WO2023273213A1 - Multi-component relaxor ferroelectric thin film material having superlattice structure and ultra high energy storage efficiency, and preparation method therefor - Google Patents

Abstract

Disclosed in the present application are a multi-component relaxor ferroelectric thin film material having a superlattice structure and ultra high energy storage efficiency, and a preparation method therefor. The multi-component relaxor ferroelectric thin film material comprises a substrate layer, a bottom electrode layer formed on the substrate layer, and an actual functional layer formed on the bottom electrode layer, the actual functional layer being a multi-layer structure thin film having a relaxor ferroelectric property and grown using the bottom electrode layer as a basis. The preparation method therefor comprises: selecting a rigid STO layer having a crystal orientation of [100] to serve as the substrate layer; forming an SRO layer on the STO substrate to serve as the bottom electrode layer; forming a BTO-STO-BFO multi-layer structure on the SRO layer to serve as an actual functional layer, and obtaining the multi-component relaxor ferroelectric thin film material. The multi-component relaxor ferroelectric thin film material of the present application is a superlattice structure, has advantageous properties of a high saturation polarization intensity, a low remanent polarization intensity, and a high breakdown field, and also has an excellent energy storage density and an excellent energy storage efficiency.

Description

Multicomponent relaxor ferroelectric thin film material with superlattice structure and ultrahigh energy storage efficiency and preparation method thereof technical field

The present application relates to the field of relaxor ferroelectric energy storage materials, more specifically, to a multi-component relaxor ferroelectric thin film material with a superlattice structure and ultrahigh energy storage efficiency and a preparation method thereof.

Background technique

In recent years, the development and research of energy storage equipment on dielectric energy storage materials has received more and more attention. The research content mainly focuses on three aspects: (1) the improvement of the energy storage performance of dielectric energy storage materials; (2) the dielectric energy storage materials. Construction of various new structures of energy storage materials; (3) Exploration of the internal structure or defects of dielectric energy storage materials.

The research on dielectric energy storage materials mainly focuses on two types of antiferroelectric materials and relaxor ferroelectric materials. Antiferroelectric materials have high breakdown field strength and saturation polarization, but the energy loss is too large and the energy storage density cannot be achieved. reach a higher value. Compared with antiferroelectric materials, relaxor ferroelectric materials have larger breakdown field strength and saturation polarization, and have lower remnant polarization and energy loss, so they are more suitable as capacitors to achieve larger energy storage performance.

technical problem

At present, relaxor ferroelectric materials are mostly lead-based dielectric energy storage materials. Lead-based dielectric energy storage materials are often used in capacitors due to their high energy storage density. However, lead-based dielectric energy storage materials have great harm to the environment and human body. Harm, so scientific research began to study lead-free dielectric energy storage materials. A difficult problem in the research process is that the energy storage density of lead-free dielectric energy storage materials is not as high as that of lead-based dielectric energy storage materials. Based on this, scientific research has begun to adopt a variety of different new structures to improve the energy storage performance of lead-free dielectric energy storage materials, including two-phase solid solution, interface engineering technology and other methods, among which interface engineering technology is more efficient.

At the same time, during the research process, it was also found that the internal structure or defects of the dielectric energy storage material are also crucial to the energy storage performance of the material. A capacitor with a denser internal structure and fewer defects will have higher energy storage density and energy storage efficiency. However, there are defects in the internal structure of dielectric energy storage materials, mainly manifested as oxygen vacancies, cracks, and low density.

Therefore, it is meaningful to develop a dielectric energy storage material with a denser internal structure.

technical solution

In order to improve the current problems of poor energy storage density and energy storage efficiency due to defects in the internal structure of dielectric energy storage materials, this application provides a multi-component relaxor ferroelectric with superlattice structure and ultra-high energy storage efficiency. Thin film materials and methods for their preparation.

