Inverse perovskite electrolyte thin film, all-solid-state thin film sodium battery and preparation method

Abstract

A perovskite - type inverse electrolyte thin film, all - solid - state thin - film sodium battery and preparation method thereof belong to the field of energy storage technology. By using magnetron co - sputtering to bombard NaB target and Na2AO4 target, a Na3AO4B electrolyte thin film with a perovskite - type inverse structure having good crystallinity and easy - to - control film layers is synthesized in situ. An all - solid - state thin - film sodium battery is constructed by using the above - mentioned Na3AO4B electrolyte thin film with a perovskite - type inverse structure. The electrolyte thin film has good ionic conductivity, appropriate film thickness, and good crystallinity to improve the battery performance of the all - solid - state thin - film sodium battery. The all - solid - state thin - film sodium battery prepared by successive layer - by - layer deposition realizes the solid - solid contact of each film layer while reducing the operation complexity, further improving the battery performance of the all - solid - state thin - film sodium battery.

Description

Technical Field

[0001] This application relates to the technical field of energy storage, and more particularly, to an anti-perovskite electrolyte film, an all-solid-state thin-film sodium battery, and a preparation method thereof. Background Art

[0002] All-solid-state sodium-ion batteries have the potential advantages of low cost and high safety, and are one of the hot-developing technologies in the field of energy storage. The all-solid-state thin-film sodium battery belongs to a type of all-solid-state sodium-ion battery, and each part thereof is obtained through thin-film technology and stacked in the order of a general battery structure. Therefore, it has the characteristics of being ultra-thin, integratable, and having a relatively high energy density, and can be designed into different shapes and sizes according to application requirements, and is often applied to fields such as micro-nano devices, portable electronic products, mobile medical devices, national defense and military industries, and large-scale energy storage.

[0003] In recent years, certain research has been carried out on thin-film sodium batteries at home and abroad. However, some key technologies have not been effectively broken through, and there are still common drawbacks such as complex preparation processes, poor electrical conductivity, and unstable discharge. Summary of the Invention

[0004] Based on the above deficiencies, this application provides an anti-perovskite electrolyte film, an all-solid-state thin-film sodium battery, and a preparation method thereof to partially or completely improve, or even solve, the problems of complex preparation and poor electrical properties of all-solid-state thin-film sodium batteries in related technologies.

[0005] The above technical problems of this application are achieved through the following technical solutions:

[0006] In a first aspect, an example of this application provides a preparation method of an anti-perovskite electrolyte film. The chemical composition of the anti-perovskite electrolyte film is Na3AO4B, where A is selected from one of sulfur element and selenium element, and B is selected from one of chlorine element and fluorine element;

[0007] The preparation method includes:

[0008] In a first vacuum environment where both a NaB target and a Na2AO4 target exist, an anti-perovskite electrolyte film is deposited by magnetron co-sputtering.

[0009] In the above implementation process, for the first time, by means of magnetron co-sputtering, an anti-perovskite type Na3AO4B electrolyte is directly synthesized in-situ using a NaB target and a Na2AO4 target, so as to obtain a Na3AO4B electrolyte thin film with good crystallinity and easy-to-control film thickness. Compared with the existing process of synthesizing Na3AO4B powder by solid-phase reaction and then pressing it into a solid electrolyte thin film, when using the preparation method of the anti-perovskite electrolyte thin film provided in this example to prepare the Na3AO4B electrolyte thin film, there is no need to add a conductive agent and a binder in the traditional film-forming process, and an electrolyte thin film with a micro-nano thickness can be obtained. The preparation method of the anti-perovskite electrolyte thin film provided in this example is simple to operate, the NaB target and the Na2AO4 target are easy to obtain, the preparation process of the thin film takes a short time, and it is conducive to industrial production.

[0010] Combined with the first aspect, in the first possible implementation manner of the first aspect of the present application, the vacuum degree of the first vacuum environment is 2×10 -4 Pa to 5×10 -6 Pa, and the vacuum degree is achieved by pumping vacuum with a two-stage vacuum pump of a mechanical pump and a molecular pump;

[0011] When performing magnetron co-sputtering, 2 sccm to 10 sccm of argon gas and 2 sccm to 10 sccm of oxygen gas are introduced into the first vacuum environment, and the gas flow ratio of argon gas to oxygen gas is maintained at 1 to 5:1.

[0012] In the above implementation process, when the vacuum degree reaches 2×10 -4 Pa to 5×10 -6 Pa, 2 sccm to 10 sccm of argon gas and 2 sccm to 10 sccm of oxygen gas are introduced at a gas flow ratio maintained at 1 to 5:1, which can maintain a good gas environment required for magnetron sputtering, generate sufficient argon ions to bombard the target. A suitable higher vacuum degree can improve the sputtering rate, thereby improving the purity and interface bonding ability of each film layer (due to less residual gas in the vacuum chamber. Residual gases such as water vapor, carbon dioxide gas, etc.), and can enable the generated argon ions to bombard the target at a sufficient speed (to avoid collision with gas ions or molecules, resulting in the inability of argon ions to be accelerated and thus unable to bombard the target), and then a film layer with uniform distribution and high density can be prepared.

