Solid-state electrolyte membrane and preparation method thereof, solid-state battery and electric equipment

Abstract

The invention provides a solid electrolyte membrane and a preparation method thereof, a solid-state battery and electric equipment. The solid-state electrolyte membrane comprises inorganic oxide solid-state electrolyte particles, inorganic oxide filler, a coupling agent, an organic matrix and lithium salt, the inorganic oxide solid-state electrolyte particles are Li < 7-3x > La < 3 > Zr < 2 > Al < x > O < 12 >, and x is greater than or equal to 0.1 and less than or equal to 0.4; the coupling agent is a boron-containing unsaturated compound, the chemical structural formula is R1-B (OR2) 2, and R1 represents an unsaturated bond-containing alkyl group with the carbon atom number of 2-12, or a group in which part or all of hydrogen atoms in the alkyl group are substituted by any one of halogen, alkoxy or aryl; and R2 represents a hydrogen atom, an alkyl group having 1-6 carbon atoms, an alkenyl group having 2-6 carbon atoms, an alkynyl group having 2-6 carbon atoms, an aryl group, or a boron-containing heterocyclic structure formed by two R2 and a boron atom. Therefore, the solid electrolyte membrane can simultaneously have the properties of high conductivity, low impedance, high toughness and the like.

Description

Technical Field

[0001] This invention relates to the field of battery technology, specifically to solid electrolyte membranes and their preparation methods, solid batteries, and electrical devices. Background Technology

[0002] Solid-state batteries, with their high energy density (>350Wh / kg) and inherent safety, are considered the ultimate solution for next-generation energy storage systems. However, their core bottleneck lies in the electrolyte. Traditional liquid electrolytes pose risks such as flammability, leakage, and thermal runaway, while all-solid-state electrolytes have long been plagued by the ternary contradiction of "ion conduction-mechanical strength-interface stability." Garnet-type Li7La3Zr2O 12 (LLZO) has high room temperature ionic conductivity, but it is brittle and difficult to make into flexible films. Grain boundary defects can easily induce local current concentration. Dendrites can penetrate at 0.2-0.5 mA / cm, causing the battery to short-circuit after a certain number of cycles. Although doping with elements such as Al and Ta can improve the bulk conductivity, it cannot guarantee the mechanical strength and / or interface stability of the electrolyte film. Summary of the Invention

[0003] The present invention aims to at least partially solve one of the technical problems in the related art. Therefore, one object of the present invention is to provide a solid electrolyte membrane that simultaneously possesses properties such as high conductivity, low impedance, and high toughness.

[0004] In one aspect, the present invention provides a solid electrolyte membrane. According to an embodiment of the present invention, the solid electrolyte membrane comprises: inorganic oxide solid electrolyte particles, inorganic oxide filler, coupling agent, organic matrix, and lithium salt, wherein the inorganic oxide solid electrolyte particles are Li... 7-3x La3Zr2Al x O 12 Where 0.1 ≤ x ≤ 0.4; the coupling agent is a boron-containing unsaturated compound with the chemical structural formula R. 1 -B(OR 2 )2, where R 1 Represents a hydrocarbon group containing unsaturated bonds with 2 to 12 carbon atoms, or a hydrocarbon group in which some or all of the hydrogen atoms are substituted by any one of a halogen, alkoxy, or aryl group; R 2 This indicates a hydrogen atom, an alkyl group with 1 to 6 carbon atoms, an alkenyl group with 2 to 6 carbon atoms, an alkynyl group with 2 to 6 carbon atoms, an aryl group, or two R groups. 2The boron-containing heterocyclic structure is formed with boron atoms. Therefore, a boron-containing coupling agent is used to form covalent bonds on the surface of the ceramic electrolyte, while simultaneously enabling free radical copolymerization with the organic matrix. This effectively reduces interfacial resistance, optimizes particle size distribution, suppresses local current concentration, and simultaneously improves the tensile strength and flexibility of the solid electrolyte membrane. Furthermore, the presence of aluminum doping in the electrolyte particles allows these inorganic oxide electrolyte particles to provide a high concentration of lithium vacancies, thereby effectively improving the ionic conductivity of the electrolyte membrane. The coupling agent can also form covalent bonds on the surface of these electrolyte particles, helping to reduce interfacial resistance. Thus, the solid electrolyte membrane can simultaneously possess high conductivity, low impedance, and high toughness.

[0005] According to an embodiment of the present invention, R 1 R represents an aryl group substituted with an alkenyl or hydrocarbon group. 2 It represents an alkyl group with 1 to 6 carbon atoms or two R atoms. 2 The coupling agent comprises a boron-containing heterocyclic structure with a total number of 5 to 7 boron atoms. Optionally, the coupling agent includes at least one of 4-vinylphenylboronic acid, 3-vinylphenylboronic acid, 2-vinylphenylboronic acid, 4-vinylphenylboronic acid pinacol ester, 3-vinylphenylboronic acid pinacol ester, 2-vinylphenylboronic acid pinacol ester, 2-vinyl-1,3,2-dioxoboronyl ring, and 2-isopropenyl-1,3,2-dioxoboronyl ring.

[0006] According to an embodiment of the present invention, the difference between the particle size D50 of the inorganic oxide solid electrolyte particles and the particle size D50 of the inorganic oxide filler is 0 to 0.2 μm, and the particle size D50 of the inorganic oxide solid electrolyte particles and the particle size D50 of the inorganic oxide filler are both less than or equal to 0.5 μm.

[0007] According to an embodiment of the present invention, the solid electrolyte membrane further satisfies at least one of the following conditions: the mass ratio of the inorganic oxide solid electrolyte particles to the coupling agent is 100:(0.15 to 0.35); the mass ratio of the inorganic oxide solid electrolyte particles to the inorganic oxide filler is 100:(0.3 to 1.5).

[0008] According to an embodiment of the present invention, the organic matrix comprises a polyether monomer and a crosslinking agent, wherein the mass ratio of the polyether monomer to the crosslinking agent is 100:(2-10).

[0009] According to an embodiment of the present invention, the inorganic oxide solid electrolyte particles are Li 7-3x La3Zr2Al x O 12Wherein, 0.1 ≤ x ≤ 0.4; optionally, the inorganic oxide filler includes at least one of Al2O3, ZrO2, and TiO2; optionally, the polyether monomer includes at least one of polyethylene glycol dimethacrylate, methoxy polyethylene glycol acrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, polyethylene glycol hydroxyethyl methacrylate, and ethoxylated trimethylolpropane triacrylate; optionally, the crosslinking agent includes at least one of pentaerythritol tetraacrylate, di-trimethylolpropane tetraacrylate, trimethylolpropane triacrylate, triallyl isocyanurate, pentaerythritol triacrylate, and tetramethylolmethane tetraacrylate; optionally, the lithium salt can be selected from at least one of LiPF6, LiFSI, LiTFSI, LiBOB, LiDFOB, LiODFB, LiBF4, and LiClO4.

