PZT-based energy storage ceramic material with core-shell structure as well as preparation method and application of PZT-based energy storage ceramic material

Abstract

The invention provides a PZT-based energy storage ceramic material with a core-shell structure as well as a preparation method and application of the PZT-based energy storage ceramic material. The PZT-based energy storage ceramic material has excellent characteristics of high polarization intensity and high breakdown electric field; the preparation method comprises the following steps: coating PBLZST tetragonal phase powder prepared by adopting a solid phase method with PLZST orthorhombic phase sol prepared by adopting a sol-gel method, and sintering at high temperature, so that ceramic grains form a core-shell microstructure with a strong polarization core and a high breakdown shell. The polarization intensity of the prepared PZT-based energy storage ceramic material can reach 35-55 [mu] C / cm < 2 >, and the breakdown electric field is about 350-400 kV / cm. The core-shell microstructure promotes the synchronous improvement of the polarization intensity and the breakdown electric field of the material. Therefore, the energy storage performance of the PZT-based energy storage ceramic material is remarkably improved at room temperature, and the recoverable energy storage density can reach about 8.96 J / cm < 3 >.

Description

Technical Field

[0001] This invention relates to the field of electronic materials technology, and in particular to a core-shell structured PZT-based energy storage ceramic material, its preparation method, and its application. Background Technology

[0002] In the field of lead-based dielectric ceramics, high discharge energy density (Wrec), high energy storage efficiency (η) and good temperature stability are the core performance requirements of materials to meet the application requirements of lightweight and integrated dielectric capacitors in pulse power devices. Multiphase composite is one of the important means to effectively improve the comprehensive energy storage performance of lead-based dielectric ceramics.

[0003] In lead-based antiferroelectric composite ceramic systems, combining two different antiferroelectric phases can fully leverage the synergistic effect of each phase component, enabling the composite material to possess comprehensive energy storage performance that a single-phase material cannot achieve. Furthermore, these antiferroelectric phases have similar compositions and crystal structures, exhibiting both good chemical compatibility and physical property matching. The composite of the two phases will not cause structural defects such as ceramic cracking due to interfacial stress mismatch, demonstrating excellent compatibility.

[0004] However, the preparation and modification of this type of composite ceramic in the existing technology still have significant technical defects: On the one hand, the electrical properties of the two antiferroelectric phases are inherently different. After the two phases are combined, element interdiffusion is likely to occur at the interface, which leads to changes in the grain boundary structure. The difference in electrical properties between grains and grain boundaries is further increased, and a large amount of charge will accumulate in the interface region, which will increase the dielectric constant of the material and reduce the breakdown field strength. At the same time, the relaxation discharge period of the polarized charge at the interface is relatively long, which means that the electrical energy cannot be completely released after the electric field is removed, resulting in increased energy loss of the material. On the other hand, the existing two-phase composites mostly adopt the traditional solid-state composite method. This method has the problems of low powder activity and high sintering temperature, which easily leads to microstructural defects such as coarse grains and high porosity in the composite ceramics. Coarse grains will lead to uneven electric field distribution inside the ceramics, causing electric field concentration at the grain boundaries. Pores become weak points in the breakdown of the material. The combined effect of the two will significantly reduce the breakdown field strength and energy storage efficiency of the composite ceramics. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to address the above-mentioned deficiencies in the prior art by providing a core-shell structured PZT-based energy storage ceramic material, its preparation method and application, so as to solve the technical problems of poor energy storage performance, low breakdown field strength and many microstructural defects in existing lead-based composite ceramics; wherein, the above-mentioned PZT-based energy storage ceramic material has the characteristics of high breakdown electric field and high energy storage density, and the preparation process is simple and low cost.

[0006] In a first aspect, the present invention provides a core-shell structured PZT-based energy storage ceramic material, comprising a core and a shell layer coated on the surface of the core in the form of a sol, wherein the core is a PBLZST material and the shell layer is a PLZST material; the general chemical formula of the PZT-based energy storage ceramic material is (1-x)PBLZST-xPLZST, where 0 < x < 1.

[0007] Specifically, the core-shell structured PZT-based energy storage ceramic material provided by this invention uses PBLZST tetragonal phase powder prepared by solid-state method as the core and PLZST orthorhombic phase sol prepared by sol-gel method to form the shell, with the general chemical formula (1-x)PBLZST-xPLZST (0 < x < 1). This material relies on a core-shell microstructure control strategy, combining the advantages of solid-state and sol-gel methods, to avoid the problems of low powder activity and numerous sintering defects in traditional solid-state composite methods, while also suppressing the two-phase... The element diffusion and grain boundary structural changes at the composite interface, through the synergistic effect of high polarization intensity achieved by the strong polarization nucleus and high breakdown field strength guaranteed by the high breakdown shell, significantly improve the discharge energy storage density and energy storage efficiency of the material, effectively reduce energy loss, refine the ceramic grains, reduce porosity, optimize the electric field distribution inside the ceramic, and reduce the risk of grain boundary electric field concentration and porosity breakdown. Ultimately, this PZT-based energy storage ceramic material has excellent breakdown performance, energy storage characteristics and temperature stability, with comprehensive performance that is significantly better than existing lead-based composite ceramic materials.

[0008] Preferably, the chemical formula of the PBLZST material is (Pb 0.90 Ba 0.04 La 0.04 (Zr) 0.65 Sn 0.3 Ti 0.05 The chemical formula of PLZST material is (PbO3); 0.97 La 0.02 (Zr) 0.93 Sn 0.05 Ti 0.02 )O3.

