A flexible capacitor film with high energy storage properties, its preparation method and application

Abstract

This invention discloses a flexible high-energy-storage capacitor film, its preparation method, and its application, belonging to the field of dielectric thin-film capacitor preparation technology. The purpose of this invention is to solve the problem of low energy storage performance in existing capacitor films. The flexible high-energy-storage capacitor film is composed of an antiferroelectric layer material and a relaxation layer material; the antiferroelectric layer material is lead zirconate (PbZrO3, PZO), and the relaxation layer material is lead lanthanum zirconate titanate (Pb). 0.9 La 0.1 Zr 0.52 Ti 0.48 O3, PLZT); This invention studies the heat treatment temperature of antiferroelectric layer and relaxor layer materials, and further designs heterogeneous composite films with different stacking structures; This invention uses the sol-gel method to prepare heterogeneous composite films, introduces relaxor layer materials into antiferroelectric layer materials, reduces the leakage current density of capacitor films, and improves the energy storage performance of capacitor films.

Description

Technical Field

[0001] This invention belongs to the field of dielectric thin-film capacitor preparation technology, specifically relating to a method for preparing a flexible high-energy-storage capacitor thin film and its application. Background Technology

[0002] Dielectric thin film materials possess excellent electrical and optical properties and are widely used in dielectrics, information storage, piezoelectrics, optoelectronics, and other fields. Current thin film preparation processes include sol-gel methods, chemical vapor deposition, anodic oxidation, magnetron sputtering, and spray pyrolysis. The sol-gel process is widely used due to its advantage of producing high-quality films. Antiferroelectric thin films have become a research hotspot in the field of dielectric capacitors, but they still face bottlenecks such as high leakage current density and low energy storage performance. Therefore, the fabrication of a flexible capacitor film with high energy storage characteristics is urgently needed. Summary of the Invention

[0003] The purpose of this invention is to solve the problems of high leakage current density and low energy storage performance of existing thin-film capacitors, and to provide a method for preparing and applying a flexible capacitor film with high energy storage characteristics.

[0004] To achieve the above objectives, the present invention employs the following technical solution: On one hand, this invention provides a method for preparing a flexible high-energy-storage capacitor film. The flexible high-energy-storage capacitor film is composed of an antiferroelectric layer material and a relaxation layer material, and includes the following steps: I. Preparation of lead zirconate precursor solution: Lead acetate was dissolved in ethylene glycol methyl ether and acetic acid, and the solution was heated and stirred until clear to obtain solution A. After cooling to room temperature, zirconium isopropoxide was added to solution A and stirred to obtain a lead zirconate precursor solution. II. Preparation of lead lanthanum zirconate titanate precursor solution: Acetic acid and lanthanum lead nitrate were dissolved in ethylene glycol methyl ether and acetic acid, and heated and stirred until clear to obtain solution B. After cooling to room temperature, zirconium isopropoxide and tetrabutyl titanate were added to solution B, and acetylacetone was added as a stabilizer. The mixture was stirred to obtain a lanthanum lead zirconate titanate precursor solution. III. Preparation of antiferroelectric composite thin films: Lead zirconate precursor solution and lead zirconate titanate lanthanum precursor solution were spin-coated sequentially onto a substrate. The wet film was then dried on a flat plate heater and placed in a rapid annealing furnace for heat treatment to obtain a flexible capacitor film with high energy storage characteristics.

[0005] Preferably, the antiferroelectric layer material is lead zirconate PbZrO3 (PZO), and the relaxor layer material is lead zirconate titanate Pb. 0.9 La 0.1 Zr 0.52 Ti0.48 O3 (PLZT).

[0006] Preferably, the concentration of the lead zirconate precursor solution in step one is 0.1 mol / L to 0.45 mol / L.

[0007] Preferably, the concentration of the lead lanthanum zirconate titanate precursor solution in step two is 0.1 mol / L to 0.45 mol / L.

[0008] Preferably, the heating and stirring temperature in step two is 50°C to 70°C; the substrate in step three is a flexible mica substrate.

[0009] Preferably, the order of spin-coating the precursors on the substrate in step three is PZO (lead zirconate), PLZT (lead lanthanum zirconate titanate), PLPLP (1 layer of lead zirconate / 1 layer of lead lanthanum zirconate titanate / 2 layers of lead zirconate / 1 layer of lead lanthanum zirconate titanate / 1 layer of lead zirconate), PLP (2 layers of lead zirconate / 2 layers of lead lanthanum zirconate titanate / 2 layers of lead zirconate), PL (1 layer of lead zirconate / 1 layer of lead lanthanum zirconate titanate / 1 layer of lead zirconate / 1 layer of lead lanthanum zirconate titanate / 1 layer of lead zirconate / 1 layer of lead lanthanum zirconate titanate), LP (1 layer of lead lanthanum zirconate titanate / 1 layer of lead zirconate / 1 layer of lead lanthanum zirconate titanate / 1 layer of lead zirconate / 1 layer of lead lanthanum zirconate titanate / 1 layer of lead zirconate).

[0010] Preferably, the drying temperature in step three is 350℃~450℃.

[0011] Preferably, the heat treatment temperature in step three is 550~750℃.

[0012] Preferably, the protective gas for the heat treatment environment in step three is oxygen.

[0013] On the other hand, the present invention provides an application of a flexible high-energy-storage capacitor film, which is used in film capacitors.

