Solid electrolyte thin film and method for manufacturing the same

Abstract

The application relates to a solid electrolyte thin film and a preparation method thereof. The method comprises uniformly dispersing carbon-based nanomaterial and proton-conducting material in a polyvinylidene fluoride (PVDF) solution, and preparing a double-ion-conductor solid electrolyte thin film with a nano-pore channel structure through electrospinning and a template method. During the preparation process, the voltage, flow rate and receiving distance are controlled to ensure the uniformity of the channel structure and the conductivity. The obtained thin film achieves a good balance between high ion mobility and mechanical strength, and is suitable for high-performance energy storage devices, such as solid-state batteries. The electrolyte thin film shows excellent electrochemical performance and long cycle life.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electrolyte thin films, in particular to a solid electrolyte thin film and a preparation method thereof. BACKGROUND

[0002] With the continuous growth of modern energy demand, energy storage technology, especially battery technology, has developed rapidly. Among many energy storage technologies, solid-state batteries have gradually become an important development direction in the field of new energy due to their high energy density, long service life and good rate performance. Solid-state batteries are not only applied to high-energy consumption devices such as new energy vehicles, high-speed motors and submarines, but also widely used in daily devices such as mobile communications. Compared with traditional liquid electrolyte batteries, solid-state batteries have obvious advantages in safety, operating temperature range and energy density. Especially in terms of safety, solid-state batteries greatly reduce the safety hazards in use due to the absence of liquid electrolyte leakage risk. Therefore, solid-state batteries are considered to be one of the important development directions of future energy storage technology.

[0003] Although solid-state battery technology is constantly improving, there are still many deficiencies in existing technologies, which limit its further popularization and application. First, traditional inorganic electrolytes and polymer electrolyte materials each have their own inherent defects. Although inorganic electrolytes have high ionic conductivity and excellent thermal stability, their preparation process is complex and brittle, making it difficult to achieve large-scale production in practical applications. Polymer electrolytes have low ionic conductivity at room temperature and are not suitable for high-voltage high-current density environments, limiting their application range. In addition, existing composite solid-state electrolytes still have a lot of room for optimization in terms of improving ionic conductivity and mechanical properties. The interface bonding force and stability of the composite material, as well as the uniformity control of the material during the preparation process, have an important impact on the performance of the final product.

[0004] For example, Chinese patent (CN114188603B) discloses a nano-phase-separated solid polymer electrolyte thin film and its preparation method and application. The thin film uses a polystyrene-maleic anhydride random copolymer as a rigid main chain, and grafts small molecular weight polyethylene glycol segments on the main chain to obtain a polymer solid electrolyte thin film with a nano-phase-separated structure by solution casting. This technical solution realizes the decoupling of the mechanical properties and lithium ion conductivity of the polymer solid electrolyte through the design of the polymer molecular structure, and the obtained nano-phase-separated solid polymer electrolyte simultaneously has excellent mechanical properties, high ionic conductivity and a wide electrochemical window.

[0005] For another example, Chinese patent (CN118117148A) discloses a preparation method of a composite solid electrolyte film. The steps include: S1, preparing a graphite-like carbon nitride powder; S2, mixing the graphite-like carbon nitride powder and polyvinylidene fluoride to prepare a first configuration precursor solution; S3, preparing a polyvinylidene fluoride fiber membrane by electrospinning method; S4, taking the graphite-like carbon nitride powder as a filler and preparing a second configuration precursor solution with polyethylene oxide; S5, pouring the second configuration precursor solution into the polyvinylidene fluoride fiber membrane to obtain a composite solid electrolyte film. This technical solution makes the composite solid electrolyte film have strong stability and high conductivity, which is beneficial to improve the electrochemical performance and mechanical properties of solid-state batteries.

[0006] The existing technology has made certain progress in improving the performance of solid electrolyte films, but none of them involves the design of dual-ion conductors. The introduction of electronic and proton-conducting dual-ion conductor solid electrolyte films will effectively improve the overall performance of the battery, especially in applications that require simultaneous electron and proton conduction. This innovative dual-ion conductor system has significant technical advantages and wide application prospects, and is an important direction for the development of future solid-state battery technology. SUMMARY

[0007] The existing technology has made certain progress in improving the performance of solid electrolyte films, but none of them involves the design of dual-ion conductors. The introduction of electronic and proton-conducting dual-ion conductor solid electrolyte films will effectively improve the overall performance of the battery, especially in applications that require simultaneous electron and proton conduction. This innovative dual-ion conductor system has significant technical advantages and wide application prospects, and is an important direction for the development of future solid-state battery technology.