[0009] Specifically, the PZT-based energy storage ceramic material with the above-mentioned specific ratio can form an excellent synergistic effect by relying on the strong polarization characteristics of the tetragonal PBLZST core and the high breakdown characteristics of the orthorhombic PLZST shell. This effectively improves the polarization intensity and breakdown electric field intensity of the material, significantly increases the discharge energy storage density and energy storage efficiency, while reducing energy loss, refining ceramic grains, reducing porosity defects, optimizing the uniformity of the electric field distribution inside the ceramic, and also endowing the material with good temperature stability. The overall energy storage performance is greatly improved.

[0010] Preferably, the polarization intensity of the PZT-based energy storage ceramic material is 35–55 μC / cm. 2The breakdown electric field is 350–400 kV / cm, and the recoverable energy storage density at room temperature is 8.96 J / cm². 3 .

[0011] Specifically, the above-mentioned performance parameters of PZT-based energy storage ceramic materials demonstrate that the material possesses excellent electrical characteristics, including both high polarization intensity and high breakdown electric field. It can achieve ultra-high recoverable energy storage density, excellent energy storage performance, and stable overall electrical performance, which can fully meet the application requirements of pulse power devices for lightweight and integrated dielectric capacitors.

[0012] Secondly, the present invention also provides a method for preparing a PZT-based energy storage ceramic material with the above-described core-shell structure, comprising the following steps: S10 is made from PbO, BaCO3, La2O3, ZrO2, SnO2 and TiO2 as raw materials, and is formulated according to the standard stoichiometric ratio of PBLZST. The raw materials are ball-milled using the traditional solid-state method to refine the powder. After pre-calcination, the powder is ball-milled again to obtain PBLZST core layer powder. S20, in the form of C4H8O4Pb·3H2O, C6H9LaO6·1.5H2O, C8H 18 SnO, C 12 H 28 O4Zr, C 12 H 28 Using O4Ti, C3H6O3, C2H6O2 and C3H8O as raw materials, the raw materials were added in an orderly manner according to the stoichiometric ratio of PLZST and subjected to sol-gel treatment to obtain PLZST shell sol. S30 involves mixing PBLZST core powder with PLZST shell sol, followed by debinding, granulation, pressing, and sintering to obtain a PZT-based energy storage ceramic material with a core-shell structure.

[0013] Specifically, the above-mentioned preparation method has a simple and feasible process route with strong operational controllability. The solid-state method ensures the crystallinity and polarization characteristics of the core layer powder, and the sol-gel method achieves uniform coating of the core layer powder by the shell sol. This effectively avoids the defects of low powder activity, coarse grains, and high porosity in traditional solid-state composite methods, and also inhibits the performance degradation caused by element diffusion at the two-phase interface. The prepared core-shell structured ceramic material can form an excellent microstructure of strong polarization core and high breakdown shell, which can significantly improve the polarization intensity, breakdown electric field and recoverable energy storage density of the material. It has high energy storage efficiency and low energy loss. Moreover, the raw materials of this preparation method are readily available, the process conditions are mild, and it is easy to scale up production, so it has good prospects for industrial application.

[0014] Preferably, step S10 specifically includes: S101 uses analytically pure PbO, BaCO3, La2O3, ZrO2, SnO2, and TiO2 with a purity all >99% as starting materials, according to the chemical formula (Pb 0.90 Ba 0.04 La 0.04 (Zr) 0.65 Sn 0.3 Ti 0.05 The ingredients were mixed and ball-milled in a ball mill according to the stoichiometric ratio of O3, and then dried to obtain the first dried powder. S102, the first dried powder is placed in a muffle furnace for pre-sintering for 2-4 hours to obtain pre-sintered powder; S103, the pre-calcined powder is placed in a ball mill again, mixed and ball-milled with anhydrous ethanol as the ball milling medium, and then dried to obtain the second dried powder; S104, the second dried powder is sieved to obtain PBLZST core layer powder.

[0015] Specifically, the preparation process of step S10 is highly controllable and the raw material ratio is precise, which can effectively refine the powder particle size, improve the powder purity and crystallinity, and the resulting PBLZST core layer powder has uniform particle size, good dispersibility and excellent activity.

[0016] Preferably, the conditions for ball milling in step S101 are: using zirconium balls as the ball milling medium and anhydrous ethanol as the ball milling solvent; the mass ratio of the ball milling medium, the ball milling solvent, and the starting material is 20:(1-10):(1-10), and the ball milling time is >0 and ≤36h; step S102 specifically includes: placing the first dried powder in a muffle furnace and heating it from room temperature to 600-1200℃ for pre-sintering for 2-4h, and holding it at that temperature for ≤24h, with a heating rate >0 and ≤20℃ / min; in steps S101 and S103: the drying temperature is 40-120℃, and the drying time is >0 and ≤24h; in step S104: the sieving is done through a 10-300 mesh sieve, and the material passing through the sieve is collected.

[0017] Specifically, the ball milling conditions in step S101 can fully refine the particle size of the raw material powder, ensure the uniformity of raw material mixing, and effectively avoid powder agglomeration, thereby improving the dispersibility and activity of the raw material powder. In step S102, the reasonable heating rate can prevent the powder from cracking due to thermal stress, and the appropriate pre-calcination temperature and holding time can promote the full solid-phase reaction of the raw material, improve the crystallinity and phase purity of the powder, and inhibit abnormal grain growth, ensuring the stability of the crystal phase structure of the pre-calcined powder. The drying process in steps S101 and S103 can achieve the full volatilization of anhydrous ethanol in the powder, ensuring drying efficiency while avoiding hard agglomeration of the powder due to high-temperature drying, effectively preserving the dispersibility and activity of the powder. The sieving process in step S104 further removes large-diameter particles and agglomerates, resulting in PBLZST core layer powder with uniform particle size and narrow particle size distribution, and controllable powder quality.