In the first aspect, the present application provides a multi-component relaxor ferroelectric thin film material with a superlattice structure and ultra-high energy storage efficiency, and adopts the following technical scheme:

A multi-component relaxation ferroelectric thin film material with a superlattice structure and ultrahigh energy storage efficiency, comprising a base layer, a bottom electrode layer formed on the base layer, and a practical electrode layer formed on the bottom electrode layer functional layer;

The actual functional layer is a multilayer thin film with relaxor ferroelectricity grown on the basis of the bottom electrode layer.

By adopting the above technical scheme, the prepared multi-component relaxor ferroelectric thin film material has a superlattice structure, and a better quality relaxor ferroelectric thin film can be grown, and has a high saturation polarization value and low remnant polarization. value, high breakdown field strength, and has excellent energy storage density and energy storage efficiency.

Preferably, the base layer is a rigid SrTiO ₃ (STO) base, and the crystal plane orientation of the STO base is [100].

Preferably, the bottom electrode layer is a SrRuO ₃ (SRO) layer grown based on the base layer.

Preferably, the actual functional layer is a superlattice structure formed by repeated multi-period stacking of the multi-layer structure film.

Preferably, the multi-layer structure film includes a lower layer, a middle layer and an upper layer that are sequentially stacked and grown on the bottom electrode layer, the constituent elements of the lower layer include Ba and Ti, and the constituent elements of the middle layer include Sr and Ti, so The constituent elements of the upper layer include Bi and Fe.

Preferably, the multilayer structure thin film is BaTiO ₃ (BTO)-SrTiO ₃ (STO)-BiFeO ₃ (BFO) structure.

Preferably, the total thickness of the upper layer and the total thickness of the middle layer in the actual functional layer are smaller than the thickness of the bottom electrode layer, the lower layer of the multilayer structure film is the main layer of the actual functional layer, and the lower layer The total thickness accounts for 80% to 85% of the total thickness of the actual functional layer.

By adopting the above technical scheme, the energy storage density of the dielectric energy storage material is related to the thickness of the material, and the overall thickness of the material is thinner, which is conducive to improving the energy storage density. After experiments, the total thickness of the lower layer is controlled to account for 80% of the total thickness of the actual functional layer. The materials prepared between ~85% have better energy storage density and energy storage efficiency.

Preferably, the thickness of the bottom electrode layer is 10-30 nm, the total thickness of the upper layer and the middle layer in the actual functional layer are both 5-25 nm, and the total thickness of the lower layer in the actual functional layer is 180-30 nm. 220nm, the thickness of the actual functional layer is 220-260nm.

Preferably, the thickness of the bottom electrode layer is 20-25nm, the total thickness of the upper layer and the middle layer in the actual functional layer is 40-50nm, the total thickness of the lower layer in the actual functional layer is 200-220nm, the The thickness of the actual functional layer is 250~260nm.

In the second aspect, the present application provides a method for preparing a multi-component relaxor ferroelectric thin film material with a superlattice structure and ultrahigh energy storage efficiency, and adopts the following technical scheme:

A method for preparing a multi-component relaxation ferroelectric thin film material with a superlattice structure and ultrahigh energy storage efficiency, comprising the following steps:

(1) Select the base layer with a specific crystal plane orientation;

(2) Generate a bottom electrode layer on the selected base layer with a specific crystal plane orientation;

(3) A multi-layer structure film with relaxor ferroelectricity is formed on the bottom electrode layer as the actual functional layer to obtain a multi-component relaxor ferroelectric film material.

Preferably, the following steps are included:

(1) Select the rigid STO layer with crystal plane orientation [100] as the base layer;

(2) Generate an SRO layer on the STO substrate as the bottom electrode layer;

(3) A BTO-STO-BFO multilayer structure is generated on the SRO layer as the actual functional layer to obtain a multi-component relaxor ferroelectric thin film material.

Preferably, the generation of the base layer in step (2) and the generation of the actual functional layer in step (3) both adopt a pulsed laser deposition method.