[0010] In another aspect, the present invention provides a method for preparing the aforementioned solid electrolyte membrane. According to an embodiment of the present invention, the method for preparing the solid electrolyte membrane includes: uniformly dispersing inorganic oxide solid electrolyte particles and inorganic oxide fillers in a solvent to obtain a dispersion; adding a coupling agent to the dispersion, and obtaining a composite powder by reflux and separation; mixing the composite powder, lithium salt, organic matrix, and initiator in an organic solvent and vacuum degassing to obtain a composite slurry; coating the composite slurry into a film and vacuum drying to obtain a composite membrane; hot-pressing the composite membrane in an inert atmosphere and drying it to obtain the solid electrolyte membrane. Thus, the solid electrolyte membrane prepared by the above method uses a boron-containing coupling agent to form covalent bonds on the surface of the ceramic electrolyte, and can simultaneously copolymerize with the organic matrix using free radicals, effectively reducing interfacial resistance, optimizing particle size distribution, suppressing local current concentration, and simultaneously effectively improving the tensile strength and flexibility of the solid electrolyte membrane. Combined with the good ionic conductivity of the inorganic oxide solid electrolyte particles, the solid electrolyte membrane can simultaneously possess the effects of high conductivity, low impedance, and high toughness.

[0011] According to an embodiment of the present invention, the preparation method satisfies at least one of the following conditions: the mass ratio of the composite powder to the lithium salt is 14:(1-2); the mass ratio of the composite powder to the volume of the organic matrix is ​​14:(3-7); the room temperature viscosity of the composite slurry is 2200-2700 mPa·s; and the vacuum drying method is: the vacuum drying is carried out sequentially at 55-65°C and 75-90°C.

[0012] In another aspect, the present invention provides a solid-state battery. According to an embodiment of the invention, the solid-state battery includes the solid electrolyte membrane described above, or includes a solid electrolyte membrane prepared by the aforementioned method. Therefore, the solid-state battery exhibits excellent battery performance. Those skilled in the art will understand that the solid-state battery possesses all the features and advantages of the solid electrolyte membrane described above, which will not be elaborated further here.

[0013] In another aspect, the present invention provides an electrical device. According to an embodiment of the invention, the electrical device includes the aforementioned solid-state battery. The battery of the electrical device has superior battery performance.

[0014] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0015] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0016] Figure 1 This is a flowchart of the preparation of a solid electrolyte membrane in one embodiment of the present invention. Detailed Implementation

[0017] The present invention will be explained below with reference to embodiments. Those skilled in the art will understand that the following embodiments are for illustrative purposes only and should not be considered as limiting the scope of the invention. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in the field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0019] In the description of this application, the term "comprising" means "including but not limited to". The terms first, second, third, etc. are used merely as illustrative purposes and do not impose numerical requirements or establish an order.

[0020] In this application, "at least one" means one or more, and "more than one" means two or more. "One or more", "at least one of the following", or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0021] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.

[0022] The present invention will now be described with reference to specific embodiments. It should be noted that these embodiments are merely descriptive and do not limit the present invention in any way.

[0023] In one aspect, the present invention provides a solid electrolyte membrane. According to an embodiment of the present invention, the solid electrolyte membrane comprises: inorganic oxide solid electrolyte particles, inorganic oxide filler, coupling agent, organic matrix, and lithium salt, wherein the inorganic oxide solid electrolyte particles are Li... 7-3x La3Zr2Al x O 12 Where 0.1 ≤ x ≤ 0.4; the coupling agent is a boron-containing unsaturated compound with the chemical structural formula R. 1 -B(OR 2 )2, where R 1 Represents a hydrocarbon group containing unsaturated bonds with 2 to 12 carbon atoms, or a hydrocarbon group in which some or all of the hydrogen atoms are substituted by any one of a halogen, alkoxy, or aryl group; R 2 This indicates a hydrogen atom, an alkyl group with 1 to 6 carbon atoms, an alkenyl group with 2 to 6 carbon atoms, an alkynyl group with 2 to 6 carbon atoms, an aryl group, or two R groups. 2The boron-containing heterocyclic structure is formed with boron atoms. Therefore, a boron-containing coupling agent is used to form covalent bonds on the surface of the ceramic electrolyte, while simultaneously enabling free radical copolymerization with the organic matrix. This effectively reduces interfacial resistance, optimizes particle size distribution, suppresses local current concentration, and simultaneously improves the tensile strength and flexibility of the solid electrolyte membrane. Furthermore, the presence of aluminum doping in the electrolyte particles allows these inorganic oxide electrolyte particles to provide a high concentration of lithium vacancies, thereby effectively improving the ionic conductivity of the electrolyte membrane. The coupling agent can also form covalent bonds on the surface of these electrolyte particles, helping to reduce interfacial resistance. Thus, the solid electrolyte membrane can simultaneously possess high conductivity, low impedance, and high toughness.

[0024] According to some embodiments of the present invention, R 1 R represents an aryl group substituted with an alkenyl or hydrocarbon group. 2 It represents an alkyl group with 1 to 6 carbon atoms or two R atoms. 2 It forms a boron-containing heterocyclic structure with a total number of 5 to 7 boron atoms. In some specific embodiments, the coupling agent includes at least one of 4-vinylphenylboronic acid, 3-vinylphenylboronic acid, 2-vinylphenylboronic acid, 4-vinylphenylboronic acid pinacol ester, 3-vinylphenylboronic acid pinacol ester, 2-vinylphenylboronic acid pinacol ester, 2-vinyl-1,3,2-dioxoboronyl ring, and 2-isopropenyl-1,3,2-dioxoboronyl hexane ring. Therefore, if the boron-containing unsaturated compound contains boric acid groups, these groups first undergo dehydration condensation with the hydroxyl groups on the surface of the inorganic oxide solid electrolyte particles. Simultaneously, the lone pair electrons on the boron atoms interact weakly with the surface oxygen atoms, further strengthening the anchoring effect. If alkenyl groups are used to provide unsaturated bonds, polymerizable alkenyl units are introduced into the outer edge of the particles. These alkenyl groups covalently connect with the organic matrix during subsequent cross-linking, forming a continuous three-dimensional network, thereby enhancing the interfacial bonding between the particles and the organic matrix and inhibiting dendrite growth. Furthermore, the introduction of aryl groups allows them to interact with the inorganic oxide solid electrolyte particles. The coplanar condensation of particles results in better anchoring. The alkenyl group provides unsaturated bonds, allowing it to be appropriately distanced from the boron atom. Furthermore, when the alkenyl group and boron atom are aligned in the para-position on the benzene ring, the steric hindrance is smaller, leading to higher free radical polymerization activity. In this case, the boron-containing unsaturated compound can further strengthen the particle-polymer interface bonding by introducing additional ester groups. The ester groups have good affinity for polar solvents, which is beneficial for slurry dispersion and coating. Using a cyclic borate ester structure without aryl groups results in moderate ring strain, faster condensation reactions, and if an alkenyl group is used to provide unsaturated bonds outside the ring, it also possesses high free radical activity.

