Preparation method of solid electrolyte, solid electrolyte and all-solid-state battery

Abstract

The invention relates to the technical field of secondary batteries, in particular to a preparation method of a solid electrolyte, the solid electrolyte and an all-solid-state battery. The method comprises a mixing step, a heating step and a cooling step, in the mixing step, in a closed environment, an MOFs material and an electrolyte matrix are mixed to form a mixture, and the mass ratio of the MOFs material to the electrolyte matrix ranges from 0.7 wt% to 2.8 wt%; in the heating step, the mixture is placed in a vacuum environment, and the mixture is heated within the melting temperature range of 125-220 DEG C; in the cooling step, the mixture obtained after the heating step is completed is cooled at the cooling rate lower than 45 DEG C / min. The preparation method of the solid-state electrolyte can effectively improve the ionic conductivity of the solid-state electrolyte and the interfacial compatibility of the solid-state electrolyte and the electrode, so that the cycle performance of the all-solid-state battery is improved.

Description

Technical Field

[0001] This invention relates to the field of secondary battery technology, specifically to a method for preparing a solid electrolyte, a solid electrolyte, and an all-solid-state battery. Background Technology

[0002] With the development of electric vehicles, wearable devices, and large-scale energy storage systems, the demand for high-energy-density, high-safety, and long-life rechargeable batteries is increasing. All-solid-state batteries, as a promising alternative to these requirements, use solid-state electrolytes instead of traditional organic electrolytes. Commonly used solid-state electrolytes include sulfides, halides, and oxides.

[0003] However, existing solid-state electrolytes still have many shortcomings in terms of lithium-ion conductivity, mechanical strength, structural stability, and interfacial compatibility. For example, traditional solid-state electrolytes are usually crystalline, and the presence of grain boundaries within the particles restricts ion migration, resulting in poor ionic conductivity (especially at low temperatures). Secondly, sulfides in solid-state electrolyte materials are unstable in air and easily produce volatile gases such as hydrogen sulfide (H2S). In addition, conventional solid-state electrolytes are often brittle and prone to cracking or mechanical damage, which further affects the ionic conductivity of the electrolyte and its application in practical batteries.

[0004] Currently, surface coating is considered one of the simplest and most effective methods to improve the stability of solid-state electrolytes. Metal-organic frameworks (MOFs), as porous materials, have been used in recent years to create coatings for developing novel lithium metal solid-state electrolytes due to their tunable pore structure, high specific surface area, flexible structural design, ease of processing, excellent ion conductivity, electrochemical stability, and interfacial compatibility. However, crystalline MOF particles prepared by conventional methods are prone to structural collapse or loss of their ordered structure under high-temperature treatment or other conditions, leading to pore blockage or discontinuous ion conduction pathways. Furthermore, the interfacial discontinuities in the crystalline structure of MOF particles can result in high interfacial impedance. In addition, the rigidity of crystalline MOF materials makes it difficult to adapt to the volume changes of the electrode material during cycling after coating the surface of the solid-state electrolyte, limiting their application in solid-state batteries. Summary of the Invention

[0005] To address the above problems, this invention provides a method for preparing a solid electrolyte, a solid electrolyte, and an all-solid-state battery, which effectively improves the ionic conductivity and interfacial compatibility of the solid electrolyte with the electrode, thereby improving the cycle performance of the all-solid-state battery.

[0006] The first aspect of this invention provides a method for preparing a solid electrolyte, the method comprising a mixing step, a heating step, and a cooling step, wherein the mixing step is to mix MOFs material and an electrolyte matrix in a closed environment to form a mixture, the mass ratio of MOFs material to electrolyte matrix ranging from 0.7wt% to 2.8wt%; the heating step is to place the mixture in a vacuum environment and heat the mixture within a melting temperature range of 125℃ to 220℃; and the cooling step is to cool the mixture after the heating step at a cooling rate of less than 45℃ / min.

[0007] Optionally, the MOF materials include any one or more combinations of ZIF-8, MOF-5, ZIF-8, MIL-53, and UiO-66.

