Solid-state electrolyte and preparation method and application thereof

Abstract

The application discloses a kind of solid electrolyte and preparation method and application thereof, it is related to solid battery technical field.The chemical general formula of the solid electrolyte is Li 1‑x Al x TaO 2x Cl 6‑2x Wherein, 0≤x<1, include Al-O-Al network structure.Preparation method includes that lithium salt, tantalum salt, aluminium chloride and antimony oxide are mixed after ball milling and are carried out vacuum heat treatment.The electrolyte has viscoelasticity, can be realized with electrode in low pressure condition Close contact, low pressure ion conductivity is greater than or equal to 1 mS / cm.

Description

Technical Field

[0001] This invention relates to the field of battery technology, specifically to a solid electrolyte, its preparation method, and its application. Background Technology

[0002] Solid-state batteries offer significant advantages in addressing thermal runaway safety hazards and achieving high energy density by using non-flammable inorganic solid electrolytes instead of organic liquid electrolytes. However, conventional inorganic electrolyte materials in existing technologies, such as oxide electrolytes, typically have a high rigidity modulus. This rigidity makes it difficult to form a tight and durable physical contact between the electrolyte and electrode materials, especially during battery cycling when the electrode materials undergo volume changes, leading to deterioration of the interfacial contact and persistently high interfacial impedance.

[0003] To maintain effective ion transport channels, existing technologies typically require continuously applying high external stacking pressures to the battery system, ranging from several megapascals to tens of megapascals. This high-pressure dependence not only significantly increases the complexity and manufacturing cost of the battery packaging system but also threatens the mechanical stability of the battery during long-term cycling, limiting the large-scale application of solid-state batteries.

[0004] Therefore, developing a novel solid electrolyte system that combines structural stability with appropriate deformation capability has become an urgent technical problem to be solved in this field. Summary of the Invention

[0005] This invention provides a solid electrolyte, its preparation method, and its application, to solve the problems of high rigidity, poor interfacial contact, and the need for high stacking pressure in related technologies.

[0006] The applicant discovered that by constructing a specific Al-O-Al network structure, solid electrolytes can acquire viscoelastic properties, thereby improving interfacial contact.

[0007] Based on the above findings, this application provides the following technical solution: In a first aspect, the present invention provides a solid electrolyte, the solid electrolyte having the general chemical formula Li. 1- x Al x TaO 2x Cl 6-2x Where 0≤x<1, the solid electrolyte contains an Al-O-Al network structure.

[0008] In some embodiments, the raw materials for preparing the solid electrolyte include lithium salt, tantalum salt, aluminum chloride, and antimony oxide.

[0009] In some embodiments, the molar ratio of the lithium salt to the tantalum salt is (0.5~2):1, preferably (0.8~1.2):1.

[0010] In some embodiments, the lithium salt includes at least one of lithium hydroxide and lithium chloride.

[0011] In some embodiments, the tantalum salt includes tantalum chloride.

[0012] In some embodiments, the molar ratio of aluminum chloride to antimony oxide is (0.5~1.5):1, preferably (0.8~1.2):1.

[0013] In some embodiments, the total mass of the lithium salt and the tantalum salt is A, and the total mass of the aluminum chloride and the antimony oxide is B, wherein A:B = 1:(0.05-0.12), preferably 1:(0.05~0.08).

[0014] Secondly, the present invention provides a method for preparing the aforementioned solid electrolyte, comprising the following steps: The precursor was obtained by ball milling a mixture of lithium salt, tantalum salt, aluminum chloride, and antimony oxide. The precursor is heat-treated under vacuum conditions to obtain the solid electrolyte.

[0015] In some embodiments, the ball milling time is 10-40 hours.

[0016] In some embodiments, the heat treatment temperature is 200-400°C.

[0017] Thirdly, the present invention provides a solid-state battery, including a positive electrode, a negative electrode, and an electrolyte layer located between the positive electrode and the negative electrode, wherein the electrolyte layer contains the solid electrolyte.

[0018] In some embodiments, the solid-state battery operates normally under a stacking pressure of less than 0.1 MPa.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The solid electrolyte provided in this application has excellent ionic conductivity performance. Under low pressure conditions, the ionic conductivity is ≥1 mS / cm, and after applying a certain pressure, the ionic conductivity can be increased to 9 mS / cm, which can meet the usage requirements of high-rate batteries.

