Electrolyte and preparation method thereof

Abstract

The invention relates to the technical field of lithium battery electrolytes, in particular to an electrolyte and a preparation method thereof, and the method comprises the following steps: preparing a local high-concentration electrolyte; providing epoxy resin and a curing agent thereof, and blending the local high-concentration electrolyte, the epoxy resin and the curing agent thereof to obtain a pouring solution; providing glass fibers, infiltrating the pouring liquid into the glass fibers, and performing in-situ curing on the infiltrated glass fibers to obtain the electrolyte. According to the electrolyte and the preparation method thereof provided by the invention, the technical problems of poor mechanical strength and low conductivity of a solid electrolyte can be solved.

Description

[Technical Field]

[0001] This invention relates to the field of lithium battery electrolyte technology, and in particular to an electrolyte and its preparation method. [Background Technology]

[0002] Lithium-ion batteries play a crucial role in renewable energy storage, but current lithium-ion batteries struggle to meet the energy density, safety, and cost requirements of large-scale energy storage. Current research on lithium-ion batteries has diverged into two approaches: one is to continue optimizing traditional lithium-ion batteries, and the other is to boldly improve the core components of the battery to develop next-generation batteries. Solid-state batteries, in particular, have attracted attention due to their higher safety, energy density, and longer cycle life.

[0003] Compared to traditional lithium-ion batteries, solid-state batteries have a significant advantage in safety due to their higher safety levels. This is because solid-state batteries do not contain flammable organic electrolytes, and the solid electrolyte itself is non-flammable. Solids also exhibit slower side reactions compared to liquids, resulting in longer cycle life. Furthermore, many aging factors present in traditional lithium-ion batteries have a smaller impact on solid-state batteries, such as the dissolution of transition metals. However, while solid-state electrolytes can withstand dendrite impacts for short periods compared to liquid electrolytes, during long-term battery cycling, the continuous deformation caused by external forces leads to the gradual accumulation of residual stress within the membrane, ultimately causing material failure. Therefore, mechanical degradation is a more severe issue in solid-state batteries.

[0004] It is worth noting that in solid electrolytes, the presence of polymer organic components or the difficulty in resolving the interface problem between inorganic electrolytes significantly reduces the conductivity between the electrolyte and the electrodes, inevitably increasing the overall electrolyte resistance. Therefore, finding a new design method and approach to simultaneously meet the requirements of solid electrolytes while simultaneously considering the needs for mechanical strength and conductivity is particularly important. [Summary of the Invention]

[0005] To address the technical problems of poor mechanical strength and low conductivity in solid electrolytes, this invention provides an electrolyte and its preparation method.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: an electrolyte preparation method, the method comprising: preparing a locally high-concentration electrolyte; providing an epoxy resin and its curing agent, mixing the locally high-concentration electrolyte, the epoxy resin and its curing agent, and using the locally high-concentration electrolyte to induce microphase separation of the epoxy resin to obtain a casting liquid; providing glass fibers, impregnating the casting liquid into the interior of the glass fibers, and curing the impregnated glass fibers in situ to obtain the electrolyte.

[0007] Preferably, the locally high-concentration electrolyte comprises 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE), ethylene glycol dimethyl ether (DME), and lithium salt.

[0008] Preferably, the volume ratio of the ethylene glycol dimethyl ether to 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether is (80%–20%):(20%–80%).

[0009] Preferably, the lithium salt is LiTFSI or LiFSI, and the concentration of the lithium salt is 0.5M to 1.5M.

[0010] Preferably, the mass ratio of the locally high-concentration electrolyte: epoxy resin: curing agent is (1-10): 1: (0.1-0.5).

[0011] Preferably, the epoxy resin is epoxy resin E 54, and the curing agent is a diethylenetriamine curing agent specifically for epoxy resin E 54.

[0012] Preferably, the glass fiber has a thickness of 100μm to 500μm and a cross-sectional diameter of 19mm.

[0013] Preferably, the step of immersing the casting liquid into the glass fiber and curing the immersed glass fiber in situ to obtain the electrolyte includes: immersing the casting liquid into the glass fiber to obtain a wet film, treating the wet film at a first temperature for a first duration, and then treating it at a second temperature for a second duration to complete the curing process and obtain the electrolyte; the second temperature is greater than the first temperature.

