In-situ polymerized organic-inorganic composite electrolyte and preparation and application thereof

Abstract

The invention relates to an organic-inorganic composite solid electrolyte and a preparation method thereof, and the organic-inorganic composite solid electrolyte with higher room-temperature ionic conductivity and wider electrochemical window is prepared by compounding an oxide solid electrolyte, an unsaturated polymer crosslinked on the surface of the oxide solid electrolyte in situ and a polar organic solvent. The room-temperature ionic conductivity of the prepared composite solid electrolyte can reach 0.1 mS / cm or above, the electrochemical window is larger than 4.5 V, the alkali metal cation transference number is larger than 0.9, in addition, the composite solid electrolyte is easy to form a film, and the prepared composite solid electrolyte film is thin in thickness. The electrolyte membrane is used for assembling a solid-state alkali metal battery, has good interface stability with a positive electrode and a negative electrode, can inhibit the growth of alkali metal dendritic crystals, and remarkably improves the battery performance.

Description

Technical Field

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

[0002] The increasing energy consumption has triggered widespread interest in energy storage. Lithium-ion batteries (LIBs) have been widely promoted in consumer electronics and transportation electrification due to their environmental friendliness, high energy density, and operating voltage. Organic liquid electrolytes often used in commercial lithium-ion batteries are volatile and flammable, which can cause safety issues such as leakage and fire. The lithium metal anode, known as the "holy grail", is highly reactive and can lead to dendrite growth and continuous side reactions. Solid-state electrolytes can replace flammable liquid electrolytes, thereby effectively improving safety. They are also suitable for use with lithium metal anodes and are highly anticipated.

[0003] Solid electrolytes can be divided into two categories: polymer solid electrolytes and inorganic solid electrolytes. It is difficult for a single solid electrolyte to meet the various requirements of lithium metal batteries, such as sufficient ionic conductivity (>10-4S cm-1), high operating voltage (up to 4-5V for Li / Li+), appropriate mechanical strength (>6GPa) and good interface contact. Polymer electrolytes have good elasticity and adaptability to volume changes and can be widely used in flexible batteries. However, such polymers tend to crystallize at ambient temperature and have limited ionic conductivity. The thermodynamic instability of the interface also limits their compatibility with high-voltage cathode materials, while poor mechanical properties cannot inhibit the growth of dendrites. Inorganic solid electrolytes have high ionic conductivity, a wide electrochemical window and high mechanical strength, but their brittleness leads to poor processing performance and high contact resistance due to the fragile nature of inorganic electrolytes. In recent years, researchers have been committed to compounding inorganic fillers into polymer solid electrolytes to form polymer / inorganic composite electrolytes to achieve the synergistic effect of different materials. Inorganic fillers not only increase the mechanical strength of the polymer matrix, but also act as plasticizers to prevent polymer crystallization and improve the ionic conductivity of the electrolyte.

[0004] For example, CN202311194380.2 discloses a preparation method of a poly(trimethylene carbonate)-based polyurethane / ceramic composite electrolyte. Under an inert gas atmosphere, trimethylene carbonate monomer and an initiator are added to solvent I and stirred evenly, then catalyst I is added, and the reaction is carried out at 25-110 °C for 2-12 h; a homopolymer hydroxyl poly(trimethylene carbonate) is prepared; the hydroxyl poly(trimethylene carbonate) is dissolved in solvent II, a lithium salt, a diisocyanate, and inorganic ceramic particles are added and stirred evenly, and after the inorganic ceramic particles are evenly dispersed, catalyst II is added and stirred evenly to obtain an electrolyte precursor solution; it is dried in a vacuum oven to obtain a poly(trimethylene carbonate)-based polyurethane / ceramic composite electrolyte. Here, an organic-inorganic composite electrolyte is prepared by a multi-step catalytic polymerization method. CN202311151352.2 discloses a composite solid electrolyte membrane, its preparation method and application. Among them, the continuous network structure filled with gelatin provides a stable skeleton for the SPE like steel bars, and PVN acts as a polymer electrolyte matrix as cement. The two form an extremely stable "reinforced concrete" structure of PVN-gelatin through hydrogen bond interaction, which can give full play to the high-strength characteristics of gelatin and simultaneously achieve an overall improvement in the electrochemical performance of the composite electrolyte membrane. In addition, a large number of C=O and C-O in PVN in the system coordinate with Li+ to promote the conduction of Li+, and it can be used as a solid electrolyte membrane material. Compared with the prior art, in the present invention, a uniform three-dimensional Li+ conductive network is formed by adding an appropriate amount of gelatin in the PVN matrix, and a new fast ion transport channel is constructed, thereby improving the ion transference number and ionic conductivity of the electrolyte. CN202311130617.0 discloses a preparation method of an ultra-thin continuous network structure composite electrolyte membrane. A core-shell structure is constructed by coaxial electrospinning, and inorganic fillers are concentrated on the surface of the electrospun fibers at a low filling amount to construct a 3D filler continuous ion migration network support skeleton, where the polymer is the core and the inorganic filler is the shell. Then, a polymer / lithium salt pre-solidified liquid cured in situ is poured into the support skeleton to prepare a solid composite electrolyte film, and the final thickness of the composite film is only 11-25 μm. In the present invention, a 3D continuous lithium ion transfer network is effectively prepared by the coaxial electrospinning process, and the preparation process is simple. The inorganic fillers are concentrated on the surface of the polymer fibers, reducing the crystallinity of the polymer. At the same time, the interaction between the continuous inorganic fillers, the lithium salt, and the polymer increases the lithium ion transport channel, thereby improving the ionic conductivity of the composite solid electrolyte, and the obtained polymer composite electrolyte membrane has a high lithium ion conductivity at room temperature. In the above patents, a composite solid electrolyte is prepared by using an inorganic solid electrolyte and an in-situ polymerized polymer electrolyte, which has good ionic conductivity and simultaneously optimizes the film-forming property and interfacial stability of the solid electrolyte. However, the dual-ion conduction characteristics of the polymer electrolyte containing alkali metal cation salts will cause concentration polarization of alkali metal cations inside the solid electrolyte, and finally alkali metal dendrites will be generated.In addition, catalysts and initiators are used in the in-situ polymerization process, which not only makes the process more complex, but also the residual initiators may cause additional side reactions inside the battery. Therefore, developing a new type of solid electrolyte to achieve in-situ cross-linking polymerization of polymers without adding initiators while obtaining the interface stability between the electrode and the solid electrolyte is of great significance for constructing high-performance solid-state batteries. Summary of the Invention

[0005] The purpose of the present invention is to develop an in-situ cross-linking polymerized organic-inorganic composite electrolyte and its preparation method to achieve high ionic conductivity, a wide electrochemical window, low interfacial impedance with the electrode, and effectively inhibit the growth of alkali metal dendrites of the composite electrolyte, and promote the industrialization of solid-state batteries.

[0006] The in-situ polymerized organic-inorganic composite electrolyte described above is composed of an inorganic oxide solid electrolyte that can conduct alkali metal cations, an unsaturated polymer formed by the reaction of a halogen-containing polymer that undergoes in-situ cross-linking on its surface, and a polar organic solvent; the mass ratio of the inorganic oxide solid electrolyte to the halogen-containing polymer is 1:0.1 - 15 (preferably 1:0.5 - 10, more preferably 1:1 - 5); the mass ratio of the polar organic solvent to the halogen-containing polymer is 5 - 50:1 (preferably 10 - 30:1, more preferably 15 - 25:1);

[0007] The oxygen atoms in the inorganic oxide solid electrolyte are Lewis bases, including xA2O·yMO n (A is one or more of Li, Na, or K; M is one or several of Si, B, Ge, Zr, Al, Ga, Ti, P, S, As, Se, Nb, Sn, Sb, Te, Nd, Y, I, La, 0.6 < x < 5, 1 < y < 4), the garnet-type inorganic solid electrolyte includes A 7-m La3Zr 2-m M m O 12 (A is one or more of Li, Na, or K; M = one or two of Ta, Nb; 0 ≤ m ≤ 2), A 7-2n La3Zr 2-n N n O 12 (A is one or more of Li, Na, or K; N = one or two of W, Mo; 0 ≤ n ≤ 2), A 7-3d D d La3Zr2O 12 (A is one or more of Li, Na, or K; D = one or two of Ga, Al; 0 ≤ d ≤ 7 / 3); the perovskite-type inorganic solid electrolyte A 3x La 0.67-xOne or more of TiO3 (0.04 < x < 0.17) (A is one or more of Li, Na or K) and anti - perovskite inorganic solid electrolyte A3OX (A is one or more of Li, Na or K; X = one or more of Cl, Br or I); the particle size of the oxide solid electrolyte is 1 nm to 100 μm; the room - temperature ionic conductivity is not less than 10 -4 mS / cm, and the oxide solid electrolytes are all single - ion conductor solid electrolytes, and the alkali - metal cation transference number, that is, the percentage of the charge transferred by the alkali - metal cations in the total charge, is 1;

[0008] The halogen - containing polymer is a polymer containing halogen atoms (including one or two of F and Cl), including one or more of polyvinylidene fluoride, poly(vinylidene fluoride - hexafluoropropylene), polyfluorinated ethylene - propylene, poly(tetrafluoroethylene - ethylene), polytrifluoroethylene, polyvinyl fluoride, poly(ethylene trifluoride), polyvinylidene chloride, poly(vinylidene chloride - hexachloropropylene), poly(chlorinated ethylene - propylene), poly(tetrachloroethylene - ethylene), polyvinyl chloride, etc., and the molecular weight of the polymer is 1000 to 10000000;

[0009] The polar organic solvents include one or more of acetonitrile, ethanol, tetrahydrofuran, diphenyl ether, dimethyl sulfoxide, N,N - dimethylformamide, dimethylacetamide, N - methylpyrrolidone, hexamethylphosphorous triamide, hexaethylphosphorous triamide, triethyl phosphate, trimethyl phosphate, propylene carbonate, fluorinated propylene carbonate.

[0010] The thickness of the organic - inorganic composite solid electrolyte membrane is 1 to 500 μm. When coated on a flat plate or a dense membrane, the measured thickness is the thickness of the organic - inorganic composite solid electrolyte;

[0011] The unsaturated polymer is formed by an in - situ reaction after the halogen - containing polymer contacts with the inorganic oxide solid electrolyte, and the reaction process is as follows:

[0012]

[0013] Where A and B can be H, halogen atoms (including one or two of F and Cl) respectively, and X is a halogen atom (including one or two of F and Cl);

[0014] D is a halogenated alkyl chain segment C y H z M (2y-z) , where M is one or two of F or Cl atoms, 0 ≤ y ≤ 3 (when y = 0, the polymer chain has only - CAX - CHB - as the repeating unit), 0 ≤ z ≤ 2y, and both y and z are integers;

[0015] The organic-inorganic composite solid electrolyte membrane is attached to a membrane-like framework material; the membrane-like framework material can be a dense membrane or a porous membrane. The dense membrane can be a composite membrane composed of one or more of Nafion membranes, perfluorosulfonic acid-polytetrafluoroethylene membranes, polytrifluorostyrenesulfonic acid membranes, polydifluorostyrenesulfonic acid membranes, polyaryletherketone sulfonic acid membranes, polyimide sulfonic acid membranes, and sulfonated polysulfone membranes; the porous membrane can be a composite membrane composed of one or more of PP membranes, PE membranes, cellulose non-woven membranes, polyimide non-woven membranes, seaweed fiber non-woven membranes, aramid non-woven membranes, polyarylsulfonamide non-woven membranes, polypropylene non-woven membranes, glass fiber membranes, and polyethylene terephthalate non-woven membranes.

[0016] The preparation method of the in-situ polymerized organic-inorganic composite electrolyte is characterized in that: on the surface of the oxide solid electrolyte, an unsaturated polymer is in-situ polymerized and crosslinked; a halogen-containing polymer is mixed with an inorganic oxide solid electrolyte powder material, and at a certain temperature, the oxygen atoms on the surface of the inorganic oxide solid electrolyte that are Lewis bases induce the halogen-containing polymer to remove halogen elements, and an unsaturated polymer containing C═C groups is in-situ generated;

[0017] The specific reaction process is as follows:

[0018]

[0019] where B is a group that is a Lewis base on the surface of the inorganic oxide solid electrolyte;

[0020] The specific preparation process includes the following steps:

[0021] (1) The inorganic oxide solid electrolyte powder material, the halogen-containing polymer, and a polar organic solvent are stirred at a speed of 100-3000 r / min at room temperature for 1-72 h to be fully mixed to obtain a suspension. The speed is preferably 1200-1600 r / min, and the time is preferably 8-16 h;

[0022] (2) The slurry prepared in step (1) is coated onto a flat plate or a membrane-like framework material by a casting method, a casting method, a spin coating method, or a coating method, and is in-situ crosslinked and polymerized in a closed container at a temperature of 40-300 °C to form a separator, and the treatment time is 1-72 h.