Preferably, step (3) includes the following steps:

A. Place the BTO target, STO target and BFO target on three adjacent target positions respectively;

B. Bond the STO substrate in step (1) and place it in the growth chamber of the pulsed laser deposition system, directly above the main target, and control the distance between the STO substrate and the target at 55-75cm;

C. Switch the BTO target position to the main target position, and turn on the laser to bombard the BTO target for 200~300 rounds;

D. Quickly switch the STO target position to the main target position, and turn on the laser to bombard the STO target for 33~55 rounds;

E. Quickly switch the BFO target position to the main target position, and turn on the laser to bombard the BFO target for 17~25 rounds;

F. Repeat the process of cycling steps C to E for 40 to 60 times to obtain a BTO-STO-BFO multi-component relaxor ferroelectric thin film material with a repeat cycle of N being 40 to 60.

Preferably, the deposition vacuum of the bottom electrode layer in step (2) is ≤1×10 ^-7 Pa, the deposition temperature is 680~720°C, the oxygen partial pressure is 75~75mTorr, the laser energy is 340~360mJ, and the pulse laser frequency is 8~10Hz, the deposition temperature rate is 25~35°C/min, the laser focal length is -5~5mm, and the deposition rate is 2~5nm/min.

Preferably, the deposition vacuum of the actual functional layer in step (3) is ≤1×10 ^-7 Pa, the deposition temperature is 710~760°C, the oxygen partial pressure is 3~10mTorr, the laser energy is 340~360mJ, and the pulse laser frequency is 2~7Hz, the deposition temperature rate is 25~35°C/min, the laser focal length is -30~30mm, and the deposition rate is 2~5nm/min.

By controlling the deposition parameters of the bottom electrode layer and the actual functional layer, the prepared material not only has better energy storage density and energy storage efficiency, but also has better internal structure and density.

Preferably, the multi-component relaxation ferroelectric thin film material obtained is subjected to post-cooling treatment, comprising the following steps:

a. Place the prepared multi-component relaxor ferroelectric thin film material at a temperature of 710-760°C and an oxygen partial pressure of 3-10mTorr for 30-50min;

b. Keeping the oxygen partial pressure constant, slowly cool the multi-component relaxor ferroelectric thin film material to room temperature at a cooling rate of 5-10°C/min.

By controlling the cooling rate under the original deposition oxygen partial pressure atmosphere, the internal defects of the prepared material can be reduced, the density can be improved, and the performance can be improved.

Beneficial effect

In summary, the present application includes at least one of the following beneficial technical effects:

1. The multi-component relaxor ferroelectric thin film material prepared by this application has a relaxor ferroelectric thin film crystal structure. It is based on the premise that the perovskite oxide SrRuO ₃ thin film is used as the bottom electrode, and the core lower layer BaTiO ₃ , the middle layer SrTiO ₃ and The upper layer of BiFeO ₃ relaxor ferroelectric thin film is used as the dielectric layer. This multi-component material with relaxor ferroelectricity is a superlattice structure, which can grow better quality relaxor ferroelectric thin film.

2. The multi-component relaxor ferroelectric thin film material prepared by this application has the advantages of high saturation polarization value, low remanent polarization value, and high breakdown field strength, and has excellent energy storage density and energy storage efficiency; When the repetition period reaches 50, the energy storage density of the prepared multi-component relaxor ferroelectric thin film can reach 50.35J/cm ³ , and the energy storage efficiency can be kept above 88%, which is conducive to the improvement of the energy storage performance of the energy storage device .

3. The multi-component relaxor ferroelectric thin film material prepared by this application can maintain good and stable energy storage performance in the working environment of 0~120°C or frequency of 50K~1MHz, which is conducive to its high temperature or other conditions. Practical applications in the field of energy storage devices.

Description of drawings

Fig. 1 is the schematic diagram of the preparation of the multi-component relaxor ferroelectric thin film material in the embodiment of the present application;

Fig. 2 is the XRD pattern of the relaxation ferroelectric thin film material prepared by the embodiment 2 of the present application and the comparative example;

Fig. 3 is the TEM picture of the relaxor ferroelectric thin film material prepared in Example 2 of the present application;

Fig. 4 is the P-V diagram of the relaxation ferroelectric thin film material prepared by the embodiment 2 and the comparative example of the present application;

Figure 5 is a C-V diagram of the relaxor ferroelectric thin film material prepared in Example 2 of the present application;

Fig. 6 is the J-V diagram of the relaxation ferroelectric thin film material prepared by Example 2 and Comparative Example of the present application;

Figure 7 is a diagram of the recoverable energy storage density (W _rec ) of the relaxor ferroelectric thin film materials prepared in Example 2 and Comparative Example of the present application;

Fig. 8 is a diagram of the energy storage efficiency (η) of the relaxor ferroelectric thin film materials prepared in Example 2 and Comparative Example of the present application.