[0014] Preferably, the wet film is heated to 30-60°C at a rate of 0.2-2°C / min on a hot press and cured at a constant temperature for 2-8 hours. Subsequently, the temperature is increased to 80-100°C at a rate of 1-3°C / min and kept at a constant temperature for 30-150 minutes.

[0015] To solve the above-mentioned technical problems, the present invention provides another technical solution as follows: an electrolyte, which is prepared by the above-mentioned electrolyte preparation method.

[0016] Compared with the prior art, the electrolyte and its preparation method provided by the present invention have the following advantages:

[0017] 1. This invention provides an electrolyte and its preparation method, the method comprising: preparing a locally high-concentration electrolyte; providing an epoxy resin and its curing agent; mixing the locally high-concentration electrolyte, epoxy resin and its curing agent; inducing microphase separation of the epoxy resin using the locally high-concentration electrolyte to obtain a casting liquid; providing glass fibers; impregnating the glass fibers with the casting liquid; and curing the impregnated glass fibers in situ to obtain the electrolyte. This invention uses glass fibers as a substrate, impregnates a composite slurry of epoxy resin and locally high-concentration electrolyte into its bulk phase, induces microphase separation of the epoxy resin using the locally high-concentration electrolyte, and further cures the epoxy resin in situ, thereby obtaining a highly conductive and mechanically load-bearing structured electrolyte, achieving the effect of a solid electrolyte integrating high mechanical load-bearing capacity, structure, and high conductivity.

[0018] 2. This invention provides an electrolyte and its preparation method, wherein the locally high-concentration electrolyte comprises 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE), dimethyl ethylene glycol ether (DME), and lithium salt. The locally high-concentration electrolyte optimizes the electrochemical reaction and improves battery efficiency and lifespan by forming a high-concentration electrolyte region near the electrode surface.

[0019] 3. The present invention provides an electrolyte and its preparation method, wherein the volume ratio of ethylene glycol dimethyl ether to 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether is (80%~20%):(20%~80%), so as to improve the performance of locally high-concentration electrolyte.

[0020] 4. This invention provides an electrolyte and its preparation method, wherein the lithium salt is LiTFSI or LiFSI, and the concentration of the lithium salt is 0.5M to 1.5M. The lithium salt typically acts as a conductor of ions, ensuring ion transport within the battery, thereby enabling the battery to function normally.

[0021] 5. The present invention provides an electrolyte and its preparation method, wherein the mass ratio of the locally high-concentration electrolyte: epoxy resin: curing agent is (1-10):1:(0.1-0.5), so as to better utilize the locally high-concentration electrolyte to induce the separation of epoxy resin microphase in the glass fiber bulk phase and to cure it in situ in one step.

[0022] 6. The present invention provides an electrolyte and its preparation method, wherein the epoxy resin is epoxy resin E 54, and the curing agent is a diethylenetriamine curing agent specifically for epoxy resin E 54. In-situ curing of the epoxy resin provides good mechanical properties to the glass fiber, and the curing agent enables the epoxy resin to form a stable solid structure with the required physical properties and chemical stability.

[0023] 7. The present invention provides an electrolyte and its preparation method, wherein the glass fiber has a thickness of 100 μm to 500 μm and a cross-sectional diameter of 19 mm. The porous structure of the glass fiber allows the electrolyte to maintain its advantages of structure and high conductivity.

[0024] 8. An electrolyte and its preparation method provided by the present invention, wherein the step of impregnating the glass fiber with a casting liquid and curing the impregnated glass fiber in situ to obtain the electrolyte comprises: impregnating the glass fiber with the casting liquid to obtain a wet film, treating the wet film at a first temperature for a first duration, and then treating it at a second temperature for a second duration to complete the curing to obtain the electrolyte; the second temperature is greater than the first temperature to enhance the mechanical properties, durability and electrical properties of the composite material.

[0025] 9. The present invention provides an electrolyte and its preparation method, wherein the wet film is heated to 30-60°C at 0.2-2°C / min on a hot press and cured at a constant temperature for 2-8 hours, and then heated to 80-100°C at 1-3°C / min and cured at a constant temperature for 30-150 minutes, thereby obtaining an electrolyte with high conductivity and high mechanical load-bearing structure.

