TiO2@SiO2@BaTiO3 composite ceramic powder material, and preparation method and application thereof

Abstract

The application relates to a TiO2@SiO2@BaTiO3 composite ceramic powder material and a preparation method and application thereof. The TiO2@SiO2@BaTiO3 composite ceramic powder material comprises BaTiO3 ceramic powder as an inner core, and a SiO2 layer and a TiO2 layer which are sequentially coated on the surface of the BaTiO3 ceramic powder; the SiO2 layer is composed of a SiO2 phase; the TiO2 layer is composed of a TiO2 phase; the mass content of the SiO2 phase in the TiO2@SiO2@BaTiO3 composite ceramic powder material is 0.5-5%, and the content of the TiO2 phase is 0.3-1.5%.

Description

Technical Field

[0001] This invention relates to a composite ceramic capacitor material, specifically to a TiO2@SiO2@BaTiO3 composite ceramic powder material with high dielectric constant, low dielectric loss, and stable dielectric temperature change rate, as well as its preparation method and application, belonging to the field of chip ceramic capacitor materials. Background Technology

[0002] Multilayer ceramic capacitors (mLCCs) are made by stacking ceramic dielectric films with printed electrodes (internal electrodes) in a staggered manner, sintering them at high temperature in one go to form a ceramic chip, and then sealing the two ends of the chip with metal layers (external electrodes) to form a monolithic structure.

[0003] In recent years, capacitors, as one of the three major passive components, have been widely used in defense technology, aerospace, electric vehicles, electronic equipment, wireless communication, chemical, biomedical, and environmental energy fields. To meet the needs of specific applications or extreme environments, ceramic capacitors are rapidly developing towards higher energy storage and wider temperature ranges. Based on the temperature characteristics of the ceramic dielectric material, mLCCs are generally classified into two types: Type I ceramic dielectrics and Type II ceramic dielectrics. Type I ceramic capacitors are generally made of simple oxides or titanates and typically have smaller capacitance, while Type II ceramic capacitors, represented by BaTiO3, are widely used due to their higher dielectric constant and lower loss characteristics.

[0004] Currently, the application environment requires ceramic capacitors to maintain a relatively stable dielectric constant (i.e., ΔC / C25 < 15%) between -55℃ and 150℃. However, barium titanate undergoes a crystal structure transformation with temperature changes, resulting in spontaneous polarization. Near the Curie temperature (approximately 128℃), the dielectric constant of barium titanate undergoes a sudden change, significantly impacting its application as an mLCC. Most studies on BaTiO3 typically use doping with certain inorganic oxides to improve its dielectric properties, but adding even small amounts of inorganic oxides makes it difficult to shift the Curie peak by nearly 22℃. Furthermore, oxide doping in BaTiO3 easily induces abnormal grain growth, which is detrimental to maintaining a high dielectric constant in barium titanate, leading to a decrease in its energy storage capacity. Summary of the Invention

[0005] To address the drawbacks of barium titanate, such as unstable dielectric constant and tendency for abnormal grain growth, this invention aims to provide a barium titanate-based ceramic composite material with excellent high-temperature stability prepared from a sol-gel, and its preparation method. The invention also includes a BaTiO3-based mLCC material with a dielectric constant of 2500–3500, a dielectric constant of less than 15%, low cost, and ease of mass production, along with its preparation method, and a capacitor made from this composite material.

[0006] On one hand, the present invention provides a TiO2@SiO2@BaTiO3 composite ceramic powder material, comprising: BaTiO3 ceramic powder as a core, and a SiO2 layer coated on the surface of the BaTiO3 ceramic powder; the SiO2 layer is composed of SiO2 phase; the mass content of SiO2 phase in the SiO2@BaTiO3 composite ceramic powder material is 0.5-5%.

[0007] Preferably, the TiO2 phase in the TiO2@SiO2@BaTiO3 composite ceramic powder material has a mass content of 0.3-1.5%, more preferably 0.3-1 wt%, and even more preferably 0.5-1 wt%.

[0008] Preferably, the particle size of the BaTiO3 ceramic powder is 100–900 nm.

[0009] Preferably, the SiO2 layer has a thickness of 10–50 nm and is prepared using tetraethyl orthosilicate as a raw material.

[0010] Preferably, the thickness of the TiO2 layer is 10-30 nm, and it is prepared using a titanium di(2-hydroxypropionic acid)dihydrogen hydroxide solution as a raw material (specifically, using titanium di(2-hydroxypropionic acid)dihydrogen hydroxide as a precursor, ammonium lactate as a polyelectrolyte, adjusting the pH of the solution, and synthesizing anatase TiO2 shell).

[0011] Preferably, the dielectric constant of the TiO2@SiO2@BaTiO3 composite ceramic powder material is 2500–3500, and the dielectric loss is less than 2.5 × 10⁻⁶. -2 (1MHz).

[0012] On the other hand, the present invention provides a method for preparing TiO2@SiO2@BaTiO3 composite ceramic powder material, comprising:

[0013] (1) BaTiO3 powder is mixed with at least one acid solution selected from glacial acetic acid solution, nitric acid solution and hydrochloric acid solution to improve the ionic surface charge of BaTiO3 powder and obtain surface-activated barium titanate mixed solution 1.

[0014] (2) Mix the surface-activated barium titanate mixed solution 1 with tetraethyl orthosilicate (TEOS) to obtain a tetraethyl orthosilicate-acid-barium titanate mixed solution 2;

[0015] (3) Ammonia water was added dropwise to a mixed solution 2 of tetraethyl orthosilicate-acid-barium titanate. By adjusting the pH and under electrostatic action, SiO2@BaTiO3 composite ceramic powder material was prepared.

[0016] (4) The obtained SiO2@BaTiO3 composite ceramic powder material was added to the di(2-hydroxypropionic acid)diammonium hydroxide titanium solution and mixed to obtain mixed solution 3;

[0017] (5) Ammonia water was added dropwise to mixed solution 3, and TiO2@SiO2@BaTiO3 composite ceramic powder material was prepared by adjusting the pH and under electrostatic action.

[0018] Preferably, in step (1), the solvent of the acid solution is selected from at least one of ethanol, diethylene glycol monomethyl ether, propylene glycol methyl ether and dipropylene glycol dimethyl ether; the concentration of the glacial acetic acid solution, nitric acid solution and hydrochloric acid solution is 1-10 wt%; preferably, BaTiO3 powder is placed in a glacial acetic acid / ethanol solution with a concentration of 1-10 wt%, and first magnetically stirred at 100-300 rpm for 1-12 hours in a constant temperature environment of 30-60°C, then sonicated at 100-300 W for 1-12 hours in a constant temperature environment of 30-60°C, and then filtered and dried to obtain a mixed solution of surface-activated barium titanate;

[0019] More preferably, the total amount of glacial acetic acid in the glacial acetic acid solution does not exceed 20 wt% of the mass of BaTiO3 powder, and the drying temperature is 120°C.

[0020] Preferably, in step (2), the mixed solution 1 of surface-activated barium titanate is placed in a water bath stirrer and heated to 30-60°C, and 1-20 wt% of tetraethyl orthosilicate is added dropwise; then, after being magnetically stirred at 100-300 rpm for 1-12 hours in a constant temperature environment of 30-60°C, it is transferred to an ultrasonic device and sonicated at 100-300W for 1-12 hours to obtain a mixed solution 2 of tetraethyl orthosilicate-acid-barium titanate;

[0021] Preferably, the total amount of tetraethyl orthosilicate does not exceed 15 wt% of the BaTiO3 powder; the purity of the tetraethyl orthosilicate is analytical grade.

[0022] Preferably, in step (3), the mixed solution 2 of tetraethyl orthosilicate-acid-barium titanate is placed in a water bath stirrer and heated to 30-60°C, and 60-100wt% ammonia water is added dropwise to adjust the pH to 9-11 so that the acid solution and tetraethyl orthosilicate fully react to generate SiO2 precipitate, and SiO2 layer is coated onto the surface of BaTiO3 powder under electrostatic action. After this process is completed, the constant temperature is maintained and the magnetic stirring is continued for 2-48 hours.

[0023] Preferably, the concentration of the ammonia solution is 24 wt% to 28 wt%.

[0024] According to the preparation method of claim 5, the SiO2@BaTiO3 composite ceramic powder material is added to a titanium di(2-hydroxypropionic acid)diammonium hydroxide solution in step (4); the concentration of the titanium di(2-hydroxypropionic acid)diammonium hydroxide solution is 20-30 wt%.

[0025] Preferably, the SiO2@BaTiO3 composite ceramic powder material is placed in a 1-10 wt% solution of di(2-hydroxypropionic acid)diammonium hydroxide titanium / ethanol, and first magnetically stirred at 100-300 rpm for 1-12 hours in a constant temperature environment of 30-60°C, and then ultrasonicated at 100-300 W for 1-12 hours in a constant temperature environment of 30-60°C.

[0026] More preferably, the total amount of bis(2-hydroxypropionic acid)diammonium hydroxide titanium in the bis(2-hydroxypropionic acid)diammonium hydroxide titanium solution does not exceed 10 wt% of the mass of BaTiO3 powder.

[0027] According to the preparation method of claim 5, the characteristic is that in step (5), the SiO2@BaTiO3-bis(2-hydroxypropionic acid)diammonium hydroxide titanium mixed solution 3 is placed in a water bath stirrer and heated to 30-60°C, and 60-100wt% ammonia water is added dropwise to adjust the pH to 9-11. The mixture is then transferred to a reaction vessel and reacted at 120-160°C for 2-10 hours, and then naturally cooled to room temperature to prepare TiO2@SiO2@BaTiO3 composite ceramic powder material. Preferably, the TiO2@SiO2@BaTiO3 composite ceramic powder is dissolved in isopropanol and ultrasonically treated. Ammonia is then added to adjust the pH to 10-12, and ultrasonic treatment continues. Next, 3-aminopropyltrimethoxysilane is added dropwise and ultrasonically homogenized. The mixture is then refluxed at 30-60℃ and 200-300 rpm for 1-2 hours. Finally, the mixture is washed sequentially with deionized water and ethanol, and then dried in a constant temperature drying oven at 110-150℃ for 2-24 hours to obtain amino-functionalized TiO2@SiO2@BaTiO3. More preferably, in a reaction vessel, the reaction is carried out at 120-160℃ for 2-10 hours, then naturally cooled to room temperature for separation. The product is weighed, dissolved in isopropanol, and ultrasonically homogenized. Ammonia is added to adjust the pH to 10-12, and the mixture is ultrasonically treated for 5 minutes. Then, 3-aminopropyltrimethoxysilane is added dropwise and ultrasonically homogenized. The mixture is then refluxed at 70℃ and 1000 rpm for 12 hours.

[0028] In another aspect, the present invention provides a high-temperature stable barium titanate composite ceramic capacitor material, which is obtained by granulating and pressing the above-mentioned SiO2@BaTiO3 composite ceramic powder material into sheets, and then sintering it at 1150-1350℃ for 1-4 hours.

[0029] Preferably, the sintering temperature is 1250–1350°C and the time is 1–4 hours.

[0030] Beneficial effects:

[0031] The TiO2@SiO2@BaTiO3 composite ceramic material prepared by this invention exhibits a dielectric constant of 2500–3500 under 1 kHz conditions; and a dielectric loss of less than 2.5 × 10⁻⁶. -2 (1KHz); The temperature change rate (-55℃~150℃) of TiO2@SiO2@BaTiO3 composite ceramic material is less than 15%, and it can be widely used in harsh environments such as aerospace. Attached Figure Description

[0032] Figure 1 The TiO2@SiO2@BaTiO3 composite ceramic material prepared in Example 6 shows that the thickness of the SiO2 layer is about 15 nm.

