A high energy storage density antiferroelectric ceramic material and its preparation method

Abstract

The present invention discloses a high energy storage density antiferroelectric ceramic material and a preparation method thereof. The chemical general formula is (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - x wt% Al2O3, where 0

Description

Technical Field

[0001] The present invention relates to the technical field of functional materials, and particularly relates to a high energy storage density antiferroelectric ceramic material and a preparation method thereof. Background Art

[0002] Dielectric capacitors have advantages such as high power, good reliability of density, and ultra-fast charge and discharge rates, and are widely used in modern scientific and technological fields such as electronic communication, automobiles, military, and aerospace. However, the existing energy storage dielectric materials currently have problems such as small energy storage density, low energy storage efficiency, and small discharge current, and cannot meet the development needs of current electronic devices. Antiferroelectric materials have almost zero remanent polarization intensity and extremely large polarization intensity, and their energy storage performance is superior to other dielectric materials. However, due to their low breakdown strength, the energy storage density is low, which greatly limits their application in the field of energy storage dielectrics. Therefore, studying dielectric materials with high breakdown strength and high energy storage density is the key to expanding their use fields.

[0003] Adding a high-insulating material reinforcing phase with characteristics such as low dielectric constant, low dielectric loss, wide bandgap width, and high breakdown strength to the ceramic matrix, the obtained composite material can simultaneously obtain the characteristics of the matrix and the reinforcing phase, and even obtain advantages that neither of them has. Combining the high-insulating material reinforcing phase with the ceramic matrix phase can improve the dielectric breakdown strength without significantly changing the electrical properties of the matrix ceramic, and finally obtain a composite ceramic dielectric material with better performance. Most of the high-insulating material reinforcing phases added to the ceramic matrix in the prior art are granular. Due to the shape and orientation arrangement problems of the reinforcing phase, the effect of enhancing the breakdown strength is not obvious, resulting in its energy storage density being difficult to meet the application requirements. Therefore, studying the shape and orientation of the added high-insulating material reinforcing phase in the ceramic matrix to effectively improve the breakdown strength of the antiferroelectric ceramic material and inducing a higher polarization intensity through a high electric field, thereby effectively improving the energy storage density of the antiferroelectric ceramic material has important significance. Summary of the Invention

[0004] The purpose of the present invention is to provide a high energy storage density antiferroelectric ceramic material and a preparation method thereof. The high-insulating material reinforcing phase Al2O3 flake template added to the antiferroelectric ceramic material is oriented in the same direction in the ceramic matrix and parallel to the test electrode, and has extremely high breakdown strength and energy storage density.

[0005] In order to achieve the above purpose, the technical solution of the present invention is:

[0006] A high energy storage density antiferroelectric ceramic material, the chemical general formula is (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 )0.995 O3 - x wt% Al2O3, where 0 < x ≤ 0.7, preferably, 0.1 ≤ x ≤ 0.7. Al2O3 is a flaky template, and the Al2O3 flaky templates are oriented in the same direction in the antiferroelectric ceramic material through a tape casting preparation process, and the Al2O3 flaky templates are regulated to be parallel to the test electrodes by polishing and sputtering gold on the upper and lower surfaces parallel to the Al2O3 flaky templates.

[0007] A preparation method of a high energy storage density antiferroelectric ceramic material, comprising the following steps:

[0008] S1: According to the chemical stoichiometric ratio of (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - x wt% Al2O3, prepare the powder raw materials of PbO, La2O3, ZrO2, and SnO2 in proportion. Put the powder raw materials, anhydrous ethanol solvent, and yttria-stabilized zirconia bead milling medium into a ball milling tank for ball milling, then dry and screen to obtain a mixed powder. Calcinate the mixed powder in a high-temperature furnace to synthesize (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 solid solution powder, that is, obtain PLZS solid solution powder;

[0009] S2: Add anhydrous ethanol solvent and yttria-stabilized zirconia bead milling medium to the PLZS solid solution powder obtained in step S1, then ball mill, dry, and screen to obtain PLZS fine powder;

[0010] S3: Add anhydrous ethanol solvent, butanone solvent, triethyl phosphate dispersant, polyvinyl butyral binder, dibutyl phthalate plasticizer, and yttria-stabilized zirconia bead milling medium to the PLZS fine powder obtained in step S2, and then ball mill to obtain a ceramic slurry;

[0011] S4: According to the chemical stoichiometric ratio of (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - x wt% Al2O3, proportionally add the Al2O3 flaky template, and then stir in a magnetic stirrer to obtain a mixed slurry;

[0012] S5: Use a vacuum degassing machine to degas the mixed slurry obtained in step S4 by stirring and vacuum pumping;

[0013] S6: Cast the mixed slurry obtained in step S5 by a manual casting machine. Through casting, the Al2O3 flake templates are oriented in the same direction in the matrix of the high energy storage density antiferroelectric ceramic material, and then dried and cut to obtain ceramic membrane sheets;

[0014] S7: Stack the ceramic membrane sheets obtained in step S6 according to the orientation of the Al2O3 flake templates in the matrix of the high energy storage density antiferroelectric ceramic material, place them in a mold, heat the mold through a heating jacket, hot press with a manual tablet press and compact with a cold isostatic press, and then manually cut to obtain a green ceramic body;

[0015] S8: Place the green ceramic body obtained in step S7 in a muffle furnace for debinding and sintering to obtain a sintered ceramic sheet;

[0016] S9: Polish, ultrasonically clean and dry the upper and lower surfaces of the sintered ceramic sheet obtained in step S8 that are parallel to the Al2O3 flake templates, and spray gold on the upper and lower surfaces parallel to the Al2O3 flake templates to obtain a finished high energy storage density antiferroelectric ceramic material with the Al2O3 flake templates and test electrodes arranged in parallel.

[0017] Preferably, in step S7, stack the ceramic membrane sheets obtained in step S6 according to the orientation of the Al2O3 flake templates in the same direction, place them in a mold, heat the mold through a heating jacket, hot press with a manual tablet press and compact with a cold isostatic press, and then manually cut to obtain a green ceramic body.

[0018] Preferably, in step S4, place the ceramic slurry obtained in step S3 in a beaker, add a magnetic stirrer in the beaker, and then according to the chemical stoichiometric ratio of the chemical formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - xwt% Al2O3, equip and add Al2O3 flake templates in proportion. The mass of the added Al2O3 flake templates is xwt% of the mass of the PLZS fine powder in step S2, and then place the beaker on a magnetic stirrer and stir. The stirring speed is 450 - 600 r / min, and the stirring time is 24 - 36 h. After stirring, a mixed slurry is obtained.

[0019] Preferably, in step S1, the mass ratio of the anhydrous ethanol solvent to the powder raw material is (0.8 - 0.9):1, the mass ratio of the yttrium-stabilized zirconia beads to the powder raw material is (4.5 - 3.5):1, the ball milling speed is 280 - 300 r / min, the ball milling time is 12 - 24 h, and then it is dried and sieved to obtain a mixed powder. The mixed powder is calcined in a muffle furnace at 800 °C for 2 h to synthesize a PLZS solid solution powder.

[0020] Preferably, in step S2, the mass ratio of the absolute ethanol solvent to the PLZS solid solution powder is (0.8 - 0.9):1, the mass ratio of the yttrium-stabilized zirconia bead milling medium to the PLZS solid solution powder is (4.5 - 3.5):1, the milling speed is 280 - 300 r / min, the milling time is 24 - 36 h, and then after drying and screening, PLZS fine powder is obtained.