[0026] 10. The electrolyte provided by the present invention has the same beneficial effects as the electrolyte and its preparation method described above, and will not be repeated here. [Attached Image Description]

[0027] Figure 1 This is a flowchart of the steps of an electrolyte preparation method provided in the first embodiment of the present invention.

[0028] Figure 2 This is a schematic diagram of the electrolyte sample prepared according to the present invention.

[0029] Figure 3 This is the electrolyte resistance test prepared according to the third embodiment of the present invention. Figure 1 .

[0030] Figure 4 This is the electrolyte resistance test prepared according to the third embodiment of the present invention. Figure 2 .

Detailed Implementation Methods

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0032] It should be noted that microphase separation refers to the phase separation phenomenon that occurs at the nanometer or micrometer scale in a polymer system, where polymer segments with different chemical compositions or physical properties separate. This invention uses commercial glass fiber as a substrate. By impregnating a composite slurry of epoxy resin and locally high-concentration electrolyte into its bulk phase, the locally high-concentration electrolyte induces microphase separation of the epoxy resin, and the epoxy resin is then cured in situ in one step, resulting in a highly conductive and mechanically robust electrolyte structure.

[0033] Please see Figure 1 The first embodiment of the present invention provides a method for preparing an electrolyte, the method comprising:

[0034] S1: Prepare a locally high-concentration electrolyte;

[0035] S2: Provide epoxy resin and its curing agent, mix local high-concentration electrolyte, epoxy resin and its curing agent, and use local high-concentration electrolyte to induce micro-phase separation of epoxy resin to obtain casting liquid;

[0036] S3: Provide glass fibers, impregnate the glass fibers with casting liquid, and solidify the impregnated glass fibers in situ to obtain electrolyte.

[0037] It should be noted that this invention obtains a casting liquid by blending a locally high-concentration electrolyte, epoxy resin, and its curing agent, and then impregnates the casting liquid into the interior of glass fibers and cures it in situ to obtain a high-performance electrolyte with both mechanical strength and electrical conductivity. Specifically, in this scheme, the locally high-concentration electrolyte, epoxy resin, and its curing agent are blended, and the locally high-concentration electrolyte induces microphase separation of the epoxy resin. This microphase separation phenomenon can create a unique microstructure, which can maintain the high mechanical strength of the epoxy resin and ensure the high conductivity of the electrolyte components, thus achieving effective integration of the two. Furthermore, glass fiber is used as a substrate, and a composite slurry of epoxy resin and locally high-concentration electrolyte is impregnated into its bulk phase. The epoxy resin is then further cured in situ. The porous structure of the glass fiber is conducive to maintaining the structure and high conductivity of the electrolyte, while its high strength characteristics also significantly enhance the overall mechanical stability. Finally, a high-conductivity, high-mechanical-load-bearing structural electrolyte is obtained, which has the advantages of high yield, high conductivity, and high mechanical load-bearing capacity. It can be directly used as a rigid structural component of a battery and as an electrolyte in a battery, showing good prospects.

[0038] Specifically, the local high-concentration electrolyte consists of 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE), dimethyl ethylene glycol ether (DME), and lithium salt, in order to take into account the role of microphase separation during in-situ solidification.

[0039] Furthermore, the volume ratio of ethylene glycol dimethyl ether to 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether is (80%–20%):

[0040] (20%–80%), to obtain a better lithium salt solvation structure.

[0041] Furthermore, the lithium salt is LiTFSI or LiFSI, and the lithium salt concentration is 0.5M to 1.5M.

[0042] It should be noted that the composition and ratio of the locally high-concentration electrolyte work together to achieve the characteristics of locally high concentration, thereby improving the performance and effectiveness of the locally high-concentration electrolyte.

[0043] Specifically, in step S2, the mass ratio of locally high-concentration electrolyte: epoxy resin: curing agent is (1-10):1:(0.1-0.5). It should be noted that an imbalance in the ratio of locally high-concentration electrolyte, epoxy resin, and curing agent may lead to incomplete curing, inconsistent material properties, and instability in the chemical structure of the material, affecting the performance and quality of the final cured material.

[0044] Furthermore, the epoxy resin is epoxy resin E 54, and the curing agent is a diethylenetriamine curing agent specifically for epoxy resin E 54.

