Amorphous high-entropy fluorine ion solid electrolyte material and preparation method and application thereof

Abstract

The invention belongs to the field of materials, and relates to an amorphous high-entropy fluorine ion solid electrolyte material and a preparation method and application thereof. The chemical formula of the amorphous high-entropy fluorine ion solid electrolyte material is AM < x > EM < y > RM < z > F < x + 2y + 3z >, wherein AM is a alkali metal elements with different compositions, EM is b alkaline earth metal elements with different compositions, and RM is c rare earth metal elements with different compositions; 0 < = a < = 5, 0 < = b < = 5, 0 < = c < = 5, a + b + c = N and N > = 5; x is equal to a / N, y is equal to b / N, z is equal to c / N, and subscripts corresponding to the AM, EM and RM are all 1 / N.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of materials, and particularly relates to a fluorine ion battery solid electrolyte material and a preparation method and application thereof, and particularly relates to an amorphous high-entropy fluorine ion solid electrolyte material and a preparation method and application thereof. BACKGROUND

[0002] New energy materials and battery technology are key fields related to national security and economic development, and are important levers for achieving the strategic goals of "carbon peak and carbon neutralization" and high-quality green development. Traditional cation secondary batteries such as lithium batteries, sodium batteries and potassium batteries have the advantage of high energy density, but they use organic electrolyte, which has inherent safety hazards. The most representative energy storage battery, lithium ion battery, is prone to severe electrode-electrolyte side reactions and internal short circuits caused by separator thermal deformation at high temperatures above 60°C, which has huge safety hazards and cannot meet the future requirements of high-tech equipment in wide temperature range, especially in high temperature. Solid-state lithium batteries have high safety in theory, but in practice, they still face problems such as lithium dendrite puncture leading to battery failure and poor intrinsic thermal stability of some solid electrolytes. Therefore, it is urgent to develop innovative and disruptive wide-temperature-range, high-specific-energy and intrinsically safe energy storage technologies and key material basic research to enhance China's self-reliance in new energy materials and battery technology and ensure national energy security.

[0003] Solid-state fluorine ion batteries are a new type of anion battery different from traditional cation batteries represented by lithium / sodium batteries, i.e. using negative fluorine ions as carriers to shuttle between the positive electrode-solid electrolyte-negative electrode of the secondary "rocking chair battery", which has the characteristics of wide temperature range, high specific energy and intrinsic safety. The advantages of fluorine ion batteries include: (1) energy density: the theoretical energy density can be as high as 5000 Wh / L, about 8 times that of current lithium ion batteries; (2) wide temperature range safety: fluorine is the most electronegative element and is difficult to form elemental fluorine in electrochemical reaction, and the negative electrode has no dendrite, which has intrinsic safety (especially the highest high-temperature safety up to ~200°C), far superior to commercial lithium ion batteries; (3) low cost and environmental friendliness: fluorine raw materials are abundant in the earth's crust, about 50 times that of lithium, with a cost of less than 1 / 2 of lithium batteries and environmental friendliness. However, fluorine ion batteries are still limited by the problems such as insufficient energy storage activity and poor reversibility of electrode materials, mutual restriction of ion conductivity and voltage window of solid-state electrolyte, and poor compatibility of multi-level interfaces, which cannot break through the preparation of high-specific-energy fluorine ion batteries.

[0004] It is of great significance to develop solid-state fluoride ion battery technology to seize the commanding heights of key materials and key technologies for the power supply demand of high-tech equipment in wide temperature range applications, especially high temperature applications. At present, European and American countries are leading in fluoride ion battery research: Germany developed a high fluoride ion conductivity solid electrolyte and a 160°C high-temperature rechargeable solid-state fluoride ion battery (J. Mater. Chem. 2011, 21, 17059-17062.), with a specific energy of about 230 Wh / kg; The United States and Japan jointly developed the first liquid rechargeable fluoride ion battery, and the related paper was published in Science (Science 2018, 362, 1144-1148.); Japan's RISING3 project allocates 2.5 billion yen to focus on fluoride ion batteries. In recent years, scientific research institutions represented by the Shanghai Institute of Ceramics of the Chinese Academy of Sciences (Adv Energy Mater 2023, 13, 2203168.), China University of Science and Technology (Small 2022, 18, 2104508.) and Xiangtan University (Ceram. Int. 2020, 46, 20521-20528.) in China have also carried out related research on solid-state fluoride ion batteries, but there is still a certain gap, and it is urgent to carry out full-chain research on solid-state fluoride ion battery energy storage new concepts-high-capacity electrodes and solid-state electrolyte new materials-wide temperature range high-specific-energy solid-state fluoride ion new devices to form a leading advantage in China in the field of wide temperature range high-safety high-specific-energy batteries.

[0005] Existing fluoride ion battery electrolytes mainly include liquid electrolytes and solid electrolytes, among which liquid electrolytes include ether electrolytes of tetraalkylammonium fluoride salt, borane+CsF+tetraglycol, tetramethylammonium bromide+methylpropylpiperidine bis(trifluoromethylsulfonyl) imide ionic liquid, etc., but these organic electrolytes have certain safety hazards. Solid electrolytes include RE 1- x AE x F 3-x (RE=La,Ce,Sm;AE=Ba,Sr,Ca)、MSnF4(M=Pb,Ba,Ca,Sr)、Ba 1-x Sb x F 2+x , fluoride or salt-doped PEG / PEO, etc.

[0006] Therefore, the solid-state fluorine ion battery has the potential of high theoretical energy density and high safety, but is still limited by the following problems of the fluorine ion solid-state electrolyte to be solved: (1) low fluorine ion conductivity of the fluorine ion solid-state electrolyte; (2) poor electrochemical stability and narrow voltage window of part of the fluorine ion solid-state electrolyte; (3) poor high-temperature stability of part of the fluorine ion solid-state electrolyte; (4) poor multi-level interface compatibility and high interface impedance of the fluorine ion solid-state electrolyte; and (5) complicated preparation process and high cost of the fluorine ion solid-state electrolyte. SUMMARY

[0007] Based on the problems of the fluorine ion solid-state electrolyte, the purpose of the present application is to provide an amorphous high-entropy fluorine ion solid electrolyte material, a preparation method and application thereof.

[0008] In a first aspect, the present application provides an amorphous high-entropy fluorine ion solid electrolyte material, the chemical formula of the amorphous high-entropy fluorine ion solid electrolyte material is AM x EM y RM z F x+2y+3z ; wherein AM is a kind of different composition of alkali metal element, EM is b kind of different composition of alkaline earth metal element, RM is c kind of different composition of rare earth metal element; 0≤a≤5, 0≤b≤5, 0≤c≤5, a+b+c=N and N≥5; x=a / N, y=b / N, z=c / N and the subscript of each AM, EM and RM is 1 / N.

[0009] In the present application, the fluorine ion solid electrolyte material has a high-entropy chemical composition, i.e. more than 5 kinds of metal elements in the composition and all of them are strong alkali metals, alkaline earth metals or rare earth metals, which is beneficial to reduce the electronic conductivity of the material, improve the stability and high-temperature stability of the electrochemical process of the material, and realize the stability of the wide voltage window. Moreover, the amorphous structure, i.e. long-range disorder and short-range order structure, can break through the limitation of traditional crystal lattice on ion transmission, couple the high-entropy composition to reduce the fluorine ion transmission energy barrier, and improve the fluorine ion conductivity of the material. In addition, the amorphous structure has excellent interface compatibility in the crystal boundary, multi-level interface of the solid electrolyte / positive and negative electrode materials, can significantly reduce the crystal impedance and interface impedance, and realizes the high-performance fluorine ion solid-state electrolyte.

[0010] Preferably, the alkali metal elements include Li, Na, K, Rb and Cs. The alkaline earth metal elements include Be, Mg, Ca, Sr and Ba.

[0011] Preferably, the rare earth metal elements include Y, La, Ce, Pr, Nd, Sm, Eu, Gd and Er.

[0012] Preferably, the amorphous high-entropy fluoride ion solid electrolyte material is in an amorphous structure; the amorphous high-entropy fluoride ion solid electrolyte material is in a powder form with a particle size of 0.1 nm to 100 nm; and the amorphous high-entropy fluoride ion solid electrolyte material is an oligomer.

