A barium titanate-based ceramic material with high energy storage density and a preparation method thereof

Abstract

The application relates to the energy storage technical field of dielectric ceramic materials, in particular to a barium titanate-based ceramic material with high energy storage density and a preparation method. First, BaCO3, TiO2, Bi2O3, MgO, ZnO and Na2CO3 are pre-sintered and heat-preserved to obtain a barium titanate-based ceramic powder, the barium titanate-based ceramic powder is put into a ball mill tank for pretreatment, a green body is pre-sintered to obtain a first product, the first product is poured into a ball mill tank for mixing and separation, a mold is used to press the obtained powder to obtain a round sheet, the round sheet is sintered in a muffle furnace according to sintering conditions, and the barium titanate-based ceramic material with high energy storage density is obtained. By introducing strong ferroelectrics Bi(Mg 1 / 4 Zn 1 / 4 Ti 1 / 2 )O3 and (Bi 0.5 Na 0.5 )TiO3 and BaTiO3 antiferroelectrics to form a uniform solid solution, the maximum polarization strength and the breakdown field strength of the ceramic material are improved, the energy storage density of the dielectric ceramic material is improved, and the problem that the energy storage density of the existing dielectric ceramic material is low is solved.

Description

Technical Field

[0001] This invention relates to the field of energy storage technology for dielectric ceramic materials, and particularly to a high energy density barium titanate-based ceramic material and its preparation method. Background Technology

[0002] Energy storage typically employs fuel cells and lithium-ion batteries; however, dielectric capacitors offer advantages such as ultrafast charge / discharge rates and ultra-high power density compared to fuel cells and lithium-ion batteries, and are therefore extensively studied. Generally, key factors for achieving high energy storage density are high saturation polarization, high breakdown strength, and low remanent polarization.

[0003] Currently, there are four representative dielectric materials used in energy storage applications: linear dielectrics, ferroelectrics, relaxor ferroelectrics, and antiferroelectrics. Among them, linear dielectric materials have high breakdown strength and low remanent polarization, but their low high saturation polarization limits their application in high-energy storage.

[0004] However, the energy storage density of existing dielectric ceramic materials is low and cannot meet market demand. Summary of the Invention

[0005] The purpose of this invention is to provide a barium titanate-based ceramic material with high energy storage density and its preparation method, which solves the problem of low energy storage density of existing dielectric ceramic materials.

[0006] To achieve the above objectives, the present invention provides a method for preparing barium titanate-based ceramic materials with high energy storage density, comprising the following steps:

[0007] The raw materials are pre-fired and kept at a constant temperature to obtain barium titanate-based ceramic powder;

[0008] The barium titanate-based ceramic powder is pretreated and then pressed and pre-fired to obtain the first product.

[0009] The first product is mixed and separated to obtain powder, and the powder is pressed with a mold to obtain a disc;

[0010] The discs are sintered to obtain a barium titanate-based ceramic material with high energy storage density.

[0011] The step of pre-firing and holding the raw materials to obtain barium titanate-based ceramic powder further includes:

[0012] The raw materials are BaCO3, TiO2, Bi2O3, MgO, ZnO and Na2CO3.

[0013] The step of pre-firing and holding the raw materials to obtain barium titanate-based ceramic powder further includes:

[0014] BaCO3 and TiO2 were mixed and pre-fired and kept at a certain temperature to obtain the main crystalline phase of BaTiO3;

[0015] Bi₂O₃, MgO, ZnO, and TiO₂ were mixed and pre-calcined at a certain temperature to obtain Bi(MgO)₂. 1 / 4 Zn 1 / 4 Ti 1 / 2 O3 main crystal phase;

[0016] Bi₂O₃, Na₂CO₃, and TiO₂ are mixed and pre-calcined at a constant temperature to obtain (Bi 0.5 Na 0.5 TiO3 main crystal phase;

