Silver niobate-based antiferroelectric energy storage ceramic with high energy storage characteristic and low-temperature sintering method thereof
阅读说明：本技术 一种高储能特性铌酸银基反铁电储能陶瓷及其低温烧结方法 (Silver niobate-based antiferroelectric energy storage ceramic with high energy storage characteristic and low-temperature sintering method thereof ) 是由 徐永豪 杨振东 田晶晶 田恒 于 2021-10-13 设计创作，主要内容包括：本发明涉及高储能特性铌酸银基反铁电储能陶瓷及其低温烧结方法,可有效解决现有技术击穿场强低、制备工艺复杂、反铁电相不稳定的问题,其解决的技术方案是,本发明以组分(1-x)AgNbO3-x(Sr-(0.7)Bi-(0.2))HfO-(3)-0.01BCB为基础,采用传统的固相反应法,将高纯的Ag-(2)O粉体、Nb-(2)O-(5)粉体、SrCO-(3)粉体、Bi-(2)O-(3)粉体和HfO-(2)粉体作为基体材料；以Ba(OH)-(2)·8H-(2)O粉体、H-(3)BO-(3)粉体和CuO粉体按摩尔比1:2:1制备而成的BaCu(B-(2)O-(7))作为烧结助剂制备而成,本发明在保证高储能特性的前提下,简化铌酸银基反铁电储能陶瓷的制备工艺,制备出高储能密度,高储能效率并具有良好温度稳定性的铌酸银基反铁电储能陶瓷,是铌酸银基反铁电储能陶瓷制备方法上的创新。(The invention relates to silver niobate-based antiferroelectric energy storage ceramic with high energy storage characteristic and a low-temperature sintering method thereof, which can effectively solve the problems of low breakdown field strength, complex preparation process and unstable antiferroelectric phase in the prior art and adopts the technical scheme that the silver niobate-based antiferroelectric energy storage ceramic is prepared from (1- x )AgNbO3‑ x (Sr 0.7 Bi 0.2 )HfO 3 Based on-0.01 BCB, adopting traditional solid phase reaction method to prepare high-purity Ag 2 O powder and Nb 2 O 5 Powder and SrCO 3 Powder of Bi 2 O 3 Powder and HfO 2 The powder is used as a base material; with Ba (OH) 2 ·8H 2 O powder and H 3 BO 3 BaCu (B) prepared by powder and CuO powder according to the mol ratio of 1:2:1 2 O 7 ) As a sintering aidOn the premise of ensuring high energy storage characteristics, the invention simplifies the preparation process of the silver niobate-based antiferroelectric energy storage ceramic, prepares the silver niobate-based antiferroelectric energy storage ceramic with high energy storage density, high energy storage efficiency and good temperature stability, and is an innovation in the preparation method of the silver niobate-based antiferroelectric energy storage ceramic.)
1. The silver niobate-based antiferroelectric energy storage ceramic with high energy storage characteristic is characterized by comprising the following components (1-x) AgNbO3-x (Sr)0.7Bi0.2)HfO3Based on-0.01 BCB, adopting traditional solid phase reaction method to prepare high-purity Ag2O powder and Nb2O5Powder and SrCO3Powder of Bi2O3Powder and HfO2The powder is used as a base material; with Ba (OH)2·8H2O powder and H3BO3BaCu (B) prepared by powder and CuO powder according to the mol ratio of 1:2:12O7) And granulating and pressing as a sintering aid.
2. The low-temperature sintering method of silver niobate-based antiferroelectric energy storage ceramic with high energy storage characteristics as claimed in claim 1, which is characterized by comprising the following steps:
1) the mass of each raw material is calculated according to the molar ratio of 0 to 0.02 to 0.04 to 0.05 to 0.055 to 0.06, and Ag is weighed respectively2O powder and Nb2O5Powder and SrCO3Powder of Bi2O3Powder and HfO2Powder;
2) firstly, the Ag weighed in the step 1) is weighed2O powder and Nb2O5Powder and SrCO3Powder of Bi2O3Powder and HfO2Mixing and ball-milling the powder to form first matrix powder;
3) sequentially drying, calcining and cooling the matrix powder obtained in the step 2) to obtain first prefabricated matrix powder;
4) calculating and weighing Ba (OH) according to the molar ratio of 1:2:12·8H2O powder and H3BO3Powder and CuO powder;
5) firstly, weighing Ba (OH) in the step 4)2·8H2O powder and H3BO3Mixing the powder and the CuO powder and performing ball milling to form second matrix powder;
6) drying, calcining and cooling the second matrix powder obtained in the step 5) in sequence to obtain prefabricated BCB powder;
7) performing secondary ball milling and drying on the first prefabricated base powder obtained in the step 3), mixing the first prefabricated base powder with the prefabricated BCB powder obtained in the step 6), continuously performing ball milling, and performing ball milling and drying treatment in sequence to obtain prefabricated mixed dry powder;
8) preparing PVA solution, and adding the prepared PVA solution into the prepared mixed dry powder obtained in the step 7) for granulation to form powder particles; sieving the prepared powder particles, and removing large powder particles and small powder particles; finally pressing the powder particles obtained after sieving into a blank;
9) and (3) sequentially carrying out glue discharging, cooling, natural cooling, cold isostatic pressing and calcining on the blank obtained in the step 8) to obtain the silver niobate-based antiferroelectric energy storage ceramic taking BCB as the sintering aid.
