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

Abstract

The present application relates to an organic-inorganic composite solid electrolyte and a preparation method thereof, which is prepared by compounding an oxide solid electrolyte, an unsaturated polymer crosslinked in situ on the surface of the oxide solid electrolyte, and a polar organic solvent, so as to prepare an organic-inorganic composite solid electrolyte with higher room-temperature ionic conductivity and a wider electrochemical window. The composite solid electrolyte prepared by the present application has a room-temperature ionic conductivity of 0.1 mS / cm or higher, an electrochemical window of greater than 4.5 V, and an alkali metal cation transference number of greater than 0.9. In addition, the composite solid electrolyte is easy to be formed into a film, and the composite solid electrolyte film prepared has a thin thickness. A solid-state alkali metal battery assembled with the electrolyte film has good interface stability with the positive and negative electrodes, and can inhibit the growth of alkali metal dendrites, thereby significantly improving the performance of the battery.

Description

TECHNICAL FIELD

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

[0002] The growing 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 working voltage. The organic liquid electrolyte frequently used in commercial lithium-ion batteries is volatile and flammable, which can cause leakage and fire safety problems. The lithium metal anode, known as the "holy grail", has strong reactivity, which can cause dendrite growth and continuous side reactions. Solid-state electrolytes can replace flammable liquid electrolytes, thereby effectively improving safety, and are suitable for adaptation with lithium metal anodes, which are highly expected.

[0003] Solid-state electrolytes can be divided into two categories: polymer solid-state electrolytes and inorganic solid-state electrolytes. Single solid-state electrolytes are difficult to meet all the requirements of lithium metal batteries, such as sufficient ionic conductivity (>10-4S cm-1), high working voltage (up to 4-5V for Li / Li+ voltage), 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 are prone to crystallization at ambient temperature, and have limited ionic conductivity. The thermodynamic instability of the interface also limits their compatibility with high-voltage positive electrode materials, and the poor mechanical properties also cannot inhibit the growth of dendrites. Inorganic solid-state electrolytes have high ionic conductivity, wide electrochemical window, and high mechanical strength, but their brittleness leads to the fragile nature of inorganic electrolytes, which results in poor processability and large contact resistance. In recent years, researchers have been committed to compounding inorganic fillers into polymer solid-state electrolytes to form polymer / inorganic composite electrolytes, realizing the synergistic effect of different materials. The inorganic fillers not only increase the mechanical strength of the polymer matrix, but also act as plasticizers to prevent the polymer from crystallizing and improve the ionic conductivity of the electrolyte.

[0004] For example, CN202311194380.2 discloses a preparation method of a polytrimethylene carbonate-based polyurethane / ceramic composite electrolyte. In an inert gas atmosphere, trimethylene carbonate monomer and initiator are added to solvent I and stirred uniformly, then catalyst I is added and reacted at 25-110°C for 2-12h; the homopolymer hydroxyl polytrimethylene carbonate is prepared; the hydroxyl polytrimethylene carbonate is dissolved in solvent II, lithium salt, diisocyanate and inorganic ceramic particles are added and stirred uniformly, then inorganic ceramic particles are uniformly dispersed, catalyst II is added and stirred uniformly to obtain an electrolyte precursor solution; drying in a vacuum oven obtains a polytrimethylene carbonate-based polyurethane / ceramic composite electrolyte. Here, the organic-inorganic composite electrolyte is prepared by multi-step catalytic polymerization. CN202311151352.2 discloses a composite solid electrolyte membrane and its preparation method and application. The continuous network structure filled with gelatin provides a stable framework for SPE like steel bars, and PVN acts as a cement for the polymer electrolyte matrix, forming an extremely stable “reinforced concrete” structure of PVN-gelatin through hydrogen bond interaction, which can fully utilize the high strength characteristics of gelatin and comprehensively improve the electrochemical performance of the composite electrolyte membrane. In addition, PVN in the system provides a large number of C=O and C-O to coordinate with Li+, thereby promoting the conduction of Li+, which can be used as a solid-state electrolyte membrane material. Compared with the prior art, the present application forms a uniform three-dimensional Li+ conductive network in the PVN matrix by adding an appropriate amount of gelatin, and constructs a new fast ion transmission channel, thereby improving the ion migration number and ionic conductivity of the electrolyte. CN202311130617.0 discloses a preparation method of an ultrathin continuous network structure composite electrolyte membrane. A coaxial electrospinning method is used to construct a core-shell structure, and inorganic fillers are embedded on the surface of the spinning fiber to construct a 3D filler continuous ion migration network support skeleton under low filling amount, wherein the polymer is the core and the inorganic filler is the shell. Then, an in-situ thermosetting polymer / lithium salt pre-solid solution is poured into the support skeleton to prepare a solid composite electrolyte film, and the final thickness of the composite film is only 11-25μm. The present application effectively prepares a 3D continuous lithium ion transfer network through a coaxial electrospinning process, and the preparation process is simple. The inorganic fillers are concentrated on the surface of the polymer fiber, which reduces the crystallinity of the polymer, and the interaction between the continuous inorganic fillers and the lithium salt and the polymer increases the lithium ion transmission channel, thereby improving the ionic conductivity of the composite solid electrolyte. The polymer composite electrolyte film obtained has high lithium ion conductivity at room temperature. In the above patents, inorganic solid electrolyte and in-situ polymerized polymer electrolyte are used to prepare a composite solid electrolyte, which has good ionic conductivity, and the film-forming property and interface stability of the solid electrolyte are optimized. However, the double-ion conduction characteristics of the polymer electrolyte containing alkali metal cation salt can cause concentration polarization of the alkali metal cation inside the solid electrolyte, and finally produce alkali metal dendrites.In addition, catalysts and initiators are used in the in-situ polymerization process, which not only leads to a more complex process, but also residual initiators can cause additional side reactions inside the battery. Therefore, it is of great significance to develop new solid electrolytes to achieve in-situ crosslinking polymerization of polymers without adding initiators, while obtaining the interface stability of the electrode / solid electrolyte, for the construction of high-performance solid-state batteries. SUMMARY

[0005] The purpose of the present application is to develop an in-situ crosslinking polymerization of organic-inorganic composite electrolyte and its preparation method, to realize high ionic conductivity, wide electrochemical window, small interface impedance with electrode and effective inhibition of alkali metal dendrite growth of composite electrolyte, and to promote the industrialization of solid-state batteries.

[0006] The in-situ polymerized organic-inorganic composite electrolyte consists of an inorganic oxide solid electrolyte that can conduct alkali metal cations, an unsaturated polymer generated by the reaction of a halogen-containing polymer on its surface that occurs in-situ crosslinking, and a polar organic solvent; the mass ratio of inorganic oxide solid electrolyte to halogen-containing polymer is 1:0.1-15 (preferably 1:0.5-10, more preferably 1:1-5); the mass ratio of polar organic solvent to 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 two 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 7-m La3Zr 2-m M m O 12 (A is one or two or more of Li, Na or K; M = one or two of Ta, Nb; 0 7-2n La3Zr 2-n N n O 12 (A is one or two or more of Li, Na or K; N = one or two of W, Mo; 0 7-3d D d La3Zr2O 12 (A is one or two or more of Li, Na or K; D = one or two of Ga, Al; 0 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 -4 mS / cm; the oxide solid electrolyte is a single-ion conductor solid electrolyte, and the alkali metal cation transference number, i.e. the percentage of the charge transferred by the alkali metal cation in the total charge, is 1;

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

[0009] The polar organic solvent includes one or more of acetonitrile, ethanol, tetrahydrofuran, diphenyl ether, dimethyl sulfoxide, N,N-dimethylformamide, dimethylacetamide, N-methylpyrrolidone, hexamethylphosphorus triamide, hexaethylphosphorus 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, and 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 generated in situ after the halogen-containing polymer is contacted with the inorganic oxide solid electrolyte, and the reaction process is as follows:

[0012]

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

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

[0015] The organic-inorganic composite solid electrolyte membrane is attached to a membrane-shaped skeleton material; the membrane-shaped skeleton material can be a dense membrane or a porous membrane, the dense membrane can be a composite membrane composed of one or several of Nafion membrane, perfluorosulfonic acid-polytetrafluoroethylene membrane, polytrifluorostyrene sulfonic acid membrane, polydifluorostyrene sulfonic 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 several of PP membrane, PE membrane, cellulose non-woven membrane, polyimide non-woven membrane, seaweed fiber non-woven membrane, aramid non-woven membrane, polyarylsulfone amide non-woven membrane, polypropylene non-woven membrane, glass fiber membrane, polyethylene terephthalate non-woven membrane.

[0016] The preparation method of the in-situ polymerized organic-inorganic composite electrolyte is characterized by in-situ polymerization and crosslinking of the unsaturated polymer on the surface of the oxide solid electrolyte; the halogen-containing polymer is mixed with the inorganic oxide solid electrolyte powder material, the Lewis base oxygen atom on the surface of the inorganic oxide solid electrolyte induces the halogen-containing polymer to lose halogen elements at a certain temperature, and an unsaturated polymer containing C=C groups is generated in-situ.

[0017] The specific reaction process is as follows:

[0018]

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

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

[0021] (1) The oxide solid electrolyte powder material, the halogen-containing polymer, and the polar organic solvent are stirred at a speed of 100-3000 r / min at room temperature for 1-72 h to obtain a suspension, and 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 on a flat plate or a membrane-shaped skeleton material by casting, flow casting, spin coating, or coating, and in-situ crosslinking polymerization is carried out in a sealed container at a temperature of 40-300 ℃ to obtain a separator, and the processing time is 1-72 h.

