Skeleton support solid electrolyte membrane and preparation method and application thereof

Abstract

This invention provides a skeleton-supported solid electrolyte membrane, its preparation method, and its application. The skeleton-supported solid electrolyte membrane includes at least a skeleton support material, a binder, and a solid electrolyte. The skeleton-supported solid electrolyte membrane has good mechanical properties, which can improve the flexibility and mechanical strength of the solid electrolyte membrane, reduce the influence of silicon anode stress, and effectively solve the solid-solid interface contact problem. This is conducive to achieving longer cycle life and higher power density, thereby gradually realizing the low-cost and mass application of high-energy-density solid-state batteries.

Description

Technical Field

[0001] This invention relates to the field of solid electrolyte technology, and in particular to a solid electrolyte membrane with an introduced skeleton support material, its preparation method and application. Background Technology

[0002] Solid-state batteries use solid electrolytes instead of traditional liquid electrolytes, which can significantly improve battery safety, energy density, and performance stability. Among them, sulfide solid electrolytes, as a type of solid electrolyte, have advantages such as high room temperature ionic conductivity and high electrochemical stability, which help to further improve the energy density and cycle life of solid-state batteries.

[0003] Generally speaking, sulfide solid electrolyte membranes are brittle and prone to cracking, and they easily react with positive electrode materials, leading to problems such as increased interfacial impedance, which limits the cycle performance of the battery.

[0004] In the existing technology, the integrated production process of coating solid electrolyte on a support structure and directly rolling up and down the solid electrolyte membrane reduces the cost of large-scale production of solid electrolyte membrane and obtains electrolyte membrane with controllable thickness. However, the mechanical strength and toughness of the solid electrolyte membrane still cannot meet the safety requirements of solid lithium-ion batteries, which raises concerns about the electrochemical stability and interface impedance of the solid-solid interface between the solid electrolyte and the cathode material. Summary of the Invention

[0005] This invention provides a skeleton-supported solid electrolyte membrane, its preparation method, and its application. It can improve the mechanical strength of the solid electrolyte membrane, reduce the impact of silicon anode stress, and effectively reduce the internal resistance of solid-state batteries, thereby reducing battery costs and manufacturing processes. This is conducive to achieving longer cycle life and higher power density, thus gradually realizing the low-cost and mass application of high-energy-density solid-state batteries.

[0006] One embodiment of the present invention provides a skeleton-supported solid electrolyte membrane, which includes at least: a skeleton support material; a solid electrolyte in the pores of the skeleton support material; and an adhesive in the pores of the skeleton support material, wherein the median particle size d of the solid electrolyte is smaller than the pore size D1 of the skeleton support material and larger than the pore size D2 of the solid electrolyte membrane.

[0007] In some embodiments, the median particle size d, the pore size D1, and the pore size D2 satisfy the relationship: 20 < (D1 - D2) / d < 200.

[0008] In some embodiments, the framework-supported solid electrolyte membrane includes one or more of the following features: the median particle size d is 0.1 μm to 3.0 μm; the pore size D1 is 40 μm to 100 μm; and the pore size D2 is 50 nm to 300 nm.

[0009] In some embodiments, the skeleton-supported solid electrolyte membrane comprises 1 to 5 parts by weight of the skeleton support material, 90 to 94 parts by weight of the solid electrolyte, and 1 to 5 parts by weight of the binder.

[0010] In some embodiments, the framework-supported solid electrolyte membrane includes one or more of the following characteristics: the porosity of the framework support material is 60% to 90%; the thickness of the framework support material is 5 μm to 30 μm; and the basis weight of the framework support material is 1 g / m³. 2 Up to 10 g / m 2 .

[0011] In some embodiments, the solid electrolyte includes a sulfide solid electrolyte.

[0012] In some embodiments, the adhesive comprises one or more of polymethyl methacrylate, polyacrylate, acrylate-styrene copolymer, thermoplastic elastomer, polyisobutylene, styrene-butadiene rubber, polyvinylidene fluoride, thermoplastic styrene-butadiene rubber, synthetic rubber, hydrogenated nitrile rubber, cis-butadiene rubber, or nitrile rubber, and the tensile strength of the adhesive is from 20 MPa to 50 MPa.

[0013] In some embodiments, the skeleton support material includes one of nanofiber membranes, nonwoven fabrics, fishing nets, microporous nylon membranes, microporous polyimide (PI) membranes, microporous polyethylene (PE) membranes, microporous polypropylene (PP) membranes, woven fabrics, nylon filter membranes, polytetrafluoroethylene (PTFE) filter membranes, polypropylene (PP) filter membranes, and polyethersulfone (PES) filter membranes.

[0014] In some embodiments, one or more of the following features are included: The bending radius of the skeleton supporting the solid electrolyte membrane is, for example, less than or equal to 3 mm; The longitudinal tensile strength of the skeleton supporting the solid electrolyte membrane is 15.0 MPa to 30.0 MPa, and the longitudinal elongation at break is 14% to 20%. The skeletal support for the solid electrolyte membrane has a transverse tensile strength of 14.0 MPa to 30.0 MPa and a transverse elongation at break of 9% to 20%. The ionic conductivity of the solid electrolyte membrane supported by the skeleton is greater than or equal to 1.0 mS / cm. The electronic conductivity of the solid electrolyte membrane supported by the framework is 2.4 × 10⁻⁶. -10 S / cm up to 3.2×10 -10 S / cm; The thickness of the solid electrolyte membrane supported by the skeleton is less than or equal to 30 μm; The porosity of the solid electrolyte membrane supported by the skeleton is less than or equal to 10%.

[0015] Another embodiment of the present invention provides a method for preparing a framework-supported solid electrolyte membrane, which includes at least the following steps: Slurry preparation steps: Mix the binder and solid electrolyte evenly to obtain the slurry; Fixing steps: Fix the skeleton support material onto the base film to obtain the skeleton support base film; Coating and film formation step: The slurry is coated on the skeleton support base film, and then heated to form a skeleton electrolyte film on the base film by the binder, the solid electrolyte and the skeleton support material; Separation steps: separating the skeleton electrolyte membrane and the base membrane; and Hot pressing step: The skeleton electrolyte membrane is subjected to hot pressing treatment to obtain a skeleton-supported solid electrolyte membrane.