[0008] The present application provides a preparation method of a solid electrolyte film, which includes the following technical steps:

[0009] Dissolve polyvinylidene fluoride (PVDF) in an appropriate amount of N,N-dimethylacetamide (DMF) and stir until completely dissolved to obtain a uniform PVDF solution; disperse the carbon-based nanomaterial in ethanol and use ultrasonic treatment to obtain a uniform dispersion to obtain a conductive material dispersion; disperse the proton-conducting material in ethanol and uniformly disperse by ultrasonic treatment to obtain a proton-conducting material dispersion; add the conductive material dispersion to the PVDF solution and stir thoroughly to obtain a mixed precursor solution; fix the template material on the fiber receiver of the electrospinning device and load the mixed precursor solution into the syringe of the electrospinning device; adjust the voltage and flow rate to perform electrospinning to prepare a PVDF fiber membrane containing carbon-based nanomaterial; dissolve a certain proportion of polyethylene oxide (PEO) and the proton-conducting material in ethanol to form a second configuration precursor solution; uniformly cast the second configuration precursor solution on the PVDF fiber membrane, stand for a period of time, and allow it to fully soak; perform curing treatment on the cast composite membrane, immerse the cured composite membrane in a dissolving agent to remove the template material, and then perform vacuum drying treatment to obtain a double-ion-conductor solid electrolyte thin film with a nano-pore structure.

[0010] By adopting the above technical scheme, firstly, polyvinylidene fluoride (PVDF) is dissolved in N,N-dimethylacetamide (DMF) to obtain a uniform PVDF solution, which provides a good base for the uniform dispersion of carbon-based nanomaterials in the subsequent process. The carbon-based nanomaterials (such as graphene or carbon nanotubes) and the proton-conducting material are uniformly dispersed in ethanol by ultrasonic treatment to form a dispersion of conductive material and proton-conducting material. This step ensures the full dispersion and uniformity of each functional material. Subsequently, the conductive material dispersion is mixed with the PVDF solution and stirred uniformly to form a mixed precursor solution, which ensures the uniform distribution of the conductive nanomaterials in the base, thereby enhancing the conductivity of the final film. Then, in the electrospinning process, the mixed precursor solution is precisely controlled by a syringe and coated on a fiber receiver to form a PVDF fiber membrane. The use of a template material further ensures the formation of a nanopore structure. By adjusting the voltage and flow rate, the fiber membrane obtains a uniform and controllable pore structure during formation. These pores provide a path for efficient ion conduction, thereby optimizing the electrochemical performance of the electrolyte. Thereafter, a second configuration precursor solution of polyethylene oxide (PEO) and proton-conducting material is cast on the fiber membrane to ensure full infiltration, ensuring uniform distribution and full contact of the proton conductor material, thereby improving the efficiency of proton conduction. Finally, through solidification treatment and dissolution to remove the template material, a stable nanopore structure is formed, and vacuum drying further enhances the mechanical strength and stability of the film. The key to the entire process is to precisely control the formation of the pores through electrospinning and template method, so that the final film not only has excellent conductivity and proton conductivity, but also maintains high performance and stability during long-term cyclic use. The design of this structure and the selection of materials make the film perform well in high-performance energy storage devices, which can significantly improve the overall efficiency and life of the battery.

[0011] In addition, in the present application, the conductive material dispersion is first added to the polyvinylidene fluoride (PVDF) solution, which can make the conductive material fully dispersed in a higher viscosity environment and form a good bond with the matrix. This sequence can ensure that the conductive material is uniformly distributed in the entire PVDF matrix to form a stable conductive network. After the conductive material is uniformly distributed, the addition of the proton-conducting material dispersion helps to avoid interference between the conductive material and the proton-conducting material, thereby ensuring that the proton-conducting material can better fill the gaps in the conductive network. This method helps to form a dual-network structure that does not interfere with each other but works synergistically, thereby improving the overall performance of the material.