Embodiments of the present invention

In recent years, the development and research of energy storage devices on dielectric energy storage materials has received great attention, among which relaxor ferroelectric materials have large breakdown field strength and saturation polarization, while having lower remnant polarization Strength and energy loss, so it is more suitable as a capacitor to achieve greater energy storage performance. But at this stage, relaxor ferroelectric materials are mostly lead-based dielectric energy storage materials, but lead-based dielectric energy storage materials are extremely harmful to the environment and human body, and the energy storage density of lead-free dielectric energy storage materials is lower than that of lead-based dielectric materials. Energy storage materials have high energy storage density. During the research process, the applicant found that the internal structure or defect of the dielectric energy storage material is also crucial to the energy storage performance of the material. A capacitor with a denser internal structure and fewer defects will have higher energy storage density and energy storage efficiency. However, there are defects in the internal structure of dielectric energy storage materials, mainly manifested as oxygen vacancies, cracks, and low density. After a lot of research, this application has developed a material with a denser internal structure and relaxation ferroelectricity, which is a superlattice structure with high saturation polarization values, low remanent polarization values, and high breakdown field At the same time, it has excellent energy storage density and energy storage efficiency.

In order to facilitate understanding of the technical solution of the present application, the present application will be described in further detail below in conjunction with the accompanying drawings and embodiments, but it is not regarded as the protection scope limited by the present application.

Example

Example 1

A multi-component relaxor ferroelectric thin film material with a superlattice structure and ultrahigh energy storage efficiency, comprising: a base layer, a bottom electrode layer formed on the base layer, and an actual functional layer formed on the bottom electrode layer, The actual functional layer is a superlattice structure formed by repeated multi-period superimposition of a multi-layer structure film with relaxor ferroelectricity grown on the bottom electrode layer. In this embodiment, the repetition period N=40.

As shown in Figure 1, the preparation method of the above-mentioned multi-component relaxor ferroelectric thin film material comprises the following steps:

(1) Select the base layer, the base layer is a rigid SrTiO ₃ (STO) substrate, and the crystal plane orientation of the STO substrate is [100].

(2) Using a pulsed laser deposition system, deposit and form a SrRuO ₃ (SRO) layer on the STO base layer as the bottom electrode layer. The thickness of the deposited bottom electrode layer is 22nm; during the deposition process, the vacuum degree of the deposition chamber is controlled to be ≤1×10 ^{- 7} Pa, the deposition temperature is 690°C, the oxygen partial pressure is 80mTorr, the laser energy is 360mJ, the pulse laser frequency is 10Hz, the deposition temperature rate is 35°C/min, the laser focal length is -5mm, and the deposition rate is 5nm/min.

(3) Using a pulsed laser deposition system, a BaTiO ₃ (BTO)-SrTiO ₃ (STO)-BiFeO ₃ (BFO) thin film with a multi-layer structure with diffusive ferroelectricity is deposited on the SRO bottom electrode layer as the actual functional layer , the actual thickness of the functional layer formed by deposition is 252nm, in which the thickness of the BTO layer is controlled at 210nm, and the total thickness of the STO layer and the BFO layer is controlled at 42nm. The specific steps are as follows:

A. Place the BTO target, STO target and BFO target on three adjacent target positions respectively;

B. Bond the STO substrate in step (1) and place it directly above the main target in the growth chamber of the pulsed laser deposition system, control the distance between the STO substrate and the target to 60cm, and adjust the vacuum of the deposition chamber ≤1×10 ^-7 Pa, the deposition temperature is 730°C, the oxygen partial pressure is 5mTorr, the laser energy is 360mJ, the pulse laser frequency is 5Hz, the deposition temperature rate is 25°C/min, the laser focal length is -20mm, and the deposition rate is 5nm /min;