[0023] For the solid electrolyte membrane of the in-situ polymerized organic-inorganic composite electrolyte, the alkali metal cation transference number is not less than 0.9.

[0024] The application of the in-situ polymerized organic-inorganic composite electrolyte is used as a separator for assembling a solid-state battery.

[0025] The solid-state battery is composed of a positive electrode, an in-situ polymerized organic-inorganic composite electrolyte membrane, and a negative electrode;

[0026] The positive electrode described above is composed of a positive electrode active material or a positive electrode active material with a polymer surface layer on its surface, a conductive agent, and a binder;

[0027] The positive electrode active material is lithium iron phosphate, lithium manganese iron phosphate, lithium cobaltate, lithium manganate, nickel cobalt manganese ternary material, lithium nickel manganate, transition metal oxide A x MO2 (A is Na or K, and M is one or more of Co, Fe, Mn, and Ni, etc.), polyanion compound A X M Y (X a O b )Z w (A is Na or K, M is one or more of Ti, V, Cr, Mn, Fe, Co, Ni, Ca, Mg, Al, Nb, etc., X is Si, S, P, As, B, Mo, W, Ge, etc., and Z is F, O, H, etc.), Prussian blue compound A x M1[M2(CN)6] 1-y (A is Na or K, and M1 and M2 are Mn, Fe, Co, Ni, Cu, Zn, etc.) and is a composite positive electrode composed of one or more of them;

[0028] The polymer surface layer on the surface of the positive electrode active material is an in-situ crosslinked unsaturated polymer;

[0029] The preparation method of the polymer surface layer on the surface of the positive electrode active material is as follows: adding a halogen-containing polymer and a positive electrode active material containing a Lewis base oxygen atom to a solvent, stirring to obtain a mixture, and under certain conditions, the Lewis base oxygen atom in the positive electrode active material induces the precursor to undergo a polymerization reaction to in-situ crosslink and generate a polymer coating layer, and drying the solvent to obtain a positive electrode material powder with a surface layer; the specific preparation methods include:

[0030] The positive electrode active material containing a Lewis base oxygen atom includes one or more of lithium cobaltate, lithium manganate, nickel cobalt manganese ternary material, lithium nickel manganate, transition metal oxide A x MO2 (A is Na or K, and M is one or more of Co, Fe, Mn, and Ni, etc.), stirring the mixture at a rotation speed of 100 - 3000 r / min and at a temperature of 45°C - 300°C for 1 - 72 h, wherein the rotation speed is preferably 1200 - 1600 r / min, the temperature is preferably 85 - 95°C, and the time is preferably 10 - 14 h to generate an in-situ crosslinked polymer layer;

[0031] The conductive agent is one or more of acetylene black, BLACK PEARLS2000, Ketjenblack, Super-P, carbon nanotubes, carbon nanofibers, activated carbon, and graphene;

[0032] The binder described above is a composite composed of one or more of styrene-butadiene rubber, polytetrafluoroethylene, sodium carboxymethyl cellulose, polyolefin, polyvinylidene fluoride and its derivatives, and organic-inorganic composite electrolyte;

[0033] The preparation method of the positive electrode plate is as follows: The positive electrode active material with or without a surface layer, a conductive agent, a binder and a solvent are mixed into a slurry by stirring, grinding or ball milling, and the slurry is coated on the surface of the current collector by casting method, doctor blade method, spin coating method or coating method, and then dried to obtain the positive electrode plate; The solvents used include one or more of deionized water, ethanol, acetone, acetonitrile, cyclohexane, tetrahydrofuran, diphenyl ether, dimethyl sulfoxide, N,N-dimethylformamide, dimethylacetamide, N-methylpyrrolidone, hexamethylphosphorous triamide, and hexaethylphosphorous triamide;

[0034] The current collector is one of aluminum foil, carbon-coated aluminum foil, nickel foam or titanium foil;

[0035] There is a solid electrolyte interlayer or no interlayer between the positive electrode of the solid-state battery and the organic-inorganic composite solid electrolyte membrane;

[0036] The solid electrolyte interlayer between the positive electrode and the in-situ polymerized 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, a lithium salt-polymer composite solid electrolyte; The inorganic solid electrolyte includes inorganic oxide solid electrolytes, including xA2O·yMO n (A is Li, Na or K; M is one or more of Si, B, Ge, Zr, Al, Ga, Ti, P, S, As, Se, Nb, Sn, Sb, Te, Nd, Y, I, La, 0.6 < x < 5, 1 < y < 4), garnet-type inorganic solid electrolytes include A 7-m La3Zr 2-m M m O 12 (A is Li, Na or K; M = Ta, Nb; 0 ≤ m ≤ 2), A 7-2n La3Zr 2-n N n O 12 (A is Li, Na or K; N = W, Mo; 0 ≤ n ≤ 2), A 7-3d D d La3Zr2O 12 (A is Li, Na or K; D = Ga, Al; 0 ≤ d ≤ 7 / 3); perovskite-type inorganic solid electrolyte A 3x La 0.67-xTiO3(0.04 < x < 0.17) (A is Li, Na or K) and anti - perovskite inorganic solid electrolytes A3OX (A is Li, Na or K; X = Cl, Br or I), β - A3PS4 (A is Li, Na or K), A7P3S 11 (A is Li, Na or K), thio - LISICON - type A 10±1 MP2X 12 (A is Li, Na or K; M = Ge, Si, Sn, Al or P; X = S or Se), Argyrodite - type A6PS5X (A is Li, Na or K; X = Cl, Br or I), A3YX6 (A is Li, Na or K; X = Cl, Br or I), ABH4 (A is Li, Na or K), ABH4 - AX (A is Li, Na or K; X = Cl, Br or I), ACB 11 H 12 (A is Li, Na or K), AM(BH4)3Cl (A is Li, Na or K; M = one or more of La, Ce or Gd) and A2B 12 H 12 (A is Li, Na or K); one or more of the following;

[0037] The polymers include one or more of polyolefins, polyvinylidene fluoride, poly(vinylidene fluoride - hexafluoropropylene), cellulose, epoxy resins, polyacrylonitrile, poly(methyl ethylene carbonate), poly(ethylene carbonate), polyimides, polystyrenes, polysulfones, poly(aryl ether ketones), poly(aryl ether sulfones), polybenzimidazoles, and polybenzothiazoles;

[0038] The 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);

[0039] The negative electrode is one of an alkali metal negative electrode or an alkali metal composite negative electrode;

[0040] The alkali metal is Li, Na or K;

[0041] The composite negative electrode is composed of an alkali metal and a conductive skeleton material;

[0042] The conductive skeleton materials are 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,

[0043] The three - dimensional self - supporting materials include one or more of stainless steel mesh, copper mesh, nickel mesh, nickel foam, copper foam, carbon cloth, carbon fiber felt, carbon plate, graphene, and electrospun organic polymer fiber cloth;

[0044] The carbon-based material is one or more of graphite, amorphous carbon, mesophase carbon microspheres, hard carbon, and soft carbon;

[0045] 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;

[0046] The binder is a composite composed of one or several of styrene-butadiene rubber, polytetrafluoroethylene, sodium carboxymethyl cellulose, polyolefin, polyvinylidene fluoride and its derivatives, and organic-inorganic composite electrolyte;

[0047] The preparation method of the composite skeleton material is as follows: mixing the carbon-based material or silicon-based material, conductive agent, binder and solvent by stirring, grinding or ball milling to form a slurry, and coating the slurry on the surface of a copper foil or titanium foil current collector by casting method, doctor blade method, spin coating method or coating method, and drying to obtain a negative electrode sheet; the solvents used include one or several of deionized water, ethanol, acetone, acetonitrile, cyclohexane, tetrahydrofuran, diphenyl ether, dimethyl sulfoxide, N,N-dimethylformamide, dimethylacetamide, N-methylpyrrolidone, hexamethylphosphorous triamide, and hexaethylphosphorous triamide;

[0048] The composite negative electrode is prepared by introducing an alkali metal into the conductive skeleton by means of electrochemical deposition of an alkali metal, molten infiltration of an alkali metal or pressure filling of an alkali metal;

[0049] There is or is no solid electrolyte interlayer between the alkali metal negative electrode or composite negative electrode of the solid-state battery and the in-situ polymerized 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;

[0050] The solid-state battery is assembled into a solid-state battery by laminating or winding the negative electrode, the organic-inorganic composite solid electrolyte separator and the positive electrode. The battery can be a button battery, a square soft-pack battery, a square shell battery or a cylindrical battery.

[0051] The room-temperature ionic conductivity of the composite solid electrolyte prepared by the present invention can reach above 0.1 mS / cm, the electrochemical window is greater than 4.5 V, and the transference number of alkali metal cations is greater than 0.9. In addition, the composite solid electrolyte is easy to form a film, and the obtained composite solid electrolyte film is thin. Using this electrolyte film to assemble a solid-state alkali metal battery has good interfacial stability with the positive and negative electrodes, can inhibit the growth of alkali metal dendrites, and significantly improve the battery performance.

[0052] The advantages of the present invention are as follows:

[0053] 1. The oxygen atoms on the surface of the inorganic oxide solid electrolyte capable of conducting alkali metal cations used in the present invention are Lewis bases. The strong electronegativity of the halogen atoms on the halogen-containing polymer chain segments enhances the acidity of the hydrogen atoms on the surrounding carbon atoms, showing Lewis basicity. The oxygen atoms can induce the β-elimination reaction of the halogenated polymer at a certain temperature, that is, the surface oxygen atoms attack the hydrogen atoms on the adjacent carbon atoms of the carbon atom connected to the halogen atoms, causing the halogenated polymer to eliminate a molecule of hydrogen halide, and obtaining an unsaturated polymer containing C═C. Further cross-linking polymerization reaction occurs at a certain temperature to form close contact with the inorganic oxide solid electrolyte. At the same time, the halogen atoms have a high electron cloud density, attracting the alkali metal cations of the inorganic oxide solid electrolyte to accumulate on the surface, forming a space charge layer more conducive to the transport of alkali metal cations at the interface between the organic phase and the inorganic solid electrolyte, becoming the main conduction path of alkali metal cations in the in-situ cross-linked polymerized organic-inorganic composite electrolyte, and significantly improving the room-temperature ionic conductivity of the in-situ cross-linked polymerized organic-inorganic composite electrolyte; in addition, by using the reaction of the halogen-containing polymer with the Lewis basic oxygen atoms on the surface of the positive electrode, a surface layer can be formed on the surface of the positive electrode material to improve the battery performance;

[0054] 2. The inorganic oxide solid electrolyte with single-ion conduction characteristics used in the present invention is combined with a polymer to prepare an in-situ polymerized organic-inorganic composite electrolyte. Since no alkali metal cation salt is added, the in-situ cross-linked polymerized composite solid electrolyte is a single-ion conductor, having the advantage of high ion transference number, and can inhibit the growth of alkali metal dendrites; due to the inclusion of the inorganic oxide solid electrolyte, the electrochemical window of the in-situ polymerized composite solid electrolyte is significantly improved compared with the polymer electrolyte, having good application prospects.

[0055] 3. The in-situ polymerized organic-inorganic composite solid electrolyte prepared by the present invention disperses the oxide solid electrolyte evenly 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 large-area thin films, effectively reducing the impedance of the film. At the same time, due to the flexibility of the organic-inorganic composite solid electrolyte prepared by in-situ crosslinking polymerization, good interfacial contact is formed with the positive and negative electrodes. These advantages enable the organic-inorganic composite solid electrolyte membrane to have fast alkali metal ion conduction performance, good interfacial stability with the positive and negative electrodes, dendrite growth inhibition ability, and oxidation resistance stability, which can significantly improve the safety performance and cycle life of the battery.

[0056] 4. The present invention uses this composite solid electrolyte of single-ion conductor in-situ polymerization to prepare a solid-state battery. The preparation method is compatible with the equipment and processes of existing lithium-ion batteries, and almost all types of batteries can be prepared through various assembly methods including stacking and winding, including: button batteries, soft-pack batteries, square-shell batteries, and cylindrical batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 SEM image of LAGP after being compounded with polyvinylidene fluoride in Comparative Example 1. It can be seen from the figure that LAGP after being compounded with polyvinylidene fluoride cannot be evenly dispersed in the composite electrolyte, and cracks are observed on the surface. This is because the oxygen atoms of the LAGP oxide solid electrolyte are present in the phosphate groups and do not contain oxygen atoms that are Lewis bases. Polyvinylidene fluoride cannot undergo an in-situ polymerization reaction on the surface of LAGP to achieve a tight combination of LAGP and polyvinylidene fluoride.

[0058] Figure 2 TEM image of LLZTO after being compounded with polyperfluoroethylene in Comparative Example 2. It can be seen from the figure that no amorphous layered structure can be observed on the surface of LLZTO after being compounded with polyperfluoroethylene. This shows that since polyperfluoroethylene does not contain hydrogen atoms that provide acidity, it cannot react with the oxygen atoms that are Lewis bases on the surface of the oxide solid electrolyte LLZTO, and no polymer surface layer is formed on the surface of LLZTO.

