Solid-state electrolyte, preparation method therefor and use thereof

Abstract

The present invention belongs to the field of batteries, specifically disclosed are a solid-state electrolyte, a preparation method therefor and a use thereof. The solid-state electrolyte contains a biomimetic material, an electrolyte salt, and a plasticizer. The biomimetic material is loaded with the electrolyte salt and the plasticizer. The biomimetic material comprises a monocyclic aromatic compound and a triazine nitrogen-containing heterocyclic compound. The monocyclic aromatic compound and the triazine nitrogen-containing heterocyclic compound are connected through hydrogen bonds. The biomimetic material has nanochannels with a diameter of 0.3-1 nm. In the solid-state electrolyte of the present invention, the monocyclic aromatic compound and the triazine nitrogen-containing heterocyclic compound are assembled through hydrogen bonds to form a biomimetic material having nanofluid transport channels with a diameter of 0.3-1 nm, thereby enabling rapid ion conduction of metal cations under nanofluid control, such that a solid-state battery containing the solid-state electrolyte of the present invention has a room-temperature lithium-ion conductivity of up to 17 mS / cm, a transference number of up to 0.7-0.8, and a voltage window of up to 4.5 V.

Description

A solid electrolyte, its preparation method and application Technical Field

[0001] This invention belongs to the field of batteries, specifically relating to a solid electrolyte, its preparation method, and its application. Background Technology

[0002] Researchers have discovered that channel proteins on biological membranes possess nanofluidic ion transport mechanisms, which can significantly improve ion transport efficiency. Furthermore, the interactions between the binding sites on the channel proteins, ions, and plasticizer molecules play a crucial role in the ion transport behavior within the channels. Scientists have utilized these phenomena to develop a series of biomimetic nanochannel systems, achieving significant breakthroughs in life sciences, salinity gradient power generation, and sensing devices. However, this type of biomimetic ion transport design has not yet been applied to solid-state ion conductors, solid-state electrolytes, and solid-state batteries.

[0003] Nanofluidization is an ultrafast ion transport phenomenon that occurs under nanoscale confinement conditions within nanopores smaller than 100 nm. Its key characteristics include ion conduction speeds approaching those of liquid electrolytes and high ion selectivity. The principle behind nanofluidization is the manipulation of the nanopore size and surface chemistry of the material. When the nanopore size is smaller than the Debye flask size of the electrolyte being conducted, the surface charge repels ions of the same charge and attracts ions of opposite charge, forming a rapidly conducting, highly selective ion flow. However, current technology has not yet applied the nanofluidization principle to solid-state electrolytes.

[0004] Existing technology discloses a mussel-inspired organic polymer solid electrolyte and solid-state battery. This technology mimics the structure of mussels to prepare the biomimetic polymer. By introducing a dopamine structure into the main chain of polyethylene oxide, chain segment crystallization is prevented, thereby improving the ionic conductivity and mechanical strength of the mussel-inspired polymer. Experiments have yielded lithium-ion conductivity between 0.09 and 0.3 mS / cm, and this material has been used in solid-state lithium batteries. However, this biomimetic design does not involve the research and design of nanocurrent phenomena, and the lithium-ion conductivity is relatively low. Therefore, it is necessary to redesign organic biomimetic materials with better performance based on the nanocurrent principle.

[0005] In addition, the room temperature lithium-ion conductivity of organic solid electrolytes in the prior art is often below 0.1 mS / cm, the lithium-ion transference number is below 0.3, and they have poor selectivity. They are mainly used for conducting anions, and the antioxidant potential of the electrolyte is below 4.2V, which makes them unsuitable for high-voltage cathode materials. Summary of the Invention

[0006] In order to overcome at least one of the technical problems existing in the prior art, one of the objectives of the present invention is to provide a solid electrolyte.

[0007] The second objective of this invention is to provide a method for preparing a solid electrolyte.

[0008] The third objective of this invention is to provide a solid-state battery.

[0009] The fourth objective of this invention is to provide the application of the above-mentioned solid electrolyte and / or solid battery in electronic products.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0011] A first aspect of the present invention provides a solid electrolyte comprising a biomimetic material, an electrolyte salt, and a plasticizer; wherein the biomimetic material is loaded with the electrolyte salt and the plasticizer; wherein the biomimetic material comprises a monocyclic aromatic compound and a triazine nitrogen-containing heterocyclic compound; wherein the monocyclic aromatic compound and the triazine nitrogen-containing heterocyclic compound are linked by hydrogen bonds; and wherein the biomimetic material has nanopores with a diameter of 0.3 to 1 nm.

[0012] This invention utilizes the interaction between functional groups, electrolyte salts, and plasticizers in biomimetic materials to regulate the interaction force between nanochannels in biomimetic materials and metal ions in electrolyte salts. This ensures that the dissociation energy of metal ions with plasticizers and the binding energy of metal ions with functional groups are matched, thereby reducing the activation energy of metal ions in electrolyte salts within nanopores and achieving rapid ion conduction under nanofluid control.

[0013] In one embodiment of the present invention, the molar ratio of the monocyclic aromatic compound and the triazine nitrogen-containing heterocyclic compound is 1:(0.8-1.2).