[0013] Preferably, the fluoride ion conductivity of the amorphous high-entropy fluoride ion solid electrolyte material is 0.1 to 15 mS / cm, and the electronic conductivity is 0.01 to 5 μS / cm.

[0014] In a second aspect, the present application provides a preparation method of an amorphous high-entropy fluoride ion solid electrolyte material, comprising: (1) dissolving soluble salts of AM elements, soluble salts of EM elements, and soluble salts of RM elements in an organic solvent to obtain a first mixed solution; (2) dissolving a soluble fluoride salt in an organic solvent, and then adding a small-molecule organic amine as an end-capping group to inhibit crystal growth to obtain a second mixed solution; (3) mixing the first mixed solution and the second mixed solution to undergo a co-precipitation reaction, and then separating, washing, and drying to obtain a precipitate; (4) heat-treating the obtained precipitate at 100 to 900°C to obtain the amorphous high-entropy fluoride ion solid electrolyte material.

[0015] Preferably, in step (1), the soluble salt of the AM element is at least one of a chloride, a sulfate, a nitrate, a carbonate, and an acetate of the AM element; the soluble salt of the EM element is at least one of a chloride, a sulfate, a nitrate, a carbonate, and an acetate of the EM element; the soluble salt of the RM element is at least one of a chloride, a sulfate, a nitrate, a carbonate, and an acetate of the RM element; the organic solvent is at least one of methanol, ethanol, isopropanol, butanol, acetone, dimethylformamide, acetonitrile, ethyl acetate, and diethyl ether.

[0016] Preferably, in step (2), the soluble fluoride salt includes one of NH4F and fluorosilicic acid; the ratio of the amount of substance of fluoride ions in the soluble fluoride salt to the total amount of substance of AM ions, EM ions, and RM ions in the first mixed solution is (1 to 4):1; and the organic solvent is at least one of methanol, ethanol, isopropanol, butanol, acetone, dimethylformamide, acetonitrile, ethyl acetate, and diethyl ether. the small-molecule organic amine is at least one of ethylenediamine, triethylamine, diethanolamine, and triethanolamine; and the ratio of the small-molecule organic amine to the soluble fluoride salt is (1 to 10) mL:1 mmol.

[0017] Preferably, in step (3), the drying method comprises drying at 0-60℃ or freeze-drying at -60-0℃.

[0018] Preferably, in step (4), the heat treatment is performed for 4-24 hours at a temperature of 100-600℃.

[0019] In a third aspect, the present application provides a method for preparing a solid electrolyte ceramic sheet, comprising: pressing an amorphous high-entropy fluoride ion solid electrolyte material into a sheet to obtain the solid electrolyte ceramic sheet.

[0020] In a fourth aspect, the present application provides a solid electrolyte ceramic sheet prepared by the method described above, wherein the thickness of the solid electrolyte ceramic sheet is 0.1-3mm.

[0021] In a fifth aspect, the present application provides a solid electrolyte membrane, comprising: a polymer matrix, and a solid electrolyte material prepared from an amorphous high-entropy fluoride ion solid electrolyte material dispersed in the polymer matrix. Preferably, the thickness of the solid electrolyte membrane is 0.1-1cm. Preferably, the polymer matrix comprises at least one of PEO, PDOL, PVDF and PTFE. Preferably, the solid electrolyte material prepared from the amorphous high-entropy fluoride ion solid electrolyte material is in powder form, with a particle size of 0.1-100nm and a content of 50-95wt%.

[0022] In a sixth aspect, the present application provides a fluoride ion battery, comprising: a solid electrolyte ceramic sheet or a solid electrolyte membrane as a solid electrolyte.

[0023] The present application has the following advantages: In the present application, the special high-entropy composition of the amorphous high-entropy fluoride ion solid electrolyte material introduces chemical disorder (amorphous) and the resulting distortion, which locally disturbs the site energy, thereby widening the distribution of site energy and promoting fluoride ion hopping. If this network of sites with similar energy penetrates, the macroscopic ion diffusion will be enhanced by disorder. The introduction of local distortion of high-entropy materials leads to the overlapping distribution of fluoride ion potential, thereby low activation energy transmission, improving the ability of solid-state electrolyte fluoride ion conductivity and reducing the dependence on specific chemicals and enhancing the synthetic ability. The amorphous high-entropy fluoride ion solid electrolyte combines the advantages of high fluoride ion conductivity at room temperature (≥0.5mS / cm), low electronic conductivity (≤10μS / cm), wide voltage window (≥4V) and high temperature stability (≥200℃) and low interface impedance, greatly increasing its usability in advanced solid-state fluoride ion batteries and greatly promoting the development of new high-specific-energy high-safety solid-state fluoride ion batteries. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 Mg 1 / 7 Ca 1 / 7 Sr 1 / 7 Ba 1 / 7 Y 1 / 7 La 1 / 7 Ce 1 / 7 F 17 / 7 X-ray powder diffraction pattern of Mg Figure 2 Mg 1 / 7 Ca 1 / 7 Sr 1 / 7 Ba 1 / 7 Y 1 / 7 La 1 / 7 Ce 1 / 7 F 17 / 7 X-ray powder diffraction pattern after annealing at 200°C Figure 3 Mg 1 / 7 Ca 1 / 7 Sr 1 / 7 Ba 1 / 7 Y 1 / 7 La 1 / 7 Ce 1 / 7 F 17 / 7 Scanning electron microscope image of Mg Figure 4 Mg 1 / 7 Ca 1 / 7 Sr 1 / 7 Ba 1 / 7 Y 1 / 7 La 1 / 7 Ce 1 / 7 F 17 / 7 Elemental mapping of Mg Figure 5 Mg 1 / 7 Ca 1 / 7 Sr 1 / 7 Ba 1 / 7 Y 1 / 7 La 1 / 7 Ce 1 / 7 F 17 / 7 Impedance spectroscopy of solid electrolyte sheet Figure 6 Mg 1 / 7 Ca 1 / 7 Sr 1 / 7 Ba 1 / 7 Y 1 / 7 La 1 / 7 Ce 1 / 7 F 17 / 7 Current-time (I-T) curve of electronic conductivity test of solid electrolyte sheet Figure 7 Mg prepared in Example 1 1 / 7 Ca 1 / 7 Sr 1 / 7 Ba 1 / 7 Y 1 / 7 La 1 / 7 Ce 1 / 7 F 17 / 7 Linear scan curve (LSV) for electrochemical window testing of solid electrolyte sheets; Figure 8 Mg prepared in Example 1 1 / 7 Ca 1 / 7 Sr 1 / 7 Ba 1 / 7 Y 1 / 7 La 1 / 7 Ce 1 / 7 F 17 / 7 Room temperature constant current charge-discharge curves of solid electrolytes used in fluoride-ion solid-state batteries. Detailed Implementation

[0025] The present invention will be further illustrated by the following embodiments. It should be understood that the following embodiments are for illustrative purposes only and are not intended to limit the present invention.

[0026] In this invention, the general structural formula of the amorphous high-entropy fluoride ion solid electrolyte material is AM. x EM y RM z F x+2y+3z Where AM is an alkali metal, EM is an alkaline earth metal, RM is a rare earth metal, and F is fluorine, and the following requirements must be met: 1) AM is an alkali metal element selected from Li, Na, K, Rb and Cs; 2) EM is an alkaline earth metal element selected from Be, Mg, Ca, Sr and Ba; 3) RM is a rare earth metal element selected from Y, La, Ce, Pr, Nd, Sm, Eu, Gd and Er; 4) The amorphous high-entropy fluoride contains more than 5 kinds of metal elements.

[0027] The amorphous high-entropy fluoride ion solid electrolyte material described in this invention is an amorphous high-entropy fluoride with an amorphous amorphous structure. This amorphous high-entropy fluoride exhibits excellent fluoride ion conductivity and is a type of solid electrolyte capable of conducting fluoride ions.

[0028] The following exemplarily illustrates a method for preparing liquid-phase oligomers of amorphous high-entropy fluoride ion solid electrolyte materials.