[0059] Figure 3 SEM image of the composite electrolyte PVDF-LLZTO after reacting with the polymer precursor polyvinylidene fluoride in Example 1;

[0060] Figure 4TEM image of the composite electrolyte PVDF-LLZTO after reacting with the polymer precursor polyvinylidene fluoride in Example 1. As can be seen from the figure, the LLZTO particles after reacting with polyvinylidene fluoride are evenly dispersed in the composite electrolyte, and at the same time, they have a uniform amorphous surface layer. This indicates that under the induction of LLZTO, polyvinylidene fluoride generates an in-situ crosslinked surface layer on the surface of LLZTO, changing the surface structure of LLZTO.

[0061] Figure 5 Raman comparison chart of the composite electrolyte PVDF-LLZTO after reacting with the polymer precursor polyvinylidene fluoride in Example 1 and the composite electrolyte obtained by compounding LAGP and polyvinylidene fluoride in Comparative Example 1. Compared with the PVDF-LAGP sample, the peak of the C═C bond is observed in PVDF-LLZTO, which indicates that under the induction of LLZTO, polyvinylidene fluoride undergoes a defluorination reaction on the surface of LLZTO and further crosslinks.

[0062] Figure 6 Polarization voltage-time curve graph of the Li-Li symmetric batteries assembled with the polyhexafluoroethylene-LLZTO composite solid electrolyte membrane in Comparative Example 2 and the PVDF-LLZTO composite electrolyte in Example 1 respectively. From the figure, the composite electrolyte membrane prepared by compounding LLZTO and PVDF significantly improves the cycling stability of the lithium anode, and the cycle life > 2000 h.

[0063] Figure 7 Cycle-specific capacity comparison curve graph of the batteries assembled with the PVDF-LAGP composite solid electrolyte membrane in Comparative Example 1 and PVDF-LLZTO in Example 1. From the figure, the PVDF-LLZTO composite electrolyte membrane improves the specific capacity and cycling stability of the LFP / Li lithium battery (150 mAh / g; the capacity retention rate after 450 cycles is ~90%) Example

[0064] The following is a detailed description of the specific embodiments of the present invention. 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.

[0065] Comparative Example 1:

[0066] In this comparative example, 0.6 g of polyvinylidene fluoride and 1.2 g of lithium germanium phosphate aluminum (LAGP) powder were added to 10 g of acetonitrile, and the mixture was stirred evenly at a rotation speed of 100 r / min at room temperature for 4 h to obtain a suspension, thereby preparing an organic-inorganic composite solid electrolyte slurry. The slurry was coated on a cellulose membrane using a coating method and then subjected to crosslinking polymerization in a sealed container at a certain temperature under the conditions of 100 °C for 24 h to obtain an organic-inorganic composite solid electrolyte membrane, which was cut into circular pieces with a diameter of 19 mm for standby. The thickness of the composite solid electrolyte membrane was 40 μm. Through electrochemical testing, the room-temperature ionic conductivity of the composite solid electrolyte was 0.01 mS / cm, the electrochemical window was 4.0 V, and the lithium-ion transference number was 0.75. The preparation method of the positive electrode plate was as follows: 80 mg of LFP positive electrode powder, 9 mg of PVDF binder, 1 mg of polyvinylidene fluoride-LAGP composite solid electrolyte slurry, and 10 mg of Super P conductive agent were evenly dispersed in 100 mg of NMP solvent, ground in a mortar for 1 h, coated on aluminum foil, and vacuum dried at 100 °C for 24 h to obtain an LFP positive electrode plate, which was cut into circular pieces with a diameter of 10 mm for standby. The preparation method of the solid electrolyte coating layer on the surface of the positive electrode was as follows: 1 g of polyvinylidene fluoride-LAGP composite solid electrolyte was evenly dispersed in 9 g of NMP solvent, and the mixture was stirred evenly at a rotation speed of 1500 r / min at 45 °C for 12 h to obtain a uniform slurry. The prepared slurry was coated on the positive electrode using a coating method and then dried. The drying conditions were vacuum drying at 100 °C for 24 h. Finally, a 2016-type button battery was assembled with the LFP coated with solid electrolyte as the positive electrode, metallic lithium as the negative electrode, and the solid electrolyte composite membrane as the electrolyte, and the cycle performance rapidly decayed at a 1C rate.

[0067] Comparative Example 2:

[0068] In this comparative example, 0.6 g of polyperfluoroethylene and 1.2 g of LLZTO powder were added to 10 g of ethanol, and the mixture was magnetically stirred at a speed of 1500 r / min for 1 h at room temperature to obtain an organic-inorganic composite solid electrolyte slurry. The slurry was coated on a cellulose membrane using a coating method and then crosslinked and polymerized at a certain temperature. The conditions were to keep it in a sealed container at 100 °C for 24 h, and then an organic-inorganic composite solid electrolyte membrane was obtained. It was cut into circular pieces with a diameter of 19 mm for standby. The thickness of the composite solid electrolyte membrane was 40 μm. Electrochemical tests showed that the room-temperature ionic conductivity of the composite solid electrolyte was 0.01 mS / cm, which was much lower than that of the composite solid electrolyte in the example, which could reach 0.1 mS / cm. The electrochemical window was 4.0 V, which was much lower than that of the composite solid electrolyte in the example. The lithium-ion transference number was 0.75, which was much lower than that of the composite solid electrolyte in the example. The preparation method of the positive electrode sheet was as follows: 80 mg of LFP positive electrode powder, 9 mg of PVDF binder, 1 mg of polyperfluoroethylene-LLZTO composite solid electrolyte slurry, and 10 mg of Super P conductive agent were uniformly dispersed in 100 mg of NMP solvent. After grinding in a mortar for 1 h, it was coated on an aluminum foil and vacuum dried at 100 °C for 24 h to obtain an LFP positive electrode sheet, which was cut into circular pieces with a diameter of 10 mm for standby. The preparation method of the solid electrolyte coating layer on the positive electrode surface was as follows: 1 g of polyperfluoroethylene-LLZTO composite solid electrolyte was uniformly dispersed in 9 g of NMP solvent, and stirred at a speed of 1500 r / min at 45 °C for 12 h to obtain a uniform slurry. The prepared slurry was coated on the positive electrode using a coating method and then dried. The drying conditions were vacuum drying at 100 °C for 24 h. Finally, a 2016-type button battery was assembled with the LFP coated with solid electrolyte as the positive electrode, metallic lithium as the negative electrode, and the solid electrolyte composite membrane as the electrolyte. The capacity retention rate was less than 80% after cycling 53 times at a 1C rate.

[0069] Comparative Example 3:

[0070] In this example, 0.5 g of polyfluorinated ethylene propylene and 1 g of lithium nitride powder were added to 10 g of dimethyl sulfoxide, and stirred at a speed of 1500 r / min for 12 h at room temperature to prepare an organic-inorganic composite solid electrolyte slurry. The slurry was cast on a polyimide non-woven film using the casting method and then crosslinked and polymerized at a certain temperature. The conditions were to keep it in a sealed container at 300 °C for 1 h, and then an organic-inorganic composite solid electrolyte membrane was obtained. The thickness of the composite solid electrolyte membrane was 100 μm, and it was cut into circular pieces with a diameter of 19 mm for standby. Electrochemical tests showed that the room-temperature ionic conductivity of the composite solid electrolyte was 0.12 mS / cm, the electrochemical window reached 4.6 V, and the lithium ion transference number was 0.9. The preparation method of the positive electrode sheet was as follows: 80 mg of lithium nickel manganate positive electrode powder, 10 mg of PVDF binder, and 10 mg of Ketjenblack conductive agent were uniformly dispersed in NMP solvent, ground in a mortar for 1 h, then coated on aluminum foil and vacuum dried at 100 °C for 24 h to obtain a lithium nickel manganate positive electrode sheet, which was cut into circular pieces with a diameter of 10 mm for standby. The preparation method of the solid electrolyte coating layer on the surface of the positive electrode was as follows: 1 g of polybenzimidazole-lithium nitride composite solid electrolyte powder was uniformly dispersed in 4 g of N-methylpyrrolidone solvent, and stirred at a speed of 3000 r / min at 300 °C for 1 h to prepare a uniform slurry, which was coated on the positive electrode and then dried. The drying conditions were vacuum drying at 100 °C for 24 h. Finally, a 2016-type button battery was assembled with lithium nickel manganate coated with solid electrolyte as the positive electrode, metallic lithium as the negative electrode, and the solid electrolyte composite membrane as the electrolyte. The capacity retention rate was less than 50% after 100 cycles at a 1C rate.

[0071] Comparative Example 4:

[0072] In this example, 2 g of poly(tetrafluoroethylene-ethylene), 1 g of LATP powder were added to 10 g of N,N-dimethylformamide, and magnetically stirred at a speed of 1500 r / min for 5 h at room temperature to prepare an organic-inorganic composite solid electrolyte slurry. The slurry was coated on an aramid nonwoven membrane by the casting method and kept in a sealed container at 40 °C for 72 h to obtain an organic-inorganic composite solid electrolyte membrane. The thickness of the composite solid electrolyte membrane was 200 μm, and it was cut into circular pieces with a diameter of 19 mm for standby. 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 transference number was 0.91. The preparation method of the positive electrode sheet was as follows: 80 mg of lithium cobaltate positive electrode powder, 8 mg of PVDF binder, 2 mg of poly(tetrafluoroethylene-ethylene)-LATP 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 h, then coated on nickel foam, and vacuum dried at 100 °C for 24 h to obtain a lithium cobaltate positive electrode sheet. The preparation method of the solid electrolyte coating layer on the positive electrode surface was as follows: 1 g of polybenzothiazole-LATP composite solid electrolyte powder was uniformly dispersed in 9 g of NMP solvent, stirred at a speed of 100 r / min and at a temperature of 45 °C for 72 h to obtain a uniform slurry, and then coated on the positive electrode and dried. The drying conditions were vacuum at 100 °C for 24 h. The preparation method of the negative electrode sheet was as follows: 80 mg of graphite powder, 10 mg of PVDF binder and 10 mg of BLACK PEARLS 2000 conductive agent were uniformly dispersed in NMP solvent, ground in a mortar for 1 h, then coated on nickel foam and vacuum dried at 100 °C for 24 h, and then cut into circular pieces with a diameter of 10 mm for standby. Then, a composite negative electrode was prepared by the melting method: metallic lithium was heated to 180 °C to melt, and the negative electrode sheet was immersed in the molten metallic lithium and cooled to room temperature. Finally, a soft-pack battery was assembled with lithium cobaltate coated with solid electrolyte as the positive electrode, graphite as the negative electrode, and the solid electrolyte composite membrane as the electrolyte, and it could not be effectively cycled at a 1C rate.

[0073] Comparative Example 5:

[0074] In this example, 3 g of polytetrafluoroethylene and 0.2 g of lithium indium chloride (Li3InCl6) powder were added to 10 g of dimethylacetamide, and the mixture was stirred evenly at a speed of 1600 r / min at room temperature for 4 h to obtain an organic-inorganic composite solid electrolyte slurry. The slurry was coated on a polypropylene non-woven membrane by spin coating at a speed of 600 rpm / s and kept in a sealed container at 120 °C for 18 h to obtain an organic-inorganic composite solid electrolyte membrane with a thickness of 50 μm. The membrane was cut into circular pieces with a diameter of 19 mm for standby. Electrochemical tests 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. The preparation method of the positive electrode sheet was as follows: 80 mg of NCM622 positive electrode powder, 7 mg of PVDF binder, 3 mg of polytetrafluoroethylene-Li3InCl6 composite solid electrolyte powder, and 10 mg of acetylene black conductive agent were evenly dispersed in NMP solvent. After grinding in a mortar for 1 h, the mixture was coated on a carbon-coated aluminum foil and vacuum dried at 120 °C for 24 h to obtain an NCM622 positive electrode sheet, which was cut into circular pieces with a diameter of 10 mm for standby. The preparation method of the solid electrolyte coating layer on the positive electrode surface was as follows: an LLZO coating with a thickness of 200 nm was prepared on the positive electrode sheet by magnetron sputtering. The preparation method of the negative electrode sheet was as follows: 80 mg of hard carbon powder, 10 mg of PVDF binder, and 10 mg of acetylene black conductive agent were evenly dispersed in NMP solvent. After grinding in a mortar for 1 h, the mixture was coated on a copper foil and vacuum dried at 120 °C for 24 h to obtain a hard carbon negative electrode sheet, which was cut into circular pieces with a diameter of 10 mm for standby. Then, a lithium-containing composite negative electrode was prepared by an electrochemical method. The composite negative electrode was obtained by discharging at a current density of 0.1 mA cm -2 to 0.001 V by a constant current method. Finally, a 2016-type button battery was assembled with the NCM622 positive electrode with a solid electrolyte coating layer, the hard carbon negative electrode, and the solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 94% after 300 cycles at a 1C rate.

