An organic-inorganic composite solid electrolyte and its preparation and application

Abstract

The present invention relates to an organic-inorganic composite solid electrolyte and a preparation method thereof. By in-situ polymerization reaction on the surface of an oxide solid electrolyte to generate a polymer containing C=N and C-N groups, an organic-inorganic composite solid electrolyte with higher room temperature ionic conductivity and wider electrochemical window is prepared. The composite solid electrolyte prepared by the present invention has a room temperature ionic conductivity of more than 0.1mS / cm, an electrochemical window greater than 4.5V, and an alkali metal cation migration number greater than 0.9. In addition, the composite solid electrolyte is easy to form a film, and the thickness of the prepared composite solid electrolyte film is thin. A solid-state alkali metal battery is assembled with this electrolyte membrane, which has good interface stability with the positive and negative electrodes, and can inhibit the growth of alkali metal dendrites, significantly improving battery performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of solid-state batteries, and in particular relates to an organic-inorganic composite solid electrolyte and its preparation and application. Background Art

[0002] Lithium-ion batteries have expanded from the portable device and consumer electronics market to electric vehicles and large-scale energy storage, but the safety hazards of batteries such as combustion and explosion limit their further development. At present, the preparation of alkali metal solid-state batteries with solid electrolytes has attracted much attention due to their high energy density and safety. At present, solid electrolyte materials are divided into two categories: (1) polymer-based solid electrolytes; (2) inorganic solid electrolytes. Inorganic solid electrolytes mainly include sulfide inorganic solid electrolytes and oxide inorganic solid electrolytes. Sulfide inorganic solid electrolytes have high room temperature ionic conductivity (up to 10 -2 S cm -1 ) and low synthesis temperature, but the chemical stability of sulfide solid electrolytes is poor. Chemical reactions will occur rapidly after contact with air and water, which seriously affects the prospects for large-scale application of sulfide electrolytes. Although the room temperature ionic conductivity of oxide inorganic solid electrolytes is relatively high, the material is brittle, has poor processability, is difficult to form into a film, and has a large interface impedance with the positive and negative electrodes. High-temperature sintering can obtain a dense inorganic solid electrolyte membrane, but it will cause element mutual diffusion and even side reactions between the solid electrolyte and the positive electrode material, increasing the interface impedance. In addition, high-temperature sintering consumes a lot of energy and the process is complicated, which is not conducive to the practical application of solid-state batteries. The room temperature ionic conductivity of polymer-based solid electrolytes is slightly lower than that of inorganic solid electrolytes, but they have good flexibility, low interface impedance with the positive and negative electrodes, and are easy to prepare large-area thin films.

[0003] For example, CN201811135432.8 discloses an organic-inorganic composite electrolyte, its preparation method, and its application in solid lithium-ion secondary batteries. The composite electrolyte is composed of a medium-temperature viscoelastic transition polymer, a lithium salt, and a fast ion conductor ceramic powder. The organic-inorganic composite electrolyte membrane prepared by the invention has both organic and inorganic phases with ion conductivity, which improves room temperature conductivity. In addition, the prepared organic-inorganic composite electrolyte membrane is non-sticky at room temperature, easy to roll up and multi-layer composite with pole pieces, suitable for industrial production. CN201910451384.1 discloses a three-dimensional bicontinuous conductive phase organic-inorganic composite electrolyte and an all-solid-state lithium battery composed thereof, as well as its preparation and application. The inorganic phase is a sulfide fast ion conductor with a three-dimensional porous skeleton, and the organic phase includes a lithium salt and a polymer. The organic phase is filled in the sulfide fast ion conductor with a three-dimensional porous skeleton or is both filled in the sulfide fast ion conductor with a three-dimensional porous skeleton and coated on the surface of the sulfide fast ion conductor with a three-dimensional porous skeleton. The room temperature ionic conductivity can reach 2×10 -4 ~1×10-3 Scm -1 The polymer coating on the surface of the sulfide electrolyte makes the composite electrolyte have excellent stability to metallic lithium, and the electrochemical window of the composite electrolyte is higher than 4.6V vs.Li + / Li. The assembled all-solid-state lithium battery has excellent cycle stability. CN111952672A discloses a preparation method and application of a high-performance solid electrolyte composite membrane, which first uses a compound containing functional groups such as phenolic hydroxyl or amino groups to polymerize and coat an inorganic solid electrolyte powder, then mixes the coated inorganic solid electrolyte powder with a polymer electrolyte and coats it to obtain a solid electrolyte composite membrane, and uses this electrolyte membrane to assemble a solid-state lithium metal battery; in the above patent, an inorganic solid electrolyte and a polymer electrolyte are used to prepare a composite solid electrolyte, which has good ionic conductivity and optimizes the film-forming property and interface stability of the solid electrolyte. However, the dual ion conduction characteristics of the polymer electrolyte containing alkali metal cation salts will lead to concentration polarization of alkali metal cations inside the solid electrolyte, and ultimately produce alkali metal dendrites. The method of polymerizing and coating inorganic solid electrolyte powder with compounds containing functional groups such as phenolic hydroxyl or amino groups only discusses the optimization of the dispersibility of inorganic electrolyte nanoparticles, and does not explore the solid electrolyte grain boundary impedance, electrode / solid electrolyte interface problems, etc. Therefore, developing new solid electrolytes, eliminating the high grain boundary resistance of oxide solid electrolytes, and achieving interface stability of electrodes / solid electrolytes are of great significance for building high-performance solid-state batteries. Summary of the Invention

[0004] The purpose of the present invention is to develop an organic-inorganic composite solid electrolyte and its preparation and application, to achieve high ionic conductivity, wide electrochemical window, small interface impedance with electrodes, and effective inhibition of alkali metal dendrite growth of the composite electrolyte, and to promote the industrialization of solid-state batteries.

[0005] The organic-inorganic composite solid electrolyte of the present invention is composed of an inorganic oxide solid electrolyte that can conduct alkali metal cations and a polymer containing C=N and / or CN groups formed by in-situ polymerization on its surface; the mass ratio of the inorganic oxide solid electrolyte to the polymer is 1:0.1-10, preferably 1:0.5-5;

[0006] The oxide inorganic solid electrolyte includes A x MO y , one or more of garnet-type inorganic solid electrolytes, perovskite-type inorganic solid electrolytes and antiperovskite-type inorganic solid electrolytes;

[0007] The A x MO yType inorganic solid electrolyte, wherein 0.6≤x≤5, 1<y≤4, A is one or more of Li, Na or K, and M is one or more of Si, B, Ge, Zr, Al, Ga, Ti, P, S, As, Se, Nb, Sn, Sb, Te, Nd, Y, I, and La;

[0008] The garnet-type inorganic solid electrolyte comprises A 7-m La3Zr 2-m M m O 12 、A 7-2n La3Zr 2-n N n O 12 and A 7- 3d D d La3Zr2O 12 , wherein 0≤m≤2, 0≤n≤2, 0≤d≤7 / 3, A is one or more of Li, Na or K, M is one or more of Ta and Nb, N is one or more of W and Mo, and D is one or more of Ga and Al;

[0009] The perovskite inorganic solid electrolyte is A 3x La 0.67-x TiO3, wherein 0.04<x<0.17, and A is one or more of Li, Na, or K;

[0010] The antiperovskite inorganic solid electrolyte is A3OX, wherein A is one or more of Li, Na or K, and X is one or more of Cl, Br or I;

[0011] The particle size of the oxide solid electrolyte is 1nm~100μm; the room temperature ionic conductivity is not less than 10 -4 mS / cm; the ratio of the number of charges transported by alkali metal cations in oxide solid electrolytes to the total number of charges transported by anions and cations is 1;

[0012] The general structural formula of the polymer containing C=N and CN groups is:

[0013]

[0014] Where R1-R 12 Each of them is independently one or more of a C2-C8 alkyl group, a C1-C8 alkylene group, a 3-7 membered cycloalkyl group, an aryl group or a C3-C6 acrylate group, wherein 5≤n≤500, 5≤x+y+z≤500, and n, x, y and z are all integers greater than or equal to zero.

[0015] The method for preparing the organic-inorganic composite solid electrolyte is characterized by mixing a polymer precursor with an inorganic oxide solid electrolyte powder material, wherein oxygen atoms on the surface of the inorganic oxide solid electrolyte, which are Lewis bases, catalyze a polymerization reaction of the polymer precursor, thereby in situ generating a polymer containing C═N and / or CN groups on the surface of the inorganic oxide solid electrolyte. The specific preparation process includes the following steps:

[0016] (1) fully mixing an oxide solid electrolyte powder material and a polymer precursor in an organic solvent to prepare a suspension; the mass ratio of the oxide solid electrolyte to the polymer precursor is 1:0.1 to 10; the mass ratio of the organic solvent to the polymer precursor is 5 to 50:1;

[0017] (2) stirring the mixture suspension obtained in step (1) at a speed of 100 to 3000 r / min and a temperature of 45° C. to 300° C. for 1 to 72 h, wherein the speed is preferably 1200 to 1600 r / min, the temperature is preferably 85 to 95° C., and the time is preferably 8 to 16 h;

[0018] (3) drying the mixture containing the organic-inorganic composite solid electrolyte obtained in step (2) at a temperature of 40 to 300° C. for a drying time of not less than 24 hours to obtain an organic-inorganic composite solid electrolyte powder material.

[0019] The polymer precursor in step (1) is an organic compound having a nitrogen-containing unsaturated bond, including one or more of propionitrile, butyronitrile, valeronitrile, capronitrile, heptanenitrile, octanonitrile, nonanenitrile, sunflower nitrile, malononitrile, succinonitrile, glutaronitrile, adiponitrile, pimelonitrile, suberonitrile, azelaic acid dinitrile, sunflower nitrile, cyclopropylnitrile, cyclobutylnitrile, cyclopentylnitrile, cyclohexylnitrile, cycloheptylnitrile, tetracyanoethylene, acrylonitrile, isobutyronitrile, phthalonitrile, benzonitrile, benzyl cyanide, propionitrile, methyl 2-cyanoacrylate, ethyl 2-cyanoacrylate, propyl 2-cyanoacrylate, butyl 2-cyanoacrylate, etc.;

[0020] The organic solvent includes one or more of diphenyl ether, dimethyl sulfoxide, N,N-dimethylformamide, dimethylacetamide, N-methylpyrrolidone, hexamethylphosphorotriamide, and hexaethylphosphorotriamide.

[0021] The solid electrolyte membrane of the organic-inorganic composite solid electrolyte is characterized in that the ratio of the number of charges transported by alkali metal cations in the composite solid electrolyte to the total number of charges transported by anions and cations is not less than 0.9.

[0022] The method for preparing a solid electrolyte membrane of an organic-inorganic composite solid electrolyte is characterized in that: the organic-inorganic composite solid electrolyte membrane is prepared by a dry film forming method or a wet film forming method;

[0023] The dry film forming method is to use a film press to press the prepared organic-inorganic composite solid electrolyte powder material at 45-300°C and 101.3kPa-20MPa to form an organic-inorganic composite solid electrolyte membrane; the thickness of the organic-inorganic composite solid electrolyte membrane is 1-500μm, and the porosity is less than or equal to 20%;

[0024] The wet membrane preparation method comprises adding the prepared organic-inorganic composite solid electrolyte powder material to a solvent, stirring at a speed of 100 to 3000 r / min and a temperature of 45°C to 300°C for 1 to 72 hours to prepare a slurry; applying the prepared slurry to a flat plate or film-shaped skeleton material by casting, casting, spin coating or coating, and drying the solvent at a temperature of 40 to 300°C to form a diaphragm, with the drying treatment time being 1 to 72 hours; the thickness of the organic-inorganic composite solid electrolyte membrane is 1 to 500 μm;

[0025] The flat plate may be a glass plate, a polytetrafluoroethylene plate or a stainless steel plate;

[0026] The membranous skeleton material may be a dense membrane or a porous membrane. The dense membrane may be a composite membrane composed of one or more of Nafion membrane, perfluorosulfonic acid-polytetrafluoroethylene membrane, polytrifluorostyrene sulfonic acid membrane, polydifluorostyrene sulfonic acid membrane, polyaryletherketone sulfonic acid membrane, polyimide sulfonic acid membrane, and sulfonated polysulfone membrane; the porous membrane may be a composite membrane composed of one or more of PP membrane, PE membrane, cellulose non-woven membrane, polyimide non-woven membrane, algae fiber non-woven membrane, aramid non-woven membrane, polyarylsulfoneamide non-woven membrane, polypropylene non-woven membrane, glass fiber membrane, and polyethylene terephthalate non-woven membrane.

[0027] The solvent includes one or more of acetonitrile, cyclohexane, tetrahydrofuran, diphenyl ether, dimethyl sulfoxide, N,N-dimethylformamide, dimethylacetamide, N-methylpyrrolidone, hexamethylphosphorotriamide, and hexaethylphosphorotriamide.