[0016] In some embodiments, prior to mixing the binder and the solid electrolyte, the slurry preparation step further includes: uniformly mixing the binder and the solvent, wherein the solvent includes one or more of isobutyl isobutyrate, anisole, cyclopentyl methyl ether, isopentane, n-pentane, cyclohexane, isooctane, cyclopentane, n-hexane, n-heptane, toluene, or xylene; and / or the base film is a release film or an inorganic base film.

[0017] In some embodiments, the temperature of the heat treatment is 50°C to 100°C; and / or the duration of the heat treatment is 2 hours to 12 hours.

[0018] In some embodiments, the separation step further includes: applying a preset pressure to the skeleton electrolyte membrane and the base membrane along the thickness direction of the base membrane until the skeleton electrolyte membrane separates from the base membrane, wherein the preset pressure is less than the pressure of the hot pressing treatment.

[0019] In some embodiments, the temperature for hot-pressing the electrolyte membrane is 50°C to 100°C; and / or the pressure for hot-pressing the electrolyte membrane is 50 MPa to 100 MPa; and / or the time for hot-pressing the electrolyte membrane is 2 hours to 12 hours.

[0020] Another embodiment of the present invention provides a solid-state battery, which includes at least: a positive electrode; a negative electrode; and a skeleton-supported solid electrolyte membrane disposed between the positive electrode and the negative electrode, wherein the skeleton-supported solid electrolyte membrane is the skeleton-supported solid electrolyte membrane as described above or the skeleton-supported solid electrolyte membrane obtained by the preparation method described above.

[0021] This invention provides a framework-supported solid electrolyte membrane, its preparation method, and its applications. By introducing a framework support material, the mechanical properties of the solid electrolyte membrane are improved, the interfacial contact between the electrode and the solid electrolyte membrane is enhanced, the battery capacity retention rate is increased, and the battery's energy density and cycle life are improved. Furthermore, the framework-supported solid electrolyte membrane provided by this invention fills all the pores of the solid electrolyte membrane, reducing its porosity. The framework support material also provides strong support and rigidity, which not only improves the mechanical properties of the electrolyte membrane and effectively prevents short circuits caused by cracks due to negative electrode volume expansion, but also improves the contact between the solid electrolyte membrane and the positive and negative electrode sheets, suppressing lithium dendrite formation. Further, the porous framework support material filling the solid electrolyte membrane structure significantly reduces the membrane's porosity, ensuring uniform lithium-ion flux, thereby reducing ion transport heterogeneity and suppressing uneven lithium deposition. All these effects contribute to improving battery energy density and cycle life, accelerating the low-cost and mass production of high-energy-density solid-state batteries. Attached Figure Description

[0022] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0023] In the attached diagram: Figure 1 The flowchart illustrates the preparation process of the skeleton-supported solid electrolyte membrane provided by this invention.

[0024] Figure 2 The first charge-discharge curve of the solid electrolyte membrane assembled battery with skeleton support in Example 2 is shown.

[0025] Figure 3 The cycling curves are for the solid electrolyte membrane assembly battery with a skeleton support in Example 2. Detailed Implementation

[0026] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0027] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0028] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the invention. However, it will be apparent to those skilled in the art that embodiments of the invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the invention.

[0029] A first embodiment of the present invention provides a skeleton-supported solid electrolyte membrane, comprising at least a solid electrolyte, a binder, and a skeleton support material, wherein the solid electrolyte is located in the pores of the skeleton support material, the binder is located in the pores of the skeleton support material, and the median particle size d of the solid electrolyte is smaller than the pore size D1 of the skeleton support material and larger than the pore size D2 of the solid electrolyte membrane.

[0030] Understandably, the solid electrolyte particles are bonded to each other through a binder, or to the surface of the support material through a binder; in other words, the solid electrolyte and binder are not confined to the pores of the support material, but can also be distributed on the surface of the support structure that defines these pores; the solid electrolyte and binder carried by the solvent are coated onto the support material, and accumulate in the pores of the support material through capillary or pore permeation, reducing the pore size D1 of the support material to pore size D2; because the support material is flexible, the pore size D2 can be dynamically changed by bending and folding, thereby changing the electronic and ion conductivity of the solid electrolyte membrane supported by the support material.

[0031] In some embodiments, the median particle size d, the pore size D1, and the pore size D2 satisfy the relationship: 20 < (D1 - D2) / d < 200, preferably 22 < (D1 - D2) / d < 150, and more preferably 22 < (D1 - D2) / d < 50.

[0032] In this invention, the solid electrolyte is in the form of powder, for example, with a median particle size d of, for example, 0.1 μm to 3.0 μm, preferably 0.5 μm to 3.0 μm, and more preferably 1.8 μm to 3.0 μm. By controlling the median particle size of the solid electrolyte, the contact area between the solid electrolyte powders can be increased, the grain boundary resistance can be reduced, a more continuous transport channel for lithium ions can be provided, and the ionic conductivity can be improved. Understandably, the term "median particle size" in this invention refers to the 50% particle size in the cumulative particle size distribution based on volume.

[0033] In some embodiments, the pore size D1 is 40 μm to 100 μm, preferably 40 μm to 50 μm, 45 μm to 55 μm or 70 μm to 100 μm, more preferably 40 μm to 50 μm or 90 μm to 100 μm.

[0034] In some embodiments, the aperture D2 is 50 nm to 300 nm, preferably 60 nm to 75 nm, 100 nm to 200 nm or 160 nm to 300 nm, more preferably 160 nm to 200 nm or 200 nm to 300 nm.

[0035] In some embodiments, the skeleton-supported solid electrolyte membrane comprises 1 to 5 parts by weight of the skeleton support material, 90 to 94 parts by weight of the solid electrolyte, and 1 to 5 parts by weight of the binder; in a preferred embodiment, the skeleton-supported solid electrolyte membrane comprises 4 to 5 parts by weight of the skeleton support material, 91 to 93 parts by weight of the solid electrolyte, and 2 to 3 parts by weight of the binder.

[0036] In some embodiments, the solid electrolyte may be, for example, a sulfide solid electrolyte, such as Li. 10 GeP2S 12 Li6PS5Cl, Li6PS5Br, or Li3. 25 Ge0. 25 At least one of P0.7S4, etc.

[0037] In some embodiments, the porosity of the skeleton support material is 60% to 90%, preferably 70% to 90%.