[0013] In the second aspect, the example of the present application provides an anti-perovskite electrolyte thin film, which is prepared by the preparation method of the anti-perovskite electrolyte thin film provided in the first aspect.

[0014] In the above implementation process, a solid anti-perovskite electrolyte film is prepared by the method for preparing an anti-perovskite electrolyte film provided in the first aspect. The film has good crystallinity, an appropriate thickness, and does not require the addition of conductive agents and binders in traditional film-forming processes. The thickness of the electrolyte film can reach the micro-nano level.

[0015] In a third aspect, an example of the present application provides an all-solid-state thin-film sodium battery, including a substrate, a first metal film, a first electrode film, the anti-perovskite electrolyte film provided in the second aspect, a second electrode film, a second metal film, and an oxide film that are sequentially stacked.

[0016] In the above implementation process, compared with traditional energy storage batteries, such as all-solid-state lithium batteries, the present application provides an all-solid-state thin-film sodium battery. Sodium is abundant, the battery cost is low, and it has high safety. The all-solid-state thin-film sodium battery provided by the present application includes an anti-perovskite electrolyte film. Compared with traditional liquid electrolytes or solid electrolytes obtained by tabletting, the (Na3SO4F) solid electrolyte film material with an anti-perovskite structure synthesized by magnetron co-sputtering in-situ reaction has characteristics such as high crystallinity, appropriate film thickness, good insensitivity to the water-oxygen environment, high ionic conductivity, and a wide electrochemical window, which can improve the conductive performance and charge-discharge stability of the all-solid-state thin-film sodium battery.

[0017] Moreover, the all-solid-state thin-film sodium battery provided by the present application has characteristics such as ultra-thin, integrable, light weight, and high specific capacity, and can meet the development needs of microelectronic devices such as dynamic random access memories, microsensors, and microelectromechanical systems, portable electronic products, mobile medical devices, national defense and military industries, and large-scale energy storage.

[0018] Combined with the third aspect, in the first possible implementation manner of the third aspect of the present application, the first metal film is selected from one of a silver film, a gold film, a copper film, or a titanium film;

[0019] And / or, the second metal film is selected from one of a silver film, a gold film, a copper film, or a titanium film.

[0020] Combined with the third aspect, in the second possible implementation manner of the third aspect of the present application, the oxide film is selected from one of an aluminum oxide film, a zinc oxide film, or a titanium oxide film.

[0021] Combined with the third aspect, in the third possible implementation manner of the third aspect of the present application, the substrate is selected from any one of a silicon wafer, a silicon dioxide wafer, a quartz glass wafer, a sapphire wafer, an aluminum sheet, a copper sheet, and a stainless steel sheet.

[0022] In the above implementation process, one of silver thin film, gold thin film, copper thin film or titanium thin film is provided at the first electrode thin film and the second electrode thin film, so as to facilitate the collection of the current generated by the battery cell (positive electrode - electrolyte - negative electrode), and then facilitate the external large - current output. Silver thin film, gold thin film, copper thin film or titanium thin film has characteristics such as high conductivity and light weight, which can reduce the weight of the battery, improve the stability of the battery and the current transmission performance.

[0023] Moreover, one of alumina thin film, zinc oxide thin film or titanium oxide thin film is provided outside the second metal thin film, which can protect the second metal thin film and improve the stability of the battery.

[0024] Using a silicon wafer, a silicon dioxide wafer, a quartz glass wafer, a sapphire wafer, an aluminum sheet, a copper sheet or a stainless steel sheet, etc. as the substrate, the substrate has high flatness and strong bonding ability with the metal thin film, so as to support and improve the characteristics of the metal thin film, and then improve the structural stability of the all - solid - state thin - film sodium battery.

[0025] In a fourth aspect, an example of the present application provides a preparation method of an all - solid - state thin - film sodium battery, including:

[0026] In a first vacuum environment where both NaB target and Na2AO4 target exist, a perovskite - type anti - electrolyte thin film is deposited on the first electrode thin film by magnetron co - sputtering.

[0027] Among them, the chemical composition of the perovskite - type anti - electrolyte thin film is Na3AO4B, A is selected from one of sulfur element and selenium element, and B is selected from one of chlorine element and fluorine element.

[0028] In the above implementation process, the present application provides a preparation method of an all - solid - state thin - film sodium battery. For the first time, by using magnetron co - sputtering, a perovskite - type anti - electrolyte thin film with the chemical composition of Na3AO4B is synthesized in situ through the NaB target and the Na2AO4 target, so as to obtain a solid perovskite - type anti - electrolyte thin film with good crystallinity and controllable film thickness. By using magnetron co - sputtering to synthesize the perovskite - type Na3AO4B electrolyte thin film in situ, the NaB target and the Na2AO4 target have low costs and are easy to obtain. There is no need to synthesize the perovskite - structure Na3AO4B material or target through a complex preparation process in advance. The preparation process is simple, which is beneficial to reducing production costs, improving production efficiency and facilitating industrial production.