[0014] In one embodiment of the present invention, the diameter of the nanopores in the biomimetic material is 0.3 to 1 nm. When the diameter of the nanopores in the biomimetic material is within 0.3 to 1 nm, nanofluid channels are formed within the biomimetic material, allowing cations in the electrolyte salt, such as lithium ions, sodium ions, or potassium ions, to be transported ultrafastly within the biomimetic material, thereby forming a nanofluid.

[0015] In one embodiment of the present invention, the monocyclic aromatic compound contains a functional group selected from at least one of oxygen-containing functional groups, nitrogen-containing functional groups, sulfur-containing functional groups, and halogens.

[0016] In one embodiment of the present invention, the triazine-type nitrogen-containing heterocyclic compound contains a functional group selected from at least one of oxygen-containing functional groups, nitrogen-containing functional groups, sulfur-containing functional groups, and halogens.

[0017] In one embodiment of the present invention, the oxygen-containing functional group includes at least one selected from carboxyl, hydroxyl, and carbonyl groups.

[0018] In one embodiment of the present invention, the sulfur-containing functional group includes at least one of sulfonic acid group, mercapto group, and sulfinyl group.

[0019] In one embodiment of the present invention, the nitrogen-containing functional group includes at least one selected from nitro, amino, and amide groups.

[0020] In some embodiments of the present invention, the halogen is selected from at least one of F, Cl, Br, and I.

[0021] In some embodiments of the present invention, the monocyclic aromatic compound is selected from at least one of pyromellitic acid, pyromellitic acid, phloroglucinol, and terephthalamide.

[0022] In some embodiments of the present invention, the triazine nitrogen-containing heterocyclic compound is selected from at least one of melamine, 2,4,6-tris(trifluoromethyl)-1,3,5-triazine, 1,3,5-triacryloylhexahydro-1,3,5-triazine, and cyanuric chloride.

[0023] This invention constructs nanofluid transport channels with a diameter between 0.3 and 1 nm by adjusting the functional groups in monocyclic aromatic compounds and triazine nitrogen-containing heterocyclic compounds and through material screening. By adjusting the types of functional groups in both compounds, the surface chemistry and charge state of the resulting biomimetic material's nanofluid transport channels can be controlled.

[0024] In some embodiments of the present invention, the electrolyte salt is selected from at least one of lithium chloride, lithium bromide, lithium bis(trifluoromethylsulfonyl)imide, and lithium bis(fluorosulfonyl)imide.

[0025] In some embodiments of the present invention, the electrolyte salt is selected from at least one of sodium chloride, sodium bromide, sodium bis(trifluoromethylsulfonyl)imide, and sodium bis(fluorosulfonyl)imide.

[0026] In some embodiments of the present invention, the electrolyte salt is selected from at least one of potassium chloride, potassium bromide, potassium bis(trifluoromethylsulfonyl)imide, and potassium bis(fluorosulfonyl)imide.

[0027] In some embodiments of the present invention, the plasticizer comprises at least one of acetonitrile, fluoroacetonitrile, succinic anionyl nitrile, water, ethylene carbonate, N-methylpyrrolidone, N,N-dimethylformamide, methyl methacrylate, ethylene carbonate, propylene carbonate, diethyl carbonate, dimethyl ether, diethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxane, tetrahydrofuran, toluene, ethanol, ethyl acetate, propyl acetate, fluoroethylene carbonate, methyl trifluoroethyl carbonate, hydrofluoroether, imidazole ionic liquids, pyridine ionic liquids, and quaternary ammonium ionic liquids. The plasticizer in the present invention mainly serves as a carrier for the electrolyte salt, dissociating the electrolyte salt and introducing it into the biomimetic material. Before subsequent film formation, the plasticizer partially volatilizes, leaving a small amount of plasticizer in the solid electrolyte to improve the mechanical properties of the solid electrolyte membrane.

[0028] In some embodiments of the present invention, the plasticizer comprises plasticizing component A and plasticizing component B in a volume ratio of (1-9):1. Plasticizing component A is selected from at least one of acetonitrile, fluoroacetonitrile, succinic anionyl nitrile, water, N-methylpyrrolidone, and N,N-dimethylformamide. Plasticizing component B is selected from at least one of ethylene carbonate, acetonitrile, methyl carbonate, ethylene carbonate, propylene carbonate, diethyl carbonate, dimethyl ether, diethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxane, tetrahydrofuran, toluene, ethanol, ethyl acetate, propyl acetate, fluoroethylene carbonate, methyltrifluoroethyl carbonate, hydrofluoroether, imidazole ionic liquids, pyridine ionic liquids, and quaternary ammonium ionic liquids. Plasticizing component A and plasticizing component B are not the same.

[0029] In some embodiments of the present invention, the plasticizer comprises acetonitrile and ethylene carbonate in a volume ratio of (1-9):1.

[0030] In some embodiments of the present invention, the plasticizer comprises water and acetonitrile in a volume ratio of (1 to 9):1.

[0031] In some embodiments of the present invention, the plasticizer comprises N,N-dimethylformamide and acetonitrile in a volume ratio of (1-9):1.