[0038] In some embodiments, the thickness of the skeleton support material is 5 μm to 30 μm, preferably 10 μm to 20 μm.

[0039] In some embodiments, the basis weight of the skeleton support material is 1 g / m³.2 Up to 10 g / m 2 Preferably 2g / m 2 Up to 5g / m 2 .

[0040] In these embodiments, the skeleton support material includes one of the following: nanofiber membrane, nonwoven fabric, fishing net, microporous nylon membrane, microporous polyimide (PI) membrane, microporous polyethylene (PE) membrane, microporous polypropylene (PP) membrane, woven fabric, nylon filter membrane, polytetrafluoroethylene (PTFE) filter membrane, polypropylene (PP) filter membrane, and polyethersulfone (PES) filter membrane; preferably, the skeleton support material includes nanofiber membrane, nonwoven fabric, or microporous nylon membrane.

[0041] In several embodiments, the adhesive includes one or more of polymethyl methacrylate, polyacrylate, acrylate-styrene copolymer, thermoplastic elastomer, polyisobutylene, styrene-butadiene rubber, polyvinylidene fluoride, thermoplastic styrene-butadiene rubber, synthetic rubber, hydrogenated nitrile rubber, cis-butadiene rubber, or nitrile rubber.

[0042] In some embodiments, the adhesive is preferably a thermoplastic elastomer, which may be a styrenic block copolymer (SBC) elastomer, a thermoplastic polyolefin (TPO) elastomer, a thermoplastic polyurethane (TPU) elastomer, a thermoplastic polyester (TPC) elastomer, a thermoplastic polyamide (TPA) elastomer, a thermoplastic vulcanizate (TPV) elastomer, a thermoplastic plastic (TP) elastomer, or a high-performance engineering plastic (HPEP).

[0043] In these embodiments, non-limiting examples of the SBC may be styrene-butadiene-styrene copolymer (SBS) or styrene-ethylene-butadiene-styrene copolymer (SEBS); In these embodiments, a non-limiting example of the TPO may be a polypropylene / ethylene propylene diene copolymer (PP / EPDM).

[0044] In these embodiments, non-limiting examples of the TP may be polybutylene terephthalate (PBT), polystyrene (PS), polyethylene terephthalate (PET), or polycarbonate (PC).

[0045] In these embodiments, non-limiting examples of the HPEP may be polyamide (PA), polyoxymethylene (POM), polyphenylene sulfide (PPS), polyethyleneimine (PEI), polyetheretherketone (PEEK), and liquid crystal polymer (LCP).

[0046] In these embodiments, the tensile strength of the adhesive is between 20 MPa and 50 MPa. By limiting the tensile strength of the adhesive, the structural integrity and deformation resistance of the solid electrolyte membrane can be balanced, avoiding insufficient tensile strength that could lead to membrane rupture, while also preventing excessive tensile strength that could reduce the deformation capacity of the solid electrolyte membrane and cause interfacial mismatch between the electrode and the solid electrolyte membrane. In this embodiment, the bending radius of the skeleton supporting the solid electrolyte membrane is, for example, less than or equal to 3 mm, specifically, 0.01 mm, 1 mm, 2 mm or 3 mm and any value between them, specifically, 0.1 mm, 0.2 mm...2.9 mm, etc. The introduction of the skeleton support material improves the flexibility and bending strength of the solid electrolyte membrane. The flexible solid electrolyte membrane can fill the microstructure of the electrode surface through elastic deformation, thereby reducing the voids between the electrolyte membrane and the electrode interface, preventing crack propagation, reducing interface impedance, increasing the ion conduction rate of the solid electrolyte membrane, significantly reducing the battery internal resistance, increasing the utilization rate of the positive and negative electrode active materials, weakening battery polarization, and extending the battery cycle life.

[0047] In this embodiment, the longitudinal tensile strength of the skeleton-supported solid electrolyte membrane is, for example, 15.0 MPa to 30.0 MPa, and the transverse tensile strength is, for example, 14.0 MPa to 30.0 MPa, specifically, 14.0 MPa, 15.0 MPa, 20.0 MPa, 25.0 MPa, 30.0 MPa, or any value between these values. Introducing the skeleton support material improves the mechanical strength of the solid electrolyte membrane, helps improve the interfacial contact between the electrode and the solid electrolyte membrane, increases the cycle life of the battery, and enhances the battery's energy density and safety.

[0048] In this embodiment, the longitudinal elongation at break of the skeleton-supported solid electrolyte membrane is, for example, 14% to 20%, and the transverse elongation at break is, for example, 9% to 20%. Controlling the elongation at break can balance the mechanical strength and flexibility of the solid electrolyte membrane, avoiding the problem of cracking caused by too low an elongation at break, or the problem of insufficient mechanical strength caused by too high an elongation at break.

[0049] In this embodiment, the ionic conductivity of the skeleton-supported solid electrolyte membrane is, for example, greater than or equal to 1.0 mS / cm, which reduces ion transport impedance, optimizes interfacial ion transport between the solid electrolyte membrane and the electrode, reduces interfacial impedance, and improves the cycle life of the battery.

[0050] In this embodiment, the electronic conductivity of the framework-supported solid electrolyte membrane is, for example, 2.4 × 10⁻⁶. -10 S / cm up to 3.2×10 -10 S / cm can block electronic short-circuit paths, improve battery safety, suppress side reactions between solid electrolyte and electrodes, maintain the stability of the interface between solid electrolyte membrane and electrodes, and improve battery cycle life and performance stability.

[0051] In this embodiment, the thickness of the skeleton supporting the solid electrolyte membrane is, for example, less than or equal to 30 μm, and the porosity of the solid electrolyte membrane is, for example, less than or equal to 10%, specifically, 1%, 3%, 4%, 5%, 7%, 8%, 9%, 10%, or any value between these values; by controlling the porosity of the solid electrolyte membrane, the continuity of the ion channel can be enhanced and the conductivity efficiency can be improved.

