CN116639971A - Strontium zirconate doped copper sodium calcium cadmium titanate ceramic with high energy storage density and preparation method thereof - Google Patents

Abstract

The application belongs to the technical field of energy storage materials, and discloses strontium zirconate doped copper sodium calcium cadmium titanate ceramic with high energy storage density and a preparation method thereof. The chemical general formula of the ceramic is Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ ‑xSrZrO ₃ Wherein x is SrZrO ₃ Take up Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ 0 mass percent of (C)<x is less than or equal to 0.1. The method synthesizes the high dielectric constant material of copper sodium calcium cadmium titanate, adopts strontium zirconate doping to obtain Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ ‑xSrZrO ₃ A ceramic; inhibiting abnormal growth of copper sodium calcium cadmium titanate crystal grains by utilizing strontium and zirconium ions, and enhancingThe insulation property of grain boundary and the density of material improve the breakdown field strength, and simultaneously have high dielectric constant and breakdown field strength, and the energy storage density can reach 1.15-2.23J/cm ³ 。

Description

A high energy storage density strontium zirconate doped copper sodium calcium cadmium titanate ceramic and its preparation method

technical field

The invention belongs to the technical field of energy storage materials, in particular to a strontium zirconate doped copper sodium calcium cadmium titanate ceramic with high energy storage density and a preparation method thereof.

Background technique

The development of information technology has put forward requirements for the miniaturization and intelligence of electronic components, and dielectric materials with high dielectric constant and energy storage density are the key to solving this problem. In recent years, researchers have reported a series of high dielectric constant ceramic materials, and the small breakdown field strength of these materials often leads to low energy storage density. Copper calcium titanate (CaCu ₃ Ti ₄ O ₁₂ , CCTO) non-ferroelectric dielectric ceramic material is a member of the ACTO family. Its dielectric constant is as high as 10 ⁴ , and it has good temperature stability at 100-600K and no Structural phase transitions are expected to be widely used in high-density energy storage and high-dielectric capacitors.

The energy storage density of ACTO dielectrics can be expressed as: Among them, ε ₀ , ε _r , and E _b are the dielectric constant, relative dielectric constant, and breakdown strength in vacuum, respectively. It can be seen from the above formula that its energy density is proportional to the dielectric constant and breakdown strength; in order to maximize the charge that the capacitor can hold, the dielectric material needs to have a high dielectric constant and breakdown field strength. However, studies have shown that the dielectric constant and breakdown strength of a single material can only be enhanced at the expense of each other. Therefore, designing and developing dielectric materials with both high dielectric constant and high breakdown field strength is an effective way to achieve high energy storage density of dielectric materials. In 2020, Yang Zupei and others from Shaanxi Normal University improved the breakdown field strength of ceramics by adding alumina to CdCu ₃ Ti ₄ O ₁₂ , and the best energy storage density was 1.52mJ/cm ³ (Z.Peng, J .Wang, X.Zhou, J.Zhu, X.Lei, P.Liang, X.Chao, Z.Yang, Grain engineering inducing high energy storage in CdCu ₃ Ti ₄ O ₁₂ ceramics, Ceramics International 46(2020) 14425-14430 ); in 2022, they increased the breakdown field strength of ceramic materials by adding silicon dioxide to CdCu ₃ Ti ₄ O ₁₂ , and the maximum energy storage density reached 1.77mJ/cm ³ (Z.Peng, J.Wang, F. Zhang,S.Xu,X.Lei,P.Liang,L.Wei,D.Wu,X.Chao,Z.Yang,High energy storage and colossal permittivity CdCu ₃ Ti ₄ O ₁₂ oxide ceramics,Ceramics International 48(2022)4255 -4260). These results demonstrate the usefulness and potential application of conducting such research.

At present, researchers are still exploring new high dielectric constant ceramic materials, and the low breakdown field strength of such materials has become a key problem hindering the improvement of their energy storage density. Therefore, it is necessary to develop high dielectric constant At the same time as ceramic materials, their breakdown field strength is increased, so as to achieve the purpose of improving their energy storage density.