[0014] Compared with the prior art, the present invention has the following beneficial effects: I. This invention uses a sol-gel method combined with spin-coating annealing to prepare a flexible capacitor film with high energy storage characteristics; by introducing a relaxor layer material into the antiferroelectric layer material, the leakage current density of the capacitor film is reduced and the energy storage performance of the capacitor film is improved. II. The flexible high-energy-storage capacitor film prepared by this invention can be used as a film capacitor. It has a low leakage current density and high energy storage performance, and is suitable for the design of functional devices and the manufacture of flexible electronic devices. Third, the preparation process of the flexible high-energy-storage capacitor film provided by this invention is simple, the equipment is inexpensive, and the selected materials are environmentally friendly and pollution-free, making it suitable for large-scale production. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope.

[0016] Figure 1 X-ray diffraction patterns of the flexible high-energy-storage capacitor films prepared in Examples 1-5; Figure 2 Atomic force microscopy images of the flexible high-energy-storage capacitor films prepared in Examples 1-5; Figure 3 Hysteresis loop diagrams of the flexible high-energy-storage capacitor films prepared in Examples 1-5; Figure 4 The breakdown field strength diagrams are for the flexible high-energy-storage capacitor films prepared in Examples 1-5. Figure 5 Leakage current diagrams of the flexible high-energy-storage capacitor films prepared in Examples 1-3; Figure 6 The energy storage performance diagrams are for the flexible high-energy-storage capacitor films prepared in Examples 1-5. Figure 7 X-ray diffraction patterns of the flexible high-energy-storage capacitor films prepared in Examples 6-10; Figure 8 Atomic force microscopy images of the flexible high-energy-storage capacitor films prepared in Examples 6-10; Figure 9 Hysteresis loop diagrams of the flexible high-energy-storage capacitor films prepared in Examples 6-10; Figure 10 The breakdown field strength diagrams are for the flexible high-energy-storage capacitor films prepared in Examples 6-10; Figure 11 Leakage current diagrams of the flexible high-energy-storage capacitor films prepared in Examples 6-10; Figure 12 The energy storage performance diagrams are for the flexible high-energy-storage capacitor films prepared in Examples 6-10. Figure 13 X-ray diffraction patterns of the flexible high-energy-storage capacitor films prepared in Examples 11-13 and Comparative Examples 1-2; Figure 14 Atomic force microscopy images of the flexible high-energy-storage capacitor films prepared in Examples 11-13 and Comparative Examples 1-2; Figure 15 Hysteresis loop diagrams of the flexible high-energy-storage capacitor films prepared in Examples 11-13 and Comparative Examples 1-2; Figure 16The breakdown field strength diagrams are for the flexible high-energy-storage capacitor films prepared in Examples 11-13 and Comparative Examples 1-2. Figure 17 Leakage current diagrams of the flexible high-energy-storage capacitor films prepared in Examples 11-13 and Comparative Examples 1-2; Figure 18 The diagram shows the energy storage performance of the flexible high-energy-storage capacitor films prepared in Examples 11-13 and Comparative Examples 1-2. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0018] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0019] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials, reagents, methods, and instruments used are all conventional materials, reagents, methods, and instruments in the art, and can be obtained commercially by those skilled in the art.

[0020] Specific Implementation Method 1: This implementation method provides a flexible high-energy-storage capacitor film, characterized in that the high-energy-storage capacitor film is composed of an antiferroelectric layer material and a relaxation layer material; the antiferroelectric layer material is lead zirconate (PbZrO3, PZO), and the relaxation layer material is lead lanthanum zirconate titanate (Pb). 0.9 La 0.1 Zr 0.52 Ti 0.48 O3, PLZT).

[0021] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the preparation method of the flexible high-energy-storage capacitor film is characterized by being completed according to the following steps: I. Preparation of lead zirconate precursor solution: Lead acetate was dissolved in ethylene glycol methyl ether and acetic acid, and the solution was heated and stirred until clear to obtain solution A. After cooling to room temperature, zirconium isopropoxide was added to solution A and stirred to obtain a lead zirconate precursor solution. II. Preparation of lead lanthanum zirconate titanate precursor solution: Acetic acid and lanthanum lead nitrate were dissolved in ethylene glycol methyl ether and acetic acid, and heated and stirred until clear to obtain solution B. After cooling to room temperature, zirconium isopropoxide and tetrabutyl titanate were added to solution B, and acetylacetone was added as a stabilizer. The mixture was stirred to obtain a lanthanum lead zirconate titanate precursor solution. III. Preparation of antiferroelectric composite thin films: Lead zirconate precursor solution and lead zirconate titanate lanthanum precursor solution were spin-coated sequentially onto a substrate. The wet film was then dried on a flat plate heater and placed in a rapid annealing furnace for heat treatment to obtain a flexible capacitor film with high energy storage characteristics.

[0022] Specific Implementation Method 3: The difference between this implementation method and Specific Implementation Method 1 or 2 is that the concentration of the lead zirconate precursor solution mentioned in step 1 is 0.1 mol / L to 0.45 mol / L.

[0023] Specific Implementation Method Four: The difference between this implementation method and Specific Implementation Methods One to Three is that the concentration of the lead lanthanum zirconate titanate precursor solution mentioned in step two is 0.1 mol / L to 0.45 mol / L.

[0024] Specific Implementation Method 5: The difference between this implementation method and Specific Implementation Methods 1 to 4 is that the heating and stirring temperature in step 2 is 50℃~70℃; the substrate in step 3 is a flexible mica substrate.