[0052] Please see Figure 1 The second embodiment of the present invention also provides a method for preparing a skeleton-supported solid electrolyte membrane, which includes at least the following steps:

[0053] Slurry preparation step S1: Uniformly mix the binder and solid electrolyte to obtain the slurry; Step S2: Fix the skeleton support material onto the base film to obtain the skeleton support base film; Coating and film formation step S3: The slurry is coated on the skeleton support base film and then heated to form a skeleton electrolyte film on the base film by the binder, the solid electrolyte and the skeleton support material; Separation step S4: Separating the skeleton electrolyte membrane and the base membrane; and Hot pressing step S5: The skeleton electrolyte membrane is subjected to hot pressing treatment to obtain a skeleton-supported solid electrolyte membrane.

[0054] In this embodiment, before mixing the binder and the solid electrolyte, the slurry preparation step S1 further includes: uniformly mixing the binder and the solvent. First, the binder and solvent are stirred and mixed to obtain a mixed solution. Then, the mixed solution is heated to a preset temperature and held at that temperature for a preset time to ensure that the binder and solvent are fully and uniformly mixed. After standing to remove bubbles, a binder solution is obtained. The solvent may include, for example, one or more of isobutyl isobutyrate, anisole, cyclopentyl methyl ether, isopentane, n-pentane, cyclohexane, isooctane, cyclopentane, n-hexane, n-heptane, toluene, or xylene. The preset temperature is, for example, 80°C to 90°C, and the preset time is, for example, 12 hours to 48 hours.

[0055] In this embodiment, in the slurry preparation step S1, the binder solution and solid electrolyte are placed in a degassing machine and stirred until homogeneous, then filtered and defoamed to obtain the slurry. The degassing machine operates at, for example, 1200 rpm to 3200 rpm, and the stirring time is, for example, 10 minutes to 60 minutes.

[0056] In this embodiment, in the coating and film-forming step S3, for example, after uniformly coating the slurry onto the skeleton support base film using a flat plate coating machine, the slurry-skeleton support base film is transferred to a heating table for heating and drying treatment, so that the solids in the slurry, namely the solid electrolyte and binder, form a skeleton electrolyte film on the base film.

[0057] In this embodiment, the base film can be, for example, a release film or an inorganic base film. Non-limiting examples of release films include polyethylene terephthalate (PET) release film, polyethylene (PE) release film, polypropylene (PP) release film, polyvinyl chloride (PVC) release film, polycarbonate (PC) release film, etc. Non-limiting examples of inorganic base films include alumina ceramic base film, silicon dioxide base film, or silicon nitride base film, etc.

[0058] In this embodiment, the temperature of the heat treatment is, for example, 50°C to 100°C, preferably 80°C; the heat treatment time is, for example, 2 hours to 12 hours, preferably 12 hours.

[0059] In this embodiment, after the skeleton electrolyte membrane is formed on the base membrane, in the separation step S4, the skeleton electrolyte membrane and the base membrane can be separated by methods such as mechanical peeling, solvent swelling, temperature control, or pressure difference separation. In a preferred embodiment, mechanical peeling is used for separation. Specifically, a preset pressure is applied to the skeleton electrolyte membrane and the base membrane along the thickness direction of the base membrane. For example, a roller press is used to apply a preset pressure to the skeleton electrolyte membrane until the skeleton electrolyte membrane and the base membrane are separated. The preset pressure is, for example, 50 MPa to 100 MPa. Preferably, the preset pressure is less than the pressure of the hot pressing treatment, for example, 55 MPa to 75 MPa, and more preferably 60 MPa.

[0060] In this embodiment, in the hot pressing step S5, the hot pressing process can be performed by placing the skeleton electrolyte membrane on a press and hot pressing the skeleton electrolyte membrane. The temperature of the hot pressing process is, for example, 60°C to 100°C, preferably 80°C; the pressure of the hot pressing process is, for example, 50 MPa to 100 MPa, preferably 70 MPa to 90 MPa, more preferably 80 MPa; and the time of the hot pressing process is, for example, 2 hours to 12 hours, preferably 2 hours.

[0061] The types and basic physical parameters of the skeleton support material, solid electrolyte, and binder involved in this embodiment, as well as the basic physical properties of the skeleton support solid electrolyte membrane, such as bending radius, longitudinal tensile strength, transverse elongation at break, ionic conductivity, electronic conductivity, thickness, or porosity, are all detailed in the first embodiment and will not be elaborated upon here.

[0062] Based on the above-mentioned skeleton-supported solid electrolyte membrane and its preparation method, the third embodiment of the present invention also provides a solid battery, such as a primary battery or a secondary battery. The secondary battery is, for example, a pouch battery, a hard-shell battery, or a cylindrical battery. The present invention does not impose specific limitations on the types and categories of solid batteries.

[0063] In a specific embodiment, the solid-state battery includes at least a positive electrode, a negative electrode, and a skeleton-supported solid electrolyte membrane. The skeleton-supported solid electrolyte membrane is disposed between the positive electrode and the negative electrode, and the solid electrolyte membrane is, for example, the skeleton-supported solid electrolyte membrane described above or the skeleton-supported solid electrolyte membrane obtained according to the above preparation method, which will not be elaborated further here.

[0064] In this embodiment, the positive electrode sheet includes, for example, a positive active layer, which includes, for example, a positive active material, a positive electrolyte, a positive conductive agent, and a positive binder. The present invention does not limit the mass ratio of the positive active material, positive electrolyte, positive conductive agent, and positive binder, and these ratios can be selected according to actual needs. In other embodiments of the present invention, in addition to the positive active layer, the positive electrode sheet may also include a positive current collector, with the positive active layer coated on at least one side of the current collector. The positive current collector may be, for example, a foil formed by surface treatment of nickel, titanium, aluminum, silver, stainless steel, or carbon. Besides foil, the positive current collector may also be used in any one or more combinations of various forms such as film, mesh, porous, foam, or non-woven fabric.