[0025] According to some embodiments of the present invention, the difference between the particle size D50 of the inorganic oxide solid electrolyte particles and the particle size D50 of the inorganic oxide filler is 0–0.2 μm (e.g., differences of 0 μm, 0.02 μm, 0.04 μm, 0.06 μm, 0.08 μm, 0.10 μm, 0.12 μm, 0.14 μm, 0.16 μm, 0.18 μm, 0.20 μm), and the particle size D50 of both the inorganic oxide solid electrolyte particles and the inorganic oxide filler is less than or equal to 0.5 μm. Therefore, the particle size D50 of the inorganic oxide solid electrolyte particles and the inorganic oxide filler are similar, allowing for a more compact packing, thereby reducing the porosity of the solid electrolyte membrane without blocking ion channels.

[0026] According to some embodiments of the present invention, the mass ratio of inorganic oxide solid electrolyte particles to coupling agent is 100:(0.15~0.35), for example, 100:0.15, 100:0.20, 100:0.25, 100:0.30, and 100:0.35. Therefore, the above-mentioned ratio allows for sufficient interaction between the inorganic oxide electrolyte particles and the coupling agent, better achieving the effect of the solid electrolyte membrane simultaneously possessing high conductivity, low impedance, and high toughness.

[0027] According to some embodiments of the present invention, the mass ratio of inorganic oxide solid electrolyte particles to inorganic oxide filler is 100:(0.3-1.5), such as 100:0.3, 100:0.5, 100:0.8, 100:1.0, 100:1.1, 100:1.2, 100:0.3, 100:0.4, 100:1.5, etc. Therefore, the above-mentioned proportion of inorganic oxide filler can effectively improve the interfacial shear strength between the electrolyte particles and the organic matrix, thereby enhancing the mechanical properties of the electrolyte membrane.

[0028] According to some embodiments of the present invention, x can be 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, or 0.40, and the corresponding chemical formulas of the inorganic oxide solid electrolyte particles are Li, respectively. 6.7 La3Zr2Al 0.1 O 12 Li 6.55 La3Zr2Al 0.15 O 12 Li 6.4 La3Zr2Al 0.2 O 12 Li 6.25 La3Zr2Al 0.25 O 12 Li 6.1La3Zr2Al 0.3 O 12 Li 5.95 La3Zr2Al 0.35 O 12 Li 5.8 La3Zr2Al 0.4 O 12 .

[0029] According to some embodiments of the present invention, the inorganic oxide filler includes at least one of Al2O3, ZrO2, and TiO2. Therefore, the aforementioned inorganic oxide filler possesses a high surface hydroxyl density, which helps to improve the interfacial shear strength of the particle-organic matrix and achieves a good mechanical strength reinforcement effect.

[0030] According to some embodiments of the present invention, the organic matrix comprises a polyether monomer and a crosslinking agent. The polyether monomer comprises at least one of polyethylene glycol dimethacrylate, methoxy polyethylene glycol acrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, polyethylene glycol hydroxyethyl methacrylate, and ethoxylated trimethylolpropane triacrylate. The crosslinking agent comprises at least one of pentaerythritol tetraacrylate, di-trimethylolpropane tetraacrylate, trimethylolpropane triacrylate, triallyl isocyanurate, pentaerythritol triacrylate, and tetramethylolmethane tetraacrylate. Therefore, the main chain of the polyether monomer is a polyether unit, and the crosslinking agents are all selected from multifunctional crosslinking agents. The polyether monomer has a low crosslinking density, a large network crosslinking point spacing, and a high degree of freedom of chain segment movement, while the crosslinking agent has a high crosslinking density, which is beneficial to improving the Young's modulus of the organic matrix. The coupling agent forms covalent bonds on the surface of the electrolyte particles, and at the same time introduces polymerizable units that can undergo free radical copolymerization with the polyether monomer and the crosslinking agent, thereby enabling the electrolyte particles to undergo free radical copolymerization with the acrylate segments in the polyether monomer, achieving covalent connection, forming a continuous three-dimensional network, enhancing the interfacial bonding between the electrolyte particles and the organic matrix, reducing the interfacial resistance, and inhibiting dendrite growth.

[0031] According to some embodiments of the present invention, the mass ratio of polyether monomer to crosslinking agent is 100:(2-10), for example, mass ratios of 100:2, 100:3, 100:4, 100:5, 100:6, 100:7, 100:8, 100:9, and 100:10. The mass ratio of polyether monomer to crosslinking agent mainly affects the spacing between crosslinking points. The above ratios can make the spacing between crosslinking points suitable without significantly affecting the ionic conductivity. When the mass of crosslinking agent increases, the crosslinking points become denser and the modulus increases, but this will lead to a certain degree of decrease in ionic conductivity.

[0032] According to some embodiments of the present invention, the lithium salt may be selected from at least one of LiPF6 (lithium hexafluorophosphate), LiFSI (lithium bisfluorosulfonylimide), LiTFSI (lithium bistrifluoromethanesulfonylimide), LiBOB (lithium bis(oxalateborate), LiDFOB (lithium difluorooxalateborate), LiODFB (lithium difluorooxalateborate), LiBF4 (lithium tetrafluoroborate), and LiClO4 (lithium perchlorate).

[0033] According to some embodiments of the present invention, the thickness of the solid electrolyte membrane is 72-78 μm, such as 72 μm, 73 μm, 74 μm, 75 μm, 76 μm, 77 μm, 78 μm, etc.

[0034] In another aspect, the present invention provides a method for preparing the aforementioned solid electrolyte membrane. According to an embodiment of the present invention, referring to... Figure 1 Methods for preparing solid electrolyte membranes include:

[0035] S1: Inorganic oxide solid electrolyte particles and inorganic oxide fillers are uniformly dispersed in a solvent to obtain a dispersion.

[0036] In some embodiments, the solvent may be a mixture of ethanol and water, wherein there is no limitation on the mixing ratio, and those skilled in the art can flexibly choose according to actual needs.

[0037] In some embodiments, ultrasonic dispersion may be used.