[0018] Preferably, step S20 specifically includes: S201, according to the chemical formula (Pb) 0.97 La 0.02 (Zr) 0.93 Sn 0.05 Ti 0.02 To prepare the first mixed solution, the following ingredients were prepared: lead acetate hydrate, lanthanum acetate hydrate, dibutyltin oxide, zirconium propoxide, and isopropyl titanate. Then, lead acetate hydrate, lanthanum acetate hydrate, and dibutyltin oxide were dissolved in 10-15 mL of acetic acid and stirred at 110 °C at a stirring rate of 400-600 rpm for 30-60 min. S202, after the first mixed solution is cooled to room temperature, zirconium propoxide, isopropyl titanate and water are added in sequence, and the mixture is stirred at a stirring rate of 400-600 rpm for 30-60 min at room temperature to obtain the second mixed solution. S203, lactic acid, ethylene glycol and n-propanol are added sequentially to the second mixed solution, and the mixture is stirred at room temperature for 30-60 min to obtain PLZST precursor sol; S204, the PLZST precursor sol is sealed and allowed to stand for aging for 24 hours to obtain the PLZST shell sol.

[0019] Specifically, step S201 ensures thorough dissolution and uniform mixing of raw materials, accelerates the complexation reaction process, and guarantees uniform dispersion of metal ions; step S202 involves orderly feeding and stirring at room temperature, which avoids premature hydrolysis and agglomeration of raw materials, improves system uniformity, and suppresses uneven hydrolysis; step S203 involves adding a complexing agent (lactic acid and ethylene glycol) and a solvent (n-propanol) followed by stirring, which can regulate the hydrolysis and polycondensation rate, resulting in a stable and well-dispersed PLZST precursor sol with no particle agglomeration; step S204 involves aging, which improves the viscosity and stability of the sol, and the resulting PLZST shell sol has excellent coating properties, enabling uniform coating of the core powder. Preferably, in step S202: the molar ratio of lead acetate to water in the second mixed solution is 1:20; in step S203: the molar ratio of lead acetate, lactic acid and ethylene glycol in the PLZST precursor sol is 1:1:1, and the content of n-propanol is 15 mL.

[0020] Specifically, the above-mentioned proportions in step S202 can achieve precise complexation and optimization of the sol system, resulting in a stable precursor sol with good dispersibility and excellent coating activity.

[0021] Preferably, step S30 specifically includes: S301, disperse PBLZST core powder by ultrasonic-assisted method for 20-120 min, then add the dispersed PBLZST core powder dropwise to PLZST shell sol according to the stoichiometric ratio of (1-x)PBLZST-xPLZST, and stir continuously for 0-12 h to fully coat the surface of PBLZST core powder with PLZST shell sol to form a core-shell structure coating material. Then place it in a forced-air drying oven and dry at a constant temperature of 200-300℃ for 12-24 h to obtain a dry gel. S302, the dry gel is placed in a muffle furnace and thermally decomposed at a temperature of 600-700℃ for 4-6 hours to obtain a (1-x)PBLZST-xPLZST core-shell structured composite powder; S303, a binder is added to the composite powder and granulation is carried out. The powder is then subjected to pre-pressing and cold isostatic pressing processes to obtain a ceramic green body. S304 involves sintering a ceramic green body at 600–1300℃ and holding it at that temperature for ≤24 hours. After sintering, the green body is allowed to cool naturally in the furnace to obtain a PZT-based energy storage ceramic material with a core-shell structure.

[0022] Specifically, the ultrasonic dispersion in step S301 deagglomerates the PBLZST core powder, and the dropwise feeding and stirring achieve uniform shell coating. The constant temperature drying gently removes the solvent, ensuring the integrity of the dry gel core-shell structure. The thermal decomposition at 600-700℃ in step S302 fully removes residual organic matter, initially promotes crystal phase formation, and retains the core-shell structure, improving the purity and dispersibility of the composite powder. The granulation in step S303 improves the powder flowability, and the ceramic green body obtained by pre-pressing and cold isostatic pressing is dense, uniform, and without obvious defects. The appropriate sintering temperature range and holding time in step S304 promote the densification of the ceramic green body and the shaping of the core and shell. The furnace cooling relieves thermal stress and avoids cracking. The final PZT-based energy storage ceramic material has high density and excellent performance.

[0023] Thirdly, the present invention also provides an application of PZT-based energy storage ceramic material with the core-shell structure described above in pulse power devices.

[0024] Specifically, this PZT-based energy storage ceramic material combines high polarization intensity, high breakdown electric field, and high recoverable energy storage density. It has high energy storage efficiency, low energy loss, and excellent temperature stability, which can fully meet the application requirements of lightweight and integrated dielectric capacitors in pulse power devices. It has good practical application value and industrialization prospects.