[0032] This invention adjusts the types of plasticizers and electrolyte salts within the nanopores to regulate the interaction forces between metal ions (e.g., lithium ions, sodium ions, or potassium ions) and the functional groups of the nanofluid channels in biomimetic materials. This makes the dissociation energy between metal ions in the electrolyte salt and plasticizer molecules close to the binding energy between metal ions in the electrolyte salt and functional groups in the biomimetic material, thereby reducing the activation energy for metal ions in the electrolyte salt to transfer into the channels and achieving rapid ion conduction under nanofluid control.

[0033] A second aspect of the present invention provides a method for preparing the solid electrolyte described in the first aspect of the present invention, comprising the following steps:

[0034] S1: Biomimetic materials are obtained by assembling monocyclic aromatic compounds and triazine nitrogen-containing heterocyclic compounds in a solvent;

[0035] S2: Load the biomimetic material with electrolyte salt and plasticizer, and then form a film to obtain the solid electrolyte.

[0036] In some embodiments of the present invention, step S1 is: heating and mixing a monocyclic aromatic compound, a triazine nitrogen-containing heterocyclic compound, and a solvent, and then precipitating the mixture to obtain a biomimetic material.

[0037] In some embodiments of the present invention, the solvent in step S1 is dimethyl sulfoxide.

[0038] In some embodiments of the present invention, the heating temperature is 50 to 100°C.

[0039] In some embodiments of the present invention, the mixing time is 0.5 to 2 hours.

[0040] In some embodiments of the present invention, the mass ratio of the monocyclic aromatic compound to the solvent is 15 to 20:1.

[0041] In some embodiments of the present invention, the precipitation step is to add a precipitation solvent to precipitate the product.

[0042] In some embodiments of the present invention, the precipitation solvent is selected from at least one of water, ethanol, acetone, and acetonitrile.

[0043] In some embodiments of the present invention, the mass ratio of the precipitating solvent to the triazine nitrogen-containing heterocyclic compound is 15 to 20:1.

[0044] In some embodiments of the present invention, the film-forming step employs isostatic pressing or dry film-forming.

[0045] In some embodiments of the present invention, the pressure of the isostatic pressing film formation step is 30-50 MPa.

[0046] In some embodiments of the present invention, the holding time of the isostatic pressing film formation step is 1 to 10 minutes.

[0047] In some embodiments of the present invention, the dry film-forming step is as follows: grinding and mixing the solid electrolyte with a binder, and then forming a film by rolling or coating.

[0048] In some embodiments of the present invention, the mass ratio of the solid electrolyte to the binder is (4-49):1.

[0049] In some embodiments of the present invention, the adhesive is selected from at least one of polytetrafluoroethylene, polyvinylidene fluoride, and styrene-butadiene rubber.

[0050] In some embodiments of the present invention, step S2 is: mixing the electrolyte salt and the plasticizer to obtain a mixed solution; immersing the biomimetic material in the mixed solution to allow the electrolyte salt and plasticizer in the mixed solution to enter the biomimetic material, and then forming a film to obtain the solid electrolyte.

[0051] In some embodiments of the present invention, the concentration of the electrolyte salt in the mixed solution is 0.8 to 1.2 mol / L.

[0052] In some embodiments of the present invention, the number of soaking times is 1 to 5.

[0053] A third aspect of the present invention provides a solid-state battery comprising the solid-state electrolyte described in the first aspect of the present invention.

[0054] The fourth aspect of the present invention provides the application of the solid electrolyte described in the first aspect of the present invention and / or the solid battery described in the third aspect of the present invention in electronic products.

[0055] The beneficial effects of this invention are as follows: the monocyclic aromatic compounds and triazine nitrogen-containing heterocyclic compounds in the solid electrolyte of this invention are assembled by hydrogen bonds into a biomimetic material with nanocurrent transport channels having a diameter of 0.3 to 1 nm, which can realize rapid ion conduction of metal cations (such as lithium ions, sodium ions or potassium ions) under nanocurrent control, so that the solid battery containing the solid electrolyte of this invention has a room temperature lithium ion conductivity of up to 17 mS / cm, a mobility coefficient of up to 0.7 to 0.8, and a voltage window of up to 4.5 V.

[0056] The preparation method of this invention assembles biomimetic materials from monocyclic aromatic compounds and triazine nitrogen-containing heterocyclic compounds. The preparation method is simple, the raw materials are widely available, no by-products are generated during the preparation process, and the resulting solid electrolyte has high ionic conductivity and mobility coefficient. Attached Figure Description

[0057] Figure 1 is a physical image of the solid electrolyte membrane in Example 1.

[0058] Figure 2 is a transmission electron microscope image of the biomimetic material in Example 1.

[0059] Figure 3 is a high-resolution transmission electron microscope image of the biomimetic material in Example 1.

[0060] Figure 4 shows the room temperature ionic conductivity of the solid electrolyte membrane in Example 1.

[0061] Figure 5 shows the room temperature charge-discharge performance test of the solid electrolyte membrane in Example 1.