[0075] Example 1:

[0076] In this example, 0.5 g of polyvinylidene fluoride and 1 g of lithium lanthanum zirconium tantalum oxide (LLZTO) powder were added to 10 g of tetrahydrofuran, and the mixture was stirred at a speed of 100 r / min for 72 h at room temperature to obtain an organic-inorganic composite solid electrolyte slurry. The slurry was coated on a cellulose membrane using a coating method and then crosslinked and polymerized at a certain temperature. The conditions were to maintain it in a sealed container at 100 °C for 24 h, and then an organic-inorganic composite solid electrolyte membrane was obtained. It was cut into circular pieces with a diameter of 19 mm for standby. The thickness of the composite solid electrolyte membrane was 40 μm. Electrochemical tests showed that the room-temperature ionic conductivity of the composite solid electrolyte was 0.11 mS / cm, the electrochemical window reached 4.9 V, and the lithium-ion transference number was 0.92. A composite membrane prepared from LLZTO powder not compounded with polyvinylidene fluoride and a cellulose membrane was used as a control group. The preparation method of the positive electrode plate was as follows: 80 mg of LFP positive electrode powder, 9 mg of PVDF binder, 1 mg of polyvinylidene fluoride-LLZTO composite solid electrolyte slurry, and 10 mg of Super P conductive agent were uniformly dispersed in 100 mg of NMP solvent. After grinding in a mortar for 1 h, it was coated on aluminum foil and vacuum dried at 100 °C for 24 h to obtain an LFP positive electrode plate, which was cut into circular pieces with a diameter of 10 mm for standby. The preparation method of the solid electrolyte coating layer on the surface of the positive electrode was as follows: 1 g of polyvinylidene fluoride-LLZTO composite solid electrolyte was uniformly dispersed in 9 g of NMP solvent, and the mixture was stirred at a speed of 1500 r / min at 45 °C for 12 h to obtain a uniform slurry. The prepared slurry was coated on the positive electrode using a coating method and then dried. The drying conditions were vacuum drying at 100 °C for 24 h. Finally, a 2016-type button battery was assembled with the LFP coated with solid electrolyte as the positive electrode, metallic lithium as the negative electrode, and the solid electrolyte composite membrane as the electrolyte. The capacity retention rate was ~90% after 450 cycles at a 1C rate.

[0077] Example 2:

[0078] In this example, 0.1 g of poly(vinylidene fluoride - hexafluoropropylene), 1 g of lithium lanthanum titanium oxide (LLTO) powder were mixed in 5 g of diphenyl ether, and stirred evenly at a speed of 3000 r / min at room temperature for 1 h to prepare an organic - inorganic composite solid electrolyte slurry. The slurry was coated on a cellulose membrane using a coating method and crosslinked and polymerized at a certain temperature. The conditions were to maintain it in a sealed container at 100 °C for 24 h, and then an organic - inorganic composite solid electrolyte membrane was obtained. It was cut into circular pieces with a diameter of 19 mm for standby. The thickness of the composite solid electrolyte membrane was 40 μm. 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 lithium - ion transference number was 0.9. The solid electrolyte membrane prepared from LLTO powder not compounded with poly(vinylidene fluoride - hexafluoropropylene) was used as a control group. The preparation method of the positive electrode sheet was as follows: 210 mg of NCM622 positive electrode powder with a surface layer having a precursor of poly(vinylidene fluoride - hexafluoropropylene), 2.5 mg of PVDF binder, 25 mg of poly(vinylidene fluoride - hexafluoropropylene) - LLTO composite solid electrolyte slurry, and 25 mg of carbon nanofiber conductive agent were uniformly dispersed in NMP solvent, magnetically stirred for 4 h, then coated on aluminum foil and vacuum - dried at 120 °C for 24 h to obtain an NCM622 positive electrode sheet, which was cut into circular pieces with a diameter of 10 mm for standby. The preparation method of the polymer surface layer on the surface of the positive electrode active material was as follows: 0.5 g of poly(vinylidene fluoride - hexafluoropropylene) and 0.5 g of NCM622 powder were mixed in 2 g of NMP, and magnetically stirred at a speed of 1500 r / min at room temperature for 4 h to obtain a suspension. Then the obtained suspension was stirred evenly at a speed of 3000 r / min at 45 °C for 72 h to polymerize poly(vinylidene fluoride - hexafluoropropylene) on the surface of NCM622 powder, and an NCM622 suspension containing a surface layer was prepared. The suspension was placed in a vacuum oven at 40 °C and dried for 72 h to obtain an NCM622 powder material with a surface layer having a precursor of poly(vinylidene fluoride - hexafluoropropylene). The preparation method of the solid electrolyte coating layer on the positive electrode surface was as follows: 1 g of polyvinylidene fluoride - LiFSI - LLTO composite solid electrolyte was uniformly dispersed in 9 g of NMP solvent, and stirred at a speed of 1500 r / min at 45 °C for 12 h to obtain a uniform slurry. The prepared slurry was coated on the positive electrode and then dried. The drying conditions were vacuum - drying at 100 °C for 24 h. Finally, a 2032 - type button battery was assembled with NCM622 coated with solid electrolyte 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.

[0079] Example 3:

[0080] In this example, 0.5 g of polyfluorinated ethylene propylene and 1 g of lithium lanthanum zirconium oxide (LLZO) powder were added to 10 g of dimethyl sulfoxide, and the mixture was stirred at a speed of 1500 r / min for 12 h at room temperature to obtain an organic-inorganic composite solid electrolyte slurry. The slurry was cast onto a polyimide non-woven membrane using the casting method and then cross-linked and polymerized at a certain temperature. The conditions were to maintain it in a sealed container at 300 °C for 1 h, and then an organic-inorganic composite solid electrolyte membrane was obtained. The thickness of the composite solid electrolyte membrane was 100 μm, and it was cut into circular pieces with a diameter of 19 mm for standby. Electrochemical tests showed that the room-temperature ionic conductivity of the composite solid electrolyte was 0.12 mS / cm, the electrochemical window reached 4.6 V, and the lithium ion transference number was 0.9. A composite membrane prepared from LLZO powder not compounded with polyfluorinated ethylene propylene and a polyimide non-woven membrane was used as a control group. The preparation method of the positive electrode sheet was as follows: 80 mg of lithium nickel manganate positive electrode powder, 10 mg of PVDF binder, and 10 mg of Ketjenblack conductive agent were uniformly dispersed in NMP solvent, ground in a mortar for 1 h, then coated on aluminum foil and vacuum dried at 100 °C for 24 h to obtain a lithium nickel manganate positive electrode sheet, which was cut into circular pieces with a diameter of 10 mm for standby. The preparation method of the solid electrolyte coating layer on the positive electrode surface was as follows: 1 g of polybenzimidazole-LLZO composite solid electrolyte powder was uniformly dispersed in 4 g of N-methylpyrrolidone solvent, and a uniform slurry was prepared by stirring at a speed of 3000 r / min at 300 °C for 1 h. It was coated on the positive electrode and then dried. The drying conditions were vacuum drying at 100 °C for 24 h. Finally, a 2016-type button battery was assembled with lithium nickel manganate coated with solid electrolyte as the positive electrode, metallic lithium as the negative electrode, and the solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 87% after 300 cycles at a 1C rate.

[0081] Example 4:

[0082] In this example, 2 g of poly(tetrafluoroethylene-ethylene), 1 g of Li3OCl powder were added to 10 g of N,N-dimethylformamide, and magnetically stirred at a speed of 1500 r / min for 5 h at room temperature to prepare an organic-inorganic composite solid electrolyte slurry. The slurry was coated on an aramid nonwoven membrane by the casting method and kept in a sealed container at 40 °C for 72 h to obtain an organic-inorganic composite solid electrolyte membrane. The thickness of the composite solid electrolyte membrane was 200 μm, and it was cut into circular pieces with a diameter of 19 mm for standby. 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 transference number was 0.91. A composite membrane prepared by compounding Li3OCl powder not compounded with poly(tetrafluoroethylene-ethylene) and an aramid nonwoven membrane was used as a control group. The preparation method of the positive electrode sheet was as follows: 80 mg of lithium cobaltate positive electrode powder, 8 mg of PVDF binder, 2 mg of poly(tetrafluoroethylene-ethylene)-Li3OCl composite solid electrolyte powder material and 10 mg of BLACK PEARLS2000 conductive agent were uniformly dispersed in NMP solvent, ground in a mortar for 1 h, then coated on nickel foam, and vacuum dried at 100 °C for 24 h to obtain a lithium cobaltate positive electrode sheet. The preparation method of the solid electrolyte coating layer on the positive electrode surface was as follows: 1 g of polybenzothiazole-Li3OCl composite solid electrolyte powder was uniformly dispersed in 9 g of NMP solvent, stirred at a speed of 100 r / min and at a temperature of 45 °C for 72 h to obtain a uniform slurry, and then coated on the positive electrode and dried. The drying conditions were vacuum at 100 °C for 24 h. The preparation method of the negative electrode sheet was as follows: 80 mg of graphite powder, 10 mg of PVDF binder and 10 mg of BLACK PEARLS2000 conductive agent were uniformly dispersed in NMP solvent, ground in a mortar for 1 h, then coated on nickel foam and vacuum dried at 100 °C for 24 h, and then cut into circular pieces with a diameter of 10 mm for standby. Then, a composite negative electrode was prepared by the melting method: metallic lithium was heated to 180 °C to melt, and the negative electrode sheet was infiltrated with the molten metallic lithium and cooled to room temperature. Finally, a soft-pack battery was assembled with lithium cobaltate coated with solid electrolyte as the positive electrode, graphite as the negative electrode, and the solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 80% after 50 cycles at a 1C rate.

[0083] Example 5:

[0084] In this example, 3 g of polytetrafluoroethylene and 0.2 g of Li2O·SiO2 powder were added to 10 g of dimethylacetamide, and the mixture was stirred evenly at a speed of 1600 r / min for 4 h at room temperature to obtain an organic-inorganic composite solid electrolyte slurry. The slurry was coated on a polypropylene nonwoven membrane by spin coating at a speed of 600 rpm / s and maintained in a sealed container at 120 °C for 18 h to obtain an organic-inorganic composite solid electrolyte membrane with a thickness of 50 μm, which was cut into circular pieces with a diameter of 19 mm for standby. Electrochemical tests 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 compounding Li2O·SiO2 powder not compounded with polytetrafluoroethylene and a polypropylene nonwoven membrane was used as a control group. The preparation method of the positive electrode sheet was as follows: 80 mg of NCM622 positive electrode powder, 7 mg of PVDF binder, 3 mg of polytetrafluoroethylene-Li2O·SiO2 composite solid electrolyte powder, and 10 mg of acetylene black conductive agent were evenly dispersed in NMP solvent, ground in a mortar for 1 h, and then coated on carbon-coated aluminum foil and vacuum dried at 120 °C for 24 h to obtain an NCM622 positive electrode sheet, which was cut into circular pieces with a diameter of 10 mm for standby. The preparation method of the solid electrolyte coating layer on the positive electrode surface was as follows: an LLZO coating with a thickness of 200 nm was prepared on the positive electrode sheet by magnetron sputtering. The preparation method of the negative electrode sheet was as follows: 80 mg of hard carbon powder, 10 mg of PVDF binder, and 10 mg of acetylene black conductive agent were evenly dispersed in NMP solvent, ground in a mortar for 1 h, and then coated on copper foil and vacuum dried at 120 °C for 24 h to obtain a hard carbon electrode sheet, which was cut into circular pieces with a diameter of 10 mm for standby. Subsequently, a lithium-containing composite negative electrode was prepared by an electrochemical method, and the constant current method was used to discharge at a current density of 0.1 mAcm -2 to 0.001 V to obtain a hard carbon composite negative electrode. Finally, a 2016-type button battery was assembled with the NCM622 positive electrode with a solid electrolyte coating layer, the hard carbon negative electrode, and the solid electrolyte composite membrane as the electrolyte, and the capacity retention rate was 94% after 300 cycles at a 1C rate.

[0085] Example 6:

[0086] In this example, 0.5 g of polyvinyl fluoride and 1 g of sodium lanthanum zirconium tantalum oxide powder were added to 10 g of N-methylpyrrolidone, and the mixture was stirred evenly at a speed of 1200 r / min for 4 h at room temperature to obtain an organic-inorganic composite solid electrolyte slurry. The slurry was coated on a cellulose membrane by a coating method and crosslinked and polymerized at a certain temperature. The conditions were to maintain it in a closed container at 100 °C for 24 h, and then an organic-inorganic composite solid electrolyte membrane was obtained. It was cut into circular pieces with a diameter of 19 mm for standby. The thickness of the composite solid electrolyte membrane was 40 μm. Electrochemical tests showed that the room-temperature ionic conductivity of the composite solid electrolyte was 0.13 mS / cm, the electrochemical window reached 4.7 V, and the sodium ion transference number was 0.93. A solid electrolyte membrane prepared from sodium lanthanum zirconium tantalum oxide powder not compounded with polyvinyl fluoride was used as a control group. The preparation method of the positive electrode sheet was 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 were evenly dispersed in NMP solvent. After grinding in a mortar for 1 h, it was coated on aluminum foil and vacuum dried at 100 °C for 24 h to obtain a sodium vanadium phosphate positive electrode sheet, which was cut into circular pieces with a diameter of 10 mm for standby. The preparation method of the solid electrolyte coating layer on the positive electrode surface was as follows: 1 g of polyvinyl fluoride-sodium lanthanum zirconium tantalum oxide composite solid electrolyte powder was evenly dispersed in 9 g of NMP solvent, and the mixture was stirred at a speed of 1500 r / min at 80 °C for 12 h to obtain a uniform slurry. Then it was coated on the positive electrode and dried. The drying conditions were vacuum drying at 100 °C for 24 h. Finally, a 2016-type button battery was assembled with sodium vanadium phosphate coated with solid electrolyte as the positive electrode, metallic sodium as the negative electrode, and the solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 89.4% after 300 cycles at a 1C rate.