3. The method for low-temperature sintering of silver niobate-based antiferroelectric energy storage ceramic with high energy storage characteristics as claimed in claim 2, wherein in the step 2), the Ag weighed in the step 1) is specifically added2O powder and Nb2O5Powder and SrCO3Powder of Bi2O3Powder and HfO2Mixing the powder to form powder to be ball-milled, adding the powder to be ball-milled and grinding balls into a ball-milling tank, adding absolute ethyl alcohol into the ball-milling tank as a ball-milling medium, and starting a planetary ball mill for ball-milling treatment to obtain first base powder; adding the ball-milling powder, the milling balls and the absolute ethyl alcohol into a ball-milling tank according to the mass ratio of 1:1.5: 1; millThe ball adopts 0.3 g/zirconia ball, and the ball milling time is 24 h.
4. The low-temperature sintering method of silver niobate-based antiferroelectric energy storage ceramic with high energy storage characteristic as claimed in claim 2, wherein in the step 3), after the step 2) is completed, the first matrix powder in the ball milling tank is taken out, and then the first matrix powder is placed in a forced air drying oven for drying treatment to obtain the first matrix dry powder, wherein the drying temperature is controlled as follows: 90-110 ℃; putting the obtained mixed dry powder into a porcelain boat, compacting the mixed dry powder in the porcelain boat, then putting the porcelain boat into a tube furnace, and calcining the matrix dry powder in the porcelain boat at constant temperature under the conditions of oxygen atmosphere and 900 ℃, wherein the calcining time is controlled as follows: 6 h; and after the calcination is finished, taking the porcelain boat out of the tube furnace, naturally cooling the porcelain boat to room temperature, and forming first prefabricated substrate powder in the porcelain boat.
5. The method for low-temperature sintering of silver niobate-based antiferroelectric energy storage ceramic with high energy storage characteristics as claimed in claim 2, wherein in the step 4), Ba (OH) is weighed2·8H2O powder and H3BO3Mixing the powder and the CuO powder to form powder to be ball-milled, adding the powder to be ball-milled and grinding balls into a ball-milling tank together, adding deionized water into the ball-milling tank as a ball-milling medium, and starting a planetary ball mill for ball-milling treatment to obtain second base powder; adding the powder to be ball-milled, the grinding balls and the deionized water into a ball-milling tank according to the mass ratio of 1:1.5: 1; the grinding ball adopts 0.3 g/zirconia ball, and the ball milling time is 24 h.
6. The low-temperature sintering method of silver niobate-based antiferroelectric energy storage ceramic with high energy storage property as claimed in claim 2, wherein in the step 6), after the step 5) is completed, the second matrix powder in the ball milling tank is taken out, and then the second matrix powder is placed in a forced air drying oven for drying treatment to obtain a second matrix dry powder; the drying temperature is controlled as follows: about 100 ℃; putting the obtained second matrix dry powder into a crucible, compacting the second matrix dry powder in the crucible, covering the crucible with a cover, putting the crucible into a muffle furnace, and calcining the second matrix dry powder in the crucible at constant temperature under the conditions of atmospheric atmosphere and 810 ℃, wherein the calcining time is controlled as follows: 4 h; and after the calcination is finished, taking the crucible out of the muffle furnace, naturally cooling the crucible to room temperature, and forming prefabricated BCB powder in the crucible.
7. The low-temperature sintering method of silver niobate-based antiferroelectric energy storage ceramic with high energy storage property as claimed in claim 2, wherein in the step 7), the first prefabricated base powder obtained in the step 3) is poured into a ball milling tank to be ball milled for the second time with a milling ball and absolute ethyl alcohol, and then is dried to obtain prefabricated mixed powder A; putting the obtained prefabricated mixed powder A, the prefabricated BCB powder obtained in the step (6) and grinding balls into a ball milling tank for ball milling treatment, and adding absolute ethyl alcohol serving as a ball milling medium in the ball milling treatment process to obtain prefabricated mixed powder B; drying the obtained prefabricated mixed powder B to obtain prefabricated mixed dry powder;
the prefabricated mixed powder A, the first prefabricated matrix powder, the grinding ball and the absolute ethyl alcohol are added into a ball milling tank according to the mass ratio of 1:1.5: 1; the grinding balls adopt 0.3 g/zirconia balls, and the ball milling time is 24 hours; the drying process adopts a blast drying oven for drying, and the drying temperature is controlled as follows: 90-110 ℃;
in the prefabricated mixed powder B, the prefabricated mixed powder A, the prefabricated BCB powder, the grinding ball and the absolute ethyl alcohol are added into a ball milling tank according to the mass ratio of 1:1.5:1, and the molar weight of the prefabricated BCB powder is 1% of that of the prefabricated mixed powder A; the grinding balls adopt 0.3 g/zirconia balls, and the ball milling time is 24 hours; the drying process adopts a blast drying oven for drying, and the drying temperature is controlled as follows: 90-110 ℃.
8. The low-temperature sintering method of silver niobate-based antiferroelectric energy storage ceramic with high energy storage characteristic as claimed in claim 2, wherein in the step 8), PVA solution is prepared by weighing PVA and dissolving the PVA in deionized water, wherein the PVA solution has a mass percentage concentration of 5%; 0.1 ml-0.2 ml of PVA solution is added into each gram of prefabricated mixed dry powder; uniaxial pressing the powder particles obtained after sieving under the pressure of 150Mpa to form a blank; the specification of the sieve is as follows: the average pore diameter is 60 meshes to 100 meshes; the blank body is a cylindrical blank body with the cross section diameter of 10mm and the height of 0.8 mm-1.0 mm.
