A polymer electrolyte precursor for preparing a solid-state battery or a semi-solid-state battery, and a preparation method and application thereof

Abstract

The present application relates to a kind of polymer electrolyte precursor for preparing solid-state battery or semi-solid battery and its preparation method and application.The present application provides a kind of polymer electrolyte precursor, which includes: A) polyurethane;B) chemically crosslinkable monomer and / or prepolymer;C) lithium salt;D) initiator;E) electrolyte solvent;F) optional additive;Wherein, the polyurethane is obtained by the reaction of polyol with average functionality of 1.8~2.2, isocyanate with average functionality of 1.8~2.2, chain extender and optional auxiliary agent, the polyurethane is dissolved or dispersed in the polymer electrolyte precursor at 25 DEG C, the viscosity of the polymer electrolyte precursor determined at 25 DEG C is not higher than 400 cP.The polymer electrolyte precursor of the present application has excellent flowability and dispersibility, is suitable for in-situ injection into battery structure for polymerization, simplifies production process and improves safety.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solid-state batteries or semi-solid-state batteries, and particularly relates to a polymer electrolyte precursor for preparing a solid-state battery or a semi-solid-state battery and a preparation method and application thereof. BACKGROUND

[0002] With the increasing demand for high energy density energy storage devices, high-power rechargeable lithium ion batteries have become a research hotspot. However, there is a natural contradiction between the safety and energy density of the battery: as the energy density increases, it becomes increasingly difficult to maintain or even further improve safety.

[0003] The liquid electrolyte used in traditional lithium ion batteries has safety hazards such as easy volatilization, easy combustion and easy leakage, which seriously limits its promotion in high-power and high-safety application scenarios. Especially under the background of continuously increasing energy density, the use of organic liquid electrolyte in lithium ion batteries may cause fire or even explosion risks during operation.

[0004] In contrast, solid-state lithium batteries can effectively avoid the above risks and have the potential to increase the energy density to more than 300 Wh / kg, so they are widely considered as one of the most promising next-generation battery technologies.

[0005] Existing solid-state or semi-solid-state electrolytes are mainly divided into inorganic electrolytes and polymer electrolytes. Although inorganic electrolytes have high ionic conductivity, their preparation usually requires high-temperature sintering, resulting in problems such as high brittleness, poor interface contact with electrodes, and poor processability. In contrast, polymer electrolytes have attracted widespread attention due to their good flexibility, easy processing, and good contact with electrodes. However, polymer electrolytes generally have low ionic conductivity and high interface impedance.

[0006] To improve the performance of polymer electrolytes, researchers have proposed various modification strategies, such as introducing ion-conducting additives, plasticizers, and using in-situ polymerization methods. Among them, in-situ polymerization technology has good compatibility with existing battery manufacturing processes, can effectively reduce interface impedance, and simplify the preparation process, so it has become a research focus. For example, patent KR102024889B1 uses polyethylene oxide (PEO) as a matrix to form a polymer electrolyte through solvent evaporation and thermal curing, but has problems such as poor thermal stability, the need for an additional vacuum drying step, and low ionic conductivity. Patent CN114085325A uses polyvinylidene fluoride-polyhexafluoropropylene and polymerizable monomers containing ethylene oxide units to prepare ion-conducting semi-interpenetrating network polymers, although the performance is improved, but the preparation process is complex. Overall, the in-situ polymerization technology currently mainly exists the problem of being difficult to realize the large-scale production of solid-state lithium batteries.

[0007] Therefore, it is urgent to develop a polymer electrolyte system with high ionic conductivity, low interface impedance, good processability and safety to meet the application requirements of solid-state or semi-solid lithium batteries suitable for stable operation at high voltage and mass production. SUMMARY

[0008] The present application aims to provide a polymer electrolyte precursor for preparing solid-state or semi-solid batteries, a preparation method thereof and its application in solid-state or semi-solid batteries to solve the problems of low ionic conductivity, high interface impedance, poor processability and thermal stability in existing polymer electrolyte systems, improve the safety and comprehensive performance of the battery and be suitable for mass production.