[0029] Combined with the fourth aspect, in the first possible implementation manner of the fourth aspect of the present application, the preparation method further includes a layer - by - layer continuous deposition operation:

[0030] In a first vacuum environment where a first metal target, a first electrode target, a NaB target, a Na2AO4 target, a second electrode target, a second metal target, and an oxide target are simultaneously present, sequentially depositing a first metal film, a first electrode film, an antiperovskite electrolyte film, a second electrode film, a second metal film, and an oxide film in a stacked arrangement on a substrate by magnetron sputtering;

[0031] Among them, the first metal film and the second metal film are deposited by DC magnetron sputtering, the first electrode film, the second electrode film and the oxide film are deposited by RF magnetron sputtering, and the antiperovskite electrolyte film is deposited by RF magnetron co-sputtering.

[0032] In the above implementation process, the first metal film, the first electrode film, the antiperovskite electrolyte film, the second electrode film and the oxide film are deposited on the substrate in a stacked manner in sequence by the magnetron sputtering coating technology with in-situ controllable characteristics (that is, after the deposition of each layer of film on the substrate is completed, the substrate with the film deposited is not taken out from the vacuum chamber of the multi-target magnetron sputtering coating system, and the next film layer is directly deposited on the film formed after the previous deposition operation), which can avoid the influence of changes in the gas environment (such as water vapor, carbon dioxide, etc. in the atmospheric environment) on the interface contact of each film layer, especially the interface contact problem between the antiperovskite electrolyte film and the electrode film, and reduce the interface resistance. In addition, through the continuous deposition operation layer by layer, the solid-solid contact of different film layers can be achieved (there is no water vapor, etc. at the contact interface of different film layers), which can enhance the adhesion of each film layer. Since true solid-solid contact can be achieved between the antiperovskite electrolyte film and the electrode film in the layer-by-layer continuous deposition coating method provided in the present application, no further heat treatment process is required to improve the electrode / electrolyte interface quality, thereby avoiding problems such as large interface impedance, poor interface compatibility, and interface separation during charging and discharging caused by high-temperature thermal expansion mismatch.

[0033] Moreover, through the in-situ controllable magnetron sputtering coating technology, the thickness ratio of each film layer can be easily adjusted to meet the battery size requirements of different devices, and can further improve the stability and charge and discharge performance of the prepared all-solid-state thin-film sodium battery.

[0034] In addition, according to the properties of the target, different magnetron sputtering technologies are used to sputter-deposit corresponding film layers with uniform and good controllability on targets with different properties (such as according to the characteristics of metal targets or non-metal targets, etc.). In the first vacuum environment, by controlling the corresponding DC or RF operation switch, while depositing a film layer with uniform distribution and good compactness, the operation process of film formation using different magnetron sputtering coating systems can be simplified, and the operation convenience can be improved. By using the RF magnetron co-sputtering method to bombard the NaB target and the Na2AO4 target to in-situ react and synthesize the perovskite-type Na3AO4B electrolyte thin film, there is no need to synthesize the perovskite structure Na3AO4B target through a complex preparation process in advance. The preparation process is simple, which is beneficial to reducing production costs, improving production efficiency, and facilitating industrial production.

[0035] In a fifth aspect, an example of the present application provides a all-solid-state thin-film sodium battery, which is prepared according to the preparation method of the all-solid-state thin-film sodium battery provided in the fourth aspect.

[0036] In the above implementation process, the all-solid-state thin-film sodium battery prepared by the preparation method provided in the first implementation manner of the fourth aspect of the present application has good bonding between each film layer, has a film layer thickness with an appropriate ratio, can reduce the interfacial impedance, improve the ion transport at the interface, and improve the stability of the all-solid-state thin-film sodium battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for description in the embodiments or the prior art.

[0038] Figure 1 It is the GIXRD diagram of the perovskite electrolyte thin film provided by the example of the present application;

[0039] Figure 2 It is the surface morphology diagram of the perovskite electrolyte thin film provided by the example of the present application;

[0040] Figure 3 It is the cross-sectional morphology diagram of the perovskite electrolyte thin film provided by the example of the present application;

[0041] Figure 4 It is the surface scanning element distribution diagram of the perovskite electrolyte thin film provided by the example of the present application;

[0042] Figure 5 It is the EDX energy spectrum diagram of the perovskite electrolyte thin film provided by the example of the present application;

[0043] Figure 6 It is the EIS curve diagram of the perovskite electrolyte thin film provided by the example of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0044] The embodiments of the present application will be described in detail below in conjunction with examples. However, those skilled in the art will understand that the following examples are only used to illustrate the present application and should not be construed as limiting the scope of the present application. For those not specified in the examples, the operations are carried out under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments not specified by the manufacturer can all be obtained as conventional products through commercial purchase.

[0045] The following specifically describes the anti-perovskite electrolyte film, all-solid-state thin-film sodium battery and preparation method according to the embodiments of the present application:

[0046] All-solid-state sodium-ion batteries have the potential advantages of low cost and high safety, and are one of the hot development technologies in the energy storage field. All-solid-state thin-film sodium batteries belong to a type of all-solid-state sodium-ion batteries, with characteristics such as ultra-thin, integrable, and relatively high energy density, and can be designed with different shapes and sizes according to application requirements, and are often applied in fields such as micro-nano devices, portable electronic products, mobile medical devices, national defense and military industries, and large-scale energy storage.

