Solid electrolyte membrane, and preparation method therefor and use thereof

Abstract

Disclosed in the present invention are a solid electrolyte membrane, and a preparation method therefor and the use thereof. The solid electrolyte membrane comprises a microarray support membrane and a solid electrolyte material loaded on the microarray support membrane, wherein the microarray support membrane is provided with an array-shaped micropore structure, the duty ratio of the micropore structure being 50%-99%, and the diameter of micropores in the micropore structure being 1-500 μm. The solid electrolyte membrane of the present invention has the effect of homogenizing current density, and is characterized by being ultrathin, highly flexible, capable of homogenizing current density, etc.

Description

A solid electrolyte membrane and its preparation method and application Technical Field

[0001] The present invention relates to the field of lithium metal batteries, and in particular to a solid electrolyte membrane and a preparation method and application thereof. Background Art

[0002] Solid-state lithium metal batteries are a new type of battery technology that offers numerous advantages over traditional lithium-ion batteries, including higher energy density, longer lifespan, safer performance, and faster charging speeds. This means that energy storage systems using solid-state lithium metal batteries can store more energy within the same volume and weight. Higher charge and discharge efficiencies also mean less energy loss and higher utilization efficiency, while improved safety can reduce the risk of accidents.

[0003] The core component of solid-state lithium metal batteries is the solid electrolyte, which offers numerous advantages over traditional liquid electrolytes, including improved stability, higher conductivity, reduced electrolyte loss, and increased safety. Solid electrolytes primarily include oxides, sulfides, halides, polymers, and composite solid electrolytes. Oxides, sulfides, halides, and composite solid electrolytes exhibit high mechanical strength and ionic conductivity. However, these electrolytes exhibit brittleness and poor toughness when fabricated into thin films, making them difficult to form into ultra-thin electrolyte membranes.

[0004] Therefore, designing a solid electrolyte film with ultra-high flexibility and ultra-thinness can greatly reduce process production costs, reduce the total impedance of the battery, and effectively increase the battery energy density, which is crucial to the development of solid-state batteries.

[0005] Summary of the Invention

[0006] The present invention addresses the problem that solid electrolyte membranes in current solid-state batteries are difficult to simultaneously meet the requirements of being ultra-thin and having mechanical properties that can match the existing lithium-ion battery production process. It provides an ultra-thin and excellently flexible solid electrolyte film, its preparation method, and application.

[0007] On one hand, the present invention provides a solid electrolyte membrane, which includes a microarray support membrane and a solid electrolyte material loaded on the microarray support membrane; wherein the microarray support membrane has an array-shaped microporous structure, the duty ratio of the microporous structure is 50%-99%, and the diameter of the micropores in the microporous structure is 1-500μm.

[0008] In some embodiments, the microporous structure has a duty cycle of 80-95%.

[0009] In some embodiments, the diameter of the micropores is 2-100 μm.

[0010] In some specific embodiments, the micropores are micro- or nearly-circular in shape, and more preferably, the micropores have a pore pitch of 0.3-30 μm.

[0011] In some specific embodiments, the material of the microarray support membrane is one or more of polyethylene (PE), polypropylene (PP), polyimide (PI), polyvinylidene fluoride (PVDF), polyethylene terephthalate (PET), and polytetrafluoroethylene (PTFE).

[0012] In some specific embodiments, the thickness of the microarray support membrane is 0.5-100 μm, preferably 1-5 μm.

[0013] In some specific embodiments, the solid electrolyte material is supported inside the microporous structure and on the surface of at least one side of the microarray support membrane.

[0014] In some specific embodiments, the solid electrolyte material is one or more of an oxide solid electrolyte, a sulfide solid electrolyte, a halide solid electrolyte, a polymer solid electrolyte, and a composite solid electrolyte.

[0015] A second aspect of the present invention provides a method for preparing a solid electrolyte membrane, the method comprising:

[0016] (1) providing a microarray support membrane having an array-shaped microporous structure;

[0017] (2) loading a solid electrolyte material inside the microporous structure and on the surface of at least one side of the microarray support membrane;

[0018] The duty cycle of the microporous structure is 50%-99%, and the diameter of the micropores in the microporous structure is 1-500 μm.

[0019] In some embodiments, the microporous structure has a duty cycle of 80-95%.

