BNT-based lead-free relaxation antiferroelectric ceramic material and preparation method and application thereof

Abstract

The invention relates to a BNT-based lead-free relaxor antiferroelectric ceramic material as well as a preparation method and application of the BNT-based lead-free relaxor antiferroelectric ceramic material. The chemical composition of the BNT-based lead-free relaxation antiferroelectric ceramic material is (Bi < 0.5-x > Pr < x > Na < 0.5 >) TiO < 3 >-0.1 wt% MnCO3, wherein x is mole percent, and x is more than 0.10 and less than or equal to 0.20.

Description

Technical Field

[0001] The present invention belongs to the field of functional ceramics, and in particular relates to a BNT-based lead-free relaxor antiferroelectric ceramic material and a preparation method and application thereof. Background Art

[0002] Energy storage components are crucial components in power devices and electronic devices. Pulsed power technology, characterized by high power, has seen increasing application in defense, nuclear physics, and medical equipment in recent years. Furthermore, with the ongoing new energy revolution and growing emphasis on environmental protection, the power electronics industry, represented by electric vehicle inverters, has also experienced rapid growth. This undoubtedly places higher demands on the performance and production capacity of energy storage components. Dielectric capacitors with higher energy storage density will undoubtedly significantly promote the large-scale integration of electronic power systems. Ceramic dielectric capacitors, owing to their excellent mechanical properties and thermal stability, have become one of the most critical components in pulsed power devices. Lead-based antiferroelectric energy storage ceramics, such as PbZrO3-based ceramics, possess high energy storage density. However, these ceramics contain significant amounts of toxic lead, posing serious risks to the environment and human health during production, preparation, use, and disposal. Therefore, developing new lead-free antiferroelectric energy storage ceramics with superior performance is a crucial technology.

[0003] BNT (Bi 0.5 Na 0.5 CaTiO3) ceramics are a classic lead-free dielectric material and have been widely studied due to their rich phase structure changes and high saturation polarization strength. However, the low breakdown field strength severely limits its application in the field of energy storage. At present, the introduction of linear dielectrics has become an effective method to improve BNT ceramics in view of the low breakdown field strength. For example, the introduction of CaTiO3 into the BNT matrix can greatly improve the breakdown performance, and the breakdown field strength is increased from 203kV / cm to 455kV / cm, and the recoverable energy storage density reaches 2.74J / cm 3 (J.Am.Ceram.Soc.105(6)(2022)4027-4038), however, the energy storage parameters are still low and the dielectric constant decreases significantly, which cannot meet the needs of practical applications. How to effectively improve the energy storage properties of BNT remains a hot and difficult research topic. Summary of the Invention

[0004] In view of the above technical problems, the purpose of the present invention is to provide a BNT-based lead-free relaxor antiferroelectric ceramic material for energy storage, a preparation method thereof, and an application thereof in the preparation of ceramic components.

[0005] In the first aspect, the present invention provides a BNT-based lead-free relaxor antiferroelectric ceramic material, the chemical composition of the BNT-based lead-free relaxor antiferroelectric ceramic material is (Bi0.5-x Pr x Na 0.5 )TiO3-0.1wt%MnCO3; wherein, x is a molar percentage, 0.10<x≤0.20.

[0006] Preferably, the BNT-based lead-free relaxor antiferroelectric ceramic material has a relative dielectric constant of 700-900 at a test frequency of 1 kHz at 25°C, a dielectric loss of <0.05, and an energy storage density of 8-11 Jcm -3 , the energy storage efficiency is 80-90%.