[0025] The beneficial effects of this invention are as follows: Unlike existing technologies, this invention provides a core-shell structured PZT-based energy storage ceramic material, its preparation method, and its applications. This PZT-based energy storage ceramic material possesses both high polarization intensity and high breakdown electric field. It is prepared by coating PBLZST tetragonal phase powder prepared by a solid-state method with PLZST orthorhombic sol prepared using a sol-gel method. After high-temperature sintering, the ceramic grains form a core-shell microstructure with a strongly polarized core and a high-breakdown shell. The polarization intensity of the PZT-based energy storage ceramic material prepared by this invention can reach 35–55 μC / cm. 2 The breakdown electric field is approximately 350–400 kV / cm. The core-shell microstructure promotes a simultaneous increase in the material's polarization intensity and breakdown electric field. Therefore, the energy storage performance of PZT-based energy storage ceramic materials is significantly improved at room temperature, with a recoverable energy storage density reaching approximately 8.96 J / cm³. 3 . Attached Figure Description

[0026] Figure 1 This is a flowchart illustrating the preparation method of the core-shell structured PZT-based energy storage ceramic materials provided in Examples 1-3. Figure 2 Hysteresis loop images of PZT-based energy storage ceramic materials provided in Examples 1-3 and Comparative Example 1; Figure 3 The images show the XRD patterns of the PZT-based energy storage ceramic materials provided in Examples 1-3 and Comparative Example 1. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0028] To address the aforementioned shortcomings in existing technologies, this study innovatively proposes a method to achieve a core-shell structure by coating another antiferroelectric lead-based powder with similar composition and structure using an antiferroelectric lead-based sol. This process offers significant advantages in interfacial bonding, compositional uniformity, microstructure control, performance synergy, and reduced sintering temperature. Furthermore, it leverages the molecular-level dispersion characteristics of the sol to compensate for the inherent defects in the physical mixing of solid-phase powders, avoiding the thermal expansion mismatch caused by particle size differences in traditional solid-phase methods.

[0029] To achieve the above objectives, this invention provides a core-shell structured PZT (Lead Zirconate Titanate)-based energy storage ceramic material, its preparation method, and its applications. From a theoretical perspective, a microstructure control strategy is proposed. This involves using a sol-gel method to prepare an orthorhombic PLZST (Lead Lanthanum Zirconate Stannate Titanate) sol to coat PBLZST (Lead Barium Lanthanum Zirconate Stannate Titanate) tetragonal phase powder prepared by a solid-state method. This results in the formation of a core-shell microstructure with a strongly polarized core and a high breakdown shell in the ceramic grains, synergistically improving the polarization intensity and breakdown electric field of the ceramic material.

[0030] Specifically, this invention provides a method for simultaneously improving the polarization intensity and breakdown electric field of PZT-based energy storage ceramic materials. In a preferred embodiment, when x=0.2, the 0.8PBLZST-0.2PLZST ceramic material exhibits high polarization intensity (30-40 μC / cm). 2 High breakdown electric field (350–400 kV / cm) and high energy storage density (8.96 J / cm²) 3 ), suitable for making pulse power devices.

[0031] The technical solution of the present invention will now be further described with reference to specific embodiments.

[0032] Example 1 (0.8PBLZST-0.2PLZST sample): 0.8(Pb 0.90 Ba 0.04 La 0.04 (Zr) 0.65 Sn 0.3 Ti 0.05 O3-0.2(Pb) 0.97 La 0.02 (Zr) 0.93 Sn 0.05 Ti 0.02 Preparation of O3 energy storage ceramic materials, preparation methods (e.g.) Figure 1 (As shown) includes the following steps: (1) According to the stoichiometric ratio, 0.8 (Pb 0.90 Ba 0.04 La 0.04 (Zr) 0.65 Sn 0.3 Ti 0.05Weigh out 0.1 mol of the required raw materials: PbO (16.86 g, lead excess 6 wt%), BaCO3 (0.63 g), La2O3 (1.04 g), ZrO2 (6.34 g), SnO2 (3.60 g), and TiO2 (0.32 g). Mix all raw materials uniformly using a wet ball milling process. The mass ratio of milling media, anhydrous ethanol, and milling powder is 8:4:3. The milling time is 24 hours. Zirconia balls are used as the milling media, and anhydrous ethanol is used as the milling solvent. The milled powder is dried at 80℃ for 12 hours.

[0033] (2) The powder dried in step (1) is pre-fired in a muffle furnace at 850°C for 3 hours.

[0034] (3) The powder pre-fired in step (2) is ball-milled again for 24 hours to obtain ceramic slurry.

[0035] (4) Dry the ceramic slurry from step (3) and pass it through an 80-mesh sieve to obtain 0.8(Pb). 0.90 Ba 0.04 La 0.04 (Zr) 0.65 Sn 0.3 Ti 0.05 )O3 core layer powder.

[0036] (5) Weigh 0.1 mol of 0.2 mol of Pb according to the stoichiometric ratio. 0.97 La 0.02 (Zr) 0.93 Sn 0.05 Ti 0.02 The required amounts of lead acetate hydrate (7.62 g, lead excess 3 wt%), lanthanum acetate hydrate (0.13 g), dibutyltin oxide (0.25 g), zirconium propoxide (8.70 g), isopropyl titanate (0.12 g), deionized water (6.98 g), lactic acid (2.06 g), and ethylene glycol (1.23 g) were prepared by dissolving lead acetate hydrate, lanthanum acetate hydrate, and dibutyltin oxide in 15 mL of acetic acid and stirring at 110 °C for 40 min at a stirring rate of 600 rpm.

[0037] (6) After cooling the solution obtained in step (5) to room temperature, zirconium propoxide, isopropyl titanate and water are added to it in sequence and stirred at room temperature for 40 minutes, wherein the stirring speed is 600 rpm.

[0038] (7) Add lactic acid and ethylene glycol to the solution obtained in step (6) in sequence, and then add 15 mL of n-propanol. Stir at room temperature for 60 min.