[0028] The organic-inorganic composite solid electrolyte membrane is used to assemble a solid-state battery, which is composed of a positive electrode, an organic-inorganic composite solid electrolyte membrane and a negative electrode;

[0029] The positive electrode is composed of a positive electrode active material or a positive electrode active material with a polymer surface layer, a conductive agent and a binder;

[0030] The positive electrode active material is lithium ferrous phosphate, lithium manganese iron phosphate, lithium cobalt oxide, lithium manganese oxide, nickel cobalt manganese ternary material, lithium nickel manganese oxide, transition metal oxide A x MO2, wherein 1≤x≤2, A is one or two of Na or K, M is one or more of Co, Fe, Mn and Ni, etc., polyanion compound A X M Y(X a O b )Z w , wherein 1≤X≤6, 1≤Y≤5, 1≤a≤8, 4≤b≤32, 0≤w≤3, A is one or more of Na or K, M is one or more of Ti, V, Cr, Mn, Fe, Co, Ni, Ca, Mg, Al, Nb, etc., X is one or more of Si, S, P, As, B, Mo, W, Ge, etc., Z is one or more of F, O, H, etc., Prussian blue compound A x M1[M2(CN)6] 1-y , wherein 0<x<2, 0<y<1, A is Na or K, M1 and M2 are one or more of Mn, Fe, Co, Ni, Cu, Zn, etc.; the polymer surface layer on the surface of the positive electrode active material is a polymer containing C=N and / or CN groups formed by in situ polymerization of an organic compound having a nitrogen-containing unsaturated bond;

[0031] The method for preparing the polymer surface layer on the surface of the positive electrode active material comprises: adding a polymer precursor and a positive electrode active material into an organic solvent, stirring to prepare a mixture, catalyzing the Lewis base oxygen atom in the positive electrode active material to cause a polymerization reaction of the precursor to in situ generate a polymer containing C=N and / or CN groups, and drying the solvent to obtain a positive electrode material powder with a surface layer; the specific preparation method includes:

[0032] The positive electrode active material includes lithium cobalt oxide, lithium manganese oxide, nickel cobalt manganese ternary material, lithium nickel manganese oxide and transition metal oxide A x MO2, wherein 1≤x≤2, A is one or two of Na or K, and M is one or more of Co, Fe, Mn, and Ni, etc., and the mixture is stirred at a speed of 100 to 3000 r / min and a temperature of 45°C to 300°C for 1 to 72 hours, wherein the speed is preferably 1200 to 1600 r / min, the temperature is preferably 85 to 95°C, and the time is preferably 10 to 14 hours, and the precursor can undergo polymerization to form a polymer containing C=N and / or CN groups;

[0033] The polymer precursor is an organic compound having a nitrogen-containing unsaturated bond, including one or more of propionitrile, butyronitrile, valeronitrile, capronitrile, heptanenitrile, octanonitrile, nonanenitrile, sunflower nitrile, malononitrile, succinonitrile, glutaronitrile, adiponitrile, pimelonitrile, suberonitrile, azelaic acid dinitrile, sunflower nitrile, cyclopropylnitrile, cyclobutylnitrile, cyclopentylnitrile, cyclohexylnitrile, cycloheptylnitrile, tetracyanoethylene, acrylonitrile, isobutyronitrile, phthalonitrile, benzonitrile, benzyl cyanoacrylate, propionitrile, methyl 2-cyanoacrylate, ethyl 2-cyanoacrylate, propyl 2-cyanoacrylate, butyl 2-cyanoacrylate, etc.;

[0034] The organic solvent includes one or more of diphenyl ether, dimethyl sulfoxide, N,N-dimethylformamide, dimethylacetamide, N-methylpyrrolidone, hexamethylphosphoramide, and hexaethylphosphoramide; the mass ratio of the oxide solid electrolyte to the polymer precursor is 1:0.1-10; the mass ratio of the organic solvent to the polymer precursor is 5-50:1; the conductive agent is one or more of acetylene black, BLACK PEARLS 2000, Ketjen black, Super-P, carbon nanotubes, carbon nanofibers, activated carbon, and graphene;

[0035] The binder is a compound composed of one or more of styrene-butadiene rubber, polytetrafluoroethylene, sodium carboxymethyl cellulose, polyolefin, polyvinylidene fluoride and its derivatives, and organic-inorganic composite electrolyte;

[0036] The positive electrode sheet is prepared by mixing a positive electrode active material with a surface layer attached thereto and / or without a surface layer, a conductive agent, a binder, and a solvent by stirring, grinding, and / or ball milling to form a slurry, coating the slurry on the surface of a current collector by casting, casting, spin coating, or coating, and drying to obtain a positive electrode sheet; the solvent used includes one or more of deionized water, ethanol, acetone, acetonitrile, cyclohexane, tetrahydrofuran, diphenyl ether, dimethyl sulfoxide, N,N-dimethylformamide, dimethylacetamide, N-methylpyrrolidone, hexamethylphosphoramide, and hexaethylphosphoramide;

[0037] The current collector is one of aluminum foil, carbon-coated aluminum foil, nickel foam, and titanium foil;

[0038] The solid-state battery has a solid electrolyte intermediate layer or no intermediate layer between the positive electrode and the organic-inorganic composite solid electrolyte membrane;

[0039] The solid electrolyte intermediate layer between the positive electrode and the organic-inorganic composite solid electrolyte membrane can be an inorganic solid electrolyte, a polymer solid electrolyte, an inorganic solid electrolyte-polymer solid electrolyte composite solid electrolyte, an inorganic solid electrolyte-polymer composite solid electrolyte or a lithium salt-polymer composite solid electrolyte;

[0040] The inorganic solid electrolyte includes one or more of an oxide inorganic solid electrolyte, a sulfide inorganic solid electrolyte, a halide inorganic solid electrolyte, and a boride inorganic solid electrolyte;

[0041] The oxide inorganic solid electrolyte includes A x MO y , one or more of garnet-type inorganic solid electrolytes, perovskite-type inorganic solid electrolytes and antiperovskite-type inorganic solid electrolytes;

[0042] The A x MO y Type inorganic solid electrolyte, 0.6≤x≤5, 1<y≤4, A is one or more of Li, Na or K, and M is one or more of Si, B, Ge, Zr, Al, Ga, Ti, P, S, As, Se, Nb, Sn, Sb, Te, Nd, Y, I, and La;

[0043] The garnet-type inorganic solid electrolyte comprises A 7-m La3Zr 2-m M m O 12 、A 7-2n La3Zr 2-n N n O 12 and A 7- 3d D d La3Zr2O 12 , wherein 0≤m≤2, 0≤n≤2, 0≤d≤7 / 3, A is one or more of Li, Na or K, M is one or more of Ta and Nb, N is one or more of W and Mo, and D is one or more of Ga and Al;

[0044] The perovskite inorganic solid electrolyte is A 3x La 0.67-x TiO3, wherein 0.04<x<0.17, and A is one or more of Li, Na, or K;

[0045] The antiperovskite inorganic solid electrolyte is A3OX, wherein A is one or more of Li, Na or K, and X is one or more of Cl, Br or I;

[0046] The sulfide inorganic solid electrolyte includes β-A3PS4, A7P3S 11 、thio-LISICON-type A 10± 1MP2X 12 , Argyrodite-type A6PS5X', wherein A is one or more of Li, Na or K, M is one or more of Ge, Si, Sn, Al or P, X is one or more of S or Se, and X' is one or more of Cl, Br or I;

[0047] The halide inorganic solid electrolyte is A3YX6, wherein A is one or more of Li, Na or K, and X is one or more of Cl, Br or I;

[0048] The boride inorganic solid electrolyte includes ABH4, ABH4-AX, ACB 11 H 12 , AM(BH4)3Cl and A2B 12 H 12 , wherein A is one or more of Li, Na or K, X is one or more of Cl, Br or I, and M is one or more of La, Ce or Gd;

[0049] The polymer includes one or more of polyolefin, polyvinylidene fluoride, poly(vinylidene fluoride-hexafluoropropylene), cellulose, epoxy resin, polyacrylonitrile, polymethyl ethylene carbonate, polyethylene carbonate, polyimide, polyphenylene olefin, polysulfone, polyaryletherketone, polyarylethersulfone, polybenzimidazole, and polybenzothiazole;

[0050] Alkali metal salts include one or more of ATFSI, AFSI, ABOB, APF6, AClO4, AAsF6, ABF4, ACH3SO3, ACF3SO3, AC4BO8, AC2BF2O4 (A is Li, Na or K);

[0051] The negative electrode is one of an alkali metal negative electrode and an alkali metal composite negative electrode;

[0052] The alkali metal is Li, Na or K;

[0053] The composite negative electrode is composed of an alkali metal and a conductive skeleton material;

[0054] The conductive skeleton material is divided into three-dimensional self-supporting materials and composite skeleton materials made of one of carbon-based materials or silicon-based materials, a conductive agent and a binder.

[0055] The three-dimensional self-supporting material includes one or more of stainless steel mesh, copper mesh, nickel mesh, foam nickel, foam copper, carbon cloth, carbon fiber felt, carbon plate, graphene, and electrostatically spun organic polymer fiber cloth;

[0056] The carbon-based material is one or more of graphite, amorphous carbon, mesocarbon microbeads, hard carbon, and soft carbon;

[0057] The silicon-based material is one or more of silicon, tin-silicon alloy, aluminum-silicon alloy, titanium-silicon alloy, nickel-silicon alloy, tungsten-silicon alloy, iron-silicon alloy, copper-silicon alloy, manganese-silicon alloy, cobalt-silicon alloy, germanium-silicon alloy, zinc-silicon alloy, magnesium-silicon alloy, and gallium-silicon alloy;

[0058] The binder is a compound composed of one or more of styrene-butadiene rubber, polytetrafluoroethylene, sodium carboxymethyl cellulose, polyolefin, polyvinylidene fluoride and its derivatives, and organic-inorganic composite electrolyte;

[0059] The preparation method of the composite skeleton material is as follows: a carbon-based material or a silicon-based material, a conductive agent, a binder and a solvent are mixed by stirring, grinding or ball milling to form a slurry, the slurry is coated on the surface of a copper foil or titanium foil current collector by casting, casting, spin coating or coating, and dried to obtain a negative electrode plate; the solvent used includes one or more of deionized water, ethanol, acetone, acetonitrile, cyclohexane, tetrahydrofuran, diphenyl ether, dimethyl sulfoxide, N,N-dimethylformamide, dimethylacetamide, N-methylpyrrolidone, hexamethylphosphoramide, and hexaethylphosphoramide;

[0060] The composite negative electrode is prepared by introducing alkali metal into the conductive skeleton by electrochemical deposition of alkali metal, melt infiltration of alkali metal or pressure filling of alkali metal;

[0061] The solid-state battery has a solid electrolyte interlayer or no interlayer between the alkali metal negative electrode or composite negative electrode and the organic-inorganic composite solid electrolyte membrane; the solid electrolyte interlayer can be an inorganic solid electrolyte, a polymer solid electrolyte, an inorganic solid electrolyte-polymer solid electrolyte composite solid electrolyte, an inorganic solid electrolyte-polymer composite solid electrolyte, or a lithium salt-polymer composite solid electrolyte;

[0062] The solid-state battery is assembled into a solid-state battery by stacking or winding the negative electrode, the organic-inorganic composite solid electrolyte membrane and the positive electrode. The battery can be a button battery, a square soft-pack battery, a square shell battery or a cylindrical battery.

[0063] The composite solid electrolyte produced by the present invention has a room-temperature ionic conductivity exceeding 0.1 mS / cm, an electrochemical window greater than 4.5 V, and an alkali metal cation transference number greater than 0.9. Furthermore, the composite solid electrolyte is easy to form into a thin film. When assembled into a solid-state alkali metal battery using this electrolyte membrane, it exhibits excellent interfacial stability with the positive and negative electrodes, inhibits the growth of alkali metal dendrites, and significantly improves battery performance.

[0064] The advantages of the present invention are:

[0065] 1. The surface oxygen atoms of the inorganic oxide solid electrolyte that can conduct alkali metal cations used in the present invention are Lewis bases, which can catalyze the reaction of organic compounds with nitrogen-containing unsaturated bonds, promote the partial breaking of nitrogen-containing unsaturated bonds, and cause these organic compounds to undergo polymerization reactions on the surface of the oxide solid electrolyte to form polymers containing C=N and CN groups. The C=N and CN polar groups have a high electron cloud density, which attracts the alkali metal cations of the inorganic oxide solid electrolyte to enrich on the surface, forming a space charge layer that is more conducive to the transmission of alkali metal cations at the interface between the organic phase and the inorganic solid electrolyte, becoming the main conduction path for alkali metal cations in the organic-inorganic composite electrolyte, and significantly improving the room temperature ionic conductivity of the organic-inorganic composite electrolyte. In addition, the reaction of organic compounds with nitrogen-containing unsaturated bonds with the Lewis base oxygen atoms on the surface of the positive electrode can form a surface layer on the surface of the positive electrode material, thereby improving battery performance.

[0066] 2. The present invention adopts an inorganic oxide solid electrolyte with single ion conduction characteristics to be combined with an organic phase to prepare an organic-inorganic composite solid electrolyte. Since no alkali metal cation salt is added, the composite solid electrolyte is a single ion conductor and has the advantage of a high ion migration number, which can inhibit the growth of alkali metal dendrites. Since it contains an inorganic oxide solid electrolyte, the electrochemical window of the composite solid electrolyte is significantly improved compared with the polymer electrolyte, and it has a good application prospect.

[0067] 3. The organic-inorganic composite solid electrolyte prepared by the present invention uniformly disperses the oxide solid electrolyte in the composite solid electrolyte slurry. The polymer phase is flexible, which improves the processing performance of the composite solid electrolyte. The prepared composite solid electrolyte is easy to prepare a large-area thin film, effectively reducing the impedance of the membrane. At the same time, because the prepared organic-inorganic composite solid electrolyte has flexibility, it forms a good interface contact with the positive and negative electrodes, avoiding the problems of the oxide solid electrolyte itself decomposing due to high-temperature calcination, resulting in a decrease in ionic conductivity, the mutual diffusion of elements between the solid electrolyte and the electrode material, and even side reactions leading to an increase in interface impedance. These advantages enable the organic-inorganic composite solid electrolyte membrane to have rapid alkali metal ion conduction performance, good interface stability with the positive and negative electrodes, the ability to inhibit dendrite growth, and oxidation resistance stability, which can significantly improve the safety performance and cycle life of the battery.

[0068] 4. The present invention adopts this single-ion conductor composite solid electrolyte to prepare solid-state batteries. The preparation method is compatible with the equipment and processes of existing lithium-ion batteries. It can be assembled in a variety of ways, including stacking and winding, to achieve the preparation of almost all types of batteries, including button batteries, soft-pack batteries, square-shell batteries, and cylindrical batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Figure 1This is a TEM image of LAGP after composited with succinonitrile in Comparative Example 1. As can be seen from the figure, no amorphous layered structure can be observed on the surface of LAGP after composited with succinonitrile. This is because the oxygen atoms of the LAGP oxide solid electrolyte are present in the phosphate groups, which cannot promote the in situ polymerization of succinonitrile on the LAGP surface.

[0070] Figure 2 This is a TEM image of LLZTO after being composited with ethylene glycol in Comparative Example 2. As can be seen from the figure, no amorphous layered structure can be observed on the surface of LLZTO after composited with ethylene glycol. This indicates that since ethylene glycol does not contain nitrogen-containing unsaturated bonds, it cannot react with oxygen atoms on the surface of the oxide solid electrolyte LLZTO, and no polymer surface layer is formed on the LLZTO surface.

[0071] Figure 3 This is a cycle-specific capacity curve of the LFP battery assembled with the composite solid electrolyte membrane in Comparative Example 2. The figure shows that the battery assembled with the composite electrolyte membrane prepared by combining LLZTO and ethylene glycol has a low specific capacity and poor cycle stability. After 53 cycles at a rate of 1C, the capacity retention rate is less than 80%.