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

[0024] 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 is composed of a positive electrode active material, or a positive electrode active material with a polymer surface layer, a conductive agent, and a binder;

[0027] The positive electrode active material is lithium iron phosphate, lithium manganese iron phosphate, lithium cobaltate, lithium manganate, ternary material of nickel cobalt manganese, lithium nickel manganate, transition metal oxide A x MO2 (A is Na or K, M is one or more of Co, Fe, Mn, and Ni, etc.), polyanion compound A X M Y (X a O b )Z w (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 The composite positive electrode is composed of one or more of the following: lithium iron phosphate, lithium manganese iron phosphate, lithium cobaltate, lithium manganate, ternary material of nickel cobalt manganese, lithium nickel manganate, transition metal oxide A

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

[0029] The preparation method of the polymer surface layer on the surface of the positive electrode active material is as follows: a halogen-containing polymer and a positive electrode active material containing a Lewis base oxygen atom are added to a solvent, the mixture is stirred to obtain a mixture, under certain conditions, the Lewis base oxygen atom in the positive electrode active material induces the precursor to undergo a polymerization reaction to form an in-situ cross-linked polymer coating layer, and the solvent is dried to obtain a positive electrode material powder with a surface layer; the specific preparation method includes:

[0030] The positive electrode active material containing a Lewis base oxygen atom includes lithium cobaltate, lithium manganate, ternary material of nickel cobalt manganese, lithium nickel manganate, transition metal oxide A x MO2 (A is Na or K, M is one or more of Co, Fe, Mn, and Ni, etc.), polyanion compound A

[0031] The conductive agent is one or more of acetylene black, BLACK PEARLS 2000, Ketjen black, Super-P, carbon nanotubes, carbon nanofibers, activated carbon, and graphene;

[0032] The binder is one or a composite of several of butyl 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: mixing the positive active material with or without a surface layer, a conductive agent, a binder and a solvent by stirring, grinding or ball milling to prepare a slurry, coating the slurry on the surface of the current collector by casting, flow casting or spin coating or coating, and drying to obtain the positive electrode plate; the solvent used includes one or several of deionized water, ethanol, acetone, acetonitrile, cyclohexane, tetrahydrofuran, diphenyl ether, dimethyl sulfoxide, N,N-dimethylformamide, dimethylacetamide, N-methyl pyrrolidone, hexamethylphosphorus triamide, and hexaethylphosphorus triamide;

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

[0035] The solid-state battery has a solid electrolyte interlayer between the positive electrode and the organic-inorganic composite solid electrolyte film or has no interlayer;

[0036] The solid electrolyte interlayer between the positive electrode and the in-situ polymerized organic-inorganic composite solid electrolyte film 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, and a lithium salt-polymer composite solid electrolyte; the inorganic solid electrolyte includes an inorganic oxide solid electrolyte, including xA2O·yMO n (A is 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), a garnet-type inorganic solid electrolyte including 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); a 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 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 = one or several of La, Ce or Gd) and A2B 12 H 12 (A is Li, Na or K);

[0037] The polymer includes one or several of polyolefin, polyvinylidene fluoride, poly(vinylidene fluoride-hexafluoropropylene), cellulose, epoxy resin, polyacrylonitrile, polymethylethylene carbonate, polyethylene carbonate, polyimide, polyphenylene olefin, polysulfone, polyaryletherketone, polyarylethersulfone, polybenzimidazole, polybenzothiazole;

[0038] The alkali metal salt includes one or several 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 alkali metal negative electrode or alkali metal composite negative electrode;

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

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

[0042] The conductive framework material is divided into three-dimensional self-supporting material and composite framework material made of one of carbon-based material or silicon-based material and conductive agent and binder,

[0043] The three-dimensional self-supporting material includes one or several of stainless steel mesh, copper mesh, nickel mesh, nickel foam, copper foam, carbon cloth, carbon fiber felt, carbon plate, graphene, electrostatic spinning organic polymer fiber cloth.

[0044] The carbon-based material is one or more of graphite, amorphous carbon, mesocarbon microbeads, 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 vanadium-silicon alloy;

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

[0047] The preparation method of the composite framework material is as follows: carbon-based material or silicon-based material, conductive agent, binder, and solvent are mixed by stirring, grinding, or ball milling to form a slurry, the slurry is coated on the surface of a copper foil or titanium foil current collector by casting, flow casting, spin coating, or coating, and the coated product is dried to obtain a negative electrode sheet; the solvent used includes one or several of deionized water, ethanol, acetone, acetonitrile, cyclohexane, tetrahydrofuran, diphenyl ether, dimethyl sulfoxide, N,N-dimethylformamide, dimethylacetamide, N-methyl pyrrolidone, hexamethylphosphorus triamide, and hexaethylphosphorus triamide;

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

[0049] The solid-state battery has a solid electrolyte interlayer between the alkali metal negative electrode or the composite negative electrode and the in-situ polymerized organic-inorganic composite solid electrolyte membrane, or does not have an 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, or a lithium salt-polymer composite solid electrolyte;

[0050] The solid-state battery is assembled into a solid-state battery by stacking 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 can battery, or a cylindrical battery.

[0051] The composite solid electrolyte prepared by this invention exhibits a room-temperature ionic conductivity exceeding 0.1 mS / cm, an electrochemical window greater than 4.5 V, and an alkali metal cation transference number greater than 0.9. Furthermore, this composite solid electrolyte is easily deposited into a thin film. Solid-state alkali metal batteries assembled using this electrolyte film demonstrate excellent interfacial stability with both the positive and negative electrodes, and can suppress the growth of alkali metal dendrites, significantly improving battery performance.

[0052] The advantages of this invention are:

[0053] 1. The inorganic oxide solid electrolyte used in this invention has Lewis bases on its surface oxygen atoms, which are capable of conducting alkali metal cations. The strong electronegativity of the halogen atoms on the halogen-containing polymer segments enhances the acidity of the hydrogen atoms on the surrounding carbon atoms. The Lewis base oxygen atoms can induce a β-elimination reaction in the halogenated polymer at a certain temperature. Specifically, the surface oxygen atoms attack the hydrogen atoms on the adjacent carbons of the carbons connected to the halogen atoms, causing the halogenated polymer to eliminate one molecule of hydrogen halide, resulting in an unsaturated polymer containing C=C. Further cross-linking polymerization occurs at a certain temperature, forming a close contact with the inorganic oxide solid electrolyte. Meanwhile, halogen atoms have a high electron cloud density, attracting alkali metal cations from inorganic oxide solid electrolytes to accumulate on the surface. This forms a space charge layer at the interface between the organic phase and the inorganic solid electrolyte, which is more conducive to the transport of alkali metal cations. This becomes the main conduction pathway for alkali metal cations in the in-situ cross-linked polymerized organic-inorganic composite electrolyte, significantly improving the room temperature ionic conductivity of the in-situ cross-linked polymerized organic-inorganic composite electrolyte. In addition, by utilizing the reaction between halogen-containing polymers and Lewis base oxygen atoms on the cathode surface, a surface layer can be formed on the cathode material, improving battery performance.

[0054] 2. The present invention uses an inorganic oxide solid electrolyte with single-ion conductivity to prepare an in-situ polymerized organic-inorganic composite electrolyte by combining it with a polymer. Since no alkali metal cation salt is added, the in-situ cross-linked polymerized composite solid electrolyte is a single-ion conductor with the advantage of high ion transference number, which can inhibit the growth of alkali metal dendrites. Because it contains inorganic oxide solid electrolyte, the electrochemical window of the in-situ polymerized composite solid electrolyte is significantly improved compared with that of polymer electrolyte, and it has good application prospects.

[0055] 3. The in-situ polymerized organic-inorganic composite solid electrolyte prepared by this invention involves uniformly dispersing the oxide solid electrolyte in a composite solid electrolyte slurry. The polymer phase exhibits flexibility, enhancing the processing performance of the composite solid electrolyte. The resulting composite solid electrolyte is easy to fabricate into large-area films, effectively reducing membrane impedance. Furthermore, the in-situ crosslinking polymerization of the organic-inorganic composite solid electrolyte provides flexibility and facilitates good interfacial contact with the positive and negative electrodes. These advantages endow the organic-inorganic composite solid electrolyte membrane with rapid alkali metal ion conduction, excellent interfacial stability with the positive and negative electrodes, dendrite growth inhibition, and oxidation resistance, significantly improving battery safety and cycle life.

[0056] 4. This invention uses a composite solid electrolyte produced by in-situ polymerization of a single-ion conductor to prepare solid-state batteries. The preparation method is compatible with existing lithium-ion battery equipment and processes. It can be used to prepare almost all types of batteries through various assembly methods, including stacking and winding, including: button cells, pouch cells, prismatic cells, and cylindrical cells. Attached Figure Description

[0057] Figure 1 The image shows a SEM image of LAGP after being composited with polyvinylidene fluoride (PVDF) in Comparative Example 1. As can be seen from the image, LAGP composited with PVDF cannot be uniformly dispersed in the composite electrolyte, and cracks are observed on the surface. This is because the oxygen atoms in the LAGP oxide solid electrolyte are located in the phosphate groups and do not contain oxygen atoms that are Lewis bases. Therefore, PVDF cannot undergo in-situ polymerization on the LAGP surface to achieve a tight bond between LAGP and PVDF.

[0058] Figure 2 The image shows a TEM image of LLZTO after being composited with perfluoroethylene in Comparative Example 2. As can be seen from the image, no amorphous layered structure can be observed on the surface of LLZTO after being composited with perfluoroethylene. This indicates that because perfluoroethylene does not contain hydrogen atoms that provide acidity, it cannot react with the oxygen atoms, which are Lewis bases, on the surface of the oxide solid electrolyte LLZTO, and thus no polymer surface layer is formed on the LLZTO surface.

[0059] Figure 3 This is a SEM image of the composite electrolyte PVDF-LLZTO after reaction with the polymer precursor polyvinylidene fluoride in Example 1.

[0060] Figure 4This is a TEM image of the PVDF-LLZTO composite electrolyte after reaction with the polymer precursor polyvinylidene fluoride (PVDF) in Example 1. As can be seen from the image, the LLZTO particles after reaction with PVDF are uniformly dispersed in the composite electrolyte, and their surfaces have a uniform amorphous surface layer. This indicates that under the inductive effect of LLZTO, PVDF generates an in-situ cross-linked surface layer on the surface of LLZTO, thus altering the surface structure of LLZTO.

[0061] Figure 5 The image shows a Raman comparison of the composite electrolyte PVDF-LLZTO, which reacted with the polymer precursor polyvinylidene fluoride in Example 1, and the composite electrolyte LAGP and polyvinylidene fluoride in Comparative Example 1. Compared to the PVDF-LAGP sample, a C=C bond peak was observed in PVDF-LLZTO, indicating that under the induction of LLZTO, polyvinylidene fluoride underwent a defluorination reaction on the surface of LLZTO, further resulting in crosslinking.

