CN113336547A - Oxide type solid electrolyte film and preparation method thereof - Google Patents

Abstract

The invention provides an oxide type solid electrolyte film and a preparation method thereof, firstly, lithium salt, lanthanum salt, zirconium salt, aluminum salt, calcium salt, citric acid, glycol, binder and surfactant are taken to be mixed with deionized water, stirred and heated to prepare 0.11-0.13mol/L precursor solution; adding the precursor solution into an injector of an ultrasonic spraying instrument, placing the cut silicon substrate on a sample platform of the ultrasonic spraying instrument, spraying the silicon substrate at the flow rate of 0.008-0.011ml/min, opening the sample platform, heating to 110-; and sintering the sprayed silicon substrate, raising the temperature to 1095-1105 ℃ at the heating rate of 2.8-3.2 ℃/min, preserving the heat, and naturally cooling to room temperature to obtain the solid electrolyte film. The method can prepare the high-ionic conductivity solid electrolyte film with excellent electrochemical performance in a short time and a simple process, has low cost and can be industrially produced.

Description

Oxide type solid electrolyte film and preparation method thereof

Technical Field

The invention relates to the technical field of lithium ion battery materials, in particular to an oxide type solid electrolyte film and a preparation method thereof.

Background

In the current research of battery field, lithium ion batteries have the advantages of small volume, light weight, high energy density, wide electrochemical window, environmental friendliness and the like, and are widely applied, but the electrolyte inside the traditional liquid lithium ion battery is flammable and explosive, so that the safety problem is widely concerned. In contrast, solid electrolytes are stable in properties and can perfectly solve such safety problems, and are mainly classified into oxide types and sulfide types, and the oxide types include garnet, perovskite, NASICON, LISICON, and other structural types. Among them, garnet-type solid electrolyte Li₇La₃Zr₂O₁₂(LLZO) has good prospect in the application of lithium ion batteries, and has the advantages of good thermal stability, wide electrochemical window, high safety and the like.

Problem 1: a lithium lanthanum zirconium oxygen garnet-type solid electrolyte having two phases: the phase of the lithium lanthanum zirconium oxygen garnet type solid electrolyte at room temperature is mainly a tetragonal phase, lithium sites in the tetragonal phase are completely occupied by lithium, the geometric space for moving lithium ions is small, and lithium ion transmission is very difficult, so that the lithium lanthanum zirconium oxygen garnet type solid electrolyte at room temperature has very poor electric conductivity and low ionic conductivity. These problems severely restrict the application of LLZO.

If the solid electrolyte is prepared into a thin film type material, the diffusion time of lithium ions and the total impedance of the all-solid-state battery are greatly reduced, and the defect of LLZO in the aspect of ionic conductivity can be compensated. It has been reported that among the LLZO thin films, these LLZO electrolyte thin films have not been able to be applied to all-solid-state batteries due to problems of the preparation method, the substrate requirements, and the like.

Problem 2: in the existing film preparation method, the pulse laser deposition method can control the oriented growth of the LLZO film, but the deposition area is small, and the large-scale manufacture is limited; the deposition rate of the magnetron sputtering method is slow, and the prepared electrolyte film has low conductivity; and both methods need to be carried out based on a vacuum environment and the conditions are severe. The metal organic vapor deposition has remarkable advantages in the aspects of deposition speed and appearance control; atomic layer deposition, a common method for interface modification, can uniformly deposit a solid electrolyte layer on the surface of various complex substrates. It can be seen that researchers have been able to prepare LLZO ultra-thin electrolyte thin films by various methods and to precisely control the thickness of the thin films. However, due to the above-mentioned preparation method, such LLZO thin film electrolytes have not been effectively applied to all solid state batteries due to its limitations, such as severe preparation conditions, high requirements for substrate materials, low ionic conductivity of amorphous thin films, high preparation cost, etc.

Therefore, there is a great need in the art for a new solid electrolyte preparation method.

Disclosure of Invention

In view of this, the present invention provides an oxide type solid electrolyte thin film and a method for preparing the same, which can prepare a high ionic conductivity solid electrolyte thin film having excellent electrochemical properties in a short time and in a simple process, can be applied to all-solid-state batteries, and is low in cost and suitable for industrial production.

