed is 15 mm / s and the doctor blade height is 20 μm. After coating, place it in the air to dry. Then cut the ceramic film to the required size, stack it, and put it into a hot press for hot pressing. The pressure is 10 MPa, and it is kept at 80℃ for 1 h. After cutting, the green film is obtained. (5) Remove the binder from the green body obtained in step (4), heat it in an electric furnace at 550 ℃ for 5 h, then raise the temperature to 1000 ℃ and heat it for 0.5 h. Then sinter it in a sintering furnace at 1450 ℃ for 4 h, and then cool it naturally. The medium material is obtained. The dielectric material prepared in Example 2 was tested using a scanning electron microscope (SEM). Gold plating was required before testing. The results are as follows: Figure 1 As shown in -b, the magnification is 8100 times, the grain boundaries are clear, the density is very good, and the average grain size is 9.56 μm. The dielectric properties of the dielectric material prepared in Example 2 were tested, and it needed to be coated with a silver electrode before testing. The results are as follows: Figure 2 As shown in -b, the dielectric constant is 153 and the dielectric loss is 0.002 at room temperature. As the temperature increases, the dielectric constant decreases slightly and the dielectric loss increases. The dielectric material prepared in Example 3 was subjected to ferroelectric performance testing. Prior to the test, it required polishing and thinning, and gold-plated electrodes. The results are as follows: Figure 3 As shown, this is a thin hysteresis loop with a breakdown field strength of 49.96 kV / mm and a maximum polarization of 9.74 μC / cm. 2 The remanent polarization intensity is 0.41 μC / cm. 2 The effective energy storage density, calculated using the energy storage formula, is 2.25 J / cm³. 3 The total energy storage density is 2.45 J / cm³. 3 The energy storage efficiency is 91.7%. Example 3 (1) Using CaTiO3, TiO2, HfO2, and Dy2O3 as raw materials, according to the chemical composition expression Ca 0.98 Dy 0.02 (Ti 0.8 Hf 0.2 ) 0.995 O3 was weighed and prepared. After weighing, the powder, alcohol, and zirconium balls were poured into a ball mill jar, with a weight ratio of 1:1.5:6. The mixture was ball-milled for 12 hours, then dried in an oven at 85°C for 4 hours, followed by grinding and sieving through a 120-mesh sieve. The powder was then poured into a crucible, compacted, and pre-calcined in a sintering furnace at 1200°C for 4 hours. Finally, it was ground and sieved through a 120-mesh sieve to obtain the final powder. (2) The powder obtained in step (1) is subjected to secondary ball milling, wherein the weight ratio of powder, alcohol and zirconium balls is 1:1.5:6. The powder is ball-milled for 12 hours, then dried, ground and passed through a 120-mesh sieve to obtain powder. (3) Pour the powder C obtained in step (2) into a ball mill jar, add zirconium balls, alcohol, toluene, tributyl phosphate, o-xylene, PVB and defoamer in a certain proportion, and then ball mill for 12 h. After taking it out, sieve it to obtain slurry. (4) Pour the slurry obtained in step (3) into the material receiving tank of the coating machine, and then start the push rod to coat the slurry evenly to form a ceramic film on the PET film. The coating speed is 15 mm / s and the doctor blade height is 20 μm. After coating, place it in the air to dry. Then cut the ceramic film to the required size, stack it, and put it into a hot press for hot pressing. The pressure is 10 MPa, and it is kept at 80℃ for 1 h. After cutting, the green film is obtained. (5) Remove the binder from the green body obtained in step (4), heat it in an electric furnace at 550 ℃ for 5 h, then raise the temperature to 1000 ℃ and heat it for 0.5 h. Then sinter it in a sintering furnace at 1450 ℃ for 4 h, and then cool it naturally. The medium material is obtained. The dielectric material prepared in Example 3 was tested using a scanning electron microscope (SEM). Gold plating was required before testing. The results are as follows: Figure 1 As shown in -c, the magnification is 8100 times, the grain boundaries are clear, the density is good, and the average grain size is 1.19 μm. The dielectric properties of the dielectric material prepared in Example 3 were tested, and it needed to be coated with a silver electrode before testing. The results are as follows: Figure 2 As shown in Figure -c, the dielectric constant is 154 and the dielectric loss is 0.003 at room temperature. With increasing temperature, the dielectric constant first decreases and then increases, while the dielectric loss increases. Frequency dispersion occurs; both the dielectric constant and loss decrease with increasing frequency. The dielectric material prepared in Example 3 was subjected to ferroelectric performance testing. Prior to the test, it required polishing and thinning, and gold-plated electrodes. The results are as follows: Figure 3 As shown, this is a thin hysteresis loop with a breakdown field strength of 59.95 kV / mm and a maximum polarization of 10.56 μC / cm. 2 The remanent polarization intensity is 0.25 μC / cm. 2 The effective energy storage density was calculated to be 2.96 J / cm³ using the energy storage formula. 