[0008] Optionally, the electrolyte matrix includes Li6PS5Cl, Li 10 GeP2S 12 Li7La3Zr2O 12 Li 1.3 Al 0.3 Ti 1.7 Any one or more combinations of (PO4)3 and Li3InCl6.

[0009] Optionally, in the mixing step, the mass ratio of MOFs material to electrolyte matrix ranges from 1.5wt% to 2.5wt%.

[0010] Optionally, in the heating step, the melting temperature range of the mixture is 150°C to 200°C.

[0011] Optionally, in the cooling step, the cooling rate of the mixture ranges from 20°C / min to 40°C / min.

[0012] A second aspect of the present invention provides a solid electrolyte prepared using the above-described method for preparing a solid electrolyte, the solid electrolyte comprising: an electrolyte matrix and MOFs material, wherein the MOFs material forms a coating layer on the surface of the electrolyte matrix.

[0013] The third aspect of the present invention provides an all-solid-state battery, which includes a positive electrode, a negative electrode, and a solid electrolyte provided in the second aspect of the present invention.

[0014] Optionally, the all-solid-state battery is an all-solid-state lithium metal battery, and the negative electrode active material in the negative electrode sheet is lithium metal.

[0015] The solid-state electrolyte preparation method provided by this invention allows for the control of the mixing ratio of MOF materials and electrolyte matrix, heating temperature, and cooling rate, transforming crystalline MOF materials into an amorphous glassy state and coating the electrolyte matrix surface. The amorphous structure of the glassy MOF materials provides more ion conduction channels for lithium ions, effectively improving the ionic conductivity of the solid-state electrolyte. Simultaneously, the glassy MOF materials exhibit better flexibility, adapting to volume changes in the electrode materials during cycling, ensuring good solid-solid interface contact between the electrode and electrolyte, thereby improving the cycle performance of the all-solid-state battery. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a method for preparing a solid electrolyte according to an embodiment of the present invention.

[0017] Figure 2 The XRD pattern of a solid electrolyte in one embodiment of the present invention is shown. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] In this document, when referring to numerical ranges, unless otherwise specified, the distribution of selectable values ​​within a numerical range is considered continuous, including the two endpoints of the range (i.e., the minimum and maximum values), and every value between these two endpoints. When multiple numerical ranges are provided to describe a feature or property, these numerical ranges can be combined.

[0020] Figure 1 This is a schematic flowchart of a solid electrolyte preparation method provided in this embodiment. (Reference) Figure 1 The method includes a mixing step S1, a heating step S2, and a cooling step S3.

[0021] The following describes the steps involved in the preparation of solid electrolytes.

[0022] <Mixing Step S1> In a closed environment, MOF materials and an electrolyte matrix are mixed to form a homogeneous mixture. In this embodiment, a sulfide electrolyte is used as the electrolyte matrix. By performing the mixing step S1 in a closed environment, external impurities can be prevented from entering the mixture; furthermore, by isolating the MOF materials and electrolyte matrix from moisture and oxygen in the air, side reactions or the generation of volatile gases such as H2S can be avoided.

[0023] In this embodiment, a planetary ball mill can be used for mechanical ball milling to ensure thorough mixing of the MOFs material and the electrolyte matrix. This guarantees that the MOFs material can uniformly cover the surface of the electrolyte matrix to form a uniform coating layer in subsequent steps. In other embodiments, other mixing methods may be used, and no specific limitations are imposed here.