[0021] Preferably, in step S3, the mass ratio of the absolute ethanol solvent to the PLZS fine powder is (4 - 5):10, the mass ratio of the methyl ethyl ketone solvent to the PLZS fine powder is (3 - 4):10, the mass ratio of the triethyl phosphate dispersant to the PLZS fine powder is (0.2 - 0.4):10, the mass ratio of the polyvinyl butyral binder to the PLZS fine powder is (0.6 - 0.7):10, the mass ratio of the dibutyl phthalate plasticizer to the PLZS fine powder is (0.6 - 0.7):10, the mass ratio of the yttrium-stabilized zirconia beads to the PLZS fine powder is (4.5 - 3.5):1, the milling speed is 280 - 300 r / min, and the milling time is 24 - 36 h.

[0022] Preferably, in step S4, the mass of the added Al2O3 flake template is (0.1 - 0.7)% of the mass of the PLZS fine powder in step S2, the stirring speed of the magnetic stirrer is 450 - 600 r / min, and the stirring time of the magnetic stirrer is 24 - 36 h.

[0023] Preferably, in step S5, the defoaming time of the vacuum defoamer is 1 - 2 h, and the stirring speed is 150 - 350 r / min.

[0024] In the above technical solution, a high energy storage density antiferroelectric ceramic material and its preparation method of the present invention have the following beneficial technical effects:

[0025] (1) The Al2O3 flake template is first prepared by the molten salt method and then tape-cast (also called doctor blading) by the tape-casting process. This tape-casting process can make the Al2O3 flake template orient in the same direction in the antiferroelectric ceramic material matrix. Then, by polishing and sputtering gold on the upper and lower surfaces parallel to the Al2O3 flake template, an antiferroelectric ceramic material with the Al2O3 flake template and the test electrodes arranged in parallel is obtained, enabling the Al2O3 flake template to effectively disperse the applied electric field in the entire antiferroelectric ceramic material matrix, reducing the non-uniform distribution of the local electric field, being beneficial to improving the breakdown strength of the antiferroelectric ceramic material, and thus increasing the energy storage density of the antiferroelectric ceramic material.

[0026] Due to the small aspect ratio of the existing granular Al2O3 reinforcement phase, after applying an electric field, the local electric field will concentrate at both ends parallel to the electric field direction, increasing the probability of breakdown behavior. Through the tape casting preparation and forming process, the Al2O3 flake templates are oriented in the same direction in the matrix of the antiferroelectric ceramic material. Then, polishing and gold spraying are carried out on the upper and lower surfaces parallel to the Al2O3 flake templates to obtain an antiferroelectric ceramic material with the Al2O3 flake templates and the test electrodes arranged in parallel. The Al2O3 flake templates can effectively disperse the applied electric field in the entire matrix of the antiferroelectric ceramic material, reducing the non-uniform distribution of the local electric field, which is beneficial to improving the breakdown strength of the antiferroelectric ceramic material and thus increasing the energy storage density of the antiferroelectric ceramic material. Since the flake Al2O3 template belongs to a high-insulation material with the characteristic of high breakdown strength under high voltage, adding the Al2O3 flake template can increase the resistance of the composite material, thereby increasing the number of bound charges and reducing the movement of free charges. In addition, due to the large aspect ratio of the parallel-aligned Al2O3 flake templates, the applied electric field can be effectively dispersed in the entire matrix of the antiferroelectric ceramic material to reduce the non-uniform distribution of the local electric field. At the same time, when an electric field is applied, the parallel-aligned Al2O3 flake templates in the composite material can form a relatively wide interfacial potential barrier, which has an obstructive effect on charge carriers, thereby reducing the leakage current and effectively hindering the extension of the electrical tree path, reducing the growth rate of the electrical tree, or even stopping its growth, avoiding the breakdown behavior of the composite material. All of the above are beneficial to improving the breakdown strength of the antiferroelectric ceramic material and thus increasing the energy storage density of the antiferroelectric ceramic material.

[0027] (2) After the sufficient stirring step of the tape casting preparation process, adding the second-phase Al2O3 flake template is beneficial to improving the breakdown strength of the antiferroelectric ceramic material composite and thus increasing the energy storage density of the antiferroelectric ceramic material.

[0028] After the sufficient stirring step of the tape casting preparation process, the Al2O3 flake templates are uniformly distributed in the antiferroelectric ceramic material. The dielectric constant of Al2O3 is about 10, (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995The dielectric constant of the O3 solid solution powder ceramic is about 500, and the difference in dielectric constant between the two is relatively large. According to the voltage division theory, when an electric field is applied, due to the low dielectric constant of Al2O3, more voltage will accumulate on Al2O3, thus forming a local electric field distribution. The breakdown field strength of Al2O3 itself is relatively high and can withstand a higher electric field intensity, enabling the matrix of the antiferroelectric ceramic material in the composite material to withstand a higher voltage than that of pure ceramics. Therefore, adding the second-phase Al2O3 flake template is beneficial to improving the breakdown strength of the antiferroelectric ceramic material composite, and further improving the energy storage density of the antiferroelectric ceramic material.

[0029] (3) The Al2O3 flake template exists as the second phase in the antiferroelectric ceramic material composite and does not change the antiferroelectric properties of the antiferroelectric ceramic material composite, enabling the characteristics of the multi-stage phase transformation of the matrix ceramic of the antiferroelectric ceramic material to be maintained while obtaining a high breakdown strength. Under the induction of a high electric field, due to the antiferroelectric-ferroelectric phase transformation in the antiferroelectric system of the antiferroelectric ceramic material, the polarization intensity can be greatly enhanced. According to the formula, with the increase of the polarization intensity P, the value of the energy storage density W rec can be effectively guaranteed to increase.

[0030] (4) The composition and process of the present invention are simple, easy to operate, have good repeatability, and the raw materials are cheap and easily available. Description of the Drawings

[0031] Figure 1 It is the XRD pattern of the ceramic materials of Examples 1-4 and Comparative Example 1 of the present invention.

[0032] Figure 2 It is the SEM pattern of the cross-section of the ceramic materials of Examples 1-4 and Comparative Example 1 of the present invention

[0033] Figure 3 It is the EDS pattern of Example 1.

[0034] Figure 4 It is the pattern of the variation law of the relative dielectric constant of the ceramic materials of Examples 1-4 and Comparative Example 1 of the present invention with temperature.

[0035] Figure 5 It is the electric hysteresis loop of the ceramic materials of Examples 1-4 of the present invention.

[0036] Figure 6 It is the electric hysteresis loop of the ceramic materials of Comparative Examples 1-13. Detailed Embodiments

[0037] For the convenience of understanding, a high energy storage density antiferroelectric ceramic material and its preparation method will be described below in combination with embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention.

[0038] In this example, the reagents and raw materials used are all commercially available Sinopharm reagents unless otherwise specified.

[0039] A high energy storage density antiferroelectric ceramic material with the chemical general formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - x wt% Al2O3, where 0 < x ≤ 0.7, Al2O3 is a flaky Al2O3 template. The flaky Al2O3 template is oriented in the same direction in the antiferroelectric ceramic material through a tape casting preparation process and is adjusted to be parallel to the test electrode by polishing and gold spraying on the upper and lower surfaces parallel to the flaky Al2O3 template.

[0040] Preferably, the chemical general formula is (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - x wt% Al2O3, where 0.1 ≤ x ≤ 0.7, Al2O3 is a flaky Al2O3 template. The flaky Al2O3 template is oriented in the same direction in the antiferroelectric ceramic material through a tape casting preparation process and is adjusted to be parallel to the test electrode by polishing and gold spraying on the upper and lower surfaces parallel to the flaky Al2O3 template.