[0062] Figure 6 shows the room temperature rate performance test of the solid electrolyte membrane in Example 1. Detailed Implementation

[0063] The specific implementation of the present invention will be further described in detail below with reference to the accompanying drawings and examples, but the implementation and protection of the present invention are not limited thereto. It should be noted that any processes not specifically described in detail below are those that can be implemented or understood by those skilled in the art by referring to the prior art. Reagents or instruments used without specified manufacturers are all conventional products that can be purchased commercially.

[0064] In some embodiments of the present invention, the present invention provides a solid electrolyte containing biomimetic materials, electrolyte salts, and plasticizers; the biomimetic materials are loaded with electrolyte salts and plasticizers; the biomimetic materials include monocyclic aromatic compounds and triazine nitrogen-containing heterocyclic compounds; the monocyclic aromatic compounds and triazine nitrogen-containing heterocyclic compounds are linked by hydrogen bonds; the biomimetic materials have nanopores with a diameter of 0.3 to 1 nm.

[0065] In some embodiments of the present invention, the molar ratio of the monocyclic aromatic compound and the triazine nitrogen-containing heterocyclic compound is 1:(0.8 to 1.2), for example, it can be selected from 1:0.8, 1:0.9, 1:1, 1:1.1, 1:1.2.

[0066] In some embodiments of the present invention, the diameter of the nanopores in the biomimetic material is 0.3–1 nm, for example, selectable from 0.3 nm, 0.4 nm, 0.5 nm, 0.6 nm, 0.7 nm, 0.8 nm, 0.9 nm, and 1 nm. When the diameter of the nanopores in the biomimetic material is within 0.3–1 nm, nanocurrent channels are formed within the biomimetic material, allowing cations in the electrolyte salt, such as lithium ions, sodium ions, or potassium ions, to be transported ultrafastly within the biomimetic material, thereby forming a nanocurrent.

[0067] In some embodiments of the present invention, the monocyclic aromatic compound contains a functional group selected from at least one of oxygen-containing functional groups, nitrogen-containing functional groups, sulfur-containing functional groups, and halogens.

[0068] In some embodiments of the present invention, the triazine nitrogen-containing heterocyclic compounds contain a functional group selected from at least one of oxygen-containing functional groups, nitrogen-containing functional groups, sulfur-containing functional groups, and halogens.

[0069] In some embodiments of the present invention, the oxygen-containing functional group includes at least one of carboxyl, hydroxyl, and carbonyl groups.

[0070] In some embodiments of the present invention, the sulfur-containing functional group includes at least one of sulfonic acid group, mercapto group, and sulfinyl group.

[0071] In some embodiments of the present invention, the nitrogen-containing functional group includes at least one of nitro, amino, and amide groups.

[0072] In some embodiments of the present invention, the halogen is selected from at least one of F, Cl, Br, and I.

[0073] In some embodiments of the present invention, the monocyclic aromatic compound is selected from at least one of pyromellitic acid, pyromellitic acid, phloroglucinol, and terephthalamide.

[0074] In some embodiments of the present invention, the triazine nitrogen-containing heterocyclic compound is selected from at least one of melamine, 2,4,6-tris(trifluoromethyl)-1,3,5-triazine, 1,3,5-triacryloylhexahydro-1,3,5-triazine, and cyanuric chloride.

[0075] This invention constructs nanofluid transport channels with a diameter between 0.3 and 1 nm by adjusting the functional groups in monocyclic aromatic compounds and triazine nitrogen-containing heterocyclic compounds and through material screening. By adjusting the types of functional groups in both compounds, the surface chemistry and charge state of the resulting biomimetic material's nanofluid transport channels can be controlled.

[0076] In some embodiments of the present invention, the electrolyte salt is selected from at least one of lithium chloride, lithium bromide, lithium bis(trifluoromethylsulfonyl)imide, and lithium bis(fluorosulfonyl)imide.

[0077] In some embodiments of the present invention, the electrolyte salt is selected from at least one of sodium chloride, sodium bromide, sodium bis(trifluoromethylsulfonyl)imide, and sodium bis(fluorosulfonyl)imide.

[0078] In some embodiments of the present invention, the electrolyte salt is selected from at least one of potassium chloride, potassium bromide, potassium bis(trifluoromethylsulfonyl)imide, and potassium bis(fluorosulfonyl)imide.

[0079] In some embodiments of the present invention, the plasticizer comprises at least one selected from acetonitrile, fluoroacetonitrile, succinic anion, water, ethylene carbonate, N-methylpyrrolidone, N,N-dimethylformamide, methyl carbonate, ethylene carbonate, propylene carbonate, diethyl carbonate, dimethyl ether, diethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxane, tetrahydrofuran, toluene, ethanol, ethyl acetate, propyl acetate, fluoroethylene carbonate, methyltrifluoroethyl carbonate, hydrofluoroether, imidazole ionic liquid, pyridine ionic liquid, and quaternary ammonium ionic liquid.