[0039] (8) After sealing the sol obtained in step (7), age it for 24 hours to obtain 0.2 (Pb)0.97 La 0.02 (Zr) 0.93 Sn 0.05 Ti 0.02 O3 shell sol.

[0040] (9) The 0.8(Pb) obtained in step (4) 0.90 Ba 0.04 La 0.04 (Zr) 0.65 Sn 0.3 Ti 0.05 After the O3 core layer powder was ultrasonically dispersed for 100 min using an ultrasonic-assisted method, it was added dropwise to the 0.2 (Pb) powder prepared in step (8). 0.97 La 0.02 (Zr) 0.93 Sn 0.05 Ti 0.02 In the O3 sol, continue stirring for 12 hours until the PLZST sol fully coats the surface of the PBLZST powder to form a core-shell structure. Then, place it in a forced-air drying oven at a constant temperature of 300℃ for 24 hours to obtain a dry gel.

[0041] (10) The dry gel obtained in step (9) was thermally decomposed in a muffle furnace at 700℃ for 5 hours to obtain 0.8(Pb) 0.90 Ba 0.04 La 0.04 (Zr) 0.65 Sn 0.3 Ti 0.05 O3-0.2(Pb) 0.97 La 0.02 (Zr) 0.93 Sn 0.05 Ti 0.02 O3 core-shell structure ceramic powder.

[0042] (11) Pass the powder obtained in step (10) through an 80-mesh sieve, add 10% of the ceramic powder mass of binder, the binder being a 4%~5% polyvinyl alcohol aqueous solution, granulate, and sieve.

[0043] (12) The ceramic powder obtained in step (11) is pre-pressed through a mold at a pressure of 4 MPa and a holding time of 10 seconds, and then the ceramic green body is obtained by cold isostatic pressing.

[0044] (13) The ceramic green body obtained in step (12) is sintered by first heating it to 600℃ at a rate of 5℃ / min and holding it for 30min, then heating it to 1250℃ at a rate of 2.5℃ / min and holding it for 3h, and then cooling it to room temperature in the furnace to obtain 0.8(Pb). 0.90 Ba 0.04 La0.04 (Zr) 0.65 Sn 0.3 Ti 0.05 O3-0.2(Pb) 0.97 La 0.02 ) (Zr 0.93 Sn 0.05 Ti 0.02 O3 energy storage ceramic materials.

[0045] Specifically, the hysteresis loop diagram of the PZT-based energy storage ceramic material (0.8PBLZST-0.2PLZST sample) obtained in Example 1 is as follows: Figure 2 As shown, the XRD (X-ray Diffraction) pattern is as follows: Figure 3 As shown.

[0046] Example 2 (0.6PBLZST-0.4PLZST samples): 0.6(Pb 0.90 Ba 0.04 La 0.04 (Zr) 0.65 Sn 0.3 Ti 0.05 O3-0.4(Pb) 0.97 La 0.02 (Zr) 0.93 Sn 0.05 Ti 0.02 The preparation of O3 energy storage ceramic materials includes the following steps: (1) According to the stoichiometric ratio, 0.6 (Pb 0.90 Ba 0.04 La 0.04 (Zr) 0.65 Sn 0.3 Ti 0.05 Weigh out 0.1 mol of the required amount of PbO (12.65 g, lead excess 6 wt%), BaCO3 (0.47 g), La2O3 (0.78 g), ZrO2 (4.76 g), SnO2 (2.70 g), and TiO2 (0.24 g) and prepare the mixture accordingly. Use a wet ball milling process to mix all raw materials evenly. Dry the slurry.

[0047] (2) 0.6(Pb) 0.90 Ba 0.04 La 0.04 (Zr) 0.65 Sn 0.3 Ti 0.05 The O3 core layer powder was prepared according to steps (2) to (4) in Example 1.

[0048] (3) Weigh 0.1 mol of 0.4 mol of Pb according to the stoichiometric ratio. 0.97 La 0.02 (Zr) 0.93 Sn 0.05 Ti 0.02 The raw materials required for O3 preparation were: lead acetate hydrate (15.24g, lead excess 3wt%), lanthanum acetate hydrate (0.26g), dibutyltin oxide (0.50g), zirconium propoxide (17.40g), isopropyl titanate (0.24g), deionized water (13.96g), lactic acid (4.12g), and ethylene glycol (2.46g).

[0049] (4) 0.4(Pb) 0.97 La 0.02 (Zr) 0.93 Sn 0.05 Ti 0.02 The O3 shell sol was prepared according to steps (5) to (8) in Example 1.

[0050] (5) The 0.6(Pb) obtained in step (2) 0.90 Ba 0.04 La 0.04 (Zr) 0.65 Sn 0.3 Ti 0.05 The O3 core layer powder was ultrasonically dispersed using an ultrasonic-assisted method and then added dropwise to the 0.4 (Pb) powder prepared in step (4). 0.97 La 0.02 (Zr) 0.93 Sn 0.05 Ti 0.02 In O3 sol.

[0051] (6) 0.6(Pb) 0.90 Ba 0.04 La 0.04 (Zr) 0.65 Sn 0.3 Ti 0.05 O3-0.4(Pb) 0.97 La 0.02 (Zr) 0.93 Sn 0.05 Ti 0.02 The O3 ceramic green body was prepared according to steps (9) to (12) in Example 1.

[0052] (7) The ceramic green body obtained in step (6) is sintered by first heating it to 600℃ at a rate of 5℃ / min and holding it for 30min, then heating it to 1250℃ at a rate of 2.5℃ / min and holding it for 3h, and then cooling it to room temperature in the furnace to obtain 0.6(Pb). 0.90 Ba 0.04La 0.04 (Zr) 0.65 Sn 0.3 Ti 0.05 O3-0.4(Pb) 0.97 La 0.02 (Zr) 0.93 Sn 0.05 Ti 0.02 O3 energy storage ceramic materials.