[0038] S2: Add a coupling agent to the dispersion, and obtain a composite powder by reflux and separation. Reflux allows the coupling agent molecules to be fully and uniformly grafted onto the surface of inorganic oxide solid electrolyte particles and inorganic oxide fillers at a constant temperature, forming stable chemical bonds, improving the inorganic-organic interfacial bonding strength, and preventing the coupling agent from prematurely precipitating or self-polymerizing due to solvent evaporation.

[0039] According to embodiments of the present invention, if the coupling agent is an alkenyl-aryl-boronic acid organic compound (such as 4-vinylphenylboronic acid, 3-vinylphenylboronic acid, 2-vinylphenylboronic acid), during reflux, the boronic acid groups hydrolyze to boron hydroxyl groups, which undergo dehydration condensation with the terminal hydroxyl groups on the surface of the inorganic oxide solid electrolyte particles and inorganic oxide fillers to generate stable covalent bonds. Thus, the inorganic-organic interface does not slip or de-adhede during cycling. Simultaneously, the terminal alkenyl groups can undergo free radical copolymerization with the subsequently added organic matrix (polyether monomers and crosslinking agents), further improving tensile strength and Young's modulus. If the coupling agent is an alkenyl-aryl-boronic acid ester organic compound (such as 4-vinylphenylboronic acid pinacol ester, 3-vinylphenylboronic acid pinacol ester, 2-...), Vinylphenylboronic acid pinacol ester), during reflux, the borate ester group first rapidly hydrolyzes to generate borate groups, which then undergo dehydration condensation with the terminal hydroxyl groups on the surface of inorganic oxide solid electrolyte particles and inorganic oxide fillers. If the coupling agent is a cyclic organic compound without aryl groups (such as 2-vinyl-1,3,2-dioxoborane ring, 2-isopropenyl-1,3,2-dioxoborane ring), such as 2-vinyl-1,3,2-dioxoborane ring, its configuration is a five-membered boron-dioxo heterocycle in a near-planar shape, with the vinyl group located at the para position of the boron atom. During reflux, the BOC bond in the ring breaks and hydrolyzes in situ, forming covalent bonds with inorganic oxide solid electrolyte particles and inorganic oxide fillers. The anchoring density is higher than that of straight-chain borate esters, and the interfacial shear strength is also greater.

[0040] In some specific embodiments, the reflux step may include: transferring the entire dispersion into a three-necked flask, connecting a spherical condenser to the middle neck, magnetically stirring at 500–700 rpm to ensure no sedimentation of particles, setting the oil bath temperature to 80–90°C (e.g., 85°C), controlling the temperature inside the three-necked flask to rise to 75–85°C (e.g., 80°C) within 3–8 minutes, causing reflux dripping to appear at the lower end of the condenser, pre-dissolving the coupling agent, and uniformly adding the pre-solventized coupling agent to the three-necked flask through the side opening, and refluxing at 80°C for 1 hour after the addition is complete.

[0041] According to some embodiments of the present invention, step S2 may further include: further dispersing the solid mixture obtained after reflux and separation in anhydrous ethanol, ultrasonically treating it at 35-45 kHz for 5-20 min, and drying it to obtain a composite powder. The ultrasonic treatment described above can generate cavitation bubbles of 2-3 μm, which facilitates the peeling of the adsorption layer on the particle surface without destroying covalent bonds and significantly reducing the secondary agglomeration rate of the powder.

[0042] S3: The composite powder, lithium salt, organic matrix (i.e., polyether monomer and crosslinking agent) and initiator are mixed in an organic solvent and degassed under vacuum to obtain a composite slurry.

[0043] In step S2 above, after the solid electrolyte particles are modified by the coupling agent, the polymerizable units introduced on the outer edge of the solid electrolyte particles will undergo free radical copolymerization with the polyether monomer and crosslinking agent, thereby covalently connecting the solid electrolyte particles with the organic matrix to form a continuous three-dimensional network, enhancing the interfacial bonding between the solid electrolyte particles and the organic matrix, and inhibiting dendrite growth.

[0044] In some embodiments, the organic solvent is a polar aprotic solvent, such as, but not limited to, one of DMSO (dimethyl sulfoxide), NMP (N-methylpyrrolidone), DMF (N,N-dimethylformamide), and DMAC (N,N-dimethylacetamide). Therefore, using a polar aprotic solvent avoids the hydrolysis of fluorinated lithium salts to generate HF.

[0045] In some embodiments, the initiator may include, but is not limited to, azobisisobutyronitrile (AIBN).

[0046] In some embodiments, the lithium salt may be selected from at least one of LiPF6, LiFSI, LiTFSI, LiBOB, LiDFOB, LiODFB, LiBF4, and LiClO4.

[0047] In some embodiments, the addition of the organic matrix is ​​achieved by adding a polyether monomer and a crosslinking agent. The polyether monomer includes at least one of polyethylene glycol dimethacrylate, methoxy polyethylene glycol acrylate, polyethylene glycol diacrylate (PEGDA), polypropylene glycol diacrylate, polyethylene glycol hydroxyethyl methacrylate, and ethoxylated trimethylolpropane triacrylate. The crosslinking agent includes at least one of pentaerythritol tetraacrylate, di-trimethylolpropane tetraacrylate, trimethylolpropane triacrylate, triallyl isocyanurate, pentaerythritol triacrylate, and tetramethylolmethane tetraacrylate.

[0048] In some specific embodiments, the vacuum degassing step includes: sequentially adding organic solvent, lithium salt, organic matrix, initiator, and composite powder into a dual planetary vacuum degassing machine; sequentially wetting at 30°C with atmospheric pressure at 20 rpm rotation and 15 rpm revolution; initial degassing at 100-200 mbar with 25 rpm rotation and 20 rpm revolution; fine degassing at 80 mbar with 30 rpm rotation and 25 rpm revolution; and pressure holding at 80 mbar with 10 rpm rotation and 8 rpm revolution, ultimately ensuring that the composite slurry is free of visible bubbles. During the degassing process, organic solvents can be added appropriately to control the room temperature viscosity of the composite slurry at 2200-2700 mPa·s, such as 2200 mPa·s, 2250 mPa·s, 2300 mPa·s, 2350 mPa·s, 2400 mPa·s, 2450 mPa·s, 2500 mPa·s, 2550 mPa·s, 2600 mPa·s, 2650 mPa·s, 2700 mPa·s, etc., so that it can be incorporated into the film formation of the composite slurry in subsequent steps.

[0049] In some embodiments, the solid content of the composite slurry is 47-50 wt%.

[0050] In some embodiments, the mass ratio of composite powder to lithium salt is 14:(1-2), such as 14:1, 14:1.1, 14:1.2, 14:1.3, 14:1.4, 14:1.5, 14:1.6, 14:1.7, 14:1.8, 14:1.9, 14:2, etc.