[0080] In some embodiments of the present invention, the plasticizer comprises plasticizing component A and plasticizing component B in a volume ratio of (1-9):1, for example, the volume ratio may be selected from 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, or 9:1; plasticizing component A is selected from at least one of acetonitrile, fluoroacetonitrile, succinic anionyl nitrile, water, N-methylpyrrolidone, and N,N-dimethylformamide; plasticizing component B is selected from at least one of ethylene carbonate, acetonitrile, methyl methacrylate, ethylene carbonate, propylene carbonate, diethyl carbonate, dimethyl ether, diethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxane, tetrahydrofuran, toluene, ethanol, ethyl acetate, propyl acetate, fluoroethylene carbonate, methyl trifluoroethyl carbonate, hydrofluoroether, imidazole ionic liquids, pyridine ionic liquids, and quaternary ammonium ionic liquids, and plasticizing components A and B are not the same.

[0081] In some embodiments of the present invention, the plasticizer comprises acetonitrile and ethylene carbonate in a volume ratio of (1 to 9):1, for example, selected from 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, or 9:1.

[0082] In some embodiments of the present invention, the plasticizer comprises water and acetonitrile in a volume ratio of (1 to 9):1, for example, the volume ratio may be selected from 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, or 9:1.

[0083] In some embodiments of the present invention, the plasticizer comprises N,N-dimethylformamide and acetonitrile in a volume ratio of (1 to 9):1, for example, the volume ratio may be selected from 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, or 9:1.

[0084] This invention adjusts the types of plasticizers and electrolyte salts within the nanopores to regulate the interaction forces between metal ions (e.g., lithium ions, sodium ions, or potassium ions) and the functional groups of the nanofluid channels in biomimetic materials. This makes the dissociation energy between metal ions in the electrolyte salt and plasticizer molecules close to the binding energy between metal ions in the electrolyte salt and functional groups in the biomimetic material, thereby reducing the activation energy for metal ions in the electrolyte salt to transfer into the channels and achieving rapid ion conduction under nanofluid control.

[0085] In some embodiments of the present invention, the present invention also provides a method for preparing a solid electrolyte, comprising the following steps:

[0086] S1: Biomimetic materials are obtained by assembling monocyclic aromatic compounds and triazine nitrogen-containing heterocyclic compounds in a solvent;

[0087] S2: Load electrolyte salts and plasticizers onto biomimetic materials, then form a film to obtain a solid electrolyte.

[0088] In some embodiments of the present invention, step S1 is: heating and mixing a monocyclic aromatic compound, a triazine nitrogen-containing heterocyclic compound, and a solvent, and then precipitating the mixture to obtain a biomimetic material.

[0089] In some embodiments of the present invention, the solvent in step S1 is dimethyl sulfoxide.

[0090] In some embodiments of the present invention, the heating temperature is 50–100°C. In some specific embodiments of the present invention, the heating temperature can be 50°C, 60°C, 70°C, 80°C, 90°C, or 100°C.

[0091] In some embodiments of the present invention, the mixing time is 0.5 to 2 hours. In some specific embodiments of the present invention, the mixing time can be 0.5 hours, 1 hour, 1.5 hours, or 2 hours.

[0092] In some embodiments of the present invention, the mass ratio of the monocyclic aromatic compound to the solvent is 15 to 20:1. In some specific embodiments of the present invention, the mass ratio of the monocyclic aromatic compound to the solvent can be 15:1, 16:1, 17:1, 18:1, 19:1, or 20:1.

[0093] In some embodiments of the present invention, the precipitation step involves adding a precipitation solvent to precipitate the product.

[0094] In some embodiments of the present invention, the precipitation solvent is selected from at least one of water, ethanol, acetone, and acetonitrile. The precipitation solvent is an antisolvent that causes the biomimetic material to precipitate.

[0095] In some embodiments of the present invention, the mass ratio of the precipitating solvent to the triazine nitrogen-containing heterocyclic compound is 15–20:1. In some specific embodiments of the present invention, the mass ratio of the precipitating solvent to the triazine nitrogen-containing heterocyclic compound can be 15:1, 16:1, 17:1, 18:1, 19:1, or 20:1. In some embodiments of the present invention, the film-forming step employs isostatic pressing or dry film formation.

[0096] In some embodiments of the present invention, the pressure of the isostatic pressing film formation step is 30-50 MPa, for example, selected from 30 MPa, 31 MPa, 32 MPa, 33 MPa, 34 MPa, 35 MPa, 36 MPa, 37 MPa, 38 MPa, 39 MPa, 40 MPa, 41 MPa, 42 MPa, 43 MPa, 44 MPa, 45 MPa, 46 MPa, 47 MPa, 48 MPa, 49 MPa, and 50 MPa.

[0097] In some embodiments of the present invention, the holding time of the isostatic pressing film formation step is 1 to 10 min, for example, it can be selected from 1 min, 2 min, 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, 9 min, or 10 min.

[0098] In some embodiments of the present invention, the dry film-forming step is as follows: grinding and mixing solid electrolyte and binder, and then forming film by rolling or coating.

[0099] In some embodiments of the present invention, the mass ratio of solid electrolyte to binder is (4-49):1, for example, selected from 4:1, 6:1, 8:1, 10:1, 12:1, 14:1, 16:1, 18:1, 20:1, 22:1, 24:1, 26:1, 28:1, 30:1, 32:1, 34:1, 36:1, 38:1, 40:1, 42:1, 44:1, 46:1, 48:1, 49:1.