[0033] Figure 2 The TiO2@SiO2@BaTiO3 composite ceramic material prepared in Example 6 shows that the thickness of the TiO2 layer is about 10 nm and the thickness of the SiO2 layer is about 15 nm. Detailed Implementation

[0034] The present invention will be further illustrated by the following embodiments. It should be understood that the following embodiments are for illustrative purposes only and are not intended to limit the present invention.

[0035] This disclosure discloses a ceramic capacitor, which is a ceramic containing major elements such as Ba, Ti, Si, and O. Specifically, the general chemical formula of barium titanate in this disclosure is TiO2@SiO2@BaTiO3, and the particle size D is... 50 The wavelength range is 200 nm to 800 nm, preferably 300 nm to 600 nm. The TiO2@SiO2@BT powder used in this disclosure can be sintered to a dense state at 1300 °C, and its room-temperature dielectric constant can be 2250–4500 (1 kHz), and its dielectric loss can be 1 × 10⁻⁶. -4 ~2.5×10 -2 (1KHz).

[0036] Specifically, the chemical formula of tetraethyl orthosilicate disclosed is Si(OC2H5)4 (abbreviated as TEOS), which can accelerate hydrolysis in the presence of acid or alkali, and was purchased by Sinopharm Group Pharmaceutical Co., Ltd.

[0037] In this disclosure, the TiO2@SiO2@BaTiO3 composite ceramic powder material comprises: a BaTiO3 phase (abbreviated as BT), a SiO2 phase, and a TiO2 phase. Preferably, the D of the TiO2@SiO2@BaTiO3 composite ceramic powder material is... 50 The preferred wavelength is 300–600 nm.

[0038] A composite material of tetraethyl orthosilicate (TES), BT powder, glacial acetic acid, and ammonia was prepared. Glacial acetic acid was used to improve the surface charge of BT particles, thereby activating their surface. Simultaneously, leveraging the property of TES to accelerate hydrolysis in the presence of acid or alkali, the pH was adjusted during the neutralization reaction of glacial acetic acid and ammonia, causing TES to precipitate silica. Electrostatic interaction was then used to coat the BT powder with SiO2. Because SiO2 coating of the BT powder effectively reduced barium titanate grain growth during sintering after molding, and significantly decreased the dielectric constant corresponding to the Curie peak of barium titanate, the composite material possessed an adjustable dielectric constant and a more stable temperature gradient. Furthermore, TiO2@SiO2@BaTiO3 composite ceramic materials were prepared by reacting bis(2-hydroxypropionic acid)diammonium hydroxide titanium dioxide with SiO2@BaTiO3 composite ceramic powder at 120–160 °C for 2–10 h.

[0039] In this ceramic capacitor material, the mass of BT ceramic can be 83.5%–100% of the total mass of the TiO2@SiO2@BT composite, the mass of SiO2 can be 0.5%–5% of the total mass of the TiO2@SiO2@BT composite, and the mass of TiO2 can be 0.3%–1.5% of the total mass of the TiO2@SiO2@BT composite. At this mass fraction, the composite material can have a higher room-temperature dielectric constant and a more stable dielectric temperature change rate, for example, a room-temperature dielectric constant as high as 3500 (1MHz) and a dielectric temperature change rate of less than 15%. More preferably, the mass of BT ceramic is 85%–99% of the total mass of TiO2@SiO2@BT, the mass of SiO2 is 1%–5% of the total mass of TiO2@SiO2@BT, and the mass of TiO2 is 1% of the total mass of TiO2@SiO2@BT.

[0040] In a preferred embodiment, the BT ceramic raw material used in the ceramic capacitor material is granular with a particle size of 300–600 nm. Because barium titanate undergoes spontaneous polarization at its Curie temperature, forming 90° and 180° domains, the 90° domains counteract the internal stress generated by the change in unit cell volume, thereby reducing the nodal constant of the system. Studies have found that there are no 90° domains below 1 μm, resulting in a significant improvement in the dielectric constant; therefore, nanoscale powder is used to improve its room-temperature dielectric constant.

[0041] This invention discloses a BaTiO3-based ceramic capacitor material with high dielectric constant and high stability. The dielectric constant is between 2500-3500, the dielectric temperature change rate is less than 15%, and the material is low-cost and easily mass-produced. The invention also includes a BaTiO3-based MLCC material, its preparation method, and a capacitor made from this composite material. A method for preparing a barium titanate-based ceramic composite material with excellent high-temperature stability using sol-gel improves the bonding force between the BaTiO3 material and the SiO2 two-phase interface on the surface. This method ensures the material's density, which helps improve the dielectric and dielectric constant stability properties of the barium titanate-based ceramic composite material. This method is low-cost and easy to mass-produce. As an example, the preparation method of the above-mentioned composite ceramic capacitor is illustrated.

[0042] BaTiO3 powder particles were modified with glacial acetic acid to improve the surface charge of BT ions. The BaTiO3 powder was placed in a 6wt% glacial acetic acid / ethanol solution and magnetically stirred at 100-300 rpm for 1-12 hours at a constant temperature of 30-60°C. Then, it was ultrasonicated at a constant temperature of 30-60°C for 1-12 hours to obtain a mixed solution of surface-activated barium titanate. Preferably, the total amount of glacial acetic acid did not exceed 20wt% of the BaTiO3 powder mass. The particle size of the BaTiO3 powder was 100-900 nm.

[0043] Acetic acid-modified BaTiO3 powder particles and tetraethyl orthosilicate (TEOS) were mixed, and the TEOS was uniformly coated on the surface of BaTiO3. The resulting surface-activated barium titanate mixture was placed in a water bath stirrer and heated to 30–60°C, and 1–20 wt% tetraethyl orthosilicate was added dropwise. This mixture was continuously magnetically stirred in a constant temperature environment of 30–60°C for 1–12 hours, and then ultrasonicated for 1–12 hours to obtain a tetraethyl orthosilicate-acetic acid-barium titanate mixture; preferably, the total amount of tetraethyl orthosilicate did not exceed 15 wt% of the mass of BaTiO3 powder. The tetraethyl orthosilicate was of analytical grade.

[0044] A mixed solution of tetraethyl orthosilicate, glacial acetic acid, and barium titanate was placed in a water bath and heated to 30–60°C. 60–100 wt% ammonia was added dropwise to adjust the pH, allowing the glacial acetic acid and tetraethyl orthosilicate to fully react and form SiO2 precipitate, which then coated the surface of the BaTiO3 powder under electrostatic attraction. After this process, the temperature was maintained and the mixture was continuously stirred magnetically for 2–48 hours. The ammonia purity was 24%–28%.

[0045] The SiO2@BaTiO3 composite ceramic powder was placed in a 1-10 wt% solution of di(2-hydroxypropionic acid)diammonium hydroxide titanium / ethanol. The mixture was first magnetically stirred at 100-300 rpm for 1-12 hours in a constant temperature environment of 30-60℃, and then sonicated at 100-300 W for 1-12 hours in a constant temperature environment of 30-60℃.

[0046] More preferably, the total amount of bis(2-hydroxypropionic acid)diammonium hydroxide titanium in the bis(2-hydroxypropionic acid)diammonium hydroxide titanium solution does not exceed 30 wt% of the mass of BaTiO3 powder.

[0047] SiO2@BaTiO3-bis(2-hydroxypropionic acid)diammonium hydroxide titanium mixture 3 was placed in a water bath stirrer and heated to 30-60℃. 60-100wt% ammonia water was added dropwise to adjust the pH to 9-11. The mixture was then transferred to a reaction vessel and reacted at 120-160℃ for 2-10 hours. After natural cooling to room temperature, the mixture was separated. The product was weighed, dissolved in isopropanol, and sonicated until homogeneous. Ammonia water was added to adjust the pH to 10-12, and the mixture was sonicated for 5 minutes. Then, 3-aminopropyltrimethoxysilane was added dropwise and sonicated until homogeneous. The mixture was then refluxed at 70℃ and 1000r / min for 12 hours.

[0048] After washing with deionized water and ethanol in sequence, the product is placed in an oven and dried at a constant temperature of 110-150℃ for 2-24 hours to obtain amino-functionalized TiO2@SiO2@BaTiO3. Once dried, it can be granulated and compressed into tablets.

[0049] In one example, dry pressing requires first adding a binder to the dried TiO2@SiO2@BT powder, granulating and sieving, molding, debinding, and then sintering in air to obtain a highly stable BaTiO3-based dielectric material. The binder can be at least one of PVB, ethyl cellulose, and PVA, and the amount added can be 5–15 wt% of the total mass of the TiO2@SiO2@BT powder. Then, high-temperature sintering at 1050–1350℃ for 1–4 hours yields a ceramic capacitor material with a stable dielectric temperature change rate.

[0050] BT powder is modified with glacial acetic acid to obtain modified BT powder. Modification alters the hydrophilicity of the inorganic material surface, improves the surface charge of BT particles, and activates the BT particles, providing a basis for tetraethyl orthosilicate (TES) coating on the BT surface, thereby reducing interfacial porosity and minimizing losses. The particle size of the BT powder is 300–600 nm. Glacial acetic acid is used as the coupling agent in the modification. TES requires complete hydrolysis at specific temperatures and pH levels, while glacial acetic acid provides an acidic environment free of other impurities, further reducing the porosity of the composite material while strengthening the bonding force between the two components. The amount of coupling agent used can be 0–20% (mass fraction) of the powder, preferably 5%–20%.

[0051] The following examples further illustrate the present invention in detail. It should also be understood that the following examples are only for further explanation of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above description of the present invention are within the scope of protection of the present invention. The specific process parameters, etc., in the following examples are merely examples within a suitable range; that is, those skilled in the art can make appropriate selections within the appropriate range based on the description herein, and are not intended to be limited to the specific values ​​in the examples below.

[0052] Example 1

[0053] (1) Mix anhydrous ethanol, barium titanate, and glacial acetic acid in a mass ratio of 50:20:1. First, stir magnetically at 300 rpm for 40 min in a constant temperature environment of 40℃. Then, sonicate in a constant temperature environment of 40℃ for 40 min to obtain a mixed solution of surface-activated barium titanate.

[0054] (2) The obtained mixed solution of surface-activated barium titanate was placed in a water bath stirrer and heated to 40°C, and 1.5 wt% tetraethyl orthosilicate was added dropwise. After the mixed solution was continuously magnetically stirred in a constant temperature environment of 40°C for 1 hour, it was transferred to an ultrasonic device and sonicated for 40 minutes to obtain a mixed solution of tetraethyl orthosilicate-glacial acetic acid-barium titanate;

[0055] (3) Place the above solution in a water bath stirrer and heat it to 40°C. Add 60% ammonia water to adjust the pH to 9.5 so that glacial acetic acid and tetraethyl orthosilicate can fully react to generate SiO2 precipitate, which is then coated onto the surface of BaTiO3 powder under electrostatic action. After completing this process, maintain a constant temperature and continue to stir magnetically for 48 hours, and then dry at 150°C.

[0056] (4) The SiO2@BaTiO3 composite ceramic powder material was placed in a 2wt% di(2-hydroxypropionic acid)diammonium hydroxide titanium / ethanol solution. First, it was magnetically stirred at 100-300 rpm for 1-12 hours in a constant temperature environment of 30-60℃. Then, it was ultrasonicated at 100-300W for 1-12 hours in a constant temperature environment of 30-60℃.

[0057] (5) Place the SiO2@BaTiO3-di(2-hydroxypropionic acid)diammonium hydroxide titanium mixture 3 in a water bath stirrer and heat to 30-60℃. Add 60-100wt% ammonia water to adjust the pH to 9.5. Transfer the mixture to a reaction vessel and react at 120℃ for 4 hours. After naturally cooling to room temperature, separate the mixture. Weigh the product and dissolve it in isopropanol. Sonicate it until homogeneous. Add ammonia water to adjust the pH to 10. Sonicate for 5 minutes. Add 3-aminopropyltrimethoxysilane and sonicate until homogeneous. Reflux at 70℃ and 1000r / min for 12 hours.