The technical scheme of the invention is realized as follows: a method for preparing an oxide type solid electrolyte film, comprising the steps of: (1) preparation of a water-based precursor solution:

according to corresponding stoichiometric ratio, mixing lithium salt, lanthanum salt, zirconium salt, aluminum salt, calcium salt, citric acid, glycol, binder and surfactant with deionized water, stirring and heating to prepare 0.11-0.13mol/L precursor solution, wherein the chemical general formula of the precursor is Li_6.55+xAl_0.15La_3-xCa_xZr₂₍OH)₂₄X is 0 to 0.15; the molar ratio of the lithium salt to the citric acid to the ethylene glycol is 1: 0.09-0.11: 0.9-1.1; wherein the Li content is excessive by 10 percent based on the stoichiometric ratio, and lithium is volatile in the high-temperature sintering process, so as to compensate the lithium loss in the high-temperature sintering process, the lithium-rich lithium battery is calledThe lithium salt is required to be in excess of 10% based on the stoichiometric ratio.

(2) Adding the precursor solution prepared in the step (1) into an injector of an ultrasonic spraying instrument, placing the cut silicon substrate on a sample platform of the ultrasonic spraying instrument, and spraying the silicon substrate at the flow rate of 0.008-0.011ml/min, wherein the solution is locally gathered on the surface of the silicon substrate due to overlarge flow rate, and the solution is not beneficial to forming a thin film;

opening the sample table and heating to 110-130 ℃, wherein the spraying cycle time is three times, each time comprises spraying one layer horizontally and spraying one layer longitudinally, six layers are sprayed for three times, and when the cycle time is 1-2 times (2-4 layers), the cycle time is too small, and the solution cannot be completely attached to the surface of the silicon substrate; when the circulation frequency is 4 times (8 layers), the solution can be gathered on the surface of the silicon substrate and cannot be uniformly distributed;

after each layer is sprayed, the mixture is placed on a magnetic stirrer to be heated at 445 ℃ and 455 ℃ for treatment;

(3) sintering the silicon substrate sprayed in the step (2), heating to 1095-1105 ℃ at a heating rate of 2.8-3.2 ℃/min, and preserving heat, wherein the silicon substrate is deformed to be not beneficial to forming a film on the surface of the solution due to overhigh sintering temperature or overlong sintering time, the conductivity of the film is reduced, and the reaction is incomplete due to overlow sintering temperature or overlong sintering time, so that a required pure sample phase cannot be completely formed, various impurity phases are generated, and the performance of the sample is not beneficial; then naturally cooling to room temperature to prepare Li_{6.55+ x}Al_0.15La_3-xCa_xZr₂O₁₂A solid electrolyte membrane.

The invention also provides Li prepared by replacing aluminum salt with equal molar quantity of gallium salt_6.55+xGa_0.15La_3-xCa_xZr₂O₁₂A solid electrolyte film; or replacing the aluminum salt with an equimolar amount of iron salt to produce Li_6.55+xFe_0.15La_3-xCa_xZr₂O₁₂A solid electrolyte membrane.

Further, in the step (1), the lithium salt is lithium nitrate, the lanthanum salt is lanthanum nitrate hexahydrate, the zirconium salt is zirconyl nitrate, the aluminum salt is aluminum nitrate nonahydrate, and the calcium salt is tetrahydrateCalcium nitrate or anhydrous calcium nitrate; the binder is a binding agent SPEEK-PSI-Li; the surfactant is a surfactant

F127。

Further, in the step (1), the binder and the surfactant are 9.8% -10.2% of the total mass of the precursor solution.

Further, in the step (1), the temperature of the stirring and heating is 85-95 ℃, preferably 90 ℃.

Further, in the step (2), the stirring heating mode is water bath heating or oil bath heating.

Further, in the step (2), the time for heating 445-455 ℃ treatment on the magnetic stirrer is 5-6 min.

And (3) further, in the step (2), the volume of the precursor solution added into a syringe of an ultrasonic spraying instrument is 9-10 ml.

Further, in the step (3), the heat preservation time is 1-3h, and preferably 1 h.