[0009] To achieve this goal, the present application provides the following technical solutions:

[0010] A polymer electrolyte precursor for preparing solid-state or semi-solid batteries, the precursor comprising a polyurethane, a chemically cross-linkable monomer and / or prepolymer, a lithium salt, an initiator, an electrolyte solvent comprising a carbonate solvent, and an optional additive, the polyurethane being dissolved or dispersed in the polymer electrolyte precursor at 25℃, and the viscosity of the polymer electrolyte precursor being not higher than 400 cP (mPa·s) at 25℃. This system has good flowability and dispersibility, is suitable for in-situ injection into the battery structure for in-situ polymerization, and can effectively improve the interface contact performance and electrochemical stability of the battery.

[0011] Further, the present application also provides a method for preparing the polymer electrolyte precursor of the present application, comprising: dissolving or dispersing a polyurethane in an electrolyte solvent, adding a chemically cross-linkable monomer and / or prepolymer, an initiator and a lithium salt, and stirring uniformly to obtain the precursor; or dissolving or dispersing a polyurethane in an electrolyte (i.e. an electrolyte containing a lithium salt) of an electrolyte solvent and a lithium salt, adding a chemically cross-linkable monomer and / or prepolymer and an initiator, and stirring uniformly to obtain the precursor of the present application.

[0012] Further, the present application also provides a polymer electrolyte formed by injecting the polymer electrolyte precursor of the present application into a battery and performing in-situ polymerization. The polymer electrolyte can form a semi-interpenetrating polymer network structure, significantly reduce the interface impedance and improve the ion conduction efficiency.

[0013] Further, the present application also provides a method for preparing a solid-state or semi-solid battery, comprising the following steps: injecting the above-mentioned polymer electrolyte precursor into a dry cell; heating for in-situ polymerization; and then performing sealing treatment.

[0014] Alternatively, the present application also provides a method for preparing a solid-state battery or a semi-solid-state battery, which comprises pre-coating the above polymer electrolyte precursor on the surface of an electrode and / or a separator, heating for in-situ polymerization, solidifying it on the surface of the electrode and / or the separator, and then obtaining the corresponding solid-state battery or semi-solid-state battery by lamination or winding.

[0015] The polymer electrolyte precursor of the present application has a wide source of raw materials, controllable cost, low viscosity, good injection property and polymerization activity, and can be used to scale up the production of solid-state batteries or semi-solid-state batteries with high safety and high energy density through in-situ polymerization process, thus having good prospects for industrial application.

[0016] It should be noted that the above description does not disclose all the embodiments and all the advantages of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The optical image of the polymer electrolyte precursor obtained from Comparative Example CE7 after standing at 25℃ for 12 h (in a viscous and non-flowing state). DETAILED DESCRIPTION

[0018] The embodiments of the present application will be described below, but the present application is not limited thereto. The present application is not limited to each of the configurations described below, and various modifications can be made within the scope of the present application, and embodiments obtained by appropriately combining the technical means disclosed in each of the different embodiments and examples are also included in the technical scope of the present application. In addition, the documents described in the present specification are all incorporated by reference in the present specification.

[0019] Unless otherwise defined, the technical and scientific terms used in the present specification have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs.

[0020] In the context of describing the present specification (especially in the context of the appended claims), the terms "one", "a", and "the" and similar language will be interpreted to cover both the singular and the plural, unless otherwise indicated by the context or clearly contradicted by the specification.

[0021] In the present specification, the numerical range represented by "numerical value A to numerical value B" or "numerical value A-numerical value B" means that the end point values A and B and all ranges between the end points are included.

[0022] In the present specification, the meaning represented by "may" is generally used to include both the meaning of performing a certain process and the meaning of not performing a certain process. Note that in the present specification, "may" in "chemically crosslinkable monomer and / or prepolymer" means the meaning of "can".

[0023] In this specification, "optional" or "optionally" means that the event or situation described below may or may not occur, and the description includes both the scenario in which the event occurs and the scenario in which the event does not occur.

