Fluorine-containing compound solid electrolyte, method for producing same, and battery

Abstract

To provide a fluorine-containing compound solid electrolyte having high ion conductivity, a method for producing the same, and a battery.SOLUTION: The general structural formula of the solid electrolyte with relatively high ionic conductivity is (AX) aMBy, wherein A is at least one of Li, Na, K, Ag and Cu; M is at least one of Ti, Sn, Ta, N, Zr, Hf, Ga, Al and Fe, 0.5 <a <4, B is at least one of F and Cl, X is at least one of oxygen-containing anion and fluorine-containing anion, y is 4 or 5, or B is at least one of F, Cl, Br and I, X is BF4, y is 3 or 4 or 5.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present application belongs to the technical field of battery materials, and in particular relates to a fluorine-containing compound solid electrolyte, a method for producing the same, and a battery. [Background technology]

[0002] To meet consumer demand for electronic products, battery energy density must be further increased to reduce the number of charging cycles for devices such as power tools and mobile power supplies, thereby extending the battery's service life. Improving battery charging voltage is an important way to improve energy density. However, improving charging voltage also poses challenges to the electrolyte's redox resistance. Liquid electrolytes are limited by the oxidation limit of approximately 4.3 V for carbonate-based solvents, and electrolyte additives can only slightly improve the electrolyte's high-pressure resistance. Fluoride solid electrolytes have a wide electrochemical stability window, making them compatible with relatively high-voltage cathodes and promising for realizing all-solid-state batteries with higher energy densities. However, the ionic conductivity of fluoride electrolytes is generally below 10 -8 S cm -1 Therefore, there has been no fluoride electrolyte suitable for all-solid-state battery systems to date, and the development of a fluoride solid electrolyte with high ionic conductivity is an urgent issue that needs to be resolved. Summary of the Invention [Problem to be solved by the invention]

[0003] The present application provides a fluorine-containing compound solid electrolyte, a method for producing the same, and a battery, which aim to solve the problem of relatively low ionic conductivity of fluoride electrolytes. [Means for solving the problem]

[0004] In order to achieve the above object of the application, the technical solution adopted by this application is as follows:

[0005] According to a first aspect, the present application provides a fluorine-containing compound solid electrolyte, and the general structural formula is (AX) a MB y where A is at least one of Li, Na, K, Ag, and Cu; M is at least one of Ti, Sn, Ta, Nb, Zr, Hf, Ga, Al, and Fe; 0.5 < a < 4; B is F; X is at least one of an oxygen-containing anion and a fluorine-containing anion; y is 4 or 5; or B is at least one of F, Cl, Br, and I; X is BF4; and y satisfies 3, 4, or 5.

[0006] According to a second aspect, the present application provides a method for manufacturing a fluorine-containing compound solid electrolyte. This method involves subjecting AX powder and MB[[ID=⑨]] y powder in a stoichiometric ratio to a solid-phase reaction by mechanical ball milling in an anhydrous and oxygen-free inert atmosphere to obtain a fluorine-containing compound solid electrolyte (AX) a MB y .

[0007] According to a third aspect, the present application provides a battery including the above-mentioned fluorine-containing compound solid electrolyte.

[0008] The present application forms an open-frame structure by connecting X anions and transition metal-halogen ion polyhedra, establishing a cross-linked network skeleton and a penetrating three-dimensional channel, and filling A ions into the pores therein. Such a design can achieve rapid conduction of A ions in a structure having a large free volume, and the solid electrolyte according to the examples of the present application has a relatively high ionic conductivity. Fluoride ions have a high electronegativity (for example, the oxidation potential limit of perfluorinated compound electrolytes is much higher than that of sulfide electrolytes and halide electrolytes). By developing using fluoride-containing electrolyte materials, all-solid-state batteries of 6 V or more can be realized, which are compatible with more high-energy-density cathode materials. [[ID=⑳]]