[0020] In some embodiments, the diameter of the micropores is 2-100 μm.

[0021] In some specific embodiments, the micropores are circular or nearly circular, and more preferably, the micropore pitch is 0.3-30 μm.

[0022] In some specific embodiments, the material of the microarray support membrane is one or more of polyethylene (PE), polypropylene (PP), polyimide (PI), polyvinylidene fluoride (PVDF), polyethylene terephthalate (PET), and polytetrafluoroethylene (PTFE).

[0023] In some specific embodiments, the thickness of the microarray support membrane is 0.5-100 μm, preferably 1-5 μm.

[0024] In some specific embodiments, in step (2), a solid electrolyte membrane is obtained by coating a slurry of a solid electrolyte material onto the microarray support membrane, and then pressurizing and drying the slurry.

[0025] In some specific embodiments, the solid electrolyte material is one or more of an oxide solid electrolyte, a sulfide solid electrolyte, a halide solid electrolyte, a polymer solid electrolyte, and a composite solid electrolyte.

[0026] A third aspect of the present invention provides use of the solid electrolyte membrane of the present invention or the solid electrolyte membrane prepared by the preparation method of the present invention in a lithium metal battery.

[0027] Advantageous Effects of the Invention

[0028] The solid electrolyte membrane of the present invention can realize the preparation of ultra-thin and highly flexible electrolyte films (especially films below 20 μm) by a simple method through the above-mentioned unique structure; thus, the prepared solid electrolyte membrane has the effect of uniforming the current density and can be applied to various types of solid electrolyte materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 shows the structure of the solid electrolyte membrane of the present invention, wherein a is a cross-sectional view of the solid electrolyte membrane, and b is a schematic structural diagram of the microarray support membrane 1 .

[0030] FIG2 shows an electron microscope photograph of the PE microarray support membrane of the present invention.

[0031] FIG3 shows a photograph of the solid electrolyte membrane of Example 1 of the present invention.

[0032] FIG4 shows a photograph of the solid electrolyte membrane of Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0033] The present invention will be further described below through specific embodiments. Unless otherwise specified, the technical terms used herein have the same meanings as those generally understood by those skilled in the art.

[0034] Numerical limits or ranges stated herein are inclusive of the endpoints and specifically include all values ​​and subranges within the numerical limits or ranges.

[0035] A first aspect of the present invention provides a solid electrolyte membrane, which includes a microarray support membrane and a solid electrolyte material loaded on the microarray support membrane; wherein the microarray support membrane has an array-shaped microporous structure, the duty ratio of the microporous structure is 50%-99%, and the diameter of the micropores in the microporous structure is 1-500μm.

[0036] As shown in Figure 1, the solid electrolyte membrane of the present invention comprises a microarray support membrane 1 and a solid electrolyte material 2. The microarray support membrane provides excellent flexibility and toughness for the solid electrolyte membrane as a whole. The microarray support membrane has a periodically arranged microporous structure, and the solid electrolyte material fills the microporous structure and adheres to one or both sides of the microarray support membrane. This structure allows lithium ions to pass from one side of the electrolyte membrane to the other through the pores, achieving ion exchange.

[0037] In the present invention, the "duty ratio of the microporous structure" refers to the ratio of the total pore area of ​​the microporous structure to the total area of ​​the microarray support membrane. The diameters of the micropores in the microporous structure may be equal or unequal. If unequal, the diameters herein are expressed as the average diameter. From the perspective of the overall strength and uniformity of the microarray support membrane, it is preferred that the diameters of all micropores be within the range of D ± 10% (preferably D ± 5%, more preferably D ± 2%), where D represents the average diameter of all micropores in the microarray support membrane.

[0038] According to the present invention, the solid electrolyte material is loaded on the interior and at least one side surface of the microporous structure of the microarray support membrane. For example, the solid electrolyte material slurry can be coated on the microarray support membrane and pressurized and dried once so that the solid electrolyte material is loaded on the interior and at least one side surface, preferably on both sides surface, of the microporous structure of the microarray support membrane.