[0007] In a second aspect, the present invention provides a method for preparing a BNT-based lead-free relaxor antiferroelectric ceramic material, comprising: (1) mixing a Bi source, a Pr source, a Na source, and a Ti source according to the chemical composition ratio of the BNT-based lead-free relaxor antiferroelectric ceramic material for the first time, drying the mixture for the first time, and screening the mixture for the first time, and calcining the mixture to obtain a ceramic pre-solid solution powder; (2) adding a Mn source to the ceramic early solid solution powder according to the chemical composition ratio of the BNT-based lead-free relaxor antiferroelectric ceramic material, performing a second mixing, a second drying, and a second screening to obtain a ceramic final solid solution powder; (3) adding a binder to the final ceramic solid solution powder and granulating the powder, and then aging, molding and discharging the powder to obtain a BNT-based lead-free relaxor antiferroelectric ceramic green body; (4) After sintering, the BNT-based lead-free relaxor antiferroelectric ceramic material is obtained.

[0008] Preferably, the Bi source is Bi2O3, and the Pr source is Pr6O 11 , the Na source is NaHCO3, the Ti source is TiO2, and the Mn source is MnCO3.

[0009] Preferably, the first mixing method is ball milling, the mass ratio of raw materials: grinding balls: alcohol is controlled to be 1: (4-8): (0.8-1.3), the grinding balls are zirconia balls, zirconia columns, agate balls, and the ball milling time is 24-48 hours; The mesh number of the first screening is 20 to 80 meshes.

[0010] Preferably, the calcination temperature is 600-1200°C, preferably 800-1200°C, more preferably 800-1000°C; the calcination time is less than 24 hours, preferably 1-24 hours, more preferably 2-5 hours; the heating rate is not higher than 2°C / min.

[0011] Preferably, the second mixing method is ball milling, the mass ratio of raw materials: grinding balls: alcohol is controlled to be 1: (4-8): (0.6-1.2), the grinding balls are zirconia balls, zirconia columns, agate balls, and the ball milling time is 24-48 hours; The mesh number of the second screening is 20 to 80 meshes.

[0012] Preferably, the binder is at least one of polyvinyl alcohol, polyethylene glycol, polystyrene or methyl cellulose, the concentration of the binder is 6-8%, and the added amount is 6-8wt% of the mass of the final ceramic solid solution powder.

[0013] Preferably, the aging temperature is room temperature, and the aging time is 18 to 26 hours, preferably 22 to 26 hours; The temperature of the plastic discharge is 650-850°C, the holding time is 1-24 hours, preferably 2-6 hours, and the heating rate of the plastic discharge is not higher than 2°C / min; The sintering temperature is 1000-1400°C, preferably 1000-1300°C, more preferably 1100-1300°C; the sintering time is less than 24 hours, preferably 1-24 hours, more preferably 2-6 hours; the heating rate is not higher than 2°C / minute.

[0014] In a third aspect, the present invention provides an application of the above-mentioned BNT-based lead-free relaxor antiferroelectric ceramic material in the preparation of ceramic capacitors and dielectric capacitors in high-power pulse systems.

[0015] Beneficial effects The ceramic material provided by the present invention has simple composition and is easy to prepare. By doping with the Pr element, the long-range order of BNT is broken, a relaxed antiferroelectric phase is induced at room temperature, the residual polarization intensity is reduced, and the energy storage efficiency is improved. At the same time, it has a higher breakdown field strength and maximum polarization intensity. Compared with existing materials, this component has both higher energy storage density and energy storage efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Example 1 (Bi 0.32 Pr 0.18 Na 0.5 )TiO3-0.1wt%MnCO3, Example 2 (Bi 0.30 Pr 0.20 Na 0.5 )TiO3-0.1wt%MnCO3, Comparative Example 1 (Bi 0.45 Pr 0.05 Na 0.5 )TiO3-0.1wt%MnCO3, Comparative Example 2 (Bi 0.40 Pr 0.10 Na0.5 )TiO3-0.1wt%MnCO3, Comparative Example 3 (Bi 0.20 Pr 0.30 Na0 .5 ) X-ray diffraction pattern of ceramic material prepared in TiO3-0.1wt% MnCO3; Figure 2 Surface micromorphology of the ceramic materials prepared in Example 1, Example 2, Comparative Example 1, Comparative Example 2, and Comparative Example 3 of the present invention; Figure 3 1 is a comparison diagram of the hysteresis loops of the ceramic components prepared in Example 1, Example 2, Comparative Example 1, Comparative Example 2 and Comparative Example 3 of the present invention. DETAILED DESCRIPTION

[0017] The present invention is further described below through the following embodiments. It should be understood that the following embodiments are only used to illustrate the present invention, rather than to limit the present invention.