[0065] In this embodiment, the positive electrode active material in the positive electrode active layer can be, for example, lithium nickel cobalt manganese oxide (NCM), lithium nickel oxide (LNO), lithium manganese oxide (LMO), lithium nickel manganese oxide (LNMO), lithium cobalt oxide (LCO), or lithium nickel cobalt aluminum oxide (NCA); the positive electrode electrolyte can be, for example, a sulfide solid electrolyte; the positive electrode conductive agent can be, for example, graphite, graphene, conductive carbon black (Super P), vapor-grown carbon fiber (VGCF), or carbon nanotubes; and the positive electrode binder can be, for example, polyvinylidene fluoride (PVDF), carboxymethyl cellulose (CMC), polymerized styrene-butadiene rubber (SBR), polyvinyl pyrrolidone (PVP), polymethyl methacrylate (PMMA), polyacrylonitrile (PAN), or polyacrylic acid. Sodium alginate (Alg), polyurethane, polyvinyl alcohol (PVA), ethylene-propylene-diene monomer, styrene-butadiene rubber, fluororubber, β-cyclodextrin polymer (β-CDp), polypropylene emulsion (LA132), polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene copolymer (ETFE), fluorinated ethylene-propylene copolymer (FEP), perfluoroalkoxy resin (PFA), polychlorotrifluoroethylene (PCTFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE), polyvinylidene fluoride-hexafluoropropylene copolymer or polyvinylidene fluoride-trifluorochloroethylene copolymer.

[0066] In this embodiment, the positive electrode active material is, for example, LiNi. 0.8 Co 0.1 Mn 0.1O2, the positive electrode electrolyte is, for example, the solid electrolyte provided by the present invention, the positive electrode conductive agent includes, for example, Super P and VGCF, and the mass ratio of Super P and VGCF is, for example, 1:1, and the positive electrode binder is, for example, PTFE. After the positive electrode active material, positive electrode electrolyte, positive electrode conductive agent and positive electrode binder are mixed evenly in a mass ratio of, for example, 69:29:1:1, the positive electrode sheet is directly obtained by dry pressing.

[0067] In this embodiment, the positive current collector is, for example, aluminum foil, and the positive active material is, for example, LiNi. 0.8 Co 0.1 Mn 0.1 O2, positive electrode electrolyte such as Li6PS5Cl, positive electrode conductive agent such as Super P and VGCF, with a mass ratio of Super P to VGCF of 1:1, and binder such as PTFE. The positive electrode active material, positive electrode electrolyte, positive electrode conductive agent, and positive electrode binder are mixed evenly in a mass ratio of 69:29:1:1, and then rolled onto the surface of aluminum foil to obtain the positive electrode sheet.

[0068] In this embodiment, the negative electrode may be, for example, a silicon wafer, a lithium metal wafer, an indium metal wafer, or a lithium-indium alloy wafer.

[0069] In this embodiment, the aforementioned positive electrode, solid electrolyte membrane, and negative electrode are sequentially stacked, packaged, and pressurized to assemble a solid-state battery. The assembly process of the solid-state battery is completed in a glove box with an inert atmosphere.

[0070] The present invention will be explained in more detail below by referring to embodiments, which should not be construed as limiting. Appropriate modifications can be made within the scope of the present invention, and all such modifications fall within the technical scope of the present invention.

[0071] Example 1

[0072] Preparation of Solid Electrolyte Membranes Slurry preparation steps: The binder SEBS and solvent anisole were stirred to obtain a mixed solution. This solution was then heated to 80°C and held at that temperature for 24 hours. After standing and defoaming, a binder solution was obtained. Next, the binder solution and solid electrolyte Li6PS5Cl were placed in a defoamer and stirred until homogeneous at 2000 rpm for 20 minutes. After filtration and defoaming, a slurry was obtained, wherein the median particle size d of the solid electrolyte Li6PS5Cl was 0.5 μm.

[0073] Fixing step: Fix the skeleton support material onto the base film with adhesive to obtain the skeleton support base film. The skeleton support material is a non-woven fabric with a thickness of 10 μm, a porosity of 90%, and a pore size D1 of 70 μm. Coating and film formation steps: After uniformly coating the slurry onto the skeleton support base film using a flat plate coating machine, the slurry-skeleton support base film is transferred to a heating table for heating treatment. The heating temperature is 80℃ and the heating time is 12 hours, so that the solids in the slurry can form a skeleton electrolyte film together with the skeleton support material on the skeleton support base film. Separation steps: Using a roller press, apply a pressure of 60 MPa to the skeleton electrolyte membrane-base membrane until the skeleton electrolyte membrane separates from the base membrane; and Hot pressing step: The skeleton electrolyte membrane is placed on a hot press and a pressure of 80 MPa is applied. It is kept at 80°C for 2 hours to obtain a skeleton-supported solid electrolyte membrane. The binder accounts for 2.85 wt%, the solid electrolyte accounts for 92.15 wt%, the skeleton support material accounts for 5 wt%, the pore size D2 of the skeleton-supported solid electrolyte membrane is 100 nm, and the porosity is 7.6%.

[0074] Preparation of Positive Electrode Sheets LiNi 0.8 Co 0.1 Mn 0.1 O2 positive electrode active material, solid electrolyte Li6PS5Cl, positive electrode conductive agent and PTFE are mixed evenly in a mass ratio of 69:29:1:1, and then the positive electrode sheet is obtained by dry pressing. The positive electrode conductive agent includes Super P and VGCF, and the mass ratio of Super P and VGCF is, for example, 1:1.

[0075] The Choice of Negative Electrode Film Silicon wafers were chosen as the negative electrode.

[0076] Solid-state battery fabrication After cutting the positive electrode, negative electrode, and solid electrolyte membrane into circular pieces with a diameter of 10 mm, they were placed in a polyether ether ketone (PEEK) mold. The framework supports the solid electrolyte membrane located between the positive and negative electrode pieces, thus obtaining the initial mold battery. Then, the PEEK mold was held at 350 MPa for 2 minutes to obtain the final battery structure as NCM811|Li6PS5Cl|Si.

[0077] Example 2

[0078] The difference from Example 1 is that the porosity of the skeleton support material is 80% and the pore size D1 is 55 μm.

[0079] Example 3

[0080] The difference from Example 1 is that the porosity of the skeleton support material is 70% and the pore size D1 is 45 μm.

[0081] Example 4

[0082] The difference from Example 1 is that the thickness of the skeleton support material is 20 μm, the porosity is 90%, and the pore size D1 is 100 μm.

[0083] Example 5

[0084] The difference from Example 4 is that the thickness of the skeleton support material is 20 μm, the porosity is 80%, and the pore size D1 is 50 μm.

[0085] Example 6

[0086] The difference from Example 4 is that the thickness of the skeleton support material is 20 μm, the porosity is 70%, and the pore size D1 is 40 μm.