[0072] Figure 4 and Figure 5 TEM images of the inorganic oxide solid electrolyte LLZTO before and after the reaction with the polymer precursor succinonitrile in Example 1. Figure 1 and 2 It can be seen that the surface of the LLZTO particles after the reaction with succinonitrile has a uniform amorphous surface layer. This indicates that succinonitrile, under the catalytic effect of LLZTO, forms a surface layer on the surface of LLZTO, changing the surface structure of LLZTO. Figure 6 This is a comparison of the XRD patterns of the oxide solid electrolyte LLZO powder before and after compounding with methyl cyanoacrylate in Example 3. Because the LLZO sample after compounding with methyl cyanoacrylate was sealed with polyimide tape to prevent damage from water and oxygen, a carbon peak can be observed in the figure. Otherwise, the peak shape of the LLZO powder after compounding is identical to that of the powder before compounding with methyl cyanoacrylate, indicating that the LLZO crystal form has not changed.

[0073] Figure 7 This is a comparison of the impedance of the LLZO solid electrolyte membrane before and after compounding with methyl cyanoacrylate in Example 3. It can be seen from the figure that the apparent impedance of the solid electrolyte membrane after compounding with methyl cyanoacrylate is significantly reduced, and the ion conductivity is significantly improved.

[0074] Figure 8The following is a comparison of the cycle-specific capacity of the battery assembled with the solid electrolyte membrane before and after compounding with isobutyronitrile in Example 2. The figure shows that the specific capacity and cycle stability of the battery assembled with the composite electrolyte membrane prepared by compounding with isobutyronitrile are improved, with a capacity retention rate of 84.94% after 300 cycles at a 1C rate. DETAILED DESCRIPTION

[0075] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0076] Comparative Example 1:

[0077] In this comparative example, 0.6g of succinonitrile and 1.2g of lithium aluminum germanium phosphate (LAGP) powder were added to 10g of N,N-dimethylformamide, and stirred at a speed of 1500r / min for 4h at room temperature to obtain a suspension. The obtained suspension was stirred at a speed of 500r / min for 12h at 90°C to obtain an organic-inorganic composite solid electrolyte slurry. The slurry was placed in a vacuum oven at 100°C and vacuum dried for 24h to obtain a succinonitrile-LAGP composite solid electrolyte powder material. The succinonitrile-LAGP composite solid electrolyte was characterized by TEM, as shown in FIG. Figure 1 As shown, no amorphous layered structure can be observed on the surface of LAGP, which indicates that succinonitrile does not undergo polymerization reaction on the surface of LAGP to form a surface layer. 1g of organic-inorganic composite solid electrolyte powder was evenly dispersed in 5g of DMF solvent and stirred at a speed of 1500r / min at 45°C for 12h to obtain a uniform slurry. The slurry was coated on a cellulose membrane by a coating method and then vacuum dried at 100°C for 24h. After complete drying, an organic-inorganic composite solid electrolyte membrane was obtained, which was cut into discs with a diameter of 19mm for standby use. The thickness of the composite solid electrolyte membrane was 40μm. Electrochemical tests showed that the room temperature ionic conductivity of the composite solid electrolyte was 0.01mS / cm, the electrochemical window was 4.0V, and the lithium ion migration number was 0.75. The preparation method of the positive electrode sheet is as follows: 80 mg of lithium iron phosphate positive electrode powder, 9 mg of PVDF binder, 1 mg of succinonitrile-LAGP composite solid electrolyte slurry and 10 mg of Super P conductive agent are uniformly dispersed in 100 mg of NMP solvent, ground in a mortar for 1 hour, coated on aluminum foil and vacuum dried at 100 ° C for 24 hours to obtain a lithium iron phosphate positive electrode sheet (loading 12 mg / cm 2), cut into discs with a diameter of 10 mm for later use. The preparation method of the solid electrolyte coating layer on the positive electrode surface is as follows: 1g of succinonitrile-LAGP composite solid electrolyte is evenly dispersed in 9g of NMP solvent, and stirred at a speed of 1500r / min at 45°C for 12h to obtain a uniform slurry. The prepared slurry is applied to the positive electrode by a coating method and then dried. The drying condition is vacuum drying at 100°C for 24h. Finally, a 2016-type button battery is assembled with lithium iron phosphate coated with a solid electrolyte as the positive electrode, metallic lithium as the negative electrode, and a solid electrolyte composite membrane as the electrolyte. It cannot be effectively cycled at a 1C rate.

[0078] Comparative Example 2:

[0079] In this comparative example, 0.6g of ethylene glycol and 1.2g of LLZTO powder were added to 10g of N,N-dimethylformamide, and magnetically stirred at 1500r / min for 4h at room temperature to obtain a suspension. The obtained suspension was stirred at 90°C at a speed of 500r / min for 12h to obtain an organic-inorganic composite solid electrolyte slurry. The slurry was placed in a vacuum oven at 100°C and dried for 24h to obtain an ethylene glycol-LLZTO composite solid electrolyte powder material. The ethylene glycol-LLZTO composite solid electrolyte was characterized by TEM, as shown in FIG. Figure 2 As shown, no amorphous layered structure can be observed on the LLZTO surface, indicating that ethylene glycol has not polymerized on the LLZTO surface to form a surface layer. 1g of organic-inorganic composite solid electrolyte powder was then evenly dispersed in 5g of DMF solvent and stirred at 45°C at 1500 rpm for 12 hours to obtain a uniform slurry. The slurry was coated on a cellulose membrane using a coating method and then vacuum dried at 100°C for 24 hours. After complete drying, an organic-inorganic composite solid electrolyte membrane was obtained, which was cut into 19mm diameter discs for later use. The thickness of the composite solid electrolyte membrane was 40μm. Electrochemical testing showed that the room temperature ionic conductivity of the composite solid electrolyte was 0.01mS / cm, which is much lower than that of the composite solid electrolyte in the embodiment, which can reach 0.1mS / cm. The electrochemical window was 4.0V, which is much lower than that of the composite solid electrolyte in the embodiment. The lithium ion transference number was 0.75, which is much lower than that of the composite solid electrolyte in the embodiment. The preparation method of the positive electrode sheet is as follows: 80 mg of lithium iron phosphate positive electrode powder, 9 mg of PVDF binder, 1 mg of ethylene glycol-LLZTO composite solid electrolyte slurry and 10 mg of Super P conductive agent are uniformly dispersed in 100 mg of NMP solvent, ground in a mortar for 1 hour, coated on aluminum foil and vacuum dried at 100 ° C for 24 hours to obtain a lithium iron phosphate positive electrode sheet (loading 12 mg / cm 2), cut into discs with a diameter of 10 mm for later use. The preparation method of the solid electrolyte coating layer on the positive electrode surface is as follows: 1g of ethylene glycol-LLZTO composite solid electrolyte is evenly dispersed in 9g of NMP solvent, stirred at 45°C at a speed of 1500r / min for 12h to obtain a uniform slurry. The prepared slurry is applied to the positive electrode by a coating method and then dried. The drying condition is vacuum drying at 100°C for 24h. Finally, a 2016-type button battery is assembled with lithium iron phosphate coated with a solid electrolyte as the positive electrode, metallic lithium as the negative electrode, and a solid electrolyte composite membrane as the electrolyte. The capacity retention rate after 53 cycles at a 1C rate is less than 80%.

[0080] Example 1:

[0081] In this embodiment, 0.5g of succinonitrile and 1g of lithium lanthanum zirconium tantalum oxide (LLZTO) powder were added to 10g of N,N-dimethylformamide and stirred at 1500r / min for 4h at room temperature to obtain a suspension. The obtained suspension was stirred at a constant speed of 500r / min at 90°C for 12h to polymerize succinonitrile on the surface of the inorganic solid electrolyte powder to obtain an organic-inorganic composite solid electrolyte slurry. The slurry was placed in a vacuum oven at 100°C and dried for 24h to obtain a succinonitrile-LLZTO composite solid electrolyte powder material. Then, 1g of the organic-inorganic composite solid electrolyte powder was evenly dispersed in 5g of DMF solvent and stirred at 1500r / min for 12h at 45°C to obtain a uniform slurry. The slurry was coated onto a cellulose membrane using a coating method and then vacuum-dried at 100°C for 24 hours. After complete drying, the organic-inorganic composite solid electrolyte membrane was obtained and cut into 19mm diameter discs for later use. The composite solid electrolyte membrane had a thickness of 40μm. Electrochemical testing showed that the room temperature ionic conductivity of the composite solid electrolyte was 0.11mS / cm, the electrochemical window reached 4.9V, and the lithium ion transference number was 0.92. A composite membrane prepared from LLZTO powder not composited with succinonitrile and cellulose membrane served as a control group. The positive electrode sheet was prepared by uniformly dispersing 80mg of lithium iron phosphate positive electrode powder, 9mg of PVDF binder, 1mg of succinonitrile-LLZTO composite solid electrolyte slurry, and 10mg of Super P conductive agent in 100mg of NMP solvent. After grinding in a mortar for 1 hour, the mixture was coated on aluminum foil and vacuum-dried at 100°C for 24 hours to obtain a lithium iron phosphate positive electrode sheet (loading 12mg / cm 2), cut into discs with a diameter of 10 mm for later use. The preparation method of the solid electrolyte coating layer on the positive electrode surface is as follows: 1g of succinonitrile-LLZTO composite solid electrolyte is evenly dispersed in 9g of NMP solvent, stirred at a speed of 1500r / min at 45°C for 12h to obtain a uniform slurry. The prepared slurry is coated on the positive electrode by a coating method and then dried. The drying condition is vacuum drying at 100°C for 24h. Finally, a 2016-type button battery is assembled with lithium iron phosphate coated with a solid electrolyte as the positive electrode, metallic lithium as the negative electrode, and a solid electrolyte composite membrane as the electrolyte. The capacity retention rate is 85% after 300 cycles at a rate of 1C.

[0082] Example 2:

[0083] In this example, 0.1g of isobutyronitrile and 1g of lithium lanthanum titanate (LLTO) powder were mixed in 5g of dimethyl sulfoxide (DMSO) and stirred at 1500 rpm for 4 hours at room temperature to produce a suspension. The resulting suspension was stirred at 3000 rpm for 72 hours at 45°C to polymerize the isobutyronitrile on the surface of the inorganic solid electrolyte powder, producing an organic-inorganic composite solid electrolyte slurry. The slurry was dried in a vacuum oven at 40°C for 72 hours to produce an isobutyronitrile-LLTO composite solid electrolyte powder material. 1g of the organic-inorganic composite solid electrolyte powder was then rolled onto a roller press at 300°C and 20 MPa to form a 500μm thick organic-inorganic composite solid electrolyte membrane. The membrane was then cut into 19mm diameter wafers for later use. Electrochemical testing revealed that the composite solid electrolyte had a room temperature ionic conductivity of 0.1mS / cm, an electrochemical window of 4.5V, and a lithium ion transference number of 0.9. The solid electrolyte membrane prepared by LLTO powder not compounded with isobutyronitrile was used as the control group. The preparation method of the positive electrode sheet is as follows: 210 mg of NCM622 positive electrode powder with a surface layer of isobutyronitrile as the precursor, 2.5 mg of PVDF binder, 25 mg of isobutyronitrile-LLTO composite solid electrolyte slurry and 25 mg of carbon nanofiber conductive agent were uniformly dispersed in NMP solvent, magnetically stirred for 4 hours, coated on aluminum foil and vacuum dried at 120°C for 24 hours to obtain NCM622 positive electrode sheet (loading of 12 mg / cm 2), cut into discs with a diameter of 10 mm for later use. The preparation method of the polymer surface layer on the surface of the positive electrode active material is as follows: 0.5g isobutyronitrile and 0.5g NCM622 powder are mixed in 2g NMP, and magnetic stirring is carried out at a speed of 1500r / min for 4h at room temperature to obtain a suspension. The obtained suspension is then stirred at a constant speed of 3000r / min at 45°C for 72h to polymerize isobutyronitrile on the surface of NCM622 powder to obtain an NCM622 suspension containing a surface layer. The suspension is placed in a vacuum oven at 40°C and dried for 72h to obtain an NCM622 powder material having a surface layer whose precursor is isobutyronitrile. The preparation method of the solid electrolyte coating layer on the positive electrode surface is as follows: 1g polyvinylidene fluoride-LiFSI-LLTO composite solid electrolyte is evenly dispersed in 9g NMP solvent, and stirred at a speed of 1500r / min at 45°C for 12h to obtain a uniform slurry. The prepared slurry was applied to the positive electrode and then dried at 100°C under vacuum for 24 hours. Finally, a 2032-type button cell was assembled using the solid electrolyte-coated NCM622 as the positive electrode, metallic lithium as the negative electrode, and the solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 84.94% after 300 cycles at a 1C rate.

[0084] Example 3:

[0085] In this example, 0.5g of methyl 2-cyanoacrylate and 1g of lithium lanthanum zirconium oxide (LLZO) powder were added to 10g of N-methyl pyrrolidone and stirred at 1500r / min for 4h at room temperature to obtain a suspension. The obtained suspension was stirred at a constant speed of 100r / min at 95°C for 10h to polymerize methyl 2-cyanoacrylate on the surface of the inorganic solid electrolyte powder to obtain an organic-inorganic composite solid electrolyte slurry. The slurry was placed in a vacuum oven at 120°C and dried for 36h to obtain a methyl 2-cyanoacrylate-LLZO composite solid electrolyte powder material. Then, 1g of the organic-inorganic composite solid electrolyte powder was evenly dispersed in 4g of N-methyl pyrrolidone solvent and stirred at 300°C at 3000r / min for 1h to obtain a uniform slurry. The slurry was cast onto a polyimide nonwoven membrane and then vacuum-dried at 300°C for 1 hour. After complete drying, the resulting organic-inorganic composite solid electrolyte membrane had a thickness of 100 μm and was cut into 19 mm diameter discs for later use. Electrochemical testing revealed a room-temperature ionic conductivity of 0.12 mS / cm, an electrochemical window of 4.6 V, and a lithium ion transference number of 0.9. A composite membrane prepared from LLZO powder not compounded with methyl 2-cyanoacrylate and a polyimide nonwoven membrane served as a control group. The positive electrode sheet was prepared by uniformly dispersing 80 mg of lithium nickel manganese oxide (LMM) cathode powder, 10 mg of PVDF binder, and 10 mg of Ketjen black conductive agent in NMP solvent. After grinding in a mortar for 1 hour, the resulting sheet was coated on aluminum foil and vacuum-dried at 100°C for 24 hours. The resulting LMM (loading 11 mg / cm) cathode sheet was obtained. 2 ), cut into discs with a diameter of 10 mm for later use. The preparation method of the solid electrolyte coating layer on the positive electrode surface is as follows: 1g of 2-methyl cyanoacrylate-LLZO composite solid electrolyte powder is evenly dispersed in 4g of N-methylpyrrolidone solvent, stirred at 300°C and 100r / min for 1h to prepare a uniform slurry, which is then applied to the positive electrode and dried. The drying condition is vacuum drying at 100°C for 24h. The preparation method of the negative electrode plate is as follows: the metallic lithium is heated to 180°C by a melting method to melt it, the stainless steel mesh is soaked in the molten metallic lithium, and the mixture is cooled to room temperature to obtain a lithium-stainless steel mesh composite plate with a loading of 12mg / cm 2 Finally, a 2016-type button battery was assembled with a sulfur-carbon composite coated with a solid electrolyte as the positive electrode, a lithium-stainless steel mesh composite negative electrode as the negative electrode, and a solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 87% after 300 cycles at a 1C rate.