[0018] First, the present invention provides a BNT-based lead-free relaxor antiferroelectric ceramic material. The chemical composition of the BNT-based lead-free relaxor antiferroelectric ceramic material can be (Bi 0.5-x Pr x Na 0.5 )TiO3-0.1wt%MnCO3; wherein, x is a molar percentage, 0.10<x≤0.20.

[0019] Through theoretical research and multiple experimental verifications, this invention addresses the ferroelectricity of BNT-based ceramics. Considering the smaller ionic radius of Pr compared to Bi, the antiferroelectricity is enhanced by reducing the system tolerance factor. This simultaneously increases the disorder of the A-site ions, disrupting the long-range ferroelectric order in BNT, reducing the domain size to the nanometer level, and improving the ceramic's relaxivity. Furthermore, the coexistence of Pr with +3 and +4 valences in the system inhibits the formation of oxygen vacancies, reduces system defects, and enhances the breakdown field strength.

[0020] Furthermore, by doping with the element Pr, antiferroelectric properties can be induced. The ceramic material with the chemical composition provided by the present invention exhibits a typical hysteresis loop waist phenomenon, exhibiting relaxed antiferroelectric characteristics, and possesses high saturation polarization, low remanent polarization, and high energy storage density and efficiency, promising applications in the field of dielectric energy storage.

[0021] Among them, if the value of x is too large, the linear characteristics of the material will be enhanced. Although the material can have a higher breakdown field strength, the maximum polarization intensity P max will be greatly reduced, and the energy storage density will be reduced; if the value of x is too small, the ferroelectric properties of the material will be stronger, the antiferroelectric properties will be weakened, and the residual polarization intensity P r The larger the value, the lower the energy storage efficiency.

[0022] In some embodiments, the BNT-based lead-free relaxor antiferroelectric ceramic material has a relative dielectric constant of 700 to 900 at a test frequency of 1 kHz at 25°C, a dielectric loss of less than 0.05 (preferably a dielectric loss of less than 0.015), and an energy storage density of 8 to 11 J cm -3 , the energy storage efficiency is 80-90%.

[0023] The following is an exemplary description of the preparation method of the BNT-based lead-free relaxor antiferroelectric ceramic material provided by the present invention. The preparation method may include the following steps: First, Bi source, Pr source, Na source, and Ti source are mixed, dried, and sieved according to the chemical composition ratio of the BNT-based lead-free relaxor antiferroelectric ceramic material, calcined, and cooled to room temperature in the furnace to obtain a ceramic pre-solid solution powder; Then, a Mn source is added to the ceramic preliminary solid solution powder according to the chemical composition ratio of the BNT-based lead-free relaxor antiferroelectric ceramic material, and a ceramic final solid solution powder is obtained through a second mixing, a second drying, and a second screening. Then, a binder is added to the ceramic final solid solution powder and granulated, and a BNT-based lead-free relaxor antiferroelectric ceramic green body is obtained through aging, molding, and plastic removal. Finally, the BNT-based lead-free relaxor antiferroelectric ceramic material is obtained through sintering.

[0024] In some embodiments, the Bi source may be Bi2O3, and the Pr source may be Pr6O 11 , the Na source may be NaHCO3, the Ti source may be TiO2, and the Mn source may be MnCO3.

[0025] In some embodiments, the first mixing method can be ball milling mixing, and the mass ratio of raw materials: grinding balls: alcohol can be controlled to be 1: (4 to 8): (0.8 to 1.3). The grinding balls can be zirconia balls, zirconia columns, or agate balls, and the ball milling time can be 24 to 48 hours.