The specific steps of bonding treatment are as follows:

B1. Clean the surface of the STO substrate, use a dust-free cotton swab dipped in a small amount of alcohol solution to wipe the surface of the STO substrate, and repeat 3 times until there are no other impurities on the surface of the STO substrate;

B2. Coat the surface of the heating backplane with a conductive silver paste solution, and bond the cleaned STO substrate to the heating backplane;

B3. Place the STO substrate together with the heated backplate in the growth chamber of the pulsed laser deposition system;

C. Switch the BTO target position to the main target position, and turn on the laser to bombard the BTO target with a fixed number of 300 rounds;

D. Quickly switch the STO target position to the main target position, and turn on the laser to bombard the STO target with a fixed number of 50 rounds;

E. Quickly switch the BFO target position to the main target position, and turn on the laser to bombard the BFO target with a fixed number of 25 rounds;

F. Repeat the process of cycling steps C to E for 40 times to obtain a BTO-STO-BFO multi-component relaxor ferroelectric thin film material with a repetition period of N=40.

(4) cooling and post-processing the prepared multi-component relaxor ferroelectric thin film material, including the following steps:

a. Place the prepared multi-component relaxor ferroelectric thin film material for 50 minutes at a temperature of 730° C. and an oxygen partial pressure of 5 mTorr;

b. Keeping the oxygen partial pressure constant, slowly cool the multi-component relaxor ferroelectric thin film material to room temperature at a cooling rate of 10°C/min to obtain a finished BTO-STO-BFO multi-component relaxor ferroelectric thin film material.

Example 2

The difference from Example 1 is that the fixed number of rounds for bombarding the BTO target in step C is 240 rounds, the fixed number of rounds for bombarding the STO target in step D is 40 rounds, and the fixed number of rounds for bombarding the BFO target in step E is 20 rounds. The process of cycling steps C to E was repeated 50 times to obtain a BTO-STO-BFO multi-component relaxor ferroelectric thin film material with a repetition period of N=50.

Example 3

The difference from Example 1 is that the fixed number of rounds for bombarding the BTO target in step C is 200 rounds, the fixed number of rounds for bombarding the STO target in step D is 33 rounds, and the fixed number of rounds for bombarding the BFO target in step E is 17 rounds. The process of cycling steps C to E was repeated 60 times to obtain a BTO-STO-BFO multi-component relaxor ferroelectric thin film material with a repetition period of N=60.

comparative example

The difference from Example 1 is that in step (3), a BTO thin film with ferroelectricity is deposited and formed on the SRO bottom electrode layer directly as the actual functional layer, with a thickness of 252 nm.

As shown in Figure 2, it can be clearly seen from the XRD pattern that in addition to the STO substrate peaks (100), (200) and (300), there are BTO phases that grow preferentially along (100), (200) and (300), The SRO phase of the bottom electrode layer grows preferentially along (100), (200) and (300), which proves the formation of single crystal of BTO-STO-BFO film.

As shown in Figure 3, it can be obtained from the high-resolution TEM image of Figure 3a that the thickness of the actual functional layer and the thickness of the bottom electrode layer are 252nm and 22nm, respectively, and it can be seen from the low-resolution TEM image of Figure 3b that as the main The BTO layer of the first layer grows alternately with the STO layer and BFO layer as the secondary layer, and there is a very obvious boundary, which proves that the BTO-STO-BFO multi-component relaxor ferroelectric thin film is layered.

As shown in Figure 4, compared with the pure BTO film, the BTO-STO-BFO multi-component relaxor ferroelectric film not only greatly improves the saturation polarization value and breakdown field strength, but also increases the breakdown field strength from 45V to 80V. , but also reduces the value of remanent polarization, and at the same time makes the P-V ring more slender, greatly improving the energy storage performance.