[0024] As a porous material with tunable nano / sub-nano pore structure, the coating layer formed by MOFs can provide more lithium-ion conduction channels between the solid electrolyte and the electrode, thereby ensuring that the ionic conductivity of the solid electrolyte meets performance requirements. In this embodiment, the MOFs material is selected from any one or more combinations of ZIF-8, MOF-5, ZIF-8, MIL-53, and UiO-66. To ensure that the electrolyte matrix material itself has high ionic conductivity and good interfacial compatibility with the coating layer formed by MOFs, the electrolyte matrix is ​​selected as Li6PS5Cl, Li 10 GeP2S 12 Li7La3Zr2O 12 Li 1.3 Al 0.3 Ti 1.7 Any one or more combinations of (PO4)3 and Li3InCl6. In other embodiments, other types of MOF materials and electrolyte matrices may be selected according to the actual performance requirements and usage environment of the solid electrolyte and all-solid-state battery, and no specific limitations are made here.

[0025] In this embodiment, the mass ratio of MOFs material to electrolyte matrix ranges from 0.7wt% to 2.8wt%. On the one hand, this ensures that the coating layer formed by MOFs material can uniformly and completely cover the surface of the electrolyte matrix, and ensures that the coating layer has sufficient thickness to avoid harmful interfacial side reactions caused by direct contact between the electrode and the electrolyte matrix, as well as the generation of volatile gases such as H2S after the electrolyte matrix comes into contact with moisture. On the other hand, it avoids the formation of an excessively thick coating layer that hinders ion transport between the electrode and the electrolyte matrix, thereby affecting the rate or cycle performance of the battery composed of solid electrolyte.

[0026] <Heating step S2> The mixture obtained from mixing step S1 is placed in a vacuum environment and heated within a melting temperature range of 125°C to 220°C. Heating the mixture within this temperature range causes the MOFs material in the mixture to melt and transform from its original crystalline state to a glassy state. This utilizes the amorphous structure of the glassy MOFs material to provide more conduction channels between the electrolyte matrix and the electrode for lithium ions, effectively avoiding the structural collapse and discontinuous ion conduction paths that may occur with crystalline MOFs materials. Simultaneously, since the melting point of MOFs materials is typically lower than that of the solid electrolyte matrix, the electrolyte matrix remains solid during heating step S2. The molten MOFs material wets and coats the surface of the electrolyte matrix particles, forming a uniform coating layer. Preferably, the melting temperature range for heating the mixture is 150°C to 200°C. In other embodiments, the melting temperature can be adjusted to other temperature ranges and the heating time can be controlled according to the specific types of MOFs materials and electrolyte matrix in the mixture; no specific limitations are imposed here.

[0027] The heating step S2 is carried out in a vacuum environment for two reasons. First, it is to avoid side reactions such as oxidation or decomposition of the electrolyte matrix or MOFs material caused by the presence of moisture and oxygen in the environment. Second, the vacuum environment allows for the timely removal of any small amount of volatile gases that may be generated in the mixture, preventing gas residues from causing pores inside the electrolyte.

[0028] <Cooling Step S3> The mixture after heating step S2 is cooled at a rate below 45°C / min. More preferably, the cooling rate range is 20°C / min to 40°C / min. When the molten MOF material is cooled to room temperature within this cooling rate range, the atoms within the molten MOF material do not have enough time to arrange themselves in an ordered manner due to the rapid cooling, thus failing to form an ordered crystal structure. Instead, it ultimately forms a glassy MOF material with an amorphous structure, uniformly coating the electrolyte matrix to form a coating layer. This cooling rate range further avoids the formation of defects such as cracks and pores within the glassy MOF material structure, resulting in better thermal and chemical stability of the composite solid electrolyte coated with the glassy MOF material, effectively preventing interfacial side reactions during battery operation. In other embodiments, the cooling rate can be adjusted according to the type of MOF material and electrolyte matrix, as well as the actual heating temperature in heating step S2, and is not specifically limited here.

[0029] By implementing the above-described solid-state electrolyte preparation method, the original ordered crystalline structure of MOFs is transformed into a glassy structure, and the glassy MOFs material forms a coating layer on the surface of the electrolyte matrix. On one hand, the amorphous structure of the glassy MOFs material provides more channels for lithium-ion transport, thereby helping to improve the ionic conductivity between the final solid-state electrolyte and the electrode. On the other hand, compared to crystalline MOFs materials, glassy MOFs materials have better flexibility. When applied to all-solid-state batteries, this flexible coating layer can better buffer and adapt to the volume changes of the electrode material during charge-discharge cycles, ensuring a tight solid-solid interface contact between the solid electrolyte and the electrode, thereby reducing interfacial impedance, suppressing interfacial side reactions, and improving the cycle stability of the battery. Furthermore, the preparation method of this solid-state electrolyte is simple and low-cost.

