Antiferroelectric ceramic material with temperature stability and energy storage ceramic capacitor

Abstract

The application provides an anti-ferroelectric ceramic material with temperature stability and an energy storage ceramic capacitor. 0.94‑4x+c (Ba1Sr3) x La z Zr y Ti 1‑y Si a Mn b O3, wherein 0<=x<=0.04, 0<=y<=0.05, 0.01<=z<=0.04, 0<=a<=0.008, 0<=b<=0.01, 0<=c<=0.015. The temperature stability of the technical scheme of the application is effectively improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of ceramic electronic component preparation, and particularly relates to a temperature-stable antiferroelectric ceramic material and an energy storage ceramic capacitor with the same. BACKGROUND

[0002] The energy storage ceramic capacitor is an electronic component with technical advantages in absorbing and releasing static energy in a short time / high frequency. The dielectric material is a carrier for the main electrical properties of the capacitor, and the energy storage density of the dielectric material is an important material property. The higher the energy storage density of the dielectric material, the smaller the size of the component, and the more conducive to the integration design of each element in the functional circuit module.

[0003] The antiferroelectric ceramic material has reverse parallel dipoles, and under the stimulation of an applied direct current electric field, the antiparallel dipoles with zero net polarization will evolve into the same direction of the ferroelectric space group. This process can obtain a higher polarization intensity under a certain electric field. Therefore, the disadvantage that the polarization intensity of general ferroelectric / relaxor ferroelectric materials decays with the increase of the electric field is improved. This means that under the same energy storage density, the antiferroelectric material requires a lower applied electric field. Therefore, the ceramic capacitor made of the antiferroelectric material is likely to have higher reliability.

[0004] However, the electric phase transition behavior of the antiferroelectric material represented by lead zirconate PbZrO3 shows typical nonlinear behavior, which means that the phase transition has a sensitive response to external fields such as temperature, frequency, alternating electric field, etc. This will cause the energy storage density of the antiferroelectric material to change dramatically at different temperatures. This will be extremely detrimental to the work of the ceramic capacitor in the variable temperature range of the application requirement. SUMMARY

[0005] In view of the problems in the prior art, the purpose of the present application is to provide an antiferroelectric ceramic material with temperature stability and an energy storage ceramic capacitor thereof.

[0006] According to one aspect of the present application, an antiferroelectric ceramic material with temperature stability is provided, and the composition of the ceramic material is Pb 0.94-4x+c (Ba1-Sr3) x La z Zr y Ti 1-y Si a Mn b O3, wherein 0≤x≤0.04, 0≤y≤0.05, 0.01≤z≤0.04, 0≤a≤0.008, 0≤b≤0.01, 0≤c≤0.015.

[0007] Preferably, 0.01≤x≤0.04.

[0008] Preferred: 0.03≤x≤0.04.

[0009] Preferred: 0.01≤y≤0.05.

[0010] Preferred: z=0.04.

[0011] Preferred: 0.004≤a≤0.008.

[0012] Preferred: 0.002≤b≤0.01.

[0013] Preferred: 0.005≤c≤0.015.

[0014] According to another aspect of the present application, there is provided an energy storage ceramic capacitor comprising the above anti-ferroelectric ceramic material with temperature stability.

[0015] Compared with the prior art, the temperature stability of the technical scheme of the present application is effectively improved, and the ceramic capacitor manufactured based on the material can effectively work in a wide temperature range, and can be used as a fast energy storage element in power, power supply, pulse and other circuit function modules to meet design requirements. BRIEF DESCRIPTION OF DRAWINGS

[0016] Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments with reference to the attached drawings.

[0017] Figure 1 is a grain distribution diagram of the embodiment 4 of the present application under a scanning electron microscope;

[0018] Figure 2 is a test result diagram of the X-ray diffraction lattice structure of the embodiment 4 of the present application;

[0019] Figure 3 is a monopolar hysteresis loop diagram of the sintered embodiment 2 (S2), embodiment 3 (S3) and embodiment 4 (S4) of the present application;

[0020] Figure 4 is a monopolar hysteresis loop diagram of the sintered embodiment 2 (S2) and embodiment 5 (S5) of the present application;

[0021] Figure 5 is a change diagram of the energy storage density of the sintered embodiment 2 (S2), embodiment 3 (S3) and embodiment 4 (S4) of the present application in the range of 25-120℃, working at the respective forward turning electric field;

[0022] Figure 6 is a sample breakdown strength-Weibull distribution diagram of the sintered embodiment 2 (S2) and embodiment 8 (S8) of the present application. DETAILED DESCRIPTION

[0023] Example embodiments now will be described more fully hereinafter with reference to the accompanying drawings. Example embodiments, however, can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the example embodiments to those skilled in the art. Like reference numerals refer to like elements throughout the several views. Like components thus will not be described repeatedly with reference to the drawings.

