Preparation method of sulfide electrolyte film of all-solid-state battery
By composite coating of interface-modified slurry and electrolyte functional slurry and hot-pressing ultraviolet irradiation treatment, the interfacial compatibility and compactness problems of sulfide electrolyte films were solved, realizing the efficient preparation of high-performance all-solid-state battery films, which are suitable for mass production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- DONGGUAN LILONG BATTERY TECH CO LTD
- Filing Date
- 2026-02-09
- Publication Date
- 2026-05-08
AI Technical Summary
In the existing technology, sulfide electrolyte films have poor interfacial compatibility, and gaps are easily generated between the electrolyte layer and the substrate and electrodes, resulting in high ion transport impedance. Furthermore, the existing coating process is difficult to achieve uniform composite of the modification layer and the electrolyte layer, the film thickness is poorly controllable, and it cannot effectively suppress lithium dendrite penetration. The process is complex, the production efficiency is low, and it is difficult to adapt to large-scale production.
A composite coating method using interface-modified slurry and electrolyte functional slurry, combined with simultaneous treatment of microgravure coating, hot pressing and ultraviolet irradiation, is adopted to form in-situ crosslinking and densification, thus preparing a sulfide electrolyte film. The synergistic effect of fast ion conductor, polymer elastomer and crosslinkable binder is utilized to improve interface compatibility and densification.
It achieves tight interface bonding, high ion conduction efficiency, and excellent thin-film mechanical properties, significantly improving the cycle stability, rate performance, and safety of all-solid-state batteries, making it suitable for mass production.
Smart Images
Figure CN122000442A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of battery technology, specifically to a method for preparing a sulfide electrolyte thin film for an all-solid-state battery. Background Technology
[0002] Solid-state batteries have become a core research and development direction in the new energy field due to the absence of safety hazards such as leakage and explosion associated with liquid electrolytes, and their significantly superior energy density and cycle stability compared to traditional liquid batteries. Sulfide electrolytes, with their high lithium-ion mobility and low electronic conductivity, are key materials for preparing high-performance solid-state batteries, and the quality of their thin film preparation directly determines the overall performance of the battery.
[0003] Currently, there are many technical bottlenecks in the preparation of sulfide electrolyte films: poor interfacial compatibility, gaps easily form between the electrolyte layer and the substrate and electrodes, resulting in high ion transport impedance; existing coating processes are difficult to achieve uniform composite of the modification layer and the electrolyte layer, and the film thickness is poorly controllable; crosslinking and densification are carried out in multiple steps, which easily leads to problems such as loose interfacial bonding, film springback, and excessive porosity, and cannot effectively suppress lithium dendrite penetration; moreover, the process is complex and the production efficiency is low, making it difficult to adapt to large-scale production. Summary of the Invention
[0004] To overcome the shortcomings of existing technologies, this invention provides a method for preparing sulfide electrolyte films for all-solid-state batteries, which can effectively solve the problems raised in the background technology.
[0005] The technical solution adopted by this invention to solve its technical problem is:
[0006] A method for preparing a sulfide electrolyte thin film for an all-solid-state battery includes the following steps:
[0007] Step S1, preparing interface-modified slurry: mixing interface modifier with a first solvent to obtain interface-modified slurry; the interface modifier includes fast ion conductor and polymer elastomer;
[0008] Step S2, preparing electrolyte functional slurry: Mix sulfide electrolyte, binder and second solvent to obtain electrolyte functional slurry;
[0009] Step S3, Composite Coating: First, the interface modification slurry is coated on the substrate to form a modification layer, and then the electrolyte functional slurry is coated on the modification layer to form an electrolyte layer, thus obtaining a composite wet film;
[0010] Step S4, in-situ crosslinking and densification treatment: The composite wet film is subjected to simultaneous hot pressing and ultraviolet irradiation treatment, so that the modified layer and the electrolyte layer undergo in-situ crosslinking at the interface and densification to form a sulfide electrolyte film.
[0011] As a further description of the above technical solution, in step S1, the fast ion conductor is at least one of lithium lanthanum zirconium oxide, lithium lanthanum titanium oxide, or lithium nitride; the polymer elastomer is at least one of polyurethane, polybutadiene, or styrene-butadiene-styrene block copolymer.
