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CN-115565781-B - TiO (titanium dioxide)2@SiO2@BaTiO3Composite ceramic powder material and preparation method and application thereof

CN115565781BCN 115565781 BCN115565781 BCN 115565781BCN-115565781-B

Abstract

The invention relates to a TiO 2 @SiO 2 @BaTiO 3 composite ceramic powder material, a preparation method and application thereof. The TiO 2 @SiO 2 @BaTiO 3 composite ceramic powder material comprises BaTiO 3 ceramic powder serving as an inner core, and a SiO 2 layer and a TiO 2 layer which are sequentially coated on the surface of the BaTiO 3 ceramic powder, wherein the SiO 2 layer comprises a SiO 2 phase, the TiO 2 layer comprises a TiO 2 phase, the mass content of the SiO 2 phase in the TiO 2 @SiO 2 @BaTiO 3 composite ceramic powder material is 0.5-5%, and the content of the TiO 2 phase is 0.3-1.5%.

Inventors

  • XIE TIANYI
  • WANG HUAIZHI
  • LIN HUIXING
  • REN HAISHEN
  • ZHAO XIANGYU
  • HE FEI
  • JIANG SHAOHU
  • ZHANG YI
  • GU ZHONGYUAN

Assignees

  • 中国科学院上海硅酸盐研究所

Dates

Publication Date
20260512
Application Date
20220720

Claims (10)