[0062] Figure 6 The figures show the polarization voltage-time curves of Li-Li symmetric cells assembled from the poly(perfluoroethylene)-LLZTO composite solid electrolyte membrane in Comparative Example 2 and the PVDF-LLZTO composite electrolyte in Example 1, respectively. As shown in the figures, the composite electrolyte membrane prepared by combining LLZTO and PVDF significantly improves the cycle stability of the lithium anode, with a cycle life >2000 h.

[0063] Figure 7 The graph shows a comparison of cycle-specific capacity between the batteries assembled with the PVDF-LAGP composite solid electrolyte membrane in Comparative Example 1 and the PVDF-LLZTO batteries in Example 1. As shown in the graph, the PVDF-LLZTO composite electrolyte membrane improves the specific capacity and cycle stability (150 mAh / g; capacity retention of ~90% after 450 cycles) of the LFP / Li lithium battery. Example

[0064] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended 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 aluminum germanium phosphate (LAGP) powder were added to 10 g of acetonitrile. The mixture was stirred at 100 r / min for 4 h at room temperature to obtain a suspension, thus preparing an organic-inorganic composite solid electrolyte slurry. The slurry was coated onto a cellulose membrane using a coating method, and then crosslinked and polymerized in a sealed container at 100℃ for 24 h to obtain the organic-inorganic composite solid electrolyte membrane. This membrane was cut into discs with a diameter of 19 mm and a thickness of 40 μm. Electrochemical tests showed that the composite solid electrolyte had a room temperature ionic conductivity of 0.01 mS / cm, an electrochemical window of 4.0 V, and a lithium-ion transference number of 0.75. The positive electrode was prepared as follows: 80 mg LFP positive electrode powder, 9 mg PVDF binder, 1 mg polyvinylidene fluoride-LAGP composite solid electrolyte slurry, and 10 mg Super P conductive agent were uniformly dispersed in 100 mg NMP solvent. After grinding in a mortar for 1 hour, the mixture was coated onto aluminum foil and vacuum dried at 100°C for 24 hours to obtain the LFP positive electrode, which was then cut into 10 mm diameter discs for later use. The solid electrolyte coating layer on the positive electrode surface was prepared as follows: 1 g of polyvinylidene fluoride-LAGP composite solid electrolyte was uniformly dispersed in 9 g of NMP solvent and stirred at 1500 r / min at 45°C for 12 hours to obtain a uniform slurry. The prepared slurry was coated onto the positive electrode using a coating method and then dried under vacuum at 100°C for 24 hours. Finally, a 2016-type button battery was assembled using LFP coated with solid electrolyte as the positive electrode, lithium metal as the negative electrode, and the solid electrolyte composite membrane as the electrolyte. The cycle performance at 1C rate rapidly declined.

[0067] Comparative Example 2:

[0068] In this comparative example, 0.6 g of perfluoroethylene and 1.2 g of LLZTO powder were added to 10 g of ethanol, and the mixture was magnetically stirred at 1500 r / min for 1 h at room temperature to prepare an organic-inorganic composite solid electrolyte slurry. The slurry was coated onto a cellulose membrane using a coating method, and then crosslinked polymerized at a certain temperature in a sealed container at 100°C for 24 h to obtain the organic-inorganic composite solid electrolyte membrane. This membrane was cut into 19 mm diameter discs for later use, and 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, significantly lower than the 0.1 mS / cm of the composite solid electrolyte in the examples. The electrochemical window was 4.0 V, significantly lower than the electrochemical window of the composite solid electrolyte in the examples. The lithium-ion transference number was 0.75, significantly lower than the lithium-ion transference number of the composite solid electrolyte in the examples. The positive electrode sheet was prepared as follows: 80 mg LFP positive electrode powder, 9 mg PVDF binder, 1 mg polytetrafluoroethylene-LLZTO composite solid electrolyte slurry, and 10 mg Super P conductive agent were uniformly dispersed in 100 mg NMP solvent. After grinding in a mortar for 1 hour, the mixture was coated onto aluminum foil and vacuum dried at 100°C for 24 hours to obtain the LFP positive electrode sheet, which was then cut into 10 mm diameter discs for later use. The solid electrolyte coating layer on the positive electrode surface was prepared as follows: 1 g of polytetrafluoroethylene-LLZTO composite solid electrolyte was uniformly dispersed in 9 g NMP solvent and stirred at 1500 r / min for 12 hours at 45°C to obtain a uniform slurry. The prepared slurry was coated onto the positive electrode using a coating method and then dried under vacuum at 100°C for 24 hours. Finally, using LFP coated with solid electrolyte as the positive electrode, lithium metal as the negative electrode, and a solid electrolyte composite membrane as the electrolyte, a 2016-type button cell was assembled. After 53 cycles at 1C rate, the capacity retention rate was less than 80%.

[0069] Comparative Example 3:

[0070] In this embodiment, 0.5g of poly(ethylene fluoride) propylene oxide and 1g of lithium nitride powder were added to 10g of dimethyl sulfoxide and stirred at 1500 rpm for 12 hours at room temperature to obtain an organic-inorganic composite solid electrolyte slurry. The slurry was then cast onto a polyimide nonwoven membrane using a casting method and subjected to crosslinking polymerization at a specific temperature. The conditions were 300℃ in a sealed container for 1 hour to obtain an organic-inorganic composite solid electrolyte membrane with a thickness of 100 μm, which was cut into 19 mm diameter discs for later use. Electrochemical tests showed that the room temperature ionic conductivity of the composite solid electrolyte was 0.12 mS / cm, the electrochemical window reached 4.6 V, and the lithium-ion transference number was 0.9. The positive electrode sheet was prepared as follows: 80 mg of lithium nickel manganese oxide positive electrode powder, 10 mg of PVDF binder, and 10 mg of Ketjen black conductive agent were uniformly dispersed in NMP solvent. After grinding in a mortar for 1 hour, the mixture was coated onto aluminum foil and vacuum dried at 100°C for 24 hours to obtain a lithium nickel manganese oxide positive electrode sheet, which was then cut into 10 mm diameter discs for later use. The solid electrolyte coating layer on the positive electrode surface was prepared as follows: 1 g of polybenzimidazole-lithium nitride composite solid electrolyte powder was uniformly dispersed in 4 g of N-methylpyrrolidone solvent. The mixture was stirred at 300°C and 3000 r / min for 1 hour to prepare a uniform slurry. This slurry was then coated onto the positive electrode and dried under vacuum at 100°C for 24 hours. Finally, using lithium nickel manganese oxide coated with solid electrolyte as the positive electrode, lithium metal as the negative electrode, and the solid electrolyte composite membrane as the electrolyte, a 2016-type button battery was assembled. At 1C rate, the capacity retention rate after 100 cycles was less than 50%.

[0071] Comparative Example 4:

[0072] In this embodiment, 2g of poly(tetrafluoroethylene-ethylene) and 1g of LATP powder were added to 10g of N,N-dimethylformamide, and the mixture was magnetically stirred at 1500 rpm for 5 hours at room temperature to obtain an organic-inorganic composite solid electrolyte slurry. The slurry was then coated onto an aramid nonwoven membrane using a casting method and kept in a sealed container at 40°C for 72 hours to obtain the organic-inorganic composite solid electrolyte membrane. The composite solid electrolyte membrane had a thickness of 200 μm and was cut into discs with a diameter of 19 mm for later use. Electrochemical tests showed that the room temperature ionic conductivity of the composite solid electrolyte was 0.14 mS / cm, the electrochemical window reached 4.6 V, and the lithium-ion transference number was 0.91. The positive electrode sheet was prepared as follows: 80 mg of lithium cobalt oxide positive electrode powder, 8 mg of PVDF binder, 2 mg of poly(tetrafluoroethylene-ethylene)-LATP composite solid electrolyte powder, and 10 mg of BLACK PEARLS 2000 conductive agent were uniformly dispersed in NMP solvent, ground in a mortar for 1 hour, coated onto nickel foam, and vacuum dried at 100°C for 24 hours to obtain the lithium cobalt oxide positive electrode sheet. The solid electrolyte coating layer on the positive electrode surface was prepared as follows: 1 g of polybenzothiazole-LATP composite solid electrolyte powder was uniformly dispersed in 9 g of NMP solvent, stirred at 100 r / min and 45°C for 72 hours to obtain a uniform slurry, which was then coated onto the positive electrode and dried under vacuum at 100°C for 24 hours. The negative electrode sheet was prepared 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 hour, coated onto nickel foam, and vacuum dried at 100°C for 24 hours. It was then cut into 10 mm diameter discs for later use. A composite negative electrode was then prepared using a melt method: lithium metal was heated to 180°C to melt, and the negative electrode sheet was immersed in the molten lithium metal and allowed to cool to room temperature. Finally, a soft-pack battery was assembled using lithium cobalt oxide coated with a solid electrolyte as the positive electrode, graphite as the negative electrode, and a solid electrolyte composite membrane as the electrolyte. However, it could not cycle effectively at a 1C rate.

[0073] Comparative Example 5:

[0074] In this embodiment, 3g of polytrifluoroethylene and 0.2g of lithium indium chloride (Li3InCl6) powder were added to 10g of dimethylacetamide, and stirred at a constant speed of 1600 rpm for 4 hours at room temperature to obtain an organic-inorganic composite solid electrolyte slurry. The slurry was then spin-coated onto a polypropylene nonwoven membrane at 600 rpm and kept in a sealed container at 120°C for 18 hours to obtain an organic-inorganic composite solid electrolyte membrane with a thickness of 50 μm. This membrane was then cut into discs with a diameter of 19 mm for later use. Electrochemical tests showed that the composite solid electrolyte had a room temperature ionic conductivity of 0.15 mS / cm, an electrochemical window of 4.55 V, and a lithium-ion transference number of 0.95. The positive electrode was prepared as follows: 80 mg of NCM622 positive electrode powder, 7 mg of PVDF binder, 3 mg of polytrifluoroethylene-Li3InCl6 composite solid electrolyte powder, and 10 mg of acetylene black conductive agent were uniformly dispersed in NMP solvent. After grinding in a mortar for 1 hour, the mixture was coated onto carbon-coated aluminum foil and vacuum dried at 120°C for 24 hours to obtain the NCM622 positive electrode, which was then cut into 10 mm diameter discs for later use. The solid electrolyte coating layer on the positive electrode surface was prepared by magnetron sputtering to form an LLZO coating with a thickness of 200 nm on the surface of the positive electrode. The negative electrode was prepared 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. After grinding in a mortar for 1 hour, the mixture was coated onto copper foil and vacuum dried at 120°C for 24 hours to obtain the hard carbon electrode, which was then cut into 10 mm diameter discs for later use. Subsequently, a lithium-containing composite anode was prepared using an electrochemical method, and a constant current method was employed at 0.1 mA / cm². -2 Discharged to a current density of 0.001V, a hard carbon composite negative electrode was obtained. Finally, a 2016-type button cell was assembled using an NCM622 positive electrode with a solid electrolyte coating, a hard carbon negative electrode, and a solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 94% after 300 cycles at 1C rate.