[0041] A preparation method of a high energy storage density antiferroelectric ceramic material, comprising the following steps:

[0042] S1: According to the stoichiometric ratio of the chemical general formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - x wt% Al2O3, prepare the powder raw materials of PbO, La2O3, ZrO2, and SnO2 in proportion. Put the powder raw materials, anhydrous ethanol solvent, and yttria - stabilized zirconia bead milling medium into a ball milling tank for ball milling. The mass ratio of the anhydrous ethanol solvent to the powder raw materials is (0.8 - 0.9):1, and the mass ratio of the yttria - stabilized zirconia beads to the powder raw materials is (4.5 - 3.5):1. The ball milling speed is 280 - 300 r / min, and the ball milling time is 12 - 24 h. Then dry and screen to obtain a mixed powder. Calcinate the mixed powder in a muffle furnace at 800 °C for 2 h to synthesize (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 solid solution powder, that is, obtain the PLZS solid solution powder;

[0043] S2: Add absolute ethanol solvent and yttria-stabilized zirconia bead milling media to the PLZS solid solution powder obtained in step S1, and then carry out ball milling. The mass ratio of the absolute ethanol solvent to the PLZS solid solution powder is (0.8 - 0.9):1, the mass ratio of the yttria-stabilized zirconia bead milling media to the PLZS solid solution powder is (4.5 - 3.5):1, the ball milling speed is 280 - 300 r / min, the ball milling time is 24 - 36 h, and then dry and screen to obtain PLZS fine powder.

[0044] S3: Add absolute ethanol solvent, methyl ethyl ketone solvent, triethyl phosphate dispersant, polyvinyl butyral binder, dibutyl phthalate plasticizer, and yttria-stabilized zirconia bead milling media to the PLZS fine powder obtained in step S2, and then carry out ball milling. The mass ratio of the absolute ethanol solvent to the PLZS fine powder is (4 - 5):10, the mass ratio of the methyl ethyl ketone solvent to the PLZS fine powder is (3 - 4):10, the mass ratio of the triethyl phosphate dispersant to the PLZS fine powder is (0.2 - 0.4):10, the mass ratio of the polyvinyl butyral binder to the PLZS fine powder is (0.6 - 0.7):10, the mass ratio of the dibutyl phthalate plasticizer to the PLZS fine powder is (0.6 - 0.7):10, the mass ratio of the yttria-stabilized zirconia beads to the PLZS fine powder is (4.5 - 3.5):1, the ball milling speed is 280 - 300 r / min, the ball milling time is 24 - 36 h, and ceramic slurry is obtained after ball milling;

[0045] S4: Place the ceramic slurry obtained in step S3 in a beaker, add a magnetic stirring bar to the beaker, and then according to the chemical formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - xwt%Al2O3 stoichiometric ratio, proportionally add Al2O3 flake templates prepared by the molten salt method according to patent CN107326432. The radial diameter of the Al2O3 flake template is 9.5 μm and the thickness is 0.55 μm. The mass of the added Al2O3 flake template is xwt% of the mass of the PLZS fine powder in step S2, and then place the beaker on a magnetic stirrer and stir. The stirring speed is 450 - 600 r / min and the stirring time is 24 - 36 h. After stirring, a mixed slurry is obtained, and the viscosity of the mixed slurry reaches about 1000 Pa·S;

[0046] S5: Use a vacuum degassing machine to degas the mixed slurry obtained in step S4 by stirring and vacuum pumping. The vacuum degassing time is 1 - 2 h and the stirring speed is 150 - 350 r / min;

[0047] S6: Cast the slurry obtained in step S5 using a manual casting machine. According to the literature "G.N. Howatt, R.G. Breckenridge, J.M.Brownlow. Fabrication of Thin Ceramic Sheets for Capacitors. Journal of the American Ceramic Society, 30[8] 237 - 42(1947)", through the casting preparation process, the Al2O3 flake templates are oriented in the same direction in the matrix of the high energy storage density antiferroelectric ceramic material. The casting speed of the manual casting machine is 3.5 - 4 cm / min, and the single layer thickness of the obtained ceramic film is 0.07 - 0.09 mm. After drying and cutting, a ceramic film with a size of 25 mm × 25 mm is obtained;

[0048] S7: Stack the ceramic films obtained in step S6 with the Al2O3 flake templates oriented in the same direction and place them in a mold. The ceramic film stack is 20 - 25 layers. Heat the mold using a heating jacket and perform hot pressing using a manual press. The hot pressing temperature of the manual press is 50 - 60 °C, the hot pressing pressure of the manual press is 20 - 25 Mpa, and the pressure holding time is 10 - 15 min. Then compact it using a cold isostatic press at a pressure of 200 - 300 MPa to obtain a large square ceramic green body with a size of 25 mm × 25 mm and a thickness of 1 - 1.5 mm. Finally, manually cut it to obtain a small square ceramic green body with a size of 5 mm × 5 mm and a thickness of 1 - 1.5 mm;

[0049] S8: Place the small square green body obtained in step S7 in an Al2O3 crucible, and then place the Al2O3 crucible in a muffle furnace for debinding. After sintering at 600 - 650 °C for 4 - 6 h, then sinter at 1170 - 1200 °C for 3 - 4 h to obtain a sintered ceramic sheet with a dense structure;

[0050] S9: Polish the upper and lower surfaces of the sintered ceramic sheet obtained in step S8 parallel to the Al2O3 flake templates to a thickness of 0.1 - 0.12 mm, then ultrasonically clean and dry it, and then spray gold on the upper and lower surfaces parallel to the Al2O3 flake templates to obtain a finished product of the high energy storage density antiferroelectric ceramic material with the Al2O3 flake templates and the test electrodes arranged in parallel.

[0051] The above steps S3 - S8 are the casting preparation process. The PLZS fine powder is ball - milled and mixed evenly with organic solvents such as anhydrous ethanol, butanone solvent, polyvinyl butyral binder, triethyl phosphate dispersant, and dibutyl phthalate plasticizer, so that the film obtained after casting the slurry has plasticity. The ball - milled slurry is poured out and placed in a beaker. A magnetic stirrer is added to the beaker, and then Al2O3 flake templates are added to the beaker. Then the beaker is placed on a magnetic stirrer for stirring. After stirring evenly, when the viscosity of the slurry reaches about 1000 Pa·S, the slurry is poured into the degassing tank of a vacuum degassing machine and then placed in the vacuum degassing machine. Defoaming is carried out by stirring and vacuum pumping, and then casting is carried out on a manual casting machine. After that, through processes such as lamination, hot - pressing heat treatment, etc., a composite ceramic with Al2O3 flake templates oriented in the same direction in the PLZS matrix ceramic can be obtained. The composite ceramic is then polished and sprayed with gold on the upper and lower surfaces parallel to the Al2O3 flake templates, and finally a ceramic product with the Al2O3 flake templates parallel to the test electrodes is obtained.

[0052] Example 1:

[0053] A high - energy - storage - density antiferroelectric ceramic material with the chemical general formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - 0.3 wt% Al2O3, abbreviated as PLZS - 0.3 wt% Al2O3. Among them, in the chemical general formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - x wt% Al2O3, x = 0.3, Al2O3 is the Al2O3 flake template. The Al2O3 flake templates are oriented in the same direction in the antiferroelectric ceramic material through the casting preparation process and the parallelism of the Al2O3 flake templates to the test electrodes is regulated by polishing and spraying gold on the upper and lower surfaces parallel to the Al2O3 flake templates.

[0054] A preparation method of a high - energy - storage - density antiferroelectric ceramic material, comprising the following steps:

[0055] S1: According to the chemical general formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995The stoichiometric ratio of O3 - 0.3wt% Al2O3 is used to prepare the powder raw materials of PbO, La2O3, ZrO2, and SnO2 in proportion. The powder raw materials, anhydrous ethanol solvent, and yttrium-stabilized zirconia bead milling medium are put into a ball mill jar for ball milling. The mass ratio of the anhydrous ethanol solvent to the powder raw materials is (0.8 - 0.9):1, the mass ratio of the yttrium-stabilized zirconia beads to the powder raw materials is (4.5 - 3.5):1, the ball milling speed is 280 - 300 r / min, and the ball milling time is 12 - 24 h. After drying and screening, a mixed powder is obtained. The mixed powder is calcined in a muffle furnace at 800 °C for 2 h to synthesize (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 solid solution powder, that is, PLZS solid solution powder is obtained;

[0056] S2: Add anhydrous ethanol solvent and yttrium-stabilized zirconia bead milling medium to the PLZS solid solution powder obtained in step S1 and then carry out ball milling. The mass ratio of the anhydrous ethanol solvent to the PLZS solid solution powder is (0.8 - 0.9):1, the mass ratio of the yttrium-stabilized zirconia bead milling medium to the PLZS solid solution powder is (4.5 - 3.5):1, the ball milling speed is 280 - 300 r / min, and the ball milling time is 24 - 36 h. After drying and screening, PLZS fine powder is obtained.