[0086] Example 4:

[0087] In this example, 2g of acetonitrile and 1g of Li3OCl powder were added to 10g of dimethyl sulfoxide (DMSO) and magnetically stirred at 1500 rpm for 4 hours at room temperature to produce a suspension. The resulting suspension was stirred at 1000 rpm at 300°C for 1 hour to polymerize the acetonitrile on the surface of the inorganic solid electrolyte powder, producing an organic-inorganic composite solid electrolyte slurry. The slurry was then placed in a vacuum oven at 100°C and dried for 24 hours to produce an acetonitrile-Li3OCl composite solid electrolyte powder material. 1g of the organic-inorganic composite solid electrolyte powder was then evenly dispersed in 9g of DMSO solvent and stirred at 100 rpm at 45°C for 72 hours to produce a uniform slurry. The slurry was then coated onto an aramid nonwoven membrane using a tape casting method and dried at 40°C for 72 hours. After complete drying, an organic-inorganic composite solid electrolyte membrane was obtained. The composite solid electrolyte membrane had a thickness of 200μm. Electrochemical tests showed that the room temperature ionic conductivity of the composite solid electrolyte was 0.14 mS / cm, the electrochemical window reached 4.6 V, and the lithium ion migration number was 0.91. The composite membrane prepared by combining Li3OCl powder that was not compounded with acetonitrile and aramid non-woven membrane was used as the control group. The preparation method of the positive electrode sheet is as follows: 80 mg of lithium cobalt oxide positive electrode powder, 8 mg of PVDF binder, 2 mg of acetonitrile-Li3OCl composite solid electrolyte powder material and 10 mg of BLACK PEARLS 2000 conductive agent were uniformly dispersed in NMP solvent, ground in a mortar for 1 hour, coated on nickel foam, and vacuum dried at 100 ° C for 24 hours to obtain a lithium cobalt oxide positive electrode sheet (loading of 12 mg / cm 2 ). The preparation method of the solid electrolyte coating layer on the positive electrode surface is as follows: 1g of polybenzothiazole-Li3OCl composite solid electrolyte powder is evenly dispersed in 9g of NMP solvent, stirred at a speed of 100r / min and a temperature of 45°C for 72h to obtain a uniform slurry, which is then applied to the positive electrode and dried. The drying conditions are 100°C in vacuum for 24h. The preparation method of the negative electrode sheet is as follows: 80mg of graphite powder, 10mg of PVDF binder and 10mg of BLACK PEARLS 2000 conductive agent are evenly dispersed in NMP solvent, ground in a mortar for 1h, and then coated on nickel foam and dried in vacuum at 100°C for 24h (loading capacity is 12mg / cm 2 The composite anode is then prepared using a melting method: metallic lithium is heated to 180°C to melt, the negative electrode is immersed in the molten lithium, and then cooled to room temperature. Finally, a soft-pack battery is assembled using solid-electrolyte-coated lithium cobalt oxide as the positive electrode, graphite as the negative electrode, and a solid electrolyte composite membrane as the electrolyte. The battery exhibits a capacity retention rate of 80% after 50 cycles at a 1C rate.

[0088] Example 5:

[0089] In this embodiment, 3g of nonanenitrile and 0.3g of Li2SiO3 powder were added to 15g of hexamethylphosphoramide, and the suspension was prepared at room temperature at a speed of 1500r / min for 4h. The obtained suspension was stirred at a speed of 1000r / min at 95°C for 10h to polymerize nonanenitrile on the surface of the inorganic solid electrolyte powder to obtain an organic-inorganic composite solid electrolyte slurry. The slurry was placed in a vacuum oven at 300°C and dried for 24h to obtain a nonanenitrile-Li2SiO3 composite solid electrolyte powder material. Then, 1g of organic-inorganic composite solid electrolyte powder was evenly dispersed in 9g of hexamethylphosphoramide solvent and stirred at a speed of 1500r / min for 12h at 120°C to obtain a uniform slurry. The slurry was applied to a polypropylene nonwoven membrane using a spin coating method at a speed of 600 rpm / s and vacuum dried at 120°C for 18 hours. After complete drying, an organic-inorganic composite solid electrolyte membrane with a thickness of 50 μm was obtained, which was cut into discs with a diameter of 19 mm for later use. Electrochemical testing showed that the room temperature ionic conductivity of the composite solid electrolyte was 0.15 mS / cm, the electrochemical window reached 4.55 V, and the lithium ion transference number was 0.95. A composite membrane prepared by combining Li2SiO3 powder not compounded with nonanonitrile with polypropylene nonwoven membrane was used as a control group. The positive electrode sheet was prepared by uniformly dispersing 80 mg of NCM622 positive electrode powder, 7 mg of PVDF binder, 3 mg of nonanonitrile-Li2SiO3 composite solid electrolyte powder, and 10 mg of acetylene black conductive agent in NMP solvent. After grinding in a mortar for 1 hour, the membrane was coated on carbon-coated aluminum foil and vacuum dried at 120°C for 24 hours to obtain an NCM622 positive electrode sheet (loading 12 mg / cm 2 ), cut into discs with a diameter of 10 mm for later use. The preparation method of the solid electrolyte coating layer on the positive electrode surface is as follows: LLZO coating with a thickness of 200 nm is prepared on the surface of the positive electrode plate by magnetron sputtering. The preparation method of the negative electrode plate is as follows: 80 mg of hard carbon powder, 10 mg of PVDF binder and 10 mg of acetylene black conductive agent are uniformly dispersed in NMP solvent, ground in a mortar for 1 hour, coated on copper foil and vacuum dried at 120 ° C for 24 hours to obtain a hard carbon plate (loading of 12 mg / cm 2 ), cut into 10mm diameter discs for later use. Then, a lithium-containing composite negative electrode was prepared by electrochemical method, and a constant current method was used at 0.1mAcm -2 The hard carbon composite negative electrode was obtained by discharging the battery to a current density of 0.001 V. Finally, a 2016-type button battery was assembled using an NCM622 positive electrode with a solid electrolyte coating, a hard carbon negative electrode, and a solid electrolyte composite membrane as the electrolyte. The battery retained 94% of its capacity after 300 cycles at a 1C rate.

[0090] Example 6:

[0091] In this example, 0.5g of phthalonitrile and 1g of sodium lanthanum zirconium tantalum oxide powder were added to 10g of N,N-dimethylformamide and stirred at 1500 rpm for 4 hours at room temperature to produce a suspension. The resulting suspension was stirred at 90°C and 500 rpm for 12 hours to polymerize the succinonitrile on the surface of the inorganic solid electrolyte powder, producing an organic-inorganic composite solid electrolyte slurry. The slurry was dried in a vacuum oven at 100°C for 24 hours to produce a phthalonitrile-sodium lanthanum zirconium tantalum oxide composite solid electrolyte powder material. The organic-inorganic composite solid electrolyte powder was then pressed into an organic-inorganic composite solid electrolyte membrane disc with a thickness of 1μm and a diameter of 19mm using a press at 45°C and 101.3kPa for later use. Electrochemical testing revealed that the composite solid electrolyte had a room temperature ionic conductivity of 0.13mS / cm, an electrochemical window of 4.7V, and a sodium ion transference number of 0.93. The solid electrolyte membrane prepared from sodium lanthanum zirconium tantalum oxide powder not compounded with phthalonitrile was used as the control group. The preparation method of the positive electrode sheet is as follows: 80 mg of sodium vanadium phosphate positive electrode powder, 1 mg of PVDF binder, 10 mg of electrolyte slurry and 10 mg of Super P conductive agent are uniformly dispersed in NMP solvent, ground in a mortar for 1 hour, and then coated on aluminum foil and vacuum dried at 100 ° C for 24 hours to obtain a sodium vanadium phosphate positive electrode sheet (loading 12 mg / cm 2 ), cut into discs with a diameter of 10 mm for later use. The preparation method of the solid electrolyte coating layer on the positive electrode surface is as follows: 1g of phthalonitrile-sodium lanthanum zirconium tantalum oxide composite solid electrolyte powder is evenly dispersed in 9g of NMP solvent, and stirred at 80°C at a speed of 1500r / min for 12h to obtain a uniform slurry. It is then coated on the positive electrode and dried. The drying condition is vacuum drying at 100°C for 24h. Finally, a 2016-type button battery is assembled with sodium vanadium phosphate coated with a solid electrolyte as the positive electrode, metallic sodium as the negative electrode, and a solid electrolyte composite membrane as the electrolyte. The capacity retention rate is 89.4% after 300 cycles at a 1C rate.

[0092] Example 7:

[0093] In this example, 0.1 g of butyl 2-cyanoacrylate and 1 g of sodium lanthanum titanium oxide powder were mixed in 5 g of dimethyl sulfoxide and stirred at 1500 r / min for 4 hours at room temperature to produce a suspension. The resulting suspension was stirred at 3000 r / min for 72 hours at 45°C to polymerize butyl 2-cyanoacrylate on the surface of the inorganic solid electrolyte powder to produce an organic-inorganic composite solid electrolyte slurry. The slurry was placed in a vacuum oven at 40°C and dried for 72 hours to produce a butyl 2-cyanoacrylate-sodium lanthanum titanium oxide composite solid electrolyte powder material. The organic-inorganic composite solid electrolyte powder was then rolled on a roller press at 300°C and 20 MPa to prepare an organic-inorganic composite solid electrolyte membrane with a thickness of 500 μm, which was then cut into discs with a diameter of 19 mm for later use. Electrochemical tests showed that the room temperature ionic conductivity of the composite solid electrolyte was 0.12 mS / cm, the electrochemical window reached 4.8 V, and the sodium ion transference number was 0.92. A solid electrolyte membrane prepared from sodium lanthanum titanium oxide powder not composited with 2-butyl cyanoacrylate was used as a control group. The preparation method of the positive electrode sheet is: 200 mg Na 1.72 Mn[Fe(CN)6] 0.99 The cathode material powder, 25 mg PVDF binder and 25 mg carbon nanofiber conductive agent were uniformly dispersed in NMP solvent, magnetically stirred for 4 h, and then coated on aluminum foil and dried in vacuum at 120 ° C for 24 h to obtain Na 1.72 Mn[Fe(CN)6] 0.99 Positive electrode sheet (load is 12mg / cm 2 ), cut into 10mm diameter discs for later use. The preparation method of the negative electrode sheet is: using an electrochemical method with 0.1mAcm -2 The current density was discharged to 0.001V to prepare the sodium-containing carbon cloth negative electrode sheet with a loading of 12 mg / cm 2 , cut into 10mm diameter discs for later use. 1.72 Mn[Fe(CN)6] 0.99 A 2032-type button battery is assembled with a sodium-carbon cloth composite negative electrode as the positive electrode, a solid electrolyte composite membrane as the negative electrode, and a solid electrolyte composite membrane as the electrolyte. The capacity retention rate is 83% after 300 cycles at a 1C rate.

[0094] Example 8:

[0095] In this example, 0.5 g of benzonitrile and 1 g of NaAlO2 powder were added to 10 g of N-methylpyrrolidone and stirred at 1500 r / min for 4 hours at room temperature to produce a suspension. The resulting suspension was stirred at 100 r / min for 10 hours at 95°C to polymerize the benzonitrile on the surface of the inorganic solid electrolyte powder, producing an organic-inorganic composite solid electrolyte slurry. The slurry was dried in a vacuum oven at 120°C for 36 hours to produce a benzonitrile-NaAlO2 composite solid electrolyte powder material. 1 g of the organic-inorganic composite solid electrolyte powder was then evenly dispersed in 9 g of N-methylpyrrolidone solvent and stirred at 300°C for 1 hour to produce a uniform slurry. The slurry was then coated on a glass plate using a scraper and vacuum dried at 300°C for 1 hour to obtain an organic-inorganic composite solid electrolyte membrane. The thickness of the composite solid electrolyte membrane is 100 μm, and it is cut into discs with a diameter of 19 mm for later use. Electrochemical tests show that the room temperature ionic conductivity of the composite solid electrolyte is 0.15 mS / cm, the electrochemical window reaches 4.7 V, and the sodium ion migration number is 0.95. The solid electrolyte membrane prepared from NaAlO2 powder that is not compounded with benzonitrile is used as the control group. The preparation method of the benzonitrile positive electrode sheet is as follows: 80 mg Na3V2(PO4)2F3 positive electrode powder, 10 mg PVDF binder, 0.1 mg benzonitrile-NaAlO2 electrolyte slurry binder and 10 mg Ketjen carbon black conductive agent are uniformly dispersed in NMP solvent, ground in a mortar for 1 hour, coated on aluminum foil and vacuum dried at 100 ° C for 24 hours to obtain a positive electrode sheet (loading of 12 mg / cm 2 ), cut into discs with a diameter of 10 mm for later use. The preparation method of the solid electrolyte coating layer on the surface of the positive electrode is: the prepared benzonitrile-NaAlO2 composite solid electrolyte slurry is coated on the positive electrode and then dried, and the drying conditions are 100°C vacuum for 24 hours. The preparation method of the negative electrode plate is: 80 mg of hard carbon powder, 10 mg of PVDF binder and 10 mg of acetylene black conductive agent are uniformly dispersed in NMP solvent, ground in a mortar for 1 hour, and then coated on copper foil and dried in vacuum at 120°C for 24 hours to obtain a hard carbon negative electrode plate. The hard carbon-metal sodium composite negative electrode (loading of 12 mg / cm2) was prepared by roller pressing at 300°C and 20 MPa. 2 ), cut into 10mm diameter discs for later use. Finally, a 2016-type button cell was assembled using a solid electrolyte-coated Na₃V₂(PO₄)₂F₃ positive electrode, a hard carbon negative electrode, and a solid electrolyte composite membrane as the electrolyte. The battery maintained 87% of its capacity after 300 cycles at a 1C rate.