[0075] Example 1:

[0076] In this embodiment, 0.5 g of polyvinylidene fluoride (PVDF) and 1 g of lithium lanthanum zirconium tantalum oxide (LLZTO) powder were added to 10 g of tetrahydrofuran, and stirred at 100 r / min for 72 h at room temperature to prepare an organic-inorganic composite solid electrolyte slurry. The slurry was coated onto a cellulose membrane using a coating method, and then crosslinked polymerized at a certain temperature under the conditions of maintaining the mixture in a sealed container at 100 °C for 24 h, resulting in an organic-inorganic composite solid electrolyte membrane. This membrane was cut into discs with a diameter of 19 mm and a thickness of 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 by combining LLZTO powder without PVDF with a cellulose membrane served as a control group. The positive electrode sheet was prepared as follows: 80 mg LFP positive electrode powder, 9 mg PVDF binder, 1 mg polyvinylidene fluoride-LLZTO composite solid electrolyte slurry, and 10 mg Super P conductive agent were uniformly dispersed in 100 mg NMP solvent. After grinding in a mortar for 1 hour, the mixture was coated onto aluminum foil and vacuum dried at 100°C for 24 hours to obtain the LFP positive electrode sheet, which was then cut into 10 mm diameter discs for later use. The solid electrolyte coating layer on the positive electrode surface was prepared as follows: 1 g of polyvinylidene fluoride-LLZTO composite solid electrolyte was uniformly dispersed in 9 g NMP solvent and stirred at 1500 r / min for 12 hours at 45°C to obtain a uniform slurry. The prepared slurry was coated onto the positive electrode using a coating method and then dried under vacuum at 100°C for 24 hours. Finally, using LFP coated with solid electrolyte as the positive electrode, lithium metal as the negative electrode, and a solid electrolyte composite membrane as the electrolyte, a 2016-type button cell was assembled, with a capacity retention of ~90% after 450 cycles at 1C rate.

[0077] Example 2:

[0078] In this embodiment, 0.1 g of poly(vinylidene fluoride-hexafluoropropylene) and 1 g of lithium lanthanum titanium oxide (LLTO) powder were mixed in 5 g of diphenyl ether and stirred at a constant speed of 3000 r / min for 1 h at room temperature to prepare an organic-inorganic composite solid electrolyte slurry. The slurry was coated onto a cellulose membrane using a coating method and crosslinked polymerized at a certain temperature in a sealed container at 100°C for 24 h to obtain the organic-inorganic composite solid electrolyte membrane. The membrane was cut into discs with a diameter of 19 mm and a thickness of 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 without the poly(vinylidene fluoride-hexafluoropropylene) powder served as a control group. The preparation method of the positive electrode sheet is as follows: 210 mg of NCM622 positive electrode powder with a surface layer of poly(vinylidene fluoride-hexafluoropropylene) precursor, 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 are uniformly dispersed in NMP solvent. After magnetic stirring for 4 h, the mixture is coated onto aluminum foil and vacuum dried at 120 °C for 24 h to obtain the NCM622 positive electrode sheet, which is then cut into 10 mm diameter discs for later use. The preparation method of the polymer surface layer on the surface of the positive electrode active material is as follows: 0.5 g of poly(vinylidene fluoride-hexafluoropropylene) and 0.5 g of NCM622 powder are mixed in 2 g of NMP and magnetically stirred at 1500 r / min for 4 h at room temperature to obtain a suspension. The obtained suspension was then stirred uniformly at 3000 r / min for 72 h at 45 °C to allow poly(vinylidene fluoride-hexafluoropropylene) to polymerize on the surface of NCM622 powder, thus obtaining an NCM622 suspension containing a surface layer. The suspension was then dried in a vacuum oven at 40 °C for 72 h to obtain NCM622 powder material with a surface layer containing poly(vinylidene fluoride-hexafluoropropylene) as the precursor. The preparation method for 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 1500 r / min for 12 h at 45 °C to obtain a uniform slurry. The obtained slurry was coated onto the positive electrode and then dried under vacuum at 100 °C for 24 h. Finally, a 2032-type button cell was assembled using NCM622 coated with solid electrolyte as the positive electrode, lithium metal as the negative electrode, and a solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 84.94% after 300 cycles at 1C rate.

[0079] Example 3:

[0080] In this embodiment, 0.5 g of poly(ethylene propylene fluoride) and 1 g of lithium lanthanum zirconium oxide (LLZO) powder were added to 10 g of dimethyl sulfoxide and stirred at 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 nonwoven membrane using a casting method and then crosslinked polymerized at a certain temperature (300°C in a sealed container for 1 h) to obtain an organic-inorganic composite solid electrolyte membrane with a thickness of 100 μm. The membrane was cut into 19 mm diameter discs for later use. Electrochemical tests showed that the room temperature ionic conductivity of the composite solid electrolyte was 0.12 mS / cm, the electrochemical window reached 4.6 V, and the lithium-ion transference number was 0.9. A composite membrane prepared from LLZO powder without poly(ethylene propylene fluoride) and polyimide nonwoven membrane served as a control group. The positive electrode sheet was prepared as follows: 80 mg of lithium nickel manganese oxide positive electrode powder, 10 mg of PVDF binder, and 10 mg of Ketjen black conductive agent were uniformly dispersed in NMP solvent. After grinding in a mortar for 1 hour, the mixture was coated onto aluminum foil and vacuum dried at 100°C for 24 hours to obtain a lithium nickel manganese oxide positive electrode sheet, which was then cut into 10 mm diameter discs for later use. The solid electrolyte coating layer on the positive electrode surface was prepared as follows: 1 g of polybenzimidazole-LLZO composite solid electrolyte powder was uniformly dispersed in 4 g of N-methylpyrrolidone solvent. The mixture was stirred at 300°C and 3000 r / min for 1 hour to prepare a uniform slurry. This slurry was then coated onto the positive electrode and dried under vacuum at 100°C for 24 hours. Finally, using lithium nickel manganese oxide coated with solid electrolyte as the positive electrode, lithium metal as the negative electrode, and the solid electrolyte composite membrane as the electrolyte, a 2016-type button battery was assembled. At 1C rate, the capacity retention rate was 87% after 300 cycles.

[0081] Example 4:

[0082] In this embodiment, 2g of poly(tetrafluoroethylene-ethylene) and 1g of Li3OCl powder were added to 10g of N,N-dimethylformamide, and the mixture was magnetically stirred at 1500 rpm for 5 hours at room temperature to obtain an organic-inorganic composite solid electrolyte slurry. The slurry was then coated onto an aramid nonwoven membrane using a casting method and kept in a sealed container at 40°C for 72 hours to obtain the organic-inorganic composite solid electrolyte membrane. The composite solid electrolyte membrane had a thickness of 200 μm and was cut into discs with a diameter of 19 mm for later use. Electrochemical tests showed that the room temperature ionic conductivity of the composite solid electrolyte was 0.14 mS / cm, the electrochemical window reached 4.6 V, and the lithium-ion transference number was 0.91. A composite membrane prepared by combining Li3OCl powder without poly(tetrafluoroethylene-ethylene) with an aramid nonwoven membrane served as a control group. The positive electrode sheet was prepared as follows: 80 mg of lithium cobalt oxide positive electrode powder, 8 mg of PVDF binder, 2 mg of poly(tetrafluoroethylene-ethylene)-Li3OCl composite solid electrolyte powder, and 10 mg of BLACK PEARLS2000 conductive agent were uniformly dispersed in NMP solvent, ground in a mortar for 1 hour, coated onto nickel foam, and vacuum dried at 100°C for 24 hours to obtain the lithium cobalt oxide positive electrode sheet. The solid electrolyte coating layer on the positive electrode surface was prepared as follows: 1 g of polybenzothiazole-Li3OCl composite solid electrolyte powder was uniformly dispersed in 9 g of NMP solvent, stirred at 100 r / min and 45°C for 72 hours to obtain a uniform slurry, which was then coated onto the positive electrode and dried under vacuum at 100°C for 24 hours. The negative electrode sheet was prepared 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 hour, coated onto nickel foam, and vacuum dried at 100°C for 24 hours. It was then cut into 10 mm diameter discs for later use. A composite negative electrode was then prepared using a melt method: lithium metal was heated to 180°C to melt, and the negative electrode sheet was immersed in the molten lithium metal and allowed to cool to room temperature. Finally, a pouch cell was assembled using lithium cobalt oxide coated with a solid electrolyte as the positive electrode, graphite as the negative electrode, and a solid electrolyte composite membrane as the electrolyte. At 1C rate, the capacity retention rate was 80% after 50 cycles.

[0083] Example 5:

[0084] In this embodiment, 3g of polytrifluoroethylene (PTFE) and 0.2g of Li₂O·SiO₂ powder were added to 10g of dimethylacetamide and stirred at 1600 rpm for 4 hours at room temperature to prepare an organic-inorganic composite solid electrolyte slurry. The slurry was then spin-coated onto a polypropylene nonwoven membrane at 600 rpm and kept in a sealed container at 120°C for 18 hours to obtain an organic-inorganic composite solid electrolyte membrane with a thickness of 50 μm. This membrane was then cut into 19 mm diameter discs for later use. Electrochemical tests showed that the composite solid electrolyte had a room temperature ionic conductivity of 0.15 mS / cm, an electrochemical window of 4.55 V, and a lithium-ion transference number of 0.95. A composite membrane prepared by combining Li₂O·SiO₂ powder without PTFE with a polypropylene nonwoven membrane served as a control group. The positive electrode was prepared as follows: 80 mg of NCM622 positive electrode powder, 7 mg of PVDF binder, 3 mg of polytrifluoroethylene-Li2O·SiO2 composite solid electrolyte powder, and 10 mg of acetylene black conductive agent were uniformly dispersed in NMP solvent. After grinding in a mortar for 1 hour, the powder was coated onto carbon-coated aluminum foil and vacuum dried at 120°C for 24 hours to obtain the NCM622 positive electrode, which was then cut into 10 mm diameter discs for later use. The solid electrolyte coating layer on the positive electrode surface was prepared by magnetron sputtering to form an LLZO coating with a thickness of 200 nm on the surface of the positive electrode. The negative electrode was prepared 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. After grinding in a mortar for 1 hour, the powder was coated onto copper foil and vacuum dried at 120°C for 24 hours to obtain the hard carbon electrode, which was then cut into 10 mm diameter discs for later use. Subsequently, a lithium-containing composite anode was prepared using an electrochemical method, and a constant current method was employed at 0.1 mA / cm². -2 Discharged to a current density of 0.001V, a hard carbon composite negative electrode was obtained. Finally, a 2016-type button cell was assembled using an NCM622 positive electrode with a solid electrolyte coating, a hard carbon negative electrode, and a solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 94% after 300 cycles at 1C rate.