Brief Description of the Drawings

[0009] In order to more clearly explain the technical solutions in the embodiments of the present application, the following will briefly describe the drawings that need to be used in the embodiments or the prior art description. It is obvious that the drawings in the following description are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on the structures shown in these drawings without exerting any creative effort. [Figure 1] 1 is an electrochemical impedance spectrum of (Li3PO4)TiF4 synthesized in Example 1. [Figure 2] 1 shows X-ray diffraction spectra of the (LiBF)2TaCl5, (LiBF4)3TaCl5, and (LiBF4)TaCl5 halogen-boron fluorine compound solid electrolytes synthesized in Examples 6 to 8. In the figure, the horizontal axis represents the diffraction angle (2 Theta) in degrees (°), and the vertical axis represents the diffraction intensity. [Figure 3] 1 shows the X-ray diffraction spectrum of the (Li3PO4)TiF4 solid electrolyte synthesized in Example 1. In the figure, the horizontal axis represents the diffraction angle (2 Theta) in degrees (°), and the vertical axis represents the diffraction intensity. [Figure 4] 1 shows linear scan curves for the solid electrolyte (LiBF)TaCl according to Example 6 of the present application and the solid electrolyte LiZrCl according to Comparative Example 3. Here, the horizontal axis represents voltage in volts (V), and the vertical axis represents current density in milliamperes per gram (mA g). [Figure 5] 1 shows linear scan curves for the (LiPO)TiF solid electrolyte synthesized in Example 1 of the present application and the LiZrCl solid electrolyte synthesized in Comparative Example 3. Here, the horizontal axis represents voltage in volts (V), and the vertical axis represents current density in milliamperes per gram (mA g). [Figure 6] 1 shows charge-discharge curves for the first three cycles at a 0.3 C rate of the all-solid-state lithium battery assembled in Example 8 of the present application. In the figure, the horizontal axis represents specific capacity in milliampere-hours per gram (mAh g), and the vertical axis represents voltage relative to Li / Li in volts (V). [Figure 7] 1 shows charge-discharge curves for the first three cycles at a 0.3 C rate of the all-solid-state lithium battery assembled in Example 9 of the present application. In the figure, the horizontal axis represents specific capacity in milliampere-hours per gram (mAh g), and the vertical axis represents voltage relative to Li / Li in volts (V). DETAILED DESCRIPTION OF THE INVENTION

[0010] In order to make the technical problems, technical solutions and beneficial effects solved by the embodiments of the present application clearer, the following will be described in more detail in conjunction with the embodiments and drawings. It should be understood that the specific embodiments described herein are only for interpreting the present application, and are not intended to limit the present application.

[0011] In this application, the term "and / or" describes a relationship between related objects and indicates that three relationships may exist. For example, A and / or B may represent three cases: A alone, A and B in combination, and B alone. Here, A and B may be singular or plural. The character " / " generally indicates that the related objects before and after it are in an "or" relationship.

[0012] As used herein, "at least one" refers to one or more, and "plurality" refers to two or more. "At least one of" or similar expressions refers to any combination of those items, including any combination of single items or multiple items. For example, "at least one of a, b, or c" or "at least one of a, b, and c" can each refer to a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c may each be singular or plural.

[0013] It should be understood that in various embodiments of the present application, the magnitude of the numbers of the above-mentioned respective processes does not mean the order of execution before or after. Some or all of the steps may be executed in parallel or in sequence before or after, and the order of execution of each process should be determined by its function and internal logic, and does not constitute any limitation to the implementation process of the embodiments of the present application.

[0014] The terms used in the embodiments of the present application are only for describing specific embodiments and are not intended to limit the present application. The singular forms "one", "the above-mentioned" and "said" used in the embodiments of the present application and the appended patent claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0015] The weight of the related components mentioned in the specification of the embodiments of the present application not only refers to the specific content of each component, but may also represent the weight ratio relationship between each component. Therefore, as long as the content of the related components expands or shrinks proportionally according to the specification of the embodiments of the present application, they are all within the scope disclosed in the specification of the embodiments of the present application. Specifically, the mass described in the specification of the embodiments of the present application may be a mass unit known in the chemical industry field such as μg, mg, g, kg, etc.

[0016] The first aspect of the embodiments of the present application provides a fluorine-containing compound solid electrolyte, and the general structural formula is (AX) a MB y where A is at least one of Li, Na, K, Ag and Cu, M is at least one of Ti, Sn, Ta, Nb, Zr, Hf, Ga, Al and Fe, 0.5 < a < 4, and B is F, X is at least one of an oxygen-containing anion and a fluorine-containing anion, y is 4 or 5, or B is at least one of F, Cl, Br and I, X is BF4, and y satisfies 3 or 4 or 5.

[0017] The fluorine-containing compound solid electrolyte according to the embodiments of the present application mainly includes two types.

[0018] One type has a general structural formula of (AX) a MF y where A is at least one of Li, Na, K, Ag, and Cu; M is at least one of Ti, Sn, Ta, Nb, Zr, Hf, Ga, Al, and Fe; X is at least one of an oxygen-containing anion and a fluorine-containing anion; 0.5 < a < 4; and y is 4 or 5. It can be named a perfluorinated compound solid electrolyte.

[0019] Another type has a general structural formula of (ABF4) a MB y where A is at least one of Li, Na, K, Ag, and Cu; M is at least one of Ti, Sn, Ta, Nb, Zr, Hf, Ga, Al, and Fe; B is at least one of F, Cl, Br, and I; 0.5 < a < 4; and y is 3, 4, or 5. It can be named a halogen-boron fluoride compound solid electrolyte. In the formula, "B" in "BF4" represents boron, and "B" in "MB y " represents at least one of F, Cl, Br, and I.