[0025] Specific Implementation Method Six: The difference between this implementation method and Specific Implementation Methods One to Five is that the order of spin-coating the precursor on the substrate in step three is PZO (lead zirconate), PLZT (lead lanthanum zirconate titanate), PLPLP (1 layer of lead zirconate / 1 layer of lead lanthanum zirconate titanate / 2 layers of lead zirconate / 1 layer of lead lanthanum zirconate titanate / 1 layer of lead zirconate), PLP (2 layers of lead zirconate / 2 layers of lead lanthanum zirconate titanate / 2 layers of lead zirconate), PL (1 layer of lead zirconate / 1 layer of lead lanthanum zirconate titanate / 1 layer of lead zirconate / 1 layer of lead lanthanum zirconate titanate / 1 layer of lead zirconate / 1 layer of lead lanthanum zirconate titanate), LP (1 layer of lead lanthanum zirconate titanate / 1 layer of lead zirconate / 1 layer of lead lanthanum zirconate titanate / 1 layer of lead zirconate / 1 layer of lead lanthanum zirconate titanate / 1 layer of lead zirconate).

[0026] Specific Implementation Method Seven: The difference between this implementation method and Specific Implementation Methods One to Six is ​​that the drying temperature in step three is 350℃~450℃.

[0027] Specific Implementation Method Eight: The difference between this implementation method and Specific Implementation Methods One to Seven is that the heat treatment temperature in step three is 550~750℃.

[0028] Specific Implementation Method Nine: The difference between this implementation method and Specific Implementation Methods One to Eight is that the protective gas for the heat treatment environment described in step three is oxygen.

[0029] Specific Implementation Method 10: This implementation method is an application of a flexible high-energy-storage capacitor film in a film capacitor.

[0030] The beneficial effects of the present invention are verified using the following embodiments: Example 1: A flexible high-energy-storage capacitor film, wherein the high-energy-storage capacitor film is composed of a lead zirconate layer composite, and the preparation method is specifically carried out according to the following steps: I. Preparation of lead zirconate precursor solution: Lead acetate was dissolved in ethylene glycol methyl ether and acetic acid, and heated and stirred at 60°C until clear to obtain solution A; after cooling to room temperature, zirconium isopropoxide was added to solution A and stirred to obtain lead zirconate precursor solution; The concentration of the lead zirconate precursor solution mentioned in step one is 0.3 mol / L; II. Preparation of capacitor thin films with high energy storage characteristics: Six layers of lead zirconate precursor solution were spin-coated onto a substrate, and then the wet film was dried on a flat plate heater and then placed in a rapid annealing furnace for rapid annealing to obtain a high-energy-storage capacitor film (PZO). The substrate mentioned in step two is a mica substrate; The drying temperature described in step two is 450℃; The annealing temperature described in step two is 550°C.

[0031] Example 2: A flexible high-energy-storage capacitor film, wherein the high-energy-storage capacitor film is composed of a lead zirconate layer composite, and the preparation method is specifically carried out according to the following steps: I. Preparation of lead zirconate precursor solution: Lead acetate was dissolved in ethylene glycol methyl ether and acetic acid, and heated and stirred at 60°C until clear to obtain solution A; after cooling to room temperature, zirconium isopropoxide was added to solution A and stirred to obtain lead zirconate precursor solution; The concentration of the lead zirconate precursor solution mentioned in step one is 0.3 mol / L; II. Preparation of capacitor thin films with high energy storage characteristics: Six layers of lead zirconate precursor solution were spin-coated onto a substrate, and then the wet film was dried on a flat plate heater and then placed in a rapid annealing furnace for rapid annealing to obtain a high-energy-storage capacitor film (PZO). The substrate mentioned in step two is a mica substrate; The drying temperature described in step two is 450℃; The annealing temperature described in step two is 600℃.

[0032] Example 3: A flexible high-energy-storage capacitor film, wherein the high-energy-storage capacitor film is composed of a lead zirconate layer composite, and the preparation method is specifically carried out according to the following steps: I. Preparation of lead zirconate precursor solution: Lead acetate was dissolved in ethylene glycol methyl ether and acetic acid, and heated and stirred at 60°C until clear to obtain solution A; after cooling to room temperature, zirconium isopropoxide was added to solution A and stirred to obtain lead zirconate precursor solution; The concentration of the lead zirconate precursor solution mentioned in step one is 0.3 mol / L; II. Preparation of capacitor thin films with high energy storage characteristics: Six layers of lead zirconate precursor solution were spin-coated onto a substrate, and then the wet film was dried on a flat plate heater and then placed in a rapid annealing furnace for rapid annealing to obtain a high-energy-storage capacitor film (PZO). The substrate mentioned in step two is a mica substrate; The drying temperature described in step two is 450℃; The annealing temperature described in step two is 650°C.

[0033] Example 4: A flexible high-energy-storage capacitor film, wherein the high-energy-storage capacitor film is composed of a lead zirconate layer composite, and the preparation method is specifically carried out according to the following steps: I. Preparation of lead zirconate precursor solution: Lead acetate was dissolved in ethylene glycol methyl ether and acetic acid, and heated and stirred at 60°C until clear to obtain solution A; after cooling to room temperature, zirconium isopropoxide was added to solution A and stirred to obtain lead zirconate precursor solution; The concentration of the lead zirconate precursor solution mentioned in step one is 0.3 mol / L; II. Preparation of capacitor thin films with high energy storage characteristics: Six layers of lead zirconate precursor solution were spin-coated onto a substrate, and then the wet film was dried on a flat plate heater and then placed in a rapid annealing furnace for rapid annealing to obtain a high-energy-storage capacitor film (PZO). The substrate mentioned in step two is a mica substrate; The drying temperature described in step two is 450℃; The annealing temperature described in step two is 700℃.