[0029] Weigh at least five soluble salts of the required AM, EM, and RM elements in proportion and dissolve them in an organic solvent to obtain solution 1. The organic solvent is selected from one or more of methanol, ethanol, isopropanol, butanol, acetone, dimethylformamide, acetonitrile, ethyl acetate, and diethyl ether.

[0030] Excess soluble fluoride salt is dissolved in an organic solvent, and a small-molecule organic amine is added as a capping group to inhibit crystal growth, yielding solution 2. The organic solvent is selected from one or more of methanol, ethanol, isopropanol, butanol, acetone, dimethylformamide, acetonitrile, ethyl acetate, and diethyl ether. The small-molecule organic amine is one or more of ethylenediamine, triethylamine, diethanolamine, or triethanolamine.

[0031] When solutions 2 and 1 are mixed, a co-precipitation reaction occurs, yielding a precipitate. In this precipitate, the small-molecule organic amine moves faster than other fluoride ions towards a high-concentration aggregate of metal fluoride ions, preemptively occupying favorable positions for further aggregation or growth, thus blocking the aggregation of fluorides and forming inorganic ionic oligomers.

[0032] The precipitate is separated, washed, and dried (e.g., dried at 60°C or freeze-dried), and finally annealed at a high temperature of 100°C-900°C to obtain an amorphous high-entropy fluoride.

[0033] This disclosure also provides applications of amorphous high-entropy fluoride-ion solid electrolyte materials. Specifically, the amorphous high-entropy fluoride-ion solid electrolyte material is prepared into solid electrolyte ceramic sheets by powder pressing, or compounded with organic polymers such as PEO, PDOL, PVDF, and PTFE to form solid electrolyte membranes for use in solid-state fluoride-ion batteries.

[0034] Sample characterization: The morphology and composition information of the samples were collected using a scanning electron microscope, and the structural information of the samples was collected using an X-ray diffractometer.

[0035] Performance testing: The ionic conductivity, electronic conductivity, and electrochemical window of the solid electrolyte were characterized using the AutoLab series electrochemical workstations from Metrohm (Switzerland) and the CHI series electrochemical workstations from Shanghai Chenhua. The performance of the fluorine battery was characterized using the Blue Battery Testing System.

[0036] The following examples further illustrate the present invention in detail. It should also be understood that the following examples are only for further explanation of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above description of the present invention are within the scope of protection of the present invention. The specific process parameters, etc., in the following examples are merely examples within a suitable range; that is, those skilled in the art can make appropriate selections within the appropriate range based on the description herein, and are not intended to be limited to the specific values ​​in the examples below.

[0037] Example 1 Mg 1 / 7 Ca 1 / 7 Sr 1 / 7 Ba 1 / 7 Y 1 / 7 La 1 / 7 Ce 1 / 7 F 17 / 7 The synthesis uses CaCl2, SrCl2, MgCl2, BaCl2, YCl3, LaCl3, CeCl3, and NH4F as raw materials. First, prepare solution S1: Add 1 mmol each of CaCl2, SrCl2, MgCl2, BaCl2, YCl3, LaCl3, and CeCl3 to a beaker, then add 60 mL of methanol. Mix the methanol with the metal salts, ensuring complete dissolution to form a homogeneous metal salt solution. Prepare solution S2: Add 17 mmol of NH4F (10% excess), 40 mL of methanol, and 2 mL of triethylamine to a beaker. Mix and dissolve completely at room temperature to obtain an NH4F solution. Then, add the NH4F solution from S2 to the homogeneously dissolved S1 metal salt solution. Stir at room temperature until the reaction is complete. After the reaction, filter the solution, wash twice with methanol and ethanol, and then dry the solid translucent product at 60 °C or freeze-dry to obtain an amorphous high-entropy white fluoride powder. XRD patterns of the product obtained by drying at 60℃ and the product after heat treatment at 200℃ are shown below. Figure 1 and 2 As shown, both are amorphous, exhibiting only broad peaks associated with fluorite and cerium fluoride structures, indicating that the material possesses thermal stability above 200℃. (Scanning electron microscopy) Figure 3 The material appears to consist of irregular small particles, which agglomerate to form micron-sized large particles. The elements Mg, Ca, Sr, Ba, Y, La, Ce, and F are evenly distributed. Figure 4 The powder, containing Mg, Ca, Sr, Ba, Y, La, and Ce elements in a ratio close to 1, was prepared according to the same feeding ratio. The resulting powder was then pressed into thin circular discs with a diameter of 8 mm and a thickness of 0.5-1 mm using a ~100 MPa high-pressure mold. Both sides were fitted with stainless steel blocking electrodes. Fluoride ion conductivity and electronic conductivity were then tested. Figure 5 The electrochemical impedance spectroscopy (EIS) spectrum shown indicates that the fluoride ion conductivity of this electrolyte is ~2.3 mS / cm. For example... Figure 6 The current-time (IT) curve of the solid electrolyte disc shows that its electronic conductivity is 0.12 μS / cm. The solid electrolyte disc is flanked by a SnF2-Sn-C non-blocking electrode and a Mg electrode, respectively. 1 / 7 Ca 1 / 7 Sr 1 / 7 Ba 1 / 7 Y1 / 7 La 1 / 7 Ce 1 / 7 F 17 / 7 A circular electrode of the same diameter as the (50wt%)-C (50wt%) blocking electrode was used to test the linear sweep voltammetry (LSV) curve of the solid electrolyte sheet. The electrochemical stability range was found to be -2.8V to 1.2V, with a voltage window of 4V. Figure 7 A symmetrical fluorine-ion solid-state battery was constructed by replacing both sides of the solid electrolyte disc with non-blocking SnF2-Sn-C discs of the same diameter. The constant current charge-discharge curves of the solid electrolyte disc were tested at room temperature (25℃) and 0.1C rate. Figure 8 It was discovered that it can achieve normal charging and discharging, making it the world's first room-temperature rechargeable solid-state fluoride-ion battery. When the battery is placed in a 200°C constant temperature chamber, it can operate stably without catching fire or exploding.

[0038] Example 2 Na 1 / 7 K 1 / 7 Rb 1 / 7 Cs 1 / 7 Y 1 / 7 La 1 / 7 Ce 1 / 7 F 13 / 7The synthesis uses NaCl, KCl, RbCl, CsCl, YCl3, LaCl3, CeCl3, and NH4F as raw materials. First, prepare solution S1: Add 1 mmol each of NaCl, KCl, RbCl, CsCl, YCl3, LaCl3, and CeCl3 to a beaker, then add 60 mL of methanol. Mix the methanol with the metal salts, ensuring complete dissolution to form a homogeneous metal salt solution. Prepare solution S2: Add 17 mmol of NH4F, 40 mL of methanol, and 2 mL of triethylamine to a beaker, and mix until completely dissolved at room temperature to obtain an NH4F solution. Then, add the NH4F solution from S2 to the homogeneously dissolved S1 metal salt solution. Stir at room temperature until the reaction is complete. After the reaction, filter the solution, wash twice with methanol and ethanol, then dry the solid translucent product at 60 °C or freeze-dry it, and heat-treat at 100 °C for 4 hours to obtain an amorphous high-entropy white fluoride powder. Scanning electron microscopy revealed that the material consisted of irregular small particles with uniform elemental distribution, and the proportion of metal elements was close to 1, consistent with the initial feed ratio. The obtained powder was pressed into thin discs with a diameter of 8 mm and a thickness of 0.5-1 mm using a ~100 MPa high-pressure mold. Both sides were fitted with stainless steel blocking electrodes. Fluoride ion conductivity and electronic conductivity were tested. Electrochemical impedance spectroscopy (EIS) showed that the fluoride ion conductivity of the electrolyte was ~1.5 mS / cm. The current-time (IT) curve of the solid electrolyte disc indicated an electronic conductivity of 0.1 μS / cm. Using discs of the same diameter with SnF2-Sn-C non-blocking electrodes on one side and solid electrolyte (50 wt%)-C (50 wt%) blocking electrodes on the other, the linear sweep spectroscopy (LSV) curve of the solid electrolyte disc was tested, revealing a voltage window of 7 V. By replacing both sides of the solid electrolyte disc with discs of the same diameter containing SnF2-Sn-C non-blocking electrodes, a symmetrical fluoride-ion solid battery was constructed, and it was found that it could achieve normal charging and discharging at temperatures ranging from 25℃ to 200℃.