[0030] This embodiment also provides a solid electrolyte, which is prepared by the above-described method for preparing a solid electrolyte. The solid electrolyte includes an electrolyte matrix and MOFs (Metal-Oxide-Factory) materials, with a coating layer formed on the surface of the electrolyte matrix by the MOFs materials. This coating layer has a glassy structure. Due to its glassy MOFs coating layer, the solid electrolyte exhibits high ionic conductivity, excellent interfacial compatibility, good thermal stability, and chemical stability. This glassy coating layer can not only act as an ion conductor but also as a gas trapping layer, effectively reducing gas generation during battery formation and charge-discharge cycles, thereby improving the battery's cycle stability.

[0031] This embodiment also provides an all-solid-state battery, which includes a positive electrode, a negative electrode, and the aforementioned solid electrolyte. Specifically, this all-solid-state battery is an all-solid-state lithium metal battery, and the negative electrode active material in the negative electrode is lithium metal. Because lithium metal has a high theoretical specific capacity and a low redox potential, using it as a negative electrode active material can help improve the energy density of the all-solid-state battery.

[0032] <Preparation of Solid Electrolytes> In this embodiment, the electrolyte matrix, MOFs material, mass ratio range of MOFs material to electrolyte matrix, and specific conditions in the preparation process of the solid electrolytes in Examples 1-17 and Comparative Examples 1-18 are all based on the values ​​in Tables 1, 2, 3, 4, and 5.

[0033] For details on the preparation of solid electrolytes in different groups of examples and comparative examples, please refer to Table 1.

[0034] The technical solution of the present invention will be described in detail below through specific embodiments and comparative examples. Unless otherwise stated, the raw materials and reagents used in the following embodiments are all commercially available products, or can be prepared by conventional methods in the art, and the instruments used in the embodiments are all commercially available.

[0035] Example 1 Li6PS5Cl was selected as the electrolyte matrix, and ZIF-8 material was selected as the MOF material. ZIF-8 material and Li6PS5Cl were mixed at a mass ratio of 2 wt%. The raw material mixture was then placed in the grinding jar of a planetary ball mill, and zirconia balls (ZrO2) with a diameter of 3 mm were added to the jar at a mass ratio of 10:1 to the raw material mixture. The mixture was then ball-milled at 300 rpm for 30 min to ensure thorough mixing of the ZIF-8 material and Li6PS5Cl. The ball milling process was conducted at room temperature, while maintaining the airtightness of the grinding jar.

[0036] The completely mixed ZIF-8 material and Li6PS5Cl mixture was then sieved out and placed in a vacuum oven. It was heated at 175°C for 30 min under vacuum and then rapidly cooled to room temperature (25°C) at a rate of 30°C / min to obtain glassy ZIF-8 material-coated Li6PS5Cl, i.e., solid electrolyte. Figure 2 The XRD pattern of Li6PS5Cl coated with glassy ZIF-8 material is shown below. Figure 2 As shown, the amorphous breadcrumb peak exhibited at a 2 theta angle of approximately 20° corresponds to the glassy state of MOF materials. Figure 2 No impurity peaks were observed in the crystalline ZIF-8 material.

[0037] Comparative Example 1 The system is the same as in Example 1, but the heating step S2 and cooling step S3 of the mixture of ZIF-8 material and Li6PS5Cl are not performed. The rest is the same as in Example 1.

[0038] Example 2 The system is the same as in Example 1, except that the MOF material used is MOF-5, and the rest is the same as in Example 1.