A method of forming an oxide-type solid electrolyte membrane, comprising the steps of: (1) preparation of a water-based precursor solution:

taking lithium nitrate, lanthanum nitrate hexahydrate, zirconyl nitrate, aluminum nitrate nonahydrate, calcium nitrate tetrahydrate, citric acid, glycol, a binding agent SPEEK-PSI-Li and a surfactant

F127, mixing with deionized water, stirring and heating to prepare 0.12mol/L precursor solution, wherein the chemical general formula of the precursor is Li_6.55+xAl_0.15La_3-xCa_xZr₂₍OH)₂₄X is 0 to 0.15; the molar ratio of the lithium salt to the citric acid to the ethylene glycol is 1: 0.1: 1;

(2) adding the precursor solution prepared in the step (1) into an injector of an ultrasonic spraying instrument, placing the cut silicon substrate on a sample platform of the ultrasonic spraying instrument, spraying the silicon substrate at the flow rate of 0.01ml/min, opening the sample platform, heating to 120 ℃, spraying for three times, wherein each time comprises transverse spraying one layer and longitudinal spraying one layer, spraying for six layers for three times, and placing the silicon substrate on a magnetic stirrer after each spraying for heating at 450 ℃ for 5 min;

(3) sintering the silicon substrate sprayed in the step (2), heating to 1100 ℃ at the heating rate of 3 ℃/min, preserving heat for 1h, and naturally cooling to room temperature to obtain the target product Li_6.55+xAl_0.15La_3-xCa_xZr₂O₁₂。

An oxide type solid electrolyte thin film produced by the method for producing an oxide type solid electrolyte thin film according to any one of the present invention.

Compared with the prior art, the invention has the beneficial effects that:

(1) the invention firstly prepares water-based precursor solution, sprays the solution on a silicon substrate by ultrasonic spraying, finally obtains a solid electrolyte film by adopting high-temperature heat treatment, can prepare the electrolyte film with high ionic conductivity in short time and simple process, and has the chemical general formula of Li_6.55+xAl_0.15La_3-xCa_xZr₂O₁₂、Li_6.55+xGa_0.15La_{3- x}Ca_xZr₂O₁₂、Li_6.55+xFe_0.15La_3-xCa_xZr₂O₁₂。

(2) The invention prepares the solid electrolyte into a film type material, greatly reduces the diffusion time of lithium ions and the total impedance of the all-solid-state battery, and makes up the defect of LLZO in the aspect of ionic conductivity. The main phase of the solid electrolyte prepared by the invention at room temperature is a cubic phase, lithium sites in the cubic phase are not completely occupied by lithium, and a large number of lithium vacancies exist in the whole structure, so that a channel is provided for the transmission of lithium ions, the conductivity of the solid electrolyte is greatly improved, the solid electrolyte has high conductivity at room temperature, and the ion conductivity is high.

(3) Compared with the existing thin film electrolyte preparation methods (magnetron sputtering, pulsed laser deposition and the like), the LLZO electrolyte thin film has not been effectively applied to all-solid-state batteries due to the limitations of the methods, such as harsh preparation conditions, high-requirement substrate materials, lower ion conductivity of amorphous thin films, high preparation cost and the like. The invention adopts the ultrasonic spraying method, so that the prepared solid electrolyte has excellent electrochemical performance, and the preparation process is simple, the synthesis conditions are flexible and feasible, the chemical components are easy to control, the cost is low, and the method is suitable for industrial production. Therefore, the solid electrolyte film prepared by the invention can be applied to all-solid batteries.

Drawings

FIG. 1 shows an oxide type solid electrolyte thin film Li in example 1_6.6Al_0.15La_2.95Ca_0.05Zr₂O₁₂The preparation process is shown in the figure.

FIG. 2 example 1 oxide type solid electrolyte thin film Li_6.6Al_0.15La_2.95Ca_0.05Zr₂O₁₂XRD pattern of (a). From fig. 2 it can be seen that the individual peaks at different sintering times correspond approximately to the cubic phase diagram spectrum. Only a (400) peak exists in each group of samples between 27 and 30 degrees, and no (004) peak exists, so that the main crystal phases of the obtained samples are all in a cubic phase structure.

FIG. 3 example 1 oxide type solid electrolyte thin film Li_6.6Al_0.15La_2.95Ca_0.05Zr₂O₁₂SEM image of (d). As shown in fig. 3, from left to right are electron micrographs of the sample taken at 1000 and 2000 times, respectively. Grain size non-uniformity can be seen. There are some voids and gaps, resulting in a decrease in density.