[0100] In some embodiments of the present invention, the adhesive is selected from at least one of polytetrafluoroethylene, polyvinylidene fluoride, and styrene-butadiene rubber.

[0101] In some embodiments of the present invention, step S2 is: mixing the electrolyte salt and the plasticizer to obtain a mixed solution; immersing the biomimetic material in the mixed solution to allow the electrolyte salt and plasticizer in the mixed solution to enter the biomimetic material, and then forming a film to obtain the solid electrolyte.

[0102] In some embodiments of the present invention, the concentration of the electrolyte salt in the mixed solution is 0.8 to 1.2 mol / L, and it can be selected, for example, from lithium chloride, lithium bromide, lithium bis(trifluoromethylsulfonyl)imide, or lithium bis(fluorosulfonyl)imide.

[0103] In some embodiments of the present invention, the number of soaking times is 1 to 5, for example, 1, 2, 3, 4, or 5 times.

[0104] In some embodiments of the present invention, the present invention also provides a solid-state battery, including a cathode, an anode, and the above-described solid electrolyte.

[0105] In some embodiments of the present invention, the room temperature lithium-ion conductivity of the above-mentioned solid-state battery is 0.1 to 17 mS / cm.

[0106] In some embodiments of the present invention, the ion transference number of the solid-state battery is 0.7 to 0.8.

[0107] Example 1

[0108] This example provides a solid electrolyte membrane, which is prepared by a method including the following steps:

[0109] (1) Weigh phloroglucinol and melamine (i.e., the precursor of the artificial biomimetic material) at a molar ratio of 1:1, and then dissolve them separately in dimethyl sulfoxide solution. The mass ratio of dimethyl sulfoxide to phloroglucinol is 18:1, and the mass ratio of dimethyl sulfoxide to melamine is 18:1. The dissolution temperature is 80℃. The two solutions are stirred and mixed for liquid-phase assembly for 0.5h. Then, a precipitation solvent is added, wherein the precipitation solvent is water, and the mass ratio of the precipitation solvent to melamine is 20:1. A suspension with precipitate is obtained. The solvent is removed by rotary evaporation or vacuum drying to obtain the artificial biomimetic material with specific channels.

[0110] (2) Dissolve lithium bis(fluorosulfonyl)imide in a mixed solution of acetonitrile and ethylene carbonate (plasticizer) at a volume ratio of 8:2 to obtain 10 mL of the mixed solution. The concentration of lithium bis(fluorosulfonyl)imide in the mixed solution is 1 mol / L.

[0111] (3) Soak 1g of the above-mentioned biomimetic material in the 10mL mixed solution in step (2) for 6h, take out the biomimetic structure, and soak it again in the newly prepared 10mL mixed solution in step (2) for 6h. Repeat the above soaking process 3 times so that the mixed solution completely enters the nano-flow channels of the biomimetic material.

[0112] (4) Take out the artificial biomimetic material that has been injected into the mixed solution and evaporate it at 80°C. After the solvent has completely evaporated, press it into a solid electrolyte membrane with a thickness of 290 μm using a pressure of 30 MPa. The actual object is shown in Figure 1.

[0113] The artificial biomimetic material was tested using transmission electron microscopy and high-resolution transmission electron microscopy, respectively, and the specific test images are shown in Figures 2 and 3. As shown in Figures 2 and 3, the artificial biomimetic material has a rod-like structure with a nanofluid channel size of 0.7 nm. During the pressing process of the rod-shaped artificial biomimetic material into a film under pressure, hydrogen bonds connect the different rod-shaped particles, forming an internally continuous nanofluid channel.

[0114] The lithium-ion conductivity of the solid electrolyte membrane in this example was tested at room temperature and 30 MPa pressure. The specific test results are shown in Figure 4. As can be seen from Figure 4, the room temperature ionic conductivity of the solid electrolyte membrane in this example is 17 mS / cm, and the measured lithium-ion mobility coefficient is 0.78.

[0115] The solid electrolyte membrane used in this example was assembled with a lithium manganese oxide cathode and a lithium anode to form a solid-state battery. Its charge-discharge performance and rate performance at room temperature and a current density of 0.3C were then tested. The specific test results are shown in Figures 5 and 6, respectively. As can be seen from Figures 5 and 6, the solid-state battery assembled with the solid electrolyte membrane used in this example has a voltage window up to 4.5V and a reversible capacity of 131mAh / g.

[0116] Example 2

[0117] The only difference between the solid electrolyte membrane preparation method provided in this example and that in Example 1 is that the 10 mL mixed solution in this example is composed of lithium bis(fluorosulfonyl)imide and N-methylpyrrolidone, and the concentration of lithium bis(fluorosulfonyl)imide is 1 mol / L.

[0118] The lithium-ion conductivity of the solid electrolyte membrane in this example was tested under a pressure of 30 MPa, and the room temperature ionic conductivity was measured to be 0.5 mS / cm.