Contents of the invention

The object of the present invention is to provide a strontium zirconate doped copper sodium calcium cadmium titanate ceramic with high energy storage density and its preparation in view of the problem that the low breakdown field strength in the prior art hinders the improvement of its energy storage density method, a high dielectric constant copper sodium calcium cadmium titanate (Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ , NCCCTO) ceramic material with mixed Ⅰ/Ⅱ/Ⅱ valence occupying the Ca site was synthesized, and then doped with the second phase Strontium zirconate (SrZrO ₃ ) improves the breakdown field strength of ceramics, and finally prepares a strontium zirconate doped copper sodium calcium cadmium titanate ceramic material with high energy storage density. This method improves the breakdown field strength of ceramics. At the same time, it maintains its high dielectric constant, the dielectric constant at 1kHz is 6100-8300, the breakdown field strength is 56-82kV/cm, and the energy storage density is 1.15-2.23J/cm ³ , thus realizing the energy storage density significantly improved.

In order to achieve the above object, the technical solution adopted by the application is:

The first object of the present invention is to provide a high energy storage density strontium zirconate doped copper sodium calcium cadmium titanate ceramic, the general chemical formula of the ceramic is Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ - xSrZrO ₃ , where x is the mass percentage of SrZrO ₃ in Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ , 0<x≤0.1.

Preferably, where 0.02≤x≤0.08.

The second object of the present invention is to provide a method for preparing the above-mentioned strontium zirconate doped copper sodium calcium cadmium titanate ceramics with high energy storage density, comprising the following steps:

S1. Select Na ₂ CO ₃ , CaCO ₃ , CdO, CuO, TiO ₂ , SrCO ₃ and ZrO ₂ as raw material powders, mix ingredients according to the general formula Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ and SrZrO ₃ , and grind Finally, powders A and B that are uniformly mixed are obtained respectively;

S2. Sinter powder A to obtain Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ powder C; sinter powder B to obtain SrZrO ₃ powder D; powder C and powder D according to the general chemical formula Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ -xSrZrO ₃ is mixed in proportion, after grinding, adding a binder and granulating, pressing and molding to obtain a ceramic green body;

S3. Debinding the ceramic body first, then heating up and keeping warm to obtain strontium zirconate doped copper sodium calcium cadmium titanate ceramics.

Preferably, in S1, the grinding method is ball milling for 12-24 hours.

Preferably, in S2, the sintering temperature of the powder A is 850-950° C., the holding time is 6-8 hours, and the heating rate is 2-3° C./min.

Preferably, in S2, the sintering temperature of the powder B is 1100-1200° C., the holding time is 3-4 hours, and the heating rate is 3-4° C./min.

Preferably, in S2, the binder is polyvinyl alcohol, and the amount of polyvinyl alcohol added is 3-4 wt% of the powder mass after grinding.

Preferably, in S2, the pressure of the press forming is 200-250 MPa; the size of the ceramic green body is 1 cm in diameter and 0.7-0.8 mm in thickness.

Preferably, in S3, the degumming temperature is 580-620°C, the holding time is 2-3 hours, the heating rate is 2-3°C/min, the temperature rises to 1150°C, and the holding time is 6-3 hours. 8h, the heating rate is 3-5°C/min.

Compared with prior art, the beneficial effect of the present invention:

(1) The present invention synthesized a new high dielectric constant ceramic material copper sodium calcium cadmium titanate (Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ ), by doping strontium zirconate (SrZrO ₃ ), using Strontium and zirconium ions inhibit the abnormal growth of copper sodium calcium cadmium titanate grains, enhance the insulation of grain boundaries and the density of materials, and significantly increase the breakdown field strength, and finally achieve strontium zirconate doped copper sodium calcium titanate Cadmium (Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ -xSrZrO ₃ ) ceramics, which have high dielectric constant and breakdown field strength, and the energy storage density can reach 1.15-2.23J/cm ³ .