9. The low-temperature sintering method of silver niobate-based antiferroelectric energy storage ceramic with high energy storage characteristic as claimed in claim 2, wherein in the step 9), the blank obtained in the step 8) is subjected to glue removal at 600 ℃, and then is cooled to room temperature; the rubber discharging process comprises the following specific steps: under the atmosphere, heating a muffle furnace to 600 ℃ at the speed of 5 ℃/min, calcining the blank body at constant temperature for 2h, then cooling to 50 ℃ at the speed of 5 ℃/min, and then cooling to room temperature; placing the blank after natural cooling treatment in a rubber sleeve, vacuumizing, and then placing in a cold isostatic press for cold isostatic pressing treatment under the pressure of 300 Mpa; and (3) placing the blank subjected to cold isostatic pressing into a tubular furnace, heating the tubular furnace to 1000-1030 ℃ at the speed of 5 ℃/min in the oxygen atmosphere, and calcining the blank at constant temperature for 2h to obtain the silver niobate-based antiferroelectric energy storage ceramic with BCB as a sintering aid.
10. The low-temperature sintering method of the silver niobate-based antiferroelectric energy storage ceramic with high energy storage characteristics as claimed in claim 2, characterized by comprising the following steps:
1) the mass of each raw material is calculated according to the molar ratio when x is 0.02, and Ag is weighed respectively2O powder and Nb2O5Powder and SrCO3Powder of Bi2O3Powder and HfO2Powder; wherein, Ag2The purity of the O powder is more than or equal to 99.70 percent; nb2O5The purity of the powder is more than or equal to 99.99 percent; SrCO3The purity of the powder is more than or equal to 99.00 percent; bi2O3Powder, HfO2The purity of the powder is 99.9%;
2) weighing Ag2O powder and Nb2O5Powder and SrCO3Powder of Bi2O3Powder and HfO2Uniformly mixing the powder to form powder to be ball-milled, adding the powder into a ball-milling tank, adding absolute ethyl alcohol into the ball-milling tank to serve as a ball-milling medium, and opening the ball-milling tank to perform ball-milling treatment to obtain first matrix powder; in the ball milling process, powder to be ball milled, grinding balls and absolute ethyl alcohol are added into a ball milling tank according to the mass ratio of 1:1.5:1, wherein the grinding balls are zirconia balls with the mass ratio of 0.3 g/ball, and the ball milling time is 24 hours;
3) taking out the first matrix powder in the ball milling tank in the step 2, and then placing the first matrix powder in a forced air drying oven for drying treatment at 100 ℃ to obtain first matrix dry powder; putting the first matrix dry powder into a porcelain boat and compacting, putting the porcelain boat into a tube furnace, and calcining the first matrix dry powder in a crucible at 900 ℃ in an oxygen atmosphere for 6 hours; after the calcination is finished, taking the porcelain boat out of the tube furnace, naturally cooling the porcelain boat to room temperature, and forming first prefabricated substrate powder in the porcelain boat;
4) calculating and weighing Ba (OH) according to the molar ratio of 1:2:12·8H2O powder, H3BO3Powder and CuO powder. Wherein, Ba (OH)2·8H2The purity of O powder is more than or equal to 98.00 percent, and H3BO3The purity of the powder is more than or equal to 99.80 percent, and the purity of the CuO powder is more than or equal to 99.00 percent;
5) weighing Ba (OH)2·8H2O powder and H3BO3Mixing the powder and the CuO powder to form powder to be subjected to ball milling and adding the powder and zirconium balls into a ball milling tank, adding deionized water into the ball milling tank as a ball milling medium, and starting a planetary ball mill for ball milling treatment to obtain second base powder; in the ball milling process, powder to be ball milled, grinding balls and deionized water are added into a ball milling tank according to the mass ratio of 1:1.5:1, wherein the grinding balls are zirconia balls with the mass ratio of 0.3 g/ball, and the ball milling time is 24 hours;
6) taking out the second matrix powder in the ball milling tank in the step 5, and then placing the second matrix powder in a forced air drying oven at about 100 ℃ for drying treatment to obtain second matrix dry powder; putting the second matrix dry powder into a crucible, compacting and covering the crucible with a cover, then putting the crucible into a muffle furnace, and calcining the second matrix dry powder in the crucible at the constant temperature of 810 ℃ in an air atmosphere, wherein the calcining time is controlled to be 4 hours; after the calcination is finished, taking the crucible out of the muffle furnace, naturally cooling the crucible to room temperature, and forming prefabricated BCB powder in the crucible;
7) pouring the first prefabricated base powder obtained in the step 3) into a ball milling tank, carrying out secondary ball milling with a grinding ball and absolute ethyl alcohol, and then drying to obtain prefabricated mixed powder A, wherein the first prefabricated base powder, the grinding ball and the absolute ethyl alcohol are added into the ball milling tank according to the mass ratio of 1:1.5: 1; the grinding balls adopt 0.3 g/zirconia balls, and the ball milling time is 24 hours; the drying process adopts a blast drying oven for drying, and the drying temperature is controlled as follows: 90-110 ℃; then placing the prefabricated mixed powder A and the prefabricated BCB powder into a ball milling tank to be ball milled together with a milling ball, wherein the molar weight of the prefabricated BCB powder is 1% of that of the prefabricated mixed powder A, and adding absolute ethyl alcohol as a ball milling medium in the ball milling process to obtain prefabricated mixed powder B; in the prefabricated mixed powder B, the prefabricated mixed powder A, prefabricated BCB powder, grinding balls and absolute ethyl alcohol are added into a ball-milling tank according to the mass ratio of 1:1.5: 1; the grinding balls adopt 0.3 g/zirconia balls, and the ball milling time is 24 hours; the drying process adopts a blast drying oven for drying, and the drying temperature is controlled as follows: 90-110 ℃;