3 The total energy storage density is 3.11 J / cm³. 3 The energy storage efficiency is 95.0%. Example 4 (1) Using CaTiO3, TiO2, HfO2, and Dy2O3 as raw materials, according to the chemical composition expression Ca 0.95 Dy 0.05 (Ti 0.8 Hf 0.2 ) 0.9875 O3 was weighed and prepared. After weighing, the powder, alcohol, and zirconium balls were poured into a ball mill jar, with a weight ratio of 1:1.5:6. The mixture was ball-milled for 12 hours, then dried in an oven at 85°C for 4 hours, followed by grinding and sieving through a 120-mesh sieve. The powder was then poured into a crucible, compacted, and pre-calcined in a sintering furnace at 1200°C for 4 hours. Finally, it was ground and sieved through a 120-mesh sieve to obtain the final powder. (2) The powder obtained in step (1) is subjected to secondary ball milling, wherein the weight ratio of powder, alcohol and zirconium balls is 1:1.5:6. The powder is ball-milled for 12 hours, then dried, ground and passed through a 120-mesh sieve to obtain powder. (3) Pour the powder C obtained in step (2) into a ball mill jar, add zirconium balls, alcohol, toluene, tributyl phosphate, o-xylene, PVB and defoamer in a certain proportion, and then ball mill for 12 h. After taking it out, sieve it to obtain slurry. (4) Pour the slurry obtained in step (3) into the material receiving tank of the coating machine, and then start the push rod to coat the slurry evenly to form a ceramic film on the PET film. The coating speed is 15 mm / s and the doctor blade height is 20 μm. After coating, place it in the air to dry. Then cut the ceramic film to the required size, stack it, and put it into a hot press for hot pressing. The pressure is 10 MPa, and it is kept at 80℃ for 1 h. After cutting, the green film is obtained. (5) Remove the binder from the green body obtained in step (4), heat it in an electric furnace at 550 ℃ for 5 h, then raise the temperature to 1000 ℃ and heat it for 0.5 h. Then sinter it in a sintering furnace at 1450 ℃ for 4 h, and then cool it naturally. The medium material is obtained. The dielectric material prepared in Example 4 was tested using a scanning electron microscope (SEM). Gold plating was required before testing. The results are as follows: Figure 1 As shown in -d, the magnification is 8100 times, the grain boundaries are relatively clear, the density is good, and the average grain size is 2.25 μm. The dielectric properties of the dielectric material prepared in Example 4 were tested, and it needed to be coated with a silver electrode before testing. The results are as follows: Figure 2 As shown in Figure -d, the dielectric constant is 234 at room temperature and 1 kHz, and the dielectric loss is 0.2. With increasing temperature, the dielectric constant increases, while the overall trend of dielectric loss is increasing. Frequency dispersion occurs; with increasing frequency, the dielectric constant decreases, and the loss peak shifts towards higher temperatures. The dielectric material prepared in Example 4 was subjected to ferroelectric performance testing. Prior to the test, it required polishing and thinning, and gold-plated electrodes. The results are as follows: Figure 3 As shown, this is a thin hysteresis loop with a breakdown field strength of 39.96 kV / mm and a maximum polarization of 7.11 μC / cm. 2 The remanent polarization intensity is 0.23 μC / cm. 2 The effective energy storage density was calculated to be 1.34 J / cm³ using the energy storage formula. 3 The total energy storage density is 1.44 J / cm³. 3 The energy storage efficiency is 93.5%. Example 5 (1) Using CaTiO3, TiO2, HfO2, and Dy2O3 as raw materials, according to the chemical composition expression Ca 0.995 Dy 0.005 (Ti 0.9 Hf 0.1 ) 0.99875O3 was weighed and prepared. After weighing, the powder, alcohol, and zirconium balls were poured into a ball mill jar, with a weight ratio of 1:1.5:6. The mixture was ball-milled for 12 hours, then dried in an oven at 85°C for 4 hours, followed by grinding and sieving through a 120-mesh sieve. The powder was then poured into a crucible, compacted, and pre-calcined in a sintering furnace at 1200°C for 4 hours. Finally, it was ground and sieved through a 120-mesh sieve to obtain the final powder. (2) The powder obtained in step (1) is subjected to secondary ball milling, wherein the weight ratio of powder, alcohol and zirconium balls is 1:1.5:6. The powder is ball-milled for 12 hours, then dried, ground and passed through a 120-mesh sieve to obtain powder. (3) Pour the powder C obtained in step (2) into a ball mill jar, add zirconium balls, alcohol, toluene, tributyl phosphate, o-xylene, PVB and defoamer in a certain proportion, and then ball mill for 12 h. After taking it out, sieve it to obtain slurry. (4) Pour the slurry obtained in step (3) into the material receiving tank of the coating machine, and then start the push rod to coat the slurry evenly to form a ceramic film on the PET film. The coating speed is 15 mm / s and the doctor blade height is 20 μm. After coating, place it in the air to dry. Then cut the ceramic film to the required size, stack it, and put it into a hot press for hot pressing. The pressure is 10 MPa, and it is kept at 80℃ for 1 h. After cutting, the green film is obtained. (5) Remove the binder from the green body obtained in step (4), heat it in an electric furnace at 550 ℃ for 5 h, then raise the temperature to 1000 ℃ and heat it for 0.5 h. Then sinter it in a sintering furnace at 1450 ℃ for 4 h, and then cool it naturally. The medium material is obtained. The dielectric