[0087] Example 7:

[0088] In this example, 0.1 g of polyvinyl trifluoroethylene and 1 g of sodium lanthanum titanium oxide powder were mixed in 5 g of hexamethylphosphoramide, and uniformly stirred at a speed of 2500 r / min for 4 h at room temperature to obtain an organic-inorganic composite solid electrolyte slurry. The slurry was coated on a cellulose membrane by a coating method and crosslinked and polymerized at a certain temperature. The conditions were to keep it in a sealed container at 100 °C for 24 h, and then an organic-inorganic composite solid electrolyte membrane was obtained. It was cut into circular pieces with a diameter of 19 mm for standby. The thickness of the composite solid electrolyte membrane was 40 μm. 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 compounded with polyvinyl trifluoroethylene was used as a control group. The preparation method of the positive electrode sheet was as follows: 200 mg of Prussian blue positive electrode material powder, 25 mg of PVDF binder, and 25 mg of carbon nanofiber conductive agent were uniformly dispersed in NMP solvent. After magnetic stirring for 4 h, it was coated on aluminum foil and vacuum dried at 120 °C for 24 h to obtain a Prussian blue positive electrode sheet, which was cut into circular pieces with a diameter of 10 mm for standby. Finally, a 2032-type button battery was assembled with Prussian blue as the positive electrode, metallic sodium as the negative electrode, and the solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 83% after 300 cycles at a 1C rate.

[0089] Example 8:

[0090] In this example, 0.5 g of polyvinylidene chloride and 1 g of Na2O·Al2O3 powder were added to 10 g of hexamethylphosphorous triamide, and the mixture was stirred uniformly at a speed of 150 r / min at room temperature for 4 h to obtain an organic-inorganic composite solid electrolyte slurry. The slurry was coated on a glass plate with a scraper and subjected to crosslinking polymerization at a certain temperature. The conditions were as follows: maintaining for 1 h in a sealed container at 300 °C to obtain an organic-inorganic composite solid electrolyte membrane. The thickness of the composite solid electrolyte membrane was 100 μm, and it was cut into circular pieces with a diameter of 19 mm for standby. Through electrochemical testing, the room-temperature ionic conductivity of the composite solid electrolyte was 0.15 mS / cm, the electrochemical window reached 4.7 V, and the sodium ion transference number was 0.95. A solid electrolyte membrane prepared from Na2O·Al2O3 powder that was not compounded with polyvinylidene chloride was used as a control group. The preparation method of the positive electrode plate was as follows: 80 mg of polyanionic positive electrode powder, 10 mg of PVDF binder, 0.1 mg of polyvinylidene chloride-Na2O·Al2O3 electrolyte slurry binder, and 10 mg of Ketjenblack conductive agent were uniformly dispersed in NMP solvent, ground in a mortar for 1 h, then coated on an aluminum foil and vacuum dried at 100 °C for 24 h to obtain a positive electrode plate, which was cut into circular pieces with a diameter of 10 mm for standby. The preparation method of the solid electrolyte coating layer on the surface of the positive electrode was as follows: the prepared polyvinylidene chloride-Na2O·Al2O3 composite solid electrolyte slurry was coated on the positive electrode and then dried. The drying conditions were vacuum at 100 °C for 24 h. The preparation method of the negative electrode plate was as follows: 80 mg of hard carbon powder, 10 mg of PVDF binder, and 10 mg of acetylene black conductive agent were uniformly dispersed in NMP solvent, ground in a mortar for 1 h, then coated on a copper foil and vacuum dried at 120 °C for 24 h to obtain a hard carbon negative electrode plate. A hard carbon-sodium metal composite negative electrode was prepared by roll pressing at 300 °C and 20 MPa, and it was cut into circular pieces with a diameter of 10 mm for standby. Finally, a 2016-type button battery was assembled with the polyanionic positive electrode coated with solid electrolyte, the hard carbon negative electrode, and the solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 87% after 300 cycles at a 1C rate.

[0091] Example 9:

[0092] In this example, 2 g of poly(vinylidene chloride - hexachloropropylene), 1 g of K3OCl powder were added to 10 g of triethyl phosphate, and the mixture was stirred at a constant speed of 1500 r / min at room temperature for 24 h to prepare an organic - inorganic composite solid electrolyte slurry. The slurry was cast onto a polytetrafluoroethylene plate using the casting method and kept in a sealed container at 40 °C for 72 h to obtain an organic - inorganic composite solid electrolyte membrane. The thickness of the composite solid electrolyte membrane was 200 μm, and it was cut into circular pieces with a diameter of 19 mm for standby. 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 transference number was 0.9. A solid electrolyte membrane prepared from K3OCl powder not composite with poly(vinylidene chloride - hexachloropropylene) was used as a control group. The preparation method of the positive electrode plate was 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 h, then coated on nickel foam and vacuum - dried at 100 °C for 24 h to obtain the positive electrode plate. The preparation method of the solid electrolyte coating layer on the positive electrode surface was as follows: 1 g of organic - inorganic composite solid electrolyte was uniformly dispersed in 9 g of NMP solvent, stirred at a speed of 100 r / min at 45 °C for 72 h, and after obtaining a uniform slurry, it was coated on the positive electrode and dried. The drying conditions were vacuum - drying at 100 °C for 24 h. The preparation method of the negative electrode plate was as follows: 80 mg of silicon powder, 10 mg of PVDF binder, and 10 mg of BLACK PEARLS2000 conductive agent were uniformly dispersed in NMP solvent, ground in a mortar for 1 h, then coated on nickel foam and vacuum - dried at 100 °C for 24 h to obtain the negative electrode plate. Finally, a soft - pack battery was assembled with nickel - cobalt - manganese ternary coated with solid electrolyte as the positive electrode, silicon 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.

[0093] Example 10:

[0094] In this example, 3 g of poly(chloroethylenepropylene) and 0.2 g of K2O·SiO2 powder were added to 20 g of trimethyl phosphate, and the mixture was stirred evenly at a speed of 1500 r / min at room temperature for 4 h to obtain an organic-inorganic composite solid electrolyte slurry. The slurry was coated on a polypropylene non-woven membrane using a spatula and crosslinked and polymerized at a certain temperature. The conditions were to maintain it in a closed container at 120 °C for 18 h to obtain an organic-inorganic composite solid electrolyte membrane. The thickness of the composite solid electrolyte membrane was 40 μm, and it was cut into circular pieces with a diameter of 19 mm for standby. Electrochemical tests showed that the room-temperature ionic conductivity of the composite solid electrolyte was 0.12 mS / cm, the electrochemical window reached 4.5 V, and the potassium ion transference number was 0.9. A composite membrane prepared by compounding K2O·SiO2 powder not compounded with poly(chloroethylenepropylene) and a polypropylene non-woven membrane was used as a control group. The preparation method of the positive electrode plate was as follows: 85 mg of Prussian blue positive electrode powder, 7 mg of PVDF binder, 3 mg of poly(chloroethylenepropylene)-K2O·SiO2 electrolyte slurry, and 10 mg of acetylene black conductive agent were evenly dispersed in NMP solvent, ground in a mortar for 1 h, then coated on carbon-coated aluminum foil and vacuum dried at 120 °C for 24 h to obtain a Prussian blue positive electrode plate, which was cut into circular pieces with a diameter of 10 mm for standby. The preparation method of the solid electrolyte coating layer on the surface of the positive electrode was as follows: 1 g of poly(ethylene carbonate)-K2O·SiO2 composite solid electrolyte powder was evenly dispersed in 9 g of NMP solvent, and stirred evenly at a speed of 1500 r / min at 120 °C for 12 h to obtain a uniform slurry, which was coated on the positive electrode and then dried. The drying conditions were vacuum drying at 100 °C for 24 h. Finally, a 2016-type button battery was assembled with the Prussian blue positive electrode coated with solid electrolyte, a metal potassium negative electrode, and a solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 94% after 300 cycles at a 1C rate.

[0095] Example 11:

[0096] In this example, 0.5 g of poly(tetrachloroethylene-ethylene) and 1 g of lithium lanthanum zirconium tantalum oxide (LLZTO) powder were added to 10 g of propylene carbonate, and the mixture was stirred at a constant speed of 1500 r / min at room temperature for 4 h to obtain an organic-inorganic composite solid electrolyte slurry. The slurry was coated on a glass fiber membrane using a coating method and then crosslinked and polymerized at a certain temperature. The conditions were to maintain it in a sealed container at 100 °C for 24 h, and then an organic-inorganic composite solid electrolyte membrane was obtained. It was cut into circular pieces with a diameter of 19 mm for standby. The thickness of the composite solid electrolyte membrane was 40 μm. Electrochemical tests showed that the room-temperature ionic conductivity of the composite solid electrolyte was 0.11 mS / cm, the electrochemical window reached 4.9 V, and the lithium-ion transference number was 0.92. A composite membrane prepared from LLZTO powder not composite with poly(tetrachloroethylene-ethylene) and a glass fiber membrane was used as a control group. The preparation method of the positive electrode sheet was as follows: 80 mg of lithium manganate positive electrode powder with a surface layer having a precursor of poly(tetrachloroethylene-ethylene), 9 mg of styrene-butadiene rubber binder, 1 mg of poly(tetrachloroethylene-ethylene)-LLZTO composite solid electrolyte slurry, and 10 mg of Super P conductive agent were uniformly dispersed in 100 mg of NMP solvent. After grinding in a mortar for 1 h, it was coated on aluminum foil and vacuum dried at 100 °C for 24 h to obtain a lithium manganate positive electrode sheet, which was cut into circular pieces with a diameter of 10 mm for standby. The preparation method of the polymer surface layer on the surface of the positive electrode active material was to mix 0.5 g of poly(tetrachloroethylene-ethylene) and 0.5 g of lithium manganate powder in 2 g of NMP, and stir at a constant speed of 1500 r / min at room temperature for 4 h to obtain a suspension. The obtained suspension was stirred at a constant speed of 3000 r / min at 45 °C for 72 h to polymerize poly(tetrachloroethylene-ethylene) on the surface of the lithium manganate powder, and a lithium manganate suspension containing a surface layer was prepared. The suspension was placed in a vacuum oven at 40 °C and dried for 72 h to obtain a lithium manganate powder material with a surface layer having a precursor of poly(tetrachloroethylene-ethylene). The preparation method of the solid electrolyte coating layer on the positive electrode surface was as follows: 1 g of poly(vinylidene fluoride-hexafluoropropylene)-LiTFSI-LLZO (mass ratio 1:1:1) composite solid electrolyte was uniformly dispersed in 9 g of NMP solvent, and stirred at a speed of 1500 r / min at 45 °C for 12 h to obtain a uniform slurry. The prepared slurry was coated on the positive electrode and then dried. The drying conditions were vacuum drying at 100 °C for 24 h. The preparation method of the solid electrolyte coating layer on the negative electrode surface was as follows: 1 g of poly(vinylidene fluoride-hexafluoropropylene)-LiTFSI-LLZO (mass ratio 1:1:1) composite solid electrolyte was uniformly dispersed in 9 g of NMP solvent, and stirred at a speed of 1500 r / min at 45 °C for 12 h to obtain a uniform slurry. The prepared slurry was coated on the lithium negative electrode and then dried. The drying conditions were vacuum drying at 100 °C for 24 h.Finally, a 2016-type button battery was assembled with lithium manganate 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 85% after 300 cycles at a 1C rate.