[0096] Example 9:

[0097] In this example, 2g of cyclopropyl nitrile and 1g of K3OCl powder were added to 10g of dimethyl sulfoxide (DMSO) and stirred at 1500 rpm for 4 hours at room temperature to produce a suspension. The resulting suspension was stirred at 1000 rpm for 1 hour at 300°C to polymerize the cyclopropyl nitrile on the surface of the inorganic solid electrolyte powder, producing an organic-inorganic composite solid electrolyte slurry. The slurry was dried in a vacuum oven at 100°C for 24 hours to produce a cyclopropyl nitrile-K3OCl composite solid electrolyte powder material. 2g of the organic-inorganic composite solid electrolyte powder was then evenly dispersed in 18g of DMSO solvent and stirred at 100 rpm for 72 hours at 45°C to produce a uniform slurry. The slurry was cast onto a polytetrafluoroethylene plate using a casting method and dried at 40°C for 72 hours. After complete drying, an organic-inorganic composite solid electrolyte membrane was obtained. The composite solid electrolyte membrane had a thickness of 200μm. Electrochemical tests showed that the room temperature ionic conductivity of the composite solid electrolyte was 0.1 mS / cm, the electrochemical window reached 4.5 V, and the potassium ion migration number was 0.9. The solid electrolyte membrane prepared from K3OCl powder that was not compounded with cyclopropyl nitrile was used as the control group. The preparation method of the positive electrode sheet is as follows: 80 mg of nickel-cobalt-manganese ternary positive electrode powder, 10 mg of PVDF binder, 0.01 mg of organic-inorganic composite solid electrolyte slurry and 10 mg of BLACK PEARLS2000 conductive agent were uniformly dispersed in NMP solvent, ground in a mortar for 1 hour, and then coated on nickel foam and dried in vacuum at 100 ° C for 24 hours to obtain a positive electrode sheet (loading of 12 mg / cm 2 ). The preparation method of the solid electrolyte coating layer on the positive electrode surface is as follows: 1g of organic-inorganic composite solid electrolyte powder is evenly dispersed in 9g of NMP solvent, stirred at 45°C at a speed of 100r / min for 72h, and a uniform slurry is obtained and then applied to the positive electrode and dried. The drying condition is vacuum drying at 100°C for 24h. The preparation method of the negative electrode plate is as follows: 80mg of silicon powder, 10mg of PVDF binder and 10mg of BLACKPEARLS2000 conductive agent are evenly dispersed in NMP solvent, ground in a mortar for 1h, coated on copper foil and vacuum dried at 100°C for 24h to obtain a negative electrode plate (loading capacity is 12mg / cm 2 ) A 500μm potassium sheet was pressed onto a silicon anode using a roller press at 300°C and 20MPa to prepare a silicon composite anode. Finally, a soft-pack battery was assembled using a solid-electrolyte-coated nickel-cobalt-manganese ternary cathode, a silicon composite anode, and a solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 88% after 30 cycles at a 1C rate.

[0098] Example 10:

[0099] In this example, 3g of butyronitrile and 0.3g of K2SiO3 powder were added to 20g of hexamethylphosphoramide and stirred at 1500r / min for 4h at room temperature to obtain a suspension. The resulting suspension was stirred at 1000r / min at 95°C for 10h to polymerize the butyronitrile on the surface of the inorganic solid electrolyte powder, thereby obtaining an organic-inorganic composite solid electrolyte slurry. The slurry was dried in a vacuum oven at 100°C for 24h to obtain a butyronitrile-K2SiO3 composite solid electrolyte powder material. 1g of the organic-inorganic composite solid electrolyte powder was then evenly dispersed in 9g of hexamethylphosphoramide solvent and stirred at 1500r / min for 12h at 120°C to obtain a uniform slurry. The slurry was then applied to a polypropylene non-woven membrane using a scraper and dried at 120°C for 18h. After complete drying, an organic-inorganic composite solid electrolyte membrane was obtained. The composite solid electrolyte membrane is 40 μm thick and is cut into discs with a diameter of 19 mm for later use. Electrochemical tests show that the room temperature ionic conductivity of the composite solid electrolyte is 0.12 mS / cm, the electrochemical window reaches 4.5 V, and the potassium ion transference number is 0.9. A composite membrane prepared by combining K2SiO3 powder not compounded with nitrile with polypropylene nonwoven membrane was used as the control group. The preparation method of the nitrile positive electrode is as follows: 85 mg K 1.72 Mn[Fe(CN)6] 0.99 The cathode powder, 7 mg PVDF binder, 3 mg nitrile-K2SiO3 electrolyte slurry and 10 mg acetylene black conductive agent were uniformly dispersed in NMP solvent, ground in a mortar for 1 h, and then coated on carbon-coated aluminum foil and dried in vacuum at 120 ° C for 24 h to obtain K 1.72 Mn[Fe(CN)6] 0.99 Positive electrode sheet (load is 12mg / cm 2 ), cut into 10mm diameter discs for later use. The preparation method of the positive electrode surface solid electrolyte coating layer is as follows: 1g of butyronitrile-K2SiO3 composite solid electrolyte powder is evenly dispersed in 9g of NMP solvent, stirred at 120℃ at a speed of 1500r / min for 12h, the obtained uniform slurry is coated on the positive electrode and then dried. The drying condition is vacuum drying at 100℃ for 24h. Finally, the K2SiO3 composite solid electrolyte is coated on the positive electrode. 1.72 Mn[Fe(CN)6] 0.99 The 2016-type button battery is assembled with a positive electrode, a metallic potassium negative electrode, and a solid electrolyte composite membrane as the electrolyte. The capacity retention rate is 94% after 300 cycles at a 1C rate.

[0100] Example 11:

[0101] In this example, 0.5 g of pimelonitrile and 1 g of lithium lanthanum zirconium tantalum oxide (LLZTO) powder were added to 10 g of N,N-dimethylformamide and stirred at a constant speed of 1500 r / min for 4 hours at room temperature to obtain a suspension. The resulting suspension was stirred at a constant speed of 500 r / min for 12 hours at 90°C to polymerize pimelonitrile on the surface of the inorganic solid electrolyte powder to obtain an organic-inorganic composite solid electrolyte slurry. The slurry was placed in a vacuum oven at 100°C and dried for 24 hours to obtain a pimelonitrile-LLZTO composite solid electrolyte powder material. 1 g of the organic-inorganic composite solid electrolyte powder was then evenly dispersed in 5 g of DMF solvent and stirred at 1500 r / min for 12 hours at 45°C to obtain a uniform slurry. The slurry was applied to a glass fiber membrane using a coating method and then vacuum-dried at 100°C for 24 hours. After complete drying, the resulting organic-inorganic composite solid electrolyte membrane was cut into 19 mm diameter discs for later use. The composite solid electrolyte membrane had a thickness of 40 μm. Electrochemical testing revealed a room-temperature ionic conductivity of 0.11 mS / cm, an electrochemical window of 4.9 V, and a lithium ion transference number of 0.92. A composite membrane prepared from LLZTO powder not compounded with pimelonitrile and glass fiber membrane served as a control. The preparation method of the positive electrode sheet is as follows: 80 mg of lithium manganate positive electrode powder with a surface layer of acrylonitrile as a precursor, 9 mg of styrene-butadiene rubber binder, 1 mg of pimelonitrile-LLZTO composite solid electrolyte slurry and 10 mg of Super P conductive agent are uniformly dispersed in 100 mg of NMP solvent, ground in a mortar for 1 hour, coated on aluminum foil and dried in vacuum at 100 ° C for 24 hours to obtain a lithium manganate positive electrode sheet (loading 12 mg / cm 2) and cut into 10mm diameter discs for later use. The polymer surface layer on the positive electrode active material is prepared by mixing 0.5g acrylonitrile and 0.5g lithium manganate powder in 2g NMP and stirring at 1500 r / min at room temperature for 4 hours to produce a suspension. The resulting suspension is stirred at 3000 r / min at 45°C for 72 hours to polymerize the acrylonitrile on the surface of the lithium manganate powder, producing a lithium manganate suspension containing a surface layer. The suspension is then dried in a vacuum oven at 40°C for 72 hours to produce a lithium manganate powder material with a surface layer composed of the acrylonitrile precursor. The solid electrolyte coating on the positive electrode surface is prepared by uniformly dispersing 1g of a poly(vinylidene fluoride-hexafluoropropylene)-LiTFSI-LLZO (mass ratio 1:1:1) composite solid electrolyte in 9g of NMP solvent and stirring at 1500 r / min at 45°C for 12 hours to produce a uniform slurry. The resulting slurry was then applied to the positive electrode and dried under vacuum at 100°C for 24 hours. The solid electrolyte coating on the negative electrode surface was prepared by uniformly dispersing 1g of a poly(vinylidene fluoride-hexafluoropropylene)-LiTFSI-LLZO (mass ratio 1:1:1) composite solid electrolyte in 9g of NMP solvent. The mixture was stirred at 45°C and 1500 rpm for 12 hours to obtain a uniform slurry. The resulting slurry was then applied to a lithium negative electrode and dried under vacuum at 100°C for 24 hours. Finally, a 2016-type button cell was assembled using the solid electrolyte-coated lithium manganese oxide as the positive electrode, metallic lithium as the negative electrode, and the solid electrolyte composite membrane as the electrolyte. The capacity retention was 85% after 300 cycles at a 1C rate.

[0102] Example 12:

[0103] In this example, 0.1 g of cyclobutane nitrile and 1 g of lithium lanthanum titanate (LLTO) powder were mixed in 4 g of dimethyl sulfoxide and stirred at 1500 rpm for 4 hours at room temperature to produce a suspension. The resulting suspension was stirred at 3000 rpm for 72 hours at 45°C to polymerize the cyclobutane nitrile on the surface of the inorganic solid electrolyte powder, producing an organic-inorganic composite solid electrolyte slurry. The slurry was dried in a vacuum oven at 40°C for 72 hours to produce a cyclobutane nitrile-LLTO composite solid electrolyte powder material. A roller press was then used to press 1 g of the organic-inorganic composite solid electrolyte powder at 300°C and 20 MPa to prepare an organic-inorganic composite solid electrolyte membrane with a thickness of 500 μm. The membrane was then cut into 19 mm diameter wafers for later use. Electrochemical testing showed that the room temperature ionic conductivity of the composite solid electrolyte was 0.1 mS / cm, the electrochemical window reached 4.5 V, and the lithium ion transference number was 0.9. The solid electrolyte membrane prepared from LLTO powder not compounded with cyclobutane nitrile was used as the control group. The preparation method of the positive electrode sheet is as follows: 210 mg of NCM811 positive electrode powder with a surface layer of phthalonitrile as the precursor, 2.5 mg of polytetrafluoroethylene binder, 25 mg of cyclobutane nitrile-LLTO composite solid electrolyte slurry and 25 mg of carbon nanofiber conductive agent were uniformly dispersed in NMP solvent, magnetically stirred for 4 hours, coated on aluminum foil and vacuum dried at 120°C for 24 hours to obtain NCM811 positive electrode sheet (loading of 12 mg / cm 2), cut into discs with a diameter of 10 mm for later use. The preparation method of the polymer surface layer on the surface of the positive electrode active material is to mix 0.5g of phthalonitrile and 0.5g of NCM811 powder in 2g of NMP, and stir at a speed of 1500r / min for 4h at room temperature to prepare a suspension. The obtained mixture suspension is stirred at a constant speed of 3000r / min at 45°C for 72h to polymerize the phthalonitrile on the surface of the NCM811 powder to prepare an NCM811 suspension containing a surface layer. The suspension is placed in a vacuum oven at 40°C and dried for 72h to obtain an NCM811 powder material having a surface layer whose precursor is phthalonitrile. The solid electrolyte coating on the positive electrode surface was prepared by uniformly dispersing 1g of a cellulose-LiBOB-LiBH4 (mass ratio 1:1:1) composite solid electrolyte into 9g of NMP solvent, stirring the mixture at 45°C at 1500 rpm for 12 hours to obtain a uniform slurry. The resulting slurry was then applied to the positive electrode and dried under vacuum at 100°C for 24 hours. The solid electrolyte coating on the negative electrode surface was prepared by uniformly dispersing 1g of a cellulose-LiBOB-LiBH4 (mass ratio 1:1:1) composite solid electrolyte into 9g of NMP solvent, stirring the mixture at 45°C at 1500 rpm for 12 hours to obtain a uniform slurry. The resulting slurry was then applied to the lithium negative electrode and dried under vacuum at 100°C for 24 hours. Finally, a 2032-type button battery was assembled with NCM811 coated with solid electrolyte as the positive electrode, metallic lithium as the negative electrode, and solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 84.94% after 300 cycles at a 1C rate.

