A polybasic sodium bismuth titanate-based environmentally friendly ceramic with excellent comprehensive energy storage properties and a preparation method thereof

Abstract

The invention relates to the technical field of ceramic materials, and discloses a polybasic sodium bismuth titanate-based environmentally friendly ceramic with excellent comprehensive energy storage properties. The nominal chemical formula of the material is (100‑x‑y) mol% Na 0.5 Bi 0.5 TiO3‑xmol%BaTiO3‑ymol%Sr 0.8 Ca 0.2 Ti 0.9 Al 0.05 Ta 0.05 O3-zmol%La2O3, 6.5<x<9.5, 28<y<31, 0.5<z<1. In addition, the preparation process of the present invention is novel and relatively low in cost and environmentally friendly. The obtained ceramic capacitor material has excellent energy storage and charge-discharge characteristics, strong thermal stability, and good industrialization prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of ceramic materials, and in particular to a polynary sodium bismuth titanate-based environmentally friendly ceramic with excellent comprehensive energy storage characteristics and a preparation method thereof. Background Art

[0002] In recent years, dielectric energy storage capacitors have attracted more and more attention due to their high power density and extremely fast charge and discharge speed. Compared with batteries and supercapacitors, they have shown great advantages in pulse power system applications. Among the many dielectric energy storage capacitor materials, ceramic-based dielectric energy storage capacitors have received widespread attention due to their relatively high dielectric constant, moderate breakdown field strength, excellent thermal stability, superior mechanical strength and low cost.

[0003] In the past decade or so of research on energy storage ceramic capacitors, researchers have discovered a series of environmentally friendly dielectric ceramic materials, such as barium titanate, potassium sodium niobate, silver niobate, sodium bismuth titanate, etc. Among them, multi-sodium bismuth titanate-based relaxor ferroelectric ceramics exhibit excellent energy storage performance due to their large saturation polarization intensity and small residual polarization intensity, as well as moderate breakdown electric field strength. Therefore, obtaining lead-free sodium bismuth titanate-based ceramics with high energy storage characteristics through doping modification and optimization of preparation conditions has become a research hotspot in the current technical direction of energy storage materials. Based on this, the present invention provides a multi-sodium bismuth titanate-based environmentally friendly ceramic with excellent comprehensive energy storage characteristics and a preparation method thereof. Summary of the invention

[0004] The present invention provides a polybasic sodium bismuth titanate-based environmentally friendly ceramic with excellent comprehensive energy storage characteristics and a preparation method thereof, which solves the problems raised in the above-mentioned background technology.

[0005] The present invention provides the following technical solution: a polybasic sodium bismuth titanate-based environmentally friendly ceramic with excellent comprehensive energy storage properties, the nominal chemical formula of the material is (100-xy) mol% Na 0.5 Bi 0.5 TiO3-xmol%BaTiO3-ymol%Sr 0.8 Ca 0.2 Ti 0.9 Al 0.05 Ta 0.05 O3-zmol%La2O3.

[0006] A method for preparing a polybasic sodium bismuth titanate-based environmentally friendly ceramic with excellent comprehensive energy storage properties, the specific steps are as follows:

[0007] (1) Anhydrous sodium carbonate, bismuth trioxide, titanium dioxide, barium carbonate, strontium carbonate, calcium carbonate, aluminum trioxide, tantalum pentoxide and lanthanum trioxide were used as starting materials.0.5 Bi 0.5 TiO3:BaTiO3:Sr 0.8 Ca 0.2 Ti 0.9 Al 0.05 Ta 0.05 The ingredients are prepared in a molar ratio of O3:La2O3=(0.58-0.655):(0.06-0.1):(0.28-0.31):(0.005-0.01), and anhydrous ethanol is used as a ball milling medium. The mixture is evenly mixed and then dried.

[0008] (2) crushing the pre-calcined powder obtained in step (1), then mixing it evenly with anhydrous ethanol as a ball milling medium, drying it, and grinding it into a micron-sized powder;

[0009] (3) adding the powder prepared in step (2) to a PVA binder, wherein the mass ratio of the powder prepared in step (2) to the PVA binder is 95:5, and then granulating, tabletting, and debinding to obtain a ceramic embryo body;

[0010] (4) The ceramic body prepared in step (3) is subjected to an electric field strength of 28-38 V / mm and a current strength of 2.5-3.5 A / cm 2 The flash sintering treatment is carried out under the conditions and the sintering is carried out at a temperature of 650-750° C. for 100-400s to obtain a polybasic sodium bismuth titanate-based lead-free ceramic material.

[0011] Optionally, the purity of all starting raw material powders in step (1) is 99.99%.

[0012] Optionally, in step (1), the ball milling time is 16-18 h, the drying temperature is 100-110° C., and the drying time is 17-19 h.

[0013] Optionally, in step (3), the diameter of the tableting mold is 6-8 mm, the pressure is 90-120 MPa, and the holding time is 3-6 minutes.

[0014] Optionally, in step (3), the debinding temperature is 520-560° C., and the debinding time is 2-3.5 h.