[0057] S3: Add anhydrous ethanol solvent, butanone solvent, triethyl phosphate dispersant, polyvinyl butyral binder, dibutyl phthalate plasticizer, and yttrium-stabilized zirconia bead milling medium to the PLZS fine powder obtained in step S2 and then carry out ball milling. The mass ratio of the anhydrous ethanol solvent to the PLZS fine powder is (4 - 5):10, the mass ratio of the butanone solvent to the PLZS fine powder is (3 - 4):10, the mass ratio of the triethyl phosphate dispersant to the PLZS fine powder is (0.2 - 0.4):10, the mass ratio of the polyvinyl butyral binder to the PLZS fine powder is (0.6 - 0.7):10, the mass ratio of the dibutyl phthalate plasticizer to the PLZS fine powder is (0.6 - 0.7):10, the mass ratio of the yttrium-stabilized zirconia beads to the PLZS fine powder is (4.5 - 3.5):1, the ball milling speed is 280 - 300 r / min, and the ball milling time is 24 - 36 h. After ball milling, a ceramic slurry is obtained;

[0058] S4: Place the ceramic slurry obtained in step S3 in a beaker, add a magnetic stirrer to the beaker, and then according to the chemical formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995The stoichiometric ratio of O3 - 0.3wt% Al2O3 is prepared proportionally, and the Al2O3 flake template obtained by the molten salt method according to Patent CN107326432 is added. The radial diameter of the Al2O3 flake template is 9.5 μm, and the thickness is 0.55 μm. The mass of the added Al2O3 flake template is 0.3% of the mass of the PLZS fine powder in step S2. Then, the beaker is placed on a magnetic stirrer and stirred at a stirring speed of 450 - 600 r / min for 24 - 36 h to obtain a mixed slurry, and the viscosity of the mixed slurry reaches about 1000 Pa·S;

[0059] S5: The mixed slurry obtained in step S4 is defoamed by a vacuum defoamer through stirring and vacuum pumping. The vacuum defoaming time is 1 - 2 h, and the stirring speed is 150 - 350 r / min;

[0060] S6: The slurry obtained in step S5 is cast by a manual casting machine. According to the literature "G.N. Howatt, R.G. Breckenridge, J.M. Brownlow. Fabrication of Thin Ceramic Sheets for Capacitors. Journal of the American Ceramic Society, 30[8] 237 - 42(1947)", through the casting preparation process, the Al2O3 flake templates are oriented in the same direction in the matrix of the high - energy - density antiferroelectric ceramic material. The casting speed of the manual casting machine is 3.5 - 4 cm / min, and the single - layer thickness of the obtained ceramic film is 0.07 - 0.09 mm. After drying and cutting, a ceramic film with a size of 25 mm × 25 mm is obtained;

[0061] S7: The ceramic films obtained in step S6 are stacked with the Al2O3 flake templates oriented in the same direction and placed in a mold. The ceramic film stack is 20 - 25 layers. The mold is heated by a heating jacket, and hot pressing is carried out by a manual press. The hot - pressing temperature of the manual press is 50 - 60 °C, the hot - pressing pressure of the manual press is 20 - 25 Mpa, and the pressure - holding time is 10 - 15 min. Then, it is compacted by a cold isostatic press at a pressure of 200 - 300 MPa to obtain a large - square ceramic green body with a size of 25 mm × 25 mm and a thickness of 1 - 1.5 mm. Finally, it is manually cut to obtain a small - square ceramic green body with a size of 5 mm × 5 mm and a thickness of 1 - 1.5 mm;

[0062] S8: The small - square green body obtained in step S7 is placed in an Al2O3 crucible, and then the Al2O3 crucible is placed in a muffle furnace for debinding. After sintering at 600 - 650 °C for 4 - 6 h, it is sintered at 1170 - 1200 °C for 3 - 4 h to obtain a sintered ceramic sheet with a dense structure;

[0063] S9: Polish the upper and lower surfaces of the sintered ceramic sheet obtained in step S8 that are parallel to the Al2O3 flake template to a thickness of 0.1 - 0.12 mm, then ultrasonically clean and dry it, and then sputter gold on the upper and lower surfaces parallel to the Al2O3 flake template to obtain a finished product of a high energy storage density antiferroelectric ceramic material with the Al2O3 flake template and the test electrode arranged in parallel.

[0064] Example 2:

[0065] A high energy storage density antiferroelectric ceramic material with the chemical general formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - 0.1 wt% Al2O3, abbreviated as PLZS - 0.1 wt% Al2O3. Among them, in the chemical general formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - x wt% Al2O3, x = 0.1, Al2O3 is the Al2O3 flake template, and the Al2O3 flake template is oriented in the same direction in the antiferroelectric ceramic material through the tape casting preparation process and the Al2O3 flake template is adjusted to be parallel to the test electrode by polishing and sputtering gold on the upper and lower surfaces parallel to the Al2O3 flake template.

[0066] A preparation method of a high energy storage density antiferroelectric ceramic material, comprising the following steps:

[0067] The difference from Example 1 is that in step S4, the mass of the added Al2O3 flake template is 0.1% of the mass of the PLZS fine powder in step S2.

[0068] Example 3:

[0069] A high energy storage density antiferroelectric ceramic material with the chemical general formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - 0.5 wt% Al2O3, abbreviated as PLZS - 0.5 wt% Al2O3. Among them, in the chemical general formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995In O3 - xwt% Al2O3, x = 0.5, and Al2O3 is a flaky Al2O3 template. The flaky Al2O3 template is oriented in the same direction in the antiferroelectric ceramic material through a tape casting preparation process, and the flaky Al2O3 template is adjusted to be parallel to the test electrode by polishing and spraying gold on the upper and lower surfaces parallel to the flaky Al2O3 template.

[0070] A preparation method of a high energy storage density antiferroelectric ceramic material, comprising the following steps:

[0071] The difference from Example 1 is that in step S4, the mass of the added flaky Al2O3 template is 0.5% of the mass of the PLZS fine powder in step S2.

[0072] Example 4:

[0073] A high energy storage density antiferroelectric ceramic material with the chemical general formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - 0.7wt% Al2O3, abbreviated as PLZS - 0.7wt% Al2O3. Among them, in the chemical general formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - xwt% Al2O3, x = 0.7, and Al2O3 is a flaky Al2O3 template. The flaky Al2O3 template is oriented in the same direction in the antiferroelectric ceramic material through a tape casting preparation process, and the flaky Al2O3 template is adjusted to be parallel to the test electrode by polishing and spraying gold on the upper and lower surfaces parallel to the flaky Al2O3 template.

[0074] A preparation method of a high energy storage density antiferroelectric ceramic material, comprising the following steps:

[0075] The difference from Example 1 is that in step S4, the mass of the added flaky Al2O3 template is 0.7% of the mass of the PLZS fine powder in step S2.

[0076] Comparative Example 1:

[0077] A high energy storage density antiferroelectric ceramic material with the chemical general formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3, abbreviated as PLZS.

[0078] A preparation method of a high energy storage density antiferroelectric ceramic material, comprising the following steps:

[0079] The difference from Example 1 is that after step S3, instead of performing step S4, step S5 is directly carried out.