[0085] Example 6:

[0086] In this embodiment, 0.5g of polyvinyl fluoride (PVC) and 1g of sodium lanthanum zirconium tantalum oxide (SLAM) powder were added to 10g of N-methylpyrrolidone (N-Methylpyrrolidone) and stirred at a constant speed of 1200 rpm for 4 hours at room temperature to prepare an organic-inorganic composite solid electrolyte slurry. The slurry was coated onto a cellulose membrane using a coating method and crosslinked polymerized at a certain temperature in a sealed container at 100°C for 24 hours to obtain the organic-inorganic composite solid electrolyte membrane. The membrane was then cut into 19mm diameter discs for later use, with a thickness of 40μm. Electrochemical tests showed that the room temperature ionic conductivity of the composite solid electrolyte was 0.13 mS / cm, the electrochemical window reached 4.7V, and the sodium ion transference number was 0.93. A solid electrolyte membrane prepared from sodium lanthanum zirconium tantalum oxide powder without PVC composite was used as a control group. The positive electrode sheet was prepared 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 uniformly dispersed in NMP solvent. After grinding in a mortar for 1 hour, the mixture was coated onto aluminum foil and vacuum dried at 100°C for 24 hours to obtain the sodium vanadium phosphate positive electrode sheet, which was then cut into 10 mm diameter discs for later use. The solid electrolyte coating layer on the positive electrode surface was prepared as follows: 1 g of polyvinyl fluoride-sodium lanthanum zirconium tantalum oxide composite solid electrolyte powder was uniformly dispersed in 9 g of NMP solvent and stirred at 1500 r / min for 12 hours at 80°C to obtain a uniform slurry. This slurry was then coated onto the positive electrode and dried under vacuum at 100°C for 24 hours. Finally, using 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, a 2016-type button battery was assembled. At 1C rate, the capacity retention rate was 89.4% after 300 cycles.

[0087] Example 7:

[0088] In this embodiment, 0.1 g of polyethylene trifluoroethylene and 1 g of sodium lanthanum titanium oxide powder were mixed in 5 g of hexamethylphosphoric triamine and stirred at a constant speed of 2500 r / min for 4 h at room temperature to prepare an organic-inorganic composite solid electrolyte slurry. The slurry was coated onto a cellulose membrane using a coating method and crosslinked polymerized at a certain temperature in a sealed container at 100°C for 24 h to obtain the organic-inorganic composite solid electrolyte membrane. The membrane was cut into discs with a diameter of 19 mm and a thickness of 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 without the polyethylene trifluoroethylene composite served as a control group. The positive electrode sheet was prepared 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 hours, the mixture was coated onto aluminum foil and vacuum dried at 120°C for 24 hours to obtain the Prussian blue positive electrode sheet, which was then cut into 10 mm diameter discs for later use. Finally, a 2032-type button cell was assembled using Prussian blue positive electrode, metallic sodium as negative electrode, and a solid electrolyte composite membrane as electrolyte. The capacity retention rate was 83% after 300 cycles at 1C rate.

[0089] Example 8:

[0090] In this embodiment, 0.5g of polyvinylidene chloride (PVDC) and 1g of Na2O·Al2O3 powder were added to 10g of hexaethylphosphoric triamine. The mixture was stirred at 150 rpm for 4 hours at room temperature to obtain an organic-inorganic composite solid electrolyte slurry. The slurry was coated onto a glass plate using a doctor blade and crosslinked polymerized at a certain temperature in a sealed container at 300°C for 1 hour to obtain an organic-inorganic composite solid electrolyte membrane. The composite solid electrolyte membrane had a thickness of 100 μm and was cut into discs with a diameter of 19 mm for later use. Electrochemical tests showed that the room temperature ionic conductivity of the composite solid electrolyte was 0.15 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 without PVDC was used as a control group. The positive electrode is prepared 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 Ketjen black conductive agent are uniformly dispersed in NMP solvent. After grinding in a mortar for 1 hour, the mixture is coated onto aluminum foil and vacuum dried at 100°C for 24 hours to obtain the positive electrode. The positive electrode is then cut into 10 mm diameter discs for later use. The solid electrolyte coating layer on the positive electrode surface is prepared as follows: the prepared polyvinylidene chloride-Na2O·Al2O3 composite solid electrolyte slurry is coated onto the positive electrode and then dried under vacuum at 100°C for 24 hours. The negative electrode is prepared as follows: 80 mg of hard carbon powder, 10 mg of PVDF binder, and 10 mg of acetylene black conductive agent are uniformly dispersed in NMP solvent. After grinding in a mortar for 1 hour, the mixture is coated onto copper foil and vacuum dried at 120°C for 24 hours to obtain the hard carbon negative electrode. Hard carbon-sodium metal composite negative electrodes were prepared by roll forming at 300℃ and 20MPa, and cut into 10mm diameter discs for later use. Finally, a 2016-type button cell was assembled using a polyanion-type positive electrode coated with solid electrolyte, a hard carbon negative electrode, and a solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 87% after 300 cycles at 1C rate.

[0091] Example 9:

[0092] In this embodiment, 2g of poly(vinylidene chloride-hexachloropropylene) and 1g of K3OCl powder were added to 10g of triethyl phosphate, and stirred at a constant speed of 1500 rpm for 24 hours at room temperature to prepare an organic-inorganic composite solid electrolyte slurry. The slurry was then cast onto a polytetrafluoroethylene plate using a casting method and kept in a sealed container at 40°C for 72 hours to obtain an organic-inorganic composite solid electrolyte membrane. The composite solid electrolyte membrane had a thickness of 200 μm and was cut into circular pieces with a diameter of 19 mm for later use. Electrochemical tests showed that the room temperature ionic conductivity of the composite solid electrolyte was 0.1 mS / cm, the electrochemical window reached 4.5 V, and the potassium ion transference number was 0.9. A solid electrolyte membrane prepared without the poly(vinylidene chloride-hexachloropropylene) composite K3OCl powder served as a control group. The positive electrode sheet is prepared 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 are uniformly dispersed in NMP solvent. After grinding in a mortar for 1 hour, the mixture is coated onto nickel foam and vacuum dried at 100°C for 24 hours to obtain the positive electrode sheet. The solid electrolyte coating layer on the positive electrode surface is prepared as follows: 1 g of organic-inorganic composite solid electrolyte is uniformly dispersed in 9 g of NMP solvent. The mixture is stirred at 100 r / min at 45°C for 72 hours to obtain a uniform slurry. This slurry is then coated onto the positive electrode and dried under vacuum at 100°C for 24 hours. The negative electrode sheet was prepared 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 hour, and then coated onto nickel foam and vacuum dried at 100°C for 24 hours to obtain the negative electrode sheet. Finally, a pouch cell was assembled using a nickel-cobalt-manganese ternary electrode coated with a solid electrolyte as the positive electrode, silicon as the negative electrode, and a solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 88% after 30 cycles at 1C rate.

[0093] Example 10:

[0094] In this embodiment, 3g of polyethylene propylene chloride and 0.2g of K₂O·SiO₂ powder were added to 20g of trimethyl phosphate, and stirred at 1500 rpm for 4 hours at room temperature to obtain an organic-inorganic composite solid electrolyte slurry. The slurry was coated onto a polypropylene nonwoven membrane using a doctor blade and crosslinked polymerized at a certain temperature in a sealed container at 120°C for 18 hours to obtain an organic-inorganic composite solid electrolyte membrane. The composite solid electrolyte membrane had a thickness of 40 μm and was cut into 19 mm diameter discs for later use. Electrochemical tests showed that the room temperature ionic conductivity of the composite solid electrolyte was 0.12 mS / cm, the electrochemical window reached 4.5 V, and the potassium ion transference number was 0.9. A composite membrane prepared by combining K₂O·SiO₂ powder without polyethylene propylene chloride with a polypropylene nonwoven membrane served as a control group. The positive electrode sheet was prepared as follows: 85 mg of Prussian blue positive electrode powder, 7 mg of PVDF binder, 3 mg of polyethylene propylene chloride-K2O·SiO2 electrolyte slurry, and 10 mg of acetylene black conductive agent were uniformly dispersed in NMP solvent. After grinding in a mortar for 1 hour, the mixture was coated onto carbon-coated aluminum foil and vacuum dried at 120°C for 24 hours to obtain the Prussian blue positive electrode sheet, which was then cut into 10 mm diameter discs for later use. The solid electrolyte coating layer on the positive electrode surface was prepared as follows: 1 g of polyethylene carbonate-K2O·SiO2 composite solid electrolyte powder was uniformly dispersed in 9 g of NMP solvent and stirred at 1500 r / min at 120°C for 12 hours to obtain a uniform slurry. This slurry was then coated onto the positive electrode and dried under vacuum at 100°C for 24 hours. Finally, a 2016-type button cell was assembled using a Prussian blue positive electrode coated with solid electrolyte, a potassium metal negative electrode, and a solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 94% after 300 cycles at 1C rate.