[0020] 2. This application introduces Al elements to construct a LiTaAlOCl structure containing an Al-O-Al network, enabling the electrolyte to exhibit a glassy state and viscoelasticity. Compared to the crystalline structures commonly found in existing technologies, the glassy structure of this application has lower requirements for stacking pressure, can adapt to volume changes at the electrode interface, and maintains good interfacial contact under low-pressure conditions. Simultaneously, chlorine atoms, as terminal groups, synergistically work with the Al-O-Al network to induce a low-coordination, distorted environment conducive to lithium-ion transport, lowering the lithium-ion migration barrier and further improving ionic conductivity.

[0021] 3. This application introduces antimony oxide into the preparation process to broaden the lithium-ion transport channel using oxygen. Furthermore, the antimony chloride generated in the reaction volatilizes in gaseous form, which is beneficial for the forward reaction and product purification. The introduction of Sb also helps to broaden the lithium-ion transport channel and synergistically improves ionic conductivity. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 The image shows the AC impedance spectrum of the solid electrolyte prepared in Example 1. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0025] Solid-state batteries are hailed as the ultimate solution for next-generation power batteries. Their core advantage lies in using non-flammable inorganic solid electrolytes instead of current organic liquid electrolytes, fundamentally solving safety hazards such as thermal runaway and making it possible to match lithium metal anodes and break through the 500Wh / kg energy density limit. However, this technology faces technical challenges in its industrialization process due to the solid-solid interface. Traditional oxide-based inorganic electrolytes are rigid, making it difficult to form a tight and lasting physical contact with electrode materials, resulting in high interfacial impedance. To maintain effective ion transport channels, the battery system needs to continuously apply stacking pressures of several megapascals to tens of megapascals, which not only increases the complexity of the system structure and manufacturing cost but also adversely affects the mechanical stability of the battery during long-term cycling.

[0026] Given the aforementioned technological bottlenecks, developing novel electrolyte systems with both rigidity and flexibility is of significant research importance. Viscoelastic glass-inorganic electrolytes (VIGLAS) can specifically address the shortcomings of existing technologies, and their necessity lies primarily in the following aspects: This material possesses unique viscoelasticity, exhibits structural stability and deformation capability at room temperature, and can adapt to changes in electrode volume and surface undulations, achieving low-resistance interfacial contact under near-zero external pressure conditions; simultaneously, it possesses low melting point characteristics, combining the excellent interfacial wetting ability of liquid batteries with the intrinsic safety of solid-state batteries. It can fill electrode pores through low-temperature melting, forming a stable solid interface upon cooling, thus optimizing the fabrication process; furthermore, its excellent deformability and film-forming ability can meet the demands of high-throughput, low-cost large-scale production. Therefore, developing VIGLAS electrolytes represents a key technological innovation in the field of solid-state batteries and is of great significance in promoting the transition of solid-state batteries from laboratory research to commercial mass production.

[0027] However, existing similar oxyhalide electrolytes still have significant drawbacks, as follows: Prior art 1 discloses a low-melting-point electrolyte material, the synthesis method of which is as follows: LiCl and AlCl3 are mixed in stoichiometric ratio and sintered at 200°C for 5 hours. The resulting mixture is then mixed with Sb2O3 and sintered at 250°C for 1 hour to finally obtain LiAlCl2.5O0. 75 This method prepares a low-melting-point electrolyte by adding Al and replacing chlorine with oxygen in tetrachloroaluminate, giving the material good ionic conductivity and chemimechanical compatibility, enabling use under low-pressure conditions (<0.1 MPa) and an ionic conductivity of 1 mS / cm. However, this material is prepared using a two-step sintering method, resulting in a complex experimental process; and the raw material LiCl is highly hygroscopic, imposing stringent requirements on the preparation and usage environment. Furthermore, the material's room-temperature ionic conductivity is relatively low, and its electrical conductivity needs further improvement.