[0097] Example 12:

[0098] In this example, 0.1 g of polyvinyl chloride and 1 g of lithium lanthanum titanium oxide (LLTO) powder were mixed in 4 g of propylene carbonate fluoride, and uniformly stirred at a rotation speed of 1500 r / min for 4 h at room temperature to obtain an organic-inorganic composite solid electrolyte slurry. The slurry was coated on a cellulose membrane using a coating method and then crosslinked and polymerized at a certain temperature. The conditions were to maintain it in a sealed container at 100 °C for 24 h, and then an organic-inorganic composite solid electrolyte membrane was obtained. It was cut into circular pieces with a diameter of 19 mm for standby. The thickness of the composite solid electrolyte membrane was 40 μm. 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 lithium-ion transference number was 0.9. A solid electrolyte membrane prepared from LLTO powder not compounded with polyvinyl chloride was used as a control group. The preparation method of the positive electrode sheet was as follows: 210 mg of NCM811 positive electrode powder with a surface layer having a precursor of polyvinyl chloride, 2.5 mg of polytetrafluoroethylene binder, 25 mg of polyvinyl chloride-LLTO composite solid electrolyte slurry, and 25 mg of carbon nanofiber conductive agent were uniformly dispersed in NMP solvent, magnetically stirred for 4 h, and then coated on aluminum foil and vacuum dried at 120 °C for 24 h to obtain an NCM811 positive electrode sheet, which was cut into circular pieces with a diameter of 10 mm for standby. The preparation method of the polymer surface layer on the surface of the positive electrode active material was to mix 0.5 g of polyvinyl chloride and 0.5 g of NCM811 powder in 2 g of NMP, and stir at a rotation speed of 1500 r / min for 4 h at room temperature to obtain a suspension. The obtained mixture suspension was uniformly stirred at a rotation speed of 3000 r / min at 45 °C for 72 h to polymerize polyvinyl chloride on the surface of the NCM811 powder, and an NCM811 suspension containing a surface layer was prepared. The suspension was placed in a vacuum oven at 40 °C and dried for 72 h to obtain an NCM811 powder material with a surface layer having a precursor of polyvinyl chloride. The preparation method of the solid electrolyte coating layer on the positive electrode surface was as follows: 1 g of cellulose-LiBOB-LiBH4 (mass ratio 1:1:1) composite solid electrolyte was uniformly dispersed in 9 g of NMP solvent, and stirred at a rotation speed of 1500 r / min at 45 °C for 12 h to obtain a uniform slurry. The prepared slurry was coated on the positive electrode and then dried. The drying conditions were vacuum drying at 100 °C for 24 h. The preparation method of the solid electrolyte coating layer on the negative electrode surface was as follows: 1 g of cellulose-LiBOB-LiBH4 (mass ratio 1:1:1) composite solid electrolyte was uniformly dispersed in 9 g of NMP solvent, and stirred at a rotation speed of 1500 r / min at 45 °C for 12 h to obtain a uniform slurry. The prepared slurry was coated on the lithium negative electrode and then dried. The drying conditions were vacuum drying at 100 °C for 24 h. 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 the solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 84.94% after 300 cycles at a 1C rate.

[0099] Example 13:

[0100] In this example, 0.5 g of polyvinylidene fluoride and 1 g of lithium lanthanum zirconium oxide (LLZO) powder were added to 10 g of acetonitrile, and the mixture was stirred evenly at a speed of 1500 r / min at room temperature for 4 h to prepare an organic-inorganic composite solid electrolyte slurry. The slurry was cast on a poly(difluorostyrene sulfonic acid) membrane using the casting method and crosslinked and polymerized at a certain temperature. The conditions were to maintain it in a closed container at 300 °C for 1 h, and then an organic-inorganic composite solid electrolyte membrane was obtained. The thickness of the composite solid electrolyte membrane was 100 μm, and it was cut into circular pieces with a diameter of 19 mm for standby. Electrochemical tests showed that the room-temperature ionic conductivity of the composite solid electrolyte was 0.12 mS / cm, the electrochemical window reached 4.6 V, and the lithium ion transference number was 0.9. A composite membrane prepared from LLZO powder not compounded with polyvinylidene fluoride and a poly(difluorostyrene sulfonic acid) membrane was used as a control group. The preparation method of the positive electrode sheet was as follows: 80 mg of lithium nickel manganate positive electrode powder with a surface layer having a precursor of polyvinylidene fluoride, 10 mg of sodium carboxymethyl cellulose binder, and 10 mg of Ketjenblack conductive agent were evenly dispersed in NMP solvent, ground in a mortar for 1 h, and then coated on an aluminum foil and vacuum-dried at 100 °C for 24 h to obtain a lithium nickel manganate positive electrode sheet, which was cut into circular pieces with a diameter of 10 mm for standby. The preparation method of the polymer surface layer on the surface of the positive electrode active material was to mix 0.5 g of polyvinylidene fluoride and 0.5 g of lithium nickel manganate powder in 2 g of NMP, and stir evenly at a speed of 1500 r / min at room temperature for 4 h to obtain a suspension. The obtained suspension was stirred evenly at a speed of 3000 r / min at 45 °C for 72 h to polymerize polyvinylidene fluoride on the surface of the lithium nickel manganate powder, and a lithium nickel manganate suspension containing a surface layer was prepared. The suspension was placed in a vacuum oven at 40 °C and dried for 72 h to obtain a lithium nickel manganate powder material with a surface layer having a precursor of polyvinylidene fluoride. The preparation method of the solid electrolyte coating layer on the positive electrode surface was as follows: 1 g of epoxy resin-LiPF6-Li3OCl (mass ratio 1:1:1) composite solid electrolyte powder was evenly dispersed in 4 g of N-methylpyrrolidone solvent, and stirred at a speed of 3000 r / min at 300 °C for 1 h to prepare a uniform slurry, which was coated on the positive electrode and then dried. The drying conditions were vacuum drying at 100 °C for 24 h. The preparation method of the solid electrolyte coating layer on the negative electrode surface was as follows: 1 g of epoxy resin-LiPF6-Li3OCl (mass ratio 1:1:1) composite solid electrolyte powder was evenly dispersed in 4 g of N-methylpyrrolidone solvent, and stirred at a speed of 3000 r / min at 300 °C for 1 h to prepare a uniform slurry, which was coated on the lithium negative electrode and then dried. The drying conditions were vacuum drying at 100 °C for 24 h. Finally, a 2016-type button battery was assembled with lithium nickel manganate coated with solid electrolyte as the positive electrode, metallic lithium as the negative electrode, and the solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 87% after 300 cycles at a 1C rate.

[0101] Example 14:

[0102] In this example, 2 g of poly(vinylidene fluoride - hexafluoropropylene), 1 g of Li3OCl powder were added to 10 g of ethanol, and the mixture was stirred at a constant speed of 1500 r / min at room temperature for 4 h to obtain an organic - inorganic composite solid electrolyte slurry. The slurry was coated on a PP film by the casting method and kept in a sealed container at 40 °C for 72 h to obtain an organic - inorganic composite solid electrolyte membrane. The thickness of the composite solid electrolyte membrane was 200 μm, and it was cut into circular pieces with a diameter of 19 mm for standby. 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 transference number was 0.91. A composite membrane prepared by compounding Li3OCl powder not compounded with poly(vinylidene fluoride - hexafluoropropylene) and a PP film was used as a control group. The preparation method of the positive electrode sheet was as follows: 80 mg of lithium cobaltate positive electrode powder with a surface layer having a precursor of poly(vinylidene fluoride - hexafluoropropylene), 8 mg of polyethylene binder, 2 mg of poly(vinylidene fluoride - hexafluoropropylene) - Li3OCl composite solid electrolyte powder material, and 10 mg of BLACK PEARLS2000 conductive agent were uniformly dispersed in NMP solvent, ground in a mortar for 1 h, then coated on nickel foam, and vacuum - dried at 100 °C for 24 h to obtain a lithium cobaltate positive electrode sheet. The preparation method of the polymer surface layer on the surface of the positive electrode active material was to mix 0.5 g of poly(vinylidene fluoride - hexafluoropropylene) and 0.5 g of lithium cobaltate powder in 2 g of NMP, and stir at a constant speed of 1500 r / min at room temperature for 4 h to obtain a suspension. The obtained suspension was stirred at a constant speed of 3000 r / min at 45 °C for 72 h to polymerize poly(vinylidene fluoride - hexafluoropropylene) on the surface of the lithium cobaltate powder, and a lithium cobaltate suspension containing a surface layer was prepared. The suspension was placed in a vacuum oven at 40 °C and dried for 72 h to obtain a lithium cobaltate powder material with a surface layer having a precursor of poly(vinylidene fluoride - hexafluoropropylene). The preparation method of the solid electrolyte coating layer on the positive electrode surface was as follows: 1 g of polybenzo - thiazole - LiClO4 - Li3InCl6 (mass ratio 1:1:1) composite solid electrolyte powder was uniformly dispersed in 9 g of NMP solvent, stirred at a speed of 100 r / min at 45 °C for 72 h to obtain a uniform slurry, and then coated on the positive electrode and dried. The drying conditions were vacuum - drying at 100 °C for 24 h. The preparation method of the negative electrode sheet was as follows: 80 mg of amorphous carbon powder, 10 mg of styrene - butadiene rubber binder, and 10 mg of BLACK PEARLS2000 conductive agent were uniformly dispersed in acetone solvent, ground in a mortar for 1 h, then coated on a stainless - steel mesh and vacuum - dried at 100 °C for 24 h, and then cut into circular pieces with a diameter of 10 mm for standby. Then, a composite negative electrode was prepared by the melting method. 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, an amorphous carbon composite negative electrode was obtained. Finally, a cylindrical battery was assembled with lithium cobaltate coated with solid electrolyte as the positive electrode, amorphous carbon as the negative electrode, and a solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 80% after 50 cycles at a 1C rate.

[0103] Example 15:

[0104] In this example, 3 g of polyfluorinated ethylene propylene and 0.2 g of Li2O·SiO2 powder were added to 20 g of tetrahydrofuran, and the mixture was stirred evenly at a speed of 1500 r / min at room temperature for 4 h to obtain an organic-inorganic composite solid electrolyte slurry. The slurry was coated on a perfluorosulfonic acid-polytetrafluoroethylene membrane by spin coating at a speed of 600 rpm / s and kept in a sealed container at 120 °C for 18 h, and then an organic-inorganic composite solid electrolyte membrane with a thickness of 50 μm was obtained and cut into circular pieces with a diameter of 19 mm for standby. The room temperature ionic conductivity of the composite solid electrolyte was measured by electrochemical test to be 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 compounding Li2O·SiO2 powder not compounded with polyfluorinated ethylene propylene with a perfluorosulfonic acid-polytetrafluoroethylene membrane was used as a control group. The preparation method of the positive electrode plate was as follows: 80 mg of lithium iron phosphate manganese oxide positive electrode powder, 7 mg of PVDF binder, 3 mg of polyfluorinated ethylene propylene-Li2O·SiO2 composite solid electrolyte powder and 10 mg of 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 vacuum dried at 120 °C for 24 h to obtain a lithium iron phosphate manganese oxide positive electrode plate, which was cut into circular pieces with a diameter of 10 mm for standby. The preparation method of the solid electrolyte coating layer on the surface of the positive electrode was as follows: an LLTO coating with a thickness of 200 nm was prepared on the surface of the positive electrode plate by magnetron sputtering. The preparation method of the negative electrode plate was as follows: 80 mg of mesophase carbon microsphere powder, 10 mg of polytetrafluoroethylene binder and 10 mg of acetylene black conductive agent were uniformly dispersed in cyclohexane solvent, ground in a mortar for 1 h, and then coated on nickel mesh and vacuum dried at 120 °C for 24 h to obtain a mesophase carbon microsphere negative electrode plate, which was cut into circular pieces with a diameter of 10 mm for standby. Then, a lithium-containing composite negative electrode was prepared by an electrochemical method, and the composite negative electrode was prepared by constant current discharge at a current density of 0.1 mA / cm -2 to 0.001 V. Finally, a 2016-type button battery was assembled with an NCM622 positive electrode with a solid electrolyte coating layer, a mesophase carbon microsphere negative electrode, and a solid electrolyte composite membrane as the electrolyte, and the capacity retention rate was 94% after 300 cycles at a 1C rate.