[0034] Example 5: A flexible high-energy-storage capacitor film, wherein the high-energy-storage capacitor film is composed of a lead zirconate layer composite, and the preparation method is specifically carried out according to the following steps: I. Preparation of lead zirconate precursor solution: Lead acetate was dissolved in ethylene glycol methyl ether and acetic acid, and heated and stirred at 60°C until clear to obtain solution A; after cooling to room temperature, zirconium isopropoxide was added to solution A and stirred to obtain lead zirconate precursor solution; The concentration of the lead zirconate precursor solution mentioned in step one is 0.3 mol / L; II. Preparation of capacitor thin films with high energy storage characteristics: Six layers of lead zirconate precursor solution were spin-coated onto a substrate, and then the wet film was dried on a flat plate heater and then placed in a rapid annealing furnace for rapid annealing to obtain a high-energy-storage capacitor film (PZO). The substrate mentioned in step two is a mica substrate; The drying temperature described in step two is 450℃; The annealing temperature described in step two is 750°C.

[0035] Example 6: A flexible high-energy-storage capacitor film, wherein the high-energy-storage capacitor film is composed of a lead-lanthanum zirconate titanate composite layer, and the preparation method is specifically carried out according to the following steps: I. Preparation of lead lanthanum zirconate titanate precursor solution: Acetic acid and lanthanum lead nitrate were dissolved in ethylene glycol methyl ether and acetic acid, and heated and stirred at 60°C until clear to obtain solution B. After cooling to room temperature, zirconium isopropoxide and tetrabutyl titanate were added to solution B, and acetylacetone was added as a stabilizer. The mixture was stirred to obtain a lanthanum lead zirconate titanate precursor solution. The concentration of the lead zirconate precursor solution mentioned in step one is 0.3 mol / L; II. Preparation of capacitor thin films with high energy storage characteristics: Six layers of lead lanthanum zirconate titanate precursor solution were spin-coated onto a substrate. The wet film was then dried on a flat plate heater and placed in a rapid annealing furnace for rapid annealing to obtain a high energy storage capacitor film (PLZT). The substrate mentioned in step two is a mica substrate; The drying temperature described in step two is 450℃; The annealing temperature described in step two is 550°C.

[0036] Example 7: A flexible high-energy-storage capacitor film, wherein the high-energy-storage capacitor film is composed of a lead-lanthanum zirconate titanate layer, and the preparation method is specifically carried out according to the following steps: I. Preparation of lead lanthanum zirconate titanate precursor solution: Acetic acid and lanthanum lead nitrate were dissolved in ethylene glycol methyl ether and acetic acid, and heated and stirred at 60°C until clear to obtain solution B. After cooling to room temperature, zirconium isopropoxide and tetrabutyl titanate were added to solution B, and acetylacetone was added as a stabilizer. The mixture was stirred to obtain a lanthanum lead zirconate titanate precursor solution. The concentration of the lead zirconate precursor solution mentioned in step one is 0.3 mol / L; II. Preparation of capacitor thin films with high energy storage characteristics: Six layers of lead lanthanum zirconate titanate precursor solution were spin-coated onto a substrate. The wet film was then dried on a flat plate heater and placed in a rapid annealing furnace for rapid annealing to obtain a high energy storage capacitor film (PLZT). The substrate mentioned in step two is a mica substrate; The drying temperature described in step two is 450℃; The annealing temperature described in step two is 600℃.

[0037] Example 8: A flexible high-energy-storage capacitor film, wherein the high-energy-storage capacitor film is composed of a lead-lanthanum zirconate titanate composite layer, and the preparation method is specifically carried out according to the following steps: I. Preparation of lead lanthanum zirconate titanate precursor solution: Acetic acid and lanthanum lead nitrate were dissolved in ethylene glycol methyl ether and acetic acid, and heated and stirred at 60°C until clear to obtain solution B. After cooling to room temperature, zirconium isopropoxide and tetrabutyl titanate were added to solution B, and acetylacetone was added as a stabilizer. The mixture was stirred to obtain a lanthanum lead zirconate titanate precursor solution. The concentration of the lead zirconate precursor solution mentioned in step one is 0.3 mol / L; II. Preparation of capacitor thin films with high energy storage characteristics: Six layers of lead lanthanum zirconate titanate precursor solution were spin-coated onto a substrate. The wet film was then dried on a flat plate heater and placed in a rapid annealing furnace for rapid annealing to obtain a high energy storage capacitor film (PLZT). The substrate mentioned in step two is a mica substrate; The drying temperature described in step two is 450℃; The annealing temperature described in step two is 650°C.

[0038] Example 9: A flexible high-energy-storage capacitor film, wherein the high-energy-storage capacitor film is composed of a lead-lanthanum zirconate titanate layer, and the preparation method is specifically carried out according to the following steps: I. Preparation of lead lanthanum zirconate titanate precursor solution: Acetic acid and lanthanum lead nitrate were dissolved in ethylene glycol methyl ether and acetic acid, and heated and stirred at 60°C until clear to obtain solution B. After cooling to room temperature, zirconium isopropoxide and tetrabutyl titanate were added to solution B, and acetylacetone was added as a stabilizer. The mixture was stirred to obtain a lanthanum lead zirconate titanate precursor solution. The concentration of the lead zirconate precursor solution mentioned in step one is 0.3 mol / L; II. Preparation of capacitor thin films with high energy storage characteristics: Six layers of lead lanthanum zirconate titanate precursor solution were spin-coated onto a substrate. The wet film was then dried on a flat plate heater and placed in a rapid annealing furnace for rapid annealing to obtain a high energy storage capacitor film (PLZT). The substrate mentioned in step two is a mica substrate; The drying temperature described in step two is 450℃; The annealing temperature described in step two is 700℃.