[0017] The BaTiO3 main crystal phase and the Bi(Mg) 1 / 4 Zn 1 / 4 Ti 1 / 2 The O3 main crystalline phase was mixed and pre-fired at a certain temperature to obtain 0.9BaTiO3-0.1Bi(Mg) 1 / 4 Zn 1 / 4 Ti 1 / 2 O3 main crystal phase;

[0018] The 0.9BaTiO3-0.1Bi(Mg) 1 / 4 Zn 1 / 4 Ti 1 / 2 O3 main crystal phase and the (Bi) 0.5 Na 0.5 The TiO3 main crystalline phase is mixed and pre-fired and kept at a certain temperature to obtain barium titanate-based ceramic powder.

[0019] The process includes pretreating the barium titanate-based ceramic powder, followed by pressing and pre-firing to obtain the first product. The steps further include:

[0020] The barium titanate-based ceramic powder, zirconium oxide spheres, and anhydrous ethanol were mixed in a certain mass ratio to obtain a mixed product.

[0021] After ball milling the mixture for 4 hours, it was rapidly dried at a set temperature to obtain a dried product.

[0022] The dried product is passed through a sieve to separate the zirconia balls, thus obtaining the first product.

[0023] The process includes mixing and separating the first product to obtain powder, and pressing the powder into discs using a mold. The steps further include:

[0024] Polyvinyl alcohol was added to the first product for granulation to obtain a first product with fine particle size.

[0025] The fine-particle-size first product is pressed through a mold to obtain a disc.

[0026] The pre-firing temperature for the pre-firing and heat preservation is 720-850℃, and the heat preservation time is 4-6h. The sintering temperature is 1200-1300℃, and the heat preservation time is 2h.

[0027] A high-energy-density barium titanate-based ceramic material, wherein the high-energy-density barium titanate-based ceramic material comprises BaCO3, TiO2, Bi2O3, MgO, ZnO and Na2CO3.

[0028] This invention discloses a high-energy-density barium titanate-based ceramic material and its preparation method. First, BaCO3, TiO2, Bi2O3, MgO, ZnO, and Na2CO3 are pre-fired and held at a certain temperature to obtain barium titanate-based ceramic powder. This powder is then pre-treated in a ball mill jar, followed by pressing and pre-firing to obtain a first product. The first product is then poured into a ball mill jar for mixing and separation. The obtained powder is pressed using a mold to obtain discs. These discs are then sintered in a muffle furnace under specific sintering conditions to obtain a high-energy-density barium titanate-based ceramic material. This is achieved by introducing a strong ferroelectric material, Bi(MgO)2O3, into the ceramic material. 1 / 4 Zn 1 / 4 Ti 1 / 2 )O3 and (Bi 0.5 Na 0.5 TiO3 and BaTiO3 antiferroelectrics form a uniform solid solution to improve the maximum polarization intensity and breakdown field strength of ceramic materials, thereby increasing the energy storage density of dielectric ceramic materials and solving the problem of low energy storage density of existing dielectric ceramic materials. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0030] Figure 1 This is a flowchart illustrating the steps of the method for preparing the high energy density barium titanate-based ceramic material of the present invention.

[0031] Figure 2 This is a flowchart illustrating the steps of the present invention to pre-fire and heat-keep the raw materials to obtain barium titanate-based ceramic powder.

[0032] Figure 3 The diagram shows the steps of the present invention to pretreat the barium titanate-based ceramic powder and then press and pre-fire it to obtain the first product.

[0033] Figure 4 The present invention describes the steps of mixing and separating the first product to obtain powder, and pressing the powder with a mold to obtain a disc. Detailed Implementation

[0034] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention.