[0015] Optionally, the electric field intensity of the flash burning in step (4) is 280-380 V / cm, and the current intensity is 2.5-3.5 A / cm 2 .

[0016] Optionally, the flash firing temperature in step (4) is 650-750° C., and the holding time is 100-400 s.

[0017] The present invention has the following beneficial effects:

[0018] The preparation process of the invention is novel and reliable, and the cost is relatively low and environmentally friendly. The obtained ceramic capacitor material has excellent energy storage and charge-discharge characteristics, and has strong thermal stability and good industrialization prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 62mol%Na prepared in the embodiment of the present invention 0.5 Bi 0.5 TiO3-8mol%BaTiO3-29mol%Sr 0.8 Ca 0.2 Ti 0.9 Al 0.05 Ta 0.05 X-ray spectrum of O3-1mol%La2O3 multi-component sodium bismuth titanate-based lead-free ceramic material with high energy storage properties;

[0020] Figure 2 62mol%Na prepared in the embodiment of the present invention 0.5 Bi 0.5 TiO3-8mol%BaTiO3-29mol%Sr 0.8 Ca 0.2 Ti 0.9 Al 0.05 Ta 0.05 Microscopic morphology of O3-1mol%La2O3 multi-component sodium bismuth titanate-based lead-free ceramic material with high energy storage properties;

[0021] Figure 3 62mol%Na prepared in the embodiment of the present invention 0.5 Bi 0.5 TiO3-8mol%BaTiO3-29mol%Sr 0.8 Ca 0.2 Ti 0.9 Al 0.05 Ta 0.05 Weibull distribution fitting diagram of the breakdown electric field strength of O3-1mol%La2O3 multi-component sodium bismuth titanate-based lead-free ceramic material with high energy storage characteristics;

[0022] Figure 4 62mol%Na prepared in the embodiment of the present invention 0.5 Bi 0.5 TiO3-8mol%BaTiO3-29mol%Sr 0.8 Ca 0.2 Ti 0.9 Al 0.05 Ta 0.05 Hysteresis loop diagram of O3-1mol%La2O3 multi-component sodium bismuth titanate-based lead-free ceramic material with high energy storage properties;

[0023] Figure 5 62mol%Na prepared in the embodiment of the present invention 0.5 Bi 0.5 TiO3-8mol%BaTiO3-29mol%Sr 0.8 Ca 0.2 Ti 0.9 Al 0.05 Ta 0.05 Hysteresis loop diagram of temperature-variable test of lead-free ceramic material with high energy storage characteristics based on multi-component bismuth sodium titanate O3-1mol%La2O3;

[0024] Figure 6 62mol%Na prepared in the embodiment of the present invention 0.5 Bi 0.5 TiO3-8mol%BaTiO3-29mol%Sr 0.8 Ca 0.2 Ti 0.9 Al 0.05 Ta 0.05 The current curves of the O3-1mol% La2O3 multi-component sodium bismuth titanate-based lead-free ceramic material with high energy storage properties tested at different electric field intensities at room temperature in the underdamped state;

[0025] Figure 7 62mol%Na prepared in the present invention 0.5 Bi 0.5 TiO3-8mol%BaTiO3-29mol%Sr 0.8 Ca 0.2 Ti 0.9 Al 0.05 Ta 0.05 Current curves of O3-1mol%La2O3 multi-component bismuth sodium titanate-based lead-free ceramic material with high energy storage properties tested at different electric field intensities at room temperature in the over-damped state. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] The present invention provides a multi-element sodium bismuth titanate-based environmentally friendly ceramic capacitor with excellent comprehensive energy storage characteristics and a preparation method thereof, and the specific steps are as follows:

[0028] (1) Anhydrous sodium carbonate with a purity of 99.99%, bismuth trioxide, titanium dioxide, barium carbonate, strontium carbonate, calcium carbonate, aluminum trioxide, tantalum pentoxide and lanthanum trioxide raw materials were mixed in a stoichiometric ratio of 62 mol% Na 0.5 Bi 0.5 TiO3-8mol%BaTiO3-29mol%Sr 0.8 Ca 0.2 Ti 0.9 Al 0.05 Ta 0.05 O3-1mol% La2O3 ingredients are placed in a nylon ball mill, zirconium dioxide balls and anhydrous ethanol are selected as ball milling media, the mixed ball milling time is 16-18 hours, the speed is (350-380) rpm. The ball milled product is placed in a 100-110°C oven and dried for 17-19 hours.

[0029] (2) Take out the dried powder and grind it thoroughly. Add 5-10g of the powder into 4-10mL of PVA solution (PVA6-8wt%) and grind it thoroughly. Take 0.3-0.4g of the fully ground powder and place it in a mold with a diameter of 6-10mm. Maintain the pressure at 90-120MPa for 3-6 minutes. After pressing, the green body is at 520-560℃ and the debinding time is 2-3.5h.

[0030] (3) The ceramic body obtained after debinding is subjected to an electric field strength of 280-380 V / cm and a current strength of 2.5-3.5 A / cm 2 The flash sintering treatment is carried out under the conditions, and the corresponding ceramic block material is obtained by sintering at 650-750°C for 100-400s.