[0051] In some embodiments, the mass ratio of the composite powder to the volume ratio of the organic matrix is ​​14:(3-7), such as 14:3, 14:3.2, 14:3.5, 14:3.8, 14:4, 14:4.5, 14:5, 14:5.5, 14:6, 14:6.5, 14:7, etc.

[0052] In some embodiments, the room temperature viscosity of the composite slurry is 2200-2700 mPa·s.

[0053] S4: Coat the composite slurry into a film and vacuum dry it to obtain the composite film;

[0054] In some embodiments, vacuum drying is performed sequentially at 55–65°C and 75–90°C. When using AIBN as an initiator, excessively high temperatures can cause AIBN decomposition, and the higher the temperature, the faster the decomposition rate. Therefore, vacuum drying at 55–65°C for 1–3 hours followed by vacuum drying at 75–90°C for 0.5–1.5 hours can effectively prevent initiator decomposition. Furthermore, during this process, the presence of a certain amount of organic solvent dilutes the decomposition of the initiator due to the solvent cage effect.

[0055] In some embodiments, the initiator is vacuum dried at 55–65°C for 1–3 hours, followed by vacuum drying at 75–90°C for 1 hour. During this process, without considering the solvent cage effect, the residual amount of initiator is still very high. However, the amount of organic solvent has been largely removed during this process. The initiator undergoes uniform crosslinking shrinkage during the subsequent hot pressing process without bubbling. Furthermore, the free radicals released by the initiator during the hot pressing process are sufficient to fully crosslink and initiate double bond polymerization chain reactions to form a three-dimensional crosslinked network. This confines the ceramic electrolyte particles and lithium salt to fixed sites, and the ion migration path does not become misaligned with the expansion / contraction during charging and discharging, thus reducing the rate of interfacial impedance growth.

[0056] S5: The composite membrane is hot-pressed in an inert atmosphere and then dried to obtain a solid electrolyte membrane.

[0057] In some embodiments, the specific method of step S5 may include: placing the dried composite membrane in an inert atmosphere, hot-pressing it at 80-120°C and 15-40 bar for 0.5-3 hours, and then vacuum drying it again to obtain a solid electrolyte membrane.

[0058] According to embodiments of the present invention, the solid electrolyte membrane prepared by the above method uses a boron-containing coupling agent to form covalent bonds on the surface of the ceramic electrolyte, and can also be free radical copolymerized with the organic matrix, effectively reducing the interfacial resistance, optimizing the particle size distribution, suppressing local current concentration, and simultaneously effectively improving the tensile strength and flexibility of the solid electrolyte membrane. Combined with the good ionic conductivity of the inorganic oxide solid electrolyte particles, the solid electrolyte membrane can simultaneously achieve the effect of high conductivity, low impedance, and high toughness.

[0059] In another aspect, the present invention provides a solid-state battery. According to an embodiment of the invention, the solid-state battery includes the solid electrolyte membrane described above, or includes a solid electrolyte membrane prepared by the aforementioned method. Therefore, the solid-state battery exhibits excellent battery performance. Those skilled in the art will understand that the solid-state battery possesses all the features and advantages of the solid electrolyte membrane described above, which will not be elaborated further here.

[0060] According to embodiments of the present invention, those skilled in the art will understand that, in addition to the aforementioned solid electrolyte membrane, the solid-state battery also includes the structures necessary for conventional solid-state batteries, such as positive electrode plates and negative electrode plates. The specific structures and materials used for the positive and negative electrode plates are not subject to special requirements, and those skilled in the art can flexibly select them according to actual needs, which will not be elaborated further here.

[0061] In another aspect, the present invention provides an electrical device. According to an embodiment of the invention, the electrical device includes the aforementioned solid-state battery. The battery of the electrical device has superior battery performance.

[0062] According to embodiments of the present invention, the electrical device is not limited to any particular device and can be any device that can use solid-state batteries, such as display devices like mobile phones, computers, televisions, and game consoles, as well as electric vehicles, toys, and other electrical devices.

[0063] Example

[0064] Example 1

[0065] S1: Take 150g of Li with a D50 of 0.2μm. 6.4 La3Zr2Al 0.2 O 12 The powder was added to 800 mL of 50% ethanol aqueous solution and sonicated for 20 min. Then, 1.5 g of Al2O3 powder with a D50 of 0.3 μm after high-energy ball milling was added and dispersed evenly to obtain a dispersion.

[0066] S2: After standing for 5 minutes, add 0.35 g of 4-vinylphenylboronic acid dissolved in 10 mL of anhydrous ethanol dropwise, reflux at 80 °C for 1 h, separate the solid, disperse the separated solid in anhydrous ethanol, sonicate at 40 kHz for 10 minutes, and vacuum dry to obtain composite powder.

[0067] S3: Dissolve 5.3g of LiTFSI and 1.5g of LiDFOB in 60mL of NMP solvent and stir magnetically for 10min to obtain a mixture. Add 70g of composite powder, 23mL of PEGDA, 1.6mL of trimethylolpropane triacrylate and 0.3g of AIBN to the mixture. Degas in a vacuum degassing machine at 30℃ and 80mbar for 30min to obtain a composite slurry with a solid content of 48wt% and a room temperature viscosity of 2400mPa·s.

[0068] S4: Coat the composite paste onto the PET release film, and vacuum dry it at 60°C for 2 hours and then at 80°C for 1 hour to obtain the composite film.

[0069] S5: The composite membrane is placed in a nitrogen atmosphere and pressed at 90℃ and 25 bar for 1.5 h, then vacuum dried at 110℃ for 1 h. The release membrane is then peeled off to obtain a solid electrolyte membrane with a thickness of 76 μm.

[0070] Example 2

[0071] S1: Take 150g of Li with a D50 of 0.22μm. 6.7 La3Zr2Al0.1 O 12 The powder was added to 800 mL of 50% ethanol aqueous solution and sonicated for 20 min. Then, 1.5 g of Al2O3 powder with a D50 of 0.4 μm after high-energy ball milling was added and dispersed evenly to obtain a dispersion.

[0072] S2: After standing for 5 minutes, add 0.25 g of 4-vinylphenylboronic acid dissolved in 10 mL of anhydrous ethanol dropwise, reflux at 80 °C for 1 h, separate the solid, disperse the separated solid in anhydrous ethanol, sonicate at 40 kHz for 10 minutes, and vacuum dry to obtain composite powder.

[0073] S3: Dissolve 5g of LiTFSI and 1.5g of LiDFOB in 60mL of NMP solvent and stir magnetically for 10min to obtain a mixture. Add 70g of composite powder, 23mL of PEGDA, 1.4mL of trimethylolpropane triacrylate and 0.3g of AIBN to the mixture. Degas in a vacuum degassing machine at 30℃ and 80mbar for 30min to obtain a composite slurry with a solid content of 47.8wt% and a room temperature viscosity of 2380mPa·s.