[0039] Example 3 Na 1 / 7 K 1 / 7 Rb 1 / 7 Cs 1 / 7 Ca 1 / 7 Sr 1 / 7 Ba 1 / 7 F 13 / 7The synthesis uses NaCl, KCl, RbCl, CsCl, CaCl2, SrCl2, BaCl2, and NH4F as raw materials. First, prepare solution S1: Add 1 mmol each of NaCl, KCl, RbCl, CsCl, CaCl2, SrCl2, and BaCl2 to a beaker, then add 60 mL of methanol. Mix the methanol with the metal salts, ensuring complete dissolution to form a homogeneous metal salt solution. Prepare solution S2: Add 17 mmol of NH4F, 40 mL of methanol, and 2 mL of triethylamine to a beaker. Mix and dissolve completely at room temperature to obtain an NH4F solution. Then, add the NH4F solution from S2 to the homogeneously dissolved S1 metal salt solution. Stir at room temperature until the reaction is complete. After the reaction, filter the solution, wash twice with methanol and ethanol, then dry the semi-transparent solid product at 60°C or freeze-dry it, and heat-treat at 100°C for 4 hours to obtain an amorphous high-entropy white fluoride powder. Scanning electron microscopy revealed that the material consisted of irregular small particles with uniform elemental distribution, and the proportion of metal elements was close to 1, consistent with the initial feed ratio. The obtained powder was pressed into thin discs with a diameter of 8 mm and a thickness of 0.5–1 mm using a ~100 MPa high-pressure mold. Both sides were fitted with stainless steel blocking electrodes. Fluoride ion conductivity and electronic conductivity were tested. Electrochemical impedance spectroscopy (EIS) showed that the fluoride ion conductivity of the electrolyte was ~1.5 mS / cm. The current-time (IT) curve of the solid electrolyte disc indicated an electronic conductivity of 0.1 μS / cm. Using discs of the same diameter with SnF2-Sn-C non-blocking electrodes on one side and solid electrolyte (50 wt%)-C (50 wt%) blocking electrodes on the other, the linear sweep spectroscopy (LSV) curve of the solid electrolyte disc was tested, revealing a voltage window of 7 V. By replacing both sides of the solid electrolyte disc with discs of the same diameter containing SnF2-Sn-C non-blocking electrodes, a symmetrical fluoride-ion solid battery was constructed, and it was found that it could achieve normal charging and discharging at temperatures ranging from 25℃ to 200℃.

[0040] Example 4 Ca 1 / 6 Sr 1 / 6 Ba 1 / 6 Y 1 / 6 La 1 / 6 Ce 1 / 6 F 2.5The synthesis uses CaCl2, SrCl2, BaCl2, YCl3, LaCl3, CeCl3, and NH4F as raw materials. First, solution S1 is prepared: 1 mmol each of CaCl2, SrCl2, BaCl2, YCl3, LaCl3, and CeCl3 are added to a beaker, followed by 60 mL of methanol. The methanol is then mixed with the metal salts, ensuring complete dissolution to form a homogeneous metal salt solution. Next, solution S2 is prepared: 18 mmol of NH4F, 40 mL of methanol, and 2 mL of triethylamine are added to a beaker and mixed at room temperature until completely dissolved to obtain an NH4F solution. Then, the NH4F solution from S2 is added to the homogeneously dissolved metal salt solution from S1. The mixture is stirred at room temperature until the reaction is complete. After the reaction, the solution is filtered, washed twice with methanol and ethanol, and then the solid translucent product is dried at 60 °C or freeze-dried, followed by heat treatment at 100 °C for 4 hours to obtain an amorphous high-entropy white fluoride powder. Scanning electron microscopy revealed that the material consisted of irregular small particles with uniform elemental distribution, and the proportion of metal elements was close to 1, consistent with the initial feed ratio. The obtained powder was pressed into thin discs with a diameter of 8 mm and a thickness of 0.5-1 mm using a ~100 MPa high-pressure mold. Both sides were fitted with stainless steel blocking electrodes. Fluoride ion conductivity and electronic conductivity were tested. Electrochemical impedance spectroscopy (EIS) showed that the fluoride ion conductivity of the electrolyte was ~2.0 mS / cm. The current-time (IT) curve of the solid electrolyte disc indicated an electronic conductivity of 0.7 μS / cm. Using discs of the same diameter with SnF2-Sn-C non-blocking electrodes on one side and solid electrolyte (50 wt%)-C (50 wt%) blocking electrodes on the other, the linear sweep spectroscopy (LSV) curve of the solid electrolyte disc was tested, revealing a voltage window of 5 V. By replacing both sides of the solid electrolyte disc with discs of the same diameter containing SnF2-Sn-C non-blocking electrodes, a symmetrical fluoride-ion solid battery was constructed, and it was found that it could achieve normal charging and discharging at temperatures ranging from 25℃ to 200℃.

[0041] Example 5 Ca 1 / 5 Sr 1 / 5 Y 1 / 5 La 1 / 5 Ce 1 / 5 F 13 / 5The synthesis uses CaCl2, SrCl2, YCl3, LaCl3, CeCl3, and NH4F as raw materials. First, solution S1 is prepared: 1 mmol each of CaCl2, SrCl2, YCl3, LaCl3, and CeCl3 are added to a beaker, followed by 60 mL of methanol. The methanol is then mixed with the metal salts, ensuring complete dissolution to form a homogeneous metal salt solution. Next, solution S2 is prepared: 17 mmol of NH4F, 40 mL of methanol, and 2 mL of triethylamine are added to a beaker and mixed at room temperature until completely dissolved to obtain an NH4F solution. Then, the NH4F solution from S2 is added to the homogeneously dissolved S1 metal salt solution. The mixture is stirred at room temperature until the reaction is complete. After the reaction, the solution is filtered, washed twice with methanol and ethanol, and then the solid translucent product is dried at 60 °C or freeze-dried, followed by heat treatment at 100 °C for 4 hours to obtain an amorphous high-entropy white fluoride powder. Scanning electron microscopy revealed that the material consisted of irregular small particles with uniform elemental distribution, and the proportion of metal elements was close to 1, consistent with the initial feed ratio. The obtained powder was pressed into thin discs with a diameter of 8 mm and a thickness of 0.5-1 mm using a ~100 MPa high-pressure mold. Both sides were fitted with stainless steel blocking electrodes. Fluoride ion conductivity and electronic conductivity were tested. Electrochemical impedance spectroscopy (EIS) showed that the fluoride ion conductivity of the electrolyte was ~0.5 mS / cm. The current-time (IT) curve of the solid electrolyte disc indicated an electronic conductivity of 0.5 μS / cm. Using discs of the same diameter with SnF2-Sn-C non-blocking electrodes on one side and solid electrolyte (50 wt%)-C (50 wt%) blocking electrodes on the other, the linear sweep spectroscopy (LSV) curve of the solid electrolyte disc was tested, revealing a voltage window of 4.5 V. By replacing both sides of the solid electrolyte disc with discs of the same diameter containing SnF2-Sn-C non-blocking electrodes, a symmetrical fluoride-ion solid battery was constructed, and it was found that it could achieve normal charging and discharging at temperatures ranging from 25℃ to 200℃.