[0039] Comparative Example 2 The system is the same as in Example 2, except that the heating step S2 and cooling step S3 were not performed on the mixture of MOF-5 material and Li6PS5Cl. Otherwise, it is the same as in Example 2.

[0040] Example 3 The system is the same as in Example 1, except that the MOF material used is MIL-53, and the rest is the same as in Example 1.

[0041] Comparative Example 3 The system is the same as in Example 3, except that the heating step S2 and cooling step S3 were not performed on the mixture of MIL-53 material and Li6PS5Cl. Otherwise, it is the same as in Example 3.

[0042] Example 4 The system is the same as in Example 1, except that the MOF material used is UiO-66, and the rest is the same as in Example 1.

[0043] Comparative Example 4 The system is the same as in Example 4, except that the heating step S2 and cooling step S3 were not performed on the mixture of UiO-66 material and Li6PS5Cl. Otherwise, it is the same as in Example 4.

[0044] Comparative Example 5 The system is the same as in Example 1, but no MOFs material is added, and the heating step S2 and cooling step S3 are not performed. The rest is the same as in Example 1.

[0045] Comparative Example 6 The system is the same as in Example 1, except that the mass ratio of ZIF-8 material to Li6PS5Cl is 0.5 wt%, and the rest is the same as in Example 1.

[0046] Example 5 The system is the same as in Example 1, except that the mass ratio of ZIF-8 material to Li6PS5Cl is 1.0 wt%, and the rest is the same as in Example 1.

[0047] Example 6 The system is the same as in Example 1, except that the mass ratio of ZIF-8 material to Li6PS5Cl is 1.5 wt%, and the rest is the same as in Example 1.

[0048] Example 7 The system is the same as in Example 1, except that the mass ratio of ZIF-8 material to Li6PS5Cl is 2.5 wt%, and the rest is the same as in Example 1.

[0049] Comparative Example 7 The system is the same as in Example 1, except that the mass ratio of ZIF-8 material to Li6PS5Cl is 3.0 wt%, and the rest is the same as in Example 1.

[0050] Example 8 The system is the same as in Example 1, except that the melting temperature of the heating step S2 is 125 °C, and the rest is the same as in Example 1.

[0051] Example 9 The system is the same as in Example 1, except that the melting temperature of the heating step S2 is 150 °C, and the rest is the same as in Example 1.

[0052] Example 10 The system is the same as in Example 1, except that the melting temperature of the heating step S2 is 200°C, and the rest is the same as in Example 1.

[0053] Comparative Example 8 The system is the same as in Example 1, except that the melting temperature of the heating step S2 is 225°C, and the rest is the same as in Example 1.

[0054] Example 11 The system is the same as in Example 1, except that the melting temperature of the heating step S2 is 125°C and the cooling rate of the cooling step S3 is 10°C / min. The rest is the same as in Example 1.

[0055] Example 12 The system is the same as in Example 1, except that the melting temperature of the heating step S2 is 150°C and the cooling rate of the cooling step S3 is 20°C / min. The rest is the same as in Example 1.

[0056] Example 13 The system is the same as in Example 1, except that the melting temperature of the heating step S2 is 200°C and the cooling rate of the cooling step S3 is 40°C / min. The rest is the same as in Example 1.

[0057] Comparative Example 9 The system is the same as in Example 1, except that the melting temperature of the heating step S2 is 225°C and the cooling rate of the cooling step S3 is 50°C / min. The rest is the same as in Example 1.

[0058] Comparative Example 10 The system is the same as in Example 1, but without the addition of MOF materials; otherwise, it is the same as in Example 1.

[0059] Example 14 The system is the same as in Example 1, but the electrolyte matrix is ​​Li. 10 GeP2S 12 The rest is the same as in Example 1.

[0060] Comparative Example 11 The system is the same as that in Example 14, but the heating step S2 and cooling step S3 are not performed; otherwise, it is the same as that in Example 14.

[0061] Comparative Example 12 The system is the same as that in Example 14, but without the addition of MOF materials; otherwise, it is the same as that in Example 14.