[0012] As a further description of the above technical solution, in step S1, the interface-modified slurry further includes a photoinitiator, which is at least one of benzoin dimethyl ether, 2-hydroxy-2-methyl-1-phenyl-1-propanone, or 1-hydroxycyclohexylphenyl ketone.
[0013] As a further description of the above technical solution, in step S3, a microgravure coating method is used for coating, the wet film thickness of the modified layer is 1-5 μm, and the wet film thickness of the electrolyte layer is 10-50 μm.
[0014] As a further description of the above technical solution, in step S4, the temperature of the hot pressing treatment is 60-100℃, the pressure is 10-50MPa, and the time is 1-10 minutes; the wavelength of the ultraviolet light irradiation is 320-400nm, and the light intensity is 50-200mW / cm².
[0015] As a further description of the above technical solution, in step S2, the adhesive is a crosslinkable adhesive containing carbon-carbon double bonds, which is at least one of modified styrene-butadiene rubber, modified polyacrylate, or ethylene-vinyl acetate copolymer.
[0016] As a further description of the above technical solution, the modified styrene-butadiene rubber is a styrene-butadiene rubber grafted with maleic anhydride.
[0017] As a further description of the above technical solution, after step S4, the method further includes: step S5, peeling and winding: peeling the sulfide electrolyte film from the substrate and winding it up.
[0018] Compared with the prior art, the beneficial effects of the present invention are:
[0019] The present invention provides a method for preparing a sulfide electrolyte thin film for an all-solid-state battery, which has at least one of the following beneficial effects during use:
[0020] During the preparation process, an interface modifier composed of fast ion conductors and polymer elastomers, combined with a specific photoinitiator, can improve interfacial compatibility, reduce ion transport impedance, alleviate interfacial stress, and reduce interfacial side reactions. A microgravure coating process is used to precisely control the film thickness, balancing ion conduction efficiency and film mechanical properties, ensuring coating uniformity. Simultaneous hot pressing and UV irradiation are used in synergistic treatment to achieve in-situ crosslinking and densification, completely solving the problem of loose interfacial bonding, effectively inhibiting lithium dendrite penetration, and protecting the stability of sulfide electrolytes. Crosslinkable binders and maleic anhydride-grafted modified styrene-butadiene rubber further optimize the crosslinking effect and ion conduction network, and the peeling and winding process is suitable for large-scale production. The resulting film exhibits excellent performance; when applied to all-solid-state batteries, it can reduce polarization loss, significantly improve battery cycle stability, rate performance, and safety, and promote the industrialization of all-solid-state batteries. Attached Figure Description
[0021] Figure 1 This is a flowchart illustrating the preparation method of a sulfide electrolyte thin film for an all-solid-state battery according to the present invention.
[0022] Figure 2 This is a schematic diagram of the sizing composition in step S1 of the method for preparing a sulfide electrolyte thin film for an all-solid-state battery according to the present invention.
[0023] Figure 3 This is a flowchart of step S3, composite coating process, of a method for preparing a sulfide electrolyte film for an all-solid-state battery according to the present invention. Detailed Implementation
[0024] 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.
[0025] like Figure 1-3 As shown, this invention provides a method for preparing a sulfide electrolyte thin film for an all-solid-state battery, comprising the following steps:
[0026] Step S1, preparing interface-modified slurry: mixing interface modifier with a first solvent to obtain interface-modified slurry; the interface modifier includes fast ion conductor and polymer elastomer;
[0027] Fast ion conductors, acting as "bridges" for ion conduction, possess high lithium-ion migration rates, effectively reducing the ion transport impedance of the modified layer and preventing it from becoming a bottleneck for lithium-ion conduction. Furthermore, these fast ion conductors exhibit good chemical compatibility with sulfide electrolytes and electrode materials (such as ternary cathode materials and silicon-based anode materials), reducing the occurrence of chemical reactions at the interface and minimizing the formation of interfacial byproducts.
[0028] Polymer elastomers, acting as interfacial "buffers," possess excellent flexibility and adhesion, capable of filling minute defects on the substrate surface, enabling the modified layer to form a tightly bonded interface with the substrate and reducing interfacial gaps. Simultaneously, the flexible characteristics of polymer elastomers can alleviate interfacial stresses generated during subsequent hot pressing, ultraviolet irradiation, and battery charging and discharging, preventing interfacial cracking and improving the mechanical stability of the film.