[0104] Example 13:

[0105] In this example, 0.5g of ethyl 2-cyanoacrylate and 1g of lithium lanthanum zirconium oxide (LLZO) powder were added to 10g of N-methylpyrrolidone and stirred at a constant speed of 1500r / min for 4h at room temperature to prepare a suspension. The resulting suspension was stirred at a constant speed of 100r / min at 95°C for 10h to polymerize ethyl 2-cyanoacrylate on the surface of the inorganic solid electrolyte powder to prepare an organic-inorganic composite solid electrolyte slurry. The slurry was placed in a vacuum oven at 120°C and dried for 36h to prepare a 2-ethyl cyanoacrylate-LLZO composite solid electrolyte powder material. 1g of the organic-inorganic composite solid electrolyte powder was then evenly dispersed in 4g of N-methylpyrrolidone solvent and stirred at 300°C at 3000r / min for 1h to prepare a uniform slurry. The slurry was cast onto a polydifluorostyrene sulfonic acid (PDSSA) membrane using a casting method and then vacuum-dried at 300°C for 1 hour. After complete drying, an organic-inorganic composite solid electrolyte membrane was obtained. The composite solid electrolyte membrane had a thickness of 100 μm and was cut into 19 mm diameter discs for later use. Electrochemical testing revealed a room-temperature ionic conductivity of 0.12 mS / cm, an electrochemical window of 4.6 V, and a lithium ion transference number of 0.9. A composite membrane prepared from LLZO powder not compounded with ethyl 2-cyanoacrylate and PDSSA membrane served as a control group. The preparation method of the positive electrode sheet is as follows: 80 mg of lithium nickel manganese oxide positive electrode powder with a surface layer of 2-octyl cyanoacrylate as a precursor, 10 mg of sodium carboxymethyl cellulose binder and 10 mg of Ketjen black conductive agent are uniformly dispersed in NMP solvent, ground in a mortar for 1 hour, coated on aluminum foil and dried in vacuum at 100°C for 24 hours to obtain a lithium nickel manganese oxide positive electrode sheet (loading 12 mg / cm 2), cut into discs with a diameter of 10 mm for later use. The preparation method of the polymer surface layer on the surface of the positive electrode active material is to mix 0.5g of 2-octyl cyanoacrylate and 0.5g of lithium nickel manganese oxide powder in 2g of NMP, and stir at a speed of 1500r / min for 4 hours at room temperature to obtain a suspension. The obtained suspension is stirred at a speed of 3000r / min at 45°C for 72 hours to polymerize 2-octyl cyanoacrylate on the surface of the lithium nickel manganese oxide powder to obtain a lithium nickel manganese oxide suspension containing a surface layer. The suspension is placed in a vacuum oven at 40°C and dried for 72 hours to obtain a lithium nickel manganese oxide powder material having a surface layer whose precursor is 2-octyl cyanoacrylate. The solid electrolyte coating layer on the positive electrode surface was prepared by uniformly dispersing 1g of epoxy resin-LiPF6-Li3OCl (mass ratio 1:1:1) composite solid electrolyte powder into 4g of N-methylpyrrolidone solvent, stirring at 300°C and 3000 rpm for 1 hour to prepare a uniform slurry, which was then applied to the positive electrode and dried under vacuum at 100°C for 24 hours. The solid electrolyte coating layer on the negative electrode surface was prepared by uniformly dispersing 1g of epoxy resin-LiPF6-Li3OCl (mass ratio 1:1:1) composite solid electrolyte powder into 4g of N-methylpyrrolidone solvent, stirring at 300°C and 3000 rpm for 1 hour to prepare a uniform slurry, which was then applied to the lithium negative electrode and dried under vacuum at 100°C for 24 hours. Finally, a 2016-type button battery was assembled with lithium nickel manganese oxide coated with a solid electrolyte as the positive electrode, metallic lithium as the negative electrode, and a solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 87% after 300 cycles at a 1C rate.

[0106] Example 14:

[0107] In this example, 2g of benzyl propionitrile and 1g of Li3OCl powder were added to 10g of dimethyl sulfoxide (DMSO) and stirred at 1500 r / min for 4 hours at room temperature to produce a suspension. The resulting suspension was stirred at 1000 r / min for 1 hour at 300°C to polymerize the benzyl propionitrile on the surface of the inorganic solid electrolyte powder, producing an organic-inorganic composite solid electrolyte slurry. The slurry was dried in a vacuum oven at 100°C for 24 hours to produce a benzyl propionitrile-Li3OCl composite solid electrolyte powder material. 1g of the organic-inorganic composite solid electrolyte powder was then evenly dispersed in 9g of DMSO solvent and stirred at 100 r / min for 72 hours at 45°C to produce a uniform slurry. The slurry was then coated onto a PP film using a tape casting method and dried at 40°C for 72 hours. After complete drying, an organic-inorganic composite solid electrolyte membrane was obtained. The composite solid electrolyte membrane had a thickness of 200μm. Electrochemical tests showed that the room temperature ionic conductivity of the composite solid electrolyte was 0.14 mS / cm, the electrochemical window reached 4.6 V, and the lithium ion migration number was 0.91. The composite membrane prepared by compounding Li3OCl powder that was not compounded with phenylpropionitrile and PP film was used as the control group. The preparation method of the positive electrode sheet is as follows: 80 mg of lithium cobalt oxide positive electrode powder with a surface layer whose precursor is 2-cyanoacrylate propyl ester, 8 mg of polyethylene binder, 2 mg of phenylpropionitrile-Li3OCl composite solid electrolyte powder material and 10 mg of BLACK PEARLS 2000 conductive agent were uniformly dispersed in NMP solvent, ground in a mortar for 1 hour, coated on nickel foam, and vacuum dried at 100 ° C for 24 hours to obtain a lithium cobalt oxide positive electrode sheet (loading of 12 mg / cm 2). The preparation method of the polymer surface layer on the surface of the positive electrode active material is to mix 0.5g of 2-cyanoacrylate propyl ester and 0.5g of lithium cobalt oxide powder in 2g of NMP, and stir at a speed of 1500r / min at room temperature for 4h to prepare a suspension. The obtained suspension is stirred at a speed of 3000r / min at 45°C for 72h to polymerize 2-cyanoacrylate propyl ester on the surface of the lithium cobalt oxide powder to prepare a lithium cobalt oxide suspension containing a surface layer. The suspension is placed in a vacuum oven at 40°C and dried for 72h to obtain a lithium cobalt oxide powder material having a surface layer whose precursor is 2-cyanoacrylate propyl ester. The solid electrolyte coating on the positive electrode surface was prepared by uniformly dispersing 1g of polybenzothiazole-LiClO4-Li3InCl6 (mass ratio 1:1:1) composite solid electrolyte powder into 9g of NMP solvent. The mixture was stirred at 45°C and 100 rpm for 72 hours to obtain a uniform slurry, which was then applied to the positive electrode and dried at 100°C in a vacuum oven for 24 hours. The negative electrode sheet was prepared by uniformly dispersing 80mg of amorphous carbon powder, 10mg of styrene-butadiene rubber binder, and 10mg of BLACK PEARLS 2000 conductive agent in acetone. After grinding in a mortar for 1 hour, the mixture was coated onto titanium foil and dried in a vacuum oven at 100°C for 24 hours. The composite negative electrode was then prepared using a melt process. Lithium metal was heated to 180°C to melt, and the negative electrode sheet was immersed in the molten lithium metal. After cooling to room temperature, the amorphous carbon composite negative electrode was obtained. Finally, a cylindrical battery was assembled with lithium cobalt oxide coated with solid electrolyte as the positive electrode, amorphous carbon as the negative electrode, and solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 80% after 50 cycles at a 1C rate.

[0108] Example 15:

[0109] In this example, 3g of glutaronitrile and 0.3g of Li2SiO3 powder were added to 20g of hexamethylphosphoramide and stirred at 1500r / min for 4h at room temperature to obtain a suspension. The resulting suspension was stirred at 1000r / min at 95°C for 10h to polymerize glutaronitrile on the surface of the inorganic solid electrolyte powder to obtain an organic-inorganic composite solid electrolyte slurry. The slurry was placed in a vacuum oven at 300°C and dried for 24h to obtain a glutaronitrile-Li2SiO3 composite solid electrolyte powder material. 1g of the organic-inorganic composite solid electrolyte powder was then evenly dispersed in 9g of hexamethylphosphoramide solvent and stirred at 1500r / min for 12h at 120°C to obtain a uniform slurry. The slurry was spin-coated at 600 rpm / s onto a perfluorosulfonic acid-polytetrafluoroethylene membrane and vacuum-dried at 120°C for 18 hours. After complete drying, a 50-μm-thick organic-inorganic composite solid electrolyte membrane was obtained, which was cut into 19-mm-diameter discs for later use. Electrochemical testing revealed a room-temperature ionic conductivity of 0.15 mS / cm, an electrochemical window of 4.55 V, and a lithium-ion transference number of 0.95. A control membrane was prepared by combining Li₂SiO₃ powder uncompounded with glutaronitrile with the perfluorosulfonic acid-polytetrafluoroethylene membrane. The preparation method of the positive electrode sheet is as follows: 80 mg of lithium manganese iron phosphate positive electrode powder, 7 mg of PVDF binder, 3 mg of glutaronitrile-Li2SiO3 composite solid electrolyte powder and 10 mg of acetylene black conductive agent are uniformly dispersed in NMP solvent, ground in a mortar for 1 hour, and then coated on carbon-coated aluminum foil and dried in vacuum at 120°C for 24 hours to obtain lithium manganese iron phosphate positive electrode sheet (loading 12 mg / cm 2 ), cut into discs with a diameter of 10 mm for later use. The preparation method of the solid electrolyte coating layer on the surface of the positive electrode is: the LLTO coating with a thickness of 200 nm is prepared on the surface of the positive electrode by magnetron sputtering. The preparation method of the negative electrode is: 80 mg of mesophase carbon microsphere powder, 10 mg of polytetrafluoroethylene binder and 10 mg of acetylene black conductive agent are evenly dispersed in cyclohexane solvent, ground in a mortar for 1 hour, coated on copper foil and vacuum dried at 120 ° C for 24 hours to obtain the mesophase carbon microsphere electrode, which is cut into discs with a diameter of 10 mm for later use. The lithium-containing composite negative electrode is then prepared by an electrochemical method, and a constant current method is used at 0.1 mA / cm -2 The composite negative electrode was prepared by discharging the battery to a current density of 0.001 V. Finally, a 2016-type button cell was assembled using a solid electrolyte-coated lithium iron manganese phosphate positive electrode, a mesophase carbon microbead negative electrode, and a solid electrolyte composite membrane as the electrolyte. The battery maintained a capacity of 94% after 300 cycles at a 1C rate.

[0110] Example 16:

[0111] In this example, 0.5 g of cycloheptyl nitrile and 1 g of sodium lanthanum zirconium tantalum oxide powder were added to 10 g of N,N-dimethylformamide and stirred at 1500 rpm for 4 hours at room temperature to produce a suspension. The resulting suspension was stirred at 90°C and 500 rpm for 12 hours to polymerize the succinonitrile on the surface of the inorganic solid electrolyte powder, producing an organic-inorganic composite solid electrolyte slurry. The slurry was dried in a vacuum oven at 100°C for 24 hours to produce a cycloheptyl nitrile-sodium lanthanum zirconium tantalum oxide composite solid electrolyte powder material. The organic-inorganic composite solid electrolyte powder was then pressed into an organic-inorganic composite solid electrolyte membrane disc with a thickness of 1 μm and a diameter of 19 mm using a press at 45°C and 101.3 kPa for later use. Electrochemical testing revealed that the composite solid electrolyte had a room temperature ionic conductivity of 0.13 mS / cm, an electrochemical window of 4.7 V, and a sodium ion transference number of 0.93. The solid electrolyte membrane prepared from sodium lanthanum zirconium tantalum oxide powder not compounded with cycloheptyl nitrile was used as the control group. The preparation method of the positive electrode sheet is as follows: 80 mg of sodium manganate positive electrode powder with a surface layer of cyclohexyl nitrile as the precursor, 1 mg of PVDF binder, 10 mg of electrolyte slurry and 10 mg of Super P conductive agent were uniformly dispersed in NMP solvent, ground in a mortar for 1 hour, and then coated on aluminum foil and dried in vacuum at 100°C for 24 hours to obtain a sodium manganate positive electrode sheet (loading of 12 mg / cm 2 ), cut into discs with a diameter of 10 mm for later use. The preparation method of the polymer surface layer on the surface of the positive electrode active material is to mix 0.5g of cyclohexyl nitrile and 0.5g of sodium manganate positive electrode powder in 2g of NMP, and stir at a speed of 1500r / min for 4h at room temperature to prepare a suspension. The obtained suspension is stirred at a speed of 3000r / min at 45°C for 72h to polymerize cyclohexyl nitrile on the surface of the sodium manganate positive electrode powder to prepare a sodium manganate suspension containing a surface layer. The suspension is placed in a vacuum oven at 40°C and dried for 72h to obtain a sodium manganate powder material having a surface layer whose precursor is cyclohexyl nitrile. The preparation method of the solid electrolyte coating layer on the positive electrode surface is: a sodium lanthanum zirconium oxide coating with a thickness of 200nm is prepared on the surface of the positive electrode piece by magnetron sputtering. The solid electrolyte coating on the negative electrode surface was prepared by magnetron sputtering a 200nm-thick sodium lanthanum zirconium oxide coating on the sodium negative electrode surface. Finally, a 2016-type button cell was assembled using the solid electrolyte-coated sodium manganate as the positive electrode, metallic sodium as the negative electrode, and the solid electrolyte composite membrane as the electrolyte. The battery demonstrated a capacity retention of 89.4% after 300 cycles at a 1C rate.

[0112] Example 17:

[0113] In this embodiment, 0.1g of azelaic acid and 1g of sodium lanthanum titanium oxide powder were mixed in 5g of dimethyl sulfoxide and stirred at a speed of 1500r / min for 4h at room temperature to obtain a suspension. The obtained suspension was stirred at a speed of 3000r / min at 45°C for 72h to polymerize azelaic acid on the surface of the inorganic solid electrolyte powder to obtain an organic-inorganic composite solid electrolyte slurry. The slurry was placed in a vacuum oven at 40°C and dried for 72h to obtain azelaic acid-sodium lanthanum titanium oxide composite solid electrolyte powder material. The organic-inorganic composite solid electrolyte powder was then prepared into an organic-inorganic composite solid electrolyte membrane with a thickness of 500μm at 300°C and 20MPa using a roller press, and cut into discs with a diameter of 19mm for later use. Electrochemical tests showed that the room temperature ionic conductivity of the composite solid electrolyte was 0.12mS / cm, the electrochemical window reached 4.8V, and the sodium ion migration number was 0.92. The solid electrolyte membrane prepared by sodium lanthanum titanium oxide powder not compounded with azelaic acid nitrile was used as the control group. 1.81 Ni[Fe(CN)6] 0.97 Prussian blue cathode material powder, 25 mg PVDF binder and 25 mg carbon nanofiber conductive agent were uniformly dispersed in NMP solvent, magnetically stirred for 4 h, and then coated on aluminum foil and dried in vacuum at 120 ° C for 24 h to obtain Na 1.81 Ni[Fe(CN)6] 0.97 Positive electrode sheet (load is 12mg / cm 2 ), cut into 10mm diameter discs for later use. The preparation method of the positive electrode surface solid electrolyte coating layer is: a sodium lanthanum titanium oxide coating is prepared on the surface of the positive electrode by evaporation method, with a thickness of 200nm. The preparation method of the negative electrode surface solid electrolyte coating layer is: a sodium lanthanum titanium oxide coating is prepared on the surface of the sodium negative electrode by evaporation method, with a thickness of 200nm. Finally, Na 1.81 Ni[Fe(CN)6] 0.97 A 2032-type button battery is assembled with sodium hydroxide as the positive electrode, metallic sodium as the negative electrode, and a solid electrolyte composite membrane as the electrolyte. The capacity retention rate is 83% after 300 cycles at a 1C rate.