material prepared in Example 5 was tested using a scanning electron microscope (SEM). Gold plating was required before testing. The results are as follows: Figure 1 As shown in -e, the magnification is 8100 times, the grain boundaries are relatively clear, the density is good, and the average grain size is 7.17 μm. The dielectric properties of the dielectric material prepared in Example 5 were tested, and it needed to be coated with a silver electrode before testing. The results are as follows: Figure 2 As shown in -e, the dielectric constant is 178 and the dielectric loss is 0.001 at room temperature. As the temperature increases, the dielectric constant decreases slightly and the dielectric loss increases. The dielectric material prepared in Example 5 was subjected to ferroelectric property testing. Prior to the test, it required polishing and thinning, and gold-plated electrodes. The results are as follows: Figure 3 As shown, this is a thin hysteresis loop with a breakdown field strength of 85.92 kV / mm and a maximum polarization of 18.94 μC / cm. 2 The remanent polarization intensity is 0.61 μC / cm. 2 The effective energy storage density, calculated using the energy storage formula, is 7.25 J / cm³. 3The total energy storage density is 7.90 J / cm³. 3 The energy storage efficiency is 91.8%. Example 6 (1) Using CaTiO3, TiO2, HfO2, and Dy2O3 as raw materials, according to the chemical composition expression Ca 0.995 Dy 0.005 (Ti 0.9 Hf 0.1 ) 0.99875 The O3 materials were weighed and poured into a ball mill jar, with the weight ratio of powder, alcohol, and zirconium balls being 1:1.5:6. The mixture was ball-milled for 12 hours, then dried in an oven at 85°C for 4 hours, followed by grinding and sieving through a 120-mesh sieve. The powder was then poured into a crucible, compacted, and pre-calcined in a sintering furnace at 1200°C for 4 hours. Finally, it was ground and sieved through a 120-mesh sieve to obtain the final powder. (2) The powder obtained in step (1) is mixed with MnO2 according to the chemical composition expression Ca 0.995 Dy 0.005 (Ti 0.9 Hf 0.1 ) 0.99875 The O3-0.5 mol% MnO2 mixture was weighed and prepared, and then subjected to a second ball milling process. The weight ratio of powder, alcohol, and zirconium balls was 1:1.5:6. The mixture was ball-milled for 12 hours, then dried, ground, and passed through a 120-mesh sieve to obtain powder. (3) Pour the powder obtained in step (2) into a ball mill jar, add zirconium balls, alcohol, toluene, tributyl phosphate, o-xylene, PVB and defoamer in a certain proportion, and then ball mill for 12 h. After taking it out, sieve it to obtain slurry. (4) Pour the slurry obtained in step (3) into the material receiving tank of the coating machine, and then start the push rod to coat the slurry evenly to form a ceramic film on the PET film. The coating speed is 15 mm / s and the doctor blade height is 20 μm. After coating, place it in the air to dry. Then cut the ceramic film to the required size, stack it, and put it into a hot press for hot pressing. The pressure is 10 MPa, and it is kept at 80℃ for 1 h. After cutting, the green film is obtained. (5) Remove the binder from the green body obtained in step (4), heat it in an electric furnace at 550 ℃ for 5 h, then raise the temperature to 1000 ℃ and heat it for 0.5 h. Then sinter it in a sintering furnace at 1450 ℃ for 4 h, and then cool it naturally. The medium material is obtained. The dielectric material prepared in Example 6 was tested using a scanning electron microscope (SEM). Gold plating was required before testing. The results are as follows: Figure 1 As shown in -f, the magnification is 8100x, the grain boundaries are relatively clear, the density is good, and the average grain size is 10.18 μm. The dielectric properties of the dielectric material prepared in Example 6 were tested, and it needed to be coated with a silver electrode before testing. The results are as follows: Figure 2 As shown in -f, the dielectric constant is 163 and the dielectric loss is 0.002 at room temperature. As the temperature increases, the dielectric constant decreases slightly and the dielectric loss increases. The dielectric material prepared in Example 6 was subjected to ferroelectric property testing. Prior to the test, it needed to be polished and thinned, and gold-plated electrodes were applied. The results are as follows: Figure 3 As shown, this is a relatively "thick" hysteresis loop with a breakdown electric field of 67.93 kV / mm and a maximum polarization of 16.72 μC / cm. 2 The remanent polarization intensity is 2.55 μC / cm. 2 The effective energy storage density was calculated to be 4.36 J / cm³ using the energy storage formula. 