[0058] (6) After washing with deionized water and ethanol in sequence, dry in a constant temperature drying oven at 110-150℃ for 2-24 hours to obtain amino-functionalized TiO2@SiO2@BaTiO3.

[0059] (7) The obtained powder is granulated and dry-pressed into shape;

[0060] (8) Granulation and Dry Pressing: First, a binder is added to the dried TiO2@SiO2@BT powder for granulation and sieving. After molding and debinding, the powder is sintered in air to obtain a highly stable BaTiO3-based dielectric material. The binder can be at least one of PVB, ethyl cellulose, and PVA, and the amount added can be 9 wt% of the total mass of the TiO2@SiO2@BT powder. After sintering, a high-strength, low-temperature co-fired material is finally obtained. The process parameters are listed in Table 1, and the performance test results of the final capacitor material are shown in Table 2.

[0061] Example 2

[0062] (1) Mix anhydrous ethanol, barium titanate, and glacial acetic acid in a mass ratio of 50:20:1. First, stir magnetically at 300 rpm for 40 min in a constant temperature environment of 40℃. Then, sonicate in a constant temperature environment of 40℃ for 40 min to obtain a mixed solution of surface-activated barium titanate.

[0063] (2) The obtained mixed solution of surface-activated barium titanate was placed in a water bath stirrer and heated to 40°C, and 3 wt% tetraethyl orthosilicate was added dropwise. After the mixed solution was continuously magnetically stirred in a constant temperature environment of 40°C for 1 hour, it was transferred to an ultrasonic device and sonicated for 40 minutes to obtain a mixed solution of tetraethyl orthosilicate-glacial acetic acid-barium titanate;

[0064] (3) Place the above solution in a water bath stirrer and heat it to 40°C. Add 60% ammonia water to adjust the pH to 9.5 so that glacial acetic acid and tetraethyl orthosilicate can fully react to generate SiO2 precipitate, which is then coated onto the surface of BaTiO3 powder under electrostatic action. After completing this process, maintain a constant temperature and continue to stir magnetically for 48 hours, and then dry at 150°C.

[0065] (4) The SiO2@BaTiO3 composite ceramic powder material was placed in a 2wt% di(2-hydroxypropionic acid)diammonium hydroxide titanium / ethanol solution. First, it was magnetically stirred at 100-300 rpm for 1-12 hours in a constant temperature environment of 30-60℃. Then, it was ultrasonicated at 100-300W for 1-12 hours in a constant temperature environment of 30-60℃.

[0066] (5) Place the SiO2@BaTiO3-di(2-hydroxypropionic acid)diammonium hydroxide titanium mixture 3 in a water bath stirrer and heat to 30-60℃. Add 60-100wt% ammonia water to adjust the pH to 9.5. Transfer the mixture to a reaction vessel and react at 120℃ for 4 hours. Then, cool naturally to room temperature and separate. Weigh the above product and dissolve it in isopropanol. Sonicate it until homogeneous. Add ammonia water to adjust the pH to 10. Sonicate for 5 minutes. Add 3-aminopropyltrimethoxysilane and sonicate until homogeneous. Reflux at 70℃ and 1000r / min for 12 hours.

[0067] (6) After washing with deionized water and ethanol in sequence, dry in a constant temperature drying oven at 110-150℃ for 2-24 hours to obtain amino-functionalized TiO2@SiO2@BaTiO3.

[0068] (7) The obtained powder is granulated and dry-pressed into shape;

[0069] (8) Granulation and Dry Pressing: First, a binder is added to the dried TiO2@SiO2@BT powder for granulation and sieving. After molding and debinding, the powder is sintered in air to obtain a highly stable BaTiO3-based dielectric material. The binder can be at least one of PVB, ethyl cellulose, and PVA, and the amount added can be 9 wt% of the total mass of the TiO2@SiO2@BT powder. After sintering, a high-strength, low-temperature co-fired material is finally obtained. The process parameters are listed in Table 1, and the performance test results of the final capacitor material are shown in Table 2.

[0070] Example 3

[0071] (1) Mix anhydrous ethanol, barium titanate, and glacial acetic acid in a mass ratio of 50:20:1. First, stir magnetically at 300 rpm for 40 min in a constant temperature environment of 40℃. Then, sonicate in a constant temperature environment of 40℃ for 40 min to obtain a mixed solution of surface-activated barium titanate.

[0072] (2) The obtained mixed solution of surface-activated barium titanate was placed in a water bath stirrer and heated to 40°C, and 6 wt% tetraethyl orthosilicate was added dropwise. After the mixed solution was continuously magnetically stirred in a constant temperature environment of 40°C for 1 hour, it was transferred to an ultrasonic device and sonicated for 40 minutes to obtain a mixed solution of tetraethyl orthosilicate-glacial acetic acid-barium titanate;

[0073] (3) Place the above solution in a water bath stirrer and heat it to 40°C. Add 60% ammonia water to adjust the pH to 9.5 so that glacial acetic acid and tetraethyl orthosilicate can fully react to generate SiO2 precipitate, which is then coated onto the surface of BaTiO3 powder under electrostatic action. After completing this process, maintain a constant temperature and continue to stir magnetically for 48 hours, and then dry at 150°C.

[0074] (4) The SiO2@BaTiO3 composite ceramic powder material was placed in a 2wt% di(2-hydroxypropionic acid)diammonium hydroxide titanium / ethanol solution. First, it was magnetically stirred at 100-300 rpm for 1-12 hours in a constant temperature environment of 30-60℃. Then, it was ultrasonicated at 100-300W for 1-12 hours in a constant temperature environment of 30-60℃.

[0075] (5) Place the SiO2@BaTiO3-di(2-hydroxypropionic acid)diammonium hydroxide titanium mixture 3 in a water bath stirrer and heat to 30-60℃. Add 60-100wt% ammonia water to adjust the pH to 9.5. Transfer the mixture to a reaction vessel and react at 120℃ for 4 hours. After naturally cooling to room temperature, separate the mixture. Weigh the product and dissolve it in isopropanol. Sonicate it until homogeneous. Add ammonia water to adjust the pH to 10. Sonicate for 5 minutes. Add 3-aminopropyltrimethoxysilane and sonicate until homogeneous. Reflux at 70℃ and 1000r / min for 12 hours.

[0076] (6) After washing with deionized water and ethanol in sequence, dry in a constant temperature drying oven at 110-150℃ for 2-24 hours to obtain amino-functionalized TiO2@SiO2@BaTiO3.

[0077] (7) The obtained powder is granulated and dry-pressed into shape;

[0078] (8) Granulation and Dry Pressing: First, a binder is added to the dried TiO2@SiO2@BT powder for granulation and sieving. After molding and debinding, the powder is sintered in air to obtain a highly stable BaTiO3-based dielectric material. The binder can be at least one of PVB, ethyl cellulose, and PVA, and the amount added can be 9 wt% of the total mass of the TiO2@SiO2@BT powder. After sintering, a high-strength, low-temperature co-fired material is finally obtained. The process parameters are listed in Table 1, and the performance test results of the final capacitor material are shown in Table 2.

[0079] Example 4

[0080] (1) Mix anhydrous ethanol, barium titanate, and glacial acetic acid in a mass ratio of 50:20:1. First, stir magnetically at 300 rpm for 40 min in a constant temperature environment of 40℃. Then, sonicate in a constant temperature environment of 40℃ for 40 min to obtain a mixed solution of surface-activated barium titanate.

[0081] (2) The obtained mixed solution of surface-activated barium titanate was placed in a water bath stirrer and heated to 40°C, and 10 wt% tetraethyl orthosilicate was added dropwise. After the mixed solution was continuously magnetically stirred in a constant temperature environment of 40°C for 1 hour, it was transferred to an ultrasonic device and sonicated for 40 minutes to obtain a mixed solution of tetraethyl orthosilicate-glacial acetic acid-barium titanate;

[0082] (3) Place the above solution in a water bath stirrer and heat it to 40°C. Add 60% ammonia water to adjust the pH to 9.5 so that glacial acetic acid and tetraethyl orthosilicate can fully react to generate SiO2 precipitate, which is then coated onto the surface of BaTiO3 powder under electrostatic action. After completing this process, maintain a constant temperature and continue to stir magnetically for 48 hours, and then dry at 150°C.

[0083] (4) The SiO2@BaTiO3 composite ceramic powder material was placed in a 2wt% di(2-hydroxypropionic acid)diammonium hydroxide titanium / ethanol solution. First, it was magnetically stirred at 100-300 rpm for 1-12 hours in a constant temperature environment of 30-60℃. Then, it was ultrasonicated at 100-300W for 1-12 hours in a constant temperature environment of 30-60℃.

[0084] (5) Place the SiO2@BaTiO3-di(2-hydroxypropionic acid)diammonium hydroxide titanium mixture 3 in a water bath stirrer and heat to 30-60℃. Add 60-100wt% ammonia water to adjust the pH to 9.5. Transfer the mixture to a reaction vessel and react at 120℃ for 4 hours. After naturally cooling to room temperature, separate the mixture. Weigh the product and dissolve it in isopropanol. Sonicate it until homogeneous. Add ammonia water to adjust the pH to 10. Sonicate for 5 minutes. Add 3-aminopropyltrimethoxysilane and sonicate until homogeneous. Reflux at 70℃ and 1000r / min for 12 hours.

[0085] (6) After washing with deionized water and ethanol in sequence, dry in a constant temperature drying oven at 110-150℃ for 2-24 hours to obtain amino-functionalized TiO2@SiO2@BaTiO3.

[0086] (7) The obtained powder is granulated and dry-pressed into shape;

[0087] (8) Granulation and Dry Pressing: First, a binder is added to the dried TiO2@SiO2@BT powder for granulation and sieving. After molding and debinding, the powder is sintered in air to obtain a highly stable BaTiO3-based dielectric material. The binder can be at least one of PVB, ethyl cellulose, and PVA, and the amount added can be 9 wt% of the total mass of the TiO2@SiO2@BT powder. After sintering, a high-strength, low-temperature co-fired material is finally obtained. The process parameters are listed in Table 1, and the performance test results of the final capacitor material are shown in Table 2.

[0088] Example 5

[0089] (1) Mix anhydrous ethanol, barium titanate, and glacial acetic acid in a mass ratio of 50:20:1. First, stir magnetically at 300 rpm for 40 min in a constant temperature environment of 40℃. Then, sonicate in a constant temperature environment of 40℃ for 40 min to obtain a mixed solution of surface-activated barium titanate.

[0090] (2) The obtained mixed solution of surface-activated barium titanate was placed in a water bath stirrer and heated to 40°C, and 15 wt% tetraethyl orthosilicate was added dropwise. After the mixed solution was continuously magnetically stirred in a constant temperature environment of 40°C for 1 hour, it was transferred to an ultrasonic device and sonicated for 40 min to obtain a mixed solution of tetraethyl orthosilicate-glacial acetic acid-barium titanate;

[0091] (3) Place the above solution in a water bath stirrer and heat it to 40°C. Add 60% ammonia water to adjust the pH to 9.5 so that glacial acetic acid and tetraethyl orthosilicate can fully react to generate SiO2 precipitate, which is then coated onto the surface of BaTiO3 powder under electrostatic action. After completing this process, maintain a constant temperature and continue to stir magnetically for 48 hours, and then dry at 150°C.

[0092] (4) The SiO2@BaTiO3 composite ceramic powder material was placed in a 2wt% di(2-hydroxypropionic acid)diammonium hydroxide titanium / ethanol solution. First, it was magnetically stirred at 100-300 rpm for 1-12 hours in a constant temperature environment of 30-60℃. Then, it was ultrasonicated at 100-300W for 1-12 hours in a constant temperature environment of 30-60℃.