[0047] In recent years, certain research has been carried out on thin-film sodium-ion batteries at home and abroad. However, some key technologies have not been effectively broken through, and there are still common disadvantages such as complex preparation processes, poor electrical conductivity, and unstable discharge. The inventor believes that the fundamental reason for the poor electrical performance and unstable discharge of all-solid-state sodium-ion batteries is the solid electrolyte.

[0048] The inventor believes that high-performance solid electrolytes are the key factors for realizing all-solid-state sodium-ion batteries. In order to improve the battery performance of all-solid-state sodium-ion batteries, the inventor attempts to prepare electrolyte films using NASICON-type ceramics and sulfides.

[0049] However, the inventor finds that NASICON-type ceramics and sulfides have high preparation costs, high flammability, poor machinability, and narrow intrinsic voltage windows, and cannot further improve the battery performance of all-solid-state sodium-ion batteries. The inventor believes that the Na3SO4F (NSOF) material with an anti-perovskite structure has good insensitivity to the water-oxygen environment, relatively high ionic conductivity, and a wide electrochemical window, and is expected to further improve the battery performance of all-solid-state sodium-ion batteries. However, current work on NSOF has all focused on theoretical calculations and improving ionic conductivity, and no one has yet paid attention to the novel synthesis method of this material and its application research in all-solid-state thin-film sodium-ion batteries.

[0050] Therefore, the inventors attempted to synthesize NSOF powder using the traditional solid-state reaction method and then press it into a solid electrolyte film layer. However, the inventors found that it was impossible to form a thin film material with a micro-nano thickness using the pressing method, and the NSOF thin film obtained by pressing could not achieve true solid-solid contact with the electrode. To improve the interface quality between the electrode and the electrolyte, the inventors attempted to perform a heat treatment process on the battery structure constructed by the NSOF thin film obtained by pressing and the electrode. The inventors found that during the heat treatment process, due to the high-temperature thermal expansion mismatch, problems such as an increase in interface impedance, poor interface compatibility, and separation at the interface during the charge and discharge process of the battery would occur.

[0051] To further obtain the NSOF thin film, the inventors attempted to prepare the NSOF thin film by traditional film-making methods. The inventors found that when preparing the NSOF thin film by traditional film-making methods, it was necessary to add a conductive agent and a binder, and there was a possibility of leakage of the conductive agent and the binder. Moreover, the synthesis of NSOF materials by the solid-state reaction method has a complex preparation process, consumes time, requires a high temperature, and is not conducive to the industrial production of thin-film sodium-ion batteries.

[0052] Based on this, the inventors provided a method for preparing an anti-perovskite electrolyte thin film. In a first vacuum environment where both a NaB target and a Na2AO4 target are present, an anti-perovskite electrolyte thin film is deposited and formed by magnetron co-sputtering for the first time. The chemical composition of the anti-perovskite electrolyte thin film is Na3AO4B, where A is selected from one of sulfur and selenium, and B is selected from one of chlorine and fluorine.

[0053] In the example, the NaB target and the Na2AO4 target are respectively screwed into the target holders in the vacuum chamber of the multi-target magnetron sputtering device, the thin film substrate is fixed at the sample holder in the vacuum chamber, and the vacuum chamber is evacuated by two-stage vacuum pumps, namely a mechanical pump and a molecular pump. When the vacuum degree of the vacuum chamber is 2×10 -4 Pa to 5×10 -6 Pa, 2 sccm to 10 sccm of argon gas and 2 sccm to 10 sccm of oxygen gas are introduced into the vacuum chamber, and the gas flow ratio of argon gas to oxygen gas is maintained at 1 to 5:1. The angles of the two targets and the target-substrate distance are adjusted, the sample holder rotation switch is turned on, the magnetron sputtering switch is turned on, the deposition parameters (such as sputtering power and sputtering time, etc.) are adjusted, and both the NaB target and the Na2AO4 target are bombarded to in-situ react and form an anti-perovskite electrolyte thin film on the thin film substrate rotating at a certain speed.

[0054] Through the above method, a Na3AO4B electrolyte thin film with an inverse perovskite structure can be in-situ formed from a NaB target and a Na2AO4 target. The NaB target and the Na2AO4 target are low-cost and easy to obtain. By magnetron co-sputtering the NaB target and the Na2AO4 target for in-situ reaction, while obtaining Na3AO4B with a well-crystallized inverse perovskite structure, it is also convenient to control the thickness of the film layer, realizing the preparation of a micro-nano scale Na3AO4B electrolyte thin film.

[0055] This application does not limit the specific model of the multi-target magnetron sputtering coating device, and relevant personnel can make corresponding selections according to needs. For example, the Arrayed Materials CPS102, JGP560C15 type multi-target magnetron sputtering coating device.

[0056] This application does not limit how to adjust each sputtering parameter. Relevant personnel can make corresponding adjustments on the premise of ensuring the in-situ formation of the Na3AO4B electrolyte thin film by magnetron co-sputtering the NaB target and the Na2AO4 target.

[0057] In some possible implementation manners, in order to adapt to a copper backplane with a size of Φ50.8×2 mm, the target size can be set to Φ50.8×3 mm. The rotation speed of the sample holder can be adjusted to 30 - 60 r / min, the sputtering power can be set to 40 - 70 W, and the sputtering time can be set to 2 - 8 h.