3 The total energy storage density is 5.64 J / cm³. 3 The energy storage efficiency is 77.3%. Example 7 (1) Using CaTiO3, TiO2, HfO2, and Dy2O3 as raw materials, according to the chemical composition expression Ca 0.995 Dy 0.005 (Ti 0.9 Hf 0.1 ) 0.99875 The O3 materials were weighed and poured into a ball mill jar, with the weight ratio of powder, alcohol, and zirconium balls being 1:1.5:6. The mixture was ball-milled for 12 hours, then dried in an oven at 85°C for 4 hours, followed by grinding and sieving through a 120-mesh sieve. The powder was then poured into a crucible, compacted, and pre-calcined in a sintering furnace at 1200°C for 4 hours. Finally, it was ground and sieved through a 120-mesh sieve to obtain the final powder. (2) The powder obtained in step (1) is mixed with MnO2 according to the chemical composition expression Ca 0.995 Dy 0.005 (Ti 0.9 Hf 0.1 ) 0.99875 The O3-1 mol% MnO2 was weighed and mixed, and then subjected to a second ball milling, wherein the weight ratio of powder, alcohol and zirconium balls was 1:1.5:6. The mixture was ball-milled for 12 hours, then dried, ground, and passed through a 120-mesh sieve to obtain powder. (3) Pour the powder obtained in step (2) into a ball mill jar, add zirconium balls, alcohol, toluene, tributyl phosphate, o-xylene, PVB and defoamer in a certain proportion, and then ball mill for 12 h. After taking it out, sieve it to obtain slurry. (4) Pour the slurry obtained in step (3) into the material receiving tank of the coating machine, and then start the push rod to coat the slurry evenly to form a ceramic film on the PET film. The coating speed is 15 mm / s and the doctor blade height is 20 μm. After coating, place it in the air to dry. Then cut the ceramic film to the required size, stack it, and put it into a hot press for hot pressing. The pressure is 10 MPa, and it is kept at 80℃ for 1 h. After cutting, the green film is obtained. (5) Remove the binder from the green body obtained in step (4), heat it in an electric furnace at 550 ℃ for 5 h, then raise the temperature to 1000 ℃ and heat it for 0.5 h. Then sinter it in a sintering furnace at 1450 ℃ for 4 h, and then cool it naturally. The medium material is obtained. The dielectric material prepared in Example 7 was tested using a scanning electron microscope (SEM). Gold plating was required before testing. The results are as follows: Figure 1 As shown in -g, the magnification is 8100 times, the grain boundaries are relatively clear, the density is good, and the average grain size is 9.86 μm. The dielectric properties of the dielectric material prepared in Example 7 were tested, and it needed to be coated with a silver electrode before testing. The results are as follows: Figure 2 As shown in -g, the dielectric constant is 166 and the dielectric loss is 0.002 at room temperature. As the temperature increases, the dielectric constant decreases slightly and the dielectric loss increases. The dielectric material prepared in Example 7 was subjected to ferroelectric property testing. Prior to the test, it required polishing and thinning, and gold-plated electrodes. The results are as follows: Figure 3 As shown, this is a thin hysteresis loop with a breakdown field strength of 59.95 kV / mm and a maximum polarization of 12.52 μC / cm. 2 The remanent polarization intensity is 0.24 μC / cm. 2 The effective energy storage density, calculated using the energy storage formula, is 3.51 J / cm³. 3 The total energy storage density is 3.64 J / cm³. 3 The energy storage efficiency is 96.5%. Example 8 (1) Using CaTiO3, TiO2, HfO2, and Dy2O3 as raw materials, according to the chemical composition expression Ca 0.995 Dy 0.005 (Ti 0.9 Hf 0.1 ) 0.99875 The O3 materials were weighed and poured into a ball mill jar, with the weight ratio of powder, alcohol, and zirconium balls being 1:1.5:6. The mixture was ball-milled for 12 hours, then dried in an oven at 85°C for 4 hours, followed by grinding and sieving through a 120-mesh sieve. The powder was then poured into a crucible, compacted, and pre-calcined in a sintering furnace at 1200°C for 4 hours. Finally, it was ground and sieved through a 120-mesh sieve to obtain the final powder. (2) The powder obtained in step (1) is mixed with MnO2 according to the chemical composition expression Ca 0.995 Dy 0.005 (Ti 0.9 Hf 0.1 ) 0.99875 The O3-2 mol% MnO2 was weighed and mixed, and then subjected to a second ball milling, wherein the weight ratio of powder, alcohol and zirconium balls was 1:1.5:6. The mixture was ball-milled for 12 hours, then dried, ground, and passed through a 120-mesh sieve to obtain powder. (3) Pour the powder obtained in step (2) into a ball mill jar, add zirconium balls, alcohol, toluene, tributyl phosphate, o-xylene, PVB and defoamer in a certain proportion, and then ball mill for 12 h. After taking it out, sieve it to obtain slurry. (4) Pour the slurry obtained in step (3) into the material receiving tank of the coating machine, and then start the push rod to coat the slurry evenly to form a ceramic film on the PET film. The coating speed is 15 mm / s and the doctor blade height is 20 μm. After coating, place it in the air to dry. Then cut the ceramic film to the required size, stack it, and put it into a hot press for hot pressing. The pressure is 10 MPa, and it is kept at 80℃ for 1 h. After cutting, the green film is obtained. (5) Remove the binder from the green body obtained in step (4), heat it in an electric furnace at 550 ℃ for 5 h, then raise the temperature to 1000 ℃ and heat it for 0.5 h. Then sinter it in a sintering furnace at 1400 ℃ for 4 h, and then cool it naturally. The medium material is obtained. The dielectric material prepared in Example 8 was tested using a scanning electron microscope (SEM). Gold plating was required before testing. The results are as follows: Figure 1 As shown in -h, the magnification is 8100 times, the grain boundaries are relatively clear, the density is good, and the average grain size is 7.82 μm. The dielectric properties of the dielectric material prepared in Example 8 were tested, and it needed