[0053] Specifically, the hysteresis loop diagram of the PZT-based energy storage ceramic material (0.6PBLZST-0.4PLZST sample) obtained in Example 2 is as follows: Figure 2 As shown, the XRD pattern is as follows Figure 3 As shown.

[0054] Example 3 (0.4PBLZST-0.6PLZST samples): 0.4(Pb 0.90 Ba 0.04 La 0.04 (Zr) 0.65 Sn 0.3 Ti 0.05 O3-0.6(Pb) 0.97 La 0.02 (Zr) 0.93 Sn 0.05 Ti 0.02 The preparation of O3 energy storage ceramic materials includes the following steps: (1) According to the stoichiometric ratio, 0.4 (Pb 0.90 Ba 0.04 La 0.04 (Zr) 0.65 Sn 0.3 Ti 0.05 Weigh out 0.1 mol of the required amount of PbO (8.43 g, lead excess 6 wt%), BaCO3 (0.31 g), La2O3 (0.52 g), ZrO2 (3.17 g), SnO2 (1.80 g), and TiO2 (0.16 g) and prepare the slurry accordingly. Use a wet ball milling process to ensure all raw materials are mixed evenly. Dry the slurry.

[0055] (2) 0.4(Pb) 0.90 Ba 0.04 La 0.04 (Zr) 0.65 Sn 0.3 Ti 0.05 The O3 core layer powder was prepared according to steps (2) to (4) in Example 1.

[0056] (3) Weigh 0.1 mol of 0.6 mol of Pb according to the stoichiometric ratio.0.97 La 0.02 (Zr) 0.93 Sn 0.05 Ti 0.02 The required raw materials for O3 were prepared by measuring the amounts of lead acetate hydrate (22.86g, lead excess 3wt%), lanthanum acetate hydrate (0.39g), dibutyltin oxide (0.75g), zirconium propoxide (26.1g), isopropyl titanate (0.36g), deionized water (20.94g), lactic acid (6.18g), and ethylene glycol (3.69g).

[0057] (4) 0.6(Pb) 0.97 La 0.02 (Zr) 0.93 Sn 0.05 Ti 0.02 The O3 shell sol was prepared according to steps (5) to (8) in Example 1.

[0058] (5) The 0.4(Pb) obtained in step (2) 0.90 Ba 0.04 La 0.04 (Zr) 0.65 Sn 0.3 Ti 0.05 The O3 core layer powder was ultrasonically dispersed using an ultrasonic-assisted method and then added dropwise to the 0.6(Pb) powder prepared in step (4). 0.97 La 0.02 (Zr) 0.93 Sn 0.05 Ti 0.02 In O3 sol.

[0059] (6) 0.6(Pb) 0.90 Ba 0.04 La 0.04 (Zr) 0.65 Sn 0.3 Ti 0.05 O3-0.4(Pb) 0.97 La 0.02 (Zr) 0.93 Sn 0.05 Ti 0.02 The O3 ceramic green body was prepared according to steps (9)-(12) in Example 1.

[0060] (7) The ceramic green body obtained in step (6) is sintered by first heating it to 600℃ at a rate of 5℃ / min and holding it for 30min, then heating it to 1250℃ at a rate of 2.5℃ / min and holding it for 3h, and then cooling it to room temperature in the furnace to obtain 0.4(Pb). 0.90 Ba 0.04 La 0.04 (Zr)0.65 Sn 0.3 Ti 0.05 O3-0.6(Pb) 0.97 La 0.02 (Zr) 0.93 Sn 0.05 Ti 0.02 O3 energy storage ceramic materials.

[0061] Specifically, the hysteresis loop diagram of the PZT-based energy storage ceramic material (0.4PBLZST-0.6PLZST samples) obtained in Example 3 is as follows: Figure 2 As shown, the XRD pattern is as follows Figure 3 As shown.

[0062] Comparative Example 1 (PBLZST sample): Preparation of (Pb) 0.90 Ba 0.04 La 0.04 (Zr) 0.65 Sn 0.3 Ti 0.05 O3 energy storage ceramic material, including the following steps: (1) Weigh 0.1 mol of Pb according to the stoichiometric ratio. 0.90 Ba 0.04 La 0.04 (Zr) 0.65 Sn 0.3 Ti 0.05 The required raw materials for O3, namely PbO (12.65g, lead excess 6wt%), BaCO3 (0.47g), La2O3 (0.78g), ZrO2 (4.76g), SnO2 (2.70g), and TiO2 (0.24g), were prepared according to the specified amounts and mixed evenly using a wet ball milling process. The slurry was then dried.

[0063] (2)(Pb 0.90 Ba 0.04 La 0.04 (Zr) 0.65 Sn 0.3 Ti 0.05 The O3 core layer powder was prepared according to steps (2)-(4) in Example 1.

[0064] (3) Pass the ceramic powder obtained in step (2) through an 80-mesh sieve, add 10% of the ceramic powder mass of binder, which is a 4%~5% polyvinyl alcohol aqueous solution, granulate, and sieve.

[0065] (4) The ceramic powder obtained in step (3) is pre-pressed through a mold at a pressure of 4 MPa and a holding time of 10 seconds, and then the ceramic green body is obtained by cold isostatic pressing.