[0029] By combining photoinitiators as "triggers" for subsequent in-situ crosslinking, they can rapidly decompose under ultraviolet light of a specific wavelength (320-400nm), generating active free radicals, providing active sites for the interfacial crosslinking reaction between the modified layer and the electrolyte layer, and ensuring that the crosslinking reaction occurs efficiently and in a controllable manner.
[0030] Step S2, preparing electrolyte functional slurry: Mix sulfide electrolyte, binder and second solvent to obtain electrolyte functional slurry;
[0031] As the core of ion conduction in the entire thin film, sulfide electrolyte has a lithium-ion mobility much higher than that of oxide electrolyte, which is the key to achieving high ion conduction efficiency in all-solid-state batteries. At the same time, sulfide electrolyte has extremely low electronic conductivity, which can effectively prevent self-discharge inside the battery and improve the cycle stability and safety of the battery.
[0032] The binder serves two purposes: firstly, it acts as a binder, tightly binding the sulfide electrolyte particles together to ensure a continuous and complete electrolyte layer after subsequent coating; secondly, the carbon-carbon double bonds in the binder can undergo cross-linking reactions with the active groups of the polymer elastomer in the modification layer under ultraviolet light, achieving interfacial fusion between the modification layer and the electrolyte layer and further enhancing the interfacial bonding force.
[0033] The second solvent, acting as a dispersion medium, serves to uniformly disperse the sulfide electrolyte particles and binder, forming a slurry with suitable fluidity. This ensures that the slurry can be evenly spread during subsequent coating processes, avoiding problems such as particle agglomeration and uneven coating, thus guaranteeing the preparation of an electrolyte layer with uniform thickness.
[0034] Step S3, Composite Coating: First, the interface modification slurry is coated on the substrate to form a modification layer, and then the electrolyte functional slurry is coated on the modification layer to form an electrolyte layer, thus obtaining a composite wet film;
[0035] First, a modification layer is applied, which allows the modification layer to fully bond with the substrate and form a stable transition interface. Then, an electrolyte functional slurry is applied to the modification layer. At this time, the active groups on the surface of the modification layer (such as hydroxyl groups and double bonds of polymer elastomers) can be initially adsorbed with the active groups of the binder in the electrolyte layer, which lays the groundwork for the subsequent in-situ crosslinking reaction and avoids problems such as poor interfacial compatibility and difficulty in peeling caused by direct contact between the electrolyte layer and the substrate.
[0036] Microgravure coating features high coating precision and strong thickness control, allowing for precise control of the wet film thickness of the modification layer (1-5μm) and the electrolyte layer (10-50μm). The relatively thin modification layer avoids hindering ion conduction while ensuring interface buffering. The moderate electrolyte layer thickness satisfies the requirements for ion conduction while also considering the film's flexibility and the battery's energy density (excessive thickness reduces battery energy density, while excessive thinness affects compactness and mechanical stability).
[0037] Step S4, in-situ crosslinking and densification treatment: The composite wet film is subjected to simultaneous hot pressing and ultraviolet irradiation treatment, so that the modified layer and the electrolyte layer undergo in-situ crosslinking at the interface and densification to form a sulfide electrolyte film.
[0038] Under ultraviolet light with a wavelength of 320-400 nm and an intensity of 50-200 mW / cm², the photoinitiator in the modification layer decomposes to generate active free radicals, which trigger a cross-linking reaction between the active groups (such as double bonds) of the polymer elastomer in the modification layer and the carbon-carbon double bonds of the cross-linkable binder in the electrolyte layer, forming a three-dimensional cross-linked network structure. This cross-linking reaction occurs at the interface between the modification layer and the electrolyte layer, achieving "molecular-level fusion" between the two, completely solving the problem of weak interfacial bonding and easy peeling between the two layers in traditional layered coating. At the same time, the cross-linked network can fix ion conduction channels and improve the stability of ion conduction.