[0105] Example 16:

[0106] In this example, 0.5 g of polytetrafluoroethylene and 1 g of sodium lanthanum zirconium tantalum oxide powder were added to 10 g of diphenyl ether, and the mixture was stirred evenly at a speed of 1500 r / min at room temperature for 4 h to obtain an organic-inorganic composite solid electrolyte slurry. The slurry was coated on a cellulose membrane by a coating method and then crosslinked and polymerized at a certain temperature. The conditions were to keep it in a sealed container at 100 °C for 24 h, and then an organic-inorganic composite solid electrolyte membrane was obtained. It was cut into circular pieces with a diameter of 19 mm for standby. The thickness of the composite solid electrolyte membrane was 40 μm. Electrochemical tests showed that the room-temperature ionic conductivity of the composite solid electrolyte was 0.13 mS / cm, the electrochemical window reached 4.7 V, and the sodium ion transference number was 0.93. A solid electrolyte membrane prepared from sodium lanthanum zirconium tantalum oxide powder not compounded with polytetrafluoroethylene was used as a control group. The preparation method of the positive electrode sheet was as follows: 80 mg of sodium manganate positive electrode powder with a surface layer having a precursor of polytetrafluoroethylene, 1 mg of PVDF binder, 10 mg of electrolyte slurry, and 10 mg of Super P conductive agent were uniformly dispersed in NMP solvent. After grinding in a mortar for 1 h, it was coated on an aluminum foil and vacuum dried at 100 °C for 24 h to obtain a sodium manganate positive electrode sheet, which was cut into circular pieces with a diameter of 10 mm for standby. The preparation method of the polymer surface layer on the surface of the positive electrode active material was to mix 0.5 g of polytetrafluoroethylene and 0.5 g of sodium manganate positive electrode powder in 2 g of NMP, and stir evenly at a speed of 1500 r / min at room temperature for 4 h to obtain a suspension. The obtained suspension was stirred evenly at a speed of 3000 r / min at 45 °C for 72 h to polymerize polytetrafluoroethylene on the surface of the sodium manganate positive electrode powder, and a sodium manganate suspension containing a surface layer was prepared. The suspension was placed in a vacuum oven at 40 °C and dried for 72 h to obtain a sodium manganate powder material with a surface layer having a precursor of polytetrafluoroethylene. The preparation method of the solid electrolyte coating layer on the positive electrode surface was to prepare a sodium lanthanum zirconium oxide coating on the surface of the positive electrode sheet by magnetron sputtering, with a thickness of 200 nm. The preparation method of the solid electrolyte coating layer on the negative electrode surface was to prepare a sodium lanthanum zirconium oxide coating on the surface of the sodium negative electrode by magnetron sputtering, with a thickness of 200 nm. Finally, a 2016-type button battery was assembled with sodium manganate coated with solid electrolyte as the positive electrode, metallic sodium as the negative electrode, and the solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 89.4% after 300 cycles at a 1C rate.

[0107] Example 17:

[0108] In this example, 0.1 g of polyvinyl fluoride and 1 g of sodium lanthanum titanium oxide powder were mixed in 5 g of dimethyl sulfoxide, and stirred evenly at a speed of 1500 r / min for 4 h at room temperature to obtain an organic-inorganic composite solid electrolyte slurry. The slurry was coated on a cellulose membrane by a coating method and then crosslinked and polymerized at a certain temperature. The conditions were to keep it in a sealed container at 100 °C for 24 h, and then an organic-inorganic composite solid electrolyte membrane was obtained. It was cut into circular pieces with a diameter of 19 mm for standby. The thickness of the composite solid electrolyte membrane was 40 μm. 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 compounded with polyvinyl fluoride was used as a control group. The preparation method of the positive electrode sheet was as follows: 200 mg of Prussian blue positive electrode material powder, 25 mg of PVDF binder, and 25 mg of carbon nanofiber conductive agent were uniformly dispersed in NMP solvent, magnetically stirred for 4 h, and then coated on aluminum foil and vacuum dried at 120 °C for 24 h to obtain a Prussian blue positive electrode sheet, which was cut into circular pieces with a diameter of 10 mm for standby. The preparation method of the solid electrolyte coating layer on the positive electrode surface was as follows: a sodium lanthanum titanium oxide coating with a thickness of 200 nm was prepared on the positive electrode sheet surface by a vapor deposition method. The preparation method of the solid electrolyte coating layer on the negative electrode surface was as follows: a sodium lanthanum titanium oxide coating with a thickness of 200 nm was prepared on the sodium negative electrode surface by a vapor deposition method. Finally, a 2032-type button battery was assembled with Prussian blue as the positive electrode, metallic sodium as the negative electrode, and the solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 83% after 300 cycles at a 1C rate.

[0109] Example 18:

[0110] In this example, 0.5 g of polyvinyl trifluoroethylene and 1 g of Na2O·Al2O3 powder were added to 10 g of N,N-dimethylformamide, and the mixture was stirred evenly at a speed of 1500 r / min at room temperature for 4 h to obtain an organic-inorganic composite solid electrolyte slurry. The slurry was coated on a glass plate with a scraper and crosslinked and polymerized at a certain temperature. The conditions were to keep it in a closed container at 300 °C for 1 h, and then an organic-inorganic composite solid electrolyte membrane was obtained. The thickness of the composite solid electrolyte membrane was 100 μm, and it was cut into circular pieces with a diameter of 19 mm for standby. Electrochemical tests showed that the room-temperature ionic conductivity of the composite solid electrolyte was 0.15 mS / cm, the electrochemical window reached 4.7 V, and the sodium ion transference number was 0.95. A solid electrolyte membrane prepared with Na2O·Al2O3 powder not compounded with polyvinyl trifluoroethylene was used as a control group. The preparation method of the positive electrode plate was as follows: 80 mg of sodium manganese phosphate positive electrode powder, 10 mg of PVDF binder, 0.1 mg of polyvinyl trifluoroethylene-Na2O·Al2O3 electrolyte slurry binder, and 10 mg of Ketjenblack conductive agent were evenly dispersed in NMP solvent, ground in a mortar for 1 h, then coated on aluminum foil and vacuum dried at 100 °C for 24 h to obtain a positive electrode plate, which was cut into circular pieces with a diameter of 10 mm for standby. The preparation method of the solid electrolyte coating layer on the positive electrode surface was as follows: 1 g of polybenzothiazole-NaClO4-Na3InCl6 (mass ratio 1:1:1) composite solid electrolyte powder was evenly dispersed in 9 g of NMP solvent, stirred at a speed of 100 r / min at 45 °C for 72 h to obtain a uniform slurry, and then coated on the positive electrode and dried. The drying conditions were vacuum drying at 100 °C for 24 h. The preparation method of the negative electrode plate was as follows: 80 mg of tin-silicon alloy powder, 10 mg of sodium carboxymethyl cellulose binder, and 10 mg of acetylene black conductive agent were evenly dispersed in ethanol solvent, ground in a mortar for 1 h, then coated on carbon cloth and vacuum dried at 120 °C for 24 h to obtain a tin-silicon alloy negative electrode plate. A tin-silicon alloy-sodium metal composite negative electrode was prepared by a roll pressing method at 300 °C and 20 MPa, and it was cut into circular pieces with a diameter of 10 mm for standby. Finally, a 2016-type button battery was assembled with 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.

[0111] Example 19:

[0112] In this example, 2 g of polyvinylidene chloride and 1 g of K3OCl powder were added to 10 g of dimethylacetamide, and the mixture was stirred uniformly at a speed of 1500 r / min for 4 h at room temperature to obtain an organic-inorganic composite solid electrolyte slurry. The slurry was cast on a stainless-steel plate using the casting method and kept in a sealed container at 40 °C for 72 h. Subsequently, an organic-inorganic composite solid electrolyte membrane was obtained. The thickness of the composite solid electrolyte membrane was 200 μm, and it was cut into circular pieces with a diameter of 19 mm for standby. 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 transference number was 0.9. A solid electrolyte membrane prepared from K3OCl powder not composite with polyvinylidene chloride was used as the control group. The preparation method of the positive electrode plate was as follows: 80 mg of nickel cobalt manganese positive electrode powder with a surface layer having polyvinylidene chloride as the precursor, 10 mg of PVDF binder, 0.01 mg of the organic-inorganic composite solid electrolyte slurry, and 10 mg of BLACK PEARLS2000 conductive agent were uniformly dispersed in NMP solvent. After grinding in a mortar for 1 h, it was coated on nickel foam and vacuum dried at 100 °C for 24 h to obtain the positive electrode plate. The preparation method of the polymer surface layer on the surface of the positive electrode active material was to mix 0.5 g of polyvinylidene chloride and 0.5 g of nickel cobalt manganese positive electrode powder in 2 g of NMP, and stir uniformly at a speed of 1500 r / min for 4 h at room temperature to obtain a suspension. The obtained suspension was stirred uniformly at a speed of 3000 r / min at 45 °C for 72 h to polymerize polyvinylidene chloride on the surface of the nickel cobalt manganese positive electrode powder, and a nickel cobalt manganese suspension containing a surface layer was prepared. The suspension was placed in a vacuum oven at 40 °C and dried for 72 h to obtain a nickel cobalt manganese powder material with a surface layer having polyvinylidene chloride as the precursor. The preparation method of the solid electrolyte coating layer on the positive electrode surface was as follows: 1 g of poly(ethylene carbonate)-KClO4 (mass ratio 1:1) composite solid electrolyte powder was uniformly dispersed in 9 g of NMP solvent, stirred at a speed of 100 r / min at 45 °C for 72 h to obtain a uniform slurry, and then coated on the positive electrode and dried. The drying conditions were vacuum drying at 100 °C for 24 h. The preparation method of the negative electrode plate was as follows: 80 mg of copper silicon alloy powder, 10 mg of polyolefin binder, and 10 mg of BLACK PEARLS2000 conductive agent were uniformly dispersed in tetrahydrofuran solvent. After grinding in a mortar for 1 h, it was coated on a carbon plate and vacuum dried at 100 °C for 24 h to obtain the negative electrode plate. The preparation method of the solid electrolyte coating layer on the negative electrode surface was as follows: 1 g of poly(ethylene carbonate)-KClO4 (mass ratio 1:1) composite solid electrolyte powder was uniformly dispersed in 9 g of NMP solvent, stirred at a speed of 100 r / min at 45 °C for 72 h to obtain a uniform slurry, and then coated on the negative electrode and dried. The drying conditions were vacuum drying at 100 °C for 24 h. Finally, a soft-pack battery was assembled with the nickel cobalt manganese ternary coated with solid electrolyte as the positive electrode, 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.

[0113] Example 20:

[0114] In this example, 3 g of poly(vinylidene chloride - hexachloropropylene), 0.2 g of K2O·SiO2 powder were added to 20 g of N - methylpyrrolidone, and the mixture was stirred evenly at a speed of 1500 r / min for 4 h at room temperature to obtain an organic - inorganic composite solid electrolyte slurry. The slurry was coated on the Nafion membrane using a scraper and maintained in a sealed container at 120 °C for 18 h to obtain an organic - inorganic composite solid electrolyte membrane. The thickness of the composite solid electrolyte membrane was 40 μm, and it was cut into circular pieces with a diameter of 19 mm for standby. Electrochemical tests showed that the room - temperature ionic conductivity of the composite solid electrolyte was 0.12 mS / cm, the electrochemical window reached 4.5 V, and the potassium ion transference number was 0.9. A composite membrane prepared by compounding K2O·SiO2 powder not compounded with poly(vinylidene chloride - hexachloropropylene) with the Nafion membrane was used as a control group. The preparation method of the positive electrode plate was as follows: 85 mg of Prussian blue positive electrode powder, 7 mg of PVDF binder, 3 mg of poly(vinylidene chloride - hexachloropropylene) - K2O·SiO2 electrolyte slurry, and 10 mg of acetylene black conductive agent were evenly dispersed in the NMP solvent, ground in a mortar for 1 h, then coated on carbon - coated aluminum foil and vacuum - dried at 120 °C for 24 h to obtain a Prussian blue positive electrode plate, which was cut into circular pieces with a diameter of 10 mm for standby. The preparation method of the solid electrolyte coating layer on the positive electrode surface was as follows: 1 g of Nafion was evenly dispersed in 9 g of NMP solvent, stirred at a speed of 1500 r / min at 120 °C for 12 h to obtain a uniform slurry, which was coated on the positive electrode and then dried. The drying conditions were vacuum - drying at 100 °C for 24 h. The preparation method of the solid electrolyte coating layer on the negative electrode surface was as follows: 1 g of Nafion was evenly dispersed in 9 g of NMP solvent, stirred at a speed of 1500 r / min at 120 °C for 12 h to obtain a uniform slurry, which was coated on the negative electrode and then dried. The drying conditions were vacuum - drying at 100 °C for 24 h. Finally, a 2016 - type button battery was assembled with the Prussian blue positive electrode coated with solid electrolyte, the metal potassium negative electrode, and the solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 94% after 300 cycles at a 1C rate.