[0039] Example 10: A flexible high-energy-storage capacitor film, wherein the high-energy-storage capacitor film is composed of a lead-lanthanum zirconate titanate composite layer, and the preparation method is specifically carried out according to the following steps: I. Preparation of lead lanthanum zirconate titanate precursor solution: Acetic acid and lanthanum lead nitrate were dissolved in ethylene glycol methyl ether and acetic acid, and heated and stirred at 60°C until clear to obtain solution B. After cooling to room temperature, zirconium isopropoxide and tetrabutyl titanate were added to solution B, and acetylacetone was added as a stabilizer. The mixture was stirred to obtain a lanthanum lead zirconate titanate precursor solution. The concentration of the lead zirconate precursor solution mentioned in step one is 0.3 mol / L; II. Preparation of capacitor thin films with high energy storage characteristics: Six layers of lead lanthanum zirconate titanate precursor solution were spin-coated onto a substrate. The wet film was then dried on a flat plate heater and placed in a rapid annealing furnace for rapid annealing to obtain a high energy storage capacitor film (PLZT). The substrate mentioned in step two is a mica substrate; The drying temperature described in step two is 450℃; The annealing temperature described in step two is 750°C.

[0040] Example 11: A flexible high-energy-storage capacitor film, wherein the high-energy-storage capacitor film is composed of a lead zirconate layer and a lead lanthanum zirconate titanate composite, and the preparation method is specifically carried out according to the following steps: I. Preparation of lead zirconate precursor solution: Lead acetate was dissolved in ethylene glycol methyl ether and acetic acid, and heated and stirred at 60°C until clear to obtain solution A; after cooling to room temperature, zirconium isopropoxide was added to solution A and stirred to obtain lead zirconate precursor solution; The concentration of the lead zirconate precursor solution mentioned in step one is 0.3 mol / L; II. Preparation of lead lanthanum zirconate titanate precursor solution: Acetic acid and lanthanum lead nitrate were dissolved in ethylene glycol methyl ether and acetic acid, and heated and stirred at 60°C until clear to obtain solution B. After cooling to room temperature, zirconium isopropoxide and tetrabutyl titanate were added to solution B, and acetylacetone was added as a stabilizer. The mixture was stirred to obtain a lanthanum lead zirconate titanate precursor solution. The concentration of the lead zirconate precursor solution mentioned in step two is 0.3 mol / L; III. Preparation of capacitor films with high energy storage characteristics: One layer of lead zirconate / one layer of lead zirconate titanate lanthanum / two layers of lead zirconate / one layer of lead zirconate titanate lanthanum / one layer of lead zirconate precursor solution were spin-coated onto the substrate. The wet film was then dried on a flat plate heater and placed in a rapid annealing furnace for rapid annealing to obtain a high energy storage capacitor film (PLPLP). The substrate mentioned in step three is a mica substrate; The drying temperature described in step three is 450℃; The annealing temperature described in step three is 700℃.

[0041] Example 12: A flexible high-energy-storage capacitor film, wherein the high-energy-storage capacitor film is composed of a lead zirconate layer and a lead lanthanum zirconate titanate composite, and the preparation method is specifically carried out according to the following steps: I. Preparation of lead zirconate precursor solution: Lead acetate was dissolved in ethylene glycol methyl ether and acetic acid, and heated and stirred at 60°C until clear to obtain solution A; after cooling to room temperature, zirconium isopropoxide was added to solution A and stirred to obtain lead zirconate precursor solution; The concentration of the lead zirconate precursor solution mentioned in step one is 0.3 mol / L; II. Preparation of lead lanthanum zirconate titanate precursor solution: Acetic acid and lanthanum lead nitrate were dissolved in ethylene glycol methyl ether and acetic acid, and heated and stirred at 60°C until clear to obtain solution B. After cooling to room temperature, zirconium isopropoxide and tetrabutyl titanate were added to solution B, and acetylacetone was added as a stabilizer. The mixture was stirred to obtain a lanthanum lead zirconate titanate precursor solution. The concentration of the lead zirconate precursor solution mentioned in step two is 0.3 mol / L; III. Preparation of capacitor films with high energy storage characteristics: Two layers of lead zirconate / two layers of lead zirconate titanate lanthanum / two layers of lead zirconate precursor solution were spin-coated sequentially on a substrate. The wet film was then dried on a flat plate heater and placed in a rapid annealing furnace for rapid annealing to obtain a high energy storage capacitor film (PLP). The substrate mentioned in step three is a mica substrate; The drying temperature described in step three is 450℃; The annealing temperature described in step three is 700℃.

[0042] Example 13: A flexible high-energy-storage capacitor film, wherein the high-energy-storage capacitor film is composed of a lead zirconate layer and a lead lanthanum zirconate titanate composite, and the preparation method is specifically carried out according to the following steps: I. Preparation of lead zirconate precursor solution: Lead acetate was dissolved in ethylene glycol methyl ether and acetic acid, and heated and stirred at 60°C until clear to obtain solution A; after cooling to room temperature, zirconium isopropoxide was added to solution A and stirred to obtain lead zirconate precursor solution; The concentration of the lead zirconate precursor solution mentioned in step one is 0.3 mol / L; II. Preparation of lead lanthanum zirconate titanate precursor solution: Acetic acid and lanthanum lead nitrate were dissolved in ethylene glycol methyl ether and acetic acid, and heated and stirred at 60°C until clear to obtain solution B. After cooling to room temperature, zirconium isopropoxide and tetrabutyl titanate were added to solution B, and acetylacetone was added as a stabilizer. The mixture was stirred to obtain a lanthanum lead zirconate titanate precursor solution. The concentration of the lead zirconate precursor solution mentioned in step two is 0.3 mol / L; III. Preparation of capacitor films with high energy storage characteristics: One layer of lead zirconate titanate lanthanum / one layer of lead zirconate / one layer of lead zirconate titanate lanthanum / one layer of lead zirconate / one layer of lead zirconate titanate lanthanum / one layer of lead zirconate precursor solution was spin-coated onto a substrate. The wet film was then dried on a flat plate heater and placed in a rapid annealing furnace for rapid annealing to obtain a high energy storage capacitor film (LP). The substrate mentioned in step three is a mica substrate; The drying temperature described in step three is 450℃; The annealing temperature described in step three is 700℃.