8) weighing PVA and dissolving the PVA in deionized water to prepare a PVA solution with the mass percentage concentration of 5%; adding the PVA solution into the prefabricated mixed dry powder for granulation treatment to obtain powder particles; wherein, 0.1ml of PVA solution is added into each gram of the prefabricated mixed dry powder; after the granulation treatment is finished, the formed powder particles pass through a sieve, and the powder particles with larger particle size and the powder particles with smaller particle size are removed; the specification of the sieve is as follows: the average aperture is 60-100 meshes, and the powder particles between 60-100 meshes are taken for tabletting; pressing the sieved powder particles under 150Mpa to obtain blank; the blank body is a cylindrical blank body with the cross section diameter of 10mm and the height of 0.8 mm-1.0 mm;
9) and (3) carrying out rubber discharge on the blank obtained in the step (8) at the temperature of 600 ℃, wherein the rubber discharge comprises the following specific processes: heating a muffle furnace to 600 ℃ at the speed of 5 ℃/min in the air atmosphere, calcining the blank body at constant temperature for 2h, then cooling to 50 ℃ at the speed of 5 ℃/min, and naturally cooling to room temperature to obtain the blank body after rubber removal; and putting the blank after the binder removal into a rubber sleeve, vacuumizing, then placing the rubber sleeve into a cold static press for further densification under the pressure of 150Mpa, putting the blank after isostatic pressing into a tubular furnace, heating the muffle furnace to 1030 ℃ at the speed of 5 ℃/min under the oxygen atmosphere, and calcining the blank for 2 hours at constant temperature to obtain the silver niobate-based antiferroelectric energy storage ceramic taking BCB as a sintering aid.
Technical Field
The invention relates to a ceramic material, in particular to a silver niobate-based antiferroelectric energy storage ceramic with high energy storage property and a low-temperature sintering method thereof.
Background
The solid dielectric ceramic has the characteristics of high power density, high charging and discharging speed and the like, and has great application requirements in the fields of smart grids, electric power automobiles, advanced weaponry and the like. Dielectric ceramics are classified into linear dielectrics and nonlinear dielectrics according to the relationship between the dielectric constant and the electric field intensity. Linear dielectrics are generally characterized by low dielectric constants, low dielectric losses, and high breakdown field strengths. The nonlinear dielectric is mainly divided into paraelectric materials, ferroelectric materials, antiferroelectric materials and relaxor ferroelectric materials, the dielectric constant of which has a certain functional relationship with the electric field intensity and is higher than that of the linear dielectric materials.
The energy storage density of a dielectric is mainly related to the dielectric constant and the breakdown field strength of the dielectric, and the high dielectric constant and the breakdown field strength are beneficial to the increase of energy storage. Dipoles which are mutually opposite and parallel exist in adjacent lattices in the antiferroelectric, the polarities are not displayed outwards, the dipoles are arranged in parallel again under the action of a high electric field, the conversion from a reversible antiferroelectric phase to a ferroelectric phase is realized, and a double-electric hysteresis loop favorable for dielectric energy storage is obtained. The antiferroelectric material is an excellent dielectric energy storage material due to the characteristics of low hysteresis, high saturation polarization, low residual polarization, high energy storage density and the like.
At present, the commercial antiferroelectric energy storage material in the market mainly comprises lead-based ceramic, and lead-containing substances produced in the preparation process of the lead-based ceramic cause great pollution to the environment, so that the development of the lead-free antiferroelectric energy storage ceramic with good performance has very important significance. At present, research focuses on lead-free energy storage materials, and focuses on barium titanate-based, sodium niobate-based and silver niobate-based materials, wherein the silver niobate-based materials have great advantages in a plurality of lead-free energy storage materials due to high polarization strength and double hysteresis lines, but the problems of low breakdown field strength, complex preparation process, unstable anti-ferroelectric phase and the like exist, so that the improvement of energy storage density is limited.
Silver niobate is a typical perovskite (ABO)3) A structural material. At present, research on silver niobate-based antiferroelectric energy storage ceramics mainly starts from two aspects of stabilizing the antiferroelectric phase and improving the breakdown field strength of the antiferroelectric phase. The specific implementation scheme reduces the tolerance factor t through ion doping, stabilizes the antiferroelectric phase and improves the phase change field strength; or thereby reducing the grain size of the sample to increase its breakdown field strength. According to the difference of ion doping substitution positions, the modification of the silver niobate-based ceramic mainly comprises the following steps: a-position substitution, B-position substitution and A/B-position joint substitution. For the study of the substitution at the A position, representative Ag is compared0.94La0.02NbO3The energy storage of the system reaches 4.4J/cm3The efficiency reaches 73%; for substitution at the B position, AgNb0.85Ta0.15O3The system energy storage reaches 4.2J/cm3The efficiency reaches 69%; for co-substitution of A/B position, Ag0.97Nd0.01Ta0.20Nb0.80O3The energy storage of the system reaches 6.5J/cm3The efficiency reaches 71 percent. However, the preparation process of the silver niobate-based antiferroelectric energy storage ceramic is generally required to be kept at the high temperature of 1100-1200 ℃ for 4-6h in an oxygen atmosphere, and is much more complicated than that of other lead-free energy storage ceramics.
Therefore, how to simplify the preparation process of the silver niobate-based antiferroelectric energy storage ceramic on the premise of ensuring high energy storage characteristics becomes a difficult problem in the technical field.