[0114] Example 18:

[0115] In this example, 0.5 g of adiponitrile and 1 g of NaAlO2 powder were added to 10 g of N-methylpyrrolidone and stirred at 1500 r / min for 4 hours at room temperature to produce a suspension. The resulting suspension was stirred at 95°C at 100 r / min for 10 hours to polymerize adiponitrile on the surface of the inorganic solid electrolyte powder, producing an organic-inorganic composite solid electrolyte slurry. The slurry was dried in a vacuum oven at 120°C for 36 hours to produce an adiponitrile-NaAlO2 composite solid electrolyte powder material. 1 g of the organic-inorganic composite solid electrolyte powder was then evenly dispersed in 9 g of N-methylpyrrolidone solvent and stirred at 300°C at 3000 r / min for 1 hour to produce a uniform slurry. The slurry was then coated on a glass plate using a scraper and then vacuum dried at 300°C for 1 hour to produce an organic-inorganic composite solid electrolyte membrane. The thickness of the composite solid electrolyte membrane is 100 μm, and it is cut into discs with a diameter of 19 mm for later use. Electrochemical tests show that the room temperature ionic conductivity of the composite solid electrolyte is 0.15 mS / cm, the electrochemical window reaches 4.7 V, and the sodium ion migration number is 0.95. The solid electrolyte membrane prepared from NaAlO2 powder that is not compounded with adiponitrile is used as the control group. The preparation method of the positive electrode sheet is as follows: 80 mg of sodium manganese phosphate positive electrode powder, 10 mg of PVDF binder, 0.1 mg of adiponitrile-NaAlO2 electrolyte slurry binder and 10 mg of Ketjen carbon black conductive agent are uniformly dispersed in NMP solvent, ground in a mortar for 1 hour, coated on aluminum foil and vacuum dried at 100 ° C for 24 hours to obtain a positive electrode sheet (loading of 12 mg / cm 2 ) and cut into 10mm diameter discs for later use. The solid electrolyte coating on the positive electrode surface was prepared by uniformly dispersing 1g of polybenzothiazole-NaClO4-Na3InCl6 (mass ratio 1:1:1) composite solid electrolyte powder in 9g of NMP solvent. The mixture was stirred at 45°C at 100 rpm for 72 hours to obtain a uniform slurry, which was then applied to the positive electrode and dried at 100°C in a vacuum oven for 24 hours. The negative electrode sheet was prepared by uniformly dispersing 80mg of tin-silicon alloy powder, 10mg of sodium carboxymethyl cellulose binder, and 10mg of acetylene black conductive agent in ethanol solvent. After grinding in a mortar for 1 hour, the mixture was coated on copper foil and dried in a vacuum oven at 120°C for 24 hours to obtain a tin-silicon alloy negative electrode sheet. A tin-silicon alloy-sodium metal composite negative electrode was prepared by roller pressing at 300°C and 20 MPa and cut into 10mm diameter discs for later use. Finally, a 2016-type button battery was assembled using a sodium manganese phosphate positive electrode coated with a solid electrolyte, a tin-silicon alloy negative electrode, and a solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 87% after 300 cycles at a 1C rate.

[0116] Example 19:

[0117] In this example, 2g of benzyl cyanide and 1g of K3OCl powder were added to 10g of dimethyl sulfoxide (DMSO) and stirred at 1500r / min for 4h at room temperature to obtain a suspension. The resulting suspension was stirred at 1000r / min for 1h at 300°C to polymerize the benzyl cyanide on the surface of the inorganic solid electrolyte powder, thereby obtaining an organic-inorganic composite solid electrolyte slurry. The slurry was dried in a vacuum oven at 100°C for 24h to obtain a benzyl cyanide-K3OCl composite solid electrolyte powder material. 2g of the organic-inorganic composite solid electrolyte powder was then evenly dispersed in 18g of dimethyl sulfoxide (DMSO) solvent and stirred at 100r / min for 72h at 45°C to obtain a uniform slurry. The slurry was cast onto a stainless steel plate using a casting method and dried at 40°C for 72h. After complete drying, an organic-inorganic composite solid electrolyte membrane was obtained, with a thickness of 200μm. Electrochemical tests showed that the room temperature ionic conductivity of the composite solid electrolyte was 0.1 mS / cm, the electrochemical window reached 4.5 V, and the potassium ion migration number was 0.9. The solid electrolyte membrane prepared from K3OCl powder that was not composited with benzyl cyanide was used as the control group. The preparation method of the positive electrode sheet is as follows: 80 mg of nickel-cobalt-manganese positive electrode powder glutaronitrile glutaronitrile glutaronitrile glutaronitrile with a surface layer whose precursor is glutaronitrile, 10 mg of PVDF binder, 0.01 mg of organic-inorganic composite solid electrolyte slurry and 10 mg of BLACK PEARLS 2000 conductive agent were uniformly dispersed in NMP solvent, ground in a mortar for 1 hour, and then coated on nickel foam and dried in vacuum at 100°C for 24 hours to obtain a positive electrode sheet (loading of 12 mg / cm 2). The preparation method of the polymer surface layer on the surface of the positive electrode active material is to mix 0.5g of glutaronitrile and 0.5g of nickel-cobalt-manganese positive electrode powder in 2g of NMP, and stir at a speed of 1500r / min for 4 hours at room temperature to obtain a suspension. The obtained suspension is stirred at a speed of 3000r / min at 45°C for 72 hours to polymerize glutaronitrile on the surface of the nickel-cobalt-manganese positive electrode powder to obtain a nickel-cobalt-manganese suspension containing a surface layer. The suspension is placed in a vacuum oven at 40°C and dried for 72 hours to obtain a nickel-cobalt-manganese powder material having a surface layer whose precursor is glutaronitrile. The solid electrolyte coating on the positive electrode surface was prepared by uniformly dispersing 1g of polyethylene carbonate-KClO4 (mass ratio 1:1) composite solid electrolyte powder in 9g of NMP solvent. The mixture was stirred at 45°C at 100 rpm for 72 hours to obtain a uniform slurry, which was then applied to the positive electrode and dried under vacuum at 100°C for 24 hours. The negative electrode sheet was prepared by uniformly dispersing 80mg of copper-silicon alloy powder, 10mg of polyolefin binder, and 10mg of BLACKPEARLS 2000 conductive agent in tetrahydrofuran solvent. After grinding in a mortar for 1 hour, the mixture was coated on titanium foil and dried under vacuum at 100°C for 24 hours to obtain the negative electrode sheet. The solid electrolyte coating on the negative electrode surface was prepared by uniformly dispersing 1g of polyethylene carbonate-KClO4 (mass ratio 1:1) composite solid electrolyte powder in 9g of NMP solvent. The mixture was stirred at 100 rpm for 72 hours at 45°C to obtain a uniform slurry, which was then applied to the negative electrode and dried at 100°C in a vacuum for 24 hours. Finally, a soft-pack battery was assembled using the nickel-cobalt-manganese ternary electrode coated with the solid electrolyte as the positive electrode, a copper-silicon alloy as the negative electrode, and the solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 88% after 30 cycles at a 1C rate.

[0118] Example 20:

[0119] In this example, 3g of tetracyanoethylene and 0.3g of K2SiO3 powder were added to 20g of hexamethylphosphoramide and stirred at 1500 rpm for 4 hours at room temperature to obtain a suspension. The resulting suspension was stirred at 1000 rpm for 10 hours at 95°C to polymerize the tetracyanoethylene on the surface of the inorganic solid electrolyte powder, thereby producing an organic-inorganic composite solid electrolyte slurry. The slurry was dried in a vacuum oven at 100°C for 24 hours to obtain a tetracyanoethylene-K2SiO3 composite solid electrolyte powder material. 1g of the organic-inorganic composite solid electrolyte powder was then evenly dispersed in 9g of hexamethylphosphoramide solvent and stirred at 1500 rpm for 12 hours at 120°C to obtain a uniform slurry. The slurry was then applied to a Nafion membrane using a scraper and dried at 120°C for 18 hours. Once completely dried, the organic-inorganic composite solid electrolyte membrane was obtained. The composite solid electrolyte membrane is 40 μm thick and is cut into 19 mm diameter discs for later use. Electrochemical testing shows that the room temperature ionic conductivity of the composite solid electrolyte is 0.12 mS / cm, the electrochemical window reaches 4.5 V, and the potassium ion transference number is 0.9. A composite membrane prepared by combining K2SiO3 powder not compounded with tetracyanoethylene with Nafion membrane was used as a control group. The positive electrode sheet was prepared as follows: 85 mg K 1.81 Ni[Fe(CN)6] 0.97 The positive electrode powder, 7 mg PVDF binder, 3 mg tetracyanoethylene-K2SiO3 electrolyte slurry and 10 mg acetylene black conductive agent were uniformly dispersed in NMP solvent, ground in a mortar for 1 h, and then coated on carbon-coated aluminum foil and dried in vacuum at 120 ° C for 24 h to obtain a Prussian blue positive electrode sheet (loading 12 mg / cm 2 ), cut into discs with a diameter of 10 mm for later use. The preparation method of the solid electrolyte coating layer on the positive electrode surface is: evenly disperse 1g Nafion in 9g NMP solvent, stir at 120°C at a speed of 1500r / min for 12h, obtain a uniform slurry and apply it to the positive electrode after drying, and the drying condition is 100°C vacuum drying for 24h. The preparation method of the solid electrolyte coating layer on the negative electrode surface is: evenly disperse 1g Nafion in 9g NMP solvent, stir at 120°C at a speed of 1500r / min for 12h, obtain a uniform slurry and apply it to the negative electrode after drying, and the drying condition is 100°C vacuum drying for 24h. Finally, the solid electrolyte K 1.81 Ni[Fe(CN)6] 0.97 The 2016-type button battery is assembled with a positive electrode, a metallic potassium negative electrode, and a solid electrolyte composite membrane as the electrolyte. The capacity retention rate is 94% after 300 cycles at a 1C rate.

Claims

1. An organic-inorganic composite solid electrolyte, characterized in that: The organic-inorganic composite solid electrolyte is composed of an inorganic oxide solid electrolyte that can conduct alkali metal cations and a polymer containing C=N and / or CN groups formed by in-situ polymerization on its surface; the mass ratio of the inorganic oxide solid electrolyte to the polymer is 1:0.1-10; The inorganic oxide solid electrolyte comprises A x MO y , one or more of garnet-type inorganic solid electrolytes, perovskite-type inorganic solid electrolytes and antiperovskite-type inorganic solid electrolytes; The A x MO y Type inorganic solid electrolyte, wherein 0.6≤x≤5, 1<y≤4, A is one or more of Li, Na or K, and M is one or more of Si, B, Ge, Zr, Al, Ga, Ti, P, S, As, Se, Nb, Sn, Sb, Te, Nd, Y, I, and La; The garnet-type inorganic solid electrolyte comprises A 7-m La3Zr 2-m M m O 12 、A 7-2n La3Zr 2-n N n O 12 and A 7- 3d D d La3Zr2O 12 , wherein 0≤m≤2, 0≤n≤2, 0≤d<7 / 3, A is one or more of Li, Na or K, M is one or two of Ta and Nb, N is one or two of W and Mo, and D is one or two of Ga and Al; The perovskite inorganic solid electrolyte is A 3x La 0.67-x TiO3, wherein 0.04<x<0.17, and A is one or more of Li, Na, or K; The antiperovskite inorganic solid electrolyte is A3OX, wherein A is one or more of Li, Na or K, and X is one or more of Cl, Br or I; The particle size of the oxide solid electrolyte is 1nm~100μm; the room temperature ionic conductivity is not less than 10 -4 mS / cm; the ratio of the number of charges transported by alkali metal cations in oxide solid electrolytes to the total number of charges transported by anions and cations is 1; The general structural formula of the polymer containing C=N and CN groups is: Where R1-R 12 Each of them is independently one or more of a C2-C8 alkyl group, a C1-C8 alkylene group, a 3-7 membered cycloalkyl group, an aryl group or a C3-C6 acrylate group, wherein 5≤n≤500, 5≤x+y+z≤500, and n, x, y and z are all integers greater than or equal to zero.

2. The method for preparing the organic-inorganic composite solid electrolyte according to claim 1, wherein: The mass ratio of the inorganic oxide solid electrolyte to the polymer is 1:0.5-5.

3. The method for preparing the organic-inorganic composite solid electrolyte according to claim 1, wherein: The polymer precursor is mixed with an inorganic oxide solid electrolyte powder material. The oxygen atoms on the surface of the inorganic oxide solid electrolyte, which are Lewis bases, catalyze the polymerization reaction of the polymer precursor, thereby in-situ generating a polymer containing C=N and / or CN groups on the surface of the inorganic oxide solid electrolyte. The specific preparation process includes the following steps: (1) fully mixing an oxide solid electrolyte powder material and a polymer precursor in an organic solvent to prepare a suspension; the mass ratio of the oxide solid electrolyte to the polymer precursor is 1:0.1 to 10; the mass ratio of the organic solvent to the polymer precursor is 5 to 50:1; (2) stirring the mixture suspension prepared in step (1) at a speed of 100 to 3000 r / min and a temperature of 45° C. to 300° C. for 1 to 72 h; (3) drying the mixture containing the organic-inorganic composite solid electrolyte obtained in step (2) at a temperature of 40 to 300° C. for a drying time of not less than 24 hours to obtain an organic-inorganic composite solid electrolyte powder material.

4. The preparation method according to claim 3, wherein: In step (2), the rotation speed is 1200-1600 r / min, the temperature is 85-95° C., and the time is 8-16 h.