[0045] Specifically, in step S3, the glass fiber thickness is 100μm to 500μm, and the cross-sectional diameter is 19mm. The in-situ curing of epoxy resin provides the glass fiber with good mechanical properties, giving it high mechanical load-bearing capacity; and the porous structure of the glass fiber allows the electrolyte to maintain its structured properties and high conductivity.

[0046] Furthermore, the volume of the casting liquid corresponding to the glass fiber is 30-300 μL.

[0047] Specifically, step S5 includes the following steps:

[0048] A wet film is obtained by impregnating the glass fiber with the casting liquid;

[0049] After treating the wet membrane at a first constant temperature for a first duration;

[0050] The electrolyte is obtained by maintaining a constant temperature at a second temperature for a second duration.

[0051] It should be noted that the second temperature is higher than the first temperature. The in-situ curing process uses two different temperatures for curing to optimize the mechanical properties of the material and the curing process.

[0052] Furthermore, step S5 specifically includes: heating the wet film to 30-60°C at 0.2-2°C / min on a hot press, and curing it at a constant temperature for 2-8 hours; then heating it to 80-100°C at 1-3°C / min and holding it at a constant temperature for 30-150 minutes.

[0053] The second embodiment of the present invention provides a method for preparing an electrolyte, the method comprising:

[0054] (1) Prepare a local high-concentration electrolyte with a LiTFSI concentration of 1M, a TTE content of 70%, and a DME content of 30%;

[0055] (2) The local high-concentration electrolyte obtained in the previous step is mixed with epoxy resin E 54 and curing agent in a mass ratio of 10:1:0.3 to obtain the casting liquid;

[0056] (3) Measure 150 μL of the casting liquid obtained in the previous step and coat it evenly on a glass fiber with a thickness of 260 μm to obtain a wet film. Then, on a hot press, heat the wet film to 40°C at 0.5°C / min and cure it at a constant temperature for 5 hours. Subsequently, heat it to 80°C at 2°C / min and cure it at a constant temperature for 60 minutes to obtain a high conductivity and high mechanical load-bearing structure electrolyte.

[0057] It should be noted that the electrolyte obtained in this embodiment has a conductivity of up to 2.6 mS / cm and a tensile strength of up to 1527 N at room temperature.

[0058] The third embodiment of the present invention provides a method for preparing an electrolyte, the method comprising:

[0059] (1) Prepare a local high-concentration electrolyte with LiTFSI concentration of 0.5M, TTE content of 60%, and DME content of 40%;

[0060] (2) The local high-concentration electrolyte obtained in the previous step is mixed with epoxy resin E 54 and curing agent in a mass ratio of 8:1:0.2 to obtain the casting liquid;

[0061] (3) Measure 180 μL of the casting liquid obtained in the previous step and coat it evenly on a glass fiber with a thickness of 300 μm to obtain a wet film. On a hot press, heat the wet film to 30°C at 1°C / min and cure it at a constant temperature for 6 hours. Then, heat it to 90°C at 1°C / min and cure it at a constant temperature for 40 minutes to obtain a high conductivity and high mechanical load-bearing structure electrolyte.

[0062] It should be noted that the electrolyte obtained in this embodiment has a conductivity of up to 1.7 mS / cm and a tensile strength of up to 1904 N at room temperature.

[0063] Please see Figure 3 and Figure 4 The conductivity is calculated based on the resistance value obtained from the electrolyte resistance test diagram in this embodiment.

[0064] The fourth embodiment of the present invention provides a method for preparing an electrolyte, the method comprising:

[0065] (1) Prepare a local high-concentration electrolyte with Li FSI concentration of 1M, TTE content of 80%, and DME content of 20%;

[0066] (2) The local high-concentration electrolyte obtained in the previous step is mixed with epoxy resin E 54 and curing agent in a mass ratio of 6:1:0.1 to obtain the casting liquid;

[0067] (3) Measure 150 μL of the casting liquid obtained in the previous step and coat it evenly on a glass fiber with a thickness of 260 μm to obtain a wet film. On a hot press, heat the wet film to 40°C at 0.8°C / min and cure it at a constant temperature for 4 hours. Then, heat it to 100°C at 3°C / min and cure it at a constant temperature for 30 minutes to obtain a high conductivity and high mechanical load-bearing structure electrolyte.