As shown in Figure 5, the C-V diagram of the BTO-STO-BFO multi-component relaxed ferroelectric film, the capacitance value of the frequency from 50KHz to 1MHz, the curves under different C-V are more stable, which proves that the BTO-STO-BFO multi-component relaxation Ferroelectric thin films have better frequency dependence.

As shown in Figure 6, the leakage current density of the BTO-STO-BFO multi-component relaxor ferroelectric film is much smaller than that of the pure BTO ferroelectric film, making the BTO-STO-BFO multi-component relaxor ferroelectric film The breakdown field strength is greatly improved, which greatly improves the energy storage performance.

As shown in Figure 7, the energy storage density of the BTO-STO-BFO multi-component relaxor ferroelectric film can reach 50.35J/cm ³ , which is higher than the energy storage density of pure BTO ferroelectric film of 19.89J/cm ³ . up 153%.

As shown in Figure 8, the energy storage efficiency of the BTO-STO-BFO multi-component relaxor ferroelectric film can reach 92.49%, and has been at an ultra-high energy storage efficiency of more than 88%. Compared with the pure BTO ferroelectric film The energy storage efficiency is 53.46%, an increase of 73%.

This specific embodiment is only an explanation of this application, and it is not a limitation of this application. Those skilled in the art can make modifications to this embodiment without creative contribution according to needs after reading this specification, but as long as the rights of this application All claims are protected by patent law.

Claims (16)