[0039] In the present invention, the microarray support membrane can use any polymer film material commonly used for lithium metal battery separators, for example, polyethylene (PE), polypropylene (PP), polyimide (PI), polyvinylidene fluoride (PVDF), polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE) or more. The microarray support membrane can be a single-layer membrane or a laminated membrane formed by a multilayer membrane. Preferably, the thickness of the microarray support membrane is 0.5-100 μm, preferably 1-5 μm. In addition, the total thickness of the solid electrolyte membrane can be 5-1000 μm, preferably 7-20 μm.

[0040] In addition, the thickness of the microarray support film can be, for example, 0.5 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm or 100 μm. The total thickness of the solid electrolyte can be, for example, 5 μm, 7 μm, 10 μm, 15 μm, 20 μm, 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm or 1000 μm.

[0041] Moreover, the solid electrolyte membrane of the present invention has no particular limitation on the shape of the micropores in the microporous structure. For example, the shape may be circular or nearly circular, quadrilateral (such as rectangle or square), polygonal (such as regular pentagon, regular hexagon, regular octagon, etc.) or irregular, preferably circular or nearly circular.

[0042] In the present invention, the micropores are preferably evenly distributed in an array over the entire surface of the microarray support membrane, thereby providing a solid electrolyte membrane having good overall flexibility and toughness. Specifically, for example, adjacent micropores may be located at the vertices of an equilateral triangle or a square.

[0043] According to some preferred embodiments of the present invention, when the micropores are circular or nearly circular, the pore pitch of the micropores is 0.3-30 μm, preferably 0.5-20 μm; the diameter of the micropores is 1-500 μm, preferably 2-10 μm. As shown in FIG1 b, when the micropores are circular or nearly circular, R a Represents the diameter of the micropore, (R b -R a ) represents the distance between adjacent micropores (also referred to as the micropore pitch). By forming the micropores into circular or nearly circular shapes, better contact between the electrolyte and the support membrane is achieved, making it less likely for the electrolyte to fall off, while also reducing current concentration.

[0044] In addition, the pore pitch of the micropores can be, for example, 0.3 μm, 0.5 μm, 1 μm, 2 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm or 30 μm, etc.; the diameter of the micropores can be, for example, 1 μm, 2 μm, 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, or 500 μm, etc.

[0045] In the present invention, the method for forming the microporous structure on the microarray support membrane is not particularly limited. As long as the duty ratio and micropore diameter required by the present application are met, a solid electrolyte membrane with appropriate flexibility and toughness can be provided. According to some preferred embodiments of the present invention, the desired microporous structure can be conveniently formed on the microarray support membrane using methods such as laser processing, template processing, and physical / chemical etching.

[0046] To further improve the performance of the solid electrolyte membrane, according to a preferred embodiment of the present invention, the duty cycle of the microporous structure is 80%-95%. According to a preferred embodiment of the present invention, the diameter of the micropores is 5-100 μm, preferably 5-30 μm. In addition, the duty cycle of the microarray can be, for example, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, or 99%.

[0047] According to the present invention, the solid electrolyte material can use any solid electrolyte material commonly used in lithium metal batteries. Specifically, the solid electrolyte material can include, but is not limited to, one or more of an oxide solid electrolyte, a sulfide solid electrolyte, a halide solid electrolyte, a polymer solid electrolyte, and a composite solid electrolyte.

[0048] As oxide solid electrolytes, for example, NASICON type, perovskite type, garnet type, LISICON type, LiPON type, etc. Specifically, lithium lanthanum zirconium oxide (LLZO, Li7La3Zr2O 12 ) or lithium lanthanum titanium oxide (LLTO), etc. As needed, the above oxide solid electrolyte may further contain one or more doping elements selected from aluminum, gallium, and tantalum.

[0049] Sulfide solid electrolytes include binary sulfide electrolytes, ternary sulfide electrolytes, etc. Specifically, they include Li2S-SiS2, Li2S-GeS2, Li2S-P2S5, Li2S-B2S3, Li2S-GeS2-ZnS, and Li2S-GeS2-Ga2S3.

[0050] The polymer solid electrolyte may be, for example, a polyethylene oxide (PEO)-based electrolyte, a polyacrylonitrile (PAN)-based electrolyte, a polyvinylidene fluoride (PVDF)-based electrolyte, a polycarbonate-based electrolyte, a polysiloxane-based electrolyte, or a composite solid electrolyte thereof.