[0042] Example 6 K 1 / 5 Cs 1 / 5 Y 1 / 5 La 1 / 5 Ce 1 / 5 F 13 / 5The synthesis uses KCl, CsCl, YCl3, LaCl3, CeCl3, and NH4F as raw materials. First, prepare solution S1: Add 1 mmol each of KCl, CsCl, YCl3, LaCl3, and CeCl3 to a beaker, then add 60 mL of methanol. Mix the methanol with the metal salts, ensuring complete dissolution to form a homogeneous metal salt solution. Prepare solution S2: Add 17 mmol of NH4F, 40 mL of methanol, and 2 mL of triethylamine to a beaker. Mix and dissolve completely at room temperature to obtain an NH4F solution. Then, add the NH4F solution from S2 to the homogeneously dissolved metal salt solution from S1. Stir at room temperature until the reaction is complete. After the reaction, filter the solution, wash twice with methanol and ethanol, then dry the semi-transparent solid product at 60 °C or freeze-dry it, and heat-treat at 100 °C for 4 hours to obtain an amorphous high-entropy white fluoride powder. Scanning electron microscopy revealed that the material consisted of irregular small particles with uniform elemental distribution, and the proportion of metal elements was close to 1, consistent with the initial feed ratio. The obtained powder was pressed into thin discs with a diameter of 8 mm and a thickness of 0.5-1 mm using a ~100 MPa high-pressure mold. Both sides were fitted with stainless steel blocking electrodes. Fluoride ion conductivity and electronic conductivity were tested. Electrochemical impedance spectroscopy (EIS) showed that the fluoride ion conductivity of the electrolyte was ~0.8 mS / cm. The current-time (IT) curve of the solid electrolyte disc indicated an electronic conductivity of 0.8 μS / cm. Using discs of the same diameter with SnF2-Sn-C non-blocking electrodes on one side and solid electrolyte (50 wt%)-C (50 wt%) blocking electrodes on the other, the linear sweep spectroscopy (LSV) curve of the solid electrolyte disc was tested, revealing a voltage window of 5.5 V. By replacing both sides of the solid electrolyte disc with discs of the same diameter containing SnF2-Sn-C non-blocking electrodes, a symmetrical fluoride-ion solid battery was constructed, and it was found that it could achieve normal charging and discharging at temperatures ranging from 25℃ to 200℃.

[0043] Example 7 Be 1 / 5 Mg 1 / 5 Ca 1 / 5 Sr 1 / 5 Ba 1 / 5The synthesis of F2 uses BeCl2, MgCl2, CaCl2, SrCl2, BaCl2, and NH4F as raw materials. First, S1 solution is prepared: 1 mmol each of BeCl2, MgCl2, CaCl2, SrCl2, and BaCl2 are added to a beaker, followed by 60 mL of methanol. The methanol is then mixed with the metal salts, ensuring complete dissolution to form a homogeneous metal salt solution. Next, S2 solution is prepared: 17 mmol of NH4F, 40 mL of methanol, and 2 mL of triethylamine are added to a beaker and mixed at room temperature until completely dissolved to obtain an NH4F solution. Then, the NH4F solution from S2 is added to the homogeneously dissolved S1 metal salt solution. The mixture is stirred at room temperature until the reaction is complete. After the reaction, the solution is filtered, washed twice with methanol and ethanol, and then the solid translucent product is dried at 60°C or freeze-dried, followed by heat treatment at 100°C for 4 hours to obtain an amorphous high-entropy white fluoride powder. Scanning electron microscopy revealed that the material consisted of irregular small particles with uniform elemental distribution, and the proportion of metal elements was close to 1, consistent with the initial feed ratio. The obtained powder was pressed into thin discs with a diameter of 8 mm and a thickness of 0.5-1 mm using a ~100 MPa high-pressure mold. Both sides were fitted with stainless steel blocking electrodes. Fluoride ion conductivity and electronic conductivity were tested. Electrochemical impedance spectroscopy (EIS) showed that the fluoride ion conductivity of the electrolyte was ~0.6 mS / cm. The current-time (IT) curve of the solid electrolyte disc indicated an electronic conductivity of 0.5 μS / cm. Using discs of the same diameter with SnF2-Sn-C non-blocking electrodes on one side and solid electrolyte (50 wt%)-C (50 wt%) blocking electrodes on the other, the linear sweep spectroscopy (LSV) curve of the solid electrolyte disc was tested, revealing a voltage window of 5.5 V. By replacing both sides of the solid electrolyte disc with discs of the same diameter containing SnF2-Sn-C non-blocking electrodes, a symmetrical fluoride-ion solid battery was constructed, and it was found that it could achieve normal charging and discharging at temperatures ranging from 25℃ to 200℃.

[0044] Example 8 Li 1 / 5 Na 1 / 5 K 1 / 5 Rb 1 / 5 Cs 1 / 5The synthesis of F uses LiCl, NaCl, KC, RbCl, CsCl, and NH4F as raw materials. First, solution S1 is prepared: 1 mmol each of LiCl, NaCl, KC, RbCl, and CsCl are added to a beaker, followed by 60 mL of methanol. The methanol is then mixed with the metal salts, ensuring complete dissolution to form a homogeneous metal salt solution. Solution S2 is prepared: 17 mmol NH4F, 40 mL methanol, and 2 mL triethylamine are added to a beaker and mixed at room temperature until completely dissolved to obtain an NH4F solution. The NH4F solution from S2 is then added to the homogeneously dissolved metal salt solution from S1. The mixture is stirred at room temperature until the reaction is complete. After the reaction, the solution is filtered and washed twice with methanol and ethanol. The solid, translucent product is then dried at 60°C or freeze-dried, followed by heat treatment at 100°C for 4 hours to obtain an amorphous high-entropy fluoride white powder. Scanning electron microscopy shows that the material consists of irregular small particles with a uniform distribution of elements, with the metal element ratio close to 1, consistent with the feed ratio. The obtained powder was pressed into thin discs with a diameter of 8 mm and a thickness of 0.5-1 mm using a ~100 MPa high-pressure mold. Both sides were fitted with stainless steel blocking electrodes. The fluoride ion conductivity and electronic conductivity were tested. Electrochemical impedance spectroscopy (EIS) showed that the fluoride ion conductivity of the electrolyte was ~0.9 mS / cm. The current-time (IT) curve of the solid electrolyte disc showed that its electronic conductivity was 0.1 μS / cm. Using discs of the same diameter with SnF2-Sn-C non-blocking electrodes on one side and solid electrolyte (50 wt%)-C (50 wt%) blocking electrodes on the other, the linear sweep spectroscopy (LSV) curve of the solid electrolyte disc was tested, revealing a voltage window of 8 V. Replacing both sides of the solid electrolyte disc with SnF2-Sn-C non-blocking electrodes created a symmetrical fluoride ion solid-state battery, which was found to achieve normal charge and discharge at temperatures ranging from 25℃ to 200℃.

[0045] Example 9 Y 1 / 5 La 1 / 5 Ce 1 / 5 Pr 1 / 5 Nd 1 / 5The synthesis of F3 uses YCl3, LaCl3, CeCl3, PrCl3, NdCl3, and NH4F as raw materials. First, solution S1 is prepared: 1 mmol each of YCl3, LaCl3, CeCl3, PrCl3, and NdCl3 are added to a beaker, followed by 60 mL of methanol. The methanol is then mixed with the metal salts, ensuring complete dissolution to form a homogeneous metal salt solution. Solution S2 is prepared: 17 mmol of NH4F, 40 mL of methanol, and 2 mL of triethylamine are added to a beaker and mixed at room temperature until completely dissolved to obtain an NH4F solution. Then, the NH4F solution from S2 is added to the homogeneously dissolved metal salt solution from S1. The mixture is stirred at room temperature until the reaction is complete. After the reaction, the solution is filtered, washed twice with methanol and ethanol, and then the solid translucent product is dried at 60°C or freeze-dried, followed by heat treatment at 100°C for 4 hours to obtain an amorphous high-entropy white fluoride powder. Scanning electron microscopy revealed that the material consisted of irregular small particles with uniform elemental distribution, and the proportion of metal elements was close to 1, consistent with the initial feed ratio. The obtained powder was pressed into thin discs with a diameter of 8 mm and a thickness of 0.5-1 mm using a ~100 MPa high-pressure mold. Both sides were fitted with stainless steel blocking electrodes. Fluoride ion conductivity and electronic conductivity were tested. Electrochemical impedance spectroscopy (EIS) showed that the fluoride ion conductivity of the electrolyte was ~1.5 mS / cm. The current-time (IT) curve of the solid electrolyte disc indicated an electronic conductivity of 3 μS / cm. Using discs of the same diameter with SnF2-Sn-C non-blocking electrodes on one side and solid electrolyte (50 wt%)-C (50 wt%) blocking electrodes on the other, the linear sweep spectroscopy (LSV) curve of the solid electrolyte disc was tested, revealing a voltage window of 4 V. By replacing both sides of the solid electrolyte disc with discs of the same diameter containing SnF2-Sn-C non-blocking electrodes, a symmetrical fluoride-ion solid battery was constructed, and it was found that it could achieve normal charging and discharging at temperatures ranging from 25℃ to 200℃.