[0093] (5) Place the SiO2@BaTiO3-di(2-hydroxypropionic acid)diammonium hydroxide titanium mixture 3 in a water bath stirrer and heat to 30-60℃. Add 60-100wt% ammonia water to adjust the pH to 9.5. Transfer the mixture to a reaction vessel and react at 120℃ for 4 hours. After naturally cooling to room temperature, separate the mixture. Weigh the product and dissolve it in isopropanol. Sonicate it until homogeneous. Add ammonia water to adjust the pH to 10. Sonicate for 5 minutes. Add 3-aminopropyltrimethoxysilane and sonicate until homogeneous. Reflux at 70℃ and 1000r / min for 12 hours.

[0094] (6) After washing with deionized water and ethanol in sequence, dry in a constant temperature drying oven at 110-150℃ for 2-24 hours to obtain amino-functionalized TiO2@SiO2@BaTiO3.

[0095] (7) The obtained powder is granulated and dry-pressed into shape;

[0096] (8) Granulation and Dry Pressing: First, a binder is added to the dried TiO2@SiO2@BT powder for granulation and sieving. After molding and debinding, the powder is sintered in air to obtain a highly stable BaTiO3-based dielectric material. The binder can be at least one of PVB, ethyl cellulose, and PVA, and the amount added can be 9 wt% of the total mass of the TiO2@SiO2@BT powder. After sintering, a high-strength, low-temperature co-fired material is finally obtained. The process parameters are listed in Table 1, and the performance test results of the final capacitor material are shown in Table 2.

[0097] Example 6

[0098] (1) Mix anhydrous ethanol, barium titanate, and glacial acetic acid in a mass ratio of 50:20:1. First, stir magnetically at 300 rpm for 40 min in a constant temperature environment of 40℃. Then, sonicate in a constant temperature environment of 40℃ for 40 min to obtain a mixed solution of surface-activated barium titanate.

[0099] (2) The obtained mixed solution of surface-activated barium titanate was placed in a water bath stirrer and heated to 40°C, and 1.5 wt% tetraethyl orthosilicate was added dropwise. After the mixed solution was continuously magnetically stirred in a constant temperature environment of 40°C for 1 hour, it was transferred to an ultrasonic device and sonicated for 40 minutes to obtain a mixed solution of tetraethyl orthosilicate-glacial acetic acid-barium titanate;

[0100] (3) Place the above solution in a water bath stirrer and heat it to 40°C. Add 60% ammonia water to adjust the pH to 9.5 so that glacial acetic acid and tetraethyl orthosilicate can fully react to generate SiO2 precipitate, which is then coated onto the surface of BaTiO3 powder under electrostatic action. After completing this process, maintain a constant temperature and continue to stir magnetically for 48 hours, and then dry at 150°C.

[0101] (4) The SiO2@BaTiO3 composite ceramic powder material was placed in a 4wt% di(2-hydroxypropionic acid)diammonium hydroxide titanium / ethanol solution. First, it was magnetically stirred at 100-300 rpm for 1-12 hours in a constant temperature environment of 30-60℃. Then, it was ultrasonicated at 100-300W for 1-12 hours in a constant temperature environment of 30-60℃.

[0102] (5) Place the SiO2@BaTiO3-di(2-hydroxypropionic acid)diammonium hydroxide titanium mixture 3 in a water bath stirrer and heat to 30-60℃. Add 60-100wt% ammonia water to adjust the pH to 9.5. Transfer the mixture to a reaction vessel and react at 120℃ for 4 hours. After naturally cooling to room temperature, separate the mixture. Weigh the product and dissolve it in isopropanol. Sonicate it until homogeneous. Add ammonia water to adjust the pH to 10. Sonicate for 5 minutes. Add 3-aminopropyltrimethoxysilane and sonicate until homogeneous. Reflux at 70℃ and 1000r / min for 12 hours.

[0103] (6) After washing with deionized water and ethanol in sequence, dry in a constant temperature drying oven at 110-150℃ for 2-24 hours to obtain amino-functionalized TiO2@SiO2@BaTiO3.

[0104] (7) The obtained powder is granulated and dry-pressed into shape;

[0105] (8) Granulation and Dry Pressing: First, a binder is added to the dried TiO2@SiO2@BT powder for granulation and sieving. After molding and debinding, the powder is sintered in air to obtain a highly stable BaTiO3-based dielectric material. The binder can be at least one of PVB, ethyl cellulose, and PVA, and the amount added can be 9 wt% of the total mass of the TiO2@SiO2@BT powder. After sintering, a high-strength, low-temperature co-fired material is finally obtained. The process parameters are listed in Table 1, and the performance test results of the final capacitor material are shown in Table 2.

[0106] Example 7

[0107] (1) Mix anhydrous ethanol, barium titanate, and glacial acetic acid in a mass ratio of 50:20:1. First, stir magnetically at 300 rpm for 40 min in a constant temperature environment of 40℃. Then, sonicate in a constant temperature environment of 40℃ for 40 min to obtain a mixed solution of surface-activated barium titanate.

[0108] (2) The obtained mixed solution of surface-activated barium titanate was placed in a water bath stirrer and heated to 40°C, and 3 wt% tetraethyl orthosilicate was added dropwise. After the mixed solution was continuously magnetically stirred in a constant temperature environment of 40°C for 1 hour, it was transferred to an ultrasonic device and sonicated for 40 minutes to obtain a mixed solution of tetraethyl orthosilicate-glacial acetic acid-barium titanate;

[0109] (3) Place the above solution in a water bath stirrer and heat it to 40°C. Add 60% ammonia water to adjust the pH to 9.5 so that glacial acetic acid and tetraethyl orthosilicate can fully react to generate SiO2 precipitate, which is then coated onto the surface of BaTiO3 powder under electrostatic action. After completing this process, maintain a constant temperature and continue to stir magnetically for 48 hours, and then dry at 150°C.

[0110] (4) The SiO2@BaTiO3 composite ceramic powder material was placed in a 4wt% di(2-hydroxypropionic acid)diammonium hydroxide titanium / ethanol solution. First, it was magnetically stirred at 100-300 rpm for 1-12 hours in a constant temperature environment of 30-60℃. Then, it was ultrasonicated at 100-300W for 1-12 hours in a constant temperature environment of 30-60℃.

[0111] (5) Place the SiO2@BaTiO3-di(2-hydroxypropionic acid)diammonium hydroxide titanium mixture 3 in a water bath stirrer and heat to 30-60℃. Add 60-100wt% ammonia water to adjust the pH to 9.5. Transfer the mixture to a reaction vessel and react at 120℃ for 4 hours. After naturally cooling to room temperature, separate the mixture. Weigh the product and dissolve it in isopropanol. Sonicate it until homogeneous. Add ammonia water to adjust the pH to 10. Sonicate for 5 minutes. Add 3-aminopropyltrimethoxysilane and sonicate until homogeneous. Reflux at 70℃ and 1000r / min for 12 hours.

[0112] (6) After washing with deionized water and ethanol in sequence, dry in a constant temperature drying oven at 110-150℃ for 2-24 hours to obtain amino-functionalized TiO2@SiO2@BaTiO3.

[0113] (7) The obtained powder is granulated and dry-pressed into shape;

[0114] (8) Granulation and Dry Pressing: First, a binder is added to the dried TiO2@SiO2@BT powder for granulation and sieving. After molding and debinding, the powder is sintered in air to obtain a highly stable BaTiO3-based dielectric material. The binder can be at least one of PVB, ethyl cellulose, and PVA, and the amount added can be 9 wt% of the total mass of the TiO2@SiO2@BT powder. After sintering, a high-strength, low-temperature co-fired material is finally obtained. The process parameters are listed in Table 1, and the performance test results of the final capacitor material are shown in Table 2.

[0115] Example 8

[0116] (1) Mix anhydrous ethanol, barium titanate, and glacial acetic acid in a mass ratio of 50:20:1. First, stir magnetically at 300 rpm for 40 min in a constant temperature environment of 40℃. Then, sonicate in a constant temperature environment of 40℃ for 40 min to obtain a mixed solution of surface-activated barium titanate.

[0117] (2) The obtained mixed solution of surface-activated barium titanate was placed in a water bath stirrer and heated to 40°C, and 6 wt% tetraethyl orthosilicate was added dropwise. After the mixed solution was continuously magnetically stirred in a constant temperature environment of 40°C for 1 hour, it was transferred to an ultrasonic device and sonicated for 40 minutes to obtain a mixed solution of tetraethyl orthosilicate-glacial acetic acid-barium titanate;

[0118] (3) Place the above solution in a water bath stirrer and heat it to 40°C. Add 60% ammonia water to adjust the pH to 9.5 so that glacial acetic acid and tetraethyl orthosilicate can fully react to generate SiO2 precipitate, which is then coated onto the surface of BaTiO3 powder under electrostatic action. After completing this process, maintain a constant temperature and continue to stir magnetically for 48 hours, and then dry at 150°C.

[0119] (4) The SiO2@BaTiO3 composite ceramic powder material was placed in a 4wt% di(2-hydroxypropionic acid)diammonium hydroxide titanium / ethanol solution. First, it was magnetically stirred at 100-300 rpm for 1-12 hours in a constant temperature environment of 30-60℃. Then, it was ultrasonicated at 100-300W for 1-12 hours in a constant temperature environment of 30-60℃.

[0120] (5) Place the SiO2@BaTiO3-di(2-hydroxypropionic acid)diammonium hydroxide titanium mixture 3 in a water bath stirrer and heat to 30-60℃. Add 60-100wt% ammonia water to adjust the pH to 9.5. Transfer the mixture to a reaction vessel and react at 120℃ for 4 hours. After naturally cooling to room temperature, separate the mixture. Weigh the product and dissolve it in isopropanol. Sonicate it until homogeneous. Add ammonia water to adjust the pH to 10. Sonicate for 5 minutes. Add 3-aminopropyltrimethoxysilane and sonicate until homogeneous. Reflux at 70℃ and 1000r / min for 12 hours.

[0121] (6) After washing with deionized water and ethanol in sequence, dry in a constant temperature drying oven at 110-150℃ for 2-24 hours to obtain amino-functionalized TiO2@SiO2@BaTiO3.

[0122] (7) The obtained powder is granulated and dry-pressed into shape;

[0123] (8) Granulation and Dry Pressing: First, a binder is added to the dried TiO2@SiO2@BT powder for granulation and sieving. After molding and debinding, the powder is sintered in air to obtain a highly stable BaTiO3-based dielectric material. The binder can be at least one of PVB, ethyl cellulose, and PVA, and the amount added can be 9 wt% of the total mass of the TiO2@SiO2@BT powder. After sintering, a high-strength, low-temperature co-fired material is finally obtained. The process parameters are listed in Table 1, and the performance test results of the final capacitor material are shown in Table 2.

[0124] Example 9

[0125] (1) Mix anhydrous ethanol, barium titanate, and glacial acetic acid in a mass ratio of 50:20:1. First, stir magnetically at 300 rpm for 40 min in a constant temperature environment of 40℃. Then, sonicate in a constant temperature environment of 40℃ for 40 min to obtain a mixed solution of surface-activated barium titanate.

[0126] (2) The obtained mixed solution of surface-activated barium titanate was placed in a water bath stirrer and heated to 40°C, and 10 wt% tetraethyl orthosilicate was added dropwise. After the mixed solution was continuously magnetically stirred in a constant temperature environment of 40°C for 1 hour, it was transferred to an ultrasonic device and sonicated for 40 minutes to obtain a mixed solution of tetraethyl orthosilicate-glacial acetic acid-barium titanate;

[0127] (3) Place the above solution in a water bath stirrer and heat it to 40°C. Add 60% ammonia water to adjust the pH to 9.5 so that glacial acetic acid and tetraethyl orthosilicate can fully react to generate SiO2 precipitate, which is then coated onto the surface of BaTiO3 powder under electrostatic action. After completing this process, maintain a constant temperature and continue to stir magnetically for 48 hours, and then dry at 150°C.