[0051] Composite solid-state electrolytes typically incorporate other fillers into polymer-based electrolytes to improve their ionic conductivity, mechanical properties, and compatibility with electrodes. These fillers include inorganic inert fillers, inorganic active fillers, and porous organic fillers. Commonly used inorganic inert fillers include Al2O3 and SiO2; inorganic active fillers refer to lithium-containing oxide or sulfide electrolytes.

[0052] The solid electrolyte membrane of the present invention can be used for various solid electrolytes by disposing the microarray support membrane with the unique structure, and can achieve good mechanical properties and high ionic conductivity.

[0053] A second aspect of the present invention provides a method for preparing a solid electrolyte membrane, the method comprising:

[0054] (1) providing a microarray support membrane having an array-shaped microporous structure;

[0055] (2) loading a solid electrolyte material inside the microporous structure and on the surface of at least one side of the microarray support membrane;

[0056] The duty cycle of the microporous structure is 50%-99%, and the diameter of the micropores in the microporous structure is 1-500 μm.

[0057] In the present invention, the microarray support membrane can use any polymer membrane material commonly used for lithium metal battery separators, for example, one or more of polyethylene (PE), polypropylene (PP), polyimide (PI), polyvinylidene fluoride (PVDF), polyethylene terephthalate (PET), and polytetrafluoroethylene (PTFE). The microarray support membrane can be a single-layer membrane or a laminated membrane formed by a multilayer membrane. Preferably, the thickness of the microarray support membrane is 0.5-100 μm, preferably 1-5 μm. In addition, the total thickness of the solid electrolyte membrane can be 5-1000 μm, preferably 5-100 μm, and more preferably 7-20 μm.

[0058] In addition, the thickness of the microarray support membrane can be, for example, 0.5 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm or 100 μm, etc.; the total thickness of the solid electrolyte can be, for example, 5 μm, 7 μm, 10 μm, 15 μm, 20 μm, 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm or 1000 μm.

[0059] Moreover, the solid electrolyte membrane of the present invention has no particular limitation on the shape of the micropores in the microporous structure, and may be, for example, circular or nearly circular, quadrilateral (such as a rectangle or a square), polygonal (such as a regular pentagon, a regular hexagon, a regular octagon, etc.) or an irregular shape, preferably circular or nearly circular.

[0060] In the present invention, the micropores are preferably evenly distributed in an array over the entire surface of the microarray support membrane, thereby providing a solid electrolyte membrane having good overall flexibility and toughness. Specifically, for example, adjacent micropores may be located at the vertices of an equilateral triangle or a square.

[0061] According to some preferred embodiments of the present invention, such as in FIG1 b, when the micropores are circular or nearly circular, the micropore pitch can be, for example, 0.3-30 μm, preferably 0.5-20 μm. The micropore diameter can be, for example, 1-500 μm, preferably 2-100 μm. In addition, the pore pitch of the micropores can be, for example, 0.3 μm, 0.5 μm, 1 μm, 2 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm or 30 μm, etc.; the diameter of the micropores can be, for example, 1 μm, 2 μm, 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, or 500 μm, etc.

[0062] In the present invention, the method for forming the microporous structure on the microarray support membrane is not particularly limited. As long as the duty ratio and micropore diameter required by the present application are met, a solid electrolyte membrane with appropriate flexibility and toughness can be provided. According to some preferred embodiments of the present invention, the desired microporous structure can be conveniently formed on the microarray support membrane using methods such as laser processing, template processing, and physical / chemical etching.

[0063] To further improve the performance of the solid electrolyte membrane, according to a preferred embodiment of the present invention, the duty cycle of the microporous structure is 80%-95%. In addition, the duty cycle of the microarray can be, for example, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% or 99%.

[0064] According to the present invention, in step (2), the solid electrolyte material is loaded on the interior of the microporous structure and on the surface of at least one side of the microarray support membrane to obtain the solid electrolyte membrane of the present invention. Specifically, in step (2), the solid electrolyte membrane of the present invention can be obtained by coating a slurry of the solid electrolyte material on the microarray support membrane, and then pressurizing and drying the slurry. The coating can be performed by coating the slurry of the solid electrolyte material on any one or both surfaces of the microarray support membrane.