5. The preparation method according to claim 3, wherein: The polymer precursor in step (1) is an organic compound having a nitrogen-containing unsaturated bond, including one or more of propionitrile, butyronitrile, valeronitrile, capronitrile, heptanenitrile, octanonitrile, nonanenitrile, sunflower nitrile, malononitrile, succinonitrile, glutaronitrile, adiponitrile, pimelonitrile, suberonitrile, azelaic acid dinitrile, sunflower nitrile, cyclopropylnitrile, cyclobutylnitrile, cyclopentylnitrile, cyclohexylnitrile, cycloheptylnitrile, tetracyanoethylene, acrylonitrile, isobutyronitrile, phthalonitrile, benzonitrile, benzyl cyanoacrylate, benzyl propionitrile, methyl 2-cyanoacrylate, ethyl 2-cyanoacrylate, propyl 2-cyanoacrylate, and butyl 2-cyanoacrylate; The organic solvent includes one or more of diphenyl ether, dimethyl sulfoxide, N,N-dimethylformamide, dimethylacetamide, N-methylpyrrolidone, hexamethylphosphorotriamide, and hexaethylphosphorotriamide.

6. A solid electrolyte membrane using the organic-inorganic composite solid electrolyte according to claim 1, characterized in that: The ratio of the number of charges transported by alkali metal cations in the composite solid electrolyte to the total number of charges transported by anions and cations is not less than 0.

9.

7. A method for preparing a solid electrolyte membrane of an organic-inorganic composite solid electrolyte according to claim 6, characterized in that: Prepare organic-inorganic composite solid electrolyte membrane by dry film formation or wet film formation; The dry film forming method comprises using a film press to press the prepared organic-inorganic composite solid electrolyte powder material at 45-300°C and 101.3kPa-20MPa to form an organic-inorganic composite solid electrolyte membrane; the thickness of the organic-inorganic composite solid electrolyte membrane is 1-500 μm, and the porosity is less than or equal to 20%; The wet membrane preparation method comprises adding the prepared organic-inorganic composite solid electrolyte powder material to a solvent, stirring at a speed of 100 to 3000 r / min and a temperature of 45°C to 300°C for 1 to 72 hours to prepare a slurry; applying the prepared slurry to a flat plate or film-like skeleton material by casting, casting, spin coating or coating, and drying the solvent at a temperature of 40 to 300°C to form a diaphragm, with the drying treatment time being 1 to 72 hours; the thickness of the organic-inorganic composite solid electrolyte membrane is 1 to 500 μm; The flat plate is a glass plate, a polytetrafluoroethylene plate or a stainless steel plate; The membranous skeleton material is a dense membrane or a porous membrane, the dense membrane is a composite membrane composed of one or more of Nafion membrane, perfluorosulfonic acid-polytetrafluoroethylene membrane, polytrifluorostyrene sulfonic acid membrane, polydifluorostyrene sulfonic acid membrane, polyaryletherketone sulfonic acid membrane, polyimide sulfonic acid membrane, and sulfonated polysulfone membrane; the porous membrane is a composite membrane composed of one or more of PP membrane, PE membrane, cellulose non-woven membrane, polyimide non-woven membrane, algae fiber non-woven membrane, aramid non-woven membrane, polyarylsulfoneamide non-woven membrane, polypropylene non-woven membrane, glass fiber membrane, and polyethylene terephthalate non-woven membrane; The solvent includes one or more of acetonitrile, cyclohexane, tetrahydrofuran, diphenyl ether, dimethyl sulfoxide, N,N-dimethylformamide, dimethylacetamide, N-methylpyrrolidone, hexamethylphosphorotriamide, and hexaethylphosphorotriamide.

8. Use of the organic-inorganic composite solid electrolyte membrane according to claim 6, characterized in that: Used to assemble a solid-state battery, the solid-state battery consisting of a positive electrode, an organic-inorganic composite solid electrolyte membrane and a negative electrode; The positive electrode is composed of a positive electrode active material or a positive electrode active material with a polymer surface layer, a conductive agent and a binder; The positive electrode active material is lithium ferrous phosphate, lithium manganese iron phosphate, lithium cobalt oxide, lithium manganese oxide, nickel cobalt manganese ternary material, lithium nickel manganese oxide, transition metal oxide A x MO2, wherein 1≤x≤2, A is one or two of Na or K, M is one or more of Co, Fe, Mn and Ni, polyanion compound A X M Y (X a O b )Z w , wherein 1≤X≤6, 1≤Y≤5, 1≤a≤8, 4≤b≤32, 0≤w≤3, A is one or more of Na or K, M is one or more of Ti, V, Cr, Mn, Fe, Co, Ni, Ca, Mg, Al, and Nb, X is one or more of Si, S, P, As, B, Mo, W, and Ge, and Z is one or more of F, O, and H, Prussian blue compound A x M1[M2(CN)6] 1-y , wherein 0<x<2, 0<y<1, A is Na or K, M1 and M2 are a composite positive electrode composed of one or more of Mn, Fe, Co, Ni, Cu, and Zn; The polymer surface layer on the surface of the positive electrode active material is a polymer containing C=N and / or CN groups formed by in-situ polymerization of an organic compound having a nitrogen-containing unsaturated bond; The preparation method of the positive electrode active material with a polymer surface layer comprises: adding a polymer precursor and a positive electrode active material to an organic solvent, stirring to prepare a mixture, catalyzing a polymerization reaction of the precursor with Lewis base oxygen atoms in the positive electrode active material to in situ generate a polymer containing C=N and / or CN groups, and drying the solvent to obtain the positive electrode active material with a polymer surface layer; the specific preparation method includes: The positive electrode active material includes lithium cobalt oxide, lithium manganese oxide, nickel cobalt manganese ternary material, lithium nickel manganese oxide and transition metal oxide A x MO2, wherein 1≤x≤2, A is one or two of Na or K, and M is one or more of one or more of Co, Fe, Mn, and Ni. The mixture is stirred at a speed of 100 to 3000 r / min and a temperature of 45° C. to 300° C. for 1 to 72 hours, and the precursor can undergo polymerization to form a polymer containing C=N and / or CN groups. The polymer precursor is an organic compound having a nitrogen-containing unsaturated bond, including one or more of propionitrile, butyronitrile, valeronitrile, capronitrile, heptanenitrile, octanonitrile, nonanenitrile, sunflower nitrile, malononitrile, succinonitrile, glutaronitrile, adiponitrile, pimelonitrile, suberonitrile, azelaic acid dinitrile, sunflower nitrile, cyclopropylnitrile, cyclobutylnitrile, cyclopentylnitrile, cyclohexylnitrile, cycloheptylnitrile, tetracyanoethylene, acrylonitrile, isobutyronitrile, phthalonitrile, benzonitrile, benzyl cyanoacrylate, benzyl propionitrile, methyl 2-cyanoacrylate, ethyl 2-cyanoacrylate, propyl 2-cyanoacrylate, and butyl 2-cyanoacrylate; The organic solvent includes one or more of diphenyl ether, dimethyl sulfoxide, N,N-dimethylformamide, dimethylacetamide, N-methylpyrrolidone, hexamethylphosphoramide, and hexaethylphosphoramide; the mass ratio of the positive electrode active material to the polymer precursor is 1:0.1-10; the mass ratio of the organic solvent to the polymer precursor is 5-50:1; the conductive agent is one or more of acetylene black, BLACK PEARLS 2000, Ketjen black, Super-P, carbon nanotubes, carbon nanofibers, activated carbon, and graphene; The binder is a compound composed of one or more of styrene-butadiene rubber, polytetrafluoroethylene, sodium carboxymethyl cellulose, polyolefin, polyvinylidene fluoride and its derivatives, and organic-inorganic composite electrolyte; The preparation method of the positive electrode plate is as follows: a positive electrode active material with a surface layer attached thereto and / or without a surface layer, a conductive agent, a binder and a solvent are mixed by stirring, grinding and / or ball milling to form a slurry, the slurry is coated on the surface of the current collector by casting, casting, spin coating or coating, and the positive electrode plate is obtained by drying; the solvent used includes one or more of deionized water, ethanol, acetone, acetonitrile, cyclohexane, tetrahydrofuran, diphenyl ether, dimethyl sulfoxide, N,N-dimethylformamide, dimethylacetamide, N-methylpyrrolidone, hexamethylphosphorotriamide, and hexaethylphosphorotriamide; The current collector is one of aluminum foil, carbon-coated aluminum foil, nickel foam, and titanium foil; The solid-state battery has a solid electrolyte interlayer or no interlayer between the positive electrode and the organic-inorganic composite solid electrolyte membrane; the solid electrolyte interlayer is one of an inorganic solid electrolyte, a polymer solid electrolyte, an inorganic solid electrolyte-polymer solid electrolyte composite solid electrolyte, and an alkali metal salt-polymer composite solid electrolyte; The inorganic solid electrolyte includes one or more of an inorganic oxide solid electrolyte, a sulfide inorganic solid electrolyte, a halide inorganic solid electrolyte, and a boride inorganic solid electrolyte; The inorganic oxide solid electrolyte comprises A x MO y , one or more of garnet-type inorganic solid electrolytes, perovskite-type inorganic solid electrolytes and antiperovskite-type inorganic solid electrolytes; The A x MO y Type inorganic solid electrolyte, 0.6≤x≤5, 1<y≤4, A is one or more of Li, Na or K, and M is one or more of Si, B, Ge, Zr, Al, Ga, Ti, P, S, As, Se, Nb, Sn, Sb, Te, Nd, Y, I, and La; The garnet-type inorganic solid electrolyte comprises A 7-m La3Zr 2-m M m O 12 、A 7-2n La3Zr 2-n N n O 12 and A 7- 3d D d La3Zr2O 12 , wherein 0≤m≤2, 0≤n≤2, 0≤d<7 / 3, A is one or more of Li, Na or K, M is one or two of Ta and Nb, N is one or two of W and Mo, and D is one or two of Ga and Al; The perovskite inorganic solid electrolyte is A 3x La 0.67-x TiO3, wherein 0.04<x<0.17, and A is one or more of Li, Na, or K; The antiperovskite inorganic solid electrolyte is A3OX, wherein A is one or more of Li, Na or K, and X is one or more of Cl, Br or I; The sulfide inorganic solid electrolyte includes β-A3PS4, A7P3S 11 、thio-LISICON-type A 10±1 MP2X 12 , Argyrodite-type A6PS5X', wherein A is one or more of Li, Na or K, M is one or more of Ge, Si, Sn, Al or P, X is one or more of S or Se, and X' is one or more of Cl, Br or I; The halide inorganic solid electrolyte is A3YX6, wherein A is one or more of Li, Na or K, and X is one or more of Cl, Br or I; The boride inorganic solid electrolyte includes ABH4, ABH4-AX, ACB 11 H 12 , AM(BH4)3Cl and A2B 12 H 12 , wherein A is one or more of Li, Na or K, X is one or more of Cl, Br or I, and M is one or more of La, Ce or Gd; The polymer includes one or more of polyolefin, polyvinylidene fluoride, poly(vinylidene fluoride-hexafluoropropylene), cellulose, epoxy resin, polyacrylonitrile, polymethyl ethylene carbonate, polyethylene carbonate, polyimide, polyphenylene olefin, polysulfone, polyaryletherketone, polyarylethersulfone, polybenzimidazole, and polybenzothiazole; Alkali metal salts include one or more of ATFSI, AFSI, ABOB, APF6, AClO4, AAsF6, ABF4, ACH3SO3, ACF3SO3, AC4BO8, and AC2BF2O4, wherein A is Li, Na, or K; The negative electrode is one or more of an alkali metal negative electrode or an alkali metal composite negative electrode; The alkali metal is one or more of Li, Na or K; The composite negative electrode is composed of an alkali metal and a conductive skeleton material; The conductive skeleton material is a three-dimensional self-supporting material or a composite skeleton material. The composite skeleton material is made of one or two of carbon-based materials or silicon-based materials, a conductive agent and a binder. The three-dimensional self-supporting material includes one or more of stainless steel mesh, copper mesh, nickel mesh, foam nickel, foam copper, carbon cloth, carbon fiber felt, carbon plate, graphene, and electrostatically spun organic polymer fiber cloth; The carbon-based material is one or more of graphite, amorphous carbon, mesocarbon microbeads, hard carbon, and soft carbon; The silicon-based material is one or more of silicon, tin-silicon alloy, aluminum-silicon alloy, titanium-silicon alloy, nickel-silicon alloy, tungsten-silicon alloy, iron-silicon alloy, copper-silicon alloy, manganese-silicon alloy, cobalt-silicon alloy, germanium-silicon alloy, zinc-silicon alloy, magnesium-silicon alloy, and gallium-silicon alloy; The binder is a compound composed of one or more of styrene-butadiene rubber, polytetrafluoroethylene, sodium carboxymethyl cellulose, polyolefin, polyvinylidene fluoride and its derivatives, and organic-inorganic composite electrolyte; The composite skeleton material is prepared by mixing a carbon-based material and / or a silicon-based material, a conductive agent, a binder, and a solvent by stirring, grinding, or ball milling to form a slurry, coating the slurry on the surface of a copper foil or titanium foil current collector by casting, casting, spin coating, or coating, and drying to obtain the composite skeleton material; the solvent used includes one or more of deionized water, ethanol, acetone, acetonitrile, cyclohexane, tetrahydrofuran, diphenyl ether, dimethyl sulfoxide, N,N-dimethylformamide, dimethylacetamide, N-methylpyrrolidone, hexamethylphosphoramide, and hexaethylphosphoramide; The composite negative electrode is prepared by introducing alkali metal into the conductive skeleton by electrochemical deposition of alkali metal, melt infiltration of alkali metal or pressure filling of alkali metal; The solid-state battery has a solid electrolyte interlayer or no interlayer between the alkali metal negative electrode or composite negative electrode and the organic-inorganic composite solid electrolyte membrane; the solid electrolyte interlayer is one of an inorganic solid electrolyte, a polymer solid electrolyte, an inorganic solid electrolyte-polymer composite solid electrolyte, and a lithium salt-polymer composite solid electrolyte; The solid-state battery is assembled from a negative electrode, an organic-inorganic composite solid electrolyte membrane and a positive electrode in a stacked or wound manner. The battery is a button battery, a square soft-pack battery, a square shell battery or a cylindrical battery.

9. The use according to claim 8, characterized in that: The mixture is stirred at a speed of 1200 to 1600 r / min and a temperature of 85 to 95° C. for 10 to 14 hours, and the precursor can undergo a polymerization reaction to generate a polymer containing C=N and / or CN groups.

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