[0046] Example 10 Y 1 / 9 La 1 / 9 Ce 1 / 9 Pr 1 / 9 Nd 1 / 9 Sm 1 / 9 Eu 1 / 9 Gd 1 / 9 Er 1 / 9The synthesis of F3 uses YCl3, LaCl3, CeCl3, PrCl3, NdCl3, SmCl3, EuCl3, GdCl3, ErCl3, and NH4F as raw materials. First, prepare solution S1: Add 1 mmol each of YCl3, LaCl3, CeCl3, PrCl3, NdCl3, SmCl3, EuCl3, GdCl3, and ErCl3 to a beaker, then add 60 mL of methanol. Mix the methanol with the metal salts, ensuring complete dissolution to form a homogeneous metal salt solution. Prepare solution S2: Add 27 mmol of NH4F, 40 mL of methanol, and 2 mL of triethylamine to a beaker, and mix until completely dissolved at room temperature to obtain an NH4F solution. Then, add the NH4F solution from S2 to the homogeneously dissolved metal salt solution from S1. Stir at room temperature until the reaction is complete. After the reaction, the solution was filtered and washed twice with methanol and ethanol. The solid, translucent product was then dried at 60°C or freeze-dried, followed by heat treatment at 100°C for 4 hours to obtain an amorphous high-entropy fluoride white powder. Scanning electron microscopy showed that the material consisted of irregular small particles with uniform elemental distribution, and the proportion of metal elements was close to 1, consistent with the feed ratio. The obtained powder was pressed into thin discs with a diameter of 8 mm and a thickness of 0.5-1 mm using a ~100 MPa high-pressure mold. Both sides were fitted with stainless steel blocking electrodes, and the fluoride ion conductivity and electronic conductivity were tested. Electrochemical impedance spectroscopy (EIS) showed that the fluoride ion conductivity of the electrolyte was ~5 mS / cm. The current-time (IT) curve of the solid electrolyte disc showed that its electronic conductivity was 5 μS / cm. By using two discs of the same diameter, one with a SnF2-Sn-C non-blocking electrode and the other with a solid electrolyte (50wt%)-C (50wt%) blocking electrode, and testing the linear sweep voltammetry (LSV) curve of the solid electrolyte disc, a voltage window of 4V was obtained. Replacing both sides of the solid electrolyte disc with discs of the same diameter containing SnF2-Sn-C non-blocking electrodes, a symmetrical fluorine-ion solid-state battery was constructed, and it was found that it could achieve normal charge and discharge at temperatures ranging from 25℃ to 200℃.

[0047] Example 11 Mg 1 / 13 Ca 1 / 13 Sr 1 / 13 Ba 1 / 13 Y 1 / 13 La 1 / 13 Ce 1 / 13 Pr 1 / 13 Nd 1 / 13 Sm 1 / 13 Eu 1 / 13 Gd 1 / 13 Er 1 / 13 F 35 / 13The synthesis uses MgCl2, CaCl2, SrCl2, BaCl2, YCl3, LaCl3, CeCl3, PrCl3, NdCl3, SmCl3, EuCl3, GdCl3, ErCl3, and NH4F as raw materials. First, prepare solution S1: Add 1 mmol each of MgCl2, CaCl2, SrCl2, BaCl2, YCl3, LaCl3, CeCl3, PrCl3, NdCl3, SmCl3, EuCl3, GdCl3, and ErCl3 to a beaker, then add 60 mL of methanol. Mix the methanol with the metal salts, ensuring complete dissolution to form a homogeneous metal salt solution. Next, prepare solution S2: Add 39 mmol of NH4F, 40 mL of methanol, and 2 mL of triethylamine to a beaker, and mix until completely dissolved at room temperature to obtain an NH4F solution. Then, add the NH4F solution from S2 to the homogeneously dissolved metal salt solution from S1. The mixture was stirred at room temperature until the reaction was complete. After the reaction, the solution was filtered and washed twice with methanol and ethanol. The solid translucent product was then dried at 60°C or freeze-dried, and heat-treated at 100°C for 4 hours to obtain an amorphous high-entropy white fluoride powder. Scanning electron microscopy showed that the material consisted of irregular small particles with uniform elemental distribution, and the proportion of metal elements was close to 1, consistent with the feed ratio. The obtained powder was pressed into thin discs with a diameter of 8 mm and a thickness of 0.5-1 mm using a ~100 MPa high-pressure mold. Both sides were fitted with stainless steel blocking electrodes, and the fluoride ion conductivity and electronic conductivity were tested. Electrochemical impedance spectroscopy (EIS) showed that the fluoride ion conductivity of the electrolyte was ~7 mS / cm. The current-time (IT) curve of the solid electrolyte disc showed that its electronic conductivity was 4 μS / cm. By using two discs of the same diameter, one with a SnF2-Sn-C non-blocking electrode and the other with a solid electrolyte (50wt%)-C (50wt%) blocking electrode, and testing the linear sweep voltammetry (LSV) curve of the solid electrolyte disc, a voltage window of 5V was obtained. Replacing both sides of the solid electrolyte disc with discs of the same diameter containing SnF2-Sn-C non-blocking electrodes, a symmetrical fluorine-ion solid-state battery was constructed, and it was found that it could achieve normal charge and discharge at temperatures ranging from 25℃ to 200℃.

[0048] Example 12 K 1 / 16 Rb 1 / 16 Cs 1 / 16 Mg 1 / 16 Ca 1 / 16 Sr 1 / 16 Ba 1 / 16 Y 1 / 16 La 1 / 16 Ce 1 / 16 Pr 1 / 16 Nd 1 / 16 Sm 1 / 16 Eu 1 / 16Gd 1 / 16 Er 1 / 16 F 38 / 16 The synthesis uses KCl, RbCl, CsCl, MgCl2, CaCl2, SrCl2, BaCl2, YCl3, LaCl3, CeCl3, PrCl3, NdCl3, SmCl3, EuCl3, GdCl3, ErCl3, and NH4F as raw materials. First, prepare solution S1: Add 1 mmol each of KCl, RbCl, CsCl, MgCl2, CaCl2, SrCl2, BaCl2, YCl3, LaCl3, CeCl3, PrCl3, NdCl3, SmCl3, EuCl3, GdCl3, and ErCl3 to a beaker, then add 60 mL of methanol. Mix the methanol with the metal salts, ensuring complete dissolution to form a homogeneous metal salt solution. Next, prepare solution S2: Add 48 mmol of NH4F, 40 mL of methanol, and 2 mL of triethylamine to a beaker. Mix and dissolve completely at room temperature to obtain an NH4F solution. Then, the NH4F solution of S2 was added to the uniformly dissolved S1 metal salt solution. The mixture was stirred at room temperature until the reaction was complete. After the reaction, the solution was filtered, washed twice with methanol and ethanol, and then the solid translucent product was dried at 60℃ or freeze-dried, followed by heat treatment at 100℃ for 4 hours to obtain an amorphous high-entropy white fluoride powder. Scanning electron microscopy showed that the material consisted of irregular small particles with uniform elemental distribution, and the metal element ratio was close to 1, consistent with the feed ratio. The obtained powder was pressed into thin discs with a diameter of 8 mm and a thickness of 0.5-1 mm using a ~100 MPa high-pressure mold, with stainless steel blocking electrodes on both sides. The fluoride ion conductivity and electronic conductivity were tested. Electrochemical impedance spectroscopy (EIS) showed that the fluoride ion conductivity of the electrolyte was ~10 mS / cm. The current-time (IT) curve of the solid electrolyte disc showed that its electronic conductivity was 3 μS / cm. By using two discs of the same diameter, one with a SnF2-Sn-C non-blocking electrode and the other with a solid electrolyte (50wt%)-C (50wt%) blocking electrode, and testing the linear sweep voltammetry (LSV) curve of the solid electrolyte disc, a voltage window of 5.5V was obtained. Replacing both sides of the solid electrolyte disc with discs of the same diameter containing SnF2-Sn-C non-blocking electrodes, a symmetrical fluorine-ion solid-state battery was constructed, and it was found that it could achieve normal charge and discharge at temperatures ranging from 25℃ to 200℃.