[0020] Here, X is at least one of an oxygen-containing anion and a fluorine-containing anion, and may include one or more of the oxygen-containing anions, or one or more of the fluorine-containing anion groups, or a combination of one or more of the oxygen-containing anions and one or more of the fluorine-containing anions.

[0021] In the examples of this application, the X anion, MB<A y is a transition metal-halogen ion polyhedron.

[0022] In the examples of the present application, an open-frame structure is constructed by connecting X anions with transition metal-halide ion polyhedra, establishing a cross-linked network framework and three-dimensional penetrating channels, allowing A ions to fill the vacancies therein. This design allows A ions to conduct rapidly in a structure with a large free volume, and the solid electrolytes according to the examples of the present application have relatively high ionic conductivity.

[0023] Fluoride ions have a high electronegativity (for example, the oxidation potential limit of perfluorinated electrolytes is much higher than that of sulfide and halide electrolytes), and by developing fluoride-containing electrolyte materials, all-solid-state batteries of 6 V or higher can be realized, which are compatible with many high-energy density cathode materials.

[0024] In some embodiments, the general structural formula is (AX) a MB y wherein A is Li, M is at least one of Zr, Hf, Ta, Nb, Al, Fe, and Ga, B is at least one of F, Cl, Br, and I, X is BF4, and y is 3 or 4, or 0.5 <a<4である。

[0025] In the examples of the present application, the general structural formula is (AX) a MF y and can be named a perfluoro compound solid electrolyte.

[0026] In some embodiments, the general structural formula is (AX) a MB y wherein A is at least one of Li, Na, K, Ag, and Cu; M is at least one of Ti, Sn, Ta, Nb, Zr, Hf, and Ga; B is F; X is at least one of an oxygen-containing anion and a fluorine-containing anion; y is 4 or 5, and 0.5 <a<4である。

[0027] In the examples of the present application, the general structural formula is (AX) a MBy and can be named a halogen-boron fluorine compound solid electrolyte.

[0028] In some embodiments, the oxygen-containing anions include at least one of O, O2, CO3, PO4, SO4, SiO3, NO3, MoO3, WO3, B4O7, and P2O7, and / or the fluorine-containing anions include at least one of BF4, PF6, and AsF6.

[0029] In some embodiments, the X anions in the fluorine-containing compound solid electrolyte are linked to the transition metal-halogen ion polyhedron to form an open-frame structure, and the A ions fill the voids of the open frame.

[0030] The first type of fluorine-containing compound solid electrolyte (AX) a MF y In contrast, this material system is composed of X anions and fluorinated transition metal polyhedra (MF y ) to form an open-frame structure, and A ions fill the pores of this open frame to obtain a specific glass-ceramic phase, which realizes rapid ionic conduction, with an ionic conductivity of greater than 0.1 mS / cm at 60°C. The glass phase and glass-ceramic interface are the main mechanisms for rapid ionic conduction within this specific glass-ceramic phase structure.

[0031] The second type of fluorine-containing compound solid electrolyte (ABF4) a MB y In contrast, this material system is composed of BF4 tetrahedrons and transition metal-halide ion polyhedra MB y The glass-ceramic interface is the primary mechanism for rapid ion conduction within this specific glass-ceramic phase structure.

[0032] In some embodiments, it further contains an auxiliary additive, and the mass of the auxiliary additive satisfies 0 < w% ≤ 20%.

[0033] To further improve its electrochemical performance, an additive of specific components may be added to the glass phase and the ceramic phase in a manner of composite, chemical combination, solid solution, or mixing. The additive may further contain one or a combination of a plurality of elements such as H, C, N, O, Si, P, S, Se, In, Ge, Sn, etc., and the additive may contain one or a combination of a plurality of alkali metal elements, alkaline earth metal elements, transition metal elements, and rare earth elements.

[0034] The second aspect of the embodiments of the present application provides a method for manufacturing a fluorine-containing compound solid electrolyte. This method involves subjecting AX powder and MB y powder to a solid-phase reaction by mechanical ball milling under an anhydrous and oxygen-free inert atmosphere to obtain a fluorine-containing compound solid electrolyte (AX) a MB y including obtaining

[0035] In some embodiments, the anhydrous and oxygen-free inert atmosphere is N2 or Ar gas

[0036] Furthermore, an Ar gas is used for the inert atmosphere.

[0037] In some embodiments, in the process of mechanical ball milling and pulverization, it is necessary to effectively cool the ball mill tank to prevent the temperature of the tank from being too high. Furthermore, a cycle water cooling method is adopted. [[ID=​​​​​​​​​​​​​​ In some embodiments, two types of fluorine-containing compound solid electrolytes (ABF4) a MB y In an anhydrous and oxygen-free inert atmosphere, raw material ABF4 powder and MB were mixed according to the stoichiometric ratio. y The powder is subjected to a solid-state reaction using a mechanical ball mill method to produce a halogen-boron fluoride compound solid electrolyte (ABF4). a MB y obtained.