[0095] Example 11:

[0096] In this embodiment, 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 stirred at a constant speed of 1500 r / min for 4 h at room temperature to prepare an organic-inorganic composite solid electrolyte slurry. The slurry was coated onto a glass fiber membrane using a coating method, and then crosslinked polymerized at a certain temperature under the conditions of maintaining the mixture in a sealed container at 100°C for 24 h, resulting in an organic-inorganic composite solid electrolyte membrane. This membrane was then cut into discs with a diameter of 19 mm for later use. 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 by combining LLZTO powder without poly(tetrachloroethylene-ethylene) with a glass fiber membrane served as a control group. The preparation method of the positive electrode sheet is as follows: 80 mg of lithium manganese oxide positive electrode powder with a surface layer of poly(tetrachloroethylene-ethylene) precursor, 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 are uniformly dispersed in 100 mg of NMP solvent. After grinding in a mortar for 1 hour, the mixture is coated onto aluminum foil and vacuum dried at 100°C for 24 hours to obtain the lithium manganese oxide positive electrode sheet, which is then cut into 10 mm diameter discs for later use. The preparation method of the polymer surface layer on the surface of the positive electrode active material is as follows: 0.5 g of poly(tetrachloroethylene-ethylene) and 0.5 g of lithium manganese oxide powder are mixed in 2 g of NMP and stirred at a constant speed of 1500 r / min for 4 hours at room temperature to obtain a suspension. The obtained suspension was stirred uniformly at 3000 r / min for 72 h at 45 °C to polymerize poly(tetrachloroethylene-ethylene) on the surface of lithium manganese oxide powder, thus obtaining a lithium manganese oxide suspension containing a surface layer. The suspension was then dried in a vacuum oven at 40 °C for 72 h to obtain lithium manganese oxide powder material with a surface layer of poly(tetrachloroethylene-ethylene) precursor. 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 1500 r / min for 12 h at 45 °C to obtain a uniform slurry. The obtained slurry was coated onto the positive electrode and then dried under vacuum at 100 °C for 24 h. The preparation method of the solid electrolyte coating layer on the negative electrode surface is as follows: 1g of poly(vinylidene fluoride-hexafluoropropylene)-LiTFSI-LLZO (mass ratio 1:1:1) composite solid electrolyte is uniformly dispersed in 9g of NMP solvent, and stirred at 1500r / min for 12h at 45℃ to obtain a uniform slurry. The prepared slurry is coated onto the lithium negative electrode and then dried under vacuum at 100℃ for 24h.Finally, a 2016-type button cell was assembled using lithium manganese oxide coated with solid electrolyte as the positive electrode, lithium metal as the negative electrode, and a solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 85% after 300 cycles at 1C rate.

[0097] Example 12:

[0098] In this embodiment, 0.1 g of polyvinyl chloride (PVC) and 1 g of lithium lanthanum titanium oxide (LLTO) powder were mixed in 4 g of fluoropropylene carbonate and stirred at a constant speed of 1500 r / min for 4 h at room temperature to prepare an organic-inorganic composite solid electrolyte slurry. The slurry was coated onto a cellulose membrane using a coating method and then crosslinked polymerized at a certain temperature in a sealed container at 100°C for 24 h to obtain the organic-inorganic composite solid electrolyte membrane. The membrane was cut into discs with a diameter of 19 mm and a thickness of 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 without LLTO powder composited with PVC served as a control group. The preparation method of the positive electrode sheet is as follows: 210 mg of NCM811 positive electrode powder with a polyvinyl chloride (PVC) precursor surface layer, 2.5 mg of polytetrafluoroethylene (PTFE) binder, 25 mg of PVC-LLTO composite solid electrolyte slurry, and 25 mg of carbon nanofiber conductive agent are uniformly dispersed in NMP solvent. After magnetic stirring for 4 hours, the mixture is coated onto aluminum foil and vacuum dried at 120°C for 24 hours to obtain the NCM811 positive electrode sheet, which is then cut into 10 mm diameter discs for later use. The preparation method of the polymer surface layer on the surface of the positive electrode active material is as follows: 0.5 g of PVC and 0.5 g of NCM811 powder are mixed in 2 g of NMP and stirred at 1500 r / min for 4 hours at room temperature to obtain a suspension. The resulting mixture suspension is stirred uniformly at 3000 r / min at 45°C for 72 hours to allow PVC to polymerize on the surface of the NCM811 powder, thus obtaining an NCM811 suspension containing the surface layer. The suspension was dried in a vacuum oven at 40°C for 72 hours to obtain NCM811 powder material with a polyvinyl chloride precursor surface layer. The solid electrolyte coating layer on the positive electrode surface was prepared as follows: 1g of cellulose-LiBOB-LiBH4 (mass ratio 1:1:1) composite solid electrolyte was uniformly dispersed in 9g of NMP solvent and stirred at 1500r / min for 12 hours at 45°C to obtain a uniform slurry. The prepared slurry was coated onto the positive electrode and then dried under vacuum at 100°C for 24 hours. The solid electrolyte coating layer on the negative electrode surface was prepared as follows: 1g of cellulose-LiBOB-LiBH4 (mass ratio 1:1:1) composite solid electrolyte was uniformly dispersed in 9g of NMP solvent and stirred at 1500r / min for 12 hours at 45°C to obtain a uniform slurry. The prepared slurry was coated onto the lithium negative electrode and then dried under vacuum at 100°C for 24 hours. Finally, a 2032-type button cell was assembled using NCM811 coated with solid electrolyte as the positive electrode, lithium metal as the negative electrode, and a solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 84.94% after 300 cycles at 1C rate.

[0099] Example 13:

[0100] In this embodiment, 0.5g of polyvinylidene fluoride (PVDF) and 1g of lithium lanthanum zirconium oxide (LLZO) powder were added to 10g of acetonitrile and stirred at a constant speed of 1500 rpm for 4 hours at room temperature to prepare an organic-inorganic composite solid electrolyte slurry. The slurry was then cast onto a polydifluorostyrene sulfonic acid membrane using a casting method and subjected to crosslinking polymerization at a specific temperature. The conditions were 300℃ in a sealed container for 1 hour to obtain the organic-inorganic composite solid electrolyte membrane. The composite solid electrolyte membrane had a thickness of 100 μm and was cut into discs with a diameter of 19 mm for later use. Electrochemical tests showed that the room temperature ionic conductivity of the composite solid electrolyte was 0.12 mS / cm, the electrochemical window reached 4.6 V, and the lithium-ion transference number was 0.9. A composite membrane prepared by combining LLZO powder without PVDF with a polydifluorostyrene sulfonic acid membrane served as a control group. The preparation method of the positive electrode sheet is as follows: 80 mg of lithium nickel manganese oxide positive electrode powder with a surface layer of polyvinylidene fluoride as the precursor, 10 mg of sodium carboxymethyl cellulose binder, and 10 mg of Ketjen black conductive agent are uniformly dispersed in NMP solvent. After grinding in a mortar for 1 hour, the powder is coated onto aluminum foil and vacuum dried at 100°C for 24 hours to obtain a lithium nickel manganese oxide positive electrode sheet, which is then cut into 10 mm diameter discs for later use. The preparation method of the polymer surface layer on the surface of the positive electrode active material is as follows: 0.5 g of polyvinylidene fluoride and 0.5 g of lithium nickel manganese oxide powder are mixed in 2 g of NMP and stirred at a constant speed of 1500 r / min for 4 hours at room temperature to obtain a suspension. The obtained suspension is stirred at a constant speed of 3000 r / min at 45°C for 72 hours to allow polyvinylidene fluoride to polymerize on the surface of the lithium nickel manganese oxide powder, thus obtaining a lithium nickel manganese oxide suspension containing a surface layer. The suspension was dried in a vacuum oven at 40°C for 72 hours to obtain lithium nickel manganese oxide powder material with a surface layer of polyvinylidene fluoride as the precursor. The preparation method of the solid electrolyte coating layer on the positive electrode surface was as follows: 1g of epoxy resin-LiPF6-Li3OCl (mass ratio 1:1:1) composite solid electrolyte powder was uniformly dispersed in 4g of N-methylpyrrolidone solvent, and stirred at 300°C and 3000r / min for 1 hour to prepare a uniform slurry. This slurry was then coated onto the positive electrode and dried under vacuum at 100°C for 24 hours. The preparation method of the solid electrolyte coating layer on the negative electrode surface was as follows: 1g of epoxy resin-LiPF6-Li3OCl (mass ratio 1:1:1) composite solid electrolyte powder was uniformly dispersed in 4g of N-methylpyrrolidone solvent, and stirred at 300°C and 3000r / min for 1 hour to prepare a uniform slurry. This slurry was then coated onto the lithium negative electrode and dried under vacuum at 100°C for 24 hours. Finally, a 2016-type button cell was assembled using lithium nickel manganese oxide coated with a solid electrolyte as the positive electrode, lithium metal as the negative electrode, and a solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 87% after 300 cycles at 1C rate.

[0101] Example 14:

[0102] In this embodiment, 2g of poly(vinylidene fluoride-hexafluoropropylene) and 1g of Li3OCl powder were added to 10g of ethanol and stirred at a constant speed of 1500r / min for 4h at room temperature to prepare an organic-inorganic composite solid electrolyte slurry. The slurry was then coated onto a PP membrane using a casting method and kept in a sealed container at 40℃ for 72h to obtain an organic-inorganic composite solid electrolyte membrane. The composite solid electrolyte membrane had a thickness of 200μm and was cut into discs with a diameter of 19mm for later use. Electrochemical tests showed that the room temperature ionic conductivity of the composite solid electrolyte was 0.14mS / cm, the electrochemical window reached 4.6V, and the lithium-ion transference number was 0.91. A composite membrane prepared by combining Li3OCl powder without poly(vinylidene fluoride-hexafluoropropylene) with a PP membrane served as a control group. The preparation method of the positive electrode sheet is as follows: 80 mg of lithium cobalt oxide positive electrode powder with a surface layer of poly(vinylidene fluoride-hexafluoropropylene) precursor, 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 are uniformly dispersed in NMP solvent, ground in a mortar for 1 h, coated on nickel foam, and vacuum dried at 100℃ for 24 h to obtain the lithium cobalt oxide positive electrode sheet. The preparation method of the polymer surface layer on the surface of the positive electrode active material is as follows: 0.5 g of poly(vinylidene fluoride-hexafluoropropylene) and 0.5 g of lithium cobalt oxide powder are mixed in 2 g of NMP, and stirred at a constant speed of 1500 r / min for 4 h at room temperature to obtain a suspension. The obtained suspension was stirred at 3000 r / min at 45℃ for 72 h to polymerize poly(vinylidene fluoride-hexafluoropropylene) on the surface of lithium cobalt oxide powder, thus obtaining a lithium cobalt oxide suspension containing a surface layer. The suspension was then dried in a vacuum oven at 40℃ for 72 h to obtain lithium cobalt oxide powder material with a surface layer of poly(vinylidene fluoride-hexafluoropropylene) as the precursor. The preparation method of the solid electrolyte coating layer on the positive electrode surface was as follows: 1 g of polybenzothiazole-LiClO4-Li3InCl6 (mass ratio 1:1:1) composite solid electrolyte powder was uniformly dispersed in 9 g of NMP solvent and stirred at 100 r / min at 45℃ for 72 h to obtain a uniform slurry. This slurry was then coated onto the positive electrode and dried under vacuum at 100℃ for 24 h. The negative electrode sheet was prepared 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 hour, coated on a stainless steel mesh, and vacuum dried at 100°C for 24 hours. It was then cut into 10 mm diameter discs for later use. A composite negative electrode was then prepared using a melt method. Lithium metal was heated to 180°C and melted. The negative electrode sheet was then immersed in the molten lithium metal and cooled to room temperature to obtain the amorphous carbon composite negative electrode. Finally, a cylindrical battery was assembled using lithium cobalt oxide coated with a solid electrolyte as the positive electrode, amorphous carbon as the negative electrode, and a solid electrolyte composite membrane as the electrolyte. At 1C rate, the capacity retention rate was 80% after 50 cycles.