to be coated with a silver electrode before testing. The results are as follows: Figure 2 As shown in -h, the dielectric constant is 159 and the dielectric loss is 0.003 at room temperature. As the temperature increases, the dielectric constant decreases slightly and the dielectric loss increases. The dielectric material prepared in Example 8 was subjected to ferroelectric property testing. Prior to the test, it required polishing and thinning, and gold-plated electrodes. The results are as follows: Figure 3 As shown, this is a "thick" hysteresis loop with a breakdown electric field of 89.92 kV / mm and a maximum polarization of 22.41 μC / cm. 2 The remanent polarization intensity is 4.68 μC / cm. 2 The effective energy storage density, calculated using the energy storage formula, is 6.89 J / cm³. 3 The total energy storage density is 10.06 J / cm³. 3 The energy storage efficiency is 68.5%. Example 9 (1) Using CaTiO3, TiO2, HfO2, and Dy2O3 as raw materials, according to the chemical composition expression Ca 0.995 Dy 0.005 (Ti 0.9 Hf 0.1 ) 0.99875 The O3 materials were weighed and poured into a ball mill jar, with the weight ratio of powder, alcohol, and zirconium balls being 1:1.5:6. The mixture was ball-milled for 12 hours, then dried in an oven at 85°C for 4 hours, followed by grinding and sieving through a 120-mesh sieve. The powder was then poured into a crucible, compacted, and pre-calcined in a sintering furnace at 1200°C for 4 hours. Finally, it was ground and sieved through a 120-mesh sieve to obtain the final powder. (2) Using BaCO3, CuO, and B2O3 as raw materials, the materials were weighed and prepared according to the chemical composition formula BaCu(B2O5). After weighing, the materials were poured into a ball mill jar, where the weight ratio of the medium powder, alcohol, and zirconium balls was 1:1.5:6. The materials were ball-milled for 8 hours, then dried, ground, and passed through a 120-mesh sieve. The powder was then poured into a crucible and calcined in a sintering furnace at 700 °C for 3 hours. After grinding, the powder was passed through a 120-mesh sieve to obtain powder B. (3) Powder A and powder B obtained in steps (1) and (2) are combined according to the chemical composition expression Ca 0.995 Dy 0.005 (Ti 0.9 Hf 0.1 ) 0.99875 The O3-0.5 mol% BaCu(B2O5) mixture was weighed and prepared, and then subjected to a second ball milling. The weight ratio of powder, alcohol, and zirconium balls was 1:1.5:6. The mixture was ball-milled for 12 hours, then dried, ground, and passed through a 120-mesh sieve to obtain powder C. (4) Pour the powder C obtained in step (3) into a ball mill jar, add zirconium balls, alcohol, toluene, tributyl phosphate, o-xylene, PVB and defoamer in a certain proportion, and then ball mill for 12 h. After taking it out, sieve it to obtain slurry. (5) Pour the slurry obtained in step (4) into the material receiving tank of the coating machine, and then start the push rod to coat the slurry evenly to form a ceramic film on the PET film. The coating speed is 15 mm / s and the doctor blade height is 20 μm. After coating, place it in the air to dry. Then cut the ceramic film to the required size, stack it, and put it into a hot press for hot pressing. The pressure is 10 MPa, and it is kept at 80℃ for 1 h. After cutting, the green film is obtained. (6) Remove the binder from the green body obtained in step (5), heat it in an electric furnace at 550 ℃ for 5 h, then raise the temperature to 1000 ℃ and heat it for 0.5 h. Then sinter it in a sintering furnace at 1450 ℃ for 4 h, and then cool it naturally. The medium material is obtained. The dielectric material prepared in Example 9 was tested using a scanning electron microscope (SEM). Gold plating was required before testing. The results are as follows: Figure 1 As shown in -i, the magnification is 8100 times, the grain boundaries are relatively clear, the density is good, and the average grain size is 6.38 μm. The dielectric properties of the dielectric material prepared in Example 9 were tested, and it needed to be coated with a silver electrode before testing. The results are as follows: Figure 2 As shown in -i, the dielectric constant is 182 and the dielectric loss is 0.001 at room temperature. As the temperature increases, the dielectric constant decreases slightly and the dielectric loss increases. The dielectric material prepared in Example 9 was subjected to ferroelectric property testing. Prior to the test, it required polishing and thinning, and gold-plated electrodes. The results are as follows: Figure 3 As shown, this is a thin hysteresis loop with a breakdown field strength of 101.90 kV / mm and a maximum polarization of 23.83 μC / cm. 2 The remanent polarization intensity is 1.32 μC / cm. 2 The effective energy storage density was calculated to be 10.22 J / cm³ using the energy storage formula. 