  1. 1. A TiO 2 @SiO 2 @BaTiO 3 composite ceramic powder material is characterized by comprising BaTiO 3 ceramic powder serving as an inner core, a SiO 2 layer and a TiO 2 layer which are sequentially coated on the surface of the BaTiO 3 ceramic powder, wherein the SiO 2 layer is in SiO 2 phase, the TiO 2 layer is in TiO 2 phase, the mass content of the SiO 2 phase in the TiO 2 @SiO 2 @BaTiO 3 composite ceramic powder material is 0.5-5%, the mass content of the TiO 2 phase is 0.3-1.5%, the thickness of the SiO 2 layer is 10-50 nm, the TiO 2 layer is prepared by taking tetraethoxysilane as a raw material, the thickness of the TiO 2 layer is 10-30 nm, the ammonium lactate is taken as a precursor, the pH of a solution is regulated, the anatase type TiO 2 shell layer is synthesized, and the dielectric constant of the TiO 2 @SiO 2 @BaTiO 3 composite ceramic powder material is 2500-3500, and the dielectric loss is lower than 2.5X10. 10 -2 under the condition of 1 MHz.
  2. 2. The TiO 2 @SiO 2 @BaTiO 3 composite ceramic powder material according to claim 1, wherein the particle size of the BaTiO 3 ceramic powder is 100 to 900 nm.
  3. 3. A method for preparing the TiO 2 @SiO 2 @BaTiO 3 composite ceramic powder material according to claim 1 or 2, comprising: (1) Mixing at least one acid solution of glacial acetic acid solution, nitric acid solution and hydrochloric acid solution with BaTiO 3 powder to improve the surface charge of BaTiO 3 powder ions and obtain a mixed solution 1 of surface-activated barium titanate; (2) Mixing the mixed solution 1 of the surface-activated barium titanate with Tetraethoxysilane (TEOS) to obtain a mixed solution 2 of tetraethoxysilane-acid-barium titanate; (3) Dropwise adding ammonia water into the mixed solution 2 of tetraethoxysilane-acid-barium titanate, and preparing the SiO 2 @BaTiO 3 composite ceramic powder material under the action of static electricity by adjusting the pH value; (4) Adding the obtained SiO 2 @BaTiO 3 composite ceramic powder material into a di (2-hydroxy propionic acid) diammonium hydroxide titanium solution and mixing to obtain a mixed solution 3; (5) And (3) dropwise adding ammonia water into the mixed solution 3, and preparing the TiO 2 @SiO 2 @BaTiO 3 composite ceramic powder material under the electrostatic action by regulating the pH.
  4. 4. The preparation method of claim 3, wherein in the 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, and the concentration of the glacial acetic acid solution, the nitric acid solution and the hydrochloric acid solution is 1-10wt%; Placing BaTiO 3 powder in glacial acetic acid/ethanol solution with the concentration of 1-10wt%, magnetically stirring for 1-12 hours at 100-300 r/min in a constant temperature environment with the concentration of 30-60 ℃, then performing ultrasonic treatment for 1-12 hours at 100-300W in the constant temperature environment with the temperature of 30-60 ℃, and performing suction filtration and drying to obtain surface-activated barium titanate powder; The total amount of glacial acetic acid in the glacial acetic acid solution is not more than 20 weight percent of the mass of BaTiO 3 powder, and the drying temperature is 120 ℃.
  5. 5. The preparation method of the barium titanate powder according to claim 3, wherein in the step (2), the mixed solution 1 of the surface-activated barium titanate is placed in a water bath stirrer to be stirred and heated to 30-60 ℃, and 1-20wt% of ethyl orthosilicate is added dropwise, and after the mixture is magnetically stirred for 1-12 hours in a constant temperature environment of 30-60 ℃ at a rotating speed of 100-300 r/min, the mixture is transferred into an ultrasonic device to be subjected to ultrasonic treatment for 1-12 hours at 100-300 w to obtain the mixed solution 2 of the ethyl orthosilicate-acid-barium titanate; The total amount of the ethyl orthosilicate is not more than 15wt% of the mass of the BaTiO 3 powder, and the purity of the ethyl orthosilicate is analytically pure.
  6. 6. The preparation method of claim 3, wherein in the step (3), the mixed solution 2 of tetraethoxysilane-acid-barium titanate is placed in a water bath stirrer to be stirred and heated to 30-60 ℃, 60-100 wt% of ammonia water is added dropwise to adjust the pH to 9-11, so that an acid solution and tetraethoxysilane fully react to generate SiO 2 precipitate, and the SiO 2 layer is coated on the surface of BaTiO 3 powder under the action of static electricity, and the constant temperature is kept for continuous magnetic stirring for 2-48 hours after the process is completed; The concentration of the ammonia water is 24-28 wt%.
  7. 7. The method according to claim 3, wherein in the step (4), the concentration of the titanium bis (2-hydroxypropionate) diammonium hydroxide solution is 20-30wt%; Placing the SiO 2 @BaTiO 3 composite ceramic powder material into a bis (2-hydroxypropionic acid) diammonium hydroxide titanium/ethanol solution with the concentration of 20-30wt%, magnetically stirring for 1-12 hours at 100-300 r/min in a constant temperature environment at 30-60 ℃, and then performing ultrasonic treatment for 1-12 hours at 100-300W in the constant temperature environment at 30-60 ℃; the total amount of the di (2-hydroxy propionic acid) diammonium hydroxide titanium in the di (2-hydroxy propionic acid) diammonium hydroxide titanium solution is not more than 30wt% of the mass of the BaTiO 3 powder.
  8. 8. The preparation method of claim 3, wherein in the step (5), the SiO 2 @BaTiO 3 -bis (2-hydroxy propionic acid) diammonium hydroxide titanium mixed solution 3 is placed in a water bath stirrer, stirred and heated to 30-60 ℃, 60-100 wt% ammonia water is added dropwise to adjust the pH to 9-11, the mixed solution is moved into a reaction kettle, reacted for 2-10 hours at 120-160 ℃, and then naturally cooled to room temperature, so that the TiO 2 @SiO 2 @BaTiO 3 composite ceramic powder material is prepared.
  9. 9. The preparation method according to any one of claims 3 to 8, wherein the TiO 2 @SiO 2 @BaTiO 3 composite ceramic powder material is dissolved in isopropanol and subjected to ultrasonic treatment, then ammonia water is added to adjust the pH to 10 to 12, ultrasonic treatment is continued, 3-aminopropyl trimethoxysilane is added dropwise and subjected to ultrasonic homogenization, reflux reaction is carried out for 1 to 2 hours at 30 to 60 ℃ and 200 to 300r/min, and finally deionized water and ethanol are sequentially washed and then put into an oven at a constant temperature of 110 to 150 ℃ for 2 to 24 hours, and then the amino-functionalized TiO 2 @SiO 2 @BaTiO 3 is obtained.
  10. 10. The high-temperature stable barium titanate composite ceramic capacitor material is characterized in that the TiO 2 @SiO 2 @BaTiO 3 composite ceramic powder material in claim 1 or 2 is subjected to granulation and tabletting molding, and then sintered for 1-4 hours at 1150-1350 ℃ to obtain the high-temperature stable barium titanate composite ceramic capacitor material.