[0028] Existing technology 2 synthesizes LiTaOCl4 electrolyte using a solid-state method, employing LiOH and TaCl5 as raw materials, and preparing the finished product through ball milling for 40 hours. This material exhibits an ionic conductivity of 12.4 mS / cm under a molding pressure of 300 MPa. However, this material is mechanically soft, requiring an ultra-high molding pressure of 300 MPa to eliminate interfacial contact resistance. This ultra-high pressure increases the difficulty of application, imposes stringent requirements on production and processing conditions, and is not conducive to practical industrial application.

[0029] In view of this, the present invention provides a solid electrolyte, its preparation method and application, to solve the problems of high rigidity, poor interfacial contact and high stacking pressure required in related technologies.

[0030] In a first aspect, the present invention provides a solid electrolyte, wherein, according to an embodiment of the present invention, the solid electrolyte has the general chemical formula Li. 1-x Al x TaO 2x Cl 6-2x Wherein, 0≤x<1, preferably 0.05≤x≤0.3, and the solid electrolyte contains an Al-O-Al network structure.

[0031] This invention utilizes the specific chemical formula Li 1-x Al x TaO 2x Cl 6-2x The structure employs an Al-O-Al network, utilizing oxygen bridges to break down the original crystal structure and form a glassy network. Chlorine atoms, acting as terminal groups, synergistically work with the Al-O-Al network to induce a low-coordination, distorted environment conducive to lithium-ion transport, reducing the ion migration energy barrier and thus improving the ionic conductivity of the solid-state electrolyte. Furthermore, this structure exhibits a low glass transition temperature, endowing the solid-state electrolyte with viscoelasticity similar to organic polymers. This allows for excellent mechanical matching with the electrode interface without additional lamination, thereby solving the problems of poor interfacial contact and high-voltage dependence caused by the high rigidity of traditional inorganic electrolytes.

[0032] It should be noted that the term "viscoelasticity" refers to a material that possesses both viscous and elastic properties, allowing it to deform under external forces and partially recover, thus helping to alleviate interfacial stress.

[0033] The term "Al-O-Al network structure" refers to a network framework formed by aluminum-oxygen bonds, which can be characterized by solid-state nuclear magnetic resonance (NMR) or Fourier transform infrared spectroscopy (FTIR).

[0034] In some embodiments of the present invention, the raw materials for preparing the solid electrolyte include lithium salt, tantalum salt, aluminum chloride (AlCl3), and antimony oxide (Sb2O3). Using lithium salt, tantalum salt, aluminum chloride, and antimony oxide as raw materials, a Li-O-Al network structure can be constructed through a solid-state reaction. 1-x Al x TaO 2x Cl 6-2x The system utilizes alumina, which not only provides oxygen to construct the Al-O-Al network, promoting the formation of a glassy, ​​amorphous electrolyte and imparting viscoelasticity to the solid electrolyte, allowing it to adhere tightly to the electrode interface even under low pressure, but also, during subsequent heat treatment, the antimony chloride generated from the reaction of antimony and chlorine volatilizes in gaseous form, driving the reaction equilibrium to the forward direction, which is beneficial for improving product purity and reducing grain boundary impedance. Furthermore, the introduction of oxygen can broaden lithium-ion transport channels, inducing the formation of a low-coordination distortion environment conducive to ion migration, thereby improving the ionic conductivity of the solid electrolyte.

[0035] In some embodiments of the present invention, the molar ratio of the lithium salt to the tantalum salt is (0.5-2):1. Controlling this molar ratio within the above range can enhance lattice stability and suppress structural collapse during charging and discharging by utilizing the high bond energy of the Ta-O bond; it can also optimize lithium-ion migration channels and improve ion conduction performance through lithium vacancies and local lattice distortion induced by tantalum. More preferably, the molar ratio of the lithium salt to the tantalum salt is (0.8-1.2):1.

[0036] This application does not impose any particular limitation on the types of lithium salt and tantalum salt, and those skilled in the art can select them according to actual process requirements. For example, the lithium salt is selected from at least one of lithium hydroxide (LiOH) and lithium chloride (LiCl); the tantalum salt is selected from tantalum chloride (TaCl5).