[0026] In some embodiments, the mesh size of the first screening may be 20 to 80 meshes.

[0027] In some embodiments, the calcination temperature can be 600-1200°C, preferably 800-1200°C, and more preferably 800-1000°C; the calcination time can be less than 24 hours, preferably 1-24 hours, and more preferably 2-5 hours; the heating rate can be controlled to be no higher than 2°C / min, so that the synthesis reaction of the BNT ceramic occurs fully.

[0028] In some embodiments, the powder can be briquetteed at 100-300 MPa after the first screening, and then the pressed block is calcined and synthesized in a closed container (e.g., a closed alumina crucible), thereby reducing the volatilization of Bi and Na components and slag contamination; at the same time, the block can be further crushed and sieved (e.g., 20-80 mesh) after synthesis, thereby improving the efficiency of subsequent mixing processes such as ball milling and saving preparation time.

[0029] In some embodiments, the second mixing method can be ball milling mixing, and the mass ratio of raw materials: grinding balls: alcohol can be controlled to be 1: (4 to 8): (0.6 to 1.2). The grinding balls can be zirconia balls, zirconia columns, or agate balls, and the ball milling time can be 24 to 48 hours.

[0030] In some embodiments, the mesh size of the second screening may be 20 to 80 meshes.

[0031] In some embodiments, the binder may be at least one of polyvinyl alcohol, polyethylene glycol, polystyrene or methyl cellulose, the concentration of the binder may be 6-8%, and the amount added may be 6-8 wt % of the mass of the final ceramic solid solution powder.

[0032] Aging can make the adhesive more evenly distributed in the powder, which helps the powder to be better formed. In some embodiments, the aging temperature can be room temperature (25° C.) and the time can be 18 to 26 hours, preferably 22 to 26 hours.

[0033] In some embodiments, the forming may be performed by dry pressing, and the forming pressure may be 100 to 300 MPa.

[0034] In some embodiments, the temperature of the plastic discharge can be 650-850° C., and the holding time can be 1-24 hours, preferably 2-6 hours; preferably, the heating rate of the plastic discharge is not higher than 2° C. / min.

[0035] In some embodiments, the sintering temperature can be 1000-1400°C, preferably 1000-1300°C, and more preferably 1100-1300°C; the sintering time can be less than 24 hours, preferably 1-24 hours, and more preferably 2-6 hours; the heating rate can be no higher than 2°C / minute, so that the ceramic is easy to form without causing component segregation.

[0036] According to the preparation process of the present invention, by controlling the mixing time and the fine grinding time to be within 24 hours and 48 hours respectively, a ceramic sample with an average grain size of 10 to 30 μm is obtained.

[0037] The technical solution provided by the present invention has a simple preparation process, and the obtained BNT-based lead-free relaxor antiferroelectric ceramic material has a simple composition. The BNT-based lead-free relaxor antiferroelectric ceramic prepared by component regulation and process optimization has the characteristics of high withstand voltage strength, low residual polarization strength and high saturation polarization strength, high energy storage density and energy storage efficiency, and has typical waist hysteresis loop characteristics at room temperature. It is suitable for the preparation of BNT-based lead-free relaxor antiferroelectric ceramic components such as ceramic capacitors and dielectric capacitors in high-power pulse systems.

[0038] As an example, the BNT-based lead-free relaxor antiferroelectric ceramic material is processed into a desired size, cleaned (e.g., ultrasonically cleaned), dried, silvered, and silver-sintered to obtain a BNT-based relaxor antiferroelectric ceramic element. The silver-sintering conditions may be a temperature of 600-900°C for 10-30 minutes, with a heating rate of no more than 2°C / minute.

[0039] The following examples are further given to illustrate the present invention in detail. It should also be understood that the following examples are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention all fall within the scope of protection of the present invention. The specific process parameters and the like in the following examples are only examples within a suitable range, that is, those skilled in the art can make selections within a suitable range through the description herein, and are not limited to the specific numerical values ​​exemplified below.