Disclosure of Invention
In view of the above situation, in order to overcome the defects of the prior art, the present invention aims to provide a silver niobate-based antiferroelectric energy storage ceramic with high energy storage characteristics and a low-temperature sintering method thereof, which can effectively solve the problems of low breakdown field strength, complex preparation process and unstable antiferroelectric phase in the prior art.
The technical scheme for solving the problem is that the invention uses the component (1-x) AgNbO3-x (Sr)0.7Bi0.2)HfO3Based on-0.01 BCB (1-x) AN-xSBH-y BCB for short), high-purity Ag is prepared by adopting a traditional solid-phase reaction method2O powder and Nb2O5Powder and SrCO3Powder of Bi2O3Powder and HfO2The powder is used as a base material; with Ba (OH)2·8H2O powder and H3BO3BaCu (B) prepared by powder and CuO powder according to the mol ratio of 1:2:12O7) As a sintering aid, the silver niobate-based antiferroelectric energy storage ceramic with high energy storage density, high energy storage efficiency and good temperature stability is prepared by a simple and easily-realized process.
The method specifically comprises the following steps:
1) the mass of each raw material is calculated according to the molar ratio of 0 to 0.02 to 0.04 to 0.05 to 0.055 to 0.06, and Ag is weighed respectively2O powder and Nb2O5Powder and SrCO3Powder of Bi2O3Powder and HfO2Powder of Ag in2The purity of O powder (Shanghai test of Chinese medicine) is more than or equal to 99.7 percent, and Nb2O5The purity of the powder (Shanghai test of Chinese medicine) is more than or equal to 99.99 percent, and SrCO3The purity of the powder (Shanghai test of Chinese medicine) is more than or equal to 99.00 percent, and the Bi content is Bi2O3Powder (Shanghai test of Chinese medicine), HfO2The purity of the powder (Meclin) is 99.9%;
2) firstly, the Ag weighed in the step 1) is weighed2O powder and Nb2O5Powder and SrCO3Powder of Bi2O3Powder and HfO2Mixing and ball-milling the powder to form first matrix powder;
3) sequentially drying, calcining (pre-burning) and cooling the matrix powder obtained in the step 2) to obtain first prefabricated matrix powder;
4) calculating and weighing Ba (OH) according to the molar ratio of 1:2:12·8H2O powder and H3BO3Powder and CuO powder, wherein Ba (OH)2·8H2The purity of O powder (Shanghai test of Chinese medicine) is more than or equal to 98.00 percent; h3BO3The purity of the powder (Shanghai test of Chinese medicine) is more than or equal to 99.80 percent; the purity of CuO powder (Shanghai test of Chinese medicine) is more than or equal to 99.00 percent;
5) firstly, weighing Ba (OH) in the step 4)2·8H2O powder and H3BO3Mixing and ball-milling the powder and the CuO powder to form second matrix powderFeeding;
6) drying, calcining and cooling the second matrix powder obtained in the step 5) in sequence to obtain prefabricated BCB powder;
7) performing secondary ball milling and drying on the first prefabricated base powder obtained in the step 3), mixing the first prefabricated base powder with the prefabricated BCB powder obtained in the step 6), continuously performing ball milling, and performing ball milling and drying treatment in sequence to obtain prefabricated mixed dry powder;
8) preparing PVA solution, and adding the prepared PVA solution into the prepared mixed dry powder obtained in the step 7) for granulation to form powder particles; sieving the prepared powder particles, and removing large powder particles and small powder particles; finally pressing the powder particles obtained after sieving into a blank;
9) and (3) sequentially carrying out glue discharging, cooling, natural cooling, cold isostatic pressing and calcining on the blank obtained in the step 8) to obtain the silver niobate-based antiferroelectric energy storage ceramic taking BCB as the sintering aid.
In the step 2), Ag weighed in the step 1) is specifically added2O powder and Nb2O5Powder and SrCO3Powder of Bi2O3Powder and HfO2Mixing the powder to form powder to be ball-milled, adding the powder to be ball-milled and grinding balls into a ball-milling tank, adding absolute ethyl alcohol into the ball-milling tank as a ball-milling medium, and starting a planetary ball mill for ball-milling treatment to obtain first base powder; adding the ball-milling powder, the milling balls and the absolute ethyl alcohol into a ball-milling tank according to the mass ratio of 1:1.5: 1; the grinding ball adopts 0.3 g/zirconia ball, and the ball milling time is 24 h.
In the step 3), after the step 2) is completed, taking out the first matrix powder in the ball milling tank, and then placing the first matrix powder in a blast drying oven for drying treatment to obtain first matrix dry powder, wherein the drying temperature is controlled as follows: 90-110 ℃; putting the obtained mixed dry powder into a porcelain boat, compacting the mixed dry powder in the porcelain boat, putting the porcelain boat into a tube furnace, and calcining the matrix dry powder in the porcelain boat at constant temperature under the conditions of oxygen atmosphere and 900 ℃, wherein the calcining time is controlled to be 6 hours; after the calcination is finished, taking the porcelain boat out of the tube furnace, naturally cooling the porcelain boat to room temperature (23 +/-2 ℃), and forming first prefabricated base powder in the porcelain boat.
In the step 4), weighing Ba (OH)2·8H2O powder and H3BO3Mixing the powder and the CuO powder to form powder to be ball-milled, adding the powder to be ball-milled and grinding balls into a ball-milling tank together, adding deionized water into the ball-milling tank as a ball-milling medium, and starting a planetary ball mill for ball-milling treatment to obtain second base powder; adding the powder to be ball-milled, the grinding balls and the deionized water into a ball-milling tank according to the mass ratio of 1:1.5: 1; the grinding ball adopts 0.3 g/zirconia ball, and the ball milling time is 24 h.