[0037] In some embodiments of the present invention, the molar ratio of aluminum chloride to antimony oxide is (0.5-1.5):1. Limiting the molar ratio of aluminum chloride to antimony oxide to this range allows the introduction of antimony oxide to replace chlorine with oxygen, resulting in a larger migration space for lithium ions and improving ionic conductivity. Simultaneously, aluminum chloride can construct a stable Al-O-Al network framework, promoting the formation of a glassy amorphous electrolyte structure. Further, the molar ratio of aluminum chloride to antimony oxide is preferably (0.8-1.2):1.

[0038] In some embodiments of the present invention, the total mass of the lithium salt and the tantalum salt is A, and the total mass of the aluminum chloride and the antimony oxide is B, wherein A:B = 1:(0.05-0.12). By limiting the above parameter range, based on the stable lattice constructed by the lithium salt and tantalum salt, the appropriate combination of aluminum chloride and antimony oxide can both utilize the antimony oxide to replace the chlorine element in the system, thus widening the lithium-ion migration channels; and utilize the aluminum chloride to construct an Al-O-Al network framework, maintaining the glassy structure of the electrolyte. Further, A:B is preferably 1:(0.05-0.08).

[0039] Secondly, this application provides a method for preparing the solid electrolyte, which, according to an embodiment of this application, includes the following steps: S100: Lithium salt, tantalum salt, aluminum chloride and antimony oxide are mixed and then ball-milled to obtain the precursor.

[0040] This step involves ball milling to achieve a uniform mixture of lithium salt, tantalum salt, aluminum chloride, and antimony oxide, forming a uniformly pressurized powder. This increases the reaction contact area and introduces mechanical energy to activate the reaction, enabling the construction of an Al-O-Al network structure during subsequent heat treatment. The thorough dispersion of antimony oxide in the matrix provides an oxygen source and drives reaction equilibrium through the volatilization of antimony chloride, preventing localized component segregation. Furthermore, the introduction of Sb into the reaction system helps to broaden the lithium-ion transport channels.

[0041] In some embodiments of the present invention, the ball milling time is 10-40 hours. Limiting the ball milling time to the above range ensures thorough mixing of the raw materials, enabling partial or direct initiation or acceleration of chemical reactions between solids at room temperature, and preventing the volatilization of chlorine at high temperatures.

[0042] S200. The precursor is heat-treated under vacuum conditions to obtain the solid electrolyte.

[0043] This heat treatment step, performed under vacuum conditions, facilitates the timely escape of the generated antimony chloride gas, driving the reaction equilibrium to the forward direction, improving product purity, and reducing grain boundary resistance. Furthermore, the vacuum environment effectively isolates moisture and oxygen, preventing hydrolysis or oxidation of the halide raw materials and products.

[0044] In some embodiments of the present invention, the temperature of the heat treatment is 200-400°C.

[0045] Thirdly, the present invention provides a solid-state battery. According to an embodiment of this application, the solid-state battery includes a positive electrode, a negative electrode, and an electrolyte layer located between the positive electrode and the negative electrode, wherein the electrolyte layer contains the solid electrolyte.

[0046] This solid-state battery employs a solid electrolyte with an Al-O-Al network structure, utilizing its glassy state characteristics and deformation capability to achieve a tight bond between the electrolyte layer and the positive and negative electrode interfaces. This allows the battery to maintain low interfacial impedance and stable ion transport channels even under extremely low stacking pressure (<0.1MPa), with a low-pressure ion conductivity ≥1mS / cm, which can be increased to 9mS / cm after applying pressure.

[0047] The technical solution provided by the present invention will be described in detail below with reference to the embodiments.

[0048] Unless otherwise specified, the raw materials used in the examples and comparative examples are commercially available analytical grade materials.

[0049] Example 1 Example 1 of this application provides a solid electrolyte and a solid battery, the specific preparation method of which is as follows: (1) Preparation of solid electrolytes: 1) Raw material weighing: Under glove box conditions with H2O ≤ 0.1 ppm and O2 ≤ 0.1 ppm, weigh lithium hydroxide (LiOH) and tantalum chloride (TaCl5), controlling the molar ratio of LiOH to TaCl5 to be 1:1; weigh aluminum chloride (AlCl3) and antimony oxide (Sb2O3), controlling the molar ratio of AlCl3 to Sb2O3 to be 1:1. Mix LiOH and TaCl5 and label it as component A, and mix AlCl3 and Sb2O3 and label it as component B, controlling the mass ratio of component A to component B to be 1:0.07. 2) Ball milling: The above-mentioned mixed raw materials were placed in a ball mill jar containing zirconia grinding balls, sealed, and then placed in a ball mill. Under argon protection, the mixture was ball milled at 400 rpm for 20 h to obtain a uniformly mixed precursor powder.