[0040] Example 1

[0041] BNT-based lead-free relaxor antiferroelectric ceramic materials (Bi 0.5-x Pr x Na 0.5 )TiO3-0.1wt%MnCO3, x=0.18) preparation method comprises the following steps: (1) According to the chemical composition ratio, 99.999% pure bismuth oxide, 99.9% pure praseodymium oxide, 99.5% pure sodium bicarbonate, and 99.8% pure titanium oxide were weighed using an electronic balance (weighing accuracy to 0.001g), and the weighed raw materials were mixed and placed in a nylon can. Anhydrous ethanol was added to the can. The nylon can was placed on a planetary ball mill with zirconia columns and zirconia balls of different sizes as the medium for mixing. The zirconia columns included two different sizes with a diameter of 15m. m×15mm high and 7.5mm diameter×7.5mm high, the zirconia balls include one size: 10mm diameter, and the mass ratio of the three zirconia columns and balls is 4:2:3. After ball milling, the mixture is poured out and dried in a baking oven, and then sieved with a 40-mesh nylon sieve. The sieved mixed powder is pressed into a cylindrical block with a size of 65mm diameter×20mm high on a press, synthesized at 850℃ for 4 hours, and then crushed through a 40-mesh sieve to obtain a ceramic early solid solution powder; (2) placing the obtained ceramic preliminary solid solution powder back into a nylon can, adding 0.1% of the powder weight of manganese carbonate powder according to a stoichiometric ratio, adding anhydrous ethanol to the can to a level not higher than 2 / 3 of the can height, placing the nylon can on a planetary ball mill using zirconia columns and zirconia balls of different sizes as a medium for mixing, then pouring out and drying in a baking oven, and then sieving with a 40-mesh nylon sieve to obtain a ceramic final solid solution powder; (3) adding a polyvinyl alcohol aqueous solution with a concentration of 7 wt.% to the final ceramic solid solution powder (ground ceramic powder), wherein the amount of the polyvinyl alcohol aqueous solution added is 6% of the mass of the ceramic powder, and then uniformly granulating the powder, passing it through a 40-mesh sieve, aging, and compression molding to obtain a small cylinder with a size of 13 mm in diameter and 1 mm in height, and then performing plasticizing; sintering the obtained green body after plasticizing in an atmospheric atmosphere at a sintering temperature of 1250° C. for a holding time of 4 hours, and naturally cooling it to room temperature to obtain the BNT-based lead-free relaxor antiferroelectric ceramic material; The BNT-based lead-free relaxor antiferroelectric ceramic material is processed, cleaned, dried and electroded to obtain a ceramic component.

[0042] Example 2

[0043] The preparation method of the BNT-based lead-free relaxor antiferroelectric ceramic material in this embodiment refers to that in Example 1, the main difference is that the molecular formula of the BNT-based lead-free relaxor antiferroelectric ceramic material is (Bi 0.5-x Pr x Na 0.5 )TiO3-0.1wt%MnCO3, x=0.20.

[0044] Comparative Example 1

[0045] The preparation method of the ceramic material in this comparative example refers to that in Example 1, the main difference is that the molecular formula of the ceramic material is (Bi 0.5-x Pr x Na 0.5 )TiO3-0.1wt%MnCO3, x=0.05.

[0046] Comparative Example 2

[0047] The preparation method of the ceramic material in this comparative example refers to that in Example 1, the main difference is that the molecular formula of the ceramic material is (Bi 0.5-x Pr x Na 0.5 )TiO3-0.1wt%MnCO3, x=0.10.

[0048] Comparative Example 3

[0049] The preparation method of the ceramic material in this comparative example refers to that in Example 1, the main difference is that the molecular formula of the ceramic material is (Bi 0.5-x Pr x Na 0.5 )TiO3-0.1wt%MnCO3, x=0.30.