[0058] Furthermore, the inventor provides an inverse perovskite electrolyte thin film, which is obtained by the preparation method of the inverse perovskite electrolyte thin film.

[0059] This application does not limit the substrate material on which the inverse perovskite electrolyte thin film is deposited. Relevant personnel can deposit the inverse perovskite electrolyte thin film provided in this application on the corresponding film layer or thin film substrate according to needs. In one possible implementation manner, the inverse perovskite electrolyte thin film provided in this application also includes substrates such as silicon wafers and glass slides.

[0060] Furthermore, the inventor provides a all-solid-state thin-film sodium battery, including a substrate, a first metal thin film, a first electrode thin film, the inverse perovskite electrolyte thin film provided in the second aspect, a second electrode thin film, a second metal thin film, and an oxide thin film, which are stacked in sequence.

[0061] This application does not limit the specific materials of the substrate, the first metal thin film, the first electrode thin film, the second electrode thin film, the second metal thin film, and the oxide thin film. Relevant personnel can make corresponding selections according to needs.

[0062] In some possible implementation manners, the substrate is selected from any one of silicon wafers, silicon dioxide wafers, quartz glass wafers, sapphire wafers, aluminum sheets, copper sheets, and stainless steel sheets.

[0063] Optionally, the first metal thin film and the second metal thin film are each selected from one of conductive metals such as silver thin film, gold thin film, copper thin film, titanium thin film, etc., or conductive semiconductor materials such as carbon and composite materials. The first metal thin film and the second metal thin film can be of the same material.

[0064] Optionally, the oxide thin film is selected from one of aluminum oxide thin film, zinc oxide thin film or titanium oxide thin film.

[0065] Optionally, the first electrode thin film can be selected from sodium-based transition metal oxides such as NaCoO2, NaMnO2, sodium phosphates, sodium fluorophosphates or sodium pyrophosphates.

[0066] Optionally, the second electrode thin film can be selected from materials such as hard carbon, Prussian blue, Cu2Sb and its homologous substitutes.

[0067] This application does not limit the thickness of each film layer, and relevant personnel can make corresponding settings according to needs. In some possible embodiments, the thickness of the first metal thin film and the second metal thin film can be set to 100 - 300 nm, the thickness of the inverse perovskite electrolyte thin film can be set to 300 - 1000 nm, and the thickness of the oxide thin film can be set to 50 - 100 nm.

[0068] Furthermore, the inventor provides a method for preparing an all-solid-state thin-film sodium battery. In a first vacuum environment where both NaB target and Na2AO4 target are present, an inverse perovskite electrolyte thin film is deposited on the first electrode thin film by magnetron co-sputtering;

[0069] Among them, the chemical composition of the inverse perovskite electrolyte thin film is Na3AO4B, A is selected from one of sulfur element and selenium element, and B is selected from one of chlorine element and fluorine element.

[0070] This application does not limit the preparation methods of other film layers in the all-solid-state thin-film sodium battery except the inverse perovskite electrolyte thin film, and relevant personnel can make corresponding selections according to needs.

[0071] In a possible embodiment, the method for preparing the all-solid-state thin-film sodium battery provided by this application further includes a layer-by-layer continuous deposition operation:

[0072] Spin the first metal target, the first electrode target, the NaB target, the Na2AO4 target, the second electrode target, the second metal target and the oxide target into the target holders in the vacuum chamber of the multi-target magnetron sputtering coating device, and fix the substrate at the sample holder in this vacuum chamber. Evacuate the vacuum chamber with a two-stage vacuum pump consisting of a mechanical pump and a molecular pump. When the vacuum degree of the vacuum chamber is 2×10 -4 Pa - 5×10-6 When the pressure is Pa, introduce 2 sccm to 10 sccm of argon gas and 2 sccm to 10 sccm of oxygen gas into the vacuum chamber, and keep the gas flow ratio of argon gas to oxygen gas at 1 to 5:1. Adjust the angles of each target and the target-substrate distance, and turn on the sample holder rotation switch. Then perform the following operations in sequence:

[0073] Control the DC magnetron sputtering switch, adjust the magnetron sputtering parameters, bombard the first metal target, and form a first metal thin film on the substrate; control the RF magnetron sputtering switch, adjust the magnetron sputtering parameters, bombard the first electrode target, and form a first electrode thin film on the first metal thin film; control the RF magnetron sputtering switch, adjust the magnetron sputtering parameters, and bombard the NaB target and the Na2AO4 target simultaneously to form an inverse perovskite electrolyte thin film by in-situ reaction on the first electrode thin film; control the RF magnetron sputtering switch, adjust the magnetron sputtering parameters, bombard the second electrode target, and form a second electrode thin film on the inverse perovskite electrolyte thin film; control the DC magnetron sputtering switch, adjust the magnetron sputtering parameters, bombard the second metal target, and form a second metal thin film on the second electrode thin film; control the RF magnetron sputtering switch, adjust the magnetron sputtering parameters, bombard the oxide target, and form an oxide thin film on the second metal thin film.