[0103] Example 15:

[0104] In this embodiment, 3g of poly(ethylene fluoride) propylene oxide and 0.2g of Li₂O·SiO₂ powder were added to 20g of tetrahydrofuran, and stirred at a constant speed of 1500 rpm for 4 hours at room temperature to prepare an organic-inorganic composite solid electrolyte slurry. The slurry was then spin-coated onto a perfluorosulfonic acid-polytetrafluoroethylene membrane at 600 rpm and kept in a sealed container at 120°C for 18 hours, resulting in an organic-inorganic composite solid electrolyte membrane with a thickness of 50 μm. This membrane was then cut into discs with a diameter of 19 mm for later use. Electrochemical tests showed that the composite solid electrolyte had a room temperature ionic conductivity of 0.15 mS / cm, an electrochemical window of 4.55 V, and a lithium-ion transference number of 0.95. A composite membrane prepared by combining Li₂O·SiO₂ powder without poly(ethylene fluoride) propylene oxide with a perfluorosulfonic acid-polytetrafluoroethylene membrane served as a control group. The positive electrode was prepared as follows: 80 mg of lithium manganese iron phosphate positive electrode powder, 7 mg of PVDF binder, 3 mg of poly(ethylene fluoride)-Li₂O·SiO₂ composite solid electrolyte powder, and 10 mg of acetylene black conductive agent were uniformly dispersed in NMP solvent. After grinding in a mortar for 1 hour, the powder was coated onto carbon-coated aluminum foil and vacuum dried at 120°C for 24 hours to obtain the lithium manganese iron phosphate positive electrode, which was then cut into 10 mm diameter discs for later use. The solid electrolyte coating layer on the positive electrode surface was prepared by magnetron sputtering to form an LLTO coating with a thickness of 200 nm on the surface of the positive electrode. The negative electrode was prepared 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. After grinding in a mortar for 1 hour, the powder was coated onto a nickel mesh and vacuum dried at 120°C for 24 hours to obtain the mesophase carbon microsphere electrode, which was then cut into 10 mm diameter discs for later use. A lithium-containing composite anode was then prepared using an electrochemical method, employing a constant current method at 0.1 mA / cm². -2 The composite negative electrode was prepared by discharging to a current density of 0.001V. Finally, a 2016-type button cell was assembled using an NCM622 positive electrode with a solid electrolyte coating, an mesophase carbon microsphere negative electrode, and a solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 94% after 300 cycles at 1C rate.

[0105] Example 16:

[0106] In this embodiment, 0.5g of polytrifluoroethylene (PTFE) and 1g of sodium lanthanum zirconium tantalum oxide (SLAM) powder were added to 10g of diphenyl ether and stirred at a constant speed of 1500 rpm for 4 hours at room temperature to prepare an organic-inorganic composite solid electrolyte slurry. The slurry was coated onto a cellulose membrane using a coating method and then crosslinked polymerized at a certain temperature in a sealed container at 100°C for 24 hours to obtain the organic-inorganic composite solid electrolyte membrane. The membrane was cut into discs with a diameter of 19mm and a thickness of 40μm. Electrochemical tests showed that the room temperature ionic conductivity of the composite solid electrolyte was 0.13 mS / cm, the electrochemical window reached 4.7V, and the sodium ion transference number was 0.93. A solid electrolyte membrane prepared from sodium lanthanum zirconium tantalum oxide powder without PTFE was used as a control group. The preparation method of the positive electrode sheet is as follows: 80 mg of sodium manganate positive electrode powder with a surface layer of polytrifluoroethylene as the precursor, 1 mg of PVDF binder, 10 mg of electrolyte slurry, and 10 mg of Super P conductive agent are uniformly dispersed in NMP solvent. After grinding in a mortar for 1 hour, the mixture is coated onto aluminum foil and vacuum dried at 100°C for 24 hours to obtain the sodium manganate positive electrode sheet, which is then cut into 10 mm diameter discs for later use. The preparation method of the polymer surface layer on the surface of the positive electrode active material is as follows: 0.5 g of polytrifluoroethylene and 0.5 g of sodium manganate positive electrode powder are mixed in 2 g of NMP and stirred at a constant speed of 1500 r / min for 4 hours at room temperature to obtain a suspension. The obtained suspension is stirred at a constant speed of 3000 r / min at 45°C for 72 hours to allow polytrifluoroethylene to polymerize on the surface of the sodium manganate positive electrode powder, thus obtaining a sodium manganate suspension containing the surface layer. The suspension was dried in a vacuum oven at 40°C for 72 hours to obtain sodium manganate powder material with a surface layer of polytrifluoroethylene as the precursor. The solid electrolyte coating layer on the positive electrode surface was prepared by magnetron sputtering to form a sodium lanthanum zirconium oxide coating with a thickness of 200 nm. The solid electrolyte coating layer on the negative electrode surface was also prepared by magnetron sputtering to form a sodium lanthanum zirconium oxide coating with a thickness of 200 nm on the sodium negative electrode surface. Finally, using 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, a 2016-type button battery was assembled, exhibiting a capacity retention of 89.4% after 300 cycles at 1C rate.

[0107] Example 17:

[0108] In this embodiment, 0.1 g of polyvinyl fluoride (PVC) and 1 g of sodium lanthanum titanium oxide powder were mixed in 5 g of dimethyl sulfoxide (DMSO) and stirred at a constant speed of 1500 r / min for 4 h at room temperature to prepare an organic-inorganic composite solid electrolyte slurry. The slurry was coated onto a cellulose membrane using a coating method and then crosslinked polymerized at a certain temperature in a sealed container at 100°C for 24 h to obtain the organic-inorganic composite solid electrolyte membrane. The membrane was cut into discs with a diameter of 19 mm and a thickness of 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 without PVC composite was used as a control group. The positive electrode was prepared 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 hours, the mixture was coated onto aluminum foil and vacuum dried at 120°C for 24 hours to obtain the Prussian blue positive electrode. The coated electrode was then cut into 10 mm diameter discs for later use. The solid electrolyte coating on the positive electrode surface was prepared by vapor deposition of a sodium lanthanum titanium oxide coating with a thickness of 200 nm. The solid electrolyte coating on the negative electrode surface was prepared by vapor deposition of a sodium lanthanum titanium oxide coating with a thickness of 200 nm. Finally, a 2032-type button cell was assembled using Prussian blue positive electrode, metallic sodium as the negative electrode, and a solid electrolyte composite membrane as the electrolyte. The cell retained 83% of its capacity after 300 cycles at 1C rate.

[0109] Example 18:

[0110] In this embodiment, 0.5 g of polyethylene trifluoroethylene and 1 g of Na2O·Al2O3 powder were added to 10 g of N,N-dimethylformamide and stirred at a constant speed of 1500 r / min for 4 h at room temperature to prepare an organic-inorganic composite solid electrolyte slurry. The slurry was coated onto a glass plate using a doctor blade and crosslinked polymerized at a certain temperature in a sealed container at 300°C for 1 h to obtain an organic-inorganic composite solid electrolyte membrane. The composite solid electrolyte membrane had a thickness of 100 μm and was cut into discs with a diameter of 19 mm for later use. Electrochemical tests showed that the room temperature ionic conductivity of the composite solid electrolyte was 0.15 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 without the polyethylene trifluoroethylene was used as a control group. The positive electrode sheet is prepared as follows: 80 mg of sodium manganese phosphate positive electrode powder, 10 mg of PVDF binder, 0.1 mg of polyethylene trifluoroethylene-Na2O·Al2O3 electrolyte slurry binder, and 10 mg of Ketjen black conductive agent are uniformly dispersed in NMP solvent. After grinding in a mortar for 1 hour, the mixture is coated onto aluminum foil and vacuum dried at 100°C for 24 hours to obtain the positive electrode sheet, which is then cut into 10 mm diameter discs for later use. The solid electrolyte coating layer on the positive electrode surface is prepared as follows: 1 g of polybenzothiazole-NaClO4-Na3InCl6 (mass ratio 1:1:1) composite solid electrolyte powder is uniformly dispersed in 9 g of NMP solvent and stirred at 100 r / min at 45°C for 72 hours to obtain a uniform slurry. This slurry is then coated onto the positive electrode and dried under vacuum at 100°C for 24 hours. The negative electrode sheet was prepared 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 uniformly dispersed in ethanol solvent, ground in a mortar for 1 hour, and then coated onto carbon cloth and vacuum dried at 120°C for 24 hours to obtain the tin-silicon alloy negative electrode sheet. A tin-silicon alloy-sodium metal composite negative electrode was prepared by roller pressing at 300°C and 20 MPa, and cut into 10 mm diameter discs for later use. Finally, a 2016-type button cell was assembled using a sodium manganese phosphate positive electrode coated with a solid electrolyte, a tin-silicon alloy negative electrode, and a solid electrolyte composite membrane as the electrolyte. The capacity retention rate was 87% after 300 cycles at 1C rate.