[0040] In some embodiments, the control parameters during mechanical ball milling include: (1) The ball mill beads have a diameter of 3 mm to 10 mm. (2) The ratio of material to balls is 60:1 to 20:1; (3) The ball mill time is 1 hour to 30 hours. (4) The rotation speed of the ball mill is 400 r / min to 800 r / min.

[0041] Furthermore, the ball mill beads have a diameter of 3 mm to 10 mm, and specific examples of the ball mill beads have a diameter of 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, etc.

[0042] Furthermore, the ratio of material to balls is 60:1 to 20:1, and specific examples of the ratio of material to balls include 20:1, 25:1, 30:1, 35:1, 40:1, 45:1, 50:1, 55:1, and 60:1.

[0043] Furthermore, the ball milling time is 1 hour to 30 hours, and specific examples of the ball milling time are 1 hour, 1.5 hours, 2 hours, 3 hours, 5 hours, 6 hours, 8 hours, 10 hours, 12 hours, 14 hours, 18 hours, 20 hours, 22 hours, 24 hours, 26 hours, 28 hours, 30 hours, etc.

[0044] Furthermore, the rotation speed of the ball mill is 400 r / min to 800 r / min, and specific examples of the rotation speed of the ball mill are 400 r / min, 450 r / min, 500 r / min, 550 r / min, 600 r / min, 650 r / min, 700 r / min, 750 r / min, 800 r / min, etc.

[0045] Furthermore, the diameter of the ball mill beads is 3 mm and the material to ball ratio is 30:1.

[0046] Furthermore, the ball milling time is 6 hours, and the rotation speed of the ball mill is 500 r / min.

[0047] It should be noted that when mild ball milling conditions are used (e.g., ball mill beads of 3 mm, ball-to-material ratio of 20:1, ball milling time of 1 hour, and ball mill rotation speed of 400 r / min), the energy provided by the ball mill is insufficient to drive the reaction, resulting in a large amount of raw material remaining in the final product. When vigorous ball milling conditions are used (e.g., ball mill beads of 10 mm, ball-to-material ratio of 80:1, ball milling time of 40 hours, and ball mill rotation speed of 800 r / min), excessive ball milling precipitates thermodynamically stable impurity phases, including LiCl and LiF. Therefore, the present application has been limited to the specific parameters of the mechanical ball milling process after thorough research. Specific ball milling conditions are necessary to obtain an impurity-free electrolyte with high ionic conductivity. As a preferred solution, the ball mill conditions are set as follows: ball mill beads are 3 mm, the ball to material ratio is 60:1, and the ball mill rotation speed is 600 r / min, which can fully guarantee the production of an impurity-free electrolyte with high ionic conductivity.

[0048] In some embodiments, the mechanical ball milling process further comprises a premixing step, in which the AX powder and the MB powder are mixed in a stoichiometric ratio under an anhydrous, oxygen-free, inert atmosphere. yThe powders are premixed to obtain a premixed powder, and then the premixed powder is mechanically ball milled to form a fluorine-containing compound solid electrolyte (AX). a MB y This includes synthesizing the

[0049] Furthermore, the anhydrous and oxygen-free inert atmosphere is N2 or Ar gas, and furthermore, Ar gas is used.

[0050] Furthermore, premixing may be carried out using means such as a mortar, a hand mill, or a mixer.

[0051] A third aspect of the present invention provides a battery including the above-mentioned fluorine-containing compound solid electrolyte or the fluorine-containing compound solid electrolyte obtained by the above-mentioned production method.

[0052] In some embodiments, the battery is an all-solid-state battery.

[0053] Furthermore, the all-solid-state battery includes a positive electrode plate, a negative electrode plate, and a solid electrolyte sheet located between the positive electrode plate and the negative electrode plate, the solid electrolyte sheet being obtained by cold-pressing a solid electrolyte material, and the solid electrolyte material including the fluorine-containing compound solid electrolyte or the fluorine-containing compound solid electrolyte produced by the production method.

[0054] Furthermore, the positive electrode plate can be obtained by cold pressing or coating the positive electrode active material and the positive electrode filler.

[0055] The positive electrode active material includes, but is not limited to, at least one of cobalt aluminum oxide, lithium iron phosphate, lithium-rich phase lithium manganese oxide, lithiated layered oxide, and lithiated layered sulfide. The positive electrode filler is at least one of an ion conductor, a conductive agent, and an adhesive. The ion conductor and the solid electrolyte between the positive and negative electrodes of the battery are the same material. The conductive agent may include at least one of graphite, carbon black, acetylene black, ketjen black, and carbon fiber. The adhesive may include at least one of styrene butadiene rubber, polytetrafluoroethylene, polyvinylidene fluoride, and polyethylene. Cold pressing or coating methods are common methods for manufacturing positive electrode plates in the art.