[0074] In a possible implementation manner, the layer-by-layer continuous deposition operation may not be adopted. For example, the first step: in the first single-target magnetron sputtering device, deposit and form a first metal thin film on the substrate by magnetron sputtering. After the deposition of the first metal thin film is completed, take out the substrate deposited with the first metal thin film from the first vacuum chamber of the first single-target magnetron sputtering device.

[0075] The second step: put the substrate deposited with the first metal thin film into the second single-target magnetron sputtering device, and deposit and form a first electrode thin film on the first metal thin film by magnetron sputtering. After the deposition of the first electrode thin film is completed, take out the sample deposited with the first electrode thin film from the second vacuum chamber of the second single-target magnetron sputtering device.

[0076] The third step: put the sample of the second step into the multi-target magnetron sputtering device, and deposit and form an inverse perovskite electrolyte thin film on the first electrode thin film by co-sputtering. After the deposition of the inverse perovskite electrolyte thin film is completed, take out the sample deposited with the inverse perovskite electrolyte thin film from the vacuum chamber of the multi-target magnetron sputtering device.

[0077] According to the above steps, prepare the second electrode thin film, the second metal thin film, and the oxide thin film in sequence.

[0078] Alternatively, in a possible implementation, the first metal thin film, the first electrode thin film, the second electrode thin film, the second metal thin film, and the oxide thin film can be prepared by conventional thin film preparation methods. For example, the tablet pressing method, the spin coating method, the screen printing method, the dip coating method, the inkjet printing method, and the spray pyrolysis method, etc.

[0079] Furthermore, the inventor provides a all-solid-state thin film sodium battery, and each film layer in the all-solid-state thin film sodium battery is prepared by successive layer-by-layer deposition operations.

[0080] The following further describes in detail the preparation method of the inverse perovskite electrolyte thin film and the preparation method of the all-solid-state thin film sodium battery of the present application in conjunction with embodiments.

[0081] Example 1

[0082] This Example 1 provides an inverse perovskite electrolyte thin film, and its preparation method includes the following steps:

[0083] Step 1. Pretreatment of the substrate: The substrate is ultrasonically cleaned; the cleaning steps are: ultrasonically cleaning the substrate with anhydrous ethanol for 10 min, then ultrasonically cleaning it in acetone for 15 min, and finally cleaning it with deionized water several times and then placing it in a vacuum drying oven for drying and standby;

[0084] In this example, the substrate is a circular silicon wafer, and the size of the substrate is 2 inches.

[0085] Step 2. Preparation of the target: The targets used for the inverse perovskite electrolyte thin film are sodium fluoride (NaF) target and sodium sulfate (Na2SO4) target, which are respectively made by hot pressing and sintering of NaF powder and Na2SO4 powder. The size of the target used is Φ50.8×3 mm (to fit the copper backplane with a size of Φ50.8×2 mm).

[0086] Step 3. Magnetron co-sputtering in-situ reaction to synthesize the inverse perovskite electrolyte thin film:

[0087] (a) Fix the cleaned and dried silicon wafer substrate on the sample holder, screw the fixed sample holder into the substrate buckle on the ultra-high vacuum multi-target magnetron sputtering coating system (Arrayed Materials CPS102), and at the same time screw the NaF target and the Na2SO4 target into the target buckle.

[0088] (b) Use a two-stage vacuum pump of a mechanical pump and a molecular pump to pump the vacuum. When the chamber vacuum degree of the ultra-high vacuum multi-target magnetron sputtering coating system reaches 2×10 -4After Pa, 5 sccm of argon and 5 sccm of oxygen are introduced into the cavity, and the gas flow ratio of argon to oxygen is maintained at 1:1. Adjust the angles of the NaF target and the Na2SO4 target and the target-substrate distance to appropriate positions. Turn on the substrate rotation switch and adjust the substrate rotation speed to 50 r / min.

[0089] (c) On the fixed silicon wafer substrate, an anti-perovskite structured Na3SO4F electrolyte thin film is synthesized in-situ by radio frequency magnetron co-sputtering. The thickness of the thin film is 100 nm; the sputtering power is 60 W, the sputtering time is 4 h, and the deposition is carried out at room temperature.

[0090] After the preparation is completed, turn off the radio frequency power supply and the rotation switch, take out the sample, and place the taken-out sample in a dry airtight container for structural morphology characterization and electrochemical performance testing (if there is no test item, the sample can not be taken out).

[0091] Example 2

[0092] This Example 2 provides an anti-perovskite electrolyte thin film, which is different from Example 1 in that: a layer of metallic silver thin film is deposited on each side of the anti-perovskite electrolyte thin film obtained in Example 2, that is, Example 2 provides a symmetric sandwich-structured metallic silver thin film - anti-perovskite electrolyte thin film - metallic silver thin film. The preparation method is as follows:

[0093] On the basis of step 2 of Example 1, a metallic silver target is also provided; on the basis of step 3 of Example 1, it also includes the deposition of a metallic silver thin film, that is, a layer of metallic silver thin film is deposited before and after the deposition of the Na3SO4F electrolyte thin film (the film thickness in Example 2 is 1.5 μm).

[0094] Among them, the deposition operation of the metallic silver thin film includes: using direct current magnetron sputtering, a layer of metallic silver thin film with a thickness of 100 nm is in-situ grown on both sides of the Na3SO4F electrolyte thin film; the sputtering power is 30 W, the sputtering time is 1 h, and the deposition is carried out at room temperature.