(2) The preparation method of the ceramic material of the present invention is simple, low in cost, good in repeatability, and is suitable for industrial production. When x=0.05, the breakdown field strength of the ceramic is 82kV/cm, and the dielectric constant at 1kHz It is 7500, and the energy storage density is 2.23J/cm ³ , which has very important application value in high-density energy storage, high dielectric capacitor and other fields.

Description of drawings

Fig. 1 is the XRD figure of the strontium zirconate doped copper sodium calcium cadmium titanate ceramics prepared by the present invention and Examples 1-5 and Comparative Example 1;

Fig. 2 is the Raman spectrogram of strontium zirconate-doped copper sodium calcium cadmium titanate ceramics prepared by Examples 1-5 of the present invention and Comparative Example 1;

Fig. 3 is the variation of the dielectric constant of the strontium zirconate-doped copper sodium calcium cadmium titanate ceramics as a function of frequency prepared by Examples 1-5 of the present invention and Comparative Example 1;

Fig. 4 is a graph showing the variation of nonlinear coefficient, breakdown field strength and energy storage density of strontium zirconate-doped copper sodium calcium cadmium titanate ceramics prepared in Examples 1-5 and Comparative Example 1 of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the data in the embodiments of the present invention. Apparently, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

It should be noted that the technical terms used in the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the protection scope of the present invention. Unless otherwise specified, each of the terms used in the following embodiments of the present invention All raw materials, reagents, instruments and equipment can be purchased from the market or prepared by existing methods.

A strontium zirconate doped copper sodium titanate calcium cadmium ceramic with high energy storage density, the general chemical formula of the ceramic is Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ -xSrZrO ₃ , where 0<x≤ 0.1, preferably, 0.02≤x≤0.08.

By adding strontium zirconate, strontium and zirconium ions are used to suppress the abnormal growth of copper sodium calcium cadmium titanate grains, enhance the insulation of grain boundaries and the density of materials, significantly improve the breakdown field strength, and finally achieve strontium zirconate Doped copper sodium calcium cadmium titanate ceramics have high dielectric constant and breakdown field strength at the same time to achieve the purpose of improving its energy storage density. The ceramic material has a dielectric constant of 6100-8300 at 1kHz and a The field strength is 56-82kV/cm, and the energy storage density is 1.15-2.23J/cm ³ .

The above-mentioned high energy storage density strontium zirconate doped copper sodium calcium cadmium titanate ceramics preparation method comprises the following steps:

S1. Select Na ₂ CO ₃ , CaCO ₃ , CdO, CuO, TiO ₂ , SrCO ₃ and ZrO ₂ as raw material powders, and mix ingredients according to the general formula Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ and SrZrO ₃ , fully After ball milling for 12-24 hours, uniformly mixed powders A and B were obtained respectively;

S2. Raise the temperature of powder A to 850-950°C at 2-3°C/min, and sinter in air atmosphere for 6-8h to obtain Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ powder C; 3～4℃/min to raise the temperature to 1100～1200℃, and sinter in air atmosphere for 3～4 hours to obtain SrZrO ₃ powder D; powder C and powder D according to the general chemical formula Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ -xSrZrO ₃ is mixed in proportion, after grinding, 3-4wt% polyvinyl alcohol is added to the powder mass and granulated, and pressed at 200-250MPa to form a ceramic green body with a diameter of 1cm and a thickness of 0.7-0.8mm;

S3. Heat the ceramic body at 2-3°C/min to 580-620°C, heat it for 2-3 hours and discharge glue, then heat it up to 1150°C at 3-5°C/min, hold it for 6-8 hours, and cool it with the furnace to obtain A strontium zirconate doped copper sodium calcium cadmium titanate ceramic is obtained.

Examples are given below to describe the present invention in detail.

Example 1

A high energy storage density strontium zirconate doped copper sodium calcium cadmium titanate ceramic, the composition of the ceramic is Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ -0.05SrZrO ₃ .