[0050] 3) Heat treatment: The ball-milled precursor powder is placed in a quartz crucible and then placed in a vacuum tube furnace. The furnace is evacuated to a vacuum level ≤10. -3 Pa was heated to 300℃ at a heating rate of 2℃ / min, held at that temperature for 10 h, and then naturally cooled to room temperature to obtain a solid electrolyte.

[0051] (2) Preparation of mold battery: Weigh 100mg of the prepared solid electrolyte powder and spread it evenly inside the mold cavity of the mold battery; apply a constant pressure of 300MPa to the electrolyte powder using a tablet press and hold the pressure for 1min to make the electrolyte powder densely formed and obtain a uniformly structured electrolyte sheet; after the pressure is applied, tighten the mold screws to fix the formed structure and complete the assembly of the mold battery for subsequent electrochemical performance testing.

[0052] (3) Preparation of button cell: Place the negative electrode shell of the button cell flat on a dry and insulated workbench and place the lithium metal sheet in the center of the negative electrode shell; stack the electrolyte sheet and the lithium metal sheet on the other side in sequence to form a symmetrical battery structure of lithium metal-electrolyte-lithium metal; after assembly, use a low pressure of ≤0.1MPa to seal the battery to reduce the impact of assembly pressure on the internal structure of the electrolyte; after the sealed button cell has been stabilized, place it in an electrochemical workstation to complete various electrochemical performance tests.

[0053] Example 2 (1) Preparation of solid electrolytes 1) Raw material weighing: In an argon atmosphere glove box with H2O≤0.1 ppm and O2≤0.1 ppm, weigh lithium chloride (LiCl) and tantalum chloride (TaCl5), controlling the molar ratio of LiCl to TaCl5 to be 1:1; weigh aluminum chloride (AlCl3) and antimony oxide (Sb2O3), each with a substance amount of 0.1 mol.

[0054] 2) Mixing and ball milling: First, mix LiCl and TaCl5 evenly, then add AlCl3 and Sb2O3. The mixture of LiCl and TaCl5 is designated as component A, and the mixture of AlCl3 and Sb2O3 is designated as component B. The mass ratio of component A to component B is controlled at 1:0.07. Place the mixed raw materials into a ball mill jar containing zirconia grinding balls, seal it, and place it in a vacuum mixing device (or ball mill). Mechanically mix under vacuum at 500 rpm for 10 hours to obtain the precursor powder.

[0055] 3) Heat treatment: The precursor powder is loaded into a quartz tube and evacuated to a vacuum degree ≤10. - ³ Pa. The temperature was increased to 280℃ at a rate of 2℃ / min and sintered at that temperature for 5 h. After natural cooling to room temperature, solid electrolyte powder was obtained.

[0056] (2) Preparation of mold battery: Same as in Example 1.

[0057] (3) Preparation of button cells: Same as in Example 1.

[0058] Comparative Example 1 The preparation method of this comparative example is the same as that of Example 1, except that antimony oxide is not added, only aluminum chloride is used to provide the aluminum source, and the oxygen source is insufficient.

[0059] Comparative Example 2 The preparation method of this comparative example is the same as that of Example 1, except that aluminum chloride is not added and there is no Al-O-Al network structure.

[0060] Performance testing Electrochemical performance tests were conducted on the batteries of Examples 1-2 and Comparative Examples 1-2. The test process included: 1. Ionic conductivity of the mold battery: First, the lithium metal sheet is planarized using a pressing mold, and then the electrolyte powder is pressed into a dense electrolyte sheet. The electrolyte sheet is then assembled with two lithium metal sheets to form a lithium / electrolyte / lithium symmetrical mold battery. The assembled mold battery is placed in a constant temperature environment of 25℃, and AC impedance testing is performed using an electrochemical workstation. The test frequency range is 1 MHz to 100 MHz, and the perturbation voltage is 10 mV. Impedance (Nyquist) spectra are collected and obtained. The bulk resistance R of the electrolyte is obtained by fitting the spectrum through an equivalent circuit. According to the formula σ = L / (S R) Calculate the ionic conductivity of the solid electrolyte, where L is the thickness of the electrolyte sheet and S is the effective contact area of ​​the electrolyte sheet.