[0080] Comparative Example 2:

[0081] A high energy storage density antiferroelectric ceramic material with a chemical general formula of (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - 0.3wt% Al2O3, abbreviated as PLZS - 0.3wt% Al2O3. Among them, in the chemical general formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - xwt% Al2O3, x = 0.3, Al2O3 is in granular form, and the granular Al2O3 is randomly arranged in the antiferroelectric ceramic material.

[0082] A preparation method of a high energy storage density antiferroelectric ceramic material, comprising the following steps:

[0083] The difference from Example 1 is that in step S4, the ceramic slurry obtained in step S3 is placed in a beaker, and then a magnetic stirrer is added to the beaker. Then, according to the stoichiometric ratio of the chemical general formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - 0.3wt% Al2O3, granular Al2O3 is proportionally added. The mass of the added granular Al2O3 is 0.3% of the mass of the PLZS fine powder in step S2.

[0084] Comparative Example 3:

[0085] A high energy storage density antiferroelectric ceramic material with a chemical general formula of (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - 0.1wt% Al2O3, abbreviated as PLZS - 0.1wt% Al2O3. Among them, in the chemical general formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - xwt% Al2O3, x = 0.1, Al2O3 is in granular form, and the granular Al2O3 is randomly arranged in the antiferroelectric ceramic material.

[0086] A preparation method of a high energy storage density antiferroelectric ceramic material, comprising the following steps:

[0087] The difference from Example 2 is that in step S4, the ceramic slurry obtained in step S3 is placed in a beaker, and a magnetic stirrer is added to the beaker. Then, according to the chemical stoichiometric ratio of (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - 0.1wt% Al2O3, granular Al2O3 is proportionally added, and the mass of the added granular Al2O3 is 0.1% of the mass of the PLZS fine powder in step S2.

[0088] Comparative Example 4:

[0089] A high energy storage density antiferroelectric ceramic material with the chemical formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - 0.5wt% Al2O3, abbreviated as PLZS - 0.5wt% Al2O3, wherein in the chemical formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - xwt% Al2O3, x = 0.5, Al2O3 is granular, and the granular Al2O3 is randomly arranged in the antiferroelectric ceramic material.

[0090] A preparation method of a high energy storage density antiferroelectric ceramic material, comprising the following steps:

[0091] The difference from Example 3 is that in step S4, the ceramic slurry obtained in step S3 is placed in a beaker, and a magnetic stirrer is added to the beaker. Then, according to the chemical stoichiometric ratio of (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - 0.5wt% Al2O3, granular Al2O3 is proportionally added, and the mass of the added granular Al2O3 is 0.5% of the mass of the PLZS fine powder in step S2.

[0092] Comparative Example 5:

[0093] A high energy storage density antiferroelectric ceramic material with the chemical formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 )0.995 O3 - 0.7 wt% Al2O3, abbreviated as PLZS - 0.7 wt% Al2O3, where the chemical general formula is (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - x wt% Al2O3, x = 0.7, Al2O3 is in granular form, and the granular Al2O3 is randomly arranged in the antiferroelectric ceramic material.

[0094] A preparation method of a high - energy - storage - density antiferroelectric ceramic material, comprising the following steps:

[0095] The difference from Example 4 is that in step S4, the ceramic slurry obtained in step S3 is placed in a beaker, and then a magnetic stirrer is added to the beaker. Then, according to the stoichiometric ratio of (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - 0.7 wt% Al2O3, granular Al2O3 is added proportionally. The mass of the added granular Al2O3 is 0.7% of the mass of the PLZS fine powder in step S2.

[0096] Comparative Example 6:

[0097] A high - energy - storage - density antiferroelectric ceramic material with the chemical general formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - 0.3 wt% Al2O3, abbreviated as PLZS - 0.3 wt% Al2O3, where the chemical general formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - x wt% Al2O3, x = 0.3, Al2O3 is in the form of flaky templates, and the Al2O3 flaky templates are randomly arranged in the antiferroelectric ceramic material through a solid - phase preparation process.

[0098] A preparation method of a high - energy - storage - density antiferroelectric ceramic material, comprising the following steps:

[0099] The difference from Example 1 is that in Example 1, the tape - casting preparation process is used in steps S3 - S8, while in Comparative Example 6, the solid - phase preparation process is used starting from step S3. The differences starting from step S3 compared with Example 1 are as follows:

[0100] S3: Put the PLZS fine powder, Al2O3 flaky template, absolute ethanol solvent and magnetic stirrer obtained in step S2 into a beaker, add 0.3% of the mass of the Al2O3 flaky template in step S2 based on the mass of the PLZS fine powder, and then stir in a magnetic stirrer at a stirring speed of 450 - 600 r / min for 24 - 36 h to obtain a mixed slurry;

[0101] S4: Dry the mixed slurry obtained in step S3 in an oven to obtain a mixed powder;

[0102] S5: Press the mixed powder obtained in step S4 into a circular ceramic green body with a diameter of 6 mm and a thickness of 1 - 1.5 mm under a pressure of 200 - 300 MPa by cold isostatic pressing;

[0103] S6: Place the ceramic green body obtained in step S5 in an Al2O3 crucible, then put the Al2O3 crucible into a muffle furnace and sinter at 1170 - 1200 °C for 3 - 4 h to obtain a sintered ceramic sheet with a dense structure;

[0104] S7: Polish the sintered ceramic sheet obtained in step S6 to a thickness of 0.1 - 0.12 mm, then ultrasonically clean and dry it, and spray gold on its upper and lower surfaces to obtain a finished product of a high energy storage density antiferroelectric ceramic material.

[0105] Comparative Example 7:

[0106] An antiferroelectric ceramic material with high energy storage density, the chemical general formula is (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - 0.1 wt% Al2O3, abbreviated as PLZS - 0.1 wt% Al2O3, wherein in the chemical general formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - x wt% Al2O3, x = 0.1, Al2O3 is a flaky template, and the Al2O3 flaky template is randomly arranged in the antiferroelectric ceramic material through a solid-phase preparation process.

[0107] A preparation method of an antiferroelectric ceramic material with high energy storage density, comprising the following steps:

[0108] The difference from Example 2 is that: in Example 2, the tape casting preparation process is used in steps S3 - S8, and in Comparative Example 7, the solid-phase preparation process is used starting from step S3. The difference starting from step S3 from Comparative Example 6 is as follows:

[0109] S3: Add the mass of the Al2O3 flake template to be 0.1% of the mass of the PLZS fine powder in step S2.

[0110] Comparative Example 8:

[0111] A high energy storage density antiferroelectric ceramic material with the chemical general formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - 0.5wt% Al2O3, abbreviated as PLZS - 0.5wt% Al2O3. Among them, in the chemical general formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - xwt% Al2O3, x = 0.5, Al2O3 is a flake template, and the Al2O3 flake template is randomly arranged in the antiferroelectric ceramic material through a solid-phase preparation process.

[0112] A preparation method of a high energy storage density antiferroelectric ceramic material, comprising the following steps:

[0113] The difference from Example 3 is that in Example 3, the tape casting preparation process is used in steps S3 - S8, and in Comparative Example 8, the solid-phase preparation process is used starting from step S3. The difference between starting from step S3 and Comparative Example 6 is as follows:

[0114] S3: Add the mass of the Al2O3 flake template to be 0.5% of the mass of the PLZS fine powder in step S2.

[0115] Comparative Example 9:

[0116] A high energy storage density antiferroelectric ceramic material with the chemical general formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - 0.7wt% Al2O3, abbreviated as PLZS - 0.7wt% Al2O3. Among them, in the chemical general formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - xwt% Al2O3, x = 0.7, Al2O3 is a flake template, and the Al2O3 flake template is randomly arranged in the antiferroelectric ceramic material through a solid-phase preparation process.