[0024] In the embodiments of the present application, the composition of the antiferroelectric ceramic material with temperature stability is as follows:

[0025] Pb 0.94-4x+c (Ba1Sr3) x La z Zr y Ti 1-y Si a Mn b O3, wherein 0≤x≤0.04, 0≤y≤0.05,

[0026] 0.01≤z≤0.04, 0≤a≤0.008, 0≤b≤0.01, 0≤c≤0.015.

[0027] Preferably, 0.01≤x≤0.04, and preferably 0.03≤x≤0.04. The degree of nonlinearity of the electric phase change is suppressed due to the random field introduced by the increase of x, and the temperature stability is gradually improved in the embodiments of the present application.

[0028] Wherein, 0.01≤z≤0.04, 0≤y≤0.05 jointly determine the lattice structure of the ceramic material. The antiferroelectric material phase transition electric field has a certain range of adjustability. And preferably 0.01≤y≤0.05.

[0029] In particular, preferably z=0.04, suppresses the oxygen vacancy defects of the antiferroelectric material, and improves the breakdown strength of the antiferroelectric material, so that the antiferroelectric-ferroelectric phase transition occurs completely.

[0030] In addition, preferably 0.004≤a≤0.008, 0.002≤b≤0.01, Si, Mn and Pb ions in the material are expected to form a eutectic component, which improves the sintering performance of the antiferroelectric ceramic material.

[0031] Considering the low vapor pressure of Pb-O, the material of the embodiments of the present application may have vacancies of Pb-O in the high temperature process (material synthesis process, high temperature sintering of material to manufacture ceramic capacitors). Therefore, according to different sintering environments, the embodiments of the present application are designed to compensate for 0.005≤c≤0.015.

[0032] The anti-ferroelectric ceramic material with temperature stability of the embodiment of the present application is formed via high-temperature solid-phase synthesis, comprising the following steps:

[0033] All the oxide compositions in the composition are proportionally configured, mixed by water / absolute ethanol, zirconium oxide grinding medium, and at a certain rotating speed.

[0034] After grinding and drying, the dried oxide mixture is made into a raw oxide block under a certain uniaxial pressure with the assistance of a binder.

[0035] The contact area of the raw oxide is increased by the above means, and the target ceramic material is finally synthesized at a high temperature of 800-900°C.

[0036] Preferably, the synthesis temperature is 875-900°C, at which the anti-ferroelectric ceramic material is most fully reacted and is suitable for subsequent sintering and manufacturing of ceramic capacitors.

[0037] Embodiments 1-8:

[0038] Embodiments 1-8 of the present application are prepared by the above method, and the key parameters x, y, z, a, b, and c of embodiments 1-8 of the present application are shown in Table 1 below. The specific steps include:

[0039] All the oxide compositions in the composition are proportionally configured, mixed by water / absolute ethanol as a grinding solvent, zirconium oxide balls as a grinding medium, and in a closed nylon ball mill tank. The ball milling rate is set to 300 r / min, and the total ball milling time is 360 min. After grinding and drying, the slurry is separated from the zirconium oxide balls, and the slurry is dried in an oven above 80°C. The dried oxide mixture powder is mixed with 5% mass fraction of PVB-absolute ethanol solvent, and then uniaxially pressed into a raw oxide block with a diameter of 60 mm. The contact area of the raw oxide is increased by the above means, and the formed block is synthesized at a high temperature of 850°C for 180 min to finally generate the target ceramic material.

[0040] In order to characterize the electrical properties of the above embodiments, the anti-ferroelectric ceramic materials in all embodiments will be mixed and ground in water or absolute ethanol by at least one of roller ball milling / planetary ball milling, etc., and dried under the condition that the average particle size of the powder is controlled to be <1 um.

[0041] After drying, uniaxial pressing is performed: after the powder is mixed with 5% wt of polyvinyl alcohol-absolute ethanol solution, a crack-free and non-layered green body is formed after being treated under a uniaxial pressure of >100 MPa.

[0042] The green bodies are sintered at a temperature not lower than 15% of the radial shrinkage, and the lowest temperature higher than 15% of the radial shrinkage is recorded as the sintering temperature. The test samples sintered by the example numbers are also recorded as the same example numbers.

[0043] Performance test:

[0044] All the performance parameters of the sintered samples mentioned in the embodiments of the present application are tested by the following scheme.

[0045] After the sintering of the ceramic is completed, the size of the ceramic is processed to the required state for the test, for example, the thickness of the antiferroelectric ceramic is about 150 um for the test of the energy storage density. After the processing is completed, the test surface is cleaned with anhydrous ethanol. The energy storage density, the phase transition electric field, and the breakdown strength are tested, and the surface of the ceramic needs to be metallized. Generally, silver or gold is sintered by vacuum plasma sputtering.