[0066] (5) The ceramic green body obtained in step (4) is sintered by first heating it to 600℃ at a rate of 5℃ / min and holding it for 30min, then heating it to 1250℃ at a rate of 2.5℃ / min and holding it for 3h, and then cooling it to room temperature in the furnace to obtain (Pb). 0.90 Ba 0.04 La 0.04 (Zr) 0.65 Sn 0.3 Ti 0.05 O3 energy storage ceramic materials.

[0067] Specifically, the hysteresis loop diagram of the PZT-based energy storage ceramic material obtained in Comparative Example 1 is as follows: Figure 2 As shown, the XRD pattern is as follows Figure 3 As shown.

[0068] Results analysis: The test results of the core-shell structured PZT-based energy storage ceramic materials obtained in Examples 1-3 and the PZT-based energy storage ceramic material obtained in Comparative Example 1 are as follows: Figures 2 to 3 It can be seen that the core-shell structured PZT-based energy storage ceramic material of the present invention has the following characteristics: Figure 2 The hysteresis loop images of the PZT-based energy storage ceramic materials provided in Examples 1-3 and Comparative Example 1 show that when x=0.2, 0.8(Pb 0.90 Ba 0.04 La 0.04 (Zr) 0.65 Sn 0.3 Ti 0.05 O3-0.2(Pb) 0.97 La 0.02 (Zr) 0.93 Sn 0.05 Ti 0.02 High polarization strength of O3 ceramic materials (30~40μC / cm) 2 High breakdown electric field (350~400kV / cm) and high energy storage density (8.96J / cm²). 3 ), suitable for making pulse power devices.

[0069] Figure 3 The XRD images of the PZT-based energy storage ceramic materials provided in Examples 1-3 and Comparative Example 1 show that all samples exhibit a perovskite structure. Furthermore, the ceramics with orthorhombic PLZST sol show distinct bimodal peaks in the 43°–45° range, indicating the simultaneous presence of AFE. T PBLZST and AFE (antiferroelectric tetragonal phase) O PLZST two-phase (antiferroelectric orthogonal phase).

[0070] In summary, this invention specifically relates to a PZT-based energy storage ceramic material with a core-shell structure, its preparation method, and its application. The core of the aforementioned PZT-based energy storage ceramic material with a core-shell structure is composed of PBLZST, and the shell is composed of PLZST, with the shell layer coated on the surface of the core structure in sol-gel form; wherein, the core layer material has the chemical formula (Pb). 0.90 Ba 0.04 La 0.04 (Zr) 0.65 Sn 0.3 Ti 0.05 O3, the shell material has the chemical formula (Pb) 0.97 La 0.02 (Zr) 0.93 Sn 0.05 Ti 0.02 The preparation method for the core layer material involves mixing PbO, BaCO3, La2O3, ZrO2, SnO2, and TiO2 according to the standard stoichiometry of their chemical formulas, ball milling to refine the raw materials, and then using solid-state reactions and carbonate decomposition processes such as pre-calcination and secondary ball milling to prepare a tetragonal phase core layer material with high energy storage efficiency and high polarization intensity. The preparation method for the shell layer material involves mixing C4H8O4Pb·3H2O, C6H9LaO6·1.5H2O, and C8H... 18 SnO, C 12 H 28 O4Zr, C 12 H 28 O4Ti, C3H6O3, C2H6O2, and C3H8O were used in stoichiometric ratios to prepare orthorhombic sol-gel materials with shells. A layer of orthorhombic sol-gel material with a high breakdown electric field was epitaxially coated onto a tetragonal core material exhibiting high polarization and high energy storage efficiency. This microstructure enhances the performance advantages of the core and shell layers, resulting in high breakdown electric field, high polarization, and high energy storage efficiency. Under an electric field of 400 kV / cm, the prepared PZT-based energy storage ceramic achieved a voltage of 38.63 μC / cm. 2 Maximum polarization intensity, 8.96 J / cm 3 The invention achieves a recoverable energy storage density and an energy storage efficiency of 89.60%. By constructing a core-shell microstructure, this invention provides a new approach for the design of high-energy-density PZT-based energy storage ceramic materials.

[0071] It should be noted that all the above embodiments belong to the same inventive concept, and the descriptions of each embodiment have different focuses. Where the description in a particular embodiment is not detailed, please refer to the description in other embodiments.

[0072] The above embodiments merely illustrate implementation methods of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A core-shell structured PZT-based energy storage ceramic material, characterized in that, It includes a core and a shell layer coated on the surface of the core in the form of a sol. The core is a PBLZST material and the shell layer is a PLZST material. The general chemical formula of the PZT-based energy storage ceramic material is (1-x)PBLZST-xPLZST, where 0 < x < 1.

2. The core-shell structured PZT-based energy storage ceramic material according to claim 1, characterized in that, The chemical formula of the PBLZST material is (Pb 0.90 Ba 0.04 La 0.04 (Zr) 0.65 Sn 0.3 Ti 0.05 )O3; the chemical formula of the PLZST material is (Pb 0.97 La 0.02 (Zr) 0.93 Sn 0.05 Ti 0.02 )O3.

3. The core-shell structured PZT-based energy storage ceramic material according to claim 2, characterized in that, The polarization intensity of the PZT-based energy storage ceramic material is 35–55 μC / cm. 2 The breakdown electric field is 350–400 kV / cm, and the recoverable energy storage density at room temperature is 8.96 J / cm². 3 .