The above-mentioned high energy storage density strontium zirconate doped copper sodium calcium cadmium titanate ceramics preparation method comprises the following steps:

S1. According to the general composition formula Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ , weigh 0.31797gNa ₂ CO ₃ , 0.40036gCaCO ₃ , 1.2841gCdO, 4.773gCuO, 5.1096gTiO ₂ and place them in the ball mill jar, then place the ball mill jar After fully grinding in a ball mill for 16 hours, powder A was obtained; according to the general composition formula SrZrO ₃ , 1.4763g SrCO ₃ and 1.2322g ZrO ₂ were weighed and placed in a ball mill jar, and then the ball mill jar was placed in a ball mill and fully ground for 16 hours to obtain powder B;

S2. Raise the temperature of powder A to 900°C at 3°C/min, and sinter in air atmosphere for 7h to obtain Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ powder C; raise the temperature of powder B to 900°C at 4°C/min Sinter at 1150°C for 4 hours in an air atmosphere to obtain SrZrO ₃ powder D; add powder D to powder C according to the mass percentage of the chemical formula Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ -0.05SrZrO ₃ , and grind thoroughly After 18 hours, add polyvinyl alcohol binder with 3wt% powder mass, granulate, and press under 220MPa to form a ceramic green body with a diameter of 1cm and a thickness of 0.8mm;

S3. Heat up the ceramic body at 2°C/min to 600°C, heat it for 3 hours and discharge glue, then heat it up to 1150°C at 5°C/min, hold it for 8 hours, and cool it with the furnace to get Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ -0.05SrZrO ₃ ceramics.

The sintered ceramic sample was polished to 200 μm with sandpaper, and the upper and lower surfaces of the ceramic were brushed with silver paste for electrical performance testing. The dielectric constant of the obtained ceramic material was 7500 at 1 kHz, the breakdown field strength was 82 kV/cm, and the energy density was 2.23 J/cm ³ .

Example 2

A high energy storage density strontium zirconate doped copper sodium calcium cadmium titanate ceramic, the composition of the ceramic is Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ -0.02SrZrO ₃ .

The preparation method is the same as in Example 1, the difference is that: according to the composition formula Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ , weigh _{0.31797gNa2CO3} , _{0.40036gCaCO3 ,} 1.2841gCdO, 4.773gCuO, _5.1096gTiO2 ; according to the composition The general formula SrZrO ₃ weighs 0.59025g SrCO ₃ and 0.49288g ZrO ₂ .

The sintered ceramic sample was polished to 200 μm with sandpaper, and the upper and lower surfaces of the ceramic were brushed with silver paste for electrical performance testing. The dielectric constant of the obtained ceramic material was 8300 at 1 kHz, the breakdown field strength was 56 kV/cm, and the energy density was 1.15 J/cm ³ .

Example 3

A high energy storage density strontium zirconate doped copper sodium calcium cadmium titanate ceramic, the composition of the ceramic is Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ -0.08SrZrO ₃ .

The preparation method is the same as in Example 1, the difference is that: according to the composition formula Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ , weigh _{0.31797gNa2CO3} , _{0.40036gCaCO3 ,} 1.2841gCdO, 4.773gCuO, _5.1096gTiO2 ; according to the composition The general formula SrZrO ₃ weighs 2.36208g SrCO ₃ and 1.97152g ZrO ₂ .

The sintered ceramic sample was polished to 200 μm with sandpaper, and the upper and lower surfaces of the ceramic were brushed with silver paste for electrical performance testing. The dielectric constant of the obtained ceramic material was 6600 at 1 kHz, the breakdown field strength was 75 kV/cm, and the energy density was 1.64 J/cm ³ .

Example 4

A high energy storage density strontium zirconate doped copper sodium calcium cadmium titanate ceramic, the composition of the ceramic is Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ -0.1SrZrO ₃ .

The preparation method is the same as in Example 1, the difference is that: according to the composition formula Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ , weigh _{0.31797gNa2CO3} , _{0.40036gCaCO3 ,} 1.2841gCdO, 4.773gCuO, _5.1096gTiO2 ; according to the composition The general formula SrZrO ₃ weighs 2.9526g SrCO ₃ and 2.4644g ZrO ₂ .