[0087] Comparative Example 1 The difference from Example 1 is that the thickness of the skeleton support material is 10 μm, the porosity is 90%, and the pore size D1 is 0.5 μm.

[0088] Comparative Example 2 The difference from Example 1 is that the thickness of the skeleton support material is 10 μm, the porosity is 80%, and the pore size D1 is 0.1 μm.

[0089] Comparative Example 3 The difference from Example 1 is that the thickness of the skeleton support material is 10 μm, the porosity is 90%, and the pore size D1 is 110 μm.

[0090] Comparative Example 4 The difference from Example 1 is that the thickness of the skeleton support material is 10 μm, the porosity is 80%, and the pore size D1 is 20 μm.

[0091] Comparative Example 5 The difference from Example 1 is that there is no frame support material.

[0092] Comparative Example 6 The difference from Example 1 is that the porosity of the skeleton support material is 60%.

[0093] Comparative Example 7 The difference from Example 1 is that: a flatbed coating machine is used to directly and uniformly coat the slurry onto the skeleton support material to obtain a slurry-skeleton support material composite; then, the aforementioned composite is transferred to a heating table for heating and drying treatment, and then wound up to obtain a skeleton support electrolyte membrane.

[0094] Comparative Example 8 The difference from Example 6 is that, in the separation step, the skeletal electrolyte membrane is removed from the base membrane using a solvent swelling method.

[0095] Comparative Example 9 The difference from Example 1 is that the skeleton support material uses a nanofiber membrane with a pore size D1 of 110 μm.

[0096] The differences between the framework-supported solid electrolyte membranes prepared in each embodiment and comparative example are summarized in Table 1.

[0097] Table 1. Differences in the preparation of solid electrolyte membranes in Examples 1-6 and Comparative Examples 1-9

[0098] In this invention, the performance of the solid electrolyte membranes in Examples 1-6 and Comparative Examples 1-5, as well as solid batteries prepared using different solid electrolyte membranes, was tested, and the test results are shown in Table 2.

[0099] Please refer to Table 2. The present invention determines the porosity of solid electrolyte membranes by mercury intrusion porosimetry, which is briefly described as follows: In a mercury intrusion porosimeter, the solid electrolyte membrane is gradually pressurized from a low pressure of 0.1 kPa to a high pressure of 200 MPa, so that mercury penetrates into the pores of the solid electrolyte membrane under pressure. The pore size is calculated from the pressure according to the Washburn equation. By recording the mercury penetration volume and subtracting the dead volume, the porosity is finally calculated as the ratio of the mercury penetration volume to the apparent volume of the sample.

[0100] Please refer to Table 2. The present invention determines the ionic conductivity of a solid electrolyte membrane using AC impedance spectroscopy, briefly described as follows: After coating both sides of the solid electrolyte membrane with silver paste and drying it, it is placed in the test fixture of an electrochemical workstation, such as a Gamry Reference 620, forming an "electrode-electrolyte-electrode" sandwich structure. Then, at 5 × 10⁻⁶... 6 Hz to 10 -1 A sinusoidal AC signal scan at Hz was used to collect impedance data, which was then plotted as a Nyquist plot. The electrolyte bulk resistance R was obtained through equivalent circuit fitting. b Then, combining the sample thickness L and the electrode area A, the ionic conductivity is calculated using the formula: Ionic conductivity = L / (R b ×A).

[0101] Please refer to Table 2. The present invention measures the electronic conductivity of a solid electrolyte membrane by a DC polarization method, which is briefly described as follows: Silver paste is coated on both sides of the solid electrolyte membrane and dried to form an "electrode-electrolyte-electrode" sandwich structure. The membrane is then connected to an electrochemical workstation, such as a Gamry Reference 620, and a DC voltage is applied at 30°C. The current value under steady-state conditions is measured, the sample resistance is calculated based on Ohm's law, and the electronic conductivity is obtained by combining the sample thickness and the electrode area.

[0102] Please refer to Table 2. The tensile strength of the solid electrolyte membrane in this invention is determined using a universal testing machine (Shanghai Xiangjie Instrument Technology Co., Ltd.). A brief description is as follows: An axial tensile force is applied to the skeleton-supported solid electrolyte membrane at a constant rate of 1 mm / min, and the tensile force-displacement curve is recorded simultaneously until the skeleton-supported solid electrolyte membrane breaks. The maximum force value in the recorded force-displacement curve is divided by the cross-sectional area of ​​the skeleton-supported solid electrolyte membrane to obtain the tensile strength. The tensile strength measured along the electrolyte membrane coating direction is the longitudinal tensile strength, and the corresponding elongation at break is the longitudinal elongation at break. The tensile strength measured perpendicular to the electrolyte membrane coating direction is the transverse tensile strength, and the corresponding elongation at break is the transverse elongation at break.

[0103] Please refer to Table 2. The present invention measures the bending radius of the skeleton-supported solid electrolyte membrane using a bending tester, which is briefly described as follows: The skeleton-supported solid electrolyte membrane is fixed on the support device of the tester, such as the QTY-32 paint film cylindrical bending tester. The membrane is bent by applying pressure at a constant rate through the indenter. The deformation is monitored by a displacement sensor. The test is stopped when cracks or breaks appear in the skeleton-supported solid electrolyte membrane. The displacement of the indenter and the position of the force are recorded. The bending radius is calculated or read based on the geometric parameters of the tester and the deformation relationship.

[0104] Please refer to Table 2. The present invention uses a universal mechanical testing machine (Shanghai Xiangjie Instrument Technology Co., Ltd.) to determine the elongation at break of the solid electrolyte membrane. The method is briefly described as follows: The initial length of the solid electrolyte membrane supported by the skeleton is tested, and then an axial tensile force is applied to the solid electrolyte membrane supported by the skeleton at a constant rate of 1 mm / min until it breaks. The testing machine records the displacement change during the tensile process, that is, the extension of the length of the solid electrolyte membrane supported by the skeleton, and calculates the elongation at break according to the formula: Elongation at break = (length at break - initial length) * 100% / initial length.

[0105] Table 2 shows the test results of solid electrolyte membranes and solid batteries in Examples 1-6 and Comparative Examples 1-9.