FIG. 4 shows an oxide type solid electrolyte thin film Li of example 1_6.6Al_0.15La_2.95Ca_0.05Zr₂O₁₂EIS spectra at different temperatures; the ionic conductivity is calculated to be inversely proportional to the sintering time and is 2.28 multiplied by 10 at room temperature^-5S/cm。

FIG. 5 shows an oxide type solid electrolyte thin film Li of example 5_6.6Ga_0.15La_2.95Ca_0.05Zr₂O₁₂EIS spectra at different test temperatures; by calculating the ionic conductivity at room temperatureUp to 2.28X 10^-5S/cm。

FIG. 6 shows an oxide type solid electrolyte thin film Li of example 6_6.6Fe_0.15La_2.95Ca_0.05Zr₂O₁₂EIS spectra at different test temperatures; the ionic conductivity can reach 1.14 multiplied by 10 at room temperature by calculation^-6S/cm。

Detailed Description

In order to better understand the technical content of the invention, specific examples are provided below to further illustrate the invention.

The experimental methods used in the examples of the present invention are all conventional methods unless otherwise specified.

The materials, reagents and the like used in the examples of the present invention can be obtained commercially without specific description.

Firstly, preparation of products

Example 1 preparation of oxide type solid electrolyte film

(1) Preparation of a water-based precursor solution: mixing raw materials: lithium nitrate (LiNO) in the corresponding stoichiometric ratio₃) Lanthanum nitrate hexahydrate (La (NO)₃)_{3`</sub>6H<sub>2</sub>O), zirconyl nitrate (ZrO (NO)<sub>3</sub>)<sub>2</sub>) Aluminum nitrate nonahydrate (Al (NO)<sub>3</sub>)<sub>3`}9H₂O), calcium nitrate tetrahydrate (Ca (NO)₃)_2`4H₂O), citric acid, ethylene glycol, a binding agent SPEEK-PSI-Li, a surfactant

F127 was weighed accordingly, with a stoichiometric ratio of Li to La to Zr to Al to Ca of 6.6: 2.95: 2: 0.15: 0.05 (132: 59: 40: 3: 1) in which the Li content was 10% in excess based on the stoichiometric ratio, and since lithium was volatile during high-temperature sintering, lithium nitrate (LiNO) was weighed in order to compensate for the loss of lithium during high-temperature sintering₃) The amount of the catalyst is 10% in excess. Wherein the molar ratio of lithium nitrate to citric acid to ethylene glycol is 1: 0.1: 1, the addition amount of the binder and the surfactant is 10 percent of the total mass of the precursor solution. Mixing the raw materials with appropriate amount of deionized water, and adding into the mixtureStarting a magnetic stirrer in a beaker, heating and stirring in a water bath at 90 ℃ until the raw materials are completely mixed and dissolved, observing the change of the solution amount in the stirring process, adding deionized water to maintain the concentration of the solution unchanged, and preparing 0.12mol/L precursor solution, wherein the solution is transparent, and the chemical general formula of the precursor is Li_6.6Al_0.15La_2.95Ca_0.05Zr₂₍OH)₂₄。

(2) Adding about 10ml of the precursor solution prepared in the step (1) into an injector of an ultrasonic spraying instrument, cleaning a pipeline by using the precursor solution, placing the cut silicon substrate on a heatable sample table, setting a program for spraying, and spraying the silicon substrate at a flow rate of 0.01 ml/min; the sample stage is opened and heated to 110-130 ℃, the temperature in the embodiment is heated to 120 ℃, the spraying cycle times are three times, each time comprises transverse spraying of one layer and longitudinal spraying of one layer, and six layers are sprayed in total for three times. After each layer is sprayed, the mixture is put on a magnetic stirrer to be heated to 450 ℃ for 5 min. Repeating the steps until the spraying of all the layers is finished;

(3) taking out the silicon substrate sprayed in the step (2) by using a flat forceps, putting the silicon substrate into a muffle furnace for sintering, heating to 1100 ℃ at a heating rate of 3 ℃/min, preserving heat for 1-3h, preserving heat for 1h in the embodiment, and naturally cooling to room temperature to obtain a target product Li_6.6Al_0.15La_2.95Ca_0.05Zr₂O₁₂Solid electrolyte thin film samples. The sample was taken out using flat forceps and stored in a sealed condition.