The sintered ceramic sample was polished to 200 μm with sandpaper, and the upper and lower surfaces of the ceramic were brushed with silver paste for electrical performance testing. The dielectric constant of the obtained ceramic material was 6100 at 1 kHz, the breakdown field strength was 70 kV/cm, and the energy density was 1.32J/cm ³ .

Example 5

A high energy storage density strontium zirconate doped copper sodium calcium cadmium titanate ceramic, the composition of the ceramic is Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ -0.03SrZrO ₃ .

The preparation method is the same as in Example 1, the difference is that: according to the composition formula Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ , weigh _{0.31797gNa2CO3} , _{0.40036gCaCO3 ,} 1.2841gCdO, 4.773gCuO, _5.1096gTiO2 ; according to the composition The general formula SrZrO ₃ weighs 0.88578g SrCO ₃ and 0.73932g ZrO ₂ .

The sintered ceramic sample was polished to 200 μm with sandpaper, and the upper and lower surfaces of the ceramic were brushed with silver paste for electrical performance testing. The dielectric constant of the obtained ceramic material was 7900 at 1 kHz, the breakdown field strength was 62 kV/cm, and the energy density was 1.34 J/cm ³ .

Example 6

A high energy storage density strontium zirconate doped copper sodium calcium cadmium titanate ceramic, the composition of the ceramic is Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ -0.07SrZrO ₃ .

The preparation method is the same as in Example 1, the difference is that: according to the composition formula Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ , weigh _{0.31797gNa2CO3} , _{0.40036gCaCO3 ,} 1.2841gCdO, 4.773gCuO, _5.1096gTiO2 ; according to the composition The general formula SrZrO ₃ weighs 2.06682g SrCO ₃ and 1.72508g ZrO ₂ .

The sintered ceramic sample was polished to 200 μm with sandpaper, and the upper and lower surfaces of the ceramic were brushed with silver paste for electrical performance testing. The dielectric constant of the obtained ceramic material was 6800 at 1 kHz, the breakdown field strength was 78 kV/cm, and the energy density was 1.83 J/cm ³ .

Comparative example 1

A copper sodium calcium cadmium titanate ceramic, the composition of which is Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ .

The preparation method of the above-mentioned sodium copper titanate calcium cadmium ceramics comprises the following steps:

S1. According to the general composition formula Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ , weigh 0.31797gNa ₂ CO ₃ , 0.40036gCaCO ₃ , 1.2841gCdO, 4.773gCuO, 5.1096gTiO ₂ and place them in the ball mill jar, then place the ball mill jar Powder A was obtained after fully grinding in a ball mill for 16 hours;

S2. Raise the temperature of powder A to 900°C at 3°C/min, and sinter in air atmosphere for 7 hours to obtain Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ powder C; after fully grinding for 18 hours, add 3 wt% of the powder mass The polyvinyl alcohol binder is granulated, and pressed into a ceramic green body with a diameter of 1 cm and a thickness of 0.8 mm under 220 MPa;

S3. Heat up the ceramic body at 2°C/min to 600°C, heat it for 3 hours and discharge glue, then heat it up to 1150°C at 5°C/min, hold it for 8 hours, and cool it with the furnace to get Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ ceramic.

The sintered ceramic sample was polished to 200 μm with sandpaper, and the upper and lower surfaces of the ceramic were brushed with silver paste for electrical performance testing. The dielectric constant of the obtained ceramic material was 13800 at 1 kHz, the breakdown field strength was 5.7 kV/cm, and the energy density It is 0.019J/cm ³ .

Silver electrodes were prepared on the surfaces of the ceramic samples prepared in Examples 1-5 and Comparative Example 1 above to conduct electrical performance tests. The inventor adopts SmartLab SE type ray diffractometer (Japan), Renishaw confocal laser Raman spectrometer (UK), 4294A precision impedance analyzer (U.S.) produced by Agilent Technologies Co., Ltd. and Keithley KEITHLEY 4200 test system ( The United States) conducts characterization tests on the crystal structure, microscopic morphology and electrical properties of ceramic materials, and uses the following formulas to calculate relevant performance parameters.