[0128] (4) The SiO2@BaTiO3 composite ceramic powder material was placed in a 4wt% di(2-hydroxypropionic acid)diammonium hydroxide titanium / ethanol solution. First, it was magnetically stirred at 100-300 rpm for 1-12 hours in a constant temperature environment of 30-60℃. Then, it was ultrasonicated at 100-300W for 1-12 hours in a constant temperature environment of 30-60℃.

[0129] (5) Place the SiO2@BaTiO3-di(2-hydroxypropionic acid)diammonium hydroxide titanium mixture 3 in a water bath stirrer and heat to 30-60℃. Add 60-100wt% ammonia water to adjust the pH to 9.5. Transfer the mixture to a reaction vessel and react at 120℃ for 4 hours. After naturally cooling to room temperature, separate the mixture. Weigh the product and dissolve it in isopropanol. Sonicate it until homogeneous. Add ammonia water to adjust the pH to 10. Sonicate for 5 minutes. Add 3-aminopropyltrimethoxysilane and sonicate until homogeneous. Reflux at 70℃ and 1000r / min for 12 hours.

[0130] (6) After washing with deionized water and ethanol in sequence, dry in a constant temperature drying oven at 110-150℃ for 2-24 hours to obtain amino-functionalized TiO2@SiO2@BaTiO3.

[0131] (7) The obtained powder is granulated and dry-pressed into shape;

[0132] (8) Granulation and Dry Pressing: First, a binder is added to the dried TiO2@SiO2@BT powder for granulation and sieving. After molding and debinding, the powder is sintered in air to obtain a highly stable BaTiO3-based dielectric material. The binder can be at least one of PVB, ethyl cellulose, and PVA, and the amount added can be 9 wt% of the total mass of the TiO2@SiO2@BT powder. After sintering, a high-strength, low-temperature co-fired material is finally obtained. The process parameters are listed in Table 1, and the performance test results of the final capacitor material are shown in Table 2.

[0133] Example 10

[0134] (1) Mix anhydrous ethanol, barium titanate, and glacial acetic acid in a mass ratio of 50:20:1. First, stir magnetically at 300 rpm for 40 min in a constant temperature environment of 40℃. Then, sonicate in a constant temperature environment of 40℃ for 40 min to obtain a mixed solution of surface-activated barium titanate.

[0135] (2) The obtained mixed solution of surface-activated barium titanate was placed in a water bath stirrer and heated to 40°C, and 15 wt% tetraethyl orthosilicate was added dropwise. After the mixed solution was continuously magnetically stirred in a constant temperature environment of 40°C for 1 hour, it was transferred to an ultrasonic device and sonicated for 40 min to obtain a mixed solution of tetraethyl orthosilicate-glacial acetic acid-barium titanate;

[0136] (3) Place the above solution in a water bath stirrer and heat it to 40°C. Add 60% ammonia water to adjust the pH to 9.5 so that glacial acetic acid and tetraethyl orthosilicate can fully react to generate SiO2 precipitate, which is then coated onto the surface of BaTiO3 powder under electrostatic action. After completing this process, maintain a constant temperature and continue to stir magnetically for 48 hours, and then dry at 150°C.

[0137] (4) The SiO2@BaTiO3 composite ceramic powder material was placed in a 4wt% di(2-hydroxypropionic acid)diammonium hydroxide titanium / ethanol solution. First, it was magnetically stirred at 100-300 rpm for 1-12 hours in a constant temperature environment of 30-60℃. Then, it was ultrasonicated at 100-300W for 1-12 hours in a constant temperature environment of 30-60℃.

[0138] (5) Place the SiO2@BaTiO3-di(2-hydroxypropionic acid)diammonium hydroxide titanium mixture 3 in a water bath stirrer and heat to 30-60℃. Add 60-100wt% ammonia water to adjust the pH to 9.5. Transfer the mixture to a reaction vessel and react at 120℃ for 4 hours. After naturally cooling to room temperature, separate the mixture. Weigh the product and dissolve it in isopropanol. Sonicate it until homogeneous. Add ammonia water to adjust the pH to 10. Sonicate for 5 minutes. Add 3-aminopropyltrimethoxysilane and sonicate until homogeneous. Reflux at 70℃ and 1000r / min for 12 hours.

[0139] (6) After washing with deionized water and ethanol in sequence, dry in a constant temperature drying oven at 110-150℃ for 2-24 hours to obtain amino-functionalized TiO2@SiO2@BaTiO3.

[0140] (7) The obtained powder is granulated and dry-pressed into shape;

[0141] (8) Granulation and Dry Pressing: First, a binder is added to the dried TiO2@SiO2@BT powder for granulation and sieving. After molding and debinding, the powder is sintered in air to obtain a highly stable BaTiO3-based dielectric material. The binder can be at least one of PVB, ethyl cellulose, and PVA, and the amount added can be 9 wt% of the total mass of the TiO2@SiO2@BT powder. After sintering, a high-strength, low-temperature co-fired material is finally obtained. The process parameters are listed in Table 1, and the performance test results of the final capacitor material are shown in Table 2.

[0142] Example 11

[0143] (1) Mix anhydrous ethanol, barium titanate, and glacial acetic acid in a mass ratio of 50:20:2. First, stir magnetically at 300 rpm for 40 min in a constant temperature environment of 40℃. Then, sonicate in a constant temperature environment of 40℃ for 40 min to obtain a mixed solution of surface-activated barium titanate.

[0144] (2) The obtained mixed solution of surface-activated barium titanate was placed in a water bath stirrer and heated to 40°C, and 1.5 wt% tetraethyl orthosilicate was added dropwise. After the mixed solution was continuously magnetically stirred in a constant temperature environment of 40°C for 1 hour, it was transferred to an ultrasonic device and sonicated for 40 minutes to obtain a mixed solution of tetraethyl orthosilicate-glacial acetic acid-barium titanate;

[0145] (3) Place the above solution in a water bath stirrer and heat it to 40°C. Add 60% ammonia water to adjust the pH to 9.5 so that glacial acetic acid and tetraethyl orthosilicate can fully react to generate SiO2 precipitate, which is then coated onto the surface of BaTiO3 powder under electrostatic action. After completing this process, maintain a constant temperature and continue to stir magnetically for 48 hours, and then dry at 150°C.

[0146] (4) The SiO2@BaTiO3 composite ceramic powder material was placed in a 2wt% di(2-hydroxypropionic acid)diammonium hydroxide titanium / ethanol solution. First, it was magnetically stirred at 100-300 rpm for 1-12 hours in a constant temperature environment of 30-60℃. Then, it was ultrasonicated at 100-300W for 1-12 hours in a constant temperature environment of 30-60℃.

[0147] (5) Place the SiO2@BaTiO3-di(2-hydroxypropionic acid)diammonium hydroxide titanium mixture 3 in a water bath stirrer and heat to 30-60℃. Add 60-100wt% ammonia water to adjust the pH to 9.5. Transfer the mixture to a reaction vessel and react at 120℃ for 4 hours. After naturally cooling to room temperature, separate the mixture. Weigh the product and dissolve it in isopropanol. Sonicate it until homogeneous. Add ammonia water to adjust the pH to 10. Sonicate for 5 minutes. Add 3-aminopropyltrimethoxysilane and sonicate until homogeneous. Reflux at 70℃ and 1000r / min for 12 hours.

[0148] (6) After washing with deionized water and ethanol in sequence, dry in a constant temperature drying oven at 110-150℃ for 2-24 hours to obtain amino-functionalized TiO2@SiO2@BaTiO3.

[0149] (7) The obtained powder is granulated and dry-pressed into shape;

[0150] (8) Granulation and Dry Pressing: First, a binder is added to the dried TiO2@SiO2@BT powder for granulation and sieving. After molding and debinding, the powder is sintered in air to obtain a highly stable BaTiO3-based dielectric material. The binder can be at least one of PVB, ethyl cellulose, and PVA, and the amount added can be 9 wt% of the total mass of the TiO2@SiO2@BT powder. After sintering, a high-strength, low-temperature co-fired material is finally obtained. The process parameters are listed in Table 1, and the performance test results of the final capacitor material are shown in Table 2.

[0151] Example 12

[0152] (1) Mix anhydrous ethanol, barium titanate, and glacial acetic acid in a mass ratio of 50:20:2. First, stir magnetically at 300 rpm for 40 min in a constant temperature environment of 40℃. Then, sonicate in a constant temperature environment of 40℃ for 40 min to obtain a mixed solution of surface-activated barium titanate.

[0153] (2) The obtained mixed solution of surface-activated barium titanate was placed in a water bath stirrer and heated to 40°C, and 3 wt% tetraethyl orthosilicate was added dropwise. After the mixed solution was continuously magnetically stirred in a constant temperature environment of 40°C for 1 hour, it was transferred to an ultrasonic device and sonicated for 40 minutes to obtain a mixed solution of tetraethyl orthosilicate-glacial acetic acid-barium titanate;

[0154] (3) Place the above solution in a water bath stirrer and heat it to 40°C. Add 60% ammonia water to adjust the pH to 9.5 so that glacial acetic acid and tetraethyl orthosilicate can fully react to generate SiO2 precipitate, which is then coated onto the surface of BaTiO3 powder under electrostatic action. After completing this process, maintain a constant temperature and continue to stir magnetically for 48 hours, and then dry at 150°C.

[0155] (4) The SiO2@BaTiO3 composite ceramic powder material was placed in a 2wt% di(2-hydroxypropionic acid)diammonium hydroxide titanium / ethanol solution. First, it was magnetically stirred at 100-300 rpm for 1-12 hours in a constant temperature environment of 30-60℃. Then, it was ultrasonicated at 100-300W for 1-12 hours in a constant temperature environment of 30-60℃.

[0156] (5) Place the SiO2@BaTiO3-di(2-hydroxypropionic acid)diammonium hydroxide titanium mixture 3 in a water bath stirrer and heat to 30-60℃. Add 60-100wt% ammonia water to adjust the pH to 9.5. Transfer the mixture to a reaction vessel and react at 120℃ for 4 hours. After naturally cooling to room temperature, separate the mixture. Weigh the product and dissolve it in isopropanol. Sonicate it until homogeneous. Add ammonia water to adjust the pH to 10. Sonicate for 5 minutes. Add 3-aminopropyltrimethoxysilane and sonicate until homogeneous. Reflux at 70℃ and 1000r / min for 12 hours.

[0157] (6) After washing with deionized water and ethanol in sequence, dry in a constant temperature drying oven at 110-150℃ for 2-24 hours to obtain amino-functionalized TiO2@SiO2@BaTiO3.

[0158] (7) The obtained powder is granulated and dry-pressed into shape;

[0159] (8) Granulation and Dry Pressing: First, a binder is added to the dried TiO2@SiO2@BT powder for granulation and sieving. After molding and debinding, the powder is sintered in air to obtain a highly stable BaTiO3-based dielectric material. The binder can be at least one of PVB, ethyl cellulose, and PVA, and the amount added can be 9 wt% of the total mass of the TiO2@SiO2@BT powder. After sintering, a high-strength, low-temperature co-fired material is finally obtained. The process parameters are listed in Table 1, and the performance test results of the final capacitor material are shown in Table 2.

[0160] Example 13

[0161] (1) Mix anhydrous ethanol, barium titanate, and glacial acetic acid in a mass ratio of 50:20:2. First, stir magnetically at 300 rpm for 40 min in a constant temperature environment of 40℃. Then, sonicate in a constant temperature environment of 40℃ for 40 min to obtain a mixed solution of surface-activated barium titanate.

