阅读说明：本技术 一种居里温度可调控的bczt储能陶瓷材料的制备方法 (Preparation method of BCZT energy storage ceramic material with adjustable Curie temperature ) 是由 王显威 张碧辉 李永艳 史永闯 王圣洁 唐颖 尚淑英 胡艳春 尹少骞 尚军 于 2019-10-14 设计创作，主要内容包括：本发明公开了一种居里温度可调控的BCZT储能陶瓷材料的制备方法,具体为：制备金属离子比例和Ba<Sub>0.85</Sub>Ca<Sub>0.15</Sub>Zr<Sub>0.1</Sub>Ti<Sub>0.9</Sub>O<Sub>3</Sub>为1.25:1的溶液,并调节pH值,加热制得溶胶；将溶胶置于鼓风干燥箱中干燥,研磨成粉料；将制得的粉料置于马弗炉中煅烧成BCZT氧化物粉体；将BCZT氧化物粉体研磨造粒成型后置于马弗炉中烧结；最后将烧结得到的陶瓷材料,两面涂覆银浆料,在一定温度下烧结固化形成金属银电极即可。本发明采用溶胶-凝胶法制得的Ba<Sub>0.85</Sub>Ca<Sub>0.15</Sub>Zr<Sub>0.1</Sub>Ti<Sub>0.9</Sub>O<Sub>3</Sub>陶瓷材料,有效地将BCZT铁电陶瓷材料的居里温度调控至室温附近,具有工艺简单、成本低廉、储能密度和储能效率高等优点。(The invention discloses a preparation method of a BCZT energy storage ceramic material with adjustable Curie temperature, which comprises the following steps: preparation of Metal ion ratio and Ba 0.85 Ca 0.15 Zr 0.1 Ti 0.9 O 3 1.25:1, adjusting the pH value, and heating to obtain sol; drying the sol in a blast drying oven, and grinding into powder; placing the prepared powder in a muffle furnace to calcine the powder into BCZT oxide powder; grinding, granulating and molding BCZT oxide powder, and sintering in a muffle furnace; and finally, coating silver slurry on two surfaces of the ceramic material obtained by sintering, and sintering and curing at a certain temperature to form the metal silver electrode. The invention adopts a sol-gel method to prepare Ba 0.85 Ca 0.15 Zr 0.1 Ti 0.9 O 3 The ceramic material effectively regulates and controls the Curie temperature of the BCZT ferroelectric ceramic material to be close to the room temperature, and has the advantages of simple process, low cost, high energy storage density, high energy storage efficiency and the like.)

1. A preparation method of a BCZT energy storage ceramic material with adjustable Curie temperature is characterized by comprising the following specific steps:

step S1: with Ba (NO)₃)₂、Ca(NO₃)₂·4H₂O、ZrOCl₂·8H₂O, tetrabutyl titanate, ammonia water and citric acid are used as initial raw materials, wherein the raw materials are Ba_0.85Ca_0.15Zr_0.1Ti_0.9O₃Respectively weighing raw material Ba (NO)₃)₂、Ca(NO₃)₂·4H₂O、ZrOCl₂·8H₂O and tetrabutyl titanate;

step S2: respectively dissolving tetrabutyl titanate and citric acid in 10mL and 30mL of ethanol, respectively stirring until the tetrabutyl titanate and the citric acid are completely dissolved, and then dripping the ethanol solution of tetrabutyl titanate into the ethanol solution of citric acid to obtain a mixed solution A;

step S3: zr (NO)₃)₄·5H₂O、Ca(NO₃)₂·4H₂O and Ba (NO)₃)₂Dissolving in 30mL of deionized water, heating and stirring until the mixture is completely dissolved to obtain a mixed solution B;

step S4: dropwise adding the mixed solution B obtained in the step S3 into the mixed solution A obtained in the step S2 to obtain a mixed solution C, dropwise adding ammonia water to adjust the pH value of the mixed solution C to 5-9, and continuously stirring at 80 ℃ to obtain a clear transparent solution;

step S5: stirring the clear transparent solution obtained in the step S4 in a water bath at 80 ℃ for 4 hours, and then increasing the viscosity of the solution to finally form yellow transparent sol;

step S6: drying the yellow transparent gel obtained in the step S5 in a forced air drying oven at 150 ℃ for 24h, and then uniformly grinding to obtain black powder;

step S7: putting the black powder obtained in the step S6 into a muffle furnace, heating to 1000 ℃ at the heating rate of 5 ℃/min, and calcining for 4h to obtain Ba_0.85Ca_0.15Zr_0.1Ti_0.9O₃Oxide powder;

step S8: ba obtained in step S7_0.85Ca_0.15Zr_0.1Ti_0.9O₃Adding 3wt% of PVA into oxide powder, grinding and granulating, molding under 200MPa, heating to 1300 ℃ at a heating rate of 5 ℃/min in a muffle furnace, and sintering for 2h to obtain Ba_0.85Ca_0.15Zr_0.1Ti_0.9O₃An oxide ceramic material;

step S9: ba obtained in step S8_0.85Ca_0.15Zr_0.1Ti_0.9O₃Coating silver slurry on the oxide ceramic material, sintering at 600 ℃ for 20min, and curing to form a metal silver electrode, wherein the Ba is Ba_0.85Ca_0.15Zr_0.1Ti_0.9O₃The oxide ceramic material has high dielectric constant, energy storage density and energy storage efficiency, and can be used as an energy storage capacitor material.