Dielectric constant: ε _r =Cd/ε ₀ A, C is the capacitance, d is the thickness of the sample, ε ₀ is the vacuum dielectric constant (8.85×10 ^{- 12} F/m), and A is the area of the electrode.

Nonlinear coefficients: U ₁ and U ₂ are the corresponding voltages when I ₁ =0.1mA and I ₂ =1mA respectively.

Energy storage density: The energy storage density of linear dielectric materials is determined by the dielectric constant and breakdown field strength, and the energy storage density Where ε ₀ and ε _r are the dielectric constant (8.85×10 ^-12 F/m) and relative permittivity in vacuum respectively; breakdown field strength: /> U ₂ is the voltage when the current is 1mA, and d is the thickness of the ceramic sample.

Fig. 1 is the XRD diagram of the strontium zirconate doped copper sodium calcium cadmium titanate ceramics prepared in the present invention, Examples 1-5 and Comparative Example 1. It can be seen from Figure 1 that the strontium zirconate doped copper sodium titanate calcium cadmium ceramics prepared in Comparative Example 1 and Example 1, Example 2, and Example 5 all have a single perovskite structure without obvious second phases. produce. However, as the doping amount of strontium zirconate increases, the peak of strontium zirconate appears as in Examples 3 and 4.

FIG. 2 is a Raman spectrum of strontium zirconate-doped copper sodium calcium cadmium titanate ceramics prepared in Examples 1-5 and Comparative Example 1 of the present invention. As shown in Figure 2, 441cm ^-1 , 507cm ^-1 , and 572cm ^-1 correspond to the A _g (1), A _g (2) and F _g (3) modes of ACTO ceramics, respectively. Usually the _Ag (1) and _Ag (2) modes correspond to the rotational motion of _TiO6 , while the _Fg (3) originates from the anti-stretching atomic motion of O-Ti-O. In addition, the Raman spectrum of Example 4 At 454cm ^-1 and 607cm ^-1 , the characteristic mode of strontium zirconate appeared, which corresponds to the largest doping amount of strontium zirconate. This is because the doping amount of strontium zirconate in Example 4 is the largest, so it will show obvious characteristic peaks.

Fig. 3 shows the variation of dielectric constant with frequency of strontium zirconate-doped copper sodium calcium cadmium titanate ceramics prepared in Examples 1-5 and Comparative Example 1 of the present invention. As shown in Figure 3, the dielectric constant of copper sodium calcium cadmium titanate decreased after strontium zirconate doping, and the dielectric constant decreased from 13800 to 6100-8300 at 1kHz, but the dielectric constant decreased at a frequency of 10 ² -10 ⁶ Stability in the Hz range has been improved.

Fig. 4 is a graph showing the variation of nonlinear coefficient, breakdown field strength and energy storage density of strontium zirconate-doped copper sodium calcium cadmium titanate ceramics prepared in Examples 1-5 and Comparative Example 1 of the present invention. It can be seen from Figure 4 that strontium zirconate doping improves the nonlinear coefficient and breakdown field strength of the copper sodium calcium cadmium titanate ceramic material, which is obviously beneficial to the improvement of energy storage density. The energy storage density of undoped copper sodium calcium cadmium titanate in Comparative Example 1 is only 0.019J/cm ³ ; while the energy density of Examples 1-5 after strontium zirconate doping is 1.15-2.23J/cm ³ , Especially in Example 1, the energy density of Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ -0.05SrZrO ₃ ceramics reaches 2.23J/cm ³ , which is significantly higher than the energy storage density of similar ceramic materials. It can be seen that the strontium zirconate doped copper sodium titanate calcium cadmium ceramics obtained in the present invention have the advantages of high energy storage density, simple process, low cost and good repeatability. Capacitors and other fields have very important application prospects.