[0119] Example 3

[0120] The only difference between the solid electrolyte membrane preparation method provided in this example and that in Example 1 is that the 10 mL mixed solution in this example is made of lithium chloride, water and acetonitrile, the concentration of lithium chloride is 1 mol / L, and the volume ratio of water to acetonitrile is 1:1.

[0121] The lithium-ion conductivity of the solid electrolyte membrane in this example was tested under a pressure of 30 MPa, and the room temperature ionic conductivity was measured to be 10 mS / cm.

[0122] Example 4

[0123] The only difference between the solid electrolyte membrane preparation method provided in this example and that in Example 1 is that the 10 mL mixed solution in this example is composed of lithium bis(trifluoromethanesulfonyl)imide and N-methylpyrrolidone, wherein the concentration of lithium bis(trifluoromethanesulfonyl)imide is 1 mol / L.

[0124] The lithium-ion conductivity of the solid electrolyte membrane in this example was tested under a pressure of 30 MPa, and the room temperature ionic conductivity was measured to be 0.8 mS / cm.

[0125] Example 5

[0126] The only difference between the solid electrolyte membrane preparation method provided in this example and that in Example 1 is that the 10 mL mixed solution in this example consists of lithium chloride, N,N-dimethylformamide and acetonitrile, the concentration of lithium chloride is 1 mol / L, and the volume ratio of N,N-dimethylformamide and acetonitrile is 2:1.

[0127] The lithium-ion conductivity of the solid electrolyte membrane in this example was tested under a pressure of 30 MPa, and the room temperature ionic conductivity was measured to be 3 mS / cm.

[0128] Example 6

[0129] The only difference between the solid electrolyte membrane preparation method provided in this example and Example 1 is that in this example, pyrogallol and melamine are replaced in equal amounts with tris(tris(benzene)sulfonic acid) and melamine in Example 1.

[0130] The lithium-ion conductivity of the solid electrolyte membrane in this example was tested under a pressure of 30 MPa, and the room temperature ionic conductivity was measured to be 0.1 mS / cm.

[0131] Example 7

[0132] The only difference between the solid electrolyte membrane preparation method provided in this example and Example 1 is that in this example, phloroglucinol and melamine are replaced in equal amounts with phloroglucinol and melamine in Example 1.

[0133] The lithium-ion conductivity of the solid electrolyte membrane in this example was tested under a pressure of 30 MPa, and the room temperature ionic conductivity was measured to be 5 mS / cm.

[0134] Example 8

[0135] The only difference between the solid electrolyte membrane preparation method provided in this example and Example 1 is that in this example, phloroglucinol and melamine in Example 1 are replaced in equal amounts with 2,4,6-tris(trifluoromethyl)-1,3,5-triazine.

[0136] The lithium-ion conductivity of the solid electrolyte membrane in this example was tested under a pressure of 30 MPa, and the room temperature ionic conductivity was measured to be 1 mS / cm.

[0137] Example 9

[0138] The only difference between the solid electrolyte membrane preparation method provided in this example and Example 1 is that in this example, phloroglucinol and 1,3,5-benzenetriformyl chloride are used to replace phloroglucinol and melamine in Example 1 in equal amounts.

[0139] The lithium-ion conductivity of the solid electrolyte membrane in this example was tested under a pressure of 30 MPa, and the room temperature ionic conductivity was measured to be 2 mS / cm.

[0140] The precursor of the artificial biomimetic material used in the preparation of the solid electrolyte membranes in Examples 1 to 9, the composition of the mixed solution, and the measured room temperature conductivity data of the solid electrolyte membranes are shown in Table 1 below.

[0141] Table 1. Precursor, mixed solution, and room temperature ionic conductivity data of artificial biomimetic materials

[0142] As shown in Table 1, this invention assembles an artificial biomimetic material from an organic precursor in a liquid phase. The biomimetic material is then immersed in a mixed solution composed of an electrolyte salt and a plasticizer, allowing the mixed solution to enter the nanofluid channels of the biomimetic material. After solvent evaporation, the solution is pressed to obtain a solid electrolyte. When this solid electrolyte is assembled into a solid-state battery, the battery exhibits a very high room-temperature ionic conductivity, reaching up to 17 mS / cm, significantly exceeding that of currently known solid electrolytes. Furthermore, this invention allows for adjustment of the room-temperature ionic conductivity of the prepared solid electrolyte membrane according to specific application requirements by adjusting the types and amounts of the organic precursor (i.e., small molecules), plasticizer, and electrolyte salt.

[0143] The embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A solid state electrolyte, characterized by: The solid electrolyte contains biomimetic materials, electrolyte salts, and plasticizers; the biomimetic materials are loaded with electrolyte salts and plasticizers; the biomimetic materials include monocyclic aromatic compounds and triazine nitrogen-containing heterocyclic compounds; the monocyclic aromatic compounds and the triazine nitrogen-containing heterocyclic compounds are linked by hydrogen bonds; the biomimetic materials have nanopores with a diameter of 0.3 to 1 nm.

2. The solid-state electrolyte of claim 1, wherein: The monocyclic aromatic compound contains a functional group selected from at least one of oxygen-containing functional groups, nitrogen-containing functional groups, sulfur-containing functional groups, and halogens; And / or, the triazine nitrogen-containing heterocyclic compound contains a functional group selected from at least one of oxygen-containing functional groups, nitrogen-containing functional groups, sulfur-containing functional groups, and halogens.