[0043] Comparative Example 1: A flexible high-energy-storage capacitor film, wherein the high-energy-storage capacitor film is composed of a lead zirconate layer and a lead lanthanum zirconate titanate composite, and the preparation method is specifically carried out according to the following steps: I. Preparation of lead zirconate precursor solution: Lead acetate was dissolved in ethylene glycol methyl ether and acetic acid, and heated and stirred at 60°C until clear to obtain solution A; after cooling to room temperature, zirconium isopropoxide was added to solution A and stirred to obtain lead zirconate precursor solution; The concentration of the lead zirconate precursor solution mentioned in step one is 0.3 mol / L; II. Preparation of lead lanthanum zirconate titanate precursor solution: Acetic acid and lanthanum lead nitrate were dissolved in ethylene glycol methyl ether and acetic acid, and heated and stirred at 60°C until clear to obtain solution B. After cooling to room temperature, zirconium isopropoxide and tetrabutyl titanate were added to solution B, and acetylacetone was added as a stabilizer. The mixture was stirred to obtain a lanthanum lead zirconate titanate precursor solution. The concentration of the lead zirconate precursor solution mentioned in step two is 0.3 mol / L; III. Preparation of capacitor films with high energy storage characteristics: One layer of lead zirconate / one layer of lead zirconate titanate lanthanum / one layer of lead zirconate / one layer of lead zirconate titanate lanthanum / one layer of lead zirconate / one layer of lead zirconate titanate lanthanum precursor solution was spin-coated onto a substrate. The wet film was then dried on a flat plate heater and placed in a rapid annealing furnace for rapid annealing to obtain a high energy storage capacitor film (PL). The substrate mentioned in step three is a mica substrate; The drying temperature described in step three is 450℃; The annealing temperature described in step three is 700℃.

[0044] Comparative Example 2: A flexible high-energy-storage capacitor film, wherein the high-energy-storage capacitor film is composed of a lead zirconate layer and a lead lanthanum zirconate titanate composite, and the preparation method is specifically carried out according to the following steps: I. Preparation of lead zirconate precursor solution: Lead acetate was dissolved in ethylene glycol methyl ether and acetic acid, and heated and stirred at 60°C until clear to obtain solution A; after cooling to room temperature, zirconium isopropoxide was added to solution A and stirred to obtain lead zirconate precursor solution; The concentration of the lead zirconate precursor solution mentioned in step one is 0.3 mol / L; II. Preparation of lead lanthanum zirconate titanate precursor solution: Acetic acid and lanthanum lead nitrate were dissolved in ethylene glycol methyl ether and acetic acid, and heated and stirred at 60°C until clear to obtain solution B. After cooling to room temperature, zirconium isopropoxide and tetrabutyl titanate were added to solution B, and acetylacetone was added as a stabilizer. The mixture was stirred to obtain a lanthanum lead zirconate titanate precursor solution. The concentration of the lead zirconate precursor solution mentioned in step two is 0.3 mol / L; III. Preparation of capacitor films with high energy storage characteristics: One layer of lead zirconate / one layer of lead zirconate titanate lanthanum / one layer of lead zirconate / one layer of lead zirconate titanate lanthanum / one layer of lead zirconate / one layer of lead zirconate titanate lanthanum precursor solution was spin-coated onto a substrate. The wet film was then dried on a flat plate heater and placed in a rapid annealing furnace for rapid annealing to obtain a high energy storage capacitor film (PL). The substrate mentioned in step three is a mica substrate; The drying temperature described in step three is 450℃; The annealing temperature described in step three is 550°C.

[0045] Figure 1 X-ray diffraction patterns of the flexible high-energy-storage capacitor films prepared in Examples 1-5; from Figure 1 It can be seen that PZO crystallizes well and no pyrochlore phase or other impurities appear. As the temperature increases, the crystallinity of the film gradually increases.

[0046] Figure 2 Atomic force microscopy images of the flexible high-energy-storage capacitor films prepared in Examples 1-5; from Figure 2 It can be seen that the thin film surface is relatively smooth, without obvious pores, and its root mean square roughness (R) is... q） The wavelengths are 1.64 nm, 2.18 nm, 3.76 nm, 9.24 nm, and 12.1 nm, respectively.

[0047] Figure 3 Hysteresis loop diagrams of the flexible high-energy-storage capacitor films prepared in Examples 1-5; from Figure 3 It can be seen that PZO films annealed at 550°C and 600°C exhibit quasi-linear polarization behavior. r Its voltage is close to zero, and its breakdown voltage is relatively high because it is an amorphous thin film. When the annealing temperature reaches 650°C, the film is at the boundary between amorphous and crystalline states. As can be seen from the PE curve, the film annealed at 650°C exhibits certain ferroelectricity. When the annealing temperature reaches 700°C and above, the PE curve of the PZO film shows antiferroelectric polarization characteristics, specifically manifested by the appearance of double hysteresis loops.