3 The total energy storage density is 11.37 J / cm³. 3 The energy storage efficiency is 89.9%. Example 10 (1) Using CaTiO3, TiO2, HfO2, and Dy2O3 as raw materials, according to the chemical composition expression Ca 0.995 Dy 0.005 (Ti 0.9 Hf 0.1 ) 0.99875 The O3 materials were weighed and poured into a ball mill jar, with the weight ratio of powder, alcohol, and zirconium balls being 1:1.5:6. The mixture was ball-milled for 12 hours, then dried in an oven at 85°C for 4 hours, followed by grinding and sieving through a 120-mesh sieve. The powder was then poured into a crucible, compacted, and pre-calcined in a sintering furnace at 1200°C for 4 hours. Finally, it was ground and sieved through a 120-mesh sieve to obtain the final powder. (2) Using BaCO3, CuO, and B2O3 as raw materials, the materials were weighed and prepared according to the chemical composition formula BaCu(B2O5). After weighing, the materials were poured into a ball mill jar, where the weight ratio of the medium powder, alcohol, and zirconium balls was 1:1.5:6. The materials were ball-milled for 8 hours, then dried, ground, and passed through a 120-mesh sieve. The powder was then poured into a crucible and calcined in a sintering furnace at 700 °C for 3 hours. After grinding, the powder was passed through a 120-mesh sieve to obtain powder B. (3) Powder A and powder B obtained in steps (1) and (2) are combined according to the chemical composition expression Ca 0.995 Dy 0.005 (Ti 0.9 Hf 0.1 ) 0.99875 The O3-1 mol% BaCu(B2O5) mixture was weighed and prepared, and then subjected to a second ball milling, wherein the weight ratio of powder, alcohol, and zirconium balls was 1:1.5:6. The mixture was ball-milled for 12 hours, then dried, ground, and passed through a 120-mesh sieve to obtain powder C. (4) Pour the powder C obtained in step (3) into a ball mill jar, add zirconium balls, alcohol, toluene, tributyl phosphate, o-xylene, PVB and defoamer in a certain proportion, and then ball mill for 12 h. After taking it out, sieve it to obtain slurry. (5) Pour the slurry obtained in step (4) into the material receiving tank of the coating machine, and then start the push rod to coat the slurry evenly to form a ceramic film on the PET film. The coating speed is 15 mm / s and the doctor blade height is 20 μm. After coating, place it in the air to dry. Then cut the ceramic film to the required size, stack it, and put it into a hot press for hot pressing. The pressure is 10 MPa, and it is kept at 80℃ for 1 h. After cutting, the green film is obtained. (6) Remove the binder from the green body obtained in step (5), heat it in an electric furnace at 550 ℃ for 5 h, then raise the temperature to 1000 ℃ and heat it for 0.5 h. Then sinter it in a sintering furnace at 1450 ℃ for 4 h, and then cool it naturally. The medium material is obtained. The dielectric material prepared in Example 10 was tested using a scanning electron microscope (SEM). Gold plating was required before testing. The results are as follows: Figure 1 As shown in -j, the magnification is 8100x, the grain boundaries are relatively clear, the density is good, and the average grain size is 6.39 μm. The dielectric material prepared in Example 10 was subjected to dielectric property testing, which required silver electrodes before testing. The results are as follows: Figure 2 As shown in Figure -j, the dielectric constant is 136 and the dielectric loss is 0.02 at room temperature. As the temperature increases, the dielectric constant decreases slightly and the dielectric loss increases. The dielectric material prepared in Example 10 was subjected to ferroelectric performance testing. Prior to the test, it required polishing and thinning, and gold-plated electrodes. The results are as follows: Figure 3 As shown, this is a thin hysteresis loop with a breakdown field strength of 74.93 kV / mm and a maximum polarization of 20.96 μC / cm. 2 The remanent polarization intensity is 0.67 μC / cm. 2 The effective energy storage density, calculated using the energy storage formula, is 6.92 J / cm³. 3 The total energy storage density is 7.38 J / cm³. 3The energy storage efficiency is 93.7%. Example 11 (1) Using CaTiO3, TiO2, HfO2, and Dy2O3 as raw materials, according to the chemical composition expression Ca 0.995 Dy 0.005 (Ti 0.9 Hf 0.1 ) 0.99875 The O3 materials were weighed and poured into a ball mill jar, with the weight ratio of powder, alcohol, and zirconium balls being 1:1.5:6. The mixture was ball-milled for 12 hours, then dried in an oven at 85°C for 4 hours, followed by grinding and sieving through a 120-mesh sieve. The powder was then poured into a crucible, compacted, and pre-calcined in a sintering furnace at 1200°C for 4 hours. Finally, it was ground and sieved through a 120-mesh sieve to obtain the final powder. (2) Using BaCO3, CuO, and B2O3 as raw materials, the materials were weighed and prepared according to the chemical composition formula BaCu(B2O5). After weighing, the materials were poured into a ball mill jar, where the weight ratio of the medium powder, alcohol, and zirconium balls was 1:1.5:6. The materials were ball-milled for 8 hours, then dried, ground, and passed through a 120-mesh sieve. The powder was then poured into a crucible and calcined in a sintering furnace at 700 °C for 3 hours. After grinding, the powder was passed through a 120-mesh sieve to obtain powder B. (3) Powder A and powder B obtained in steps (1) and (2) are combined according to the chemical composition expression Ca 0.995 Dy 0.005 (Ti 0.9 Hf 0.1 ) 0.99875 The O3-2 mol% BaCu(B2O5) mixture was weighed and prepared, and then subjected to a second ball milling, wherein the weight ratio of powder, alcohol, and zirconium balls was 1:1.5:6. The mixture was ball-milled for 12 hours, then dried, ground, and passed through a 120-mesh sieve to obtain powder C. (4) Pour the powder C obtained in step (3) into a ball mill jar, add zirconium