Description

TiO 2@SiO2@BaTiO3 composite ceramic powder material and preparation method and application thereof Technical Field The invention relates to a composite ceramic capacitor material, in particular to a TiO 2@SiO2@BaTiO3 composite ceramic powder material with high dielectric constant, low dielectric loss and stable dielectric temperature change rate, and a preparation method and application thereof, belonging to the field of chip ceramic capacitor materials. Background The multilayer ceramic capacitor (mLCC) is formed by laminating ceramic dielectric films printed with electrodes (inner electrodes) in a staggered mode, forming a ceramic chip through one-time high-temperature sintering, and sealing metal layers (outer electrodes) at two ends of the chip, thereby forming a monolithic-like structure. In recent years, the capacitor is used as one of three passive components and is widely applied to the fields of national defense technology, aerospace, electric automobiles, electronic equipment, wireless communication, chemical and biological medical treatment, environmental energy and the like. In order to meet the requirements of application in certain specific fields or extreme application environments, ceramic capacitors are rapidly developed towards high energy storage and wide temperature ranges. mLCC is classified according to the temperature characteristics of the ceramic dielectric material and can be generally classified into two types, a type I ceramic dielectric and a type II ceramic dielectric. The first type of ceramic capacitor is generally simple oxide or titanate, and has a small capacity, and the second type of ceramic capacitor represented by BaTiO 3 has a high dielectric constant and low loss. At present, the application environment requires that the ceramic capacitor has a relatively stable medium temperature change rate (namely delta C/C25< 15%) at-55 ℃ to 150 ℃, but barium titanate can generate crystal structure transition along with temperature change, so that spontaneous polarization is generated. Near the curie temperature (about 128 ℃) the dielectric constant of barium titanate may be abrupt, greatly affecting the use of barium titanate as mLCC. In most of the studies on BaTiO 3, doping with the addition of certain inorganic oxides is generally used to improve the dielectric properties thereof, but it is difficult to shift the curie peak near 22 ℃ with the addition of a small amount of inorganic oxide. Furthermore, doping oxide in BaTiO 3 is very likely to cause abnormal growth of crystal grains, which is unfavorable for barium titanate to maintain a high dielectric constant, resulting in a decrease in energy storage. Disclosure of Invention Aiming at the defects of unstable medium temperature change rate and easy abnormal growth of crystal grains of barium titanate, the invention aims to provide a barium titanate-based ceramic composite material with excellent high-temperature stability prepared by sol-gel and a preparation method thereof. BaTiO 3 -based mLCC material with dielectric constant of 2500-3500, dielectric temperature change rate of less than 15%, low cost and easy mass production, a preparation method thereof and a capacitor prepared from the composite material. On one hand, the invention provides a TiO 2@SiO2@BaTiO3 composite ceramic powder material, which comprises BaTiO 3 ceramic powder serving as an inner core and a SiO 2 layer coated on the surface of the BaTiO 3 ceramic powder, wherein the SiO 2 layer is composed of a SiO 2 phase, and the mass content of the SiO 2 phase in the SiO 2@BaTiO3 composite ceramic powder material is 0.5-5%. Preferably, the mass content of the TiO 2 phase in the TiO 2@SiO2@BaTiO3 composite ceramic powder material is 0.3-1.5%, preferably 0.3-1 wt%, more preferably 0.5-1 wt%. Preferably, the granularity of the BaTiO 3 ceramic powder is 100-900 nm. Preferably, the thickness of the SiO 2 layer is 10-50 nm, and the SiO 2 layer is prepared by using ethyl orthosilicate as a raw material. Preferably, the thickness of the TiO 2 layer is 10-30 nm, and the TiO 2 layer is prepared by taking a di (2-hydroxy propionic acid) diammonium hydroxide titanium compound solution as a raw material (specifically, the di (2-hydroxy propionic acid) diammonium hydroxide titanium compound is taken as a precursor, ammonium lactate is taken as polyelectrolyte, and the pH value of the solution is regulated to synthesize an anatase type TiO 2 shell layer). Preferably, the dielectric constant of the TiO 2@SiO2@BaTiO3 composite ceramic powder material is 2500-3500, and the dielectric loss is lower than 2.5X10- -2 (1 MHz). On the other hand, the invention provides a preparation method of the TiO 2@SiO2@BaTiO3 composite ceramic powder material, which comprises the following steps: (1) Mixing at least one acid solution of glacial acetic acid solution, nitric acid solution and hydrochloric acid solution with BaTiO 3 powder to improve the surface charge of BaTiO 3 powder ions and obt