[0048] Figure 4 The breakdown field strength diagrams are for the flexible high-energy-storage capacitor films prepared in Examples 1-5; from Figure 4 It can be seen that the E of PZO films annealed at 550℃, 600℃, 650℃, 700℃ and 750℃ is... b The values ​​were 3250 kV / cm, 3000 kV / cm, 1250 kV / cm, 1125 kV / cm, and 875 kV / cm, respectively. It can be seen that the breakdown field strength of the PZO film gradually decreases with the increase of annealing temperature.

[0049] Figure 5 Leakage current diagrams of the flexible high-energy-storage capacitor films prepared in Examples 1-3; from Figure 5 It is known that semi-crystalline PZO films annealed at low temperatures exhibit lower leakage current density due to their amorphous components. Crystalline films annealed at 700°C have a leakage current at least one order of magnitude higher than those annealed at 550°C.

[0050] Figure 6 The energy storage performance diagrams are for the flexible high-energy-storage capacitor films prepared in Examples 1-5. from Figure 6It can be seen that for semi-crystalline thin films annealed at low temperatures, the energy storage efficiency remains above 80%, which is related to the near-linear polarization characteristics of amorphous thin films. The energy storage efficiency decreases most rapidly for films annealed at 650°C, which is similar to the polarization characteristics of ferroelectric thin film materials. Under the same electric field strength, films treated with high-temperature annealing exhibit higher energy storage density compared to films annealed at low temperatures.

[0051] Figure 7 X-ray diffraction patterns of the flexible high-energy-storage capacitor films prepared in Examples 6-10; from Figure 7 It can be seen that the sample annealed at 750℃ exhibits sharp perovskite phase characteristic peaks. As the annealing temperature drops to 700℃ and 650℃, the intensity of the diffraction peaks gradually weakens, but the peak shape remains symmetrical, indicating that the thin film material maintains the perovskite main phase structure.

[0052] Figure 8 Atomic force microscopy images of the flexible high-energy-storage capacitor films prepared in Examples 6-10; from Figure 8 It can be seen that the thin film surface is relatively smooth, without obvious pores, and its root mean square roughness (R) is... q） The wavelengths are 0.242 nm, 0.416 nm, 0.524 nm, 1.12 nm, and 3.08 nm, respectively.

[0053] Figure 9 Hysteresis loop diagrams of the flexible high-energy-storage capacitor films prepared in Examples 6-10; from Figure 9 It can be seen that as the annealing temperature increases, the film exhibits higher P after an electric field is applied. max This is because as the annealing temperature increases, the crystallinity of the film increases, and the film transforms into a highly polarized relaxor ferroelectric. Under an external electric field, the electric domains are more likely to achieve long-range ordered flipping, thereby significantly improving the maximum polarization intensity.

[0054] Figure 10 The breakdown field strength diagrams are for the flexible high-energy-storage capacitor films prepared in Examples 6-10; from Figure 10 It can be seen that at lower annealing temperatures, the film is predominantly in a semi-crystalline / amorphous composite state, exhibiting a high breakdown field strength. As the temperature rises to 650°C, the grains begin to coarsen, and the film reaches the critical point between linearity and relaxation, with the breakdown field strength plummeting to 1375 kV / cm. When the temperature further increases to 700°C, the film exhibits the characteristics of a relaxor ferroelectric, and the breakdown field strength recovers to 1750 kV / cm.

[0055] Figure 11 Leakage current diagrams of the flexible high-energy-storage capacitor films prepared in Examples 6-10; from Figure 11 It can be seen that amorphous films exhibit lower leakage current, while films with higher crystallinity show a significant increase in leakage current.

[0056] Figure 12 The energy storage performance diagrams are for the flexible high-energy-storage capacitor films prepared in Examples 6-10. from Figure 12 It can be seen that W of the PLZT thin film near the breakdown field strength rec They were 8.9 J / cm 3 9.21 J / cm 3 19.26 J / cm 3 26.97 J / cm 3 19.48 J / cm 3 The corresponding η values ​​are 93.14%, 94.05%, 68.07%, 39.02%, and 48.02%, respectively. In summary, the PLZT thin film annealed at 700°C has the highest energy storage density.

[0057] Figure 13 X-ray diffraction patterns of the flexible high-energy-storage capacitor films prepared in Examples 11-13 and Comparative Examples 1-2; from Figure 13 It can be seen from the figure that all films except PL-550 have diffraction peaks of phases (100), (110), and (211). The absence of impurity phase formation indicates that all films have a perovskite structure. PL-550 is a composite film annealed at 550°C by PL, and it can be seen that its characteristic peaks are almost identical to those of PLZT films annealed at 550°C.

[0058] Figure 14 Atomic force microscopy images of the flexible high-energy-storage capacitor films prepared in Examples 11-13 and Comparative Examples 1-2; from Figure 14 It can be seen that: all film surfaces are flat and smooth with no obvious defects, R q The wavelengths are 3.73 nm, 4.23 nm, 2.54 nm, 1.76 nm, and 0.213 nm, respectively. This demonstrates that increasing the multilayer interface structure, along with low-temperature annealing, can reduce the root mean square roughness of the film.

[0059] Figure 15 Hysteresis loop diagrams of the flexible high-energy-storage capacitor films prepared in Examples 11-13 and Comparative Examples 1-2; from Figure 15 It can be seen that the multilayer heterostructure films annealed at 700℃ all exhibit certain relaxation-like properties, while the composite film PL annealed at 550℃ exhibits near-linear polarization behavior.