[0061] 2. Ionic conductivity of coin cells: After the packaged lithium / electrolyte / lithium symmetrical coin cells were allowed to stand for adaptation, they were placed on a 25℃ constant temperature test platform; electrochemical testing was performed using the AC impedance method, with a fixed test frequency range of 1MHz-100MHz and a perturbation voltage of 10mV; the electrolyte impedance parameters were obtained by fitting the Nyquist spectrum, and the electrolyte bulk resistance value R was obtained by fitting the spectrum through an equivalent circuit; according to the formula σ = L / (S R) Calculate the ionic conductivity of the solid electrolyte, where L is the thickness of the electrolyte sheet and S is the effective contact area of ​​the electrolyte sheet.

[0062] The test results are shown in Table 1: Table 1 Performance Test Results

[0063] As can be seen from Table 1, compared with Comparative Examples 1 and 2, the solid electrolyte provided in this application has excellent ionic conductivity performance. Under low pressure conditions, the ionic conductivity is ≥1 mS / cm, and after applying a certain pressure, the ionic conductivity can be increased to 9 mS / cm, which can meet the usage requirements of high-rate batteries.

[0064] like Figure 1 As shown in the figure, the AC impedance spectrum exhibits typical electrolyte impedance behavior. The intersection point with the real axis in the high-frequency region corresponds to the bulk resistance of the electrolyte. By calculating the resistance at this point, the ionic conductivity of the material can be directly obtained.

[0065] In the description of this specification, the references to terms such as "one embodiment / mode," "some embodiments / modes," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment / mode or example is included in at least one embodiment / mode or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment / mode or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments / modes or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments / modes or examples described in this specification, as well as the features of different embodiments / modes or examples.

[0066] It should be noted that in this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, technology, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, technology, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, technology, article, or apparatus that includes said element. In this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise expressly specified.

[0067] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features of the invention herein.

Claims

1. A solid electrolyte, characterized in that, The general chemical formula of the solid electrolyte is Li 1-x Al x TaO 2x Cl 6-2x Where 0≤x<1, the solid electrolyte contains an Al-O-Al network structure.

2. The solid electrolyte as described in claim 1, characterized in that, The raw materials for preparing the solid electrolyte include lithium salt, tantalum salt, aluminum chloride, and antimony oxide.

3. The solid electrolyte as described in claim 2, characterized in that, The molar ratio of the lithium salt to the tantalum salt is (0.5-2):1, preferably (0.8-1.2):1; and / or, The lithium salt includes at least one of lithium hydroxide and lithium chloride; and / or, The tantalum salt includes tantalum chloride.

4. The solid electrolyte as described in claim 2, characterized in that, The molar ratio of aluminum chloride to antimony oxide is (0.5-1.5):1, preferably (0.8-1.2):

1.

5. The solid electrolyte as described in claim 2, characterized in that, The total mass of the lithium salt and the tantalum salt is A, and the total mass of the aluminum chloride and the antimony oxide is B, wherein A:B = 1:(0.05-0.12), preferably 1:(0.05-0.08).

6. A method for preparing a solid electrolyte as described in any one of claims 1-5, characterized in that, Includes the following steps: The precursor was obtained by ball milling a mixture of lithium salt, tantalum salt, aluminum chloride, and antimony oxide. The precursor is heat-treated under vacuum conditions to obtain the solid electrolyte.

7. The preparation method according to claim 6, characterized in that, The ball milling time is 10-40 hours.

8. The preparation method according to claim 6, characterized in that, The heat treatment temperature is 200-400℃.

9. A solid-state battery, characterized in that, It includes a positive electrode, a negative electrode, and an electrolyte layer located between the positive electrode and the negative electrode, the electrolyte layer comprising a solid electrolyte as described in any one of claims 1-5.

10. The solid-state battery as described in claim 9, characterized in that, The solid-state battery exhibits an ionic conductivity ≥1 mS / cm under a stacking pressure of less than 0.1 MPa.

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