[0024] In this specification, the terms "some specific / preferred embodiments," "other specific / preferred embodiments," "some specific / preferred technical solutions," and "other specific / preferred technical solutions" refer to specific elements (e.g., features, structures, properties, and / or characteristics) related to the described embodiment that are included in at least one of the embodiments described herein, and may or may not exist in other embodiments. Furthermore, it should be understood that these elements can be combined in any suitable manner in various embodiments.

[0025] In this specification, the term "comprising" and any variations thereof are intended to cover non-exclusive inclusion. The use of phrases such as "does not contain" or "does not include" is not intended to exclude the presence of trace amounts of related compounds or chemical structures that may be present but were not intentionally used, such as environmental contaminants.

[0026] For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such processes, methods, products, or devices.

[0027] In this specification, expressions such as "containing A, B and / or C" or "including A, B and / or C" mean containing A or B or C, or containing any two of A and C, or containing all three of A, B and C.

[0028] In this specification, the term "organic" refers to a carbon-containing compound.

[0029] In this specification, the term "inorganic" refers to compounds that do not contain carbon atoms except for carbonates and oxides of carbon.

[0030] In this specification, the term "polymer" refers to a molecule comprising a large number of similar units bonded together by covalent bonds.

[0031] In this specification, the parentheses in the terms "(meth)acrylic acid", "(meth)acrylate" and "(meth)acrylamide" indicate that they include acrylic acid and / or methacrylic acid, alkyl acrylate and / or alkyl methacrylate, acrylamide and / or methacrylamide.

[0032] In this specification, the term "solid-state battery" refers to a secondary battery system that uses solid materials (including non-fluid materials) as the electrolyte and separator. The term "semi-solid-state battery" refers to a battery in which the electrolyte is in a semi-solid state (gel or slurry).

[0033] In this specification, the term "polymer electrolyte" refers to an electrolyte material that uses a polymer matrix as a carrier and is capable of ion conduction therein, including but not limited to solid polymer electrolytes, gel polymer electrolytes, composite polymer electrolytes, ion gels, and other categories.

[0034] In this specification, the term "dispersion" means that polyurethane particles suspended in a polymer electrolyte precursor do not undergo visible precipitation at room temperature for 24 hours.

[0035] polymer electrolyte precursor

[0036] This invention provides a polymer electrolyte precursor for preparing solid-state batteries or semi-solid-state batteries, the precursor comprising:

[0037] A) Polyurethane;

[0038] B) Chemically crosslinkable monomers and / or prepolymers;

[0039] C) Lithium salts;

[0040] D) Initiator;

[0041] E) Electrolyte solvent;

[0042] F) Optional additives;

[0043] The polyurethane is prepared by reacting a polyol with an average functionality of 1.8 to 2.2, an isocyanate with an average functionality of 1.8 to 2.2, a chain extender, and optional additives. The polyurethane is dissolved or dispersed in the polymer electrolyte precursor at 25°C, and the viscosity of the polymer electrolyte precursor measured at 25°C is not higher than 400 cP.

[0044] The polymer electrolyte precursor of this invention utilizes a suitable, primarily physically crosslinked polyurethane structure, enabling it to dissolve and / or disperse well in the electrolyte solvent at room temperature (25°C). This eliminates the need for additional organic solvents, such as DMF, which require subsequent vacuum drying for removal, simplifying the system composition and improving safety. The electrolyte solvent of this invention, particularly carbonate solvents, not only functions as a solvent but also as a plasticizer (although carbonate solvents are not classified as component F in this invention), effectively improving the flexibility of the polymer chain and enhancing the migration ability of lithium ions, thereby increasing the overall ionic conductivity. By controlling the viscosity and particle size of the polymer electrolyte precursor, this invention achieves excellent flowability and dispersibility, making it suitable for in-situ injection polymerization into battery structures, effectively improving the interfacial contact performance and electrochemical stability of the battery.

[0045] In this invention, each component of the raw material can be used alone, or two or more components can be used in combination in a desired proportion. Each component will be explained in detail below.