[0039] At temperatures of 60-100℃ and pressures of 10-50MPa, hot pressing allows the first and second solvents in the composite wet film to evaporate rapidly, preventing excessively high film porosity caused by solvent residue. Simultaneously, hot pressing promotes the compact packing of sulfide electrolyte particles, reducing internal porosity and improving film density. This density enhances the inhibition of lithium dendrite growth during the charging and discharging process of all-solid-state batteries (lithium dendrites can pierce the electrolyte film, causing short circuits and posing safety hazards). Furthermore, suitable hot pressing temperatures soften the polymer elastomer and binder, promoting cross-linking reactions while preventing excessively high temperatures from causing sulfide electrolyte decomposition (sulfide electrolytes readily react with oxygen and moisture at high temperatures, reducing ion conductivity).
[0040] Hot pressing and ultraviolet irradiation are carried out simultaneously, rather than in separate steps. This avoids the problems that occur in separate steps, such as "the film becomes hard after cross-linking and is difficult to densify" or "the interfacial gap is too large after densification, resulting in poor cross-linking effect". The synergistic effect of the two can achieve efficient densification of the film while ensuring sufficient cross-linking of the interface, taking into account interfacial compatibility, ion conduction efficiency and mechanical stability.
[0041] Furthermore, in step S1, the fast ion conductor is at least one of lithium lanthanum zirconium oxide, lithium lanthanum titanium oxide, or lithium nitride; the polymer elastomer is at least one of polyurethane, polybutadiene, or styrene-butadiene-styrene block copolymer.
[0042] Inorganic fast ion conductors possess excellent high lithium-ion conductivity and chemical stability, and are highly compatible with the lithium-ion conduction mechanism of sulfide electrolytes. They can form continuous and efficient ion conduction channels in the modified layer, significantly reducing the interfacial ion transport impedance between the modified layer and the electrolyte layer, and between the substrate / electrode, thus solving the problem of low ion conduction efficiency of traditional modifiers.
[0043] Polymer elastomers possess excellent flexibility, elasticity, and film-forming properties, and do not undergo any chemical side reactions with sulfide electrolytes or fast ion conductors. They can not only encapsulate fast ion conductors to form a uniform and dense modification layer, but also alleviate interfacial stress generated during subsequent hot pressing and battery charging and discharging, preventing the modification layer from cracking and peeling off, while improving the interfacial adhesion between the modification layer and the subsequent electrolyte layer.
[0044] Furthermore, in step S1, the interface-modified slurry also includes a photoinitiator, which is at least one of benzoin dimethyl ether, 2-hydroxy-2-methyl-1-phenyl-1-propanone, or 1-hydroxycyclohexylphenyl ketone.
[0045] The photoinitiator exhibits extremely high response efficiency to 320-400nm ultraviolet light. Under ultraviolet irradiation, it rapidly decomposes to generate free radicals, efficiently triggering in-situ crosslinking reactions between the polymer elastomer in the modified layer and the crosslinkable binder in the electrolyte layer. This significantly improves the rate and uniformity of the crosslinking reaction, avoiding problems such as insufficient crosslinking and loose interfacial bonding. The selected photoinitiator is chemically stable and does not undergo side reactions with components such as sulfide electrolytes, fast ion conductors, and polymer elastomers. Furthermore, it leaves no harmful residues after the crosslinking reaction, does not contaminate the film, and does not block ion conduction channels, ensuring that the ion conduction performance of the sulfide electrolyte film remains unaffected.
[0046] Furthermore, in step S3, a microgravure coating method is used for coating, the wet film thickness of the modified layer is 1-5 μm, and the wet film thickness of the electrolyte layer is 10-50 μm.
[0047] The composite coating process using microgravure coating has the advantages of fast coating speed, high film thickness uniformity, and no pinholes or bubbles in the coating. It can ensure that the modification layer and electrolyte layer are evenly spread on the substrate, avoiding problems such as uneven coating and excessive local thickness differences. It effectively improves the consistency of the overall film performance and solves the defects of local ion conduction obstruction and insufficient density caused by traditional coating methods.
[0048] The wet film thickness of the modified layer is limited to 1-5 μm. This thickness can fully utilize the "transition effect" of the modified layer, effectively isolate the sulfide electrolyte from the substrate / electrode and avoid interfacial side reactions, and also avoid the increase in ion transport impedance caused by excessively thick modified layers.