[0106] Please refer to Tables 1 and 2. Comparing Examples 1 to 6 and Comparative Examples 1 to 5 and 9, it can be seen that when (D1-D2) / d is controlled between 20 and 200, regardless of whether nonwoven fabric, nanofiber membrane, or microporous nylon membrane is used as the skeleton support material, the porosity of the skeleton-supported solid electrolyte membrane is less than 10%, the ionic conductivity is ≥1.2 mS / cm, and the electronic conductivity is within 2.4 × 10⁻⁶ mS / cm. -10 S / cm up to 3.2×10 -10 Within the range of S / cm, the longitudinal tensile strength is ≥15.0 MPa, the longitudinal elongation at break is within the range of 14% to 20%, the transverse tensile strength is within the range of 14.0 MPa to 30.0 MPa, the transverse elongation at break is within the range of 9% to 20%, and the bending radius is less than or equal to 3 mm. All performance characteristics are far superior to those of Comparative Example 5 without a skeleton support material, thus indicating that the introduction of a skeleton support material can change the porosity, ionic conductivity, electronic conductivity, bending radius, tensile strength, and elongation at break of the solid electrolyte membrane.

[0107] Please refer to Tables 1 and 2. Comparing Examples 1 to 6 with Comparative Examples 1 to 4, it can be seen that by controlling (D1-D2) / d between 20 and 200, the porosity of the skeleton-supported solid electrolyte membrane can be controlled below 10%, the ionic conductivity reaches above 1.2 mS / cm, the longitudinal tensile strength is at least 15.6 MPa, the longitudinal elongation at break is in the range of 14% to 20%, the transverse tensile strength is at least 14.1 MPa, the transverse elongation at break is in the range of 9.5% to 20%, and the bending radius is less than or equal to 3 mm and can be controlled below 2.5 mm. The overall performance of Examples 1 to 6 is better than that of Comparative Examples 1 to 4, thus showing that controlling the range of (D1-D2) / d can change the porosity, ionic conductivity, electronic conductivity, bending radius, tensile strength, and elongation at break of the solid electrolyte membrane, thereby significantly improving its overall electrical conductivity and mechanical toughness.

[0108] Please refer to Tables 1 and 2. Comparing Examples 1 and 4, Examples 2 and 5, and Examples 3 and 6, it can be seen that when the thickness of the skeleton support material is 10 μm, the porosity of the skeleton-supported solid electrolyte membrane is less than or equal to 9.0%, the ionic conductivity is greater than or equal to 1.2 mS / cm, and the electronic conductivity is within 2.4 × 10⁻⁶ mS / cm. -10 S / cm up to 3.2×10 -10Within the range of S / cm, the longitudinal tensile strength is in the range of 17.0 MPa-30.0 MPa, the longitudinal elongation at break is in the range of 15.0% to 20.0%, the transverse tensile strength is in the range of 15.0 MPa to 30.0 MPa, the transverse elongation at break is in the range of 10.0% to 20.0%, and the bending radius is less than or equal to 3 mm. This indicates that changing the thickness of the skeleton support material can change the porosity, ionic conductivity, electronic conductivity, bending radius, tensile strength, and elongation at break of the solid electrolyte membrane.

[0109] Please refer to Tables 1 and 2. Comparing Examples 1 and 4 with Examples 2, 3, 5, and 6, it can be seen that when the porosity of the framework support material is increased to 90%, the porosity of the solid electrolyte membrane is still less than or equal to 9.0%, the ionic conductivity reaches above 1.3 mS / cm, and the electronic conductivity reaches at least 2.4 × 10⁻⁶. -10 The tensile strength (S / cm) and longitudinal tensile strength are both within the range of 17.0 MPa to 30.0 MPa, the longitudinal elongation at break is within the range of 15% to 20%, the transverse tensile strength is both within the range of 15.0 MPa to 30.0 MPa, the transverse elongation at break is both within the range of 10% to 20%, and the bending radius is less than or equal to 3 mm. This indicates that limiting the porosity of the skeleton layer can change the porosity, ionic conductivity, electronic conductivity, tensile strength, bending radius, and elongation at break of the solid electrolyte membrane, thereby reducing the battery impedance and improving the battery's energy density and cycle life.

[0110] Please refer to Tables 1 and 2. Comparing Example 1 with Comparative Examples 7 and 8, it can be seen that regardless of whether the slurry is directly and uniformly coated onto the skeleton support material and then directly wound up, or whether the demolding is performed by solvent swelling and roll pressing to obtain the skeleton-supported solid electrolyte membrane, its porosity is still significantly lower than that of solid electrolyte membranes obtained by other demolding methods. The ionic conductivity and electronic conductivity are also better. In terms of mechanical properties, including longitudinal tensile strength, longitudinal elongation at break, transverse tensile strength, transverse elongation at break, and bending radius, the overall performance is also better. This shows that different demolding methods can also change the porosity, ionic conductivity, electronic conductivity, tensile strength, bending radius, and elongation at break of the solid electrolyte membrane, reduce the battery impedance, and improve the battery energy density and cycle life.

[0111] Please refer to Tables 1 and 2. By comparing Example 1 and Comparative Example 6, it can be seen that when the porosity of the skeleton support material is less than 70%, the porosity of the subsequently obtained solid electrolyte membrane (16.8%) is significantly greater than that of Example 1 (7.6%), and the overall performance in terms of conductivity and mechanical properties is also poor.

[0112] Please see Figure 2This is the first charge-discharge curve of the solid electrolyte membrane assembled battery with a skeleton support in Example 2; please refer to... Figure 3 It is the cycling curve of the solid electrolyte membrane assembled battery in Example 2, which is supported by a skeleton. Figure 3 As can be seen, after 40 charge-discharge cycles, the coulombic efficiency of the battery remains at around 100% (curve formed by hollow circles), and the specific capacitance can still be maintained between 138 and 150 mAh / g (curve formed by solid circles), indicating that the skeleton-supported solid electrolyte membrane helps to improve the battery's cycle charge-discharge performance.

[0113] In summary, this invention provides a framework-supported solid electrolyte membrane, its preparation method, and its applications. By introducing a framework support material, the mechanical strength of the electrolyte membrane is improved, the interfacial contact between the electrode and the solid electrolyte membrane is enhanced, and the cycle stability of the battery is increased, while simultaneously improving the battery's energy density and safety. The framework-supported solid electrolyte membrane provided by this invention, while improving the mechanical properties of the solid electrolyte membrane, also possesses flexibility and can fill the microstructure of the electrode surface through elastic deformation, reducing voids between the electrolyte membrane and the electrode interface, preventing crack propagation, lowering interfacial impedance, increasing the ion conduction rate of the solid electrolyte membrane, and reducing the battery's internal resistance. This contributes to achieving longer cycle life and higher power density, thereby enabling low-cost and mass-produced applications of high-energy-density solid-state batteries.