[0012] As a preferred technical solution of the preparation method of the solid electrolyte film, the carbon-based nanomaterial is graphene or carbon nanotubes, and the mass ratio of the carbon-based nanomaterial to polyvinylidene fluoride is 1 to 10:100.

[0013] By adopting the above technical solution, the main role of graphene or carbon nanotubes is to significantly improve the comprehensive performance of the solid electrolyte film by forming an efficient conductive network, improving mechanical strength, providing high specific surface area, and promoting ion migration. These characteristics make the film have wide application potential in high-performance energy storage devices, especially in applications requiring dual conductive (electronic and proton) functions, and exhibit superior performance.

[0014] As a preferred technical solution of the preparation method of the solid electrolyte film, the proton-conducting material is zirconium phosphate or molybdenum sulfide, and the mass ratio of the proton-conducting material to polyethylene oxide is 1 to 5:100.

[0015] By adopting the above technical solution, zirconium phosphate and molybdenum sulfide as proton-conducting materials, the main role is to improve the proton conductivity of the film, enhance the overall electrochemical performance, accelerate the proton migration rate, and provide good chemical and structural stability. These characteristics make the film perform well in applications requiring simultaneous electronic and proton conduction.

[0016] As a preferred technical solution of the preparation method of the solid electrolyte film, the voltage is controlled at 10-20kV, the flow rate is controlled at 0.1-1mL / h, and the receiving distance is 10-20cm.

[0017] In this application, the control of voltage, flow rate and receiving distance not only determines the formation of fibers and the basic structure of the film, but also closely related to the generation and optimization of the pore structure. By accurately adjusting these parameters, the uniformity, size and morphology of the pore structure can be optimized, thereby providing efficient ion and electron conduction channels in the film. This optimized pore structure plays an important role in improving the performance of the electrolyte film, making the film have significant advantages in the application of high-performance energy storage devices.

[0018] As a preferred technical solution of the preparation method of the solid electrolyte film, the vacuum drying temperature is controlled at 30℃, and the drying time is 12-24 hours.

[0019] Controlling the vacuum drying temperature at 30℃ and setting the drying time to 12-24 hours can effectively avoid thermal degradation of the material, ensure complete removal of the solvent, maintain the integrity of the nanopore structure, and promote uniform drying of the film. Through this mild and continuous drying process, the finally prepared solid electrolyte film has excellent electrochemical performance and structural stability, and is suitable for application scenarios such as high-performance energy storage devices.

[0020] As a preferred technical solution of the preparation method of the solid electrolyte film, the solidification time is 40℃, and the drying time is 4 to 8 hours.

[0021] The solid electrolyte thin film prepared by the method of the present application has a nano-pore structure formed therein, and the pore diameter of the nano-pore structure is 10 nm to 100 nm. In the present application, by forming a nano-pore structure with a pore diameter of 10 nm to 100 nm, the performance of the electrolyte thin film is significantly improved. The pore structure in this pore diameter range not only optimizes the ion and electron conduction performance of the thin film, but also enhances its mechanical strength, energy storage capacity and thermal management performance.

[0022] As a preferred technical solution of the method for preparing a solid electrolyte thin film, the template material is a polystyrene microsphere template, and the dissolving agent is dichloromethane.

[0023] In the present application, polystyrene microspheres are used as template materials, and dichloromethane is used as a dissolving agent, which plays a key role. The polystyrene microsphere template provides a controllable nano-pore structure, while dichloromethane as a high-efficiency dissolving agent can quickly and completely remove the template material, preserve and optimize the pore structure, and at the same time will not damage the thin film matrix. This combination makes the prepared solid electrolyte thin film have excellent electrochemical performance and mechanical strength, meeting the application requirements of high-performance energy storage devices.

[0024] In addition, the electrolyte thin film prepared by the method for preparing a solid electrolyte thin film of the present application has a nano-pore structure formed therein, and the pore diameter of the nano-pore structure is 10 nm to 100 nm. In the present application, by forming a nano-pore structure with a pore diameter of 10 nm to 100 nm, the performance of the electrolyte thin film is significantly improved. The pore structure in this pore diameter range not only optimizes the ion and electron conduction performance of the thin film, but also enhances its mechanical strength, energy storage capacity and thermal management performance.