[0065] According to some specific embodiments of the present invention, a microarray support membrane can be placed on a hard substrate, and a slurry of a solid electrolyte material can be coated on the microarray support membrane, and then pressurized, so that the slurry of the solid electrolyte material enters the microporous structure of the microarray support membrane, allowing lithium ions to pass through the pores from one side of the electrolyte membrane to the other side, thereby realizing ion exchange.

[0066] By loading the solid electrolyte material, the total thickness of the microarray support membrane finally obtained can be 5-1000 μm, preferably 7-20 μm.

[0067] The slurry of the solid electrolyte material can be obtained by mixing the desired solid electrolyte material and a binder or the like as needed with a solvent. The solid electrolyte material can include, but is not limited to, one or more of oxide solid electrolytes, sulfide solid electrolytes, halide solid electrolytes, polymer solid electrolytes, and composite solid electrolytes. Specifically, the solid electrolyte material of the first aspect of the present invention can be selected.

[0068] The binder may be, for example, one or more of polyvinyl butyral (PVB), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyvinyl pyrrolidone (PVP), styrene-butadiene rubber (SBR) emulsion, carboxymethyl cellulose (CMC), polyacrylic acid (PAA), and polyacrylonitrile (PAN). The solvent may be, for example, acetonitrile, N,N-dimethylformamide, tetrahydrofuran, isopropyl alcohol, or the like.

[0069] In the slurry of solid electrolyte material, the amount of solid electrolyte material can be 70-120 parts by weight, preferably 90-100 parts by weight; the amount of binder can be 0.5-5 parts by weight, preferably 1-3 parts by weight; the amount of solvent can be 500-2000 parts by weight, preferably 800-1500 parts by weight.

[0070] In the present invention, in order to obtain a uniform slurry of solid electrolyte material, the above components can be mixed and then further dispersed evenly by ball milling. For example, the ball milling conditions can be: rotation speed 100-1000 rpm, preferably 200-700 rpm; time 1-10 h, preferably 1.5-5 h.

[0071] In the present invention, the method for coating the solid electrolyte material slurry onto the microarray support membrane is not particularly limited, as long as the slurry is evenly dispersed on the surface of the microarray support membrane. For example, a doctor blade coating method can be used. The amount of slurry applied can be adjusted according to the desired thickness of the solid electrolyte membrane.

[0072] In the present invention, in order to allow the slurry of the solid electrolyte material to enter the interior of the microporous structure of the microarray support membrane, the microarray support membrane coated with the slurry can be subjected to a pressure treatment, preferably at a pressure of 50-500 MPa, preferably 100-200 MPa, and a holding time of 2 minutes or more, preferably 2-10 minutes. The pressure treatment can be performed using a flat plate cold press. The pressurized microarray support membrane is then dried using, for example, a vacuum drying oven to obtain the solid electrolyte membrane of the present invention.

[0073] The third aspect of the present invention provides the use of the solid electrolyte membrane described in the first aspect of the present invention, or the solid electrolyte membrane prepared by the preparation method described in the second aspect of the present invention in a lithium metal battery.

[0074] The experimental methods in the following examples are conventional methods unless otherwise specified.

[0075] Example

[0076] Example 1

[0077] This embodiment is used to illustrate the preparation method of an ultra-thin solid electrolyte film.

[0078] (1) Preparation of PI support film

[0079] By laser processing, a micropore array structure consisting of evenly distributed circular holes is formed on a 5 μm PI support film. As shown in FIG1 b, adjacent micropores are located at the vertices of an equilateral triangle with a duty cycle of 58.0%. The diameter of the micropore R a is 80 μm, and the distance between adjacent micropores (R b -R a ) are all 20μm.

[0080] (2) Preparation of LLZO solid electrolyte slurry

[0081] The solid electrolyte slurry includes aluminum-doped lithium lanthanum zirconium oxide electrolyte (Li 6.28Al 0.24 La3Zr2O 12 ), polyvinyl butyral adhesive, isopropyl alcohol solvent, the weight parts of the above components are: aluminum-doped lithium lanthanum zirconium oxide: 98 parts; polyvinyl butyral: 2 parts; isopropyl alcohol: 1000 parts.

[0082] The corresponding materials were weighed according to the above ratios and dispersed evenly by ball milling. The ball milling conditions were: a speed of 500 rpm / min and a duration of 2 h; and a uniformly dispersed composite solid electrolyte slurry was obtained.