[0074] S4: Coat the composite paste onto the PET release film, and vacuum dry it at 60°C for 2 hours and then at 80°C for 1 hour to obtain the composite film.

[0075] S5: The composite membrane is placed in a nitrogen atmosphere and pressed at 90℃ and 25 bar for 1.5 h, then vacuum dried at 110℃ for 1 h. The release membrane is then peeled off to obtain a solid electrolyte membrane with a thickness of 74 μm.

[0076] Example 3

[0077] S1: Take 150g of Li with a D50 of 0.18μm. 6.1 La3Zr2Al 0.3 O 12 The powder was added to 800 mL of 50% ethanol aqueous solution and sonicated for 20 min. Then, 1.5 g of Al2O3 powder with a D50 of 0.34 μm after high-energy ball milling was added and dispersed evenly to obtain a dispersion.

[0078] S2: After standing for 5 minutes, add 0.3 g of 4-vinylphenylboronic acid dissolved in 10 mL of anhydrous ethanol dropwise, reflux at 80 °C for 1 h, separate the solid, disperse the separated solid in anhydrous ethanol, sonicate at 40 kHz for 10 minutes, and vacuum dry to obtain composite powder.

[0079] S3: Dissolve 5.5g of LiTFSI and 1.5g of LiDFOB in 60mL of NMP solvent and stir magnetically for 10min to obtain a mixture. Add 70g of composite powder, 23mL of PEGDA, 1.8mL of trimethylolpropane triacrylate and 0.3g of AIBN to the mixture. Degas in a vacuum degassing machine at 30℃ and 80mbar for 30min to obtain a composite slurry with a solid content of 48.1wt% and a room temperature viscosity of 2410mPa·s.

[0080] S4: Coat the composite paste onto the PET release film, and vacuum dry it at 60°C for 2 hours and then at 80°C for 1 hour to obtain the composite film.

[0081] S5: Place the composite membrane in a nitrogen atmosphere, press it at 100℃ and 30 bar for 1 hour, vacuum dry it at 110℃ for 1 hour, peel off the release membrane to obtain a solid electrolyte membrane with a thickness of 73 μm.

[0082] Example 4

[0083] S1: Take 150g of Li with a D50 of 0.16μm. 5.8 La3Zr2Al 0.4 O 12 The powder was added to 800 mL of 50% ethanol aqueous solution and sonicated for 20 min. Then, 1.5 g of Al2O3 powder with a D50 of 0.24 μm after high-energy ball milling was added and dispersed evenly to obtain a dispersion.

[0084] S2: After standing for 5 minutes, add 0.25 g of 4-vinylphenylboronic acid dissolved in 10 mL of anhydrous ethanol dropwise, reflux at 80 °C for 1 h, separate the solid, disperse the separated solid in anhydrous ethanol, sonicate at 40 kHz for 10 minutes, and vacuum dry to obtain composite powder.

[0085] S3: Dissolve 5.7g of LiTFSI and 1.5g of LiDFOB in 60mL of NMP solvent and stir magnetically for 10min to obtain a mixture. Add 70g of composite powder, 23mL of PEGDA, 2mL of trimethylolpropane triacrylate and 0.3g of AIBN to the mixture. Degas in a vacuum degasser at 30℃ and 80mbar for 30min to obtain a composite slurry with a solid content of 48.4wt% and a room temperature viscosity of 2456mPa·s.

[0086] S4: Coat the composite paste onto the PET release film, and vacuum dry it at 60°C for 2 hours and then at 80°C for 1 hour to obtain the composite film.

[0087] S5: The composite membrane is placed in a nitrogen atmosphere and pressed at 90℃ and 35 bar for 1.2 h, then vacuum dried at 110℃ for 1 h. The release membrane is then peeled off to obtain a solid electrolyte membrane with a thickness of 76 μm.

[0088] Example 5

[0089] S1: Take 150g of Li with a D50 of 0.32μm. 5.8 La3Zr2Al 0.4 O 12 The powder was added to 800 mL of 50% ethanol aqueous solution and sonicated for 20 min. Then, 1.5 g of Al2O3 powder with a D50 of 0.36 μm after high-energy ball milling was added and dispersed evenly to obtain a dispersion.

[0090] S2: After standing for 5 minutes, add 0.3 g of 4-vinylphenylboronic acid pinacol ester dissolved in 10 mL of anhydrous ethanol dropwise, reflux at 80 °C for 1 h, separate the solid, then disperse the separated solid in anhydrous ethanol, sonicate at 40 kHz for 10 min, and vacuum dry to obtain composite powder.

[0091] S3: Dissolve 5.3g of LiTFSI and 1.5g of LiDFOB in 60mL of NMP solvent and stir magnetically for 10min to obtain a mixture. Add 70g of composite powder, 23mL of PEGDA, 1.6mL of trimethylolpropane triacrylate and 0.3g of AIBN to the mixture. Degas in a vacuum degasser at 30℃ and 80mbar for 30min to obtain a composite slurry with a solid content of 48.1wt% and a room temperature viscosity of 2390mPa·s.

[0092] S4: Coat the composite paste onto the PET release film, and vacuum dry it at 60°C for 2 hours and then at 80°C for 1 hour to obtain the composite film.

[0093] S5: Place the composite membrane in a nitrogen atmosphere, press it at 85℃ and 30 bar for 1 hour, and vacuum dry it at 110℃ for 1 hour. Peel off the release membrane to obtain a solid electrolyte membrane with a thickness of 75 μm.

[0094] Example 6

[0095] S1: Take 150g of Li with a D50 of 0.26μm. 6.7 La3Zr2Al 0.1 O 12 The powder was added to 800 mL of 50% ethanol aqueous solution and sonicated for 20 min. Then, 1.5 g of Al2O3 powder with a D50 of 0.4 μm after high-energy ball milling was added and dispersed evenly to obtain a dispersion.

[0096] S2: After standing for 5 minutes, add 0.35 g of 4-vinylphenylboronic acid pinacol ester dissolved in 10 mL of anhydrous ethanol dropwise, reflux at 80 °C for 1 h, separate the solid, disperse the separated solid in anhydrous ethanol, sonicate at 40 kHz for 10 min, and vacuum dry to obtain composite powder.

[0097] S3: Dissolve 5g of LiTFSI and 1.5g of LiDFOB in 60mL of NMP solvent and stir magnetically for 10min to obtain a mixture. Add 70g of composite powder, 23mL of PEGDA, 1.4mL of trimethylolpropane triacrylate and 0.3g of AIBN to the mixture. Degas in a vacuum degassing machine at 30℃ and 80mbar for 30min to obtain a composite slurry with a solid content of 48.0wt% and a room temperature viscosity of 2370mPa·s.