[0095] Example 3

[0096] This Example 3 provides a all-solid-state thin film sodium battery, and its preparation method includes the following steps:

[0097] Step 1. Pretreatment of the substrate: The substrate is ultrasonically cleaned; the cleaning steps are: ultrasonically clean the substrate with absolute ethanol for 20 min, then ultrasonically clean it in acetone for 30 min, and finally clean it with deionized water several times and place it in a vacuum drying oven for drying and standby;

[0098] In this example, the substrate is a circular silicon wafer, and the size of the substrate is 2 inches.

[0099] Step 2. Preparation of target materials: The target material for the first metal thin film is pure titanium, the target material for the first electrode thin film is NaCoO2, the target material for the second electrode thin film is hard carbon, the target material for the second metal thin film is pure silver, and the target material for the oxide thin film is Al2O3. The target materials for the inverse perovskite electrolyte thin film are sodium fluoride (NaF) target material and sodium sulfate (Na2SO4) target material.

[0100] The size of the above-mentioned target materials is Φ50.8×3 mm (the size of the used copper backplane is Φ50.8×2 mm).

[0101] Step 3. Deposition of all-solid-state thin-film sodium battery layer by layer continuously:

[0102] (a) Fix the cleaned and dried silicon wafer substrate on the sample holder, screw the fixed sample holder into the substrate holder of the ultra-high vacuum multi-target magnetron sputtering coating system (Arrayed Materials CPS102), and at the same time screw the pure titanium target material, NaCoO2 target material, NaF target material, Na2SO4 target material, hard carbon target material, pure silver target material, and Al2O3 target material into the target holders.

[0103] (b) Use a mechanical pump and a molecular pump as two-stage vacuum pumps to evacuate. When the chamber vacuum of the ultra-high vacuum multi-target magnetron sputtering coating system reaches 5×10 -6 Pa, introduce 10 sccm of argon gas and 10 sccm of oxygen gas into the chamber, and keep the gas flow ratio of argon gas to oxygen gas at 1:1. Adjust the angles of each target material and the target-substrate distance to appropriate positions (the angles of each target material and the target-substrate distance can be readjusted when sputtering different target materials). Turn on the sample holder rotation switch and adjust the substrate rotation speed to 30 r / min.

[0104] (c) On the fixed silicon wafer substrate, grow a 100-nm-thick metallic titanium thin film by DC magnetron sputtering; the sputtering power is 30 W, the sputtering time is 1 h, and the deposition is carried out at room temperature.

[0105] (d) After the deposition of the metallic titanium thin film is completed, use RF magnetron sputtering to in-situ deposit a 200-nm-thick NaCoO2 positive electrode thin film on the metallic titanium thin film; the sputtering power is 50 W, the sputtering time is 2 h, and the deposition is carried out at room temperature.

[0106] (e) After the deposition of the NaCoO2 positive electrode thin film is completed, use RF co-sputtering to in-situ react and synthesize an inverse perovskite-structured Na3SO4F electrolyte thin film with a thickness of 100 nm; the sputtering power is 60 W, the sputtering time is 4 h, and the deposition is carried out at room temperature.

[0107] (f) After the deposition of the Na3SO4F electrolyte thin film with an anti-perovskite structure is completed, a hard carbon thin film with a thickness of 60 nm is in-situ deposited on the Na3SO4F electrolyte thin film with an anti-perovskite structure by radio frequency magnetron sputtering; the sputtering power is 50 W, the sputtering time is 2 h, and the deposition is carried out at room temperature.

[0108] (g) After the deposition of the hard carbon thin film is completed, a metal silver thin film with a thickness of 100 nm is in-situ grown on the hard carbon thin film by direct current magnetron sputtering; the sputtering power is 30 W, the sputtering time is 1 h, and the deposition is carried out at room temperature.

[0109] (h) After the deposition of the metal silver thin film is completed, an Al2O3 thin film with a thickness of 100 nm is in-situ grown on the metal silver thin film by radio frequency magnetron sputtering; the sputtering power is 30 W, the sputtering time is 1 h, and the deposition is carried out at room temperature.

[0110] After the preparation is completed, turn off the radio frequency power supply, the direct current power supply and the rotation switch, and take out the sample.

[0111] Experimental example

[0112] (1) The anti-perovskite electrolyte thin film obtained in Example 1 was subjected to GIXRD testing, and the test results are as Figure 1 shown.

[0113] (2) The morphology of the anti-perovskite electrolyte thin film obtained in Example 1 was observed, and the results are as Figure 2 and Figure 3 shown. Among them, Figure 2 is the surface morphology diagram of the anti-perovskite electrolyte thin film prepared in Example 1, Figure 3 is the cross-sectional morphology diagram of the anti-perovskite electrolyte thin film prepared in Example 1.

[0114] (3) The surface scanning elemental analysis and energy spectrum analysis were carried out on the anti-perovskite electrolyte thin film obtained in Example 1, and the results are as Figure 4 and Figure 5 shown.