[0049] Example 13 Li 1 / 19 Na 1 / 19 K 1 / 19 Rb 1 / 19 Cs 1 / 19 Be 1 / 19 Mg 1 / 19 Ca 1 / 19Sr. 1 / 19 nay 1 / 19 Y 1 / 19 to 1 / 19 What 1 / 19 Fr. 1 / 19 when 1 / 19 Sm 1 / 19 I 1 / 19 Gd 1 / 19 Err 1 / 19 F 42 / 19The synthesis uses LiCl, NaCl, KCl, RbCl, CsCl, BeCl2, MgCl2, CaCl2, SrCl2, BaCl2, YCl3, LaCl3, CeCl3, PrCl3, NdCl3, SmCl3, EuCl3, GdCl3, ErCl3, and NH4F as raw materials. First, prepare the S1 solution: add 1 mmol each of LiCl, NaCl, KCl, RbCl, CsCl, BeCl2, MgCl2, CaCl2, SrCl2, BaCl2, YCl3, LaCl3, CeCl3, PrCl3, NdCl3, SmCl3, EuCl3, GdCl3, and ErCl3 to a beaker, then add 60 mL of methanol. Mix the methanol with the metal salts, ensuring the metal salts are completely dissolved in the methanol to form a homogeneous metal salt mixture solution. Preparation of S2 solution: 57 mmol NH4F, 40 mL methanol, and 2 mL triethylamine were added to a beaker and mixed and completely dissolved at room temperature to obtain an NH4F solution. Then, the NH4F solution of S2 was added to a uniformly dissolved S1 metal salt solution. The mixture was stirred at room temperature until the reaction was complete. After the reaction, the solution was filtered and washed twice with methanol and ethanol. The solid translucent product was then dried at 60 °C or freeze-dried, and heat-treated at 100 °C for 4 hours to obtain an amorphous high-entropy white fluoride powder. Scanning electron microscopy showed that the material consisted of irregular small particles with uniform elemental distribution, and the metal element ratio was close to 1, consistent with the feed ratio. The obtained powder was pressed into thin discs with a diameter of 8 mm and a thickness of 0.5-1 mm using a ~100 MPa high-pressure mold, with stainless steel blocking electrodes on both sides. The fluoride ion conductivity and electronic conductivity were tested. Electron impedance spectroscopy (EIS) showed that the fluoride ion conductivity of this electrolyte was ~15 mS / cm. The current-time (IT) curve of the solid electrolyte disc showed an electronic conductivity of 3 μS / cm. By testing the linear sweep voltammetry (LSV) curve of the solid electrolyte disc with SnF2-Sn-C non-blocking electrodes on one side and solid electrolyte (50wt%)-C (50wt%) blocking electrodes on the other, a voltage window of 6V was obtained. Replacing both sides of the solid electrolyte disc with SnF2-Sn-C non-blocking electrodes of the same diameter to form a symmetrical fluoride-ion solid-state battery, it was found that it could achieve normal charge-discharge at temperatures ranging from 25℃ to 200℃.

[0050] Example 14 Ca 1 / 5 Sr 1 / 5 Y 1 / 5 La 1 / 5 Ce 1 / 5 F 13 / 5The synthesis uses Ca(NO3)2, Sr(NO3)2, Y(NO3)3, La(NO3)3, Ce(NO3)3, and NH4F as raw materials. First, prepare solution S1: Add 1 mmol each of Ca(NO3)2, Sr(NO3)2, Y(NO3)3, La(NO3)3, and Ce(NO3)3 to a beaker, then add 60 mL of methanol. Mix the methanol with the metal salts, ensuring complete dissolution to form a homogeneous metal salt solution. Next, prepare solution S2: Add 17 mmol of NH4F, 40 mL of methanol, and 2 mL of triethylamine to a beaker. Mix and dissolve completely at room temperature to obtain an NH4F solution. Then, add the NH4F solution from S2 to the homogeneously dissolved S1 metal salt solution. Stir at room temperature until the reaction is complete. After the reaction, the solution was filtered and washed twice with methanol and ethanol. The solid, translucent product was then dried at 60°C or freeze-dried, followed by heat treatment at 100°C for 4 hours to obtain an amorphous high-entropy white fluoride powder. Scanning electron microscopy showed that the material consisted of irregular small particles with uniform elemental distribution, and the proportion of metal elements was close to 1, consistent with the feed ratio. The obtained powder was pressed into thin discs with a diameter of 8 mm and a thickness of 0.5-1 mm using a ~100 MPa high-pressure mold. Both sides were fitted with stainless steel blocking electrodes, and the fluoride ion conductivity and electronic conductivity were tested. Electrochemical impedance spectroscopy (EIS) showed that the fluoride ion conductivity of the electrolyte was ~0.5 mS / cm. The current-time (IT) curve of the solid electrolyte disc showed that its electronic conductivity was 0.5 μS / cm. By using two discs of the same diameter, one with a SnF2-Sn-C non-blocking electrode and the other with a solid electrolyte (50wt%)-C (50wt%) blocking electrode, and testing the linear sweep voltammetry (LSV) curve of the solid electrolyte disc, a voltage window of 4.5V was obtained. Replacing both sides of the solid electrolyte disc with discs of the same diameter containing SnF2-Sn-C non-blocking electrodes, a symmetrical fluorine-ion solid-state battery was constructed, and it was found that it could achieve normal charge and discharge at temperatures ranging from 25℃ to 200℃.

[0051] Example 15 Ca 1 / 6 Sr 1 / 6 Ba 1 / 6 Y 1 / 6 La 1 / 6 Ce 1 / 6 F 2.5The synthesis uses CaCl2, SrCl2, BaCl2, YCl3, LaCl3, CeCl3, and NH4F as raw materials. First, solution S1 is prepared: 1 mmol each of CaCl2, SrCl2, BaCl2, YCl3, LaCl3, and CeCl3 are added to a beaker, followed by 60 mL of methanol. The methanol is then mixed with the metal salts, ensuring complete dissolution to form a homogeneous metal salt solution. Next, solution S2 is prepared: 18 mmol of NH4F, 40 mL of methanol, and 2 mL of triethylamine are added to a beaker and mixed at room temperature until completely dissolved to obtain an NH4F solution. Then, the NH4F solution from S2 is added to the homogeneously dissolved metal salt solution from S1. The mixture is stirred at room temperature until the reaction is complete. After the reaction, the solution is filtered, washed twice with methanol and ethanol, and then the solid translucent product is dried at 60 °C or freeze-dried, followed by heat treatment at 100 °C for 4 hours to obtain an amorphous high-entropy white fluoride powder. Scanning electron microscopy revealed that the material consisted of irregular small particles with uniform elemental distribution, and the proportion of metal elements was close to 1, consistent with the feed ratio. The obtained powder was thoroughly mixed with an NMP solution of PVDF at a solid electrolyte:PVDF mass ratio of 9:1. Solid electrolyte films with a thickness of approximately 10 μm-100 μm were prepared by casting or blade coating. The films were cut into discs with stainless steel blocking electrodes on both sides, and the fluoride ion conductivity and electronic conductivity were tested. Electrochemical impedance spectroscopy (EIS) showed that the fluoride ion conductivity of the electrolyte was ~1.2 mS / cm. The current-time (IT) curve of the solid electrolyte disc showed an electronic conductivity of 0.5 μS / cm. Using discs of the same diameter with SnF2-Sn-C non-blocking electrodes on one side and solid electrolyte (50 wt%)-C (50 wt%) blocking electrodes on the other, the linear sweep spectroscopy (LSV) curve of the solid electrolyte disc was tested, revealing a voltage window of 4 V. By replacing both sides of the solid electrolyte disc with discs of the same diameter containing SnF2-Sn-C non-blocking electrodes, a symmetrical fluorine-ion solid battery was constructed, and it was found that it could achieve normal charging and discharging at temperatures ranging from 25℃ to 200℃.