[0031] The phase structure and microstructure of the polybasic sodium bismuth titanate-based environmentally friendly ceramic material prepared in Example 1 were characterized. Figure 1 Attached Figure 2 As shown in the figure, it can be seen that the ceramic material obtained by the above preparation method exists in a single-phase perovskite structure and has a microstructure with fine and uniform grains. In addition, by performing multiple electrical breakdown tests on it and determining its reliable breakdown field strength value (such as 50kV / mm) using Weibull distribution, as shown in the attached figure Figure 3 According to the experimental results obtained above, the PE curve was tested under this electric field strength, as shown in the attached Figure 4 As shown in Figure 2, the effective energy storage density of this multi-element sodium bismuth titanate-based environmentally friendly ceramic material can reach a relatively high value of 8.35 J / cm at an electric field strength of 50 kV / mm. 3, and maintain a relatively high energy storage efficiency value, such as 93%. In addition, within the temperature range of 20℃~140℃, the sample also has excellent energy storage stability, such as the attached Figure 5 In addition, the sample also has a high power density, such as 62MW / cm 3 , and faster charge and discharge speed, such as 270ns, as shown in the attached Figure 6 And attached Figure 7 As shown. It meets the practical application requirements of ceramic energy storage capacitors and is expected to be used in the electronic ceramics market.

[0032] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a polybasic sodium bismuth titanate-based environmentally friendly ceramic with excellent comprehensive energy storage properties, characterized in that: The specific steps are as follows: (1) Anhydrous sodium carbonate, bismuth trioxide, titanium dioxide, barium carbonate, strontium carbonate, calcium carbonate, aluminum trioxide, tantalum pentoxide and lanthanum trioxide were used as starting materials. 0.5 Bi 0.5 TiO3:BaTiO3:Sr 0.8 Ca 0.2 Ti 0.9 Al 0.05 Ta 0.05 The ingredients are prepared in a molar ratio of O3:La2O3=(0.58~0.655):(0.06~0.1):(0.28~0.31):(0.005~0.01), and anhydrous ethanol is used as the ball milling medium. The mixture is evenly mixed and then dried. (2) crushing the pre-calcined powder obtained in step (1), and then ball milling with anhydrous ethanol as a ball milling medium to mix evenly, drying, and grinding into micron-sized powder; (3) adding the powder prepared in step (2) to a PVA binder, wherein the mass ratio of the powder prepared in step (2) to the PVA binder is 95:5, and then granulating, tabletting, and debinding to obtain a ceramic body; (4) The ceramic body prepared in step (3) is placed in an electric field with an intensity of 28-38 V / mm and a current intensity of 2.5-3.5 A / cm 2 The flash sintering treatment is carried out under the conditions of 650-750°C for 100-400 s to obtain the polybasic sodium bismuth titanate-based lead-free ceramic material.

2. The method for preparing the polybasic sodium bismuth titanate-based environmentally friendly ceramic with excellent comprehensive energy storage characteristics according to claim 1, characterized in that: The purity of all starting raw material powders in step (1) is 99.99%.

3. The method for preparing the polybasic sodium bismuth titanate-based environmentally friendly ceramic with excellent comprehensive energy storage characteristics according to claim 1, characterized in that: In step (1), the ball milling time is 16-18 hours, the drying temperature is 100-110° C., and the drying time is 17-19 hours.

4. The method for preparing the polybasic sodium bismuth titanate-based environmentally friendly ceramic with excellent comprehensive energy storage characteristics according to claim 1, characterized in that: In step (3), the diameter of the tablet pressing mold is 6-8 mm, the pressure is 90-120 MPa, and the holding time is 3-6 minutes.

5. The method for preparing the polybasic sodium bismuth titanate-based environmentally friendly ceramic with excellent comprehensive energy storage characteristics according to claim 1, characterized in that: In step (3), the debinding temperature is 520-560°C and the debinding time is 2-3.5h.

6. The method for preparing the polybasic sodium bismuth titanate-based environmentally friendly ceramic with excellent comprehensive energy storage characteristics according to claim 1, characterized in that: The electric field intensity of the flash burning in step (4) is 280-380 V / cm and the current intensity is 2.5-3.5 A / cm 2 .

7. The method for preparing the polybasic sodium bismuth titanate-based environmentally friendly ceramic with excellent comprehensive energy storage characteristics according to claim 1, characterized in that: The flash firing temperature in step (4) is 650-750°C, and the holding time is 100-400s.

8. A polybasic sodium bismuth titanate-based environmentally friendly ceramic with excellent comprehensive energy storage properties prepared according to the method of any one of claims 1 to 7, characterized in that: The nominal chemical formula of this material is (100- xy ) mol% Na 0.5 Bi 0.5 TiO3- x mol% BaTiO3- y mol% Sr 0.8 Ca 0.2 Ti 0.9 Al 0.05 Ta 0.05 O3- z mol% La2O3.

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