[0162] (2) The obtained mixed solution of surface-activated barium titanate was placed in a water bath stirrer and heated to 40°C, and 6 wt% tetraethyl orthosilicate was added dropwise. After the mixed solution was continuously magnetically stirred in a constant temperature environment of 40°C for 1 hour, it was transferred to an ultrasonic device and sonicated for 40 minutes to obtain a mixed solution of tetraethyl orthosilicate-glacial acetic acid-barium titanate;

[0163] (3) Place the above solution in a water bath stirrer and heat it to 40°C. Add 60% ammonia water to adjust the pH to 9.5 so that glacial acetic acid and tetraethyl orthosilicate can fully react to generate SiO2 precipitate, which is then coated onto the surface of BaTiO3 powder under electrostatic action. After completing this process, maintain a constant temperature and continue to stir magnetically for 48 hours, and then dry at 150°C.

[0164] (4) The SiO2@BaTiO3 composite ceramic powder material was placed in a 2wt% di(2-hydroxypropionic acid)diammonium hydroxide titanium / ethanol solution. First, it was magnetically stirred at 100-300 rpm for 1-12 hours in a constant temperature environment of 30-60℃. Then, it was ultrasonicated at 100-300W for 1-12 hours in a constant temperature environment of 30-60℃.

[0165] (5) Place the SiO2@BaTiO3-di(2-hydroxypropionic acid)diammonium hydroxide titanium mixture 3 in a water bath stirrer and heat to 30-60℃. Add 60-100wt% ammonia water to adjust the pH to 9.5. Transfer the mixture to a reaction vessel and react at 120℃ for 4 hours. After naturally cooling to room temperature, separate the mixture. Weigh the product and dissolve it in isopropanol. Sonicate it until homogeneous. Add ammonia water to adjust the pH to 10. Sonicate for 5 minutes. Add 3-aminopropyltrimethoxysilane and sonicate until homogeneous. Reflux at 70℃ and 1000r / min for 12 hours.

[0166] (6) After washing with deionized water and ethanol in sequence, dry in a constant temperature drying oven at 110-150℃ for 2-24 hours to obtain amino-functionalized TiO2@SiO2@BaTiO3.

[0167] (7) The obtained powder is granulated and dry-pressed into shape;

[0168] (8) Granulation and Dry Pressing: First, a binder is added to the dried TiO2@SiO2@BT powder for granulation and sieving. After molding and debinding, the powder is sintered in air to obtain a highly stable BaTiO3-based dielectric material. The binder can be at least one of PVB, ethyl cellulose, and PVA, and the amount added can be 9 wt% of the total mass of the TiO2@SiO2@BT powder. After sintering, a high-strength, low-temperature co-fired material is finally obtained. The process parameters are listed in Table 1, and the performance test results of the final capacitor material are shown in Table 2.

[0169] Example 14

[0170] (1) Mix anhydrous ethanol, barium titanate, and glacial acetic acid in a mass ratio of 50:20:2. First, stir magnetically at 300 rpm for 40 min in a constant temperature environment of 40℃. Then, sonicate in a constant temperature environment of 40℃ for 40 min to obtain a mixed solution of surface-activated barium titanate.

[0171] (2) The obtained mixed solution of surface-activated barium titanate was placed in a water bath stirrer and heated to 40°C, and 10 wt% tetraethyl orthosilicate was added dropwise. After the mixed solution was continuously magnetically stirred in a constant temperature environment of 40°C for 1 hour, it was transferred to an ultrasonic device and sonicated for 40 minutes to obtain a mixed solution of tetraethyl orthosilicate-glacial acetic acid-barium titanate;

[0172] (3) Place the above solution in a water bath stirrer and heat it to 40°C. Add 60% ammonia water to adjust the pH to 9.5 so that glacial acetic acid and tetraethyl orthosilicate can fully react to generate SiO2 precipitate, which is then coated onto the surface of BaTiO3 powder under electrostatic action. After completing this process, maintain a constant temperature and continue to stir magnetically for 48 hours, and then dry at 150°C.

[0173] (4) The SiO2@BaTiO3 composite ceramic powder material was placed in a 2wt% di(2-hydroxypropionic acid)diammonium hydroxide titanium / ethanol solution. First, it was magnetically stirred at 100-300 rpm for 1-12 hours in a constant temperature environment of 30-60℃. Then, it was ultrasonicated at 100-300W for 1-12 hours in a constant temperature environment of 30-60℃.

[0174] (5) Place the SiO2@BaTiO3-di(2-hydroxypropionic acid)diammonium hydroxide titanium mixture 3 in a water bath stirrer and heat to 30-60℃. Add 60-100wt% ammonia water to adjust the pH to 9.5. Transfer the mixture to a reaction vessel and react at 120℃ for 4 hours. After naturally cooling to room temperature, separate the mixture. Weigh the product and dissolve it in isopropanol. Sonicate it until homogeneous. Add ammonia water to adjust the pH to 10. Sonicate for 5 minutes. Add 3-aminopropyltrimethoxysilane and sonicate until homogeneous. Reflux at 70℃ and 1000r / min for 12 hours.

[0175] (6) After washing with deionized water and ethanol in sequence, dry in a constant temperature drying oven at 110-150℃ for 2-24 hours to obtain amino-functionalized TiO2@SiO2@BaTiO3.

[0176] (7) The obtained powder is granulated and dry-pressed into shape;

[0177] (8) Granulation and Dry Pressing: First, a binder is added to the dried TiO2@SiO2@BT powder for granulation and sieving. After molding and debinding, the powder is sintered in air to obtain a highly stable BaTiO3-based dielectric material. The binder can be at least one of PVB, ethyl cellulose, and PVA, and the amount added can be 9 wt% of the total mass of the TiO2@SiO2@BT powder. After sintering, a high-strength, low-temperature co-fired material is finally obtained. The process parameters are listed in Table 1, and the performance test results of the final capacitor material are shown in Table 2.

[0178] Example 15

[0179] (1) Mix anhydrous ethanol, barium titanate, and glacial acetic acid in a mass ratio of 50:20:2. First, stir magnetically at 300 rpm for 40 min in a constant temperature environment of 40℃. Then, sonicate in a constant temperature environment of 40℃ for 40 min to obtain a mixed solution of surface-activated barium titanate.

[0180] (2) The obtained mixed solution of surface-activated barium titanate was placed in a water bath stirrer and heated to 40°C, and 15 wt% tetraethyl orthosilicate was added dropwise. After the mixed solution was continuously magnetically stirred in a constant temperature environment of 40°C for 1 hour, it was transferred to an ultrasonic device and sonicated for 40 min to obtain a mixed solution of tetraethyl orthosilicate-glacial acetic acid-barium titanate;

[0181] (3) Place the above solution in a water bath stirrer and heat it to 40°C. Add 60% ammonia water to adjust the pH to 9.5 so that glacial acetic acid and tetraethyl orthosilicate can fully react to generate SiO2 precipitate, which is then coated onto the surface of BaTiO3 powder under electrostatic action. After completing this process, maintain a constant temperature and continue to stir magnetically for 48 hours, and then dry at 150°C.

[0182] (4) The SiO2@BaTiO3 composite ceramic powder material was placed in a 2wt% di(2-hydroxypropionic acid)diammonium hydroxide titanium / ethanol solution. First, it was magnetically stirred at 100-300 rpm for 1-12 hours in a constant temperature environment of 30-60℃. Then, it was ultrasonicated at 100-300W for 1-12 hours in a constant temperature environment of 30-60℃.

[0183] (5) Place the SiO2@BaTiO3-di(2-hydroxypropionic acid)diammonium hydroxide titanium mixture 3 in a water bath stirrer and heat to 30-60℃. Add 60-100wt% ammonia water to adjust the pH to 9.5. Transfer the mixture to a reaction vessel and react at 120℃ for 4 hours. After naturally cooling to room temperature, separate the mixture. Weigh the product and dissolve it in isopropanol. Sonicate it until homogeneous. Add ammonia water to adjust the pH to 10. Sonicate for 5 minutes. Add 3-aminopropyltrimethoxysilane and sonicate until homogeneous. Reflux at 70℃ and 1000r / min for 12 hours.

[0184] (6) After washing with deionized water and ethanol in sequence, dry in a constant temperature drying oven at 110-150℃ for 2-24 hours to obtain amino-functionalized TiO2@SiO2@BaTiO3.

[0185] (7) The obtained powder is granulated and dry-pressed into shape;

[0186] (8) Granulation and Dry Pressing: First, a binder is added to the dried TiO2@SiO2@BT powder for granulation and sieving. After molding and debinding, the powder is sintered in air to obtain a highly stable BaTiO3-based dielectric material. The binder can be at least one of PVB, ethyl cellulose, and PVA, and the amount added can be 9 wt% of the total mass of the TiO2@SiO2@BT powder. After sintering, a high-strength, low-temperature co-fired material is finally obtained. The process parameters are listed in Table 1, and the performance test results of the final capacitor material are shown in Table 2.

[0187] Example 16

[0188] (1) Mix anhydrous ethanol, barium titanate, and glacial acetic acid in a mass ratio of 50:20:2. First, stir magnetically at 300 rpm for 40 min in a constant temperature environment of 40℃. Then, sonicate in a constant temperature environment of 40℃ for 40 min to obtain a mixed solution of surface-activated barium titanate.

[0189] (2) The obtained mixed solution of surface-activated barium titanate was placed in a water bath stirrer and heated to 40°C, and 1.5 wt% tetraethyl orthosilicate was added dropwise. After the mixed solution was continuously magnetically stirred in a constant temperature environment of 40°C for 1 hour, it was transferred to an ultrasonic device and sonicated for 40 minutes to obtain a mixed solution of tetraethyl orthosilicate-glacial acetic acid-barium titanate;

[0190] (3) Place the above solution in a water bath stirrer and heat it to 40°C. Add 60% ammonia water to adjust the pH to 9.5 so that glacial acetic acid and tetraethyl orthosilicate can fully react to generate SiO2 precipitate, which is then coated onto the surface of BaTiO3 powder under electrostatic action. After completing this process, maintain a constant temperature and continue to stir magnetically for 48 hours, and then dry at 150°C.

[0191] (4) The SiO2@BaTiO3 composite ceramic powder material was placed in a 4wt% di(2-hydroxypropionic acid)diammonium hydroxide titanium / ethanol solution. First, it was magnetically stirred at 100-300 rpm for 1-12 hours in a constant temperature environment of 30-60℃. Then, it was ultrasonicated at 100-300W for 1-12 hours in a constant temperature environment of 30-60℃.

[0192] (5) Place the SiO2@BaTiO3-di(2-hydroxypropionic acid)diammonium hydroxide titanium mixture 3 in a water bath stirrer and heat to 30-60℃. Add 60-100wt% ammonia water to adjust the pH to 9.5. Transfer the mixture to a reaction vessel and react at 120℃ for 4 hours. After naturally cooling to room temperature, separate the mixture. Weigh the product and dissolve it in isopropanol. Sonicate it until homogeneous. Add ammonia water to adjust the pH to 10. Sonicate for 5 minutes. Add 3-aminopropyltrimethoxysilane and sonicate until homogeneous. Reflux at 70℃ and 1000r / min for 12 hours.

[0193] (6) After washing with deionized water and ethanol in sequence, dry in a constant temperature drying oven at 110-150℃ for 2-24 hours to obtain amino-functionalized TiO2@SiO2@BaTiO3.

[0194] (7) The obtained powder is granulated and dry-pressed into shape;

[0195] (8) Granulation and Dry Pressing: First, a binder is added to the dried TiO2@SiO2@BT powder for granulation and sieving. After molding and debinding, the powder is sintered in air to obtain a highly stable BaTiO3-based dielectric material. The binder can be at least one of PVB, ethyl cellulose, and PVA, and the amount added can be 9 wt% of the total mass of the TiO2@SiO2@BT powder. After sintering, a high-strength, low-temperature co-fired material is finally obtained. The process parameters are listed in Table 1, and the performance test results of the final capacitor material are shown in Table 2.

[0196] Example 17

[0197] (1) Mix anhydrous ethanol, barium titanate, and glacial acetic acid in a mass ratio of 50:20:2. First, stir magnetically at 300 rpm for 40 min in a constant temperature environment of 40℃. Then, sonicate in a constant temperature environment of 40℃ for 40 min to obtain a mixed solution of surface-activated barium titanate.