2. The method for preparing a BCZT energy storage ceramic material with adjustable Curie temperature according to claim 1, wherein: and in the step S2, stirring the tetrabutyl titanate for 15min at the rotating speed of 300 revolutions per minute when the tetrabutyl titanate is dropwise added into the ethanol, wherein the molar ratio of the citric acid to the metal cations in the mixed solution A is 1.25: 1.

3. The method for preparing a BCZT energy storage ceramic material with adjustable Curie temperature according to claim 2, wherein: in step S4, when the pH value of the mixed solution C is adjusted to 9 by ammonia water, Ba is prepared_0.85Ca_0.15Zr_0.1Ti_0.9O₃The Curie temperature of the oxide ceramic material is regulated to 4 ℃, and the energy storage density is 1.07J/cm under a test electric field of 185kV/cm³The energy storage efficiency is 91.2%, and the high energy storage density and energy storage efficiency are obtained at room temperature due to the fact that the Curie temperature is regulated to be close to the room temperature, and the energy storage capacitor material can be used as an energy storage capacitor material at room temperature.

Technical Field

The invention belongs to the technical field of electronic materials and devices, and particularly relates to a preparation method of a BCZT energy storage ceramic material with adjustable Curie temperature.

Background

With the rapid development of energy storage technology, dielectric capacitors have received much attention due to their ultra-high power density. The energy storage dielectric capacitor can be applied to occasions needing larger power output, such as tanks, electromagnetic guns, directional energy weapons, electrified launching platforms and the like, all of the facilities need working current of more than 100kA, and common energy devices are difficult to meet the requirement. The dielectric capacitor has the limitations that the energy storage density and the energy storage efficiency are low, which is not beneficial to the miniaturization and the light weight of the energy storage element, and the stability of the nonlinear dielectric material near the phase transition temperature is poor, which restricts the application range of the dielectric capacitor. The key problem in achieving the application of energy storage dielectric capacitors is to achieve higher energy storage density and better stability, and the solution of the problem will bring a major breakthrough to the technical field of related energy sources.

The ferroelectric material is used as a nonlinear dielectric, and the storage density can be calculated by a formula (the electric displacement D of the ferroelectric with higher dielectric constant can be regarded as equal to the electric polarization strength P)Therefore, the energy storage density of the energy storage element is related to the breakdown field strength and the saturation polarization value, and the energy storage efficiency is related to the energy dissipation in the charging and discharging process. Therefore, how to reduce the residual polarization value of the material through different ways while keeping the higher saturation polarization value of the material and improve the breakdown field strength of the ceramic becomes a hotspot of the research on the energy storage dielectric ceramic. In recent years, researchers have focused on perovskite-type Ba_0.85Ca_0.15Zr_0.1Ti_0.9O₃(BCZT) ferroelectric ceramic material was systematically studied. Researches show that the Curie temperature of the BCZT ceramic material is about 120 ℃, excellent piezoelectric property, higher dielectric constant and very low dielectric loss are obtained at room temperature, and the BCZT ceramic material is obtained at room temperatureP-EThe ferroelectric hysteresis loop has a larger remanent polarization value (~ 12 mu C/cm)²). If the high energy storage density and the high energy storage efficiency near the room temperature are required to be realized, the Curie temperature of the BCZT can be regulated and controlled.

Disclosure of Invention

The invention solves the technical problem of providing an economical and practical preparation method of the BCZT energy storage ceramic material with adjustable Curie temperature, which has simple process and does not need complex post-treatment steps.

The invention adopts the following technical scheme for solving the technical problems, and the preparation method of the BCZT energy storage ceramic material with adjustable Curie temperature is characterized by comprising the following specific steps:

step S1: with Ba (NO)₃)₂、Ca(NO₃)₂·4H₂O、ZrOCl₂·8H₂O, tetrabutyl titanate, ammonia water and citric acid are used as initial raw materials, wherein the raw materials are Ba_0.85Ca_0.15Zr_0.1Ti_0.9O₃Respectively weighing raw material Ba (NO)₃)₂、Ca(NO₃)₂·4H₂O、ZrOCl₂·8H₂O and tetrabutyl titanate;

step S2: respectively dissolving tetrabutyl titanate and citric acid in 10mL and 30mL of ethanol, respectively stirring until the tetrabutyl titanate and the citric acid are completely dissolved, and then dripping the ethanol solution of tetrabutyl titanate into the ethanol solution of citric acid to obtain a mixed solution A;

step S3: zr (NO)₃)₄·5H₂O、Ca(NO₃)₂·4H₂O and Ba (NO)₃)₂Dissolving in 30mL of deionized water, heating and stirring until the mixture is completely dissolved to obtain a mixed solution B;