Secondly, product performance test

1. Test method

(1) XRD test

And (3) acquiring a corresponding characteristic peak by XRD test, comparing the characteristic peak with a standard cubic phase and a tetragonal phase peak in a database, judging whether a product phase required by people is generated or not, and observing the appearance of an impurity peak. The invention adopts a D2-PHASER model instrument, a Cu target ray source scans in a range of 10-80 degrees under 40Kv voltage.

(2) Scanning Electron Microscope (SEM) and energy spectrum testing

The invention adopts a Phenom Prox model scanning electron microscope to carry out microscopic morphology analysis on the doped solid electrolyte sample, and observes the crystallization condition of the sample, whether the crystal grains are uniform, the density and the like. And (4) performing a spectrum test to obtain the distribution of each element in the sample.

(3) Alternating current impedance (EIS) testing

The invention adopts a 1470E type electrochemical workstation, the vibration amplitude is 10Mv, and the frequency range is 1MHz to 0.1 Hz. The test alternating current impedance is an intuitive characterization mode for the conductivity of the solid electrolyte sample, and the alternating current impedance of the lithium ion conductor consists of a grain boundary, grain impedance and corresponding capacitance. The conductivity calculation formula is as follows:

σ＝L/(πr²)R

the symbols in the formula: sigma is the conductivity; r is the radius of the ceramic sample; r is total resistance; and L is the thickness of the ceramic sample.

The sample is measured with more than four impedance values in the range of 25-150 degrees, and after the ion conductivity is obtained according to the formula, the activation energy can be calculated by an Arrhenius formula:

lnσ＝lnσ₀-Ea/RT

the symbols in the formula: ea: activation energy; r: a molar gas constant; t: thermodynamic temperature (K).

2. Test results

FIG. 2 shows an oxide type solid electrolyte thin film Li in example 1_6.6Al_0.15La_2.95Ca_0.05Zr₂O₁₂XRD pattern of (a). From fig. 2 it can be seen that the individual peaks at different sintering times correspond approximately to the cubic phase diagram spectrum. In each group of samples between 27 and 30 degrees, only the (400) peak exists, and no (004) peak exists, so that the main crystal phases of the samples obtained in example 1 are all cubic phase structures.

FIG. 3 shows an oxide type solid electrolyte thin film Li of example 1_6.6Al_0.15La_2.95Ca_0.05Zr₂O₁₂SEM image of (d). As shown in fig. 3, from left to right are electron micrographs of the sample taken at 1000 and 2000 times, respectively. It can be seen that the grain distribution is relatively uniform, which means that the sample has good conductivity properties.

FIG. 4 is a view showing an oxide type solid electrolyte membraneLi_6.6Al_0.15La_2.95Ca_0.05Zr₂O₁₂EIS spectra at different test temperatures; the ionic conductivity can reach 4.76 multiplied by 10 at room temperature by calculation^-6S/cm。

Referring to the preparation process of example 1, samples of solid electrolyte thin films of examples 2 to 6 were prepared, respectively, by adjusting the use amounts of lithium nitrate, lanthanum nitrate hexahydrate, and calcium nitrate tetrahydrate, and replacing aluminum nitrate nonahydrate with gallium nitrate or ferric nitrate, with the other preparation steps being the same as those of example 1.

Serial number	Chemical formula of product	Li	La	Zr	Al	Ga	Ca	Fe
									Example 1	Li6.6Al0.15La2.95Ca0.05Zr2O12	6.60	2.95	2.00	0.15	0	0.05	0
Example 2	Li6.55Al0.15La3Zr2O12	6.55	3.00	2.00	0.15	0	0	0
									Example 3	Li6.55Ga0.15La3Zr2O12	6.55	3.00	2.00	0	0.15	0	0
Example 4	Li6.55Fe0.15La3Zr2O12	6.55	3.00	2.00	0	0	0	0.15
									Example 5	Li6.6Ga0.15La2.95Ca0.05Zr2O12	6.60	2.95	2.00	0	0.15	0.05	0
Example 6	Li6.6Fe0.15La2.95Ca0.05Zr2O12	6.60	2.95	2.00	0	0	0.05	0.15

Example 2: the chemical general formula of the oxide electrolyte film with high ionic conductivity is Li by doping Al element alone_6.55Al_0.15La₃Zr₂O₁₂The raw material used is LiNO₃、La(NO₃)₃、ZrO(NO₃)₂、Al(NO₃)₃And (3) powder.