[0117] A preparation method of a high energy storage density antiferroelectric ceramic material, comprising the following steps:

[0118] The difference from Example 4 is that in Example 4, the tape casting preparation process is adopted in steps S3 - S8, while in Comparative Example 9, the solid - phase method preparation process is adopted starting from step S3. The differences starting from step S3 compared with Comparative Example 6 are as follows:

[0119] S3: The mass of the Al2O3 flake template added is 0.7% of the mass of the PLZS fine powder in step S2.

[0120] Comparative Example 10:

[0121] A high - energy - storage - density antiferroelectric ceramic material with the chemical general formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - 0.3wt% Al2O3, abbreviated as PLZS - 0.3wt% Al2O3. Among them, in the chemical general formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - xwt% Al2O3, x = 0.3, Al2O3 is a flake template, and the Al2O3 flake templates are arranged directionally in the antiferroelectric ceramic material and perpendicular to the test electrodes.

[0122] A preparation method of a high - energy - storage - density antiferroelectric ceramic material, comprising the following steps:

[0123] The difference from Example 1 is that in step S9, the surface of the sintered ceramic sheet obtained in step S8 perpendicular to the Al2O3 flake template is linearly cut to a thickness of 1 - 1.5 mm, then the upper and lower surfaces of the cut section are polished, ultrasonically cleaned and dried, and gold is sprayed on its upper and lower surfaces to obtain a finished high - energy - storage - density antiferroelectric ceramic material with the Al2O3 flake template perpendicular to the test electrodes.

[0124] Comparative Example 11:

[0125] A high - energy - storage - density antiferroelectric ceramic material with the chemical general formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - 0.1wt% Al2O3, abbreviated as PLZS - 0.1wt% Al2O3. Among them, in the chemical general formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995In O3-xwt% Al2O3, x = 0.1, Al2O3 is a flaky template, and the flaky Al2O3 template is oriented in the antiferroelectric ceramic material and arranged perpendicular to the test electrode.

[0126] A preparation method of a high energy storage density antiferroelectric ceramic material, comprising the following steps:

[0127] The difference from Example 2 is that in step S9, the surface of the sintered ceramic sheet obtained in step S8 perpendicular to the flaky Al2O3 template is linearly cut to a thickness of 1 - 1.5 mm, then the upper and lower surfaces of the cut section are polished, then ultrasonically cleaned and dried, and gold is sprayed on its upper and lower surfaces to obtain a finished high energy storage density antiferroelectric ceramic material with the flaky Al2O3 template arranged perpendicular to the test electrode.

[0128] Comparative Example 12:

[0129] A high energy storage density antiferroelectric ceramic material, with the chemical general formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - 0.5wt% Al2O3, abbreviated as PLZS - 0.5wt% Al2O3, wherein, in the chemical general formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - xwt% Al2O3, x = 0.5, Al2O3 is a flaky template, and the flaky Al2O3 template is oriented in the antiferroelectric ceramic material and arranged perpendicular to the test electrode.

[0130] A preparation method of a high energy storage density antiferroelectric ceramic material, comprising the following steps:

[0131] The difference from Example 3 is that in step S9, the surface of the sintered ceramic sheet obtained in step S8 perpendicular to the flaky Al2O3 template is linearly cut to a thickness of 1 - 1.5 mm, then the upper and lower surfaces of the cut section are polished, then ultrasonically cleaned and dried, and gold is sprayed on its upper and lower surfaces to obtain a finished high energy storage density antiferroelectric ceramic material with the flaky Al2O3 template arranged perpendicular to the test electrode.

[0132] Comparative Example 13:

[0133] A high energy storage density antiferroelectric ceramic material, with the chemical general formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995O3 - 0.7 wt% Al2O3, abbreviated as PLZS - 0.7 wt% Al2O3, where the chemical general formula is (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - x wt% Al2O3, where x = 0.7, Al2O3 is a flaky template, and the Al2O3 flaky templates are arranged directionally and perpendicular to the test electrodes in the antiferroelectric ceramic material.

[0134] A preparation method of a high - energy - storage - density antiferroelectric ceramic material, comprising the following steps:

[0135] The difference from Example 4 is that: in step S9, the surface of the sintered ceramic sheet obtained in step S8 perpendicular to the Al2O3 flaky template is linearly cut to a thickness of 1 - 1.5 mm, then the upper and lower surfaces of the cut section are polished, ultrasonically cleaned and dried, and gold is sprayed on its upper and lower surfaces to obtain the finished high - energy - storage - density antiferroelectric ceramic material with the Al2O3 flaky template arranged perpendicular to the test electrodes.

[0136] Experiment 1

[0137] The Smartlab 3KW produced by Rigaku was used to measure the phase structure of the ceramic materials prepared in Examples 1 - 4 and Comparative Example 1 respectively. Figure 1 is the XRD pattern of the ceramic materials prepared in Examples 1 - 4 and Comparative Example 1. It can be seen from Figure 1 that the prepared ceramic materials are all pure phases. Maybe because the amount of Al2O3 added is too small, the peak of Al2O3 was not detected.

[0138] Experiment 2

[0139] The Phenom ProX produced by Phenom - World BV in the Netherlands was used to test the cross - sections of the ceramic materials prepared in Examples 1 - 4 and Comparative Example 1 respectively. Figure 2 is the SEM pattern of the cross - sections of the ceramic materials prepared in Examples 1 - 4 and Comparative Example 1. Figure 2 In the figure, a - e are the SEM patterns of Comparative Example 1, Example 2, Example 1, Example 3, and Example 4 respectively. Only pure matrix ceramic grains were observed in the SEM pattern of Comparative Example 1. Compared with the pure matrix ceramic of Comparative Example 1, parallel - arranged flaky templates (in the framed area) can be clearly observed in Examples 1 - 4, and as the content of Al2O3 flaky templates in Examples 2, 1, 3, and 4 increases in turn, the number of observed flaky templates also gradually increases.

[0140] To further confirm that the flaky template is Al2O3,Figure 3 EDS spectrum of the ceramic material in Example 1. Through SEM images ( Figure 3 a) and elemental contrast ( Figure 3 b), it was found that Al elements were aggregated on the flaky template, while Pb, La, Zr, Sn, and O elements were uniformly distributed in the matrix ceramic. This indicates that the added Al2O3 flaky template did not dissolve into the matrix ceramic and existed as a second phase in the composite ceramic.

[0141] Experiment 3

[0142] The dielectric properties of the ceramic materials prepared in Examples 1 - 4 and Comparative Example 1 were tested using the E4990A produced by Keysight Technologies, Inc. of the United States, and the changing rules of the influence of Al2O3 on the dielectric properties of the ceramic materials were analyzed. Figure 4 Figure showing the changing rules of the relative dielectric constant (ε r ) of the ceramic materials prepared in Examples 1 - 4 and Comparative Example 1 with temperature. It can be seen that adding a small amount of Al2O3 has no effect on the dielectric properties of the composite material, indicating that adding Al2O3 will not significantly change the electrical properties of the ceramic material.

[0143] Experiment 4

[0144] The ferroelectric properties of the ceramic materials prepared in Examples 1 - 4 and Comparative Examples 1 - 13 were tested using the TF 3000E ferroelectric analyzer produced by aixACCT GmbH of Germany. Figure 5 Figure showing the ferroelectric hysteresis loops of the ceramic materials prepared in Examples 1 - 4 at a test frequency of 10 Hz, Figure 6 Figure showing the ferroelectric hysteresis loops of the ceramic materials prepared in Comparative Examples 1 - 13 at a test frequency of 10 Hz. It can be seen from the figure that the ferroelectric hysteresis loops obtained from the ceramic materials prepared in Examples 1 - 4 and Comparative Examples 1 - 13 all exhibit multi - stage phase transitions. The Al2O3 flaky template exists as a second phase in the antiferroelectric ceramic material composite and does not change the antiferroelectric characteristics of the lead - based ceramic, enabling the achievement of a high breakdown strength while maintaining the multi - stage phase transition characteristics of the matrix ceramic of the antiferroelectric ceramic material. The P r value (remanent polarization) of the ceramic material is small. According to the formula, a small P r value can effectively ensure an increase in the energy storage density value W rec . Under the induction of a high electric field in Examples 1 - 4, due to the antiferroelectric - ferroelectric phase transition, the polarization intensity P can be greatly enhanced. According to

[0145] the formula, an increase in the polarization intensity P can effectively ensure an increase in the energy storage density value W rec .