[0049] The wet film thickness of the electrolyte layer is limited to 10-50μm. This thickness ensures that the electrolyte layer has sufficient ion conduction capacity and good mechanical support properties, which can not only achieve efficient lithium-ion conduction, but also effectively block the electronic conduction between the positive and negative electrodes of the battery and lithium dendrite penetration. At the same time, it avoids the decrease in the overall ion conductivity of the film and the reduction in battery energy density caused by excessive electrolyte layer thickness, thus balancing performance and practicality.
[0050] Furthermore, the hot pressing treatment is carried out at a temperature of 60-100℃, a pressure of 10-50MPa, and a time of 1-10 minutes; the ultraviolet light irradiation has a wavelength of 320-400nm and an intensity of 50-200mW / cm².
[0051] The hot-pressing parameters are limited to 60-100℃, 10-50MPa, and 1-10 minutes. The 60-100℃ range is a medium-low temperature range, which can quickly evaporate the first and second solvents in the composite wet film, while avoiding the decomposition of sulfide electrolytes and side reactions between the modified layer and the electrolyte layer caused by high temperature, thus protecting the chemical stability of each component. The pressure of 10-50MPa can fully reduce the molecular gaps in the composite wet film, achieving full densification of the film and improving its barrier properties. The processing time of 1-10 minutes can balance solvent evaporation efficiency, densification effect, and production efficiency, avoiding insufficient densification and solvent residue due to too short a time, and reduced production efficiency and deterioration of film performance due to too long a time.
[0052] The ultraviolet irradiation parameters are limited to 320-400nm and 50-200mW / cm². The wavelength of 320-400nm is precisely matched with the absorption wavelength of the selected photoinitiator, which can maximize the response efficiency of the photoinitiator and ensure that the interfacial crosslinking reaction is sufficient and uniform. The irradiation intensity of 50-200mW / cm² can precisely control the rate of crosslinking reaction, avoiding insufficient crosslinking and weak interfacial bonding due to too low intensity, and excessively high intensity leading to local crosslinking and stress cracking of the film, thus ensuring the integrity of the film structure.
[0053] Furthermore, in step S2, the adhesive is a crosslinkable adhesive containing carbon-carbon double bonds, which is at least one of modified styrene-butadiene rubber, modified polyacrylate, or ethylene-vinyl acetate copolymer.
[0054] A crosslinkable binder containing carbon-carbon double bonds is selected. Under ultraviolet light, these double bonds can undergo a crosslinking reaction with the active groups of the polymer elastomer in the modified layer, significantly enhancing the interfacial bonding between the two layers. Self-crosslinking can occur within the electrolyte layer, forming a three-dimensional network structure. This effectively encapsulates sulfide electrolyte particles, improving the mechanical strength and structural stability of the electrolyte layer itself, preventing cracking and detachment. It also provides a continuous channel for lithium-ion conduction, avoiding an increase in ion conduction impedance caused by excessive binder coating.
[0055] It should be further noted that the modified styrene-butadiene rubber is a styrene-butadiene rubber grafted with maleic anhydride.
[0056] Maleic anhydride-grafted styrene-butadiene rubber (SBR) introduces maleic anhydride active groups through a grafting reaction. Compared with unmodified SBR, its reactivity with polymer elastomers and photoinitiators in the modified layer is significantly enhanced. This can further accelerate the rate of interfacial crosslinking reaction, improve the sufficiency and uniformity of the crosslinking reaction, make the interfacial bonding between the modified layer and the electrolyte layer tighter, and further reduce the interfacial ion transport impedance.
[0057] Maleic anhydride grafting modification can significantly improve the compatibility between styrene-butadiene rubber and sulfide electrolyte particles, reduce the interfacial gap between the binder and the sulfide electrolyte, avoid problems such as uneven binder coating and electrolyte particle agglomeration, ensure the formation of a continuous ion conduction network inside the electrolyte layer, and further improve the ionic conductivity of the film.
[0058] Furthermore, after step S4, the following steps are also included:
[0059] Step S5, Peeling and winding: Peel the sulfide electrolyte film from the substrate and wind it up.