[0062] Example 15 The system is the same as in Example 1, but the electrolyte matrix is ​​Li7La3Zr2O. 12 The rest is the same as in Example 1.

[0063] Comparative Example 13 The system is the same as that in Example 15, but the heating step S2 and cooling step S3 are not performed; otherwise, it is the same as that in Example 15.

[0064] Comparative Example 14 The system is the same as in Example 15, but without the addition of MOF materials; otherwise, it is the same as in Example 19.

[0065] Example 16 The system is the same as in Example 1, but the electrolyte matrix is ​​Li. 1.3 Al 0.3 Ti 1.7 (PO4)3, the rest is the same as in Example 1.

[0066] Comparative Example 15 The system is the same as that in Example 16, but the heating step S2 and cooling step S3 are not performed; otherwise, it is the same as that in Example 16.

[0067] Comparative Example 16 The system is the same as that in Example 16, but without the addition of MOF materials; otherwise, it is the same as that in Example 20.

[0068] Example 17 The system is the same as in Example 1, except that the electrolyte matrix is ​​Li3InCl6, and the rest is the same as in Example 1.

[0069] Comparative Example 17 The system is the same as that in Example 17, but the heating step S2 and cooling step S3 are not performed; otherwise, it is the same as that in Example 17.

[0070] Comparative Example 18 The system is the same as in Example 17, but without the addition of MOF materials; otherwise, it is the same as in Example 21.

[0071] The solid electrolytes of Examples 1 to 17 and Comparative Examples 1 to 18 were used in the preparation of lithium metal batteries. In the embodiments and comparative examples provided in this implementation, the electrochemical device is a lithium metal battery, and the preparation method of the lithium metal battery is as follows: <Lithium Metal Battery Assembly> A solid electrolyte was added to a sleeve and cold-pressed at 350 MPa to obtain a 300 μm thick composite solid electrolyte membrane. The cathode material was Ni. 93 (LiNi 0.93 Co0.5 Mn 0.2 A mixture of O2 material, solid electrolyte, and vapor-grown carbon fiber (VGCF) in a mass ratio of 80:19:1 is prepared. After homogenization, a positive electrode material powder is obtained. This powder is then added to a sleeve, i.e., one side of the solid electrolyte membrane, and cold-pressed at 300 MPa. A lithium metal negative electrode is then added to the other side of the solid electrolyte membrane to complete the mold battery assembly. The lithium metal negative electrode has a thickness of 200 μm and a diameter of 10 mm.

[0072] The performance of lithium metal batteries assembled from the solid electrolytes of Examples 1 to 17 and Comparative Examples 1 to 18 was tested. The test results are shown in the table, and the test methods are as follows: <Capacity retention test after 200 cycles at 0.3 C> The assembled lithium metal battery was tested at a voltage range of 2.5~4.3 V and a temperature of 25 °C. Constant current and constant voltage charge-discharge cycle tests were conducted at a current of 0.3 C and a pressure of 10 MPa to verify the cycle stability of the solid electrolyte produced by the solid electrolyte manufacturing method provided in this embodiment for lithium metal batteries.

[0073] Table 1. Performance test results of lithium metal batteries in Examples 1-4 and Comparative Examples 1-5

[0074] Table 2. Performance test results of lithium metal batteries in Examples 1, 5-7 and Comparative Examples 5-7

[0075] Table 3. Performance test results of lithium metal batteries in Examples 1, 8-10 and Comparative Examples 1, 5, and 8

[0076] Table 4. Performance test results of lithium metal batteries in Examples 1, 11-13 and Comparative Examples 1 and 5

[0077] Table 5. Performance test results of lithium metal batteries in Examples 1, 14-17 and Comparative Examples 1, 10-18

[0078] Analyzing the above data, we can draw the following conclusions: (1) The comparison results of the lithium metal battery performance test data of Examples 1-4 and Comparative Examples 1-5 in Table 1 show that, compared with the solid electrolyte without MOFs, the all-solid-state battery assembled with the solid electrolyte containing MOFs has a certain improvement in capacity retention after 200 cycles at 0.3 C. Moreover, the solid electrolyte manufactured by the manufacturing method provided in this embodiment can further improve the capacity retention of the all-solid-state battery after 200 cycles at 0.3 C.