step S4: dropwise adding the mixed solution B obtained in the step S3 into the mixed solution A obtained in the step S2 to obtain a mixed solution C, dropwise adding ammonia water to adjust the pH value of the mixed solution C to 5-9, and continuously stirring at 80 ℃ to obtain a clear transparent solution;

step S5: stirring the clear transparent solution obtained in the step S4 in a water bath at 80 ℃ for 4 hours, and then increasing the viscosity of the solution to finally form yellow transparent sol;

step S6: drying the yellow transparent gel obtained in the step S5 in a forced air drying oven at 150 ℃ for 24h, and then uniformly grinding to obtain black powder;

step S7: putting the black powder obtained in the step S6 into a muffle furnace, heating to 1000 ℃ at the heating rate of 5 ℃/min, and calcining for 4h to obtain Ba_0.85Ca_0.15Zr_0.1Ti_0.9O₃Oxide powder;

step S8: ba obtained in step S7_0.85Ca_0.15Zr_0.1Ti_0.9O₃Adding 3wt% of PVA into oxide powder, grinding and granulating, molding under 200MPa, heating to 1300 ℃ at a heating rate of 5 ℃/min in a muffle furnace, and sintering for 2h to obtain Ba_0.85Ca_0.15Zr_0.1Ti_0.9O₃An oxide ceramic material;

step S9: ba obtained in step S8_0.85Ca_0.15Zr_0.1Ti_0.9O₃Coating silver slurry on the oxide ceramic material, sintering at 600 ℃ for 20min, and curing to form a metal silver electrode, wherein the Ba is Ba_0.85Ca_0.15Zr_0.1Ti_0.9O₃The oxide ceramic material has high dielectric constant, energy storage density and energy storage efficiency, and can be used as an energy storage capacitor material.

More preferably, the tetrabutyl titanate is stirred for 15min at a rotation speed of 300 rpm while being dropwise added to the ethanol in step S2, and the molar ratio of the citric acid to the metal cation in the mixed solution a is 1.25: 1.

More preferably, Ba is produced by adjusting the pH of the mixed solution C to 9 with aqueous ammonia in step S4_0.85Ca_0.15Zr_0.1Ti_0.9O₃The Curie temperature of the oxide ceramic material is regulated to 4 ℃, and the energy storage density is 1.07J/cm under a test electric field of 185kV/cm³The energy storage efficiency is 91.2%, and the high energy storage density and energy storage efficiency are obtained at room temperature due to the fact that the Curie temperature is regulated to be close to the room temperature, and the energy storage capacitor material can be used as an energy storage capacitor material at room temperature.

Compared with the prior art, the invention ensures that Ba is enabled by adjusting the pH value of the solution_0.85Ca_0.15Zr_0.1Ti_0.9O₃The Curie temperature of the ferroelectric ceramic material is reduced, and when the pH value of the solution is adjusted to 9 by ammonia water, the finally prepared Ba_0.85Ca_0.15Zr_0.1Ti_0.9O₃The dielectric constant of the ferroelectric ceramic material reaches the optimal value, the dielectric constant is 2500 at 100Hz room temperature, and the energy storage density reaches the optimal value of 1.1J/cm³And the energy storage density reaches an optimal value of 91%. The invention also has the following advantages and beneficial effects:

1. the invention can effectively reduce Ba by optimizing the pH value of the solution_0.85Ca_0.15Zr_0.1Ti_0.9O₃Curie temperature of the ceramic material, thereby refiningP-EThe electric hysteresis loop and the breakdown-resistant field strength are kept at a higher level, so that the energy storage density and the energy storage efficiency of the BCZT ceramic material are improved.

2. The preparation method is simple, does not need complex post-treatment steps, is economical and practical, and adopts the sol-gel method to prepare the Ba_0.85Ca_0.15Zr_0.1Ti_0.9O₃The ceramic material effectively reduces the Curie temperature of the BCZT ferroelectric ceramic material, and has the advantages of simple process, low cost, high energy storage density, high energy storage efficiency and the like.

Drawings

FIG. 1 is an XRD pattern of BCZT ceramic materials prepared in example 1 and example 2;

FIG. 2 shows the dielectric properties of BCZT ceramic materials prepared in examples 1 and 2;

fig. 3 is a leakage current of the BCZT ceramic materials prepared in examples 1 and 2;

FIG. 4 is a dielectric thermogram of BCZT ceramic material prepared in example 1 and example 2;

FIG. 5 is the room temperature of the BCZT ceramic materials prepared in examples 1 and 2P-EAn electric hysteresis loop;

fig. 6 is a graph of energy storage density and energy storage efficiency of the BCZT ceramic materials prepared in examples 1 and 2.

Detailed Description

The present invention is described in further detail below with reference to examples, but it should not be construed that the scope of the above subject matter of the present invention is limited to the following examples, and that all the technologies realized based on the above subject matter of the present invention belong to the scope of the present invention.