[0068] It should be noted that the electrolyte prepared in this embodiment has a conductivity of up to 1.3 mS / cm and a tensile strength of up to 2272 N at room temperature.

[0069] The fifth embodiment of the present invention provides a method for preparing an electrolyte, the method comprising:

[0070] (1) Prepare a local high-concentration electrolyte with Li FSI concentration of 1.5M, TTE content of 50%, and DME content of 50%;

[0071] (2) The local high-concentration electrolyte obtained in the previous step is mixed with epoxy resin E 54 and curing agent in a mass ratio of 9:1:0.2 to obtain the casting liquid;

[0072] (3) Measure 120 μL of casting liquid and coat it evenly on a glass fiber with a thickness of 350 μm to obtain a wet film. On a hot press, heat the wet film to 60 °C at 1 °C / min and keep it at a constant temperature for 3 h. Then, heat it to 80 °C at 2 °C / min and keep it at a constant temperature for 90 min to obtain a high conductivity and high mechanical load-bearing structure electrolyte.

[0073] It should be noted that the electrolyte prepared in this embodiment has a conductivity of up to 2.1 mS / cm and a tensile strength of up to 1821 N at room temperature.

[0074] Please see Figure 2The sixth embodiment of the present invention provides an electrolyte prepared by the electrolyte preparation method provided in any of the above embodiments. The electrolyte prepared by this method has advantages such as high yield, high conductivity, and high mechanical load-bearing capacity, and can be directly used as a rigid structural component of a battery and as an electrolyte in a battery, showing promising prospects.

[0075] In the embodiments provided by this invention, it should be understood that "B corresponding to A" means that B is associated with A, and B can be determined based on A. However, it should also be understood that determining B based on A does not mean determining B solely based on A; B can also be determined based on A and / or other information.

[0076] It should be understood that the phrase "one embodiment" or "an embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of the invention. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Those skilled in the art should also recognize that the embodiments described in the specification are optional embodiments, and the actions and modules involved are not necessarily essential to the invention.

[0077] In various embodiments of the present invention, it should be understood that the sequence number of each process does not necessarily imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0078] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It is particularly important to note that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0079] Compared with the prior art, the electrolyte and its preparation method provided by the present invention have the following beneficial effects:

[0080] 1. This invention provides an electrolyte and its preparation method, the method comprising: preparing a locally high-concentration electrolyte; providing an epoxy resin and its curing agent; mixing the locally high-concentration electrolyte, epoxy resin and its curing agent; inducing microphase separation of the epoxy resin using the locally high-concentration electrolyte to obtain a casting liquid; providing glass fibers; impregnating the glass fibers with the casting liquid; and curing the impregnated glass fibers in situ to obtain the electrolyte. This invention uses glass fibers as a substrate, impregnates a composite slurry of epoxy resin and locally high-concentration electrolyte into its bulk phase, induces microphase separation of the epoxy resin using the locally high-concentration electrolyte, and further cures the epoxy resin in situ, thereby obtaining a highly conductive and mechanically load-bearing structured electrolyte, achieving the effect of a solid electrolyte integrating high mechanical load-bearing capacity, structure, and high conductivity.

[0081] 2. This invention provides an electrolyte and its preparation method, wherein the locally high-concentration electrolyte comprises 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE), dimethyl ethylene glycol ether (DME), and lithium salt. The locally high-concentration electrolyte optimizes the electrochemical reaction and improves battery efficiency and lifespan by forming a high-concentration electrolyte region near the electrode surface.

[0082] 3. The present invention provides an electrolyte and its preparation method, wherein the volume ratio of ethylene glycol dimethyl ether to 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether is (80%~20%):(20%~80%), so as to improve the performance of locally high-concentration electrolyte.

[0083] 4. This invention provides an electrolyte and its preparation method, wherein the lithium salt is LiTFSI or LiFSI, and the concentration of the lithium salt is 0.5M to 1.5M. The lithium salt typically acts as a conductor of ions, ensuring ion transport within the battery, thereby enabling the battery to function normally.

[0084] 5. The present invention provides an electrolyte and its preparation method, wherein the mass ratio of the locally high-concentration electrolyte: epoxy resin: curing agent is (1-10):1:(0.1-0.5), so as to better utilize the locally high-concentration electrolyte to induce the separation of epoxy resin microphase in the glass fiber bulk phase and to cure it in situ in one step.