[0115] Result analysis: It can be seen from Figure 2 and Figure 3 that the anti-perovskite electrolyte thin film obtained in Example 1 has a uniform and flat film layer. Combining Figure 1 , Figure 4 and Figure 5 it can be seen that the elements in the anti-perovskite electrolyte thin film obtained in Example 1 are evenly distributed, and the electrolyte thin film is Na3SO4F.

[0116] (4) Perform EIS analysis on the inverse perovskite electrolyte film obtained in Example 2. An AC impedance test is carried out using a blocking electrode structure, and the test equipment is the Solartron Analytical 1400 CellTest System of AMETEK, USA; the test conditions are 10Mv, 100KHz to 0.01Hz. The results are as Figure 6 shown.

[0117] Result analysis: As can be seen from Figure 6 , the AC impedance of the inverse perovskite electrolyte film prepared by magnetron co-sputtering in-situ reaction is about 53.5Ω. According to the film thickness (about 1.5μm) and the effective area of the sandwich structure (1.887cm 2 ), the room temperature ionic conductivity of the Na3SO4F film can be calculated by the ionic conductivity formula to be about 1.5×10 -6 S / cm, which is two orders of magnitude higher than the room temperature ionic conductivity of the Na3SO4F powder reported in the prior art (~10 -8 S / cm), significantly indicating the advantages of the present invention.

[0118] The above are only the preferred embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing an anti-perovskite electrolyte thin film, characterized in that, The chemical composition of the inverse perovskite electrolyte film is Na3AO4B, where A is selected from one of sulfur and selenium, and B is selected from one of chlorine and fluorine; The preparation method includes: In a first vacuum environment with both a NaB target and a Na2AO4 target, the inverse perovskite electrolyte film with a thickness of 300 - 1000 nm is deposited by magnetron co-sputtering; The vacuum degree of the first vacuum environment is 2×10 -4 Pa to 5×10 -6 Pa, and the vacuum degree is achieved by evacuating with a two-stage vacuum pump consisting of a mechanical pump and a molecular pump; When performing the magnetron co-sputtering, 2 sccm - 10 sccm of argon and 2 sccm - 10 sccm of oxygen are introduced into the first vacuum environment, and the gas flow ratio of the argon to the oxygen is maintained at 1 - 5:1; the sputtering power is 40 - 70 W.

2. An anti-perovskite electrolyte thin film, characterized in that, It is obtained by the preparation method of the inverse perovskite electrolyte film described in claim 1.

3. A all-solid-state thin-film sodium battery, characterized in that, It includes a substrate, a first metal film, a first electrode film, the inverse perovskite electrolyte film provided by claim 2, a second electrode film, a second metal film, and an oxide film, which are stacked in sequence.

4. The all-solid-state thin-film sodium battery according to claim 3, characterized in that, The first metal film is selected from one of a silver film, a gold film, a copper film, or a titanium film; And / or, the second metal film is selected from one of a silver film, a gold film, a copper film, or a titanium film.

5. The all-solid-state thin-film sodium battery according to claim 3 or 4, characterized in that, The oxide film is selected from one of an aluminum oxide film, a zinc oxide film, or a titanium oxide film.

6. The all-solid-state thin-film sodium battery according to claim 3, characterized in that, The substrate is selected from any one of a silicon wafer, a silicon dioxide wafer, a quartz glass wafer, a sapphire wafer, an aluminum sheet, a copper sheet, and a stainless steel sheet.

7. A method for preparing an all-solid-state thin-film sodium battery, characterized in that, The preparation method includes: In a first vacuum environment with both a NaB target and a Na2AO4 target, an inverse perovskite electrolyte film with a thickness of 300 - 1000 nm is deposited on the first electrode film by magnetron co-sputtering; Among them, the chemical composition of the inverse perovskite electrolyte film is Na3AO4B, A is selected from one of sulfur and selenium, and B is selected from one of chlorine and fluorine; the vacuum degree of the first vacuum environment is 2×10 -4 Pa to 5×10 -6 Pa, and the vacuum degree is achieved by pumping vacuum with a two-stage vacuum pump of a mechanical pump and a molecular pump; When performing the magnetron co-sputtering, 2 sccm - 10 sccm of argon and 2 sccm - 10 sccm of oxygen are introduced into the first vacuum environment, and the gas flow ratio of the argon to the oxygen is maintained at 1 - 5:1; the sputtering power is 40 - 70 W.

8. The method for preparing an all-solid-state thin-film sodium battery according to claim 7, characterized in that, The preparation method further includes a layer-by-layer continuous deposition operation: In the first vacuum environment with a first metal target, a first electrode target, the NaB target, the Na2AO4 target, a second electrode target, a second metal target, and an oxide target, a first metal film, the first electrode film, the inverse perovskite electrolyte film, a second electrode film, a second metal film, and an oxide film are sequentially deposited on the substrate by magnetron sputtering to form a stacked structure; Among them, the first metal film and the second metal film are deposited by DC magnetron sputtering, the first electrode film, the second electrode film, and the oxide film are deposited by RF magnetron sputtering, and the inverse perovskite electrolyte film is deposited by RF magnetron co-sputtering.

9. A all-solid-state thin-film sodium battery, characterized in that, It is obtained by the preparation method of the all-solid-state thin-film sodium battery described in claim 8.

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