In the step 6), after the step 5) is finished, taking out the second matrix powder in the ball milling tank, and then placing the second matrix powder in a blast drying oven for drying treatment to obtain second matrix dry powder; the drying temperature is controlled as follows: about 100 ℃; putting the obtained second matrix dry powder into a crucible, compacting the second matrix dry powder in the crucible, covering the crucible with a cover, putting the crucible into a muffle furnace, and calcining the second matrix dry powder in the crucible at constant temperature under the conditions of atmospheric atmosphere and 810 ℃, wherein the calcining time is controlled to be 4 hours; and after the calcination is finished, taking the crucible out of the muffle furnace, naturally cooling the crucible to room temperature, and forming prefabricated BCB powder in the crucible.
In the step 7), the first prefabricated base powder obtained in the step 3) is poured into a ball milling tank to be milled for the second time with a milling ball and absolute ethyl alcohol, and then the second prefabricated base powder is dried to obtain prefabricated mixed powder A; putting the obtained prefabricated mixed powder A, the prefabricated BCB powder obtained in the step (6) and grinding balls into a ball milling tank for ball milling treatment, and adding absolute ethyl alcohol serving as a ball milling medium in the ball milling treatment process to obtain prefabricated mixed powder B; drying the obtained prefabricated mixed powder B to obtain prefabricated mixed dry powder;
in the prefabricated mixed powder A, adding a first prefabricated matrix powder, grinding balls and absolute ethyl alcohol into a ball-milling tank according to the mass ratio of 1:1.5: 1; the grinding balls adopt 0.3 g/zirconia balls, and the ball milling time is 24 hours; the drying process adopts a blast drying oven for drying, and the drying temperature is controlled as follows: 90-110 ℃;
in the prefabricated mixed powder B, the prefabricated mixed powder A, the prefabricated BCB powder, the grinding ball and the absolute ethyl alcohol are added into a ball milling tank according to the mass ratio of 1:1.5:1, and the molar weight of the prefabricated BCB powder is 1% of that of the prefabricated mixed powder A; the grinding balls adopt 0.3 g/zirconia balls, and the ball milling time is 24 hours; the drying process adopts a blast drying oven for drying, and the drying temperature is controlled as follows: 90-110 ℃.
In the step 8), the PVA solution is prepared by weighing PVA and dissolving the PVA in deionized water to prepare a PVA solution with the mass percentage concentration of 5%;
in the step 8), 0.1ml to 0.2ml of PVA solution is added into each gram of prefabricated mixed dry powder;
in the step 8), the powder particles obtained after sieving are uniaxially pressed under the pressure of 150Mpa to form a blank;
in the step 8), the specification of the sieve is as follows: the average pore diameter is 60 meshes to 100 meshes;
in the step 8), the blank is a cylindrical blank (0.3 g/piece) with the cross section diameter of 10mm and the height of 0.8 mm-1.0 mm.
In the step 9), the embryo body obtained in the step 8) is subjected to degumming at 600 ℃, and then is cooled to room temperature (23 ℃ +/-2 ℃);
in the step 9), the rubber discharging process is as follows: under the atmosphere, heating a muffle furnace to 600 ℃ at the speed of 5 ℃/min, calcining the blank body at constant temperature for 2h, then cooling to 50 ℃ at the speed of 5 ℃/min, and then cooling to room temperature;
in the step 9), the blank after natural cooling treatment is placed in a rubber sleeve for vacuumizing and then placed in a cold isostatic press for cold isostatic pressing treatment under the pressure of 300 Mpa;
and 9), placing the blank subjected to the cold isostatic pressing treatment into a tube furnace, heating the tube furnace to 1000-1030 ℃ at the speed of 5 ℃/min in an oxygen atmosphere, and calcining the blank for 2h at constant temperature to obtain the silver niobate-based antiferroelectric energy storage ceramic with BCB as a sintering aid.
Silver niobate-based antiferroelectric storage using BCB as sintering aidThe silver niobate-based antiferroelectric energy storage ceramic prepared by the ceramic preparation method has the stoichiometric formula of (1-x) AgNbO3-x (Sr)0.7Bi0.2)HfO3Y BCB is (1-x) AN-x SBH-y BCB) wherein x is 0.02 to 0.06; y is 0.01; y is the molar ratio of BCB to (1-x) AN-x SBH, the invention simplifies the preparation process of the silver niobate-based antiferroelectric energy storage ceramic on the premise of ensuring high energy storage property, prepares the silver niobate-based antiferroelectric energy storage ceramic with high energy storage density, high energy storage efficiency and good temperature stability, and is AN innovation in the preparation method of the silver niobate-based antiferroelectric energy storage ceramic.
Drawings
FIG. 1 is an SEM picture and an average grain size graph of a silver niobate-based antiferroelectric energy storage ceramic of the present invention.
FIG. 2 shows the actual density (rho) and theoretical density (rho) of the silver niobate-based antiferroelectric energy storage ceramicT) And relative density (p)R) And (4) a trend graph along with the doping content of the SBH.
FIG. 3(a) is a graph showing the breakdown field strength, (b) average grain size and (c) band gap of the silver niobate-based antiferroelectric energy storage ceramic of the present invention as a function of the doping content of SBH.
FIG. 4 is a graph showing the trend of (a) temperature-rising dielectric constant, (b) phase diagram, (c) dielectric loss and (d) imaginary part of electric modulus of the silver niobate-based antiferroelectric energy storage ceramic according to the present invention along with the doping content of SBH.