[0083] (3) Preparation of ultrathin solid electrolyte films

[0084] A 5μm thick PI support film was laid flat on a glass plate, and the slurry was applied to the film using a doctor blade. The film was removed before the solvent evaporated. After the solvent evaporated in air, the film was cold pressed at 100 MPa for 5 minutes. The film was then dried in a vacuum drying oven to obtain a 20μm thick electrolyte film.

[0085] Example 2

[0086] The only difference between this embodiment and embodiment 1 is that the support membrane with a thickness of 5 μm is replaced with a PE support membrane with a thickness of 5 μm (as shown in FIG2 ). The remaining steps and parameters are exactly the same as those in embodiment 1.

[0087] Example 3

[0088] The only difference between this embodiment and embodiment 1 is that the support membrane with a thickness of 5 μm is replaced with a PTFE support membrane with a thickness of 5 μm. The remaining steps and parameters are exactly the same as those in embodiment 1.

[0089] Example 4

[0090] The only difference between this embodiment and embodiment 1 is that the support film with a thickness of 5 μm is replaced with a PET support film with a thickness of 5 μm. The remaining steps and parameters are exactly the same as those in embodiment 1.

[0091] Example 5

[0092] The only difference between this embodiment and embodiment 1 is that the distance between adjacent microholes is adjusted to 10 μm, so that the duty cycle is 71.7%. The remaining steps and parameters are exactly the same as those in embodiment 1.

[0093] Example 6

[0094] The only difference between this embodiment and embodiment 1 is that the distance between adjacent microholes is adjusted to 5 μm, so that the duty cycle is 80.3%. The remaining steps and parameters are exactly the same as those in embodiment 1.

[0095] Example 7

[0096] The only difference between this embodiment and embodiment 1 is that the distance between adjacent microholes is adjusted to 3 μm, so that the duty cycle is 84.3%. The remaining steps and parameters are exactly the same as those in embodiment 1.

[0097] Example 8

[0098] The only difference between this embodiment and embodiment 7 is that the diameter of the micropores is adjusted to 60 μm, so that the duty cycle is 82.3%. The remaining steps and parameters are exactly the same as those in embodiment 7.

[0099] Example 9

[0100] The only difference between this embodiment and embodiment 7 is that the diameter of the micropores is adjusted to 40 μm, so that the duty cycle is 78.5%. The remaining steps and parameters are exactly the same as those in embodiment 7.

[0101] Example 10

[0102] The only difference between this embodiment and embodiment 7 is that the diameter of the micropores is adjusted to 20 μm, so that the duty cycle is 68.6%. The remaining steps and parameters are exactly the same as those in embodiment 7.

[0103] Comparative Example 1

[0104] The only difference between this comparative example and Example 1 is that no microporous array support film is used, the slurry is directly scraped onto the PET film, and the film is peeled off from the PET after drying.

[0105] Comparative Example 2

[0106] The only difference between this comparative example and Example 1 is that the distance between adjacent microholes is adjusted to 30 μm, so that the duty cycle is 48.0%. The remaining steps and parameters are exactly the same as those in Example 1.

[0107] Test Case

[0108] This test case is used to illustrate the application of solid electrolyte membranes in semi-solid lithium metal batteries.

[0109] The solid electrolyte membranes prepared in the above examples and comparative examples were bonded to stainless steel gaskets on both sides and hot pressed at 90°C and 1 MPa for 10 minutes. After cooling, the batteries were packaged in button cell cases and tested for ionic conductivity.

[0110] Test conditions: room temperature

[0111] Test method: AC impedance test

[0112] Testing instrument: Wantong electrochemical workstation

[0113] The ionic conductivity and thickness of the solid electrolyte membranes prepared in the above examples and comparative examples were measured, and the results are shown in Table 1.

[0114] Table 1

[0115] Figures 3 and 4 show photographs of the solid electrolyte membranes of Example 1 of the present invention and Comparative Example 1, respectively. By comparison, it can be seen that the solid electrolyte membrane of Example 1 still has good flexibility at a thickness of less than 20 μm, and can meet the production requirements of soft-pack batteries; while the solid electrolyte membrane of Comparative Example 1 is highly fragile, and can only form a film with a thickness of more than 100 μm. It has poor mechanical properties and cannot be used in the soft-pack production process.