Example 3: the Ga element is singly doped, and the chemical general formula of the oxide electrolyte film with high ionic conductivity is Li_6.55Ga_0.15La₃Zr₂O₁₂The raw material used is LiNO₃、La(NO₃)₃、ZrO(NO₃)₂、Ga(NO₃)₃And (3) powder.

Example 4: the chemical general formula of the oxide electrolyte film with high ionic conductivity is Li by doping Fe element alone_6.55Fe_0.15La₃Zr₂O₁₂The raw material used is LiNO₃、La(NO₃)₃、ZrO(NO₃)₂、Fe(NO₃)₃And (3) powder.

Example 5: the chemical general formula of the oxide electrolyte film with high ionic conductivity is Li by double doping Ga element and Ca element_6.6Ga_0.15La_2.95Ca_0.05Zr₂O₁₂The raw material used is LiNO₃、La(NO₃)₃、ZrO(NO₃)₂、Ga(NO₃)₃、Ca(NO₃)₂And (3) powder.

Example 6: the chemical general formula of the oxide electrolyte film with high ionic conductivity is Li by double doping Fe element and Ca element_6.6Fe_0.15La_2.95Ca_0.05Zr₂O₁₂The raw material used is LiNO₃、La(NO₃)₃、ZrO(NO₃)₂、Fe(NO₃)₃、Ca(NO₃)₂And (3) powder.

FIG. 5 shows an oxide type solid electrolyte thin film Li of example 5_6.6Ga_0.15La_2.95Ca_0.05Zr₂O₁₂EIS spectra at different test temperatures; the ionic conductivity can reach 2.28 multiplied by 10 at room temperature by calculation^-5S/cm。

FIG. 6 shows an oxide type solid electrolyte thin film Li of example 6_6.6Fe_0.15La_2.95Ca_0.05Zr₂O₁₂EIS spectra at different test temperatures; the ionic conductivity can reach 1.14 multiplied by 10 at room temperature by calculation^-6S/cm。

Comparative example 1

On the basis of the embodiment 1, the preparation process of the water-based precursor solution is not changed, the ultrasonic spraying instrument is not adopted for spraying, the solution is attached to the surface of the silicon substrate in a spin coating mode, the silicon substrate with the solution coated on the surface is placed into a muffle furnace for sintering, and the sintering process is not changed. The precursor solution can not be uniformly attached to the surface of the silicon substrate, and compared with ultrasonic spraying, the macroscopic and microscopic performances of the obtained electrolyte are reduced.

Comparative example 2

On the basis of the embodiment 1, the preparation process of the water-based precursor solution is not changed, an ultrasonic spraying instrument is not adopted for spraying, the solution is attached to the surface of the silicon substrate in a dip coating mode, the silicon substrate with the solution coated on the surface is placed into a muffle furnace for sintering, and the sintering process is not changed. Similarly to comparative example 1, the precursor solution did not uniformly adhere to the surface of the silicon substrate, and the obtained electrolyte exhibited degradation in macroscopic and microscopic properties as compared with ultrasonic spraying.

Comparative example 3

On the basis of example 1, the spraying cycle number is adjusted to be two (four layers), and the water-based precursor solution cannot be completely attached to the surface of the silicon substrate.

Comparative example 4

On the basis of example 1, the spraying cycle number is adjusted to four times (eight layers), and the water-based precursor solution can be gathered on the surface of the silicon substrate and cannot be uniformly distributed.

Comparative example 5

On the basis of the embodiment 1, the sintering temperature is adjusted to 1300 ℃, the silicon substrate deforms, the film forming of the water-based precursor solution on the surface is not facilitated, and the conductivity of the film is reduced.