balls, alcohol, toluene, tributyl phosphate, o-xylene, PVB and defoamer in a certain proportion, and then ball mill for 12 h. After taking it out, sieve it to obtain slurry. (5) Pour the slurry obtained in step (4) into the material receiving tank of the coating machine, and then start the push rod to coat the slurry evenly to form a ceramic film on the PET film. The coating speed is 15 mm / s and the doctor blade height is 20 μm. After coating, place it in the air to dry. Then cut the ceramic film to the required size, stack it, and put it into a hot press for hot pressing. The pressure is 10 MPa, and it is kept at 80℃ for 1 h. After cutting, the green film is obtained. (6) Remove the binder from the green body obtained in step (5), heat it in an electric furnace at 550 ℃ for 5 h, then raise the temperature to 1000 ℃ and heat it for 0.5 h. Then sinter it in a sintering furnace at 1400 ℃ for 4 h, and then cool it naturally. The medium material is obtained. The dielectric material prepared in Example 11 was tested using a scanning electron microscope (SEM). Gold plating was required before testing. The results are as follows: Figure 1 As shown in -k, the magnification is 8100 times, the grain boundaries are relatively clear, the density is good, and the average grain size is 10.25 μm. The dielectric properties of the dielectric material prepared in Example 11 were tested, and it needed to be subjected to a silver electrode before testing. The results are as follows: Figure 2 As shown in -k, the dielectric constant is 142 and the dielectric loss is 0.005 at room temperature. As the temperature increases, the dielectric constant decreases slightly and the dielectric loss increases. The dielectric material prepared in Example 11 was subjected to ferroelectric performance testing. Prior to the test, it required polishing and thinning, and gold-plated electrodes. The results are as follows: Figure 3 As shown, this is a thin hysteresis loop with a breakdown field strength of 64.94 kV / mm and a maximum polarization of 18.92 μC / cm. 2 The remanent polarization intensity is 0.39 μC / cm. 2 The effective energy storage density, calculated using the energy storage formula, is 5.54 J / cm³. 3 The total energy storage density is 5.80 J / cm³. 3 The energy storage efficiency is 95.5%. Table 1 shows the performance parameters of the energy storage medium ceramic materials prepared in each embodiment. Table 1 Dielectric ceramics Breakdown electric field strength (kV / mm) <![CDATA[Maximum polarization intensity (μC / cm 2 )]]> <![CDATA[Effective energy storage density (J / cm 3 )]]> <![CDATA[Total energy storage density (J / cm 3 )]]> Energy storage efficiency % Example 1 79.95 15.89 5.67 6.10 92.9 Example 2 49.96 9.74 2.25 2.45 91.7 Example 3 59.95 10.56 2.96 3.11 95.0 Example 4 39.96 7.11 1.34 1.44 93.5 Example 5 85.92 18.94 7.25 7.90 91.8 Example 6 67.93 16.72 4.36 5.64 77.3 Example 7 59.95 12.52 3.51 3.64 96.5 Example 8 89.92 22.41 6.89 10.06 68.5 Example 9 101.90 23.83 10.22 11.37 89.9 Example 10 74.93 20.96 6.92 7.38 93.7 Example 11 64.94 18.92 5.54 5.80 95.5 As shown in Table 1, the energy storage medium ceramic material prepared by this invention has good energy storage performance, with a breakdown field strength between 39.96 and 101.90 kV / mm and an effective energy storage density between 1.34 and 10.22 J / cm³. 3 Between these, most components have achieved significant performance improvements. In Ca... 0.995 Dy 0.005 (Ti 0.9 Hf 0.1 ) 0.99875 O3- The best energy storage performance was achieved in 0.5 mol% BaCu(B2O5) ceramics, with a breakdown field strength of 101.90 kV / mm and an effective energy storage density of 10.22 J / cm³. 3 . Figure 1SEM images of the energy storage medium ceramic materials prepared in Examples 1-11 are shown. All examples exhibit relatively clear grains and grain boundaries, and good density. With increasing Dy₂O₃ doping amount x, the average particle size generally decreases, attributed to the grain-refining effect of Dy ions. Conversely, with increasing MnO₂ or BaCu(B₂O₅), the porosity decreases, and the density increases. Figure 2 The graphs show the dielectric constant and loss of the energy storage ceramic materials prepared in Examples 1-11 as a function of temperature (25-400 °C) in the frequency range of 1 kHz to 1 MHz. The dielectric constant of most examples is around 150, and the loss is around 0.002 at room temperature. With increasing Dy₂O₃ doping amount x, the frequency dispersion phenomenon is enhanced, attributed to the increased local disorder caused by Dy ion doping and the accumulation of space charge at grain boundaries, thus enhancing the polarization type with slower response time. With increasing MnO₂ or BaCu(B₂O₅), the dielectric constant decreases slightly, but the dispersion phenomenon is less pronounced. Figure 3 The hysteresis loops of the energy storage dielectric ceramic materials prepared in Examples 1-11 are shown at 10 Hz. Most examples exhibit thin hysteresis loops, while a few MnO2-doped examples, such as Examples 6 and 8, have thicker hysteresis loops with lower energy storage efficiency. This may be attributed to the increased hysteresis loss due to defects such as multivalent Mn ions and oxygen vacancies. With the increase of Dy2O3 doping amount x, the breakdown field strength and energy storage density generally show a decreasing trend. This is attributed