[0146] Table 1 shows the ferroelectric performance parameters of the ceramic materials prepared in Examples 1-4 and Comparative Examples 1-13. The energy storage density and energy storage efficiency can be calculated according to the following formulas:

[0147]

[0148] Among them, W total is the total energy storage density value; W rec is the releasable energy storage density value; η is the energy storage efficiency; E is the applied electric field strength; P is the polarization intensity; P r is the remanent polarization intensity; P max is the maximum polarization value. The breakdown field strength E of Examples 1-4 b ranges from 480 to 560 kV / cm, and the value of the energy storage density W rec is between 10.31 and 13.5 J / cm 3 . It can be seen from Table 1 that as the content of flaky Al2O3 added in Example 2, Example 1, Example 3, and Example 4 gradually increases, the breakdown strength gradually increases, indicating that adding the flaky Al2O3 template and making it parallel to the test electrode can improve the breakdown strength of the ceramic material, thereby increasing the energy storage density of the antiferroelectric ceramic material.

[0149] However, since Al2O3 is a linear dielectric material with a low polarization intensity, in Example 2, Example 1, Example 3, and Example 4, as the flaky Al2O3 template increases, the polarization intensity of the composite material first increases and then decreases. Therefore, the W rec energy storage density also first increases and then decreases. The maximum energy storage density of 13.5 J / cm 3 is obtained in the PLZS-0.3wt% Al2O3 ceramic material prepared in Example 1. Therefore, x in the present invention cannot be too low or too high. If x is too low, when it is 0, the improvement of the breakdown strength of the ceramic material of the present invention is limited and the energy storage density is too low. If x is too high, greater than 0.7, the maximum polarization intensity of the ceramic material of the present invention will decrease, resulting in a decrease in the energy storage density and efficiency.

[0150] The breakdown strength of the PLZS pure matrix ceramic material prepared in Comparative Example 1 is relatively small, which is 390 kV / cm, and the W rec energy storage density value is 8.74 J / cm 3, the Al2O3 added to the ceramic materials prepared in Comparative Examples 2-5 is granular and randomly arranged in the composite antiferroelectric ceramic material. Compared with the pure matrix ceramic of Comparative Example 1, the ceramic materials prepared in Comparative Examples 2-5 can increase the breakdown electric field of the composite antiferroelectric ceramic material from 390 kV / cm to 450 kV / cm. When the Al2O3 flake templates in the ceramic materials prepared in Comparative Examples 6-9 are randomly arranged in the composite antiferroelectric ceramic material, the breakdown electric field of the composite antiferroelectric ceramic material also increases compared with the pure matrix ceramic material, which is similar to the ceramic materials prepared in Comparative Example 2, and the range is 410-440 kV / cm. When the Al2O3 flake templates in Comparative Examples 10-13 are arranged perpendicular to the test electrodes, their breakdown electric fields do not increase but decrease, even lower than that of the pure matrix ceramic material. The above shows that the morphology and arrangement of Al2O3 in the composite antiferroelectric ceramic material have an important influence on the polarization intensity of the composite antiferroelectric ceramic material, thus affecting the energy storage density of the composite antiferroelectric ceramic material. When the reinforcing phase is the Al2O3 flake template, the energy storage density of the composite antiferroelectric ceramic material can be increased by about 50% at most when the Al2O3 flake templates are oriented and arranged parallel to the test electrodes in the antiferroelectric ceramic material. It can be seen that changing the morphology and arrangement of the reinforcing phase Al2O3 is an effective way to significantly improve the breakdown electric field and energy storage density of the composite antiferroelectric ceramic material. Examples 1-4 prove that when the reinforcing phase Al2O3 is added as a flake template and the flake template is parallel to the test electrodes, the enhancement effect of the breakdown strength of the antiferroelectric ceramic material is the most obvious. The reasons are as follows:

[0151] (1) The Al2O3 flake templates are first prepared by the molten salt method and then tape-cast (also called doctor blading) by the tape-casting process. This tape-casting process can make the Al2O3 flake templates oriented and arranged in the same direction in the antiferroelectric ceramic material matrix. Then, by polishing and sputtering gold on the upper and lower surfaces parallel to the Al2O3 flake templates, the antiferroelectric ceramic material with the Al2O3 flake templates arranged parallel to the test electrodes is obtained, so that the Al2O3 flake templates can effectively disperse the applied electric field in the entire antiferroelectric ceramic material matrix to reduce the non-uniform distribution of the local electric field, which is beneficial to improving the breakdown strength of the antiferroelectric ceramic material and further improving the energy storage density of the antiferroelectric ceramic material.

[0152] Due to the small aspect ratio of the existing granular Al2O3 reinforcement phase, after applying an electric field, the local electric field will concentrate at both ends parallel to the electric field direction, increasing the probability of breakdown behavior. Through the tape casting preparation process, the Al2O3 flake templates are oriented in the same direction in the matrix of the antiferroelectric ceramic material. Then, polishing and gold spraying are carried out on the upper and lower surfaces parallel to the Al2O3 flake templates to obtain an antiferroelectric ceramic material with the Al2O3 flake templates and test electrodes arranged in parallel. Since the flake Al2O3 template is a high-insulation material with the characteristic of high breakdown voltage withstand strength, adding the Al2O3 flake template can increase the resistance of the composite material, thereby increasing the number of bound charges and reducing the movement of free charges. In addition, due to the large aspect ratio of the parallel-aligned Al2O3 flake templates, the applied electric field can be effectively dispersed throughout the matrix of the antiferroelectric ceramic material to alleviate the non-uniform distribution of the local electric field. At the same time, when an electric field is applied, the parallel-aligned Al2O3 flake templates in the composite material can form a relatively wide interfacial potential barrier, which has an obstructive effect on charge carriers, thereby reducing the leakage current and effectively hindering the extension of the electrical tree path, reducing the growth rate of the electrical tree, and even stopping its growth, avoiding the breakdown behavior of the composite material. All of the above are beneficial to improving the breakdown strength of the antiferroelectric ceramic material and further increasing the energy storage density of the antiferroelectric ceramic material.

[0153] (2) After the sufficient stirring step of the tape casting preparation process, adding the second-phase Al2O3 flake template is beneficial to improving the breakdown strength of the antiferroelectric ceramic material composite, and further increasing the energy storage density of the antiferroelectric ceramic material.

[0154] After the sufficient stirring step of the tape casting preparation process, the Al2O3 flake templates are evenly distributed in the antiferroelectric ceramic material. The dielectric constant of Al2O3 is about 10, and (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 solid solution powder ceramics have a dielectric constant of about 500, and the difference in dielectric constants between the two is relatively large. According to the voltage division theory, when an electric field is applied, due to the low dielectric constant of Al2O3, more voltage will accumulate on Al2O3, thus forming a local electric field distribution. The breakdown field strength of Al2O3 itself is relatively high and can withstand a higher electric field intensity, making the voltage that the antiferroelectric ceramic material matrix in the composite material can withstand higher than that of pure ceramics. Therefore, adding the second-phase Al2O3 flake template is beneficial to improving the breakdown strength of the antiferroelectric ceramic material composite and further increasing the energy storage density of the antiferroelectric ceramic material.