[0035] The first embodiment of this application is as follows:

[0036] Please see Figures 1 to 4 ,in, Figure 1 This is a flowchart illustrating the steps of the method for preparing the high energy density barium titanate-based ceramic material of the present invention. Figure 2 This is a flowchart illustrating the steps of the present invention to pre-fire and heat-keep the raw materials to obtain barium titanate-based ceramic powder. Figure 3 The diagram shows the steps of the present invention to pretreat the barium titanate-based ceramic powder and then press and pre-fire it to obtain the first product. Figure 4 This invention provides a method for preparing barium titanate-based ceramic materials with high energy storage density, comprising the following steps: (1) Mixing and separating the first product to obtain powder, and then pressing the powder with a mold to obtain a disc.

[0037] S101: Pre-fire and heat-insulate the raw materials to obtain barium titanate-based ceramic powder;

[0038] S1011: BaCO3 and TiO2 are mixed and pre-fired and kept at a certain temperature to obtain the main crystalline phase of BaTiO3;

[0039] S1012: Bi₂O₃, MgO, ZnO, and TiO₂ are mixed and pre-calcined at a certain temperature to obtain Bi(MgO)₂. 1 / 4 Zn 1 / 4 Ti 1 / 2 O3 main crystal phase;

[0040] S1013: Bi₂O₃, Na₂CO₃, and TiO₂ are mixed and pre-calcined at a constant temperature to obtain (Bi 0.5 Na 0.5 TiO3 main crystal phase;

[0041] S1014: The BaTiO3 main crystal phase and the Bi(Mg)2 1 / 4 Zn 1 / 4 Ti 1 / 2 The O3 main crystalline phase was mixed and pre-fired at a certain temperature to obtain 0.9BaTiO3-0.1Bi(Mg) 1 / 4 Zn 1 / 4 Ti 1 / 2 O3 main crystal phase;

[0042] S1015: The 0.9BaTiO3-0.1Bi(Mg) 1 / 4 Zn 1 / 4 Ti 1 / 2 O3 main crystal phase and the (Bi) 0.5 Na 0.5 The TiO3 main crystalline phase is mixed and pre-fired and kept at a certain temperature to obtain barium titanate-based ceramic powder.

[0043] Specifically, the raw materials are BaCO3, TiO2, Bi2O3, MgO, ZnO, and Na2CO3. The sintering conditions are a temperature of 1200-1300℃ and a holding time of 2 hours. BaCO3 and TiO2, weighed according to stoichiometric ratios, are mixed and pre-fired at this temperature to obtain the BaTiO3 main crystalline phase. Bi2O3, MgO, ZnO, and TiO2, weighed according to stoichiometric ratios, are mixed and pre-fired at this temperature to obtain Bi(MgO)2O3. 1 / 4Zn 1 / 4 Ti 1 / 2 The main crystalline phase is Bi₂O₃. Bi₂O₃, Na₂CO₃, and TiO₂ are weighed according to stoichiometric ratios, mixed, pre-calcined, and held at a certain temperature to obtain (Bi₂O₃)₂O₃. 0.5 Na 0.5 The main crystalline phase is TiO3. BaTiO3 and Bi(Mg) are weighed according to stoichiometric ratios. 1 / 4 Zn 1 / 4 Ti 1 / 2 After mixing with O3 and pre-calcining and maintaining the temperature, 0.9BaTiO3-0.1Bi(Mg) was obtained. 1 / 4 Zn 1 / 4 Ti 1 / 2 The main crystalline phase is BaTiO3, and 0.9% of the stoichiometric amount of the mixture is added to form BaTiO3-0.1% Bi(Mg)O3. 1 / 4 Zn 1 / 4 Ti 1 / 2 O3 and the (Bi) 0.5 Na 0.5 TiO3 was mixed and pre-fired and kept at a certain temperature to obtain barium titanate-based ceramic powder.

[0044] S102: The barium titanate-based ceramic powder is pretreated and then pressed and pre-fired to obtain the first product;

[0045] S1021: The barium titanate-based ceramic powder, zirconium oxide spheres and anhydrous ethanol are mixed in a mass ratio to obtain a mixed product;

[0046] S1022: After ball milling the mixture for 4 hours, it is rapidly dried at a set temperature to obtain a dried product;

[0047] S1023: Separate the zirconia balls from the dried product through a sieve to obtain the first product.