[0025] The solid electrolyte thin film of the present application exhibits significant beneficial effects through innovative material design and process optimization. First, by introducing carbon-based nanomaterials (such as graphene or carbon nanotubes) and proton-conducting materials, the thin film realizes dual-ion conduction characteristics of both electrical conductivity and proton conductivity, greatly improving the overall performance of the battery. In addition, the nano-pore structure prepared by electrospinning and template method not only effectively improves the ion mobility and electrical conductivity, but also significantly enhances the mechanical strength of the thin film, prolongs the cycle life of the battery. At the same time, the application of carbon-based nanomaterials in the thin film constructs an efficient conductive network, optimizes the interface stability of the electrolyte and the electrode, reduces the occurrence of side reactions, and thus improves the coulombic efficiency. Finally, the optimized pore size distribution and material ratio enable the electrolyte thin film to maintain excellent electrochemical performance under high current density conditions, making it suitable for various high-performance energy storage devices and having wide application prospects. BRIEF DESCRIPTION OF DRAWINGS

[0026] The accompanying drawings are included to provide a further understanding of the application and are incorporated in and constitute a part of the specification, illustrate embodiments of the application and are used to explain the application, but are not intended to limit the application. In the drawings:

[0027] Figure 1 The pore size distribution of the pores in the electrolyte thin film prepared for Examples 1 to 3;

[0028] Figure 2 The data graph of Example 1 and Comparative Example 1 is shown in Figure 1.

[0029] Figure 3 The data graph of Example 2 and Comparative Example 2 is shown in Figure 2. DETAILED DESCRIPTION

[0030] In order to make the above objectives, features and advantages of the present application more apparent, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0031] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, it will be apparent to one skilled in the art that the present application can be practiced without the specific details given herein, that the present application can be practiced with other than the described embodiments, and that variations from the particular embodiments described herein can be made and still be within the scope of the present application.

[0032] Secondly, the term "one embodiment" or "an embodiment" as used herein means that a particular implementation can include a particular feature, structure, or characteristic, but every embodiment can not necessarily include the particular feature, structure, or characteristic. Furthermore, the following claims can refer to "one embodiment" or "an embodiment" in the sense of claiming a particular feature, structure, or characteristic of more than one embodiment.

[0033] Example 1

[0034] A method for preparing a solid electrolyte thin film, comprising the following technical steps:

[0035] S1. Dissolving polyvinylidene fluoride (PVDF) in an appropriate amount of N,N-dimethylacetamide (DMF) and stirring until completely dissolved to obtain a uniform PVDF solution;

[0036] S2. Dispersing graphene in ethanol and uniformly dispersing using ultrasonic treatment to obtain a conductive material dispersion; wherein the mass ratio of graphene to N,N-dimethylacetamide in step S1 is 1:100;

[0037] S3. Dispersing zirconium phosphate in ethanol and uniformly dispersing by ultrasonic treatment to obtain a proton conductive material dispersion;

[0038] S4. Adding the conductive material dispersion to the PVDF solution and thoroughly stirring to obtain a mixed precursor solution;

[0039] S5. A polystyrene microsphere template was fixed to a fiber receiver in an electrospinning apparatus. The mixed precursor solution was loaded into a syringe in the electrospinning apparatus and electrospun by adjusting the voltage and flow rate to prepare a PVDF fiber membrane containing carbon-based nanomaterials. The voltage was controlled at 20 kV, the flow rate was controlled at 0.5 mL / h, and the receiving distance was controlled at 20 cm.

[0040] S6. A certain proportion of polyethylene oxide (PEO) and a proton-conducting material are dissolved in ethanol to form a second configuration precursor solution, and the second configuration precursor solution is evenly poured on the PVDF fiber membrane and allowed to stand for a period of time to allow it to be fully infiltrated; wherein the mass ratio of the proton-conducting material to the polyethylene oxide is 5:100;

[0041] S7. The cast composite film is cured, and the cured composite film is immersed in a solvent to remove the template material, and then vacuum dried to obtain a dual-ion conductor solid electrolyte film with a nanoporous structure, wherein the curing time is 40°C, the drying time is 8 hours, the vacuum drying temperature is controlled at 30°C, and the drying time is 12 hours.