[0155] (3) The Al2O3 flake template exists as a second phase in the antiferroelectric ceramic material composite, without changing the antiferroelectric properties of the antiferroelectric ceramic material composite, enabling the characteristics of the multi-stage phase transition of the matrix ceramic of the antiferroelectric ceramic material to be maintained while obtaining a high breakdown strength. Under the induction of a high electric field in the antiferroelectric system of the antiferroelectric ceramic material, due to the antiferroelectric-ferroelectric phase transition, the polarization intensity can be greatly enhanced. According to the formula, with the increase of the polarization intensity P, the value of the energy storage density W rec can be effectively guaranteed to increase.

[0156] Table 1

[0157]

[0158]

[0159] In addition, only some exemplary embodiments of the present invention have been described by way of illustration. Undoubtedly, for those of ordinary skill in the art, various different ways can be used to modify the described embodiments without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A high energy storage density antiferroelectric ceramic material, characterized in that: The chemical general formula is (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 - xwt% Al2O3, where 0 < x ≤ 0.

7. The Al2O3 is a flaky template, and the Al2O3 flaky template is oriented in the same direction in the antiferroelectric ceramic material through a tape casting preparation process, and the Al2O3 flaky template is regulated to be parallel to the test electrode by polishing and spraying gold on the upper and lower surfaces parallel to the Al2O3 flaky template.

2. A high energy storage density antiferroelectric ceramic material, characterized in that: The general chemical formula is (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3-xwt%Al2O3, wherein 0.1≤x≤0.7, the Al2O3 is a sheet template, the Al2O3 sheet template is oriented along the same direction in the antiferroelectric ceramic material through a tape casting preparation process, and the Al2O3 sheet template is regulated to be parallel to the test electrode by polishing and gold spraying on the upper and lower surfaces parallel to the Al2O3 sheet template.

3. A method for preparing a high energy storage density antiferroelectric ceramic material according to claim 1 or 2, comprising the following steps: S1: According to the chemical formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 The stoichiometric ratio of O3-xwt%Al2O3 is prepared according to the proportion of PbO, La2O3, ZrO2, SnO2 powder raw materials, the powder raw materials, anhydrous ethanol solvent and yttrium-stabilized zirconia bead ball milling medium are put into a ball mill, and then dried and sieved to obtain a mixed powder, and the mixed powder is calcined in a high-temperature furnace to synthesize (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 O3 solid solution powder, that is, PLZS solid solution powder; S2: adding anhydrous ethanol solvent and yttrium-stabilized zirconia bead ball milling medium to the PLZS solid solution powder obtained in step S1, and then ball milling, drying, and sieving to obtain PLZS fine powder; S3: adding anhydrous ethanol solvent, butanone solvent, triethyl phosphate dispersant, polybutyral binder, dibutyl phthalate plasticizer, and yttrium-stabilized zirconia bead ball milling medium to the PLZS fine powder obtained in step S2, and then ball milling to obtain a ceramic slurry; S4: In the ceramic slurry obtained in step S3, according to the chemical formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 The stoichiometric ratio of O3-xwt%Al2O3 is added with Al2O3 flake template in proportion, and then stirred in a magnetic stirrer to obtain a mixed slurry; S5: Degassing the mixed slurry obtained in step S4 by stirring and vacuuming using a vacuum degassing machine; S6: casting the mixed slurry obtained in step S5 by a manual casting machine, so that the Al2O3 sheet template is oriented in the same direction in the high energy storage density antiferroelectric ceramic material matrix by casting, and then drying and cutting to obtain a ceramic diaphragm; S7: Laminating the ceramic diaphragm obtained in step S6 in a high energy storage density antiferroelectric ceramic material matrix according to an Al2O3 sheet template and placing it in a mold, heating the mold by a heating sleeve, hot pressing by a manual tablet press, compacting by a cold isostatic press, and then manually cutting to obtain a ceramic green embryo; S8: placing the ceramic green body obtained in step S7 in a muffle furnace for debinding and sintering to obtain a sintered ceramic sheet; S9: polishing and ultrasonically cleaning the upper and lower surfaces of the sintered ceramic sheet obtained in step S8 that are parallel to the Al2O3 sheet template, and drying them, spraying gold on the upper and lower surfaces that are parallel to the Al2O3 sheet template, to obtain a high energy storage density antiferroelectric ceramic material product in which the Al2O3 sheet template and the test electrode are arranged in parallel.

4. The method for preparing a high energy storage density antiferroelectric ceramic material according to claim 3, characterized in that: In the step S7, the ceramic diaphragms obtained in the step S6 are stacked in the same direction according to the Al2O3 sheet template and placed in a mold. The mold is heated by a heating sleeve, hot pressed by a manual tablet press, compacted by a cold isostatic press, and then manually cut to obtain a ceramic green body.

5. The method for preparing a high energy storage density antiferroelectric ceramic material according to claim 3, characterized in that: In the step S4, the ceramic slurry obtained in the step S3 is placed in a beaker, and a stirring magnet is added to the beaker, and then the ceramic slurry is stirred according to the chemical formula (Pb 0.98 La 0.02 )(Zr 0.7 Sn 0.3 ) 0.995 The stoichiometric ratio of O3-xwt%Al2O3 is prepared, and Al2O3 flake template is added in proportion. The mass of the Al2O3 flake template added is xwt% of the mass of the PLZS fine powder in step S2. Then the beaker is placed in a magnetic stirrer and stirred at a speed of 450-600r / min and a stirring time of 24-36h to obtain a mixed slurry.

6. The method for preparing a high energy storage density antiferroelectric ceramic material according to claim 3, characterized in that: In the S1 step, the mass ratio of the anhydrous ethanol solvent to the powder raw material is (0.8-0.9):1, the mass ratio of the yttrium-stabilized zirconia beads to the powder raw material is (4.5-3.5):1, the ball mill speed is 280-300 r / min, the ball milling time is 12-24 h, and then the mixed powder is obtained after drying and sieving. The mixed powder is calcined in a muffle furnace at 800° C. for 2 h to synthesize the PLZS solid solution powder.

7. The method for preparing a high energy storage density antiferroelectric ceramic material according to claim 3, characterized in that: In the S2 step, the mass ratio of the anhydrous ethanol solvent to the PLZS solid solution powder is (0.8-0.9):1, the mass ratio of the yttrium-stabilized zirconia bead ball milling medium to the PLZS solid solution powder is (4.5-3.5):1, the ball milling speed is 280-300 r / min, the ball milling time is 24-36h, and the PLZS fine powder is obtained after drying and sieving.

8. The method for preparing a high energy storage density antiferroelectric ceramic material according to claim 3, characterized in that: In the S3 step, the mass ratio of the anhydrous ethanol solvent to the PLZS fine powder is (4-5):10, the mass ratio of the butanone solvent to the PLZS fine powder is (3-4):10, the mass ratio of the triethyl phosphate dispersant to the PLZS fine powder is (0.2-0.4):10, the mass ratio of the polyethanol butyral adhesive to the PLZS fine powder is (0.6-0.7):10, the mass ratio of the dibutyl phthalate plasticizer to the PLZS fine powder is (0.6-0.7):10, the mass ratio of the yttrium stabilized zirconia beads to the PLZS fine powder is (4.5-3.5):1, the ball milling speed is 280-300r / min, and the ball milling time is 24-36h.

9. The method for preparing a high energy storage density antiferroelectric ceramic material according to claim 3, characterized in that: In the step S4, the mass of the Al2O3 flake template added is (0.1-0.7)% of the mass of the PLZS fine powder in the step S2, the stirring speed of the magnetic stirrer is 450-600 r / min, and the stirring time of the magnetic stirrer is 24-36 h.

10. The method for preparing a high energy storage density antiferroelectric ceramic material according to claim 3, characterized in that: In the step S5, the defoaming time of the vacuum defoamer is 1-2 hours, and the stirring speed is 150-350 r / min.

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