Claims

1. An in-situ polymerized organic-inorganic composite electrolyte, characterized in that: The in-situ polymerized organic-inorganic composite electrolyte consists of an inorganic oxide solid electrolyte capable of conducting alkali metal cations, an unsaturated polymer formed by in-situ crosslinking on its surface from a halogen-containing polymer reaction, and a polar organic solvent; the mass ratio of the inorganic oxide solid electrolyte to the halogen-containing polymer is 1:0.1 to 15 (preferably 1:0.5 to 10, more preferably 1:1 to 5); the mass ratio of the polar organic solvent to the halogen-containing polymer is 5 to 50:1 (preferably 10 to 30:1, more preferably 15 to 25:1); The oxygen atoms in the inorganic oxide solid electrolyte are Lewis bases, including xA2O·yMO n (A is one or more of Li, Na, or K; M is one or more of Si, B, Ge, Zr, Al, Ga, Ti, P, S, As, Se, Nb, Sn, Sb, Te, Nd, Y, I, La, 0.6 < x < 5, 1 < y < 4). The garnet-type inorganic solid electrolyte includes A 7-m La3Zr 2-m M m O 12 (A is one or more of Li, Na, or K; M = one or two of Ta, Nb; 0 ≤ m ≤ 2), A 7-2n La3Zr 2-n N n O 12 (A is one or more of Li, Na, or K; N = one or two of W, Mo; 0 ≤ n ≤ 2), A 7-3d D d La3Zr2O 12 (A is one or more of Li, Na, or K; D = one or two of Ga, Al; 0 ≤ d ≤ 7 / 3); the perovskite-type inorganic solid electrolyte A 3x La 0.67-x TiO3(0.04 < x < 0.17)(A is one or more of Li, Na, or K) and one or more of the anti-perovskite-type inorganic solid electrolyte A3OX (A is one or more of Li, Na, or K; X = one or more of Cl, Br, or I); the particle size of the oxide solid electrolyte is 1 nm to 100 μm; the room temperature ionic conductivity is not less than 10 -4 mS / cm. The oxide solid electrolytes are all single-ion conductor solid electrolytes, and the alkali metal cation transference number, that is, the percentage of the charge transferred by the alkali metal cations in the total charge, is 1; The halogen-containing polymer is a polymer containing halogen atoms (including one or two of F and Cl), including one or more of polyvinylidene fluoride, poly(vinylidene fluoride - hexafluoropropylene), polyfluorinated ethylene-propylene, poly(tetrafluoroethylene - ethylene), polytrifluoroethylene, polyvinyl fluoride, polyvinyl trifluoroethylene, polyvinylidene chloride, poly(vinylidene chloride - hexachloropropylene), polyvinyl chloride-ethylene, poly(tetrachloroethylene - ethylene), polyvinyl chloride, etc.; the molecular weight of the polymer is 1000 to 10000000; The polar organic solvents include one or more of acetonitrile, ethanol, tetrahydrofuran, diphenyl ether, dimethyl sulfoxide, N,N-dimethylformamide, dimethylacetamide, N-methylpyrrolidone, hexamethylphosphorous triamide, hexaethylphosphorous triamide, triethyl phosphate, trimethyl phosphate, propylene carbonate, fluorinated propylene carbonate.

2. The in-situ polymerized organic-inorganic composite electrolyte according to claim 1, characterized in that: The thickness of the organic-inorganic composite solid electrolyte membrane is 1 to 500 μm. When coated on a flat plate or a dense membrane, the measured thickness is the thickness of the organic-inorganic composite solid electrolyte; The unsaturated polymer is formed by an in-situ reaction after the halogen-containing polymer contacts the inorganic oxide solid electrolyte. The reaction process is as follows: Where A and B can be H, halogen atoms (including one or two of F and Cl) respectively, and X is a halogen atom (including one or two of F and Cl); D is a haloalkyl chain segment C y H z M (2y-z) , where M is one or two of F or Cl atoms, 0 ≤ y ≤ 3 (when y is 0, the polymer chain has only -CAX-CHB- as the repeating unit), 0 ≤ z ≤ 2y, and both y and z are integers.

3. The in-situ polymerized organic-inorganic composite electrolyte according to claim 1, characterized in that: The organic-inorganic composite solid electrolyte membrane is attached to a membrane-like skeleton material; the membrane-like skeleton material can be a dense membrane or a porous membrane. The dense membrane can be a composite membrane composed of one or more of Nafion membrane, perfluorosulfonic acid-polytetrafluoroethylene membrane, polytrifluorostyrenesulfonic acid membrane, polydifluorostyrenesulfonic acid membrane, polyaryletherketone sulfonic acid membrane, polyimide sulfonic acid membrane, sulfonated polysulfone membrane; the porous membrane can be a composite membrane composed of one or more of PP membrane, PE membrane, cellulose non-woven membrane, polyimide non-woven membrane, seaweed fiber non-woven membrane, aramid non-woven membrane, polyarylsulfonamide non-woven membrane, polypropylene non-woven membrane, glass fiber membrane, polyethylene terephthalate non-woven membrane.

4. A preparation method of the in-situ polymerized organic-inorganic composite electrolyte according to any one of claims 1-3, characterized in that: On the surface of the oxide solid electrolyte, the unsaturated polymer is in-situ polymerized and crosslinked; the halogen-containing polymer is mixed with the inorganic oxide solid electrolyte powder material. At a certain temperature, the oxygen atoms on the surface of the inorganic oxide solid electrolyte that are Lewis bases induce the halogen-containing polymer to remove halogen elements, and an unsaturated polymer containing C=C groups is in-situ generated; The specific preparation process includes the following steps: (1) The oxide solid electrolyte powder material, halogen-containing polymer, and polar organic solvent are stirred at a rotation speed of 100 - 3000 r / min at room temperature for 1 - 72 h to be fully mixed to obtain a suspension. The rotation speed is preferably 1200 - 1600 r / min, and the time is preferably 8 - 16 h; (2) The slurry prepared in step (1) is coated onto a flat or membrane-like framework material by casting method, tape casting method, spin coating method, or coating method, and is in-situ crosslinked and polymerized in a sealed container at a temperature of 40 - 300 °C to form a separator, and the treatment time is 1 - 72 h.

5. A solid electrolyte membrane using the in-situ polymerized organic-inorganic composite electrolyte according to claim 1, characterized in that: The alkali metal cation transference number is not less than 0.

9.

6. An application of the in-situ polymerized organic-inorganic composite electrolyte according to any one of claims 1-3, characterized in that: It is used as a separator for assembling a solid-state battery.

7. The application according to claim 5, characterized in that: The solid-state battery is composed of a positive electrode, an in-situ polymerized organic-inorganic composite 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 on its surface, a conductive agent, and a binder; The positive electrode active material is lithium iron phosphate, lithium iron manganese phosphate, lithium cobalt oxide, lithium manganese oxide, nickel cobalt manganese ternary material, lithium nickel manganese oxide, transition metal oxide A x MO2 (A is Na or K, and M is one or more of Co, Fe, Mn, Ni, etc.), polyanion compound A X M Y (X a O b )Z w (A is Na or K, M is one or more of Ti, V, Cr, Mn, Fe, Co, Ni, Ca, Mg, Al, Nb, etc., X is Si, S, P, As, B, Mo, W, Ge, etc., Z is F, O, H, etc.), Prussian blue compound A x M1[M2(CN)6] 1-y (A is Na or K, M1 and M2 are Mn, Fe, Co, Ni, Cu, Zn, etc.), a composite positive electrode composed of one or more of them; The polymer surface layer on the surface of the positive electrode active material is an in-situ crosslinked unsaturated polymer; The preparation method of the polymer surface layer on the surface of the positive electrode active material is: adding a halogen-containing polymer and a positive electrode active substance containing a Lewis base oxygen atom into a solvent, stirring to obtain a mixture, and under certain conditions, the Lewis base oxygen atom in the positive electrode active material induces the precursor to undergo a polymerization reaction to in-situ crosslink and generate a polymer coating layer, and drying the solvent to obtain a positive electrode material powder with a surface layer; the specific preparation methods include: The positive electrode active material containing a Lewis base oxygen atom includes lithium cobaltate, lithium manganate, nickel cobalt manganese ternary material, lithium nickel manganate, transition metal oxide A x MO2 (where A is Na or K, and M is one or more of Co, Fe, Mn, Ni, etc.), and the mixture is stirred at a rotation speed of 100 to 3000 r / min and a temperature of 45°C to 300°C for 1 to 72 h. The rotation speed is preferably 1200 to 1600 r / min, the temperature is preferably 85 to 95°C, and the time is preferably 10 to 14 h to form an in-situ crosslinked polymer layer; The conductive agent is one or more of acetylene black, BLACK PEARLS2000, Ketjenblack, Super-P, carbon nanotubes, carbon nanofibers, activated carbon, graphene; The binder is a composite 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: mixing the positive electrode active material with or without a surface layer attached to its surface, a conductive agent, a binder, and a solvent by stirring, grinding, or ball milling to form a slurry, coating the slurry onto the surface of a current collector by casting method, tape casting method, spin coating method, or coating method, and drying to obtain a positive electrode plate; the solvents used include one or more of deionized water, ethanol, acetone, acetonitrile, cyclohexane, tetrahydrofuran, diphenyl ether, dimethyl sulfoxide, N,N-dimethylformamide, dimethylacetamide, N-methylpyrrolidone, hexamethylphosphorous triamide, and hexaethylphosphorous triamide; The current collector is one of aluminum foil, carbon-coated aluminum foil, nickel foam, or titanium foil; There is a solid electrolyte intermediate layer or no intermediate layer between the positive electrode of the solid-state battery and the organic-inorganic composite solid electrolyte membrane; The solid electrolyte interlayer between the positive electrode and the in-situ polymerized 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; the inorganic solid electrolyte includes inorganic oxide solid electrolytes, including xA2O·yMO n (A is Li, Na or K; M is one or more of Si, B, Ge, Zr, Al, Ga, Ti, P, S, As, Se, Nb, Sn, Sb, Te, Nd, Y, I, La, 0.6 < x < 5, 1 < y < 4), the garnet-type inorganic solid electrolyte includes A 7-m La3Zr 2-m M m O 12 (A is Li, Na or K; M = Ta, Nb; 0 ≤ m ≤ 2), A 7-2n La3Zr 2-n N n O 12 (A is Li, Na or K; N = W, Mo; 0 ≤ n ≤ 2), A 7-3d D d La3Zr2O 12 (A is Li, Na or K; D = Ga, Al; 0 ≤ d ≤ 7 / 3); the perovskite-type inorganic solid electrolyte A 3x La 0.67-x TiO3(0.04 < x < 0.17)(A is Li, Na or K) and the anti-perovskite-type inorganic solid electrolyte A3OX(A is Li, Na or K; X = Cl, Br or I), β-A3PS4(A is Li, Na or K), A7P3S 11 (A is Li, Na or K), thio-LISICON-type A 10±1 MP2X 12 (A is Li, Na or K; M = Ge, Si, Sn, Al or P; X = S or Se), Argyrodite-type A6PS5X(A is Li, Na or K; X = Cl, Br or I), A3YX6(A is Li, Na or K; X = Cl, Br or I), ABH4(A is Li, Na or K), ABH4-AX(A is Li, Na or K; X = Cl, Br or I), ACB 11 H 12 (A is Li, Na or K), AM(BH4)3Cl(A is Li, Na or K; M is one or more of La, Ce or Gd) and A2B 12 H 12 (A is Li, Na or K) one or more of; The polymer includes one or more of polyolefin, polyvinylidene fluoride, poly(vinylidene fluoride - hexafluoropropylene), cellulose, epoxy resin, polyacrylonitrile, poly(ethylene carbonate), poly(ethylene carbonate), polyimide, polystyrene, polysulfone, poly(aryl ether ketone), poly(aryl ether sulfone), polybenzimidazole, and polybenzothiazole; The alkali metal salts include one or more of ATFSI, AFSI, ABOB, APF6, AClO4, AAsF6, ABF4, ACH3SO3, ACF3SO3, AC4BO8, AC2BF2O4 (where A is Li, Na or K); The negative electrode is one of an alkali metal negative electrode or an alkali metal composite negative electrode; The alkali metal is Li, Na or K; The composite negative electrode is composed of an alkali metal and a conductive skeleton material; The conductive skeleton materials are 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, The three-dimensional self-supporting materials include one or more of stainless steel mesh, copper mesh, nickel mesh, nickel foam, copper foam, carbon cloth, carbon fiber felt, carbon plate, graphene, electrospun organic polymer fiber cloth; The carbon-based materials are one or more than two of graphite, amorphous carbon, mesophase carbon microspheres, hard carbon, soft carbon; The silicon-based materials are one or more than two 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, gallium-silicon alloy; The binder is a composite composed of one or more of styrene-butadiene rubber, polytetrafluoroethylene, sodium carboxymethyl cellulose, polyolefin, polyvinylidene fluoride and its derivatives, organic-inorganic composite electrolyte; The preparation method of the composite skeleton material is: mixing the carbon-based material or silicon-based material, conductive agent, binder and solvent by stirring, grinding or ball milling to make a slurry, and coating the slurry on the surface of a copper foil or titanium foil current collector by casting method, doctor blade method, spin coating method or coating method, and drying to obtain a negative electrode sheet; the solvents used include one or more of deionized water, ethanol, acetone, acetonitrile, cyclohexane, tetrahydrofuran, diphenyl ether, dimethyl sulfoxide, N,N-dimethylformamide, dimethylacetamide, N-methylpyrrolidone, hexamethylphosphorous triamide, hexaethylphosphorous triamide; The composite negative electrode is prepared by introducing an alkali metal into the conductive skeleton by means of electrochemical deposition of an alkali metal, molten infiltration of an alkali metal or pressure filling of an alkali metal; Between the alkali metal negative electrode or composite negative electrode of the solid-state battery and the in-situ polymerized organic-inorganic composite solid electrolyte membrane, there is a solid electrolyte interlayer or there is no interlayer; 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, a lithium salt-polymer composite solid electrolyte; The solid-state battery is assembled into a solid-state battery by laminating or winding the negative electrode, the organic-inorganic composite solid electrolyte separator and the positive electrode. The battery can be a button cell, a square soft-pack battery, a square shell battery or a cylindrical battery.

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