[0042] Example 2

[0043] A method for preparing a solid electrolyte film comprises the following technical steps:

[0044] S1. Dissolve polyvinylidene fluoride (PVDF) in an appropriate amount of N,N-dimethylacetamide (DMF) and stir until completely dissolved to obtain a uniform PVDF solution;

[0045] S2. The carbon nanotubes are dispersed in ethanol and treated with ultrasound until uniformly dispersed to obtain a conductive material dispersion; wherein the mass ratio of graphene to N,N-dimethylacetamide in step S1 is 10:100;

[0046] S3. Molybdenum sulfide was dispersed in ethanol and uniformly dispersed by ultrasonic treatment to obtain a dispersion of a proton-conducting material;

[0047] S4. The conductive material dispersion is added to the PVDF solution and stirred thoroughly to obtain a mixed precursor solution;

[0048] S5. Fix the polystyrene microsphere template on the fiber receiver of the electrospinning device, and load the mixed precursor solution into the syringe of the electrospinning device. Electrospinning is performed by adjusting the voltage and flow rate to prepare a PVDF fiber membrane containing carbon-based nanomaterials. The voltage is controlled at 10 kV, the flow rate is controlled at 1 mL / h, and the receiving distance is 10 cm.

[0049] S6. A certain proportion of polyethylene oxide (PEO) and proton conductive material are dissolved in ethanol to form a second configuration precursor solution, the second configuration precursor solution is uniformly poured on the PVDF fiber membrane, and is left to stand for a period of time to allow it to be fully infiltrated; wherein the mass ratio of the proton conductive material to the polyethylene oxide is 1:100;

[0050] S7. The poured composite membrane is subjected to curing treatment, the cured composite membrane is immersed in a dissolving agent to remove the template material, and then vacuum drying treatment is performed to obtain a solid electrolyte thin film of a dual-ion conductor with a nano-pore structure, wherein the curing time is 40°C, the drying time is 8 hours, the vacuum drying temperature is controlled at 30°C, and the drying time is 24 hours.

[0051] Example 3

[0052] A preparation method of a solid electrolyte thin film, comprising the following technical steps:

[0053] S1. Polyvinylidene fluoride (PVDF) is dissolved in an appropriate amount of N,N-dimethylacetamide (DMF) and stirred until completely dissolved to obtain a uniform PVDF solution;

[0054] S2. Graphene is dispersed in ethanol and uniformly dispersed by ultrasonic treatment to obtain a conductive material dispersion liquid; wherein the mass ratio of the graphene to the N,N-dimethylacetamide in step S1 is 5:100;

[0055] S3. Molybdenum sulfide is dispersed in ethanol and uniformly dispersed by ultrasonic treatment to obtain a proton conductive material dispersion liquid;

[0056] S4. The conductive material dispersion liquid is added to the PVDF solution and stirred thoroughly to obtain a mixed precursor solution;

[0057] S5. The polystyrene microsphere template is fixed on the fiber receiver of the electrospinning device, and the mixed precursor solution is loaded into the syringe of the electrospinning device, electrospinning is performed by adjusting the voltage and flow rate, and a PVDF fiber membrane containing carbon-based nanomaterials is prepared; wherein the voltage is controlled at 15kV, the flow rate is controlled at 0.1mL / h, and the receiving distance is 15cm;

[0058] S6. A certain proportion of polyethylene oxide (PEO) and proton conductive material are dissolved in ethanol to form a second configuration precursor solution, the second configuration precursor solution is uniformly poured on the PVDF fiber membrane, and is left to stand for a period of time to allow it to be fully infiltrated; wherein the mass ratio of the proton conductive material to the polyethylene oxide is 1:100;

[0059] S7. The cast composite film is subjected to a curing process, and after the curing process, the composite film is immersed in a dissolving agent to remove the template material, and then subjected to a vacuum drying process to obtain a solid electrolyte thin film of a dual-ion conductor with a nano-pore structure, wherein the curing time is 40°C, the drying time is 8 hours, the vacuum drying temperature is controlled at 30°C, and the drying time is 24 hours.

[0060] Comparative Example 1

[0061] The difference between this comparative example and Example 1 is that in step S5, the polystyrene microsphere template is not fixed on the fiber receiver of the electrospinning device, and there is no need for the dissolving agent in the subsequent step S7 to remove the template.