[0048] Specifically, the barium titanate-based ceramic powder, zirconia balls, and anhydrous ethanol are mixed in a mass ratio of 1:2:1 to obtain a mixed product. The mixed product is ball-milled for 4 hours. After mixing and grinding, it is rapidly dried at 100-130°C to obtain a dried product. The dried product is then passed through a sieve to separate the zirconia balls, thus obtaining the first product.

[0049] S103: The first product is mixed and separated to obtain powder, and the powder is pressed with a mold to obtain a disc;

[0050] S1031: Polyvinyl alcohol is added to the first product for granulation to obtain a first product with fine particle size;

[0051] S1033: The fine-particle-size first product is pressed through a mold to obtain a disc.

[0052] Specifically, the fine-grained barium titanate-based ceramic powder after granulation is pressed into discs with a diameter of 8 mm and a thickness of 1.2 mm, and the binder is removed at 550℃ for 4 hours, with a heating rate of 1℃ / min.

[0053] S104: The disc is sintered to obtain a barium titanate-based ceramic material with high energy storage density.

[0054] Specifically, the sintering conditions are a temperature of 1200-1300℃ and a holding time of 2 hours.

[0055] By introducing the strong ferroelectric Bi(Mg) 1 / 4 Zn 1 / 4 Ti 1 / 2 )O3 and (Bi 0.5 Na 0.5 TiO3 and BaTiO3 antiferroelectrics form a uniform solid solution to improve the maximum polarization intensity and breakdown field strength of ceramic materials, thereby increasing the energy storage density of dielectric ceramic materials and solving the problem of low energy storage density of existing dielectric ceramic materials.

[0056] The second embodiment of this application is as follows:

[0057] Based on the first embodiment, this embodiment provides a high energy density barium titanate-based ceramic material, prepared using the aforementioned method for preparing a high energy density barium titanate-based ceramic material, comprising BaCO3, TiO2, Bi2O3, MgO, ZnO, and Na2CO3. Specific Implementation Example 1:

[0059] High-purity powders of BaCO3, TiO2, Bi2O3, MgO, ZnO, and Na2CO3 with a purity ≥99% were prepared as raw materials. BaCO3 and TiO2 were weighed according to stoichiometric ratios and mixed, then pre-fired and held at a certain temperature to obtain a 0.9 mol% BaTiO3 main crystalline phase. Bi2O3, MgO, ZnO, and TiO2 were weighed according to stoichiometric ratios and mixed, then pre-fired and held at a certain temperature to obtain a 0.1 mol% Bi(MgO)2O3 main crystalline phase. 1 / 4 Zn 1 / 4 Ti 1 / 2 The main crystalline phase is Bi₂O₃; Bi₂O₃, Na₂CO₃, and TiO₂ are weighed according to stoichiometric ratio, mixed, pre-calcined and kept at a certain temperature to obtain a 0 molar percentage (Bi₂O₃)₂O₃. 0.5 Na 0.5 )0TiO3 main crystal phase; weigh BaTiO3 and Bi(Mg) according to stoichiometric ratio 1 / 4Zn 1 / 4 Ti 1 / 2 The mixture was prepared by mixing O3 and pre-calcining at a certain temperature to obtain 0.9BaTiO3-0.1Bi(Mg) 1 / 4 Zn 1 / 4 Ti 1 / 2 O3 is the main crystalline phase; 0.9BaTiO3-0.1Bi(Mg)3-10.5g of stoichiometric ratio will be used. 1 / 4 Zn 1 / 4 Ti 1 / 2 O3, 0 molar percentage (Bi) 0.5 Na 0.5 By mixing TiO3 and pre-calcining and holding at a certain temperature, 0.9BaTiO3-0.1Bi(Mg) can be obtained. 1 / 4 Zn 1 / 4 Ti 1 / 2 Zirconia powder, zirconium oxide balls, and anhydrous ethanol were added sequentially to the powder in a mass ratio of 1:2:1. The mixture was ball-milled for 4 hours, and after fine grinding, it was rapidly dried at 100-130℃. The zirconium oxide balls were separated using a sieve, and the sieved powder was pre-fired in an alumina crucible at 850℃ for 4 hours at a heating rate of 5℃ / min. The pre-fired powder was then ball-milled again in a nylon can in the same 1:2:1 mass ratio for 4 hours. Afterward, it was removed and dried in an oven at 100-130℃. The dried powder was then granulated with 8wt% polyvinyl alcohol, and pressed into small cylinders with a diameter of 8mm and a thickness of 1.2mm. These cylinders were then debinded at 550℃ for 4 hours at a heating rate of 1℃ / min. Finally, the small cylinders after the adhesive has been removed are sintered at 1100-1300℃ for 2 hours to obtain the desired ceramic material. Specific Implementation Example 2:

[0061] The prepared barium titanate-based ceramic powder has the following composition: (0.95)[0.9BaTiO3-0.1Bi(Mg)] 1 / 4 Zn 1 / 4Ti 1 / 2 [O3]-0.05mol% (Bi 0.5 Na 0.5 Weigh the high-purity TiO3 powders, and follow the same steps as in Specific Example 1. Specific Implementation Example 3:

[0063] The prepared barium titanate-based ceramic powder has the following composition: (0.9)[0.9BaTiO3-0.1Bi(Mg)] 1 / 4 Zn 1 / 4Ti 1 / 2 )O3]-0.1mol%(Bi 0.5 Na 0.5 Weigh the high-purity TiO3 powders, and follow the same steps as in Specific Example 1. Specific Implementation Example 4:

[0065] The prepared barium titanate-based ceramic powder has the following composition: (0.85)[0.9BaTiO3-0.1Bi(Mg)]. 1 / 4 Zn 1 / 4Ti 1 / 2 [O3]-0.15mol% (Bi 0.5 Na 0.5 Weigh the high-purity TiO3 powders, and follow the same steps as in Specific Example 1. Specific Implementation Example 5:

[0067] The prepared barium titanate-based ceramic powder has the following composition: (0.8)[0.9BaTiO3-0.1Bi(Mg)] 1 / 4 Zn 1 / 4Ti 1 / 2 )O3]-0.2mol%(Bi 0.5 Na 0.5 Weigh the high-purity TiO3 powders, and follow the same steps as in Specific Example 1.

[0068] The energy storage performance of the barium titanate-based ceramic powders prepared in specific embodiments 1 to 5 is compared in the following table:

[0069]

[0070] The comparison results show that the ceramic has a high energy storage density (3.76 J / cm³) when x = 0.10. 3With a high energy storage efficiency (88.1%), it can be considered a preferred composition. Furthermore, it maintains a relatively stable energy storage density within a temperature range of 25-200℃. Therefore, (1-x)[0.9BaTiO3-0.1Bi(Mg)]... 1 / 4 Zn 1 / 4 Ti 1 / 2 [O3]-xmol%(Bi 0.5 Na 0.5 TiO3 shows promise as a high-energy-storage pulse power capacitor.

[0071] This invention significantly improves the breakdown strength and insulation properties of BaTiO3 by introducing high-insulation-performance MgO, ZnO, and Bi(MgO). 1 / 4 Zn 1 / 4 Ti 1 / 2 The introduction of Bi(MgO)3 can promote the sintering of BaTiO3 ceramics, significantly reduce their porosity and grain size, and thus obtain high breakdown strength. 1 / 4 Zn 1 / 4 Ti 1 / 2 )O3 and (Bi 0.5 Na 0.5 TiO3 transforms ferroelectric domains into polar nanodomains, and by utilizing the rapid response of polar nanodomains under an applied electric field, the energy storage density and energy storage efficiency of the material are significantly improved.