3. The solid-state electrolyte of claim 2, wherein: The oxygen-containing functional group includes at least one of carboxyl, hydroxyl, and carbonyl groups; And / or, the sulfur-containing functional group includes at least one of sulfonic acid group, mercapto group, and sulfinyl group; And / or, the nitrogen-containing functional group includes at least one of nitro, amino, and amide groups.

4. The solid electrolyte according to claim 1, characterized in that: The monocyclic aromatic compound is selected from at least one of pyromellitic acid, pyromellitic acid, phloroglucinol, and terephthalamide.

5. The solid electrolyte according to claim 1, characterized in that: The triazine-type nitrogen-containing heterocyclic compound is selected from at least one of melamine, 2,4,6-tris(trifluoromethyl)-1,3,5-triazine, 1,3,5-triacryloylhexahydro-1,3,5-triazine, and cyanuric chloride.

6. The solid electrolyte according to claim 1, characterized in that: The electrolyte salt is selected from at least one of lithium chloride, lithium bromide, lithium bis(trifluoromethylsulfonyl)imide, and lithium bis(fluorosulfonyl)imide; Alternatively, the electrolyte salt is selected from at least one of sodium chloride, sodium bromide, sodium bis(trifluoromethylsulfonyl)imide, and sodium bis(fluorosulfonyl)imide; Alternatively, the electrolyte salt is selected from at least one of potassium chloride, potassium bromide, potassium bis(trifluoromethylsulfonyl)imide, and potassium bis(fluorosulfonyl)imide.

7. The solid electrolyte according to claim 1, characterized in that: The plasticizer comprises at least one of acetonitrile, fluoroacetonitrile, succinic anion, water, ethylene carbonate, N-methylpyrrolidone, N,N-dimethylformamide, methyl carbonate, ethylene carbonate, propylene carbonate, diethyl carbonate, dimethyl ether, diethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxane, tetrahydrofuran, toluene, ethanol, ethyl acetate, propyl acetate, fluoroethylene carbonate, methyltrifluoroethyl carbonate, hydrofluoroether, imidazole ionic liquids, pyridine ionic liquids, and quaternary ammonium ionic liquids.

8. The solid electrolyte according to claim 1, characterized in that: The plasticizer comprises plasticizing component A and plasticizing component B in a volume ratio of (1-9):1; plasticizing component A is selected from at least one of acetonitrile, fluoroacetonitrile, succinic anionyl nitrile, water, N-methylpyrrolidone, and N,N-dimethylformamide; plasticizing component B is selected from at least one of ethylene carbonate, acetonitrile, methyl carbonate, ethylene carbonate, propylene carbonate, diethyl carbonate, dimethyl ether, diethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxane, tetrahydrofuran, toluene, ethanol, ethyl acetate, propyl acetate, fluoroethylene carbonate, methyltrifluoroethyl carbonate, hydrofluoroether, imidazole ionic liquids, pyridine ionic liquids, and quaternary ammonium ionic liquids, and plasticizing component A and plasticizing component B are not the same.

9. The solid electrolyte according to claim 8, characterized in that: The plasticizer comprises acetonitrile and ethylene carbonate in a volume ratio of (1-9):1; Alternatively, the plasticizer comprises water and acetonitrile in a volume ratio of (1-9):1; Alternatively, the plasticizer may comprise N,N-dimethylformamide and acetonitrile in a volume ratio of (1-9):

1.

10. The method for preparing the solid electrolyte according to any one of claims 1 to 9, characterized in that: Includes the following steps: S1: Biomimetic materials are obtained by assembling monocyclic aromatic compounds and triazine nitrogen-containing heterocyclic compounds in a solvent; S2: Load the biomimetic material with electrolyte salt and plasticizer, and then form a film to obtain the solid electrolyte.

11. The method for preparing a solid electrolyte according to claim 10, characterized in that: The film-forming step employs isostatic pressing or dry film-forming.

12. The method for preparing a solid electrolyte according to claim 11, characterized in that: The pressure for the isostatic pressing film formation step is 30-50 MPa; And / or, the holding time for the isostatic pressing film formation step is 1 to 10 minutes.

13. The method for preparing a solid electrolyte according to claim 10, characterized in that: The dry film-forming step is as follows: the solid electrolyte and binder are ground and mixed, and then a film is formed by rolling or coating.

14. The method for preparing a solid electrolyte according to claim 10, characterized in that: Step S2 is as follows: the electrolyte salt and the plasticizer are mixed to obtain a mixed solution; the concentration of the electrolyte salt in the mixed solution is 0.8-1.2 mol / L; the biomimetic material is immersed in the mixed solution to allow the electrolyte salt and plasticizer in the mixed solution to enter the biomimetic material, and then a film is formed to obtain the solid electrolyte.

15. A solid-state battery, characterized in that: Includes the solid electrolyte as described in any one of claims 1 to 9.

16. The application of the solid electrolyte according to any one of claims 1 to 9 and / or the solid battery according to claim 15 in electronic products.

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