[0062] Comparative Example 2

[0063] The difference between this comparative example and Example 2 is that in step S3, polyethylene oxide (PEO) is dissolved in ethanol to form a second configuration precursor solution, which is uniformly cast on the PVDF fiber film and allowed to stand for a period of time to allow it to fully soak.

[0064] Application Example 1

[0065] Battery assembly steps: LiCoO2 is selected as the positive electrode material, and graphite is selected as the negative electrode material. The solid electrolyte materials prepared in Examples 1 to 3 and Comparative Examples 1 and 2 are placed between the positive and negative electrodes as the electrolyte separator of the battery. The specific assembly process is carried out in a glove box to prevent the influence of air and moisture on the battery materials. The positive electrode, electrolyte material, and negative electrode are assembled into a battery using a pressing or winding process.

[0066] Performance testing

[0067] Pore size analysis of the electrolyte material: nitrogen adsorption-desorption method (BET / BJH) measures the amount of nitrogen adsorbed by the material at different pressures to calculate the parameters of the pore structure.

[0068] Constant current charge and discharge test: the assembled battery is connected to a battery testing instrument to perform multiple charge and discharge cycles at a set current density (0.1C to 2C), and the voltage, current, and time data of the battery are recorded.

[0069] Examples 1 to 3 and Figure 1It can be seen that the pore size distribution of Example 1 is mainly concentrated in the range of 30 to 70 nanometers, the pore size distribution of Example 2 is mainly concentrated in the range of 10 to 50 nanometers, and the pore size distribution of Example 3 ranges from 40 to 100 nanometers. The nanometer pore size has a key influence on the performance of the electrolyte. First, the nanoscale pore size can significantly increase the specific surface area of the electrolyte, which helps to improve the ion mobility and conductivity. The nanometer pore size provides a shorter ion conduction path, enabling ions to pass through the electrolyte more quickly, thereby improving the power density of the battery. In addition, the presence of nanometer pore size can form a larger interfacial contact area between the electrolyte and the electrode, enhance the interfacial compatibility, effectively reduce the interfacial impedance, and improve the electrochemical performance of the battery.

[0070] In combination with Example 1, Comparative Example 1, and Figure 2 It can be seen that the capacity retention of Example 1 remains at a high level during the 8000 cycles, always above 99%, and the downward trend is relatively slow, which indicates that the electrolyte material in Example 1 has good stability and durability during long-term cycling; in contrast, the capacity retention of Comparative Example 1 decreases rapidly, from nearly 100% initially to about 97%, and the downward trend is obvious, which indicates that the electrolyte material in Comparative Example 1 has a more significant performance degradation during long-term cycling; the coulombic efficiency of Example 1 remains at about 98% during the entire cycle, showing extremely high energy efficiency, which indicates that the electrolyte material in Example 1 can effectively suppress the occurrence of side reactions, reduce energy loss, and ensure the efficient operation of the battery; the coulombic efficiency of Comparative Example 1 is relatively low, remaining at about 97%, and the lower coulombic efficiency indicates that the electrochemical stability of the electrolyte material in Comparative Example 1 is relatively poor, and more side reactions may occur, leading to increased energy loss; the pore structure provides an efficient ion migration channel, enabling ions in the electrolyte to move quickly and smoothly, which helps to reduce the internal resistance of the electrolyte and reduce energy loss during charging and discharging, thereby improving the coulombic efficiency; the pore structure not only optimizes ion migration but also forms a more stable interfacial contact between the electrolyte and the electrode, reducing side reactions such as electrolyte decomposition or electrode material corrosion between the electrolyte and the electrode, which can greatly improve the coulombic efficiency and maintain a high capacity retention rate during long-term cycling.