It should be noted that when the present invention involves a numerical range, it should be understood that the two endpoints of each numerical range and any value between the two endpoints can be selected. Since the steps and methods adopted are the same as the implementation cases, in order to avoid repeating , the present invention describes preferred implementation cases. While preferred embodiments of the invention have been described, additional changes and modifications can be made to these embodiments by those skilled in the art once the basic inventive concept is appreciated. Therefore, the appended claims are intended to be interpreted to cover the preferred embodiments and all changes and modifications which fall within the scope of the invention.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and equivalent technologies thereof, the present invention also intends to include these modifications and variations.

Claims (9)

1. A strontium zirconate doped copper sodium calcium cadmium titanate ceramic with high energy storage density is characterized in that the chemical general formula of the ceramic is Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ -xSrZrO ₃ Wherein x is SrZrO ₃ Take up Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ 0 mass percent of (C)<x≤0.1。

2. The high energy storage density strontium zirconate doped copper sodium calcium cadmium titanate ceramic according to claim 1 wherein x is greater than or equal to 0.02 and less than or equal to 0.08.

3. A method for preparing the high energy storage density strontium zirconate doped copper sodium calcium cadmium titanate ceramic according to claim 1 or 2, comprising the steps of:

s1, selecting Na ₂ CO ₃ 、CaCO ₃ 、CdO、CuO、TiO ₂ 、SrCO ₃ And ZrO(s) ₂ Is raw material powder, according to the composition general formula Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ And SrZrO ₃ Batching, grinding to obtain uniformly mixed powder A and powder B respectively;

s2, sintering the powder A to obtain Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ Powder C; sintering the powder B to obtain SrZrO ₃ Powder D; powder C and powder D are mixed according to a chemical formula Na _0.3 Ca _0.2 Cd _0.5 Cu ₃ Ti ₄ O ₁₂ -xSrZrO ₃ Proportionally mixing, grinding, and adding adhesiveGranulating and pressing to obtain a ceramic blank;

s3, firstly removing glue from the ceramic blank, and then heating and preserving heat to obtain the strontium zirconate doped copper sodium calcium cadmium titanate ceramic.

4. The method for preparing the strontium zirconate-doped copper sodium calcium cadmium titanate ceramic with high energy storage density according to claim 3, wherein in the step S1, the grinding mode is ball milling, and the time is 12-24 hours.

5. The method for preparing the strontium zirconate doped with copper sodium calcium cadmium titanate ceramic with high energy storage density according to claim 3, wherein in S2, the sintering temperature of the powder A is 850-950 ℃, the heat preservation time is 6-8 h, and the heating rate is 2-3 ℃/min.

6. The method for preparing the strontium zirconate doped with copper sodium calcium cadmium titanate ceramic with high energy storage density according to claim 3, wherein in S2, the sintering temperature of the powder B is 1100-1200 ℃, the heat preservation time is 3-4 h, and the heating rate is 3-4 ℃/min.

7. The method for preparing the strontium zirconate doped with copper sodium calcium cadmium titanate ceramic with high energy storage density according to claim 3, wherein in S2, the binder is polyvinyl alcohol, and the addition amount of the polyvinyl alcohol is 3-4wt% of the mass of the ground powder.

8. The method for preparing the strontium zirconate-doped copper sodium calcium cadmium titanate ceramic with high energy storage density according to claim 3, wherein in S2, the pressure of the compression molding is 200-250 MPa; the size of the ceramic body is 1cm in diameter and 0.7-0.8 mm in thickness.

9. The method for preparing the strontium zirconate doped with copper sodium calcium cadmium titanate ceramic with high energy storage density according to claim 3, wherein in S3, the temperature of the discharged glue is 580-620 ℃, the heat preservation time is 2-3 h, the heating rate is 2-3 ℃/min, the heating temperature is increased to 1150 ℃, the heat preservation time is 6-8 h, and the heating rate is 3-5 ℃/min.