[0046] The energy storage density, the phase transition electric field, and the breakdown strength are tested by the TF Analyser 2000 device of aixACCT Systems Company, and the hysteresis loop of the ceramic under different electric fields is tested. The average grain size is obtained by counting and statistics of the grain size obtained by SEM scanning electron microscopy.

[0047] The performances of different embodiments mainly include the turning electric field, the room temperature energy storage density, the attenuation ratio at 125°C, the maximum amplitude (the maximum increase ratio-the maximum attenuation ratio) in a wide temperature range (25-125°C), the breakdown strength (Weibull distribution characteristics), the sintering temperature, and the grain (average) size. The comparison of the above performances is shown in the following table. The performance advantages of the preferred parameters can be embodied in the following embodiment comparison.

[0048] When the key parameters x, y, z, a, b, and c of the embodiments 1-8 of the present application are implemented according to the following embodiments 1-8, the changes of the phase transition electric field, the energy storage density, and the maximum change amplitude in a wide temperature range of each embodiment are shown in Table 1 below:

[0049] Table 1: Performance table of the phase transition electric field, the energy storage density, and the maximum change amplitude in a wide temperature range

[0050]

[0051] As shown in the above table, examples 1-4 are used to compare the influence of x on the energy storage temperature stability of the antiferroelectric ceramic. The polarization-electric field curves of examples 1-4 are shown in the following figure. Figure 3 The differences in the electrode polarization behavior of examples 2-4 are shown, and the positive turning electric field of examples 1-4 gradually increases as the value of x gradually increases to 0.03. The polarization-electric field curves of examples 2-4 are shown in the following figure. Figure 5The comparison results are intuitively illustrated, and the stability of Examples 1-4 gradually increases as the value of x gradually increases to 0.03. When x is 0.02, the maximum change range of Example 3 at a wide temperature is 14.1, which is 67% of Example 2 and only 49% of Example 1. In particular, when x is 0.03, the maximum change range of Example 4 at a wide temperature is 8.2, which is only 39% of Example 2 and only 28% of Example 1 with x = 0, and the temperature stability is greatly improved.

[0052] Figure 1 With Figure 2 The microstructure and lattice structure of the ceramic grains of Example 4 of the application are characterized, respectively.

[0053] The Figure 4 The monopolar hysteresis loops of Examples 2 and 5 are shown, which reflect the effect of y on the turning field. As the value of y increases, the positive turning field of the example at room temperature decreases.

[0054] The Figure 6 The Weibull distribution difference of the breakdown strength of Examples 2 and 8 is shown, which reflects the effect of c on the breakdown behavior and energy storage characteristics of the antiferroelectric ceramic. As the value of c increases, the energy storage density and breakdown strength of the example are also enhanced.

[0055] At the same time, comparing the breakdown strength of Examples 6 and 5 can also reflect the positive significance of the preferred z = 0.04 for improving the energy storage characteristics.

[0056] Comparing the sintering temperature and grain size of Examples 7 and 2 can reflect the positive effect of a and b on the sintering characteristics of the antiferroelectric ceramic, respectively.

[0057] In summary, the temperature stability of the examples of the application is effectively improved, and the ceramic capacitor manufactured based on the material can work effectively in a wide temperature range, and can be used as a fast energy storage element in power, power supply, pulse and other circuit function modules to meet design requirements.

[0058] The above is a further detailed description of the application in combination with specific preferred embodiments, and cannot be considered as limiting the specific implementation of the application to these descriptions. For ordinary skilled persons in the technical field to which the application belongs, without departing from the concept of the application, a number of simple deductions or substitutions can be made, which should be considered as falling within the protection scope of the application.

Claims

1. An antiferroelectric ceramic material having temperature stability, characterized in that, The ceramic material has a composition of Pb 0.94-4x+c (Ba1Sr3) x La z Zr y Ti 1-y Si a Mn b O3, wherein 0.01 < x < 0.04, 0 < y < 0.05, 0.01 < z < 0.04, 0 < a < 0.008, 0 < b < 0.01, 0 < c < 0.

015.

2. The antiferroelectric ceramic material with temperature stability according to claim 1, characterized in that: 0.03≤x≤0.04。 3. The antiferroelectric ceramic material with temperature stability according to claim 1, characterized in that: 0.01≤ y ≤0.05。 4. The antiferroelectric ceramic material with temperature stability according to claim 1, characterized in that: z=0.04。 5. The antiferroelectric ceramic material with temperature stability according to claim 1, characterized in that: 0.004≤a≤0.008。 6. The antiferroelectric ceramic material with temperature stability according to claim 1, characterized in that: 0.002≤b≤0.01。 7. The antiferroelectric ceramic material with temperature stability according to claim 1, characterized in that: 0.005≤c≤0.015。 8. An energy storage ceramic capacitor characterized by: A material having temperature-stable antiferroelectric properties according to any one of claims 1-7.

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