Fig. 5 is a graph of XPS spectra and trends of oxygen vacancy content versus SBH doping content for O1s for silver niobate-based antiferroelectric energy storage ceramics of the present invention where x is 0.00 and 0.06.
Fig. 6 is a graph showing the trend of change of (a) the hysteresis loop, (b) the energy storage density and efficiency of the silver niobate-based antiferroelectric energy storage ceramic with SBH doping content at room temperature, and the trend of change of (c) the energy storage density and (d) the efficiency of the silver niobate-based antiferroelectric energy storage ceramic with temperature, wherein x is 0.055.
Detailed Description
The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples.
Example 1
When the method is implemented, the method specifically comprises the following steps:
1) the mass of each raw material is calculated according to the molar ratio when x is 0.02, and Ag is weighed respectively2O powder and Nb2O5Powder and SrCO3Powder of Bi2O3Powder and HfO2Powder; wherein, Ag2The purity of O powder (Shanghai test of Chinese medicine) is more than or equal to 99.70 percent; nb2O5The purity of the powder (Shanghai test of Chinese medicine) is more than or equal to 99.99 percent; SrCO3The purity of the powder (Shanghai test of Chinese medicine) is more than or equal to 99.00 percent; bi2O3Powder (Shanghai test of Chinese medicine); HfO2The purity of the powder (Meclin) is 99.9%;
2) weighing Ag2O powder and Nb2O5Powder and SrCO3Powder of Bi2O3Powder and HfO2Uniformly mixing the powder to form powder to be ball-milled, adding the powder into a ball-milling tank, adding absolute ethyl alcohol into the ball-milling tank to serve as a ball-milling medium, and opening the ball-milling tank to perform ball-milling treatment to obtain first matrix powder; in the ball milling process, powder to be ball milled, grinding balls and absolute ethyl alcohol are added into a ball milling tank according to the mass ratio of 1:1.5:1, wherein the grinding balls are zirconia balls with the mass ratio of 0.3 g/ball, and the ball milling time is 24 hours;
3) taking out the first matrix powder in the ball milling tank in the step 2, and then placing the first matrix powder in a forced air drying oven for drying treatment at 100 ℃ to obtain first matrix dry powder; putting the first matrix dry powder into a porcelain boat and compacting, putting the porcelain boat into a tube furnace, and calcining the first matrix dry powder in a crucible at 900 ℃ in an oxygen atmosphere for 6 hours; after the calcination is finished, taking the porcelain boat out of the tube furnace, naturally cooling the porcelain boat to room temperature, and forming first prefabricated substrate powder in the porcelain boat;
4) calculating and weighing Ba (OH) according to the molar ratio of 1:2:12·8H2O powder, H3BO3Powder and CuO powder. Wherein, Ba (OH)2·8H2The purity of O powder (Shanghai test of Chinese medicine) is more than or equal to 98.00 percent, and H3BO3The purity of the powder (national pharmaceutical Shanghai test) is more than or equal to 99.80 percent, and the purity of the CuO powder (national pharmaceutical Shanghai test) is more than or equal to 99.00 percent;
5) weighing Ba (OH)2·8H2O powder and H3BO3Mixing the powder and the CuO powder to form powder to be subjected to ball milling and adding the powder and zirconium balls into a ball milling tank, adding deionized water into the ball milling tank as a ball milling medium, and starting a planetary ball mill for ball milling treatment to obtain second base powder; in the ball milling process, powder to be ball milled, grinding balls and deionized water are added into a ball milling tank according to the mass ratio of 1:1.5:1, wherein the grinding balls are zirconia balls with the mass ratio of 0.3 g/ball, and the ball milling time is 24 hours;
6) taking out the second matrix powder in the ball milling tank in the step 5, and then placing the second matrix powder in a forced air drying oven at about 100 ℃ for drying treatment to obtain second matrix dry powder; putting the second matrix dry powder into a crucible, compacting and covering the crucible with a cover, then putting the crucible into a muffle furnace, and calcining the second matrix dry powder in the crucible at the constant temperature of 810 ℃ in an air atmosphere, wherein the calcining time is controlled to be 4 hours; after the calcination is finished, taking the crucible out of the muffle furnace, naturally cooling the crucible to room temperature, and forming prefabricated BCB powder in the crucible;
7) pouring the first prefabricated base powder obtained in the step 3) into a ball milling tank, carrying out secondary ball milling with a grinding ball and absolute ethyl alcohol, and then drying to obtain prefabricated mixed powder A, wherein the first prefabricated base powder, the grinding ball and the absolute ethyl alcohol are added into the ball milling tank according to the mass ratio of 1:1.5: 1; the grinding balls adopt 0.3 g/zirconia balls, and the ball milling time is 24 hours; the drying process adopts a blast drying oven for drying, and the drying temperature is controlled as follows: 90-110 ℃; then putting the prefabricated mixed powder A and the prefabricated BCB powder into a ball milling tank to be ball milled together with a grinding ball (the molar weight of the prefabricated BCB powder is 1 percent of that of the prefabricated mixed powder A), and adding absolute ethyl alcohol as a ball milling medium in the ball milling process to obtain prefabricated mixed powder B; in the prefabricated mixed powder B, the prefabricated mixed powder A, prefabricated BCB powder, grinding balls and absolute ethyl alcohol are added into a ball-milling tank according to the mass ratio of 1:1.5: 1; the grinding balls adopt 0.3 g/zirconia balls, and the ball milling time is 24 hours; the drying process adopts a blast drying oven for drying, and the drying temperature is controlled as follows: 90-110 ℃;