[0046] Component A)

[0047] Component A) of this invention is polyurethane. Polyurethane is a polymer formed by the addition polymerization reaction of polyols and polyisocyanates, typically containing chain extenders and optional auxiliaries (such as catalysts or stabilizers). In this invention, polyurethane is prepared by reacting a polyol with an average functionality of 1.8 to 2.2 and an isocyanate with an average functionality of 1.8 to 2.2, forming a network structure dominated by physical crosslinking. Polyurethane, as the core skeleton material of this invention, mainly plays a role in constructing the physical crosslinking network, retaining the electrolyte, and providing mechanical strength and flexibility. Compared to other polymers such as polyacrylonitrile, polyvinylidene fluoride, and polyethylene oxide, polyurethane-based polymer electrolytes have a higher electrochemical stability range and better electrochemical stability at both positive and negative electrodes. Furthermore, the polyurethane of this invention can be well dissolved and dispersed in electrolyte solvents without the need for additional organic solvents (such as DMF), improving safety and processability.

[0048] In this invention, the average functionality of a polyol refers to the average number of hydroxyl groups in each polyol molecule. The average functionality of an isocyanate refers to the average number of -NCO groups in each isocyanate molecule. Average functionality is derived from the number average. Alternatively, average functionality can be estimated using the number-average molecular weight (Mn) and the functional group mass fraction. The number-average molecular weight can be determined by gel permeation chromatography (GPC), preferably according to DIN 55672-1:2016-03. The number of functional groups can be determined by titration or spectrometry. Average functionality determines the crosslinking density and network structure of the polyurethane. Higher functionality results in more crosslinking points, a tighter polymer network, and higher mechanical strength, but may reduce chain mobility and affect ionic conductivity. In this invention, the average functionality of the polyol and isocyanate is controlled within the range of 1.8 to 2.2 to balance mechanical properties and ion transport capacity, ensuring sufficient physical crosslinking of the polyurethane matrix in the electrolyte while maintaining low viscosity and high ionic conductivity. In some preferred embodiments of the present invention, the average functionality of the polyol and isocyanate is preferably controlled in the range of 1.9 to 2.1, more preferably 2.

[0049] In some specific embodiments of the present invention, the number-average molecular weight of the polyol used to prepare polyurethane ranges from 200 to 10,000 g / mol, preferably from 200 to 8,000 g / mol, more preferably from 500 to 5,000 g / mol. For example, the polyol has number-average molecular weights of 500 g / mol, 600 g / mol, 700 g / mol, 800 g / mol, 900 g / mol, 980 g / mol, 1000 g / mol, 2000 g / mol, 3000 g / mol, 4000 g / mol, and 5000 g / mol. The average functionality of the polyol is 1.8 to 2.2, preferably from 1.9 to 2.1, and particularly 2. In some specific embodiments of the present invention, the polyol is selected from polyether polyols, polyester polyols, polycarbonate polyols, mixtures thereof, and their block copolymers. Preferably, the polyol is selected from polyether alcohols containing ether oxygen bonds, which have good flexibility and whose polyurethanes have good solubility or dispersibility in the precursors of the present invention. Polyether alcohols containing ether oxygen bonds include, but are not limited to, polyethylene glycol, polypropylene glycol, polytetrahydrofuran ether glycol, and tetrahydrofuran-propylene oxide copolyol or mixtures thereof. Suitable examples of commercially available polyols include Lupronol. ® 1000 (from BASF), Lupronol ® 1100 (from BASF), PolyTHF ® 1000 (from BASF), PolyTHF ®2000 (from BASF), GSE-2038 (from Takahashi Petrochemical), Lupraphen ® 1600 (from BASF), Eternacoll ® UH-200 (from UBE Corporation), etc. In some specific embodiments of the present invention, the isocyanate used to prepare the polyurethane includes aliphatic, cycloaliphatic, aryliphatic, and / or aromatic isocyanates, preferably aromatic, aliphatic, and / or cycloaliphatic diisocyanates. Examples of suitable diisocyanates include: trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, heptamethylene diisocyanate, octamethylene diisocyanate; 2-methylpentenyl-1,5-diisocyanate, 2-ethylbutenyl-1,4-diisocyanate, 1,4-butene diisocyanate, 1-isocyano-3,3,5-trimethyl-5-isocyanate methylcyclohexane; 1,4-bis(methyl)cyclohexane; 1,4-cyclohexane diisocyanate; 1-methyl-2,4-cyclohexane diisocyanate; 1-methyl-2, 6-Cyclohexane diisocyanate; 2,2'-Dicyclohexylmethane diisocyanate; 2,4'-Dicyclohexylmethane diisocyanate; 4,4'-Dicyclohexylmethane diisocyanate; 2,2'-Diphenylmethane diisocyanate; 2,4'-Diphenylmethane diisocyanate; 4,4'-Diphenylmethane diisocyanate; 1,5-Naphthalene diisocyanate; 2,4-Toluene diisocyanate; 2,6-Toluene diisocyanate; Diphenylmethane diisocyanate; 3,3'-Dimethylbiphenyl diisocyanate; 1,2-Diphenylethane diisocyanate and phenyl diisocyanate; and any mixtures thereof. Preferably, the isocyanates of the present invention are selected from diphenylmethane diisocyanate (MDI) and / or toluene diisocyanate (TDI). Examples of suitable commercially available polyisocyanate compounds include LUPRANAT. ® MS (from BASF) or LUPRANAT ® MIPS (from BASF), etc.