[0052] Comparative Example 1 In Comparative Example 1, MF was synthesized using a method similar to that used in the Examples. xM can be one (e.g., Y), two (e.g., Ba, Y), three (e.g., K, Ba, Y), or four (e.g., K, Ba, Y, La) of Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, and Er, respectively). First, prepare solution S1: Add 1 mmol of each of the above-mentioned metal chloride salts to a beaker, add 60 mL of methanol, and mix the methanol with the metal salts, ensuring the metal salts are completely dissolved in the methanol to form a homogeneous metal salt mixture. Next, prepare solution S2: Add 12 mmol of NH4F, 40 mL of methanol, and 2 mL of triethylamine to a beaker, and mix and dissolve completely at room temperature to obtain an NH4F solution. Then, add the NH4F solution of S2 to the homogeneously dissolved metal salt solution of S1. Stir at room temperature until the reaction is complete. After the reaction, the solution was filtered and washed twice with methanol and ethanol. The solid, translucent product was then dried at 60°C or freeze-dried, and heat-treated at 100°C for 4 hours to obtain a white fluoride powder. The obtained powder was pressed into thin discs with a diameter of 8 mm and a thickness of 0.5-1 mm using a ~100 MPa high-pressure mold. Both sides were fitted with stainless steel blocking electrodes. The fluoride ion conductivity and electronic conductivity were tested. Electrochemical impedance spectroscopy (EIS) showed that the fluoride ion conductivity of this electrolyte was ~10. -9 ~0.1 mS / cm. The current-time (IT) curve of the solid electrolyte sheet shows that its electronic conductivity is 0.0001-0.5 μS / cm. Using two discs of the same diameter with SnF2-Sn-C non-blocking electrodes on one side and solid electrolyte (50wt%)-C (50wt%) blocking electrodes on the other, the linear sweep voltammetry (LSV) curve of the solid electrolyte sheet was tested, revealing a voltage window of 2-10 V. Replacing both sides of the solid electrolyte disc with discs of the same diameter containing SnF2-Sn-C non-blocking electrodes to form a symmetrical fluoride-ion solid-state battery, it was found that it could not achieve normal charge-discharge at room temperature.

[0053] Comparative Example 2 In Comparative Example 2, commercially available fluorides or mixtures of one (e.g., Y), two (e.g., Ba, Y), three (e.g., K, Ba, Y), or four (e.g., K, Ba, Y, La) of Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, and Er were used. The multi-component mixture was mixed using a ball milling method. The resulting powder was pressed into thin discs with a diameter of 8 mm and a thickness of 0.5-1 mm using a ~100 MPa high-pressure mold, with stainless steel blocking electrodes on both sides. The fluoride ion conductivity and electronic conductivity were tested. Electrochemical impedance spectroscopy (EIS) showed that the fluoride ion conductivity of this electrolyte was ~10. -9~0.01 mS / cm. The current-time (IT) curve of the solid electrolyte sheet shows that its electronic conductivity is 0.0001~0.5 μS / cm. Using two discs of the same diameter with SnF2-Sn-C non-blocking electrodes on one side and solid electrolyte (50wt%)-C (50wt%) blocking electrodes on the other, the linear sweep voltammetry (LSV) curve of the solid electrolyte sheet was tested, revealing a voltage window of 2~10V. Replacing both sides of the solid electrolyte disc with discs of the same diameter containing SnF2-Sn-C non-blocking electrodes to form a symmetrical fluorine-ion solid-state battery, it was found that it could not achieve normal charge-discharge at room temperature.

[0054] Table 1:

Claims

1. An amorphous high-entropy fluoride-ion solid electrolyte material, characterized by, The chemical formula of the amorphous high-entropy fluorine ion solid electrolyte material is AM x EM y RM z F x+2y+3z ; wherein AM is a kind of different composition of alkali metal elements, EM is b different composition of alkaline earth metal elements, RM is c different composition of rare earth metal elements; 0≤a≤5, 0≤b≤5, 0≤c≤5, a+b+c=N and N≥5; x=a / N, y=b / N, z=c / N and the subscript corresponding to each AM, EM, RM is 1 / N.

2. The amorphous high-entropy fluoride-ion solid electrolyte material of claim 1, wherein The alkali metal elements include Li, Na, K, Rb and Cs; The alkaline earth metal elements include Be, Mg, Ca, Sr and Ba; The rare earth metal elements include Y, La, Ce, Pr, Nd, Sm, Eu, Gd and Er.

3. The amorphous high-entropy fluoride-ion solid electrolyte material according to claim 1 or 2, characterized in that, The amorphous high-entropy fluorine ion solid electrolyte material is in an amorphous structure; the amorphous high-entropy fluorine ion solid electrolyte material is in a powder form, and the particle size is 0.1 nm to 100 nm; and the amorphous high-entropy fluorine ion solid electrolyte material is an oligomer.

4. The amorphous high-entropy fluoride-ion solid electrolyte material of any one of claims 1-3, wherein, The fluorine ion conductivity of the amorphous high-entropy fluorine ion solid electrolyte material is 0.1 to 15 mS / cm, and the electronic conductivity is 0.01 to 5 μS / cm.

5. A method for producing the amorphous high-entropy fluoride-ion solid electrolyte material according to any one of claims 1 to 4, characterized by, The method comprises the following steps: (1) dissolving soluble salts of AM elements, EM elements and RM elements in an organic solvent to obtain a first mixed solution; (2) dissolving a soluble fluorine salt in an organic solvent, and then adding a small-molecule organic amine as an end-capping group to inhibit crystal growth to obtain a second mixed solution; (3) mixing the first mixed solution and the second mixed solution to generate a co-precipitation reaction, and then separating, washing and drying to obtain a precipitate; (4) heat-treating the obtained precipitate at 100 to 900 ℃ to obtain the amorphous high-entropy fluorine ion solid electrolyte material.

6. The preparation method according to claim 5, characterized in that, In step (1), the soluble salt of AM elements is at least one of a chloride, a sulfate, a nitrate, a carbonate and an acetate of AM elements; The soluble salt of EM elements is at least one of a chloride, a sulfate, a nitrate, a carbonate and an acetate of EM elements; The soluble salt of RM elements is at least one of a chloride, a sulfate, a nitrate, a carbonate and an acetate of RM elements; The organic solvent is at least one of methanol, ethanol, isopropanol, butanol, acetone, dimethylformamide, acetonitrile, ethyl acetate and diethyl ether.

7. The production method according to claim 5 or 6, characterized by, In step (2), the soluble fluorine salt includes one of NH4F and fluorosilicic acid; the ratio of the amount of substance of fluorine ions in the soluble fluorine salt to the total amount of substance of AM ions, EM ions and RM ions in the first mixed solution is (1 to 4):1; The organic solvent is at least one of methanol, ethanol, isopropanol, butanol, acetone, dimethylformamide, acetonitrile, ethyl acetate and diethyl ether; The small-molecule organic amine is at least one of ethylenediamine, triethylamine, diethanolamine and triethanolamine; the ratio of the small-molecule organic amine to the soluble fluorine salt is (1 to 10) mL:1 mmol.

8. The production method according to any one of claims 5 to 7, characterized by, In step (3), the drying method includes drying at 0 to 60 ℃ or freeze-drying at -60 to 0 ℃.

9. The production method according to any one of claims 5 to 8, characterized by, In step (4), the heat treatment time is 4 to 24 hours; preferably, the heat treatment temperature is 100 to 600 ℃.

10. A method of producing a solid electrolytic ceramic sheet, characterized by, The method comprises the following steps: The amorphous high-entropy fluorine ion solid electrolyte material of claim 1 is pressed into a sheet to obtain the solid electrolyte ceramic sheet.

11. A solid electrolytic ceramic sheet produced by the production method according to claim 10, characterized by The thickness of the solid electrolyte ceramic sheet is 0.1 mm to 3 mm.

12. A solid electrolyte membrane, characterized by, The method comprises the following steps: The polymer matrix and the solid electrolyte material prepared from the amorphous high-entropy fluorine ion solid electrolyte material of claim 1 are dispersed in the polymer matrix. Preferably, the thickness of the solid electrolyte film is 0.1mm-1mm; Preferably, the polymer matrix comprises at least one of PEO, PDOL, PVDF and PTFE; Preferably, the amorphous high-entropy fluorine ion solid electrolyte material is prepared into a powder, the particle size is 0.1nm-100nm, and the content is 50-95wt%.

13. A fluoride ion battery, characterized by, Comprise: The solid electrolyte ceramic sheet of claim 11 or the solid electrolyte film of claim 12 as a solid electrolyte.

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