[0198] (2) The obtained mixed solution of surface-activated barium titanate was placed in a water bath stirrer and heated to 40°C, and 3 wt% tetraethyl orthosilicate was added dropwise. After the mixed solution was continuously magnetically stirred in a constant temperature environment of 40°C for 1 hour, it was transferred to an ultrasonic device and sonicated for 40 minutes to obtain a mixed solution of tetraethyl orthosilicate-glacial acetic acid-barium titanate;

[0199] (3) Place the above solution in a water bath stirrer and heat it to 40°C. Add 60% ammonia water to adjust the pH to 9.5 so that glacial acetic acid and tetraethyl orthosilicate can fully react to generate SiO2 precipitate, which is then coated onto the surface of BaTiO3 powder under electrostatic action. After completing this process, maintain a constant temperature and continue to stir magnetically for 48 hours, and then dry at 150°C.

[0200] (4) The SiO2@BaTiO3 composite ceramic powder material was placed in a 4wt% di(2-hydroxypropionic acid)diammonium hydroxide titanium / ethanol solution. First, it was magnetically stirred at 100-300 rpm for 1-12 hours in a constant temperature environment of 30-60℃. Then, it was ultrasonicated at 100-300W for 1-12 hours in a constant temperature environment of 30-60℃.

[0201] (5) Place the SiO2@BaTiO3-di(2-hydroxypropionic acid)diammonium hydroxide titanium mixture 3 in a water bath stirrer and heat to 30-60℃. Add 60-100wt% ammonia water to adjust the pH to 9.5. Transfer the mixture to a reaction vessel and react at 120℃ for 4 hours. After naturally cooling to room temperature, separate the mixture. Weigh the product and dissolve it in isopropanol. Sonicate it until homogeneous. Add ammonia water to adjust the pH to 10. Sonicate for 5 minutes. Add 3-aminopropyltrimethoxysilane and sonicate until homogeneous. Reflux at 70℃ and 1000r / min for 12 hours.

[0202] (6) After washing with deionized water and ethanol in sequence, dry in a constant temperature drying oven at 110-150℃ for 2-24 hours to obtain amino-functionalized TiO2@SiO2@BaTiO3.

[0203] (7) The obtained powder is granulated and dry-pressed into shape;

[0204] (8) Granulation and Dry Pressing: First, a binder is added to the dried TiO2@SiO2@BT powder for granulation and sieving. After molding and debinding, the powder is sintered in air to obtain a highly stable BaTiO3-based dielectric material. The binder can be at least one of PVB, ethyl cellulose, and PVA, and the amount added can be 9 wt% of the total mass of the TiO2@SiO2@BT powder. After sintering, a high-strength, low-temperature co-fired material is finally obtained. The process parameters are listed in Table 1, and the performance test results of the final capacitor material are shown in Table 2.

[0205] Example 18

[0206] (1) Mix anhydrous ethanol, barium titanate, and glacial acetic acid in a mass ratio of 50:20:2. First, stir magnetically at 300 rpm for 40 min in a constant temperature environment of 40℃. Then, sonicate in a constant temperature environment of 40℃ for 40 min to obtain a mixed solution of surface-activated barium titanate.

[0207] (2) The obtained mixed solution of surface-activated barium titanate was placed in a water bath stirrer and heated to 40°C, and 6 wt% tetraethyl orthosilicate was added dropwise. After the mixed solution was continuously magnetically stirred in a constant temperature environment of 40°C for 1 hour, it was transferred to an ultrasonic device and sonicated for 40 minutes to obtain a mixed solution of tetraethyl orthosilicate-glacial acetic acid-barium titanate;

[0208] (3) Place the above solution in a water bath stirrer and heat it to 40°C. Add 60% ammonia water to adjust the pH to 9.5 so that glacial acetic acid and tetraethyl orthosilicate can fully react to generate SiO2 precipitate, which is then coated onto the surface of BaTiO3 powder under electrostatic action. After completing this process, maintain a constant temperature and continue to stir magnetically for 48 hours, and then dry at 150°C.

[0209] (4) The SiO2@BaTiO3 composite ceramic powder material was placed in a 4wt% di(2-hydroxypropionic acid)diammonium hydroxide titanium / ethanol solution. First, it was magnetically stirred at 100-300 rpm for 1-12 hours in a constant temperature environment of 30-60℃. Then, it was ultrasonicated at 100-300W for 1-12 hours in a constant temperature environment of 30-60℃.

[0210] (5) Place the SiO2@BaTiO3-di(2-hydroxypropionic acid)diammonium hydroxide titanium mixture 3 in a water bath stirrer and heat to 30-60℃. Add 60-100wt% ammonia water to adjust the pH to 9.5. Transfer the mixture to a reaction vessel and react at 120℃ for 4 hours. After naturally cooling to room temperature, separate the mixture. Weigh the product and dissolve it in isopropanol. Sonicate it until homogeneous. Add ammonia water to adjust the pH to 10. Sonicate for 5 minutes. Add 3-aminopropyltrimethoxysilane and sonicate until homogeneous. Reflux at 70℃ and 1000r / min for 12 hours.

[0211] (6) After washing with deionized water and ethanol in sequence, dry in a constant temperature drying oven at 110-150℃ for 2-24 hours to obtain amino-functionalized TiO2@SiO2@BaTiO3.

[0212] (7) The obtained powder is granulated and dry-pressed into shape;

[0213] (8) Granulation and Dry Pressing: First, a binder is added to the dried TiO2@SiO2@BT powder for granulation and sieving. After molding and debinding, the powder is sintered in air to obtain a highly stable BaTiO3-based dielectric material. The binder can be at least one of PVB, ethyl cellulose, and PVA, and the amount added can be 9 wt% of the total mass of the TiO2@SiO2@BT powder. After sintering, a high-strength, low-temperature co-fired material is finally obtained. The process parameters are listed in Table 1, and the performance test results of the final capacitor material are shown in Table 2.

[0214] Example 19

[0215] (1) Mix anhydrous ethanol, barium titanate, and glacial acetic acid in a mass ratio of 50:20:2. First, stir magnetically at 300 rpm for 40 min in a constant temperature environment of 40℃. Then, sonicate in a constant temperature environment of 40℃ for 40 min to obtain a mixed solution of surface-activated barium titanate.

[0216] (2) The obtained mixed solution of surface-activated barium titanate was placed in a water bath stirrer and heated to 40°C, and 10 wt% tetraethyl orthosilicate was added dropwise. After the mixed solution was continuously magnetically stirred in a constant temperature environment of 40°C for 1 hour, it was transferred to an ultrasonic device and sonicated for 40 minutes to obtain a mixed solution of tetraethyl orthosilicate-glacial acetic acid-barium titanate;

[0217] (3) Place the above solution in a water bath stirrer and heat it to 40°C. Add 60% ammonia water to adjust the pH to 9.5 so that glacial acetic acid and tetraethyl orthosilicate can fully react to generate SiO2 precipitate, which is then coated onto the surface of BaTiO3 powder under electrostatic action. After completing this process, maintain a constant temperature and continue to stir magnetically for 48 hours, and then dry at 150°C.

[0218] (4) The SiO2@BaTiO3 composite ceramic powder material was placed in a 4wt% di(2-hydroxypropionic acid)diammonium hydroxide titanium / ethanol solution. First, it was magnetically stirred at 100-300 rpm for 1-12 hours in a constant temperature environment of 30-60℃. Then, it was ultrasonicated at 100-300W for 1-12 hours in a constant temperature environment of 30-60℃.

[0219] (5) Place the SiO2@BaTiO3-di(2-hydroxypropionic acid)diammonium hydroxide titanium mixture 3 in a water bath stirrer and heat to 30-60℃. Add 60-100wt% ammonia water to adjust the pH to 9.5. Transfer the mixture to a reaction vessel and react at 120℃ for 4 hours. After naturally cooling to room temperature, separate the mixture. Weigh the product and dissolve it in isopropanol. Sonicate it until homogeneous. Add ammonia water to adjust the pH to 10. Sonicate for 5 minutes. Add 3-aminopropyltrimethoxysilane and sonicate until homogeneous. Reflux at 70℃ and 1000r / min for 12 hours.

[0220] (6) After washing with deionized water and ethanol in sequence, dry in a constant temperature drying oven at 110-150℃ for 2-24 hours to obtain amino-functionalized TiO2@SiO2@BaTiO3.

[0221] (7) The obtained powder is granulated and dry-pressed into shape;

[0222] (8) Granulation and Dry Pressing: First, a binder is added to the dried TiO2@SiO2@BT powder for granulation and sieving. After molding and debinding, the powder is sintered in air to obtain a highly stable BaTiO3-based dielectric material. The binder can be at least one of PVB, ethyl cellulose, and PVA, and the amount added can be 9 wt% of the total mass of the TiO2@SiO2@BT powder. After sintering, a high-strength, low-temperature co-fired material is finally obtained. The process parameters are listed in Table 1, and the performance test results of the final capacitor material are shown in Table 2.

[0223] Example 20

[0224] (1) Mix anhydrous ethanol, barium titanate, and glacial acetic acid in a mass ratio of 50:20:2. First, stir magnetically at 300 rpm for 40 min in a constant temperature environment of 40℃. Then, sonicate in a constant temperature environment of 40℃ for 40 min to obtain a mixed solution of surface-activated barium titanate.

[0225] (2) The obtained mixed solution of surface-activated barium titanate was placed in a water bath stirrer and heated to 40°C, and 15 wt% tetraethyl orthosilicate was added dropwise. After the mixed solution was continuously magnetically stirred in a constant temperature environment of 40°C for 1 hour, it was transferred to an ultrasonic device and sonicated for 40 min to obtain a mixed solution of tetraethyl orthosilicate-glacial acetic acid-barium titanate;

[0226] (3) Place the above solution in a water bath stirrer and heat it to 40°C. Add 60% ammonia water to adjust the pH to 9.5 so that glacial acetic acid and tetraethyl orthosilicate can fully react to generate SiO2 precipitate, which is then coated onto the surface of BaTiO3 powder under electrostatic action. After completing this process, maintain a constant temperature and continue to stir magnetically for 48 hours, and then dry at 150°C.

[0227] (4) The SiO2@BaTiO3 composite ceramic powder material was placed in a 4wt% di(2-hydroxypropionic acid)diammonium hydroxide titanium / ethanol solution. First, it was magnetically stirred at 100-300 rpm for 1-12 hours in a constant temperature environment of 30-60℃. Then, it was ultrasonicated at 100-300W for 1-12 hours in a constant temperature environment of 30-60℃.

[0228] (5) Place the SiO2@BaTiO3-di(2-hydroxypropionic acid)diammonium hydroxide titanium mixture 3 in a water bath stirrer and heat to 30-60℃. Add 60-100wt% ammonia water to adjust the pH to 9.5. Transfer the mixture to a reaction vessel and react at 120℃ for 4 hours. After naturally cooling to room temperature, separate the mixture. Weigh the product and dissolve it in isopropanol. Sonicate it until homogeneous. Add ammonia water to adjust the pH to 10. Sonicate for 5 minutes. Add 3-aminopropyltrimethoxysilane and sonicate until homogeneous. Reflux at 70℃ and 1000r / min for 12 hours.

[0229] (6) After washing with deionized water and ethanol in sequence, dry in a constant temperature drying oven at 110-150℃ for 2-24 hours to obtain amino-functionalized TiO2@SiO2@BaTiO3.

[0230] (7) The obtained powder is granulated and dry-pressed into shape;

[0231] (8) Granulation and Dry Pressing: First, a binder is added to the dried TiO2@SiO2@BT powder for granulation and sieving. After molding and debinding, the powder is sintered in air to obtain a highly stable BaTiO3-based dielectric material. The binder can be at least one of PVB, ethyl cellulose, and PVA, and the amount added can be 9 wt% of the total mass of the TiO2@SiO2@BT powder. After sintering, a high-strength, low-temperature co-fired material is finally obtained. The process parameters are listed in Table 1, and the performance test results of the final capacitor material are shown in Table 2.