[0071] In combination with Example 2, Comparative Example 2, and Figure 3It can be seen that the capacity retention of Example 2 remains at a high level during the 8000 cycles, always above 99%, and the downward trend is relatively slow, which indicates that the electrolyte material in Example 2 has good stability and durability during long-term cycling; in contrast, the capacity retention of Comparative Example 2 decreases rapidly, from nearly 100% initially to about 97%, and the downward trend is obvious, which shows that the electrolyte material in Comparative Example 2 has a significant performance degradation during long-term cycling; the coulomb efficiency of Example 2 remains at about 98.5% during the entire cycle process, showing extremely high energy efficiency, which indicates that the electrolyte material in Example 2 can effectively suppress the occurrence of side reactions, reduce energy loss, and ensure the efficient operation of the battery; the coulomb efficiency of Comparative Example 2 is relatively low, remaining at about 96%, and the lower coulomb efficiency indicates that the electrochemical stability of the electrolyte material in Comparative Example 2 is relatively poor, and more side reactions may occur, leading to increased energy loss; the proton-conducting material (such as zirconium phosphate or molybdenum sulfide) has good proton conductivity, and it can provide efficient proton conduction channels in the electrolyte film. This efficient proton conductivity forms a synergistic effect with the electronic conductivity in the electrolyte, allowing the battery to efficiently conduct protons and electrons during charging and discharging, reducing internal resistance and thus improving coulomb efficiency. In addition, efficient proton conduction can also ensure that the electrolyte maintains a high ion mobility during long-term cycling, reducing capacity decay; the proton material not only effectively conducts protons, but also forms a stable interfacial layer between the electrolyte and the electrode, suppressing the occurrence of side reactions. The stable interfacial layer reduces the corrosion of the electrode material and the decomposition of the electrolyte, thereby improving the coulomb efficiency. The stability of the proton-conducting material is particularly important in long-term use, as it can prevent rapid degradation of the electrolyte film, allowing the capacity retention to remain at a high level after 8000 cycles.

[0072] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can modify the technical solutions described in the foregoing embodiments or make equivalent replacements of some technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for producing a solid electrolyte thin film, characterized by, The technical steps include the following steps: Dissolve polyvinylidene fluoride (PVDF) in an appropriate amount of N,N-dimethylacetamide (DMF) and stir until completely dissolved to obtain a uniform PVDF solution; Disperse the carbon-based nanomaterial in ethanol and uniformly disperse using ultrasonic treatment to obtain a conductive material dispersion; Disperse the proton-conducting material in ethanol and uniformly disperse by ultrasonic treatment to obtain a proton-conducting material dispersion; Add the conductive material dispersion to the PVDF solution and stir thoroughly to obtain a mixed precursor solution; Fix the template material on the fiber receiver of the electrospinning device and load the mixed precursor solution into the syringe of the electrospinning device, adjust the voltage and flow rate, and perform electrospinning to prepare a PVDF fiber membrane containing carbon-based nanomaterials; Dissolve a certain proportion of polyethylene oxide (PEO) and proton-conducting material in ethanol to form a second configuration precursor solution, uniformly pour the second configuration precursor solution onto the PVDF fiber membrane, and stand for a period of time to allow it to fully soak; Perform curing treatment on the poured composite membrane, immerse the cured composite film in a dissolving agent to remove the template material, and then perform vacuum drying treatment to obtain a double-ion conductor solid electrolyte film with a nano-pore structure; The carbon-based nanomaterial is graphene or carbon nanotubes, and the mass ratio of the carbon-based nanomaterial to polyvinylidene fluoride is 1 to 10:

100. The proton-conducting material is zirconium phosphate or molybdenum sulfide, and the mass ratio of the proton-conducting material to polyethylene oxide is 1 to 5:

100.

2. The method for producing a solid electrolyte thin film according to claim 1, characterized by, The voltage is controlled at 10-20 kV, the flow rate is controlled at 0.1-1 mL / h, and the receiving distance is 10-20 cm.

3. The method for producing a solid electrolyte thin film according to claim 1, characterized by, The vacuum drying temperature is controlled at 30°C, and the drying time is 12-24 hours.

4. The method for producing a solid electrolyte thin film according to claim 1, characterized by, The curing time is 40°C, and the drying time is 8 hours.

5. The method of producing a solid electrolyte thin film according to claim 1, characterized by, The template material is a polystyrene microsphere template, and the dissolving agent is dichloromethane.

6. The electrolyte film prepared based on the method for preparing a solid electrolyte film according to any one of claims 1 to 5, characterized by The electrolyte film forms a nano-pore structure, and the pore size of the nano-pore structure is 10 nm to 100 nm.

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