A multi-component relaxor ferroelectric thin film material with a superlattice structure and ultrahigh energy storage efficiency, characterized in that it includes: a base layer, a bottom electrode layer formed on the base layer, and a bottom electrode layer formed on the bottom The actual functional layer on the electrode layer; The actual functional layer is a multilayer thin film with relaxor ferroelectricity grown on the basis of the bottom electrode layer. The multi-component relaxor ferroelectric thin film material with superlattice structure and ultra-high energy storage efficiency according to claim 1, characterized in that: the base layer is a rigid SrTiO ₃ (STO) base, and the STO base The crystal plane orientation is [100]. The multi-component relaxor ferroelectric thin film material with superlattice structure and ultrahigh energy storage efficiency according to claim 1, characterized in that: the bottom electrode layer is SrRuO ₃ (SRO )Floor. The multi-component relaxor ferroelectric thin film material with superlattice structure and ultra-high energy storage efficiency according to claim 1, characterized in that: the actual functional layer is formed by repeated multi-period superimposition of the multi-layer structure thin film superlattice structure. The multi-component relaxor ferroelectric thin film material with superlattice structure and ultrahigh energy storage efficiency according to any one of claims 1-4, characterized in that: the multi-layer structure thin film includes successively stacked and grown on For the lower layer, middle layer and upper layer on the bottom electrode layer, the constituent elements of the lower layer include Ba and Ti, the constituent elements of the middle layer include Sr and Ti, and the constituent elements of the upper layer include Bi and Fe. The multi-component relaxor ferroelectric film material with superlattice structure and ultra-high energy storage efficiency according to claim 5, characterized in that: the multi-layer structure film is BaTiO ₃ (BTO)-SrTiO ₃ (STO )-BiFeO ₃ (BFO) structure. The multi-component relaxor ferroelectric film material with superlattice structure and ultra-high energy storage efficiency according to claim 6, characterized in that: the total thickness of the upper layer and the total thickness of the middle layer in the actual functional layer are both Less than the thickness of the bottom electrode layer, the lower layer of the multilayer structure film is the main layer of the actual functional layer, and the total thickness of the lower layer accounts for 80% to 85% of the total thickness of the actual functional layer. The multi-component relaxor ferroelectric thin film material with superlattice structure and ultra-high energy storage efficiency according to claim 7, characterized in that: the thickness of the bottom electrode layer is 10-30nm, and the actual functional layer The total thickness of the upper layer and the total thickness of the middle layer are both 5-25nm, the total thickness of the lower layer in the actual functional layer is 180-220nm, and the thickness of the actual functional layer is 220-260nm. The multi-component relaxor ferroelectric thin film material with superlattice structure and ultra-high energy storage efficiency according to claim 8, characterized in that: the thickness of the bottom electrode layer is 20-25nm, and the actual functional layer The total thickness of the upper layer and the middle layer is 40-50nm, the total thickness of the lower layer in the actual functional layer is 200-220nm, and the thickness of the actual functional layer is 250-260nm. The preparation method of the multi-component relaxation ferroelectric thin film material with superlattice structure and ultrahigh energy storage efficiency described in any one of claims 1-9, is characterized in that, comprises the following steps: (1) Select the base layer with a specific crystal plane orientation; (2) Generate a bottom electrode layer on the selected base layer with a specific crystal plane orientation; (3) A multi-layer structure film with relaxor ferroelectricity is formed on the bottom electrode layer as the actual functional layer to obtain a multi-component relaxor ferroelectric film material. The preparation method of a multi-component relaxor ferroelectric thin film material having a superlattice structure and ultrahigh energy storage efficiency according to claim 10, characterized in that it comprises the following steps: (1) Select the rigid STO layer with crystal plane orientation [100] as the base layer; (2) Generate an SRO layer on the STO substrate as the bottom electrode layer; (3) A BTO-STO-BFO multilayer structure is generated on the SRO layer as the actual functional layer to obtain a multi-component relaxor ferroelectric thin film material. The method for preparing a multi-component relaxor ferroelectric thin film material with a superlattice structure and ultra-high energy storage efficiency according to claim 11, characterized in that: the base layer is formed in step (2) and the base layer is formed in step (3). Generating the actual functional layer adopts the pulsed laser deposition method. The method for preparing a multi-component relaxor ferroelectric thin film material with superlattice structure and ultrahigh energy storage efficiency according to claim 12, characterized in that step (3) includes the following steps: A. Place the BTO target, STO target and BFO target on three adjacent target positions respectively; B. Bond the STO substrate in step (1) and place it directly above the main target in the growth chamber of the pulsed laser deposition system. The distance between the STO substrate and the target is controlled at 55-75cm; C. Switch the BTO target position to the main target position, and turn on the laser to bombard the BTO target for 200~300 rounds; D. Quickly switch the STO target position to the main target position, and turn on the laser to bombard the STO target for 33~55 rounds; E. Quickly switch the BFO target position to the main target position, and turn on the laser to bombard the BFO target for 17~25 rounds; F. Repeat the process of cycling steps C to E for 40 to 60 times to obtain a BTO-STO-BFO multi-component relaxor ferroelectric thin film material with a repeat cycle of N being 40 to 60. The method for preparing a multi-component relaxor ferroelectric thin film material with a superlattice structure and ultra-high energy storage efficiency according to claim 12, characterized in that: the vacuum degree of deposition of the bottom electrode layer in step (2) is ≤1 ×10 ^-7 Pa, deposition temperature is 680~720℃, oxygen partial pressure is 75~75mTorr, laser energy is 340~360mJ, pulse laser frequency is 8~10Hz, deposition temperature rate is 25~35℃/min, laser focal length -5~5mm, deposition rate 2~5nm/min. The method for preparing a multi-component relaxor ferroelectric thin film material with a superlattice structure and ultrahigh energy storage efficiency according to claim 13, characterized in that the vacuum degree of deposition of the actual functional layer in step (3) is ≤1 ×10 ^-7 Pa, deposition temperature is 710~760℃, oxygen partial pressure is 3~10mTorr, laser energy is 340~360mJ, pulse laser frequency is 2~7Hz, deposition temperature rate is 25~35℃/min, laser focal length -30~30mm, deposition rate 2~5nm/min. The method for preparing a multi-component relaxor ferroelectric thin film material with superlattice structure and ultra-high energy storage efficiency according to claim 13, characterized in that: the prepared multi-component relaxor ferroelectric thin film material is After cooling, the processing includes the following steps: a. Place the prepared multi-component relaxor ferroelectric thin film material at a temperature of 710-760°C and an oxygen partial pressure of 3-10mTorr for 30-50min; b. Keeping the oxygen partial pressure constant, slowly cool the multi-component relaxor ferroelectric thin film material to room temperature at a cooling rate of 5-10°C/min.