8) weighing PVA and dissolving the PVA in deionized water to prepare a PVA solution with the mass percentage concentration of 5%; adding the PVA solution into the prefabricated mixed dry powder for granulation treatment to obtain powder particles; wherein, 0.1ml of PVA solution is added into each gram of the prefabricated mixed dry powder; after the granulation treatment is finished, the formed powder particles pass through a sieve, and the powder particles with larger particle size and the powder particles with smaller particle size are removed; the specification of the sieve is as follows: the average aperture is 60-100 meshes, and the powder particles between 60-100 meshes are taken for tabletting; pressing the sieved powder particles under 150Mpa to obtain blank; the blank is a cylindrical blank (0.3 g/piece) with the cross section diameter of 10mm and the height of 0.8 mm-1.0 mm;
9) and (3) carrying out rubber discharge on the blank obtained in the step (8) at the temperature of 600 ℃, wherein the rubber discharge comprises the following specific processes: heating a muffle furnace to 600 ℃ at the speed of 5 ℃/min in the air atmosphere, calcining the blank body at constant temperature for 2h, then cooling to 50 ℃ at the speed of 5 ℃/min, and naturally cooling to room temperature to obtain the blank body after rubber removal; and putting the blank after the binder removal into a rubber sleeve, vacuumizing, then placing the rubber sleeve into a cold static press for further densification under the pressure of 150Mpa, putting the blank after isostatic pressing into a tubular furnace, heating the muffle furnace to 1030 ℃ at the speed of 5 ℃/min under the oxygen atmosphere, and calcining the blank for 2 hours at constant temperature to obtain the silver niobate-based antiferroelectric energy storage ceramic taking BCB as a sintering aid.
As shown in figure 1, the (1-x) AN-xSBH-yBCB silver niobate-based antiferroelectric energy storage ceramic sample prepared by the low-temperature sintering process has uniform grain size. With increasing SBH doping content, the sample average grain size gradually decreased from 5.07 μm for x 0.00 component to 2.23 μm for x 0.06 component. Meanwhile, the relative density of the prepared samples is higher than 98% (fig. 2). The reduction in grain size is accompanied by an increase in breakdown field strength (as shown in fig. 3a and b), which in turn facilitates an increase in energy storage density. It can be found by ultraviolet-visible absorption spectroscopy (UV-vis) that as the doping content of SBH increases, the band gap of the system gradually increases from 2.71eV for x ═ 0.00 composition to 2.77eV for x ═ 0.06 composition (as shown in fig. 3 c).
With the increase of the doping content of SBH, the phase of (1-x) AN-xSBH-yBCB silver niobate-based antiferroelectric energy storage ceramicTemperature (M)1-M2、M2-M3And M2-M3) Gradually moving towards a lower temperature as shown in fig. 4a and b. Wherein, when the SBH doping content is higher than 0.04, M1-M2The phase transition temperature has been reduced to below-150 c, indicating a gradual increase in the stability of the antiferroelectric phase at room temperature. At the same time, M2-M3The phase transition peak is gradually dispersed, which shows that the SBH doping enhances the relaxation property of the material, thereby being beneficial to improving the energy storage efficiency. FIG. 4c shows the dielectric loss of (1-x) AN-xSBH-yBCB silver niobate-based antiferroelectric energy storage ceramic in the temperature range of-150 ℃ to 450 ℃ (the inset shows the dielectric loss of each component at room temperature). The dielectric loss at room temperature was reduced from 0.00989 with x being 0.00 component to 0.00016 with x being 0.06 component. FIG. 4d is a graph showing the variation trend of the imaginary part of the electric modulus of the (1-x) AN-xSBH-yBCB silver niobate-based antiferroelectric energy storage ceramic at 400 ℃ along with the doping content of SBH. All components exhibited unimodal behavior over the tested frequency range, indicating good electrical uniformity of the samples.
Fig. 5 is a graph of the O1s XPS spectra and the trend of oxygen vacancy content as a function of SBH doping content for x ═ 0.00 and 0.06 ceramics. The O1s peak can be fitted to two peaks, the peak at the lower and higher binding energies representing lattice oxygen (O) respectivelyL) And vacancy oxygen (O)V). Vacancy oxygen (O) with increasing SBH doping contentV) Gradually decreases as shown in fig. 5 c.
As the SBH doping level increases, the average grain size decreases, the dielectric loss decreases, the band gap increases and vacancy oxygen (O)V) The reduction of the content is beneficial to the increase of the breakdown field intensity. Meanwhile, as the stability of the antiferroelectric phase at room temperature is gradually enhanced, the (1-x) AN-xSBH-yBCB silver niobate-based antiferroelectric energy storage ceramic shows good energy storage characteristics and temperature stability, as shown in FIG. 6. As the SBH content increases, the phase transition field strength gradually shifts to a higher field while maintaining a higher maximum polarization, as shown in fig. 6 a. When x is 0.055, the energy storage density reaches 6.1J/cm3The energy storage efficiency reaches 73% (fig. 6 b). Fig. 6c and d are the hysteresis loop and energy storage characteristics of the x ═ 0.055 composition at different temperatures (25 ℃ to 120 ℃) in an electric field of 290 kV/cm. Energy storage density and storage of 0.055 componentThe energy efficiency changes with the temperature are respectively 3.8% and 1.5%, and the temperature stability is excellent.
The invention uses BaCu (B)2O7) The silver niobate-based antiferroelectric energy storage ceramic which is used as a sintering aid and has high energy storage density, high energy storage efficiency and good temperature stability is prepared by a simple and easily-realized process.