[0098] S4: Coat the composite paste onto the PET release film, and vacuum dry it at 60°C for 2 hours and then at 80°C for 1 hour to obtain the composite film.

[0099] S5: The composite membrane is placed in a nitrogen atmosphere and pressed at 115℃ and 25 bar for 2 hours, then vacuum dried at 110℃ for 1 hour. The release membrane is then peeled off to obtain a solid electrolyte membrane with a thickness of 73 μm.

[0100] Example 7

[0101] S1: Take 150g of Li with a D50 of 0.2μm. 6.4 La3Zr2Al 0.2 O 12 The powder was added to 800 mL of 50% ethanol aqueous solution and sonicated for 20 min. Then, 1.5 g of Al2O3 powder with a D50 of 0.36 μm after high-energy ball milling was added and dispersed evenly to obtain a dispersion.

[0102] S2: After standing for 5 minutes, add 0.25 g of 4-vinylphenylboronic acid dissolved in 10 mL of anhydrous ethanol dropwise, reflux at 80 °C for 1 h, separate the solid, disperse the separated solid in anhydrous ethanol, sonicate at 40 kHz for 10 minutes, and vacuum dry to obtain composite powder.

[0103] S3: Dissolve 5.4g of LiTFSI and 1.5g of LiDFOB in 60mL of NMP solvent and stir magnetically for 10min to obtain a mixture. Add 70g of composite powder, 23mL of PEGDA, 1.7mL of trimethylolpropane triacrylate and 0.3g of AIBN to the mixture. Degas in a vacuum degassing machine at 30℃ and 80mbar for 30min to obtain a composite slurry with a solid content of 48.0wt% and a room temperature viscosity of 2420mPa·s.

[0104] S4: Coat the composite paste onto the PET release film, and vacuum dry it at 60°C for 2 hours and then at 80°C for 1 hour to obtain the composite film.

[0105] S5: Place the composite membrane in a nitrogen atmosphere, press it at 90℃ and 30 bar for 1 hour, and vacuum dry it at 110℃ for 1 hour. Peel off the release membrane to obtain a solid electrolyte membrane with a thickness of 78 μm.

[0106] Example 8

[0107] S1: Take 150g of Li with a D50 of 0.24μm. 6.1 La3Zr2Al 0.3 O 12 The powder was added to 800 mL of 50% ethanol aqueous solution and sonicated for 20 min. Then, 1.5 g of Al2O3 powder with a D50 of 0.36 μm after high-energy ball milling was added and dispersed evenly to obtain a dispersion.

[0108] S2: After standing for 5 minutes, add 0.3 g of 4-vinylphenylboronic acid dissolved in 10 mL of anhydrous ethanol dropwise, reflux at 80 °C for 1 h, separate the solid, disperse the separated solid in anhydrous ethanol, sonicate at 40 kHz for 10 minutes, and vacuum dry to obtain composite powder.

[0109] S3: Dissolve 5.6g of LiTFSI and 1.5g of LiDFOB in 60mL of NMP solvent and stir magnetically for 10min to obtain a mixture. Add 70g of composite powder, 23mL of PEGDA, 1.9mL of trimethylolpropane triacrylate and 0.3g of AIBN to the mixture. Degas in a vacuum degassing machine at 30℃ and 80mbar for 30min to obtain a composite slurry with a solid content of 48.5wt% and a room temperature viscosity of 2470mPa·s.

[0110] S4: Coat the composite paste onto the PET release film, and vacuum dry it at 60°C for 2 hours and then at 80°C for 1 hour to obtain the composite film.

[0111] S5: The composite membrane is placed in a nitrogen atmosphere and pressed at 100℃ and 25 bar for 1 hour, then vacuum dried at 110℃ for 1 hour. The release membrane is then peeled off to obtain a solid electrolyte membrane with a thickness of 77 μm.

[0112] Example 9

[0113] The preparation steps are basically the same as in Example 1, except that in step S2, 0.35 g of 2-vinyl-1,3,2-dioxoborane dissolved in 10 mL of anhydrous ethanol is added dropwise.

[0114] Example 10

[0115] The preparation steps are basically the same as in Example 1, except that in step S2, 0.05 g of 4-vinylphenylboronic acid dissolved in 10 mL of anhydrous ethanol is added dropwise.

[0116] Example 11

[0117] The preparation steps are basically the same as in Example 1, except that in step S2, 0.75g of 4-vinylphenylboronic acid dissolved in 10mL of anhydrous ethanol is added dropwise.

[0118] Example 12

[0119] The preparation steps are basically the same as in Example 1, except that in step S1, the particle size D50 of Al2O3 powder is 0.8 μm.

[0120] Example 13

[0121] The preparation steps are basically the same as in Example 1, except that in step S4, a composite slurry is coated on the PET release film and vacuum dried at 70°C for 3 hours in one go to obtain the composite film.

[0122] Comparative Example 1

[0123] The preparation steps are basically the same as in Example 1, except that in step S, 0.35g of vinyltrimethoxysilane (coupling agent) dissolved in 10mL of anhydrous ethanol is added dropwise.

[0124] Comparative Example 2

[0125] The preparation steps are basically the same as in Example 1, except that in step S1, the inorganic oxide solid electrolyte particles used are Li7La3Zr2O. 12 .

[0126] The solid electrolyte membranes prepared in Examples 1-13 and Comparative Examples 1-2 were respectively made into discs with a diameter of 10 mm. In a drying room, they were clamped between two blocking electrodes, installed in a 2032 coin cell case, and a constant surface pressure of 1.5-2 MPa was applied. Using an electrochemical workstation, impedance tests were performed at 25°C with an AC amplitude of 10 mV and a frequency range of 1 MHz-1 Hz. The room temperature ionic conductivity was calculated, and the test results are shown in Table 1.

[0127] The solid electrolyte membranes prepared in Examples 1-13 and Comparative Examples 1-2 were fabricated into discs with a diameter of 14 mm. Two lithium metal foils, each 50 μm thick and 14 mm in diameter, were respectively bonded to both sides of the electrolyte disc to form a Li│electrolyte│Li symmetrical structure. This structure was then installed into a 2032 coin cell casing, and a constant surface pressure of 1.5–2 MPa was applied. A battery testing system was used at a constant current density of 0.1 mA / cm². -2 Under the conditions of 25℃, polarization for 10 min, and sampling frequency of 1Hz, the interface impedance was calculated, and the test results are shown in Table 1.