[0056] Furthermore, the negative electrode plate can be obtained by cold pressing or coating the negative electrode active material and the negative electrode filler.

[0057] The negative electrode active material is A + This refers to a material capable of storing and releasing ions, including, but not limited to, metallic materials, graphite, silicon, etc. The metallic materials may be elemental metals or alloys. When metallic materials are used as the negative electrode active material, a negative electrode filler may not be used. The negative electrode filler is at least one of an ion conductor, a conductive agent, and an adhesive. The ion conductor and the solid electrolyte between the positive and negative electrodes of the battery are the same material. The conductive agent may include at least one of graphite, carbon black, acetylene black, ketjen black, and carbon fiber. The adhesive may include at least one of styrene butadiene rubber, polytetrafluoroethylene, polyvinylidene fluoride, and polyethylene. Cold pressing or the V method is a common method for manufacturing negative electrode plates in the art.

[0058] The following description will be given in conjunction with specific examples.

[0059] [Example 1] This example provides a perfluoro compound solid electrolyte (Li3PO4)TiF4, and the specific manufacturing method is as follows:

[0060] In an anhydrous, oxygen-free glove box under argon atmosphere, Li3PO4 and TiF4 were mixed in a 1:1 ratio of the amounts of substances and thoroughly premixed by hand grinding using an agate mortar for 10 min.

[0061] The premixed powder (approximately 1 g) was transferred to a 75 mL ball mill tank, and 40 g of 3 mm diameter grinding beads were added. The tank was then evacuated and sealed. Ball milling was performed for 6 hours in a planetary ball mill at a rotation speed of 600 r / min. After ball milling was completed, the ball mill tank was transferred to a glove box, opened, and the powder inside the tank was removed. The resulting (Li3PO4)TiF4 perfluorocompound solid electrolyte was synthesized.

[0062] [Example 2] This example provides a perfluoro compound solid electrolyte (Li3PO4)SnF4, and the specific manufacturing method is the same as that of Example 1, except that the raw material TiF4 is replaced with SnF4.

[0063] [Example 3] This example provides a perfluoro compound solid electrolyte (Li2CO3)TiF4, and the specific manufacturing method is the same as that of Example 1, except that the raw material Li3PO4 is replaced with Li2CO3.

[0064] [Example 4] This example provides a perfluorocompound solid electrolyte (LiBF4)2TiF4, and the specific preparation method is the same as that of Example 1, except that the raw material Li3PO4 is replaced with LiBF4, and the amount ratio of the corresponding raw materials is changed from 1:1 to 2:1.

[0065] [Example 5] In this example, a perfluoro compound solid electrolyte (Li3PO4)(SiF4) 0.2TiF4 is provided, and the specific manufacturing method is the same as in Example 1, with the difference being that: The raw material SiF4 was added, and the ratio of the amounts of the raw materials was changed to Li3PO4:SiF4:TiF4=1:0.2:1.

[0066] [Example 6] This embodiment provides a halogen-boron fluorine compound solid electrolyte (LiBF4)2TaCl5, and the specific manufacturing method is as follows:

[0067] In an anhydrous, oxygen-free argon atmosphere glove box, LiBF4 and TaCl5 were mixed in a ratio of 2:1 in terms of the amount of material and thoroughly premixed by hand grinding for 10 min using an agate mortar.

[0068] The premixed powder (approximately 1 g) was transferred to a 75 mL ball mill tank, and 40 g of 3 mm diameter grinding beads were added. The tank was then evacuated and sealed. Ball milling was performed for 10 hours in a planetary ball mill at a rotation speed of 600 rpm. After ball milling was completed, the ball mill tank was transferred to a glove box, opened, and the powder inside the tank was removed. The resulting (LiBF)TaCl halogen-boron fluoride compound solid electrolyte was synthesized.

[0069] [Example 7] This example provides a halogen-boron fluorine compound solid electrolyte (LiBF4)3TaCl5, and the specific manufacturing method is the same as that of Example 1, with the following differences: The ratio of the amount of raw material LiBF4 to TaCl5 was changed from 2:1 to 3:1.

[0070] [Example 8] This example provides a halogen-boron fluorine compound solid electrolyte (LiBF4) TaCl5, and the specific manufacturing method is the same as that of Example 1, except that the ratio of the amount of raw material LiBF4 and TaCl5 is changed from 2:1 to 1:1.

[0071] [Example 9] This example provides a halogen-boron fluorine compound solid electrolyte (LiBF4)2ZrCl4, and the specific manufacturing method is the same as that of Example 1, except that the raw material TaCl5 is replaced with ZrCl4 and the ball milling time is changed from 10 hours to 20 hours.