[0072] The beneficial effects of this invention are: by introducing the strong ferroelectric material Bi(Mg) 1 / 4 Zn 1 / 4 Ti 1 / 2 )O3 and (Bi 0.5 Na 0.5 TiO3 and BaTiO3 antiferroelectrics form a uniform solid solution to improve the maximum polarization intensity and breakdown field strength of ceramic materials, thereby increasing the energy storage density of dielectric ceramic materials.

[0073] The above-disclosed embodiments are merely one or more preferred embodiments of this application and should not be construed as limiting the scope of this application. Those skilled in the art can understand that all or part of the processes for implementing the above embodiments and equivalent changes made in accordance with the claims of this application still fall within the scope of this application.

Claims

1. A method for preparing a barium titanate-based ceramic material with high energy storage density, characterized in that, Includes the following steps: Barium titanate-based ceramic powder is obtained by pre-firing and holding the raw materials at a certain temperature. The raw materials are BaCO3, TiO2, Bi2O3, MgO, ZnO, and Na2CO3. This includes mixing BaCO3 and TiO2 and pre-firing and holding the mixture to obtain the BaTiO3 main crystalline phase; and mixing Bi2O3, MgO, ZnO, and TiO2 and pre-firing and holding the mixture to obtain Bi(MgO)2O3. 1 / 4 Zn 1 / 4 Ti 1 / 2 The main crystalline phase is O3; Bi2O3, Na2CO3, and TiO2 are mixed and pre-calcined at a certain temperature to obtain (Bi2O3)3. 0.5 Na 0.5 The main crystal phase of TiO3; the main crystal phase of BaTiO3 and the main crystal phase of Bi(Mg) 1 / 4 Zn 1 / 4 Ti 1 / 2 The O3 main crystalline phase was mixed and pre-fired at a certain temperature to obtain 0.9BaTiO3-0.1Bi(Mg) 1 / 4 Zn 1 / 4 Ti 1 / 2 O3 main crystal phase; the 0.9BaTiO3-0.1Bi(Mg) group is used as the main crystal phase. 1 / 4 Zn 1 / 4 Ti 1 / 2 O3 main crystal phase and the (Bi) 0.5 Na 0.5 The TiO3 main crystalline phase is mixed and pre-fired and kept at a certain temperature to obtain barium titanate-based ceramic powder. The pre-fired temperature is 720-850℃ and the holding time is 4-6h. The barium titanate-based ceramic powder is pretreated and then pressed and pre-fired to obtain a first product. This process includes mixing the barium titanate-based ceramic powder, zirconia balls, and anhydrous ethanol at a mass ratio of 1:2:1 to obtain a mixed product; ball milling the mixed product for 4 hours and then rapidly drying it at 100-130°C to obtain a dried product; and separating the zirconia balls from the dried product using a sieve to obtain the first product. The first product is mixed and separated to obtain powder, and the powder is pressed into discs using a mold. The mixture includes adding polyvinyl alcohol to the first product for granulation to obtain a fine-particle-size first product. The fine-particle-size first product is pressed into discs with a diameter of 8 mm and a thickness of 1.2 mm using a mold, and the glue is removed at 550°C for 4 hours with a heating rate of 1°C / min. The discs are sintered to obtain a barium titanate-based ceramic material with high energy storage density. The sintering conditions are a temperature of 1200-1300℃ and a holding time of 2h.

2. A high-energy-density barium titanate-based ceramic material, applied to the preparation method of the high-energy-density barium titanate-based ceramic material as described in claim 1, characterized in that, The high energy density barium titanate-based ceramic materials include BaCO3, TiO2, Bi2O3, MgO, ZnO, and Na2CO3.

Images