to the excessive grain boundary defects and increased porosity resulting from excessive Dy ion doping, leading to a decrease in breakdown field strength. However, with the appropriate increase of MnO2 or BaCu(B2O5), although the dielectric constant decreases slightly, the dielectric strength increases significantly. This is attributed to factors such as higher impedance, higher density, and larger band gap, ultimately resulting in higher dielectric strength in Ca... 0.995 Dy 0.005 (Ti 0.9 Hf 0.1 ) 0.99875 The best energy storage performance was obtained in O3-0.5 mol%BaCu(B2O5) ceramics. In summary, this invention provides a high-energy-storage calcium titanate-based dielectric material and its preparation method. Based on calcium titanate-based ceramics with high breakdown field strength, a series of strategies, including element substitution, doping with sintering aids, and process improvement, are employed to enhance energy storage performance. Partial substitution of Hf elements at the B site increases the band gap, and sintering aids improve grain density, both of which enhance the breakdown field strength. The addition of rare earth element Dy enhances the polarization response by introducing defect dipoles. Non-stoichiometric design reduces oxygen vacancy compensation and improves resistivity. The addition of a casting method improves density and uniformity. The dielectric ceramic material obtained by this invention exhibits excellent energy storage performance, especially in the case of Ca... 0.995 Dy 0.005 (Ti 0.9Hf 0.1 ) 0.99875 The best energy storage performance was achieved in O3-0.5 mol% BaCu(B2O5) ceramics, with a breakdown field strength of 101.90 kV / mm and an effective energy storage density of 10.22 J / cm³. 3 . The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A high-energy-storage calcium titanate-based dielectric material, characterized in that... The chemical composition formula is Ca 1-x Dy x (Ti 1-y Hf y ) 1-x / 4O3-z mol%M, where x=0.005~0.05, y=0.1~0.2, z=0~2, and M is MnO2 or BaCu(B2O5).

2. The high-energy-storage calcium titanate-based dielectric material according to claim 1, characterized in that... Where Ca 0.995 Dy 0.005 (Ti 0.9 Hf 0.1 ) 0.99875 O3-0.5 mol% BaCu(B2O5) ceramics exhibited the best energy storage performance, with a breakdown field strength of 101.90 kV / mm and a breakdown voltage of 10.22 J / cm². 3 Effective energy storage density.

3. A method for preparing a high-energy-storage calcium titanate-based dielectric material, comprising the following steps: (1) Using CaTiO3, TiO2, HfO2, and Dy2O3 as raw materials, according to the chemical composition expression Ca 1-x Dy x (Ti 1-y Hf y ) 1-x / 4 O3 was weighed and proportioned, with x = 0.005–0.05 and y = 0.1–0.

2. After weighing, the powder was poured into a ball mill jar, with a weight ratio of powder, alcohol, and zirconium balls of 1:1.5:

6. The mixture was ball-milled for 12 hours, then dried in an oven at 85 °C for 4 hours, followed by grinding and sieving through a 120-mesh sieve. The powder was then compacted in a crucible, pre-calcined in a sintering furnace at 1200 °C for 4 hours, and finally ground and sieved through a 120-mesh sieve to obtain powder A. (2) Using BaCO3, CuO, and B2O3 as raw materials, the materials were weighed and prepared according to the chemical composition formula BaCu(B2O5). After weighing, the materials were poured into a ball mill jar, with the weight ratio of powder, alcohol, and zirconium balls being 1:1.5:

6. The materials were ball-milled for 8 hours, then dried, ground, and passed through a 120-mesh sieve. The powder was then poured into a crucible and calcined in a sintering furnace at 700 °C for 3 hours. After grinding, the powder was passed through a 120-mesh sieve to obtain powder B. (3) Powder A and powder B obtained in steps (1) and (2) are combined according to the chemical composition expression Ca 1-x Dy x (Ti 1- y Hf y ) 1-x / 4 The O3-z mol%M was weighed and mixed, where x = 0.005~0.05, y = 0.1~0.2, z = 0~2, and M is MnO2 or BaCu(B2O5). Then, a second ball milling was performed, with the weight ratio of powder, alcohol, and zirconium balls being 1:1.5:

6. The mixture was ball-milled for 12 hours, then dried, ground, and passed through a 120-sieve to obtain powder C. (4) Pour the powder C obtained in step (3) into a ball mill jar, add zirconium balls, alcohol, toluene, tributyl phosphate, o-xylene, PVB and defoamer in a certain proportion, and then ball mill for 12 h. After taking it out, sieve it to obtain slurry. (5) Pour the slurry obtained in step (4) into the material receiving tank of the coating machine, and then start the push rod to coat the slurry evenly to form a ceramic film on the PET film. The coating speed is 15 mm / s and the doctor blade height is 20 μm. After coating, place it in the air to dry. Then cut the ceramic film to the required size, stack it, and put it into a hot press for hot pressing. The pressure is 10 MPa, and it is kept at 80 ℃ for 1 h. After cutting, the green film is obtained. (6) Remove the binder from the green body obtained in step (5), heat it in an electric furnace at 550 ℃ for 5 h, then raise the temperature to 1000 ℃ and heat it for 0.5 h. Then sinter it in a sintering furnace at 1400~1450 ℃ for 4 h, and then cool it naturally. The medium material is obtained.

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