[0072] [Example 10] In this example, a halogen-boron fluorine compound solid electrolyte (Li2O) 0.2 (LiBF4)2TaCl5 is provided, and the specific preparation method is the same as in Example 1, except that an additive Li2O is added to the raw materials, and the amount ratio of the raw materials is Li2O:LiBF4:TaCl5=0.2:2:1.

[0073] [Example 11] This example provides an all-solid-state lithium battery, which uses a perfluorocompound solid electrolyte (L i3 PO4)TiF4, and the specific assembly process is as follows:

[0074] Step 1: Commercially available lithium-rich cathode Li 1.14 Ni 0.29 Mn 0.57 O2 (used as a positive electrode active material), (Li3PO4)TiF4 (used as an ionic conductor), and VGCF (vapor-deposited carbon fiber, used as an electronic conductor) were weighed in a mass ratio of 65:30:5 and manually ground in a mortar for 10 minutes until uniformly mixed to form a composite positive electrode.

[0075] Step 2: 50 mg of the perfluorocompound solid electrolyte (Li3PO4)TiF4 powder synthesized in Example 1 was weighed out and cold-pressed into a solid electrolyte sheet with a diameter of 10 mm at a pressure of 100 MPa and held for 2 minutes. 50 mg of Li6PS5Cl was weighed out to form a barrier layer for the perfluorocompound solid electrolyte (Li3PO4)TiF4 and LiIn negative electrode. This was evenly dispersed on one surface of the (Li3PO4)TiF4 solid electrolyte sheet and cold-pressed at a pressure of 100 MPa and held for 2 minutes.

[0076] Step 3: 10 mg of the composite positive electrode prepared in Step 1 was weighed and evenly spread on the other surface of the (LiPO)TiF solid electrolyte sheet prepared in Step 2, followed by cold pressing at a pressure of 350 MPa and maintaining the pressure for 2 minutes.

[0077] Step 4: A commercially available indium sheet (10 mm in diameter, 200 μm in thickness) was used as the negative electrode active material and attached to the other surface of the Li6PS5Cl barrier layer produced in Step 2, forming a four-layer structure of "positive electrode plate - solid electrolyte sheet - barrier layer - negative electrode plate." A pressure of 100 MPa was applied to the entire structure, completing the assembly and obtaining an all-solid-state lithium battery.

[0078] The above steps 1 to 4 were all carried out in a glove box with an anhydrous and oxygen-free argon atmosphere.

[0079] [Example 12] This example provides an all-solid-state lithium battery, which is obtained by assembling using the halogen-boron fluorine compound solid electrolyte (LiBF4)2TaCl5 according to Example 1, and the specific assembly process is as follows:

[0080] Step 1: Commercially available lithium-rich cathode Li 1.14 Ni 0.29 Mn 0.57 O2 (used as a positive electrode active material), (LiBF4)2TaCl5 (used as an ionic conductor), and VGCF (vapor-deposited carbon fiber, used as an electronic conductor) were weighed in a mass ratio of 65:30:5 and manually ground in a mortar for 10 minutes until uniformly mixed to form a composite positive electrode.

[0081] Step 2: 50 mg of the halogen-boron fluorine compound solid electrolyte (LiBF)TaCl powder synthesized in Example 1 was weighed out and cold-pressed into a solid electrolyte sheet with a diameter of 10 mm at a pressure of 100 MPa and held for 2 minutes. 50 mg of LiPSCl was weighed out as a barrier layer between the halogen-boron fluorine compound solid electrolyte (LiBF)TaCl and the LiIn negative electrode, and uniformly dispersed on one surface of the (LiBF)TaCl solid electrolyte sheet. The sheet was then cold-pressed at a pressure of 100 MPa and held for 2 minutes.

[0082] Step 3: 10 mg of the composite positive electrode prepared in Step 1 was weighed and evenly spread on the other surface of the (LiBF)TaCl solid electrolyte sheet prepared in Step 2, followed by cold pressing at a pressure of 350 MPa and maintaining the pressure for 2 minutes.

[0083] Step 4: A commercially available indium sheet (10 mm in diameter, 200 μm in thickness) was used as the negative electrode active material and attached to the other surface of the Li6PS5Cl barrier layer produced in Step 2, forming a four-layer structure of "positive electrode plate - solid electrolyte sheet - barrier layer - negative electrode plate." A pressure of 100 MPa was applied to the entire structure, completing the assembly and obtaining an all-solid-state lithium battery.

[0084] The above steps 1 to 4 were all carried out in a glove box with an anhydrous and oxygen-free argon atmosphere.

[0085] [Example 13] This example provides an all-solid-state LiIn-LiCoO2 battery, and the specific assembly process is the same as that of Example 12, except that the positive electrode active material is Li 1.14 Ni 0.29 Mn 0.57 The conductive agent was changed from VGCF to carbon black, and the mass ratio of the corresponding raw materials was changed from 65:30:5 to 70:30:1.