[0116] The results in Table 1 show that the use of the solid electrolyte membrane of the present invention can reduce the thickness of the electrolyte membrane and, by increasing the duty cycle, unaffect the ionic conductivity of the electrolyte membrane by the support membrane. In contrast, the solid electrolyte membrane of the comparative example, which does not meet the requirements of the present invention, has poor mechanical properties, cannot reach a thickness below 20 μm, and cannot meet the production process requirements of soft-pack batteries.

[0117] The above examples are used to describe exemplary embodiments of the present invention, but the present invention is not limited thereto. It should be understood by those skilled in the art that the above examples are for illustrative purposes only, and the specific embodiments and examples of the present invention should not be construed as limiting the scope of the present invention. The embodiments can be changed and modified within the scope of the present invention, and such changes and modifications should fall within the scope of protection of the present invention.

Claims

1. A solid electrolyte membrane, characterized in that: The solid electrolyte membrane comprises a microarray support membrane and a solid electrolyte material loaded on the microarray support membrane; The microarray support membrane has an array-shaped microporous structure, the duty ratio of the microporous structure is 50%-99%, and the diameter of the micropores in the microporous structure is 1-500 μm.

2. The solid electrolyte membrane according to claim 1, wherein The duty ratio of the microporous structure is 80-95%.

3. The solid electrolyte membrane according to claim 1 or 2, wherein: The diameter of the micropores is 2-100 μm; Preferably, the micropores are circular or nearly circular, and more preferably, the micropore pitch is 0.3-30 μm.

4. The solid electrolyte membrane according to any one of claims 1 to 3, wherein: The material of the microarray support film is one or more of polyethylene (PE), polypropylene (PP), polyimide (PI), polyvinylidene fluoride (PVDF), polyethylene terephthalate (PET), and polytetrafluoroethylene (PTFE).

5. The solid electrolyte membrane according to any one of claims 1 to 4, wherein: The thickness of the microarray support film is 0.5-100 μm, preferably 1-5 μm.

6. The solid electrolyte membrane according to any one of claims 1 to 5, wherein: The solid electrolyte material is supported inside the microporous structure and on the surface of at least one side of the microarray support membrane.

7. The solid electrolyte membrane according to any one of claims 1 to 6, wherein: The solid electrolyte material is one or more of an oxide solid electrolyte, a sulfide solid electrolyte, a halide solid electrolyte, a polymer solid electrolyte and a composite solid electrolyte.

8. A method for preparing a solid electrolyte membrane, characterized in that: The preparation method comprises: (1) providing a microarray support membrane having an array-shaped microporous structure; (2) loading a solid electrolyte material inside the microporous structure and on the surface of at least one side of the microarray support membrane; The duty cycle of the microporous structure is 50%-99%, and the diameter of the micropores in the microporous structure is 1-500 μm.

9. The preparation method according to claim 8, wherein: The duty ratio of the microporous structure is 80-95%.

10. The preparation method according to claim 8 or 9, wherein: The diameter of the micropores is 2-100 μm; Preferably, the micropores are circular or nearly circular, and more preferably, the micropore pitch is 0.3-30 μm.

11. The preparation method according to any one of claims 8 to 10, wherein The material of the microarray support film is one or more of polyethylene (PE), polypropylene (PP), polyimide (PI), polyvinylidene fluoride (PVDF), polyethylene terephthalate (PET), and polytetrafluoroethylene (PTFE).

12. The preparation method according to any one of claims 8 to 11, wherein The thickness of the microarray support film is 0.5-100 μm, preferably 1-5 μm.

13. The preparation method according to any one of claims 8 to 12, wherein In step (2), a solid electrolyte membrane is obtained by coating a slurry of a solid electrolyte material onto the microarray support membrane, and then pressurizing and drying the slurry.

14. The preparation method according to any one of claims 8 to 13, wherein The solid electrolyte material is one or more of an oxide solid electrolyte, a sulfide solid electrolyte, a halide solid electrolyte, a polymer solid electrolyte and a composite solid electrolyte.

15. Use of the solid electrolyte membrane according to any one of claims 1 to 7 or the solid electrolyte membrane prepared by the preparation method according to any one of claims 8 to 14 in a lithium metal battery.

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