[0050] Figure 1 Example 1 (Bi 0.32 Pr 0.18 Na 0.5 )TiO3-0.1wt%MnCO3, Example 2 (Bi 0.30 Pr 0.20 Na 0.5 )TiO3-0.1wt%MnCO3, Comparative Example 1 (Bi 0.45 Pr 0.05 Na 0.5 )TiO3-0.1wt%MnCO3, Comparative Example 2 (Bi 0.40 Pr 0.10 Na 0.5 )TiO3-0.1wt%MnCO3, Comparative Example 3 (Bi 0.20 Pr 0.30 Na0 .5 ) X-ray diffraction pattern of the ceramic material prepared in TiO3-0.1wt% MnCO3. As can be seen from the figure, the Pr-doped BNT ceramics prepared by the preparation method provided by the present invention have no impurity phase.

[0051] Figure 2The following are surface micromorphologies of the ceramic materials prepared in Examples 1 and 2, Comparative Examples 1, 2, and 3 of the present invention. As can be seen from the figures, the ceramic materials prepared using the preparation method provided by the present invention are sintered densely. The grains of Examples 1, 2, and the comparative example are well-developed and have high density. The particle sizes of Examples 1 and 2 range from 1 to 40 μm, with the majority concentrated around 20 μm.

[0052] The prepared ceramic components were subjected to unipolar hysteresis loop tests at room temperature and 10 Hz. Figure 3 The hysteresis loop comparison diagram of the ceramic components prepared in Example 1, Example 2, Comparative Example 1, Comparative Example 2 and Comparative Example 3 of the present invention is shown in the figure. As can be seen from the figure, the energy storage density of the ceramic components prepared in Examples 1 and 2 increases continuously with the increase of the electric field, and the maximum energy storage density is 11.0 J / cm 3 and 8.2 J / cm 3 , the energy storage efficiency is 86.8% and 85.4% respectively, while the energy storage density and energy storage efficiency of comparative example 1 are 3J / cm 3 , 62.5%, and the energy storage density and energy storage efficiency of comparative example 2 were 7.3 J / cm 3 , 71.6%, and the energy storage density and energy storage efficiency of comparative example 3 were 4.8 J / cm 3 , 87.3%; and with the increase of Pr content, the antiferroelectric properties of the system first increase and then weaken. When the Pr content reaches 0.30, the ceramic has gradually transformed from an antiferroelectric structure to a paraelectric structure. At the same time, with the increase of Pr content, its saturation polarization intensity first increases and then gradually decreases, indicating that with the increase of Pr content, its antiferroelectric properties first increase and then weaken, and the BNT-based ceramics transform from antiferroelectric properties to paraelectric properties.

[0053] Table 1 below lists the performance parameters of Example 1, Example 2, Comparative Examples 1, 2, and 3. Examples 1 and 2 both exhibit high energy storage density and efficiency. By comparison, Examples 1 and 2 exhibit higher energy storage characteristics than Comparative Examples 1, 2, and 3, making them more suitable for application in pulse power capacitor technology. Table 1: Comparison of energy storage performance of BNT-based ceramics with different Pr contents <![CDATA[Recoverable energy storage density Wrec (J / cm 3 )]]> Energy storage efficiency η(%) Example 1 x＝0.18 11.0 86.8 Example 2 x＝0.20 8.2 85.4 Comparative Example 1 x＝0.05 3.0 62.5 Comparative Example 2 x＝0.10 7.3 71.6 Comparative Example 3 x＝0.30 4.8 87.3

[0054] In summary, the embodiments of the present invention constitute a simple BNT-based relaxor antiferroelectric ceramic component, and induce relaxation behavior in the BNT-based ceramic ferroelectric phase by doping with the Pr element, thereby greatly improving the energy storage performance of the BNT-based ceramic, and are suitable for the preparation and application of ceramic capacitors and dielectric capacitors in high-power pulse systems.