Comparative example 6

On the basis of example 1, the sintering temperature was adjusted to 800 ℃, the reaction was incomplete, the desired pure phase of the sample could not be completely formed, various impure phases were generated, and the sample performance was not good.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (10)

1. A method for producing an oxide type solid electrolyte film, characterized by comprising the steps of:

(1) preparation of a water-based precursor solution:

mixing lithium salt, lanthanum salt, zirconium salt, aluminum salt, calcium salt, citric acid, ethylene glycol, binder and surfactant with deionized water, stirring and heating to prepare 0.11-0.13mol/L precursor solution, wherein the chemical general formula of the precursor is Li_{6.55+ x}Al_0.15La_3-xCa_xZr₂(OH)₂₄X is 0 to 0.15; the molar ratio of the lithium salt to the citric acid to the ethylene glycol is 1: 0.09-0.11: 0.9-1.1;

(2) adding the precursor solution prepared in the step (1) into an injector of an ultrasonic spraying instrument, placing the cut silicon substrate on a sample platform of the ultrasonic spraying instrument, spraying the silicon substrate at the flow rate of 0.008-0.011ml/min, opening the sample platform, heating to 110-;

(3) sintering the silicon substrate sprayed in the step (2), heating to 1095-1105 ℃ at the heating rate of 2.8-3.2 ℃/min, preserving the heat, and naturally cooling to room temperature to obtain Li_6.55+xAl_0.15La_3-xCa_xZr₂O₁₂A solid electrolyte membrane.

2. The method according to claim 1, wherein the aluminum salt is replaced with an equimolar amount of a gallium salt to produce Li_6.55+xGa_0.15La_3-xCa_xZr₂O₁₂A solid electrolyte film; or the aluminum salt is replaced by an equimolar amount of an iron salt to produce Li_6.55+xFe_0.15La_3-xCa_xZr₂O₁₂A solid electrolyte membrane.

3. The method of producing an oxide-type solid electrolyte film according to claim 1, wherein, in the step (1), the lithium salt is lithium nitrate, the lanthanum salt is lanthanum nitrate hexahydrate, the zirconium salt is zirconyl nitrate, the aluminum salt is aluminum nitrate nonahydrate, and the calcium salt is calcium nitrate tetrahydrate or anhydrous calcium nitrate;

the binder is a binding agent SPEEK-PSI-Li; the surfactant is a surfactant

F127。

4. The method for producing an oxide type solid electrolyte thin film according to claim 1, wherein in the step (1), the binder and the surfactant are each 9.8 to 10.2% by mass of the total mass of the precursor solution.

5. The method for producing an oxide type solid electrolyte thin film according to claim 1, wherein in the step (1), the temperature of the stirring heating is 85 to 95 ℃.

6. The method for preparing an oxide-type solid electrolyte membrane according to claim 1, wherein in the step (2), the treatment time of heating 445-455 ℃ on the magnetic stirrer is 5-6 min.

7. The method for producing an oxide type solid electrolyte thin film according to claim 1, wherein in the step (2), the precursor solution is added to a syringe of an ultrasonic spray coater in a volume of 9 to 10 ml.

8. The method for producing an oxide type solid electrolyte membrane according to claim 1, wherein the holding time in step (3) is 1 to 3 hours.

9. The method of an oxide-type solid electrolyte membrane according to claim 1, characterized by comprising the steps of: (1) preparation of a water-based precursor solution:

taking lithium nitrate, lanthanum nitrate hexahydrate, zirconyl nitrate, aluminum nitrate nonahydrate, calcium nitrate tetrahydrate, citric acid, glycol, a binding agent SPEEK-PSI-Li and a surfactant

F127, mixing with deionized water, stirring and heating to prepare 0.12mol/L precursor solution, wherein the chemical general formula of the precursor is Li_6.55+xAl_0.15La_3-xCa_xZr₂(OH)₂₄X is 0 to 0.15; the molar ratio of the lithium salt to the citric acid to the ethylene glycol is 1: 0.1: 1;

(2) adding the precursor solution prepared in the step (1) into an injector of an ultrasonic spraying instrument, placing the cut silicon substrate on a sample platform of the ultrasonic spraying instrument, spraying the silicon substrate at the flow rate of 0.01ml/min, opening the sample platform, heating to 120 ℃, spraying for three times, wherein each time comprises transverse spraying one layer and longitudinal spraying one layer, spraying for six layers for three times, and placing the silicon substrate on a magnetic stirrer after each spraying for heating at 450 ℃ for 5 min;

(3) sintering the silicon substrate sprayed in the step (2), heating to 1100 ℃ at the heating rate of 3 ℃/min, preserving heat for 1h, and naturally cooling to room temperature to obtain the target product Li_6.55+xAl_0.15La_3-xCa_xZr₂O₁₂。

10. An oxide-type solid electrolyte thin film produced by the method for producing an oxide-type solid electrolyte thin film according to any one of claims 1 to 9.

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