[0079] (2) The comparison results of the lithium metal battery performance test data of Examples 1, 5-7 and Comparative Examples 5-7 in Table 2 show that, in order to maintain a good capacity retention rate of the all-solid-state battery after 200 cycles at 0.3 C, the preferred mass ratio of MOFs material to electrolyte matrix in this embodiment is 1.0 wt%-2.5 wt%. (3) According to the comparison results of the lithium metal battery performance test data of Examples 1, 8-10 and Comparative Examples 1, 5 and 8 in Table 3, if the capacity retention rate of the all-solid-state battery is to be maintained at a good level after 200 cycles at 0.3 C, the melting temperature range for heating the mixture in this embodiment is preferably 125℃~200℃.

[0080] (4) According to the comparison results of the lithium metal battery performance test data of Examples 1, 11-13 and Comparative Examples 1 and 5 in Table 4, if the capacity retention rate of the all-solid-state battery is to be maintained at a good level after 200 cycles at 0.3 C, the cooling rate range of the mixture in this embodiment is preferably 10℃ / min to 40℃ / min.

[0081] (5) The comparison results of the lithium metal battery performance test data of Examples 1, 14-17 and Comparative Examples 1, 10-18 in Table 5 show that, with Li 10 GeP2S 12 Li6PS5Cl, Li7La3Zr2O 12 Li 1.3 Al 0.3 Ti 1.7 Both (PO4)3 and Li3InCl6, as electrolyte substrates, can improve the capacity retention rate of the all-solid-state battery provided by this embodiment after 200 cycles at 0.3 C.

[0082] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a solid electrolyte, characterized in that, include: The mixing step involves mixing MOF materials and an electrolyte matrix in a closed environment to form a mixture, wherein the mass ratio of the MOF materials to the electrolyte matrix ranges from 0.7 wt% to 2.8 wt%. The heating step involves placing the mixture in a vacuum environment and heating it within a melting temperature range of 125°C to 220°C. The cooling step involves cooling the mixture that has undergone the heating step at a rate of less than 45°C / min.

2. The method for preparing a solid electrolyte as described in claim 1, characterized in that, The MOF materials include any one or more combinations of ZIF-8, MOF-5, ZIF-8, MIL-53, and UiO-66.

3. The method for preparing a solid electrolyte as described in claim 1, characterized in that, The electrolyte matrix includes Li6PS5Cl and Li 10 GeP2S 12 Li7La3Zr2O 12 Li 1.3 Al 0.3 Ti 1.7 Any one or more combinations of (PO4)3 and Li3InCl6.

4. The method for preparing a solid electrolyte as described in claim 1, characterized in that, In the mixing step, the mass ratio of the MOF material to the electrolyte matrix ranges from 1.5 wt% to 2.5 wt%.

5. The method for preparing a solid electrolyte as described in claim 1, characterized in that, In the heating step, the melting temperature range of the mixture is 150°C to 200°C.

6. The method for preparing a solid electrolyte as described in claim 1, characterized in that, In the cooling step, the cooling rate of the mixture ranges from 20°C / min to 40°C / min.

7. A solid electrolyte, prepared using the method for preparing a solid electrolyte as described in any one of claims 1-6, characterized in that, include: Electrolyte matrix, MOFs material, wherein the MOFs material forms a coating layer on the surface of the electrolyte matrix.

8. An all-solid-state battery, characterized in that, The all-solid-state battery includes a positive electrode, a negative electrode, and a solid electrolyte as described in claim 7.

9. The all-solid-state battery as described in claim 8, characterized in that, The all-solid-state battery is an all-solid-state lithium metal battery, and the negative electrode active material in the negative electrode sheet is lithium metal.

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