[0114] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A skeleton-supported solid electrolyte membrane, characterized in that, At least including: Skeleton support material; Solid electrolyte, located in the pores of the skeleton support material; as well as An adhesive is incorporated into the pores of the skeleton support material, wherein the median particle size d of the solid electrolyte is smaller than the pore size D1 of the skeleton support material and larger than the pore size D2 of the solid electrolyte membrane.

2. The skeleton-supported solid electrolyte membrane according to claim 1, characterized in that, The median particle size d, the pore size D1, and the pore size D2 satisfy the following relationship: 20 < (D1 - D2) / d < 200.

3. The skeleton-supported solid electrolyte membrane according to claim 1, characterized in that, Includes one or more of the following characteristics: The median particle size d is 0.1 μm to 3.0 μm; The aperture D1 is 40 μm to 100 μm; The aperture D2 is between 50 nm and 300 nm.

4. The skeleton-supported solid electrolyte membrane according to claim 1, characterized in that, The skeleton-supported solid electrolyte membrane comprises 1 to 5 parts by weight of the skeleton support material, 90 to 94 parts by weight of the solid electrolyte, and 1 to 5 parts by weight of the binder.

5. The skeleton-supported solid electrolyte membrane according to claim 4, characterized in that, Includes one or more of the following characteristics: The porosity of the skeleton support material is 60% to 90%; The thickness of the skeleton support material is 5 μm to 30 μm; The weight of the skeleton support material is 1 g / m³. 2 Up to 10 g / m 2 .

6. The skeleton-supported solid electrolyte membrane according to claim 4, characterized in that, The solid electrolyte includes a sulfide solid electrolyte.

7. The skeleton-supported solid electrolyte membrane according to claim 4, characterized in that, The adhesive comprises one or more of polymethyl methacrylate, polyacrylate, acrylate-styrene copolymer, thermoplastic elastomer, polyisobutylene, styrene-butadiene rubber, polyvinylidene fluoride, thermoplastic styrene-butadiene rubber, synthetic rubber, hydrogenated nitrile rubber, butadiene rubber, or nitrile rubber, and the tensile strength of the adhesive is 20-50 MPa.

8. The skeleton-supported solid electrolyte membrane according to claim 4, characterized in that, The skeleton support material includes one of the following: nanofiber membrane, nonwoven fabric, fishing net, microporous nylon membrane, microporous polyimide (PI) membrane, microporous polyethylene (PE) membrane, microporous polypropylene (PP) membrane, woven fabric, nylon filter membrane, polytetrafluoroethylene (PTFE) filter membrane, polypropylene (PP) filter membrane, and polyethersulfone (PES) filter membrane.

9. The skeleton-supported solid electrolyte membrane according to claim 1, characterized in that, Includes one or more of the following characteristics: The bending radius of the skeleton supporting the solid electrolyte membrane is, for example, less than or equal to 3 mm; The longitudinal tensile strength of the skeleton supporting the solid electrolyte membrane is 15.0 MPa to 30.0 MPa, and the longitudinal elongation at break is 14% to 20%. The skeletal support for the solid electrolyte membrane has a transverse tensile strength of 14.0 MPa to 30.0 MPa and a transverse elongation at break of 9% to 20%. The ionic conductivity of the solid electrolyte membrane supported by the skeleton is greater than or equal to 1.0 mS / cm. The electronic conductivity of the solid electrolyte membrane supported by the framework is 2.4 × 10⁻⁶. -10 S / cm up to 3.2×10 -10 S / cm; The thickness of the solid electrolyte membrane supported by the skeleton is less than or equal to 30 μm; The porosity of the solid electrolyte membrane supported by the skeleton is less than or equal to 10%.

10. A method for preparing a framework-supported solid electrolyte membrane as described in any one of claims 1 to 9, characterized in that, At least the following steps are included: Slurry preparation steps: Mix the binder and solid electrolyte evenly to obtain the slurry; Fixing steps: Fix the skeleton support material onto the base film to obtain the skeleton support base film; Coating and film formation step: The slurry is coated on the skeleton support base film, and then heated to form a skeleton electrolyte film on the base film by the binder, the solid electrolyte and the skeleton support material; Separation step: Separate the skeleton electrolyte membrane and the base membrane; as well as Hot pressing step: The skeleton electrolyte membrane is subjected to hot pressing treatment to obtain a skeleton-supported solid electrolyte membrane.

11. The preparation method according to claim 10, characterized in that, Before mixing the binder and the solid electrolyte, the slurry preparation step further includes: uniformly mixing the binder and the solvent, wherein the solvent includes one or more of isobutyl isobutyrate, anisole, cyclopentyl methyl ether, isopentane, n-pentane, cyclohexane, isooctane, cyclopentane, n-hexane, n-heptane, toluene, or xylene; and / or the base film includes a release film or an inorganic base film.

12. The preparation method according to claim 10, characterized in that, The temperature of the heat treatment is 50°C to 100°C; and / or the time of the heat treatment is 2 hours to 12 hours.

13. The preparation method according to claim 10, characterized in that, The separation step further includes: applying a preset pressure to the skeleton electrolyte membrane and the base membrane along the thickness direction of the base membrane until the skeleton electrolyte membrane separates from the base membrane, wherein the preset pressure is less than the pressure of the hot pressing treatment.

14. The preparation method according to claim 10, characterized in that, The hot pressing temperature is 50°C to 100°C; and / or the hot pressing pressure is 50 MPa to 100 MPa; and / or the hot pressing time is 2 hours to 12 hours.

15. A solid-state battery, characterized in that, At least including: Positive electrode sheet; Negative electrode sheet; as well as A framework-supported solid electrolyte membrane is disposed between the positive electrode and the negative electrode, and the framework-supported solid electrolyte membrane is a framework-supported solid electrolyte membrane according to any one of claims 1 to 9 or a framework-supported solid electrolyte membrane obtained by the preparation method according to claim 10.

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