4. A method for preparing a core-shell structured PZT-based energy storage ceramic material according to any one of claims 1 to 3, characterized in that, Includes the following steps: S10 is made from PbO, BaCO3, La2O3, ZrO2, SnO2 and TiO2 as raw materials, and is formulated according to the standard stoichiometric ratio of PBLZST. The raw materials are ball-milled using the traditional solid-state method to refine the powder. After pre-calcination, the powder is ball-milled again to obtain PBLZST core layer powder. S20, in the form of C4H8O4Pb·3H2O, C6H9LaO6·1.5H2O, C8H 18 SnO, C 12 H 28 O4Zr, C 12 H 28 Using O4Ti, C3H6O3, C2H6O2 and C3H8O as raw materials, the raw materials were added in an orderly manner according to the stoichiometric ratio of PLZST and subjected to sol-gel treatment to obtain PLZST shell sol. S30, the PBLZST core layer powder and the PLZST shell layer sol are stirred and mixed, and after debinding, granulation, pressing and sintering, the PZT-based energy storage ceramic material with core and shell structure is obtained.

5. The method for preparing the core-shell structured PZT-based energy storage ceramic material according to claim 4, characterized in that, The S10 step specifically includes: S101 uses analytically pure PbO, BaCO3, La2O3, ZrO2, SnO2, and TiO2 with a purity all >99% as starting materials, according to the chemical formula (Pb 0.90 Ba 0.04 La 0.04 (Zr) 0.65 Sn 0.3 Ti 0.05 The ingredients were mixed and ball-milled in a ball mill according to the stoichiometric ratio of O3, and then dried to obtain the first dried powder. S102, the first dried powder is placed in a muffle furnace for pre-sintering for 2-4 hours to obtain pre-sintered powder; S103, the pre-calcined powder is placed in the ball mill again, mixed and ball-milled with anhydrous ethanol as the ball milling medium, and then dried to obtain the second dried powder; S104, the second dried powder is sieved to obtain the PBLZST core layer powder.

6. The method for preparing the core-shell structured PZT-based energy storage ceramic material according to claim 5, characterized in that, The conditions for ball milling in step S101 are as follows: zirconium balls are used as the ball milling medium and anhydrous ethanol is used as the ball milling solvent; the mass ratio of the ball milling medium, the ball milling solvent and the starting material is 20:(1~10):(1~10), and the ball milling time is >0 and ≤36h; Step S102 specifically includes: placing the first dried powder in a muffle furnace and heating it from room temperature to 600~1200℃ for pre-sintering for 2~4h, and holding it at that temperature for ≤24h, with a heating rate >0 and ≤20℃ / min; In steps S101 and S103: the drying temperature is 40~120℃, and the drying time is >0 and ≤24h; In step S104: the sieving is done through a 10~300 mesh sieve, and the material passing through the sieve is collected.

7. The method for preparing the core-shell structured PZT-based energy storage ceramic material according to claim 4, characterized in that, The S20 step specifically includes: S201, according to the chemical formula (Pb) 0.97 La 0.02 (Zr) 0.93 Sn 0.05 Ti 0.02 To prepare the first mixed solution, the following ingredients were prepared: lead acetate hydrate, lanthanum acetate hydrate, dibutyltin oxide, zirconium propoxide, and isopropyl titanate. Then, lead acetate hydrate, lanthanum acetate hydrate, and dibutyltin oxide were dissolved in 10-15 mL of acetic acid and stirred at 110 °C at a stirring rate of 400-600 rpm for 30-60 min. S202, after the first mixed solution is cooled to room temperature, zirconium propoxide, isopropyl titanate and water are added in sequence, and the mixture is stirred at a stirring rate of 400-600 rpm for 30-60 minutes at room temperature to obtain the second mixed solution. S203, lactic acid, ethylene glycol and n-propanol are added sequentially to the second mixed solution, and the mixture is stirred at room temperature for 30-60 min to obtain PLZST precursor sol; S204, the PLZST precursor sol is sealed and allowed to stand for aging for 24 hours to obtain the PLZST shell sol.

8. The method for preparing the core-shell structured PZT-based energy storage ceramic material according to claim 7, characterized in that, In step S202: the molar ratio of lead acetate to water in the second mixed solution is 1:20; in step S203: the molar ratio of lead acetate, lactic acid and ethylene glycol in the PLZST precursor sol is 1:1:1, and the content of n-propanol is 15 mL.

9. The method for preparing the core-shell structured PZT-based energy storage ceramic material according to claim 4, characterized in that, The S30 step specifically includes: S301, the PBLZST core layer powder is dispersed by ultrasonic-assisted method for 20-120 min, and then the dispersed PBLZST core layer powder is added dropwise to the PLZST shell layer sol according to the stoichiometric ratio of (1-x)PBLZST-xPLZST. The mixture is stirred continuously for 0-12 h to fully coat the surface of the PBLZST core layer powder with the PLZST shell layer sol to form a core-shell structure coating material. The material is then placed in a forced-air drying oven and dried at a constant temperature of 200-300℃ for 12-24 h to obtain a dry gel. S302, the dry gel is placed in a muffle furnace and thermally decomposed at a temperature of 600-700℃ for 4-6 hours to obtain a (1-x)PBLZST-xPLZST core-shell structured composite powder. S303, a binder is added to the composite powder and granulation is performed. The powder is then subjected to pre-pressing and cold isostatic pressing processes to obtain a ceramic green body. S304, the ceramic green body is sintered at 600-1300℃ and held for ≤24h. After sintering, it is naturally cooled in the furnace to obtain the PZT-based energy storage ceramic material with a core-shell structure.

10. The application of a core-shell structured PZT-based energy storage ceramic material according to any one of claims 1 to 3 in pulse power devices.

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