[0111] Example 19:

[0112] In this embodiment, 2g of polyvinylidene chloride (PVDC) and 1g of K3OCl powder were added to 10g of dimethylacetamide and stirred at a constant speed of 1500 rpm for 4 hours at room temperature to prepare an organic-inorganic composite solid electrolyte slurry. The slurry was then cast onto a stainless steel plate and kept in a sealed container at 40°C for 72 hours. This yielded an organic-inorganic composite solid electrolyte membrane with a thickness of 200 μm, which was cut into 19 mm diameter discs for later use. Electrochemical tests showed that the composite solid electrolyte had a room temperature ionic conductivity of 0.1 mS / cm, an electrochemical window of 4.5 V, and a potassium ion transference number of 0.9. A solid electrolyte membrane prepared without PVDC-containing K3OCl powder served as a control group. The positive electrode sheet is prepared as follows: 80 mg of nickel-cobalt-manganese positive electrode powder with a surface layer of polyvinylidene chloride as the precursor, 10 mg of PVDF binder, 0.01 mg of organic-inorganic composite solid electrolyte slurry, and 10 mg of BLACK PEARLS2000 conductive agent are uniformly dispersed in NMP solvent. After grinding in a mortar for 1 hour, the mixture is coated onto nickel foam and vacuum dried at 100°C for 24 hours to obtain the positive electrode sheet. The polymer surface layer on the surface of the positive electrode active material is prepared by mixing 0.5 g of polyvinylidene chloride and 0.5 g of nickel-cobalt-manganese positive electrode powder in 2 g of NMP and stirring at a constant speed of 1500 r / min for 4 hours at room temperature to obtain a suspension. The obtained suspension is then stirred at a constant speed of 3000 r / min at 45°C for 72 hours to allow polyvinylidene chloride to polymerize on the surface of the nickel-cobalt-manganese positive electrode powder, thus obtaining a nickel-cobalt-manganese suspension containing the surface layer. The suspension was dried in a vacuum oven at 40°C for 72 hours to obtain a nickel-cobalt-manganese powder material with a surface layer of polyvinylidene chloride as the precursor. The solid electrolyte coating on the positive electrode surface was prepared as follows: 1g of polyethylene carbonate-KClO4 (mass ratio 1:1) composite solid electrolyte powder was uniformly dispersed in 9g of NMP solvent and stirred at 100r / min for 72 hours at 45°C to obtain a uniform slurry. This slurry was then coated onto the positive electrode and dried under vacuum at 100°C for 24 hours. The negative electrode was prepared as follows: 80mg of copper-silicon alloy powder, 10mg of polyolefin binder, and 10mg of BLACK PEARLS2000 conductive agent were uniformly dispersed in tetrahydrofuran solvent, ground in a mortar for 1 hour, and then coated onto a carbon plate and vacuum dried at 100°C for 24 hours to obtain the negative electrode. The preparation method of the solid electrolyte coating layer on the negative electrode surface is as follows: 1g of polyethylene carbonate-KClO4 (mass ratio 1:1) composite solid electrolyte powder is uniformly dispersed in 9g of NMP solvent, and stirred at 100r / min for 72h at 45℃ to obtain a uniform slurry. This slurry is then coated onto the negative electrode and dried under vacuum at 100℃ for 24h. Finally, a pouch cell is assembled using a nickel-cobalt-manganese ternary electrode coated with solid electrolyte as the positive electrode, a copper-silicon alloy as the negative electrode, and a solid electrolyte composite membrane as the electrolyte. The capacity retention rate is 88% after 30 cycles at 1C rate.

[0113] Example 20:

[0114] In this embodiment, 3g of poly(vinylidene chloride-hexachloropropylene) and 0.2g of K₂O·SiO₂ powder were added to 20g of N-methylpyrrolidone and stirred uniformly at 1500 rpm for 4 hours at room temperature to obtain an organic-inorganic composite solid electrolyte slurry. The slurry was coated onto a Nafion membrane using a doctor blade and kept in a sealed container at 120°C for 18 hours to obtain the organic-inorganic composite solid electrolyte membrane. The composite solid electrolyte membrane had a thickness of 40 μm and was cut into 19 mm diameter discs for later use. Electrochemical tests showed that the room temperature ionic conductivity of the composite solid electrolyte was 0.12 mS / cm, the electrochemical window reached 4.5 V, and the potassium ion transference number was 0.9. A composite membrane prepared by combining K₂O·SiO₂ powder without poly(vinylidene chloride-hexachloropropylene) with a Nafion membrane served as a control group. The positive electrode sheet was prepared 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 uniformly dispersed in NMP solvent. After grinding in a mortar for 1 hour, the mixture was coated onto carbon-coated aluminum foil and vacuum dried at 120°C for 24 hours to obtain the Prussian blue positive electrode sheet, which was then cut into 10 mm diameter discs for later use. The solid electrolyte coating layer on the positive electrode surface was prepared as follows: 1 g of Nafion was uniformly dispersed in 9 g of NMP solvent and stirred at 1500 r / min at 120°C for 12 hours to obtain a uniform slurry. This slurry was then coated onto the positive electrode and dried under vacuum at 100°C for 24 hours. The preparation method of the solid electrolyte coating layer on the negative electrode surface is as follows: 1g of Nafion is uniformly dispersed in 9g of NMP solvent, and stirred at 1500r / min for 12h at 120℃ to obtain a uniform slurry. After coating the negative electrode, it is dried under vacuum at 100℃ for 24h. Finally, a 2016-type button cell is assembled using the Prussian blue positive electrode coated with solid electrolyte, the potassium metal negative electrode, and the solid electrolyte composite membrane as the electrolyte. The capacity retention rate is 94% after 300 cycles at 1C rate.

Claims

1. An in-situ polymerized organic-inorganic composite electrolyte, characterized in that: The in-situ polymerized organic-inorganic composite electrolyte is composed of an inorganic oxide solid electrolyte capable of conducting alkali metal cations, an unsaturated polymer formed by the reaction of a halogen-containing polymer and undergoing 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; the mass ratio of the polar organic solvent to the halogen-containing polymer is 5~50:

1. The oxygen atoms in the inorganic oxide solid electrolyte are Lewis bases, and the inorganic oxide solid electrolyte is one of the following substances: 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; garnet-type inorganic solid electrolyte 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; garnet-type inorganic solid electrolyte 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; garnet-type inorganic solid electrolyte 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; perovskite-type inorganic solid electrolyte A 3x La 0.67-x TiO3, where 0.04 < x < 0.17, A is one or more of Li, Na or K; inverse 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 inorganic oxide solid electrolyte has a particle size of 1 nm to 100 μm and a room temperature ionic conductivity of not less than 10. -4 mS / cm, inorganic oxide solid electrolytes are all single-ion conductor solid electrolytes, and their alkali metal cation transfer number, that is, the percentage of charge transferred by alkali metal cations to the total charge, is 1. The halogen-containing polymer is a polymer containing one or two of the halogen atoms, including F and Cl, such as polyvinylidene fluoride, poly(vinylidene fluoride-hexafluoropropylene), poly(tetrafluoroethylene-ethylene), polytrifluoroethylene, polyethylene trifluoroethylene, polyvinylidene chloride, poly(vinylidene chloride-hexachloropropylene), and poly(tetrachloroethylene-ethylene), with a molecular weight of 1,000 to 10,000,000. The polar organic solvent includes one or more of acetonitrile, ethanol, tetrahydrofuran, diphenyl ether, dimethyl sulfoxide, N,N-dimethylformamide, dimethylacetamide, N-methylpyrrolidone, hexamethylphosphoric triamine, hexaethylphosphoric triamine, triethyl phosphate, trimethyl phosphate, propylene carbonate, and fluoropropylene carbonate. The in-situ polymerized organic-inorganic composite electrolyte is obtained by the following preparation method: 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, and at a certain temperature, the oxygen atoms of the Lewis base on the surface of the inorganic oxide solid electrolyte induce the halogen-containing polymer to remove halogen elements, thereby generating an unsaturated polymer containing C=C groups in situ. The specific preparation process includes the following steps: (1) A suspension is prepared by stirring the oxide solid electrolyte powder material, halogen-containing polymer and polar organic solvent at a speed of 100-3000 r / min for 1-72 h at room temperature. (2) The slurry obtained in step (1) is coated onto a flat or film-like skeleton material by casting, casting, spin coating or coating method, and then crosslinked and polymerized in situ in a closed container at a temperature of 40 to 300°C for 1-72 hours to form a diaphragm.

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 1~500 μm. When coated on a flat plate or dense membrane, the measured thickness is the thickness of the organic-inorganic composite solid electrolyte. The unsaturated polymer is generated by an in-situ reaction between a halogen-containing polymer and an inorganic oxide solid electrolyte. The reaction mechanism is as follows: ; Where A and B are H or halogen atoms respectively, and X is a halogen atom, which includes one or two of F and Cl. D is a haloalkyl segment C y H z M (2y-z) , where M is one or both of F and Cl atoms, 0≤y≤3, when y is 0, the polymer chain only has -CAX-CHB- as the repeating unit, 0≤z≤2y, where y and z are both 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 framework material; the membrane-like framework material is a dense membrane or a porous membrane. The dense membrane is a composite membrane composed of one or more of the following: perfluorosulfonic acid-polytetrafluoroethylene membrane, polytrifluorostyrene sulfonic acid membrane, polydifluorostyrene sulfonic acid membrane, polyaryletherketone sulfonic acid membrane, polyimide sulfonic acid membrane, and sulfonated polysulfone membrane; the porous membrane is a composite membrane composed of one or more of the following: PP membrane, PE membrane, cellulose nonwoven membrane, polyimide nonwoven membrane, seaweed fiber nonwoven membrane, aramid nonwoven membrane, polyaryletheramide nonwoven membrane, polypropylene nonwoven membrane, glass fiber membrane, and polyethylene terephthalate nonwoven membrane.

4. A solid electrolyte membrane employing the in-situ polymerized organic-inorganic composite electrolyte as described in claim 1, characterized in that: The transference number of alkali metal cations is not less than 0.

9.

5. The application of an organic-inorganic composite electrolyte polymerized in situ according to any one of claims 1-3, characterized in that: It is used as a separator in the assembly of solid-state batteries.

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