[0060] Separation of the film from the substrate facilitates subsequent large-scale applications. After in-situ crosslinking and densification, the film exhibits good mechanical strength and flexibility, and can be separated from the substrate through a gentle peeling process (such as mechanical peeling). The winding process can organize the film into a roll, which facilitates subsequent processes such as lamination with electrodes and cutting, thereby improving the continuity of the preparation process and the efficiency of large-scale production.
[0061] The sulfide electrolyte film forms an integrated structure of modification layer and electrolyte layer. The modification layer realizes interface buffering and ion conduction transition, while the electrolyte layer realizes efficient ion conduction. The cross-linked network enhances the interfacial bonding force and mechanical stability, and the dense structure inhibits lithium dendrite growth. Ultimately, it has high ion conductivity, good interfacial compatibility, high density and excellent mechanical stability.
[0062] An all-solid-state battery includes a sulfide electrolyte film. The sulfide electrolyte film, used as an ion-conducting medium, is sandwiched between the positive and negative electrodes. The film's high ion conductivity improves the battery's rate performance and cycle stability, its density enhances safety, and its good interfacial compatibility reduces internal interfacial impedance and polarization losses, ultimately achieving high performance, high safety, and long lifespan for the all-solid-state battery.
[0063] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.
Claims
1. A method for preparing a sulfide electrolyte thin film for an all-solid-state battery, characterized in that, Includes the following steps: Step S1, preparing interface-modified slurry: mixing interface modifier with a first solvent to obtain interface-modified slurry; the interface modifier includes fast ion conductor and polymer elastomer; Step S2, preparing electrolyte functional slurry: Mix sulfide electrolyte, binder and second solvent to obtain electrolyte functional slurry; Step S3, Composite Coating: First, the interface modification slurry is coated on the substrate to form a modification layer, and then the electrolyte functional slurry is coated on the modification layer to form an electrolyte layer, thus obtaining a composite wet film; Step S4, in-situ crosslinking and densification treatment: The composite wet film is subjected to simultaneous hot pressing and ultraviolet irradiation treatment, so that the modified layer and the electrolyte layer undergo in-situ crosslinking at the interface and densification to form a sulfide electrolyte film.
2. The method for preparing a sulfide electrolyte thin film for an all-solid-state battery according to claim 1, characterized in that: In step S1, the fast ion conductor is at least one of lithium lanthanum zirconium oxide, lithium lanthanum titanium oxide, or lithium nitride; the polymer elastomer is at least one of polyurethane, polybutadiene, or styrene-butadiene-styrene block copolymer.
3. The method for preparing a sulfide electrolyte thin film for an all-solid-state battery according to claim 1, characterized in that: In step S1, the interface-modified slurry further includes a photoinitiator, which is at least one of benzoin dimethyl ether, 2-hydroxy-2-methyl-1-phenyl-1-propanone, or 1-hydroxycyclohexylphenyl ketone.
4. The method for preparing a sulfide electrolyte thin film for an all-solid-state battery according to claim 1, characterized in that: In step S3, a microgravure coating method is used for coating, the wet film thickness of the modified layer is 1-5 μm, and the wet film thickness of the electrolyte layer is 10-50 μm.
5. The method for preparing a sulfide electrolyte thin film for an all-solid-state battery according to claim 1, characterized in that: In step S4, the hot pressing treatment is performed at a temperature of 60-100℃, a pressure of 10-50MPa, and a time of 1-10 minutes; the ultraviolet light irradiation is performed at a wavelength of 320-400nm and an intensity of 50-200mW / cm².
6. A method for preparing a sulfide electrolyte thin film for an all-solid-state battery according to any one of claims 1 to 5, characterized in that: In step S2, the adhesive is a crosslinkable adhesive containing carbon-carbon double bonds, which is at least one of modified styrene-butadiene rubber, modified polyacrylate, or ethylene-vinyl acetate copolymer.
7. The method for preparing a sulfide electrolyte thin film for an all-solid-state battery according to claim 6, characterized in that: The modified styrene-butadiene rubber is a styrene-butadiene rubber grafted with maleic anhydride.
8. The preparation method according to any one of claims 1 to 5, characterized in that: After step S4, the method further includes step S5, peeling and winding: peeling the sulfide electrolyte film from the substrate and winding it up.