[0128] The tensile strength and elongation at break of the solid electrolyte membranes in Examples 1-13 and Comparative Examples 1-3 were tested using GB / T 1040. The test results are shown in Table 1.

[0129] Table 1

[0130]

[0131] Based on the performance test table, we can see that:

[0132] Compared with Comparative Examples 1-2, the solid electrolyte membranes of Examples 1-13 exhibit higher ionic conductivity, lower interfacial impedance, and higher tensile strength and elongation at break. As shown in the table, if a conventional silane coupling agent (Comparative Example 1) is used, the Si-OH groups formed after hydrolysis can only undergo single-point condensation with the hydroxyl groups on the surface of the solid electrolyte, which is insufficient to produce an anchoring effect. Furthermore, it easily forms a low-density coating layer, hindering short-range lithium-ion migration. On the other hand, the silane layer is only connected to the organic matrix by van der Waals forces, resulting in large interfacial voids and a tendency to generate impedance. In contrast to Example 2, the solid electrolytes with higher ionic conductivity in these examples, combined with a boron-containing coupling agent and a flexible network, show promise in resolving the contradiction between flexibility and interfacial impedance. LLZAO provides bulk ion channels, forming connections between grain boundaries and the polymer, thereby improving ionic conductivity, interfacial impedance, and mechanical properties such as tensile strength and elongation at break.

[0133] Compared to Examples 10-13, the solid electrolyte membranes of Examples 1-9 exhibit higher ionic conductivity, lower interfacial impedance, and higher tensile strength and elongation at break. Examples 10 and 11 demonstrate that incomplete or excessive coating of electrolyte particles can also affect performance. Example 12 shows that the particle size distribution of the inorganic oxide filler and electrolyte particles also affects performance; if multiple particle sizes fall within different ranges with a significant difference, the intercalation effect will be affected. Lithium vacancy concentration and interfacial effects substantially influence ionic conductivity and interfacial impedance. Example 13 shows that the drying process for forming the composite membrane primarily determines the residual amount of NMP solvent, which in turn affects the performance of the electrolyte membrane.

[0134] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0135] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A solid state electrolyte membrane, characterized by, Comprises: Inorganic oxide solid electrolyte particles, inorganic oxide filler, coupling agent, organic matrix, and lithium salt, wherein, The inorganic oxide solid electrolyte particles are Li 7-3x La3Zr2Al x O 12 wherein 0.1≤x≤0.4; The coupling agent is an unsaturated compound containing boron, and its chemical structural formula is R 1 -B(OR 2 )2, wherein R 1 represents a hydrocarbon group containing an unsaturated bond with carbon atoms numbering from 2 to 12, or a group in which part or all of the hydrogen atoms in the hydrocarbon group are replaced by any one of halogen, alkoxy, or aryl; R 2 represents a hydrogen atom, an alkyl group with carbon atoms numbering from 1 to 6, an alkenyl group with carbon atoms numbering from 2 to 6, an alkynyl group with carbon atoms numbering from 2 to 6, an aryl group, or a boron-containing heterocyclic structure formed by two R 2 groups and the boron atom.

2. The solid-state electrolyte film of claim 1, wherein, R 1 represents an alkenyl group or a hydrocarbyl-substituted aryl group, R 2 represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or two R 2 forms a boron-containing heterocyclic structure having a total number of atoms of 5 to 7 with the boron atom, Optionally, the coupling agent comprises at least one of 4-vinylphenylboronic acid, 3-vinylphenylboronic acid, 2-vinylphenylboronic acid, 4-vinylphenylboronic acid pinacol ester, 3-vinylphenylboronic acid pinacol ester, 2-vinylphenylboronic acid pinacol ester, 2-vinyl-1,3,2-dioxaborolane, 2-isopropenyl-1,3,2-dioxaborinane.

3. The solid-state electrolyte film of claim 1, wherein, The difference between the particle size D50 of the inorganic oxide solid electrolyte particles and the particle size D50 of the inorganic oxide filler is 0-0.2 μm, and the particle size D50 of the inorganic oxide solid electrolyte particles and the particle size D50 of the inorganic oxide filler are each less than or equal to 0.5 μm.

4. The solid-state electrolyte film according to any one of claims 1 to 3, characterized by Also meet at least one of the following conditions: The mass ratio of the inorganic oxide solid electrolyte particles to the coupling agent is 100:(0.15-0.35); The mass ratio of the inorganic oxide solid electrolyte particles to the inorganic oxide filler is 100:(0.3-1.5).

5. The solid-state electrolyte film according to any one of claims 1 to 3, characterized by The organic matrix comprises polyether monomer and crosslinking agent, and the mass ratio of the polyether monomer to the crosslinking agent is 100:(2-10).

6. The solid electrolyte film according to claim 5, wherein The inorganic oxide filler comprises at least one of Al2O3, ZrO2, TiO2; Optionally, the polyether monomer comprises at least one of polyethylene glycol dimethacrylate, methoxypolyethylene glycol acrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, polyethylene glycol hydroxyethyl methacrylate, ethoxylated trimethylolpropane triacrylate; Optionally, the crosslinking agent comprises at least one of pentaerythritol tetraacrylate, di-trimethylolpropane tetraacrylate, trimethylolpropane triacrylate, triallyl isocyanurate, pentaerythritol triacrylate, tetramethylolmethane tetraacrylate; Optionally, the lithium salt can be selected from at least one of LiPF6, LiFSI, LiTFSI, LiBOB, LiDFOB, LiODFB, LiBF4, LiClO4.

7. A method for producing the solid-state electrolyte film according to any one of claims 1 to 6, characterized by, Comprises: Uniformly dispersing inorganic oxide solid electrolyte particles and inorganic oxide filler in a solvent to obtain a dispersion liquid; Adding a coupling agent to the dispersion liquid, and obtaining a composite powder by refluxing and separating; Mixing the composite powder, lithium salt, organic matrix, and initiator in an organic solvent and vacuum degassing to obtain a composite slurry; Coating the composite slurry into a film and vacuum drying to obtain a composite film; Hot pressing the composite film in an inert atmosphere, and drying to obtain the solid electrolyte film.

8. The method of claim 7, wherein, Meet at least one of the following conditions: The mass ratio of the composite powder to the lithium salt is 14:(1-2); The mass ratio of the mass of the composite powder to the volume of the organic matrix is 14:(3-7); The room temperature viscosity of the composite slurry is 2200-2700 mPa·s; The vacuum drying is performed at 55-65°C and 75-90°C in sequence.

9. A solid state battery, characterized by The solid-state electrolyte film according to any one of claims 1 to 6, or the solid-state electrolyte film prepared by the method according to claim 7 or 8.

10. An electric device, characterized by The solid-state battery according to claim 9.

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