[0086] [Comparative Example 1] This case provides a solid electrolyte, and the specific manufacturing method is as follows:

[0087] In an anhydrous, oxygen-free glove box under argon atmosphere, LiF and TaF5 were mixed in a 1:1 ratio of the amounts of materials and thoroughly mixed by hand grinding using an agate mortar for 10 min.

[0088] The mixed powder (approximately 1 g) was transferred to a 75 mL ball mill tank, and 40 g of 3 mm diameter grinding beads were added. The tank was then evacuated and sealed. Ball milling was performed for 20 hours in a planetary ball mill at a rotation speed of 600 rpm. After ball milling was completed, the ball mill tank was transferred to a glove box, opened, and the powder inside the tank was removed. This resulted in the synthesis of a LiTaF6 halide solid electrolyte.

[0089] Comparative Example 2 This case provides a solid electrolyte, and the specific manufacturing method is as follows:

[0090] In an anhydrous, oxygen-free argon atmosphere glove box, LiF and ZrCl4 were mixed in a ratio of 8:1 by material volume and thoroughly premixed by hand grinding for 10 min using an agate mortar.

[0091] The premixed powder (approximately 1 g) was transferred to a 75 mL ball mill tank, and 40 g of 3 mm diameter grinding beads were added. The tank was then evacuated and sealed. Ball milling was performed for 20 hours in a planetary ball mill at a rotation speed of 600 rpm. After ball milling was completed, the ball mill tank was transferred to a glove box, opened, and the powder inside the tank was removed. This resulted in the synthesis of a Li8F8ZrCl4 halide solid electrolyte.

[0092] Comparative Example 3 This case provides a solid electrolyte, and the specific manufacturing method is as follows:

[0093] In an anhydrous, oxygen-free argon atmosphere glove box, LiCl and ZrCl4 were mixed in a ratio of 2:1 by material volume and thoroughly premixed by hand grinding using an agate mortar for 10 min.

[0094] The premixed powder (approximately 1 g) was transferred to a 75 mL ball mill tank, and 40 g of 3 mm diameter grinding beads were added. The tank was then evacuated and sealed. Ball milling was performed for 20 hours in a planetary ball mill at a rotation speed of 600 rpm. After ball milling was completed, the ball mill tank was transferred to a glove box, opened, and the powder inside the tank was removed. This resulted in the synthesis of a Li2ZrCl6 halide solid electrolyte.

[0095] I. Characterization analysis 1. Ionic Conductivity Characterization Analysis (1) Characterization method In a glove box with an anhydrous and oxygen-free argon atmosphere, the solid electrolyte powders prepared in Examples 1 to 4, Examples 6 to 10, and Comparative Examples 1 and 2 were filled into a cylindrical tableting die (diameter 10 mm) and cold-pressed at a pressure of 375 MPa for 2 minutes to obtain solid electrolyte sheets with a thickness of 0.5 mm to 1.5 mm and a diameter of 10 mm. The upper and lower surfaces of the solid electrolyte sheet were gold-plated, and the upper and lower surfaces were sandwiched between two stainless steel blocking electrodes and connected to an electrochemical workstation. Electrochemical AC impedance spectroscopy was performed at room temperature, and the measured electrochemical impedance spectroscopy revealed that the room temperature Li + Ionic conductivity was extracted.

[0096] (2) Characterization results Table 1 shows the ionic conductivity of each solid electrolyte sample at 60°C.

[0097] FIG. 1 shows the electrochemical impedance spectrum of (Li3PO4)TiF4 synthesized in Example 1 at 60°C. [Table 1] JPEG2026021290000002.jpg170170

[0098] 2. Crystal Structure Characterization Analysis (1) Characterization method The solid electrolytes produced in Examples 6 to 8 were characterized using an X-ray diffractometer.

[0099] (2) Characterization results As shown in Figure 2, the crystal structures of the (LiBF4)2TaCl5, (LiBF4)3TaCl5, (LiBF4)TaCl5 and (Li3PO4)TiF4 solid electrolytes synthesized in the examples are characterized, respectively.

[0100] As can be seen from the results, the diffraction peaks of the three types of halogen-boron fluorine compound solid electrolytes according to the examples can be identified as the residual raw material phase LiBF4, with characteristic XRD peaks located at 2 theta = 14.1°, 20.0°, 24.9°, 26.4°, and 31.8°. It was shown that the above three types of halogen-boron fluorine compound solid electrolytes contain a large amount of amorphous phase in addition to the raw material crystalline phase, and that the amorphous phase contains several elements, including Li, B, F, Ta, and Cl.

[0101] As shown in FIG. 3, the XRD pattern of (Li3PO4)TiF4 does not show any characteristic diffraction peaks, and the (Li3PO4)TiF4 solid electrolyte is in an amorphous phase.