[0085] 6. The present invention provides an electrolyte and its preparation method, wherein the epoxy resin is epoxy resin E 54, and the curing agent is a diethylenetriamine curing agent specifically for epoxy resin E 54. In-situ curing of the epoxy resin provides good mechanical properties to the glass fiber, and the curing agent enables the epoxy resin to form a stable solid structure with the required physical properties and chemical stability.

[0086] 7. The present invention provides an electrolyte and its preparation method, wherein the glass fiber has a thickness of 100 μm to 500 μm and a cross-sectional diameter of 19 mm. The porous structure of the glass fiber allows the electrolyte to maintain its advantages of structure and high conductivity.

[0087] 8. An electrolyte and its preparation method provided by the present invention, wherein the step of impregnating the glass fiber with a casting liquid and curing the impregnated glass fiber in situ to obtain the electrolyte comprises: impregnating the glass fiber with the casting liquid to obtain a wet film, treating the wet film at a first temperature for a first duration, and then treating it at a second temperature for a second duration to complete the curing to obtain the electrolyte; the second temperature is greater than the first temperature to enhance the mechanical properties, durability and electrical properties of the composite material.

[0088] 9. The present invention provides an electrolyte and its preparation method, wherein the wet film is heated to 30-60°C at 0.2-2°C / min on a hot press and cured at a constant temperature for 2-8 hours, and then heated to 80-100°C at 1-3°C / min and cured at a constant temperature for 30-150 minutes, thereby obtaining an electrolyte with high conductivity and high mechanical load-bearing structure.

[0089] 10. The electrolyte provided by the present invention has the same beneficial effects as the electrolyte and its preparation method described above, and will not be repeated here.

[0090] The present invention has provided a detailed description of an electrolyte and its preparation method according to embodiments. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention. Any modifications, equivalent substitutions, and improvements made within the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing an electrolyte, characterized in that, The method includes: Preparation of locally high-concentration electrolyte; Epoxy resin and its curing agent are provided. A local high-concentration electrolyte, epoxy resin and its curing agent are mixed. The local high-concentration electrolyte is used to induce the separation of the epoxy resin microphase to obtain a casting liquid. Glass fibers are provided, and a casting liquid is impregnated into the interior of the glass fibers. The impregnated glass fibers are then cured in situ to obtain the electrolyte.

2. The electrolyte preparation method according to claim 1, characterized in that: The locally concentrated electrolyte comprises 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE), ethylene glycol dimethyl ether (DME), and lithium salt.

3. The electrolyte preparation method according to claim 2, characterized in that: The volume ratio of the ethylene glycol dimethyl ether to 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether is (80%–20%): (20%–80%).

4. The electrolyte preparation method according to claim 2, characterized in that: The lithium salt is LiTFSI or LiFSI, and the concentration of the lithium salt is 0.5M to 1.5M.

5. The electrolyte preparation method according to claim 1, characterized in that: The mass ratio of the locally high-concentration electrolyte, epoxy resin, and curing agent is (1-10):1:(0.1-0.5).

6. The electrolyte preparation method according to claim 1, characterized in that: The epoxy resin is epoxy resin E54, and the curing agent is a diethylenetriamine curing agent specifically for epoxy resin E54.

7. The electrolyte preparation method according to claim 1, characterized in that: The glass fiber has a thickness of 100μm to 500μm and a cross-sectional diameter of 19mm.

8. The electrolyte preparation method according to claim 1, characterized in that, The step of immersing the casting liquid into the glass fiber and then curing the immersed glass fiber in situ to obtain the electrolyte includes: immersing the casting liquid into the glass fiber to obtain a wet film, treating the wet film at a first temperature for a first duration, and then treating it at a second temperature for a second duration to complete the curing process and obtain the electrolyte; the second temperature is greater than the first temperature.

9. The electrolyte preparation method according to claim 8, characterized in that: On a hot press, the wet film is heated to 30-60°C at a rate of 0.2-2°C / min and cured at a constant temperature for 2-8 hours. Subsequently, the temperature is increased to 80-100°C at a rate of 1-3°C / min and cured at a constant temperature for 30-150 minutes.

10. An electrolyte, characterized in that: It is prepared by the electrolyte preparation method according to any one of claims 1-9.

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