[0055] Although the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description is not intended to limit the present invention. After reading the above description, various modifications and substitutions of the present invention will become apparent to those skilled in the art. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A BNT-based lead-free relaxor antiferroelectric ceramic material, characterized in that: The chemical composition of the BNT-based lead-free relaxor antiferroelectric ceramic material is (Bi 0.5-x Pr x Na 0.5 )TiO3-0.1wt%MnCO3; wherein, x is a molar percentage, 0.10<x≤0.

20.

2. The BNT-based lead-free relaxor antiferroelectric ceramic material according to claim 1, characterized in that: The BNT-based lead-free relaxor antiferroelectric ceramic material has a relative dielectric constant of 700-900 at a test frequency of 25° C. and 1 kHz, a dielectric loss of less than 0.05, and an energy storage density of 8-11 J cm -3 , the energy storage efficiency is 80-90%.

3. A method for preparing the BNT-based lead-free relaxor antiferroelectric ceramic material according to claim 1 or 2, characterized in that: include: (1) mixing, drying, and sieving Bi, Pr, Na, and Ti sources according to the chemical composition ratio of the BNT-based lead-free relaxor antiferroelectric ceramic material according to claim 1 or 2, and calcining to obtain a ceramic pre-solid solution powder; (2) adding a Mn source to the ceramic preliminary solid solution powder according to the chemical composition ratio of the BNT-based lead-free relaxor antiferroelectric ceramic material according to claim 1 or 2, and performing a second mixing, a second drying, and a second screening to obtain a ceramic final solid solution powder; (3) adding a binder to the final ceramic solid solution powder and granulating the powder, and then aging, molding and discharging the powder to obtain a BNT-based lead-free relaxor antiferroelectric ceramic green body; (4) After sintering, the BNT-based lead-free relaxor antiferroelectric ceramic material is obtained.

4. The preparation method according to claim 3, characterized in that The Bi source is Bi2O3, and the Pr source is Pr6O 11 , the Na source is NaHCO3, the Ti source is TiO2, and the Mn source is MnCO3.

5. The preparation method according to claim 3 or 4, characterized in that The first mixing method is ball milling, the mass ratio of raw materials: grinding balls: alcohol is controlled to be 1: (4-8): (0.8-1.3), the grinding balls are zirconia balls, zirconia columns, and agate balls, and the ball milling time is 24-48 hours; The mesh number of the first screening is 20 to 80 meshes.

6. The preparation method according to any one of claims 3 to 5, characterized in that The calcination temperature is 600-1200°C, preferably 800-1200°C, more preferably 800-1000°C; the calcination time is less than 24 hours, preferably 1-24 hours, more preferably 2-5 hours; the heating rate is not higher than 2°C / min.

7. The preparation method according to any one of claims 3 to 6, characterized in that The second mixing method is ball milling, the mass ratio of raw materials: grinding balls: alcohol is controlled to be 1: (4-8): (0.6-1.2), the grinding balls are zirconia balls, zirconia columns, and agate balls, and the ball milling time is 24-48 hours; The mesh number of the second screening is 20 to 80 meshes.

8. The preparation method according to any one of claims 3 to 7, characterized in that The binder is at least one of polyvinyl alcohol, polyethylene glycol, polystyrene or methyl cellulose, the concentration of the binder is 6-8%, and the added amount is 6-8wt% of the mass of the final ceramic solid solution powder.

9. The preparation method according to any one of claims 3 to 8, characterized in that The aging temperature is room temperature, and the time is 18 to 26 hours, preferably 22 to 26 hours; The temperature of the plastic discharge is 650-850°C, the holding time is 1-24 hours, preferably 2-6 hours, and the heating rate of the plastic discharge is not higher than 2°C / min; The sintering temperature is 1000-1400°C, preferably 1000-1300°C, more preferably 1100-1300°C; the sintering time is less than 24 hours, preferably 1-24 hours, more preferably 2-6 hours; the heating rate is not higher than 2°C / minute.

10. Use of the BNT-based lead-free relaxor antiferroelectric ceramic material according to claim 1 or 2 in the preparation of ceramic capacitors and dielectric capacitors in high-power pulse systems.

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