[0102] 3. Electrochemical Window Test (1) Test method Linear scan tests were performed at room temperature on a battery constructed with solid electrolyte + carbon black (5:5 mass ratio) solid electrolyte|Li6PS5Cl|Li using an EC-lab electrochemical workstation.

[0103] (2) Test results 4 and 5, the test results show that (LiBF4)2TaCl5 does not exhibit a significant oxidation peak even at 6 V or higher, and (Li3PO4)TiF4 does not exhibit a significant oxidation peak even at 6 V or higher.

[0104] 4. Constant current charge / discharge test (1) Test method At room temperature, a constant current charge / discharge test was performed on the all-solid-state batteries according to Examples 9 and 10 using a blue battery test system, and the voltage range was 2.5 V to 4.8 V (Li + / voltage relative to Li) and the cycle rate is 0.3C.

[0105] (2) Test results The test results are shown in Figures 6 and 7.

[0106] The all-solid-state battery according to Example 9 has a reversible capacity of 177.2 mAh g at a rate of 0.3 C. -1 The efficiency of the first cycle and the efficiency of the second cycle are 87.0% and 99.3%, respectively.

[0107] The all-solid-state battery according to Example 10 has a reversible capacity of 203.1 mAh g at a rate of 0.3 C. -1 The efficiency of the first and second cycles is 91.5% and 99.2%, respectively.

[0108] The above description is only a preferred embodiment of the present application, and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principle of the present application should fall within the protection scope of the present application.

Claims

1. A fluorine-containing compound solid electrolyte having a general structural formula (AX): ａ MB ｙ wherein A is at least one of Li, Na, K, Ag, and Cu, M is at least one of Ti, Sn, Ta, Nb, Zr, Hf, Ga, Al, and Fe, and 0.5<a<4; and B is F, X is at least one of an oxygen-containing anion and a fluorine-containing anion, and y is 4 or 5; Or, B is at least one of F, Cl, Br, and I, and X is BF ４ and y is 3, 4, or 5.

2. A is Li; M is at least one of Zr, Hf, Ta, Nb, Al, Fe, and Ga; B is at least one of F, Cl, Br, and I; X is BF ４ and 2. The fluorine-containing compound solid electrolyte according to claim 1, wherein y is 3 or 4.

3. A is at least one of Li, Na, K, Ag, and Cu; M is at least one of Ti, Sn, Ta, Nb, Zr, Hf, and Ga; B is F, and X is at least one of an oxygen-containing anion and a fluorine-containing anion; 2. The fluorine-containing compound solid electrolyte according to claim 1, wherein y is 4 or 5.

4. The source of the oxygen-containing anion is O, O ２ , CO ３ , P.O. ４ , S.O. ４ , SiO ３ , NO ３ , MoO ３ , W.O. ３ , B ４ O ７ and P ２ O ７ and / or the source of fluorine-containing anions comprises at least one of BF ４ , P.F. ６ and AsF ６ 2. The fluorine-containing compound solid electrolyte according to claim 1, comprising at least one of:

5. In the fluorine-containing compound solid electrolyte, X and (AX) ａ MB ｙ MB in ｙ and a transition metal-halogen ion polyhedron consisting of the above-mentioned compound (A) and (B) are connected to form an open frame structure, and A ions are filled in pores of the open frame structure.

6. 2. The fluorine-containing compound solid electrolyte according to claim 1, further comprising an auxiliary additive, wherein the mass of the auxiliary additive satisfies 0<w%≦20%.

7. A method for producing a fluorine-containing compound solid electrolyte, comprising: AX powder and MB powder were mixed in a stoichiometric ratio under an anhydrous and oxygen-free inert atmosphere. ｙ The powder is subjected to a solid-phase reaction by a mechanical ball mill method to obtain a fluorine-containing compound solid electrolyte (AX). ａ MB ｙ 1. A method for producing a fluorine-containing compound solid electrolyte, comprising:

8. In the mechanical ball milling process, the control parameters are: (1) The ball mill beads have a diameter of 3 mm to 10 mm; (2) The ratio of material to ball is 60:1 to 20:1; (3) The ball mill time is 1 hour to 30 hours; (4) The method for producing a fluorine-containing compound solid electrolyte according to claim 7, wherein the rotation speed of the ball mill is 400 r / min to 800 r / min.

9. The method further includes a premixing process before the mechanical ball milling process, and the premixing process includes:

8. The method for producing a fluorine-containing compound solid electrolyte according to claim 7, comprising premixing an AX powder and an MBy powder in accordance with a stoichiometric ratio in an anhydrous and oxygen-free inert atmosphere to obtain a premixed powder.

10. A battery comprising the fluorine-containing compound solid electrolyte according to claim 1.

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