[0060] Figure 16 The breakdown field strength diagrams are for the flexible high-energy-storage capacitor films prepared in Examples 11-13 and Comparative Examples 1-2. from Figure 16 It can be seen that the PL composite film annealed at 550°C has the highest breakdown field strength. This is because low-temperature annealing retains more shallow-level defects. These defects reduce current by trapping charge carriers, thereby suppressing breakdown and resulting in a higher breakdown field strength than the PL composite film annealed at 700°C. Furthermore... Figure 17 Leakage current diagrams of the flexible high-energy-storage capacitor films prepared in Examples 11-13 and Comparative Examples 1-2; from Figure 17 It can be seen that as the applied electric field increases, the leakage current of all thin films increases; and in the composite thin films annealed at 700°C, the number of heterostructures is negatively correlated with the leakage current. This is attributed to the polarization coupling effect induced by the heterostructure, which can optimize the charge distribution inside the thin film and block the transport of charge carriers. Therefore, under the same voltage conditions, the thin film with more heterostructures has a smaller leakage current.

[0061] Figure 18 The energy storage performance diagrams are for the flexible high-energy-storage-characteristic capacitor films prepared in Examples 11-13 and Comparative Examples 1-2. from Figure 18 It is evident that among crystalline composite thin films, the PL composite film exhibits the best energy storage performance, with energy densities 3.83 times and 1.41 times that of pure PZO and PLZT films, respectively. Its energy storage efficiency is slightly lower than that of pure PZO films but higher than that of PLZT films. Therefore, introducing relaxor ferroelectric PLZT into PZO films to construct heterogeneous composite structures can enhance the film's energy storage performance through interfacial coupling effects, synergistically optimizing the breakdown field strength and polarization properties.

[0062] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A flexible high-energy-storage capacitor film and its preparation method, wherein the flexible high-energy-storage capacitor film is composed of an antiferroelectric layer material and a relaxation layer material, characterized in that, Includes the following steps: I. Preparation of lead zirconate precursor solution: Lead acetate was dissolved in ethylene glycol methyl ether and acetic acid, and the solution was heated and stirred until clear to obtain solution A. After cooling to room temperature, zirconium isopropoxide was added to solution A and stirred to obtain a lead zirconate precursor solution. II. Preparation of lead lanthanum zirconate titanate precursor solution: Acetic acid and lanthanum lead nitrate were dissolved in ethylene glycol methyl ether and acetic acid, and heated and stirred until clear to obtain solution B. After cooling to room temperature, zirconium isopropoxide and tetrabutyl titanate were added to solution B, and acetylacetone was added as a stabilizer. The mixture was stirred to obtain a lanthanum lead zirconate titanate precursor solution. III. Preparation of antiferroelectric composite thin films: Lead zirconate precursor solution and lead zirconate titanate lanthanum precursor solution were spin-coated sequentially onto a substrate. The wet film was then dried on a flat plate heater and placed in a rapid annealing furnace for heat treatment to obtain a flexible capacitor film with high energy storage characteristics.

2. The method for preparing a flexible high-energy-storage capacitor film according to claim 1, characterized in that, The antiferroelectric layer material is lead zirconate PbZrO3 (PZO), and the relaxor layer material is lead zirconate titanate Pb. 0.9 La 0.1 Zr 0.52 Ti 0.48 O3 (PLZT).

3. The method for preparing a flexible high-energy-storage capacitor film according to claim 1, characterized in that, The concentration of the lead zirconate precursor solution mentioned in step one is 0.1 mol / L to 0.45 mol / L.

4. The method for preparing a flexible high-energy-storage capacitor film according to claim 1, characterized in that: The concentration of the lead lanthanum zirconate titanate precursor solution in step two is 0.1 mol / L to 0.45 mol / L.

5. The method for preparing a flexible high-energy-storage capacitor film according to claim 1, characterized in that: The heating and stirring temperature in step two is 50℃~70℃; the substrate in step three is a flexible mica substrate.

6. The method for preparing a flexible high-energy-storage capacitor film according to claim 1, characterized in that: The sequence of spin-coating precursors on the substrate in step three is as follows: PZO (lead zirconate), PLZT (lead lanthanum zirconate titanate), PLPLP (1 layer of lead zirconate / 1 layer of lead lanthanum zirconate titanate / 2 layers of lead zirconate / 1 layer of lead lanthanum zirconate titanate / 1 layer of lead zirconate), PLP (2 layers of lead zirconate / 2 layers of lead lanthanum zirconate titanate / 2 layers of lead zirconate), PL (1 layer of lead zirconate / 1 layer of lead lanthanum zirconate titanate / 1 layer of lead zirconate / 1 layer of lead lanthanum zirconate titanate / 1 layer of lead zirconate / 1 layer of lead lanthanum zirconate titanate), LP (1 layer of lead lanthanum zirconate titanate / 1 layer of lead zirconate / 1 layer of lead lanthanum zirconate titanate / 1 layer of lead zirconate / 1 layer of lead lanthanum zirconate titanate / 1 layer of lead zirconate).

7. The method for preparing a flexible high-energy-storage capacitor film according to claim 1, characterized in that: The drying temperature described in step three is 350℃~450℃.

8. The method for preparing a flexible high-energy-storage capacitor film according to claim 1, characterized in that: The heat treatment temperature described in step three is 550~750℃.

9. The method for preparing a flexible high-energy-storage capacitor film according to claim 1, characterized in that: The protective gas for the heat treatment environment described in step three is oxygen.

10. The application of the flexible high-energy-storage capacitor film obtained by the preparation method according to any one of claims 1-9, characterized in that: A flexible, high-energy-storage-characteristic capacitor film is used in film capacitors.

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