[0232] Example 21

[0233] (1) Mix anhydrous ethanol, barium titanate, and glacial acetic acid in a mass ratio of 50:20:1. First, stir magnetically at 300 rpm for 40 min in a constant temperature environment of 40℃. Then, sonicate in a constant temperature environment of 40℃ for 40 min to obtain a mixed solution of surface-activated barium titanate.

[0234] (2) The obtained mixed solution of surface-activated barium titanate was placed in a water bath stirrer and heated to 40°C, and 15 wt% tetraethyl orthosilicate was added dropwise. After the mixed solution was continuously magnetically stirred in a constant temperature environment of 40°C for 1 hour, it was transferred to an ultrasonic device and sonicated for 40 min to obtain a mixed solution of tetraethyl orthosilicate-glacial acetic acid-barium titanate;

[0235] (3) Place the above solution in a water bath stirrer and heat it to 40°C. Add 60% ammonia water to adjust the pH to 9.5 so that glacial acetic acid and tetraethyl orthosilicate can fully react to generate SiO2 precipitate, which is then coated onto the surface of BaTiO3 powder under electrostatic action. After completing this process, maintain a constant temperature and continue to stir magnetically for 48 hours, and then dry at 150°C.

[0236] (4) The SiO2@BaTiO3 composite ceramic powder material was placed in a 6wt% solution of di(2-hydroxypropionic acid)diammonium hydroxide titanium / ethanol. First, it was magnetically stirred at 100-300 rpm for 1-12 hours in a constant temperature environment of 30-60℃. Then, it was ultrasonicated at 100-300W for 1-12 hours in a constant temperature environment of 30-60℃.

[0237] (5) Place the SiO2@BaTiO3-di(2-hydroxypropionic acid)diammonium hydroxide titanium mixture 3 in a water bath stirrer and heat to 30-60℃. Add 60-100wt% ammonia water to adjust the pH to 9.5. Transfer the mixture to a reaction vessel and react at 120℃ for 4 hours. After naturally cooling to room temperature, separate the mixture. Weigh the product and dissolve it in isopropanol. Sonicate it until homogeneous. Add ammonia water to adjust the pH to 10. Sonicate for 5 minutes. Add 3-aminopropyltrimethoxysilane and sonicate until homogeneous. Reflux at 70℃ and 1000r / min for 12 hours.

[0238] (6) After washing with deionized water and ethanol in sequence, dry in a constant temperature drying oven at 110-150℃ for 2-24 hours to obtain amino-functionalized TiO2@SiO2@BaTiO3.

[0239] (7) The obtained powder is granulated and dry-pressed into shape;

[0240] (8) Granulation and Dry Pressing: First, a binder is added to the dried TiO2@SiO2@BT powder for granulation and sieving. After molding and debinding, the powder is sintered in air to obtain a highly stable BaTiO3-based dielectric material. The binder can be at least one of PVB, ethyl cellulose, and PVA, and the amount added can be 9 wt% of the total mass of the TiO2@SiO2@BT powder. After sintering, a high-strength, low-temperature co-fired material is finally obtained. The process parameters are listed in Table 1, and the performance test results of the final capacitor material are shown in Table 2.

[0241] Comparative Example 1

[0242] The preparation process of the TiO2@SiO2@BaTiO3 composite ceramic powder material with low expansion, low dielectric constant, low dielectric loss, and high strength in Comparative Example 1 is the same as in Example 1, except that the excess glacial acetic acid is 25 ml. The process parameters are listed in Table 2, and the final performance test results of the material are shown in Table 2.

[0243] Comparative Example 2

[0244] The preparation process of the TiO2@SiO2@BaTiO3 composite ceramic powder material with low expansion, low dielectric constant, low dielectric loss, and high strength in Comparative Example 2 is the same as in Example 1, except that the excess tetraethyl orthosilicate is 20 wt%. The process parameters are listed in Table 2, and the final performance test results of the material are shown in Table 2.

[0245] Comparative Example 3

[0246] The preparation process of the TiO2@SiO2@BaTiO3 composite ceramic powder material with low expansion, low dielectric constant, low dielectric loss, and high strength in Comparative Example 3 is the same as in Example 1, except that the excess of bis(2-hydroxypropionic acid)diammonium hydroxide titanium is 8wt%. The process parameters are listed in Table 2, and the final performance test results of the material are shown in Table 2.

[0247] Comparative Example 4

[0248] The preparation process of the TiO2@SiO2@BaTiO3 composite ceramic powder material with low expansion, low dielectric constant, low dielectric loss and high strength in Comparative Example 4 is the same as in Example 1, except that: the titanium di(2-hydroxypropionic acid)diammonium hydroxide is 0 wt%.

[0249] Table 1 shows the raw material composition and experimental parameters of high-strength ceramic capacitor materials:

[0250]

[0251]

[0252] Table 2 shows the performance of high-strength ceramic capacitor materials:

[0253]

[0254]

Claims

1. A TiO2@SiO2@BaTiO3 composite ceramic powder material, characterized in that, include: The composite ceramic powder consists of a BaTiO3 ceramic powder core, and sequentially coated with a SiO2 layer and a TiO2 layer. The SiO2 layer and TiO2 layer are both SiO2 phases. The mass content of the SiO2 phase in the TiO2@SiO2@BaTiO3 composite ceramic powder material is 0.5–5%, and the mass content of the TiO2 phase is 0.3–1.5%. The SiO2 layer has a thickness of 10–50 nm and is prepared using tetraethyl orthosilicate as a raw material. The TiO2 layer has a thickness of 10–30 nm and is synthesized using bis(2-hydroxypropionic acid)diammonium hydroxide titanium alloy as a precursor, ammonium lactate as a polyelectrolyte, and pH adjustment of the solution to form an anatase TiO2 shell. The dielectric constant of the TiO2@SiO2@BaTiO3 composite ceramic powder material was measured to be 2500–3500 at 1 MHz, and the dielectric loss was less than 2.5 × 10⁻⁶. -2 .

2. The TiO2@SiO2@BaTiO3 composite ceramic powder material according to claim 1, characterized in that, The particle size of the BaTiO3 ceramic powder is 100–900 nm.

3. A method for preparing the TiO2@SiO2@BaTiO3 composite ceramic powder material according to claim 1 or 2, characterized in that, include: (1) BaTiO3 powder is mixed with at least one acid solution selected from glacial acetic acid solution, nitric acid solution and hydrochloric acid solution to improve the ionic surface charge of BaTiO3 powder and obtain surface-activated barium titanate mixed solution 1; (2) Mix the surface-activated barium titanate mixed solution 1 with tetraethyl orthosilicate (TEOS) to obtain a tetraethyl orthosilicate-acid-barium titanate mixed solution 2; (3) Ammonia water was added dropwise to a mixed solution 2 of tetraethyl orthosilicate-acid-barium titanate. By adjusting the pH and under electrostatic action, SiO2@BaTiO3 composite ceramic powder material was prepared. (4) The obtained SiO2@BaTiO3 composite ceramic powder material was added to the di(2-hydroxypropionic acid)diammonium hydroxide titanium solution and mixed to obtain mixed solution 3; (5) Ammonia water was added dropwise to mixed solution 3, and TiO2@SiO2@BaTiO3 composite ceramic powder material was prepared by adjusting the pH and under electrostatic action.

4. The preparation method according to claim 3, characterized in that, In step (1), the solvent of the acid solution is selected from at least one of ethanol, diethylene glycol monomethyl ether, propylene glycol methyl ether, and dipropylene glycol dimethyl ether; the concentration of the glacial acetic acid solution, nitric acid solution, and hydrochloric acid solution is 1-10 wt%. BaTiO3 powder was placed in a 1-10 wt% glacial acetic acid / ethanol solution and first magnetically stirred at 100-300 rpm for 1-12 hours in a constant temperature environment of 30-60℃. Then, it was sonicated at 100-300 W for 1-12 hours in a constant temperature environment of 30-60℃. After filtration and drying, surface-activated barium titanate powder was obtained. The total amount of glacial acetic acid in the glacial acetic acid solution does not exceed 20 wt% of the BaTiO3 powder mass, and the drying temperature is 120°C.

5. The preparation method according to claim 3, characterized in that, In step (2), the mixed solution 1 of surface-activated barium titanate is placed in a water bath stirrer and heated to 30-60°C, and 1-20 wt% of tetraethyl orthosilicate is added dropwise; then, after being magnetically stirred at 100-300 rpm for 1-12 hours in a constant temperature environment of 30-60°C, it is transferred to an ultrasonic device and sonicated at 100-300W for 1-12 hours to obtain a mixed solution 2 of tetraethyl orthosilicate-acid-barium titanate; The total amount of tetraethyl orthosilicate does not exceed 15 wt% of the BaTiO3 powder; the purity of the tetraethyl orthosilicate is analytical grade.

6. The preparation method according to claim 3, characterized in that, In step (3), the mixed solution 2 of tetraethyl orthosilicate-acid-barium titanate is placed in a water bath stirrer and heated to 30-60°C. 60-100wt% ammonia water is added dropwise to adjust the pH to 9-11 so that the acid solution reacts fully with tetraethyl orthosilicate to generate SiO2 precipitate. Under the action of electrostatics, the SiO2 layer is coated onto the surface of BaTiO3 powder. After this process is completed, the constant temperature is maintained and the magnetic stirring is continued for 2-48 hours. The concentration of the ammonia water is 24wt% to 28wt%.

7. The preparation method according to claim 3, characterized in that, In step (4), the concentration of the di(2-hydroxypropionic acid)diammonium hydroxide titanium solution is 20-30 wt%. The SiO2@BaTiO3 composite ceramic powder was placed in a 20-30 wt% solution of di(2-hydroxypropionic acid)diammonium hydroxide titanium / ethanol. It was first magnetically stirred at 100-300 rpm for 1-12 hours in a constant temperature environment of 30-60℃, and then sonicated at 100-300 W for 1-12 hours in a constant temperature environment of 30-60℃. The total amount of bis(2-hydroxypropionic acid) diammonium hydroxide titanium in the solution does not exceed 30 wt% of the mass of BaTiO3 powder.

8. The preparation method according to claim 3, characterized in that, In step (5), the SiO2@BaTiO3-bis(2-hydroxypropionic acid)diammonium hydroxide titanium mixed solution 3 is placed in a water bath stirrer and heated to 30-60℃. 60-100wt% ammonia water is added dropwise to adjust the pH to 9-11. The mixture is then transferred to a reaction vessel and reacted at 120-160℃ for 2-10 h. After natural cooling to room temperature, TiO2@SiO2@BaTiO3 composite ceramic powder material is prepared.

9. The preparation method according to any one of claims 3-8, characterized in that, TiO2@SiO2@BaTiO3 composite ceramic powder was dissolved in isopropanol and ultrasonically treated. Ammonia was then added to adjust the pH to 10-12, and ultrasonic treatment was continued. 3-aminopropyltrimethoxysilane was then added dropwise and ultrasonically homogenized. The mixture was refluxed at 30-60℃ and 200-300 r / min for 1-2 h. Finally, it was washed sequentially with deionized water and ethanol and dried in a constant temperature drying oven at 110-150℃ for 2-24 hours to obtain amino-functionalized TiO2@SiO2@BaTiO3.

10. A high-temperature stable barium titanate composite ceramic capacitor material, characterized in that, The TiO2@SiO2@BaTiO3 composite ceramic powder material described in claim 1 or 2 is granulated and pressed into sheets, and then sintered at 1150-1350℃ for 1-4 hours to obtain a high-temperature stable barium titanate composite ceramic capacitor material.

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