[0050] In some specific embodiments of the present invention, the chain extender used to prepare polyurethane is a diol, preferably a diol containing 2 to 6 carbon atoms, including but not limited to: 1,2-ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentanediol, or a mixture of two or more of the above diols. The chain extender is mainly used to adjust the molecular chain length and degree of crosslinking. The amount of chain extender used is typically 0.5% to 10% of the total mass of the polyol and isocyanate.

[0051] In addition, other additives, such as catalysts, light stabilizers, flame retardants, and antioxidants, can be selectively added during the preparation of polyurethane. These additives can be added individually or in any combination.

[0052] Methods for preparing polyurethane are well known. Typical methods involve reacting a polyol and an isocyanate at 80°C for 1–4 hours, adding chain extenders and auxiliaries, and continuing the reaction until a prepolymer or final polymer is formed. The reaction can be carried out under nitrogen protection to avoid side reactions.

[0053] In some specific embodiments of the present invention, the number-average molecular weight of the polyurethane of the present invention is less than 100,000 g / mol, and further, less than 60,000 g / mol; for example, the polyurethane has a number-average molecular weight of 10,000 g / mol, 20,000 g / mol, 30,000 g / mol, 40,000 g / mol, or 50,000 g / mol. Alternatively, the degree of polymerization of the polyurethane of the present invention is less than 500, and further, less than 300. In some preferred embodiments of the present invention, the polyurethane of the present invention is thermoplastic polyurethane (TPU), and more preferably, the number-average molecular weight of the thermoplastic polyurethane of the present invention is 5,000 to 50,000 g / mol, or its degree of polymerization is 80 to 200. The inventors of the present invention have found that reducing the number-average molecular weight of the thermoplastic polyurethane helps to obtain a system with good implantation performance, ionic conductivity, and battery cycle performance. The inventors of this invention have also discovered that reducing the hard segment content of thermoplastic polyurethane helps to further improve permeability, ionic conductivity, and battery cycle performance. In some preferred embodiments of this invention, the hard segment content of thermoplastic polyurethane does not exceed 30%, more preferably, does not exceed 26%, wherein the hard segment content can be obtained by the following calculation formula: (the sum of the weights of the chain extender and the polyisocyanate reacting with the chain extender) / the total weight of the thermoplastic polyurethane × 100%; or, the hard segment content described in this invention can also be obtained by characterizing the thermoplastic polyurethane using NMR or infrared spectroscopy. Suitable thermoplastic polyurethanes can be made in-house or purchased commercially. Commercially available models include, but are not limited to, Elastollan® SP 9609, Elastollan® SP 9612, Elastollan® 1185A10, Elastollan® 1190A10, Elastollan® 1170 A, Elastollan® SP 1160 A, Elastollan® 1385 A, Elastollan® 1190 A, Elastollan® S80A10, and Elastollan® 3085A10.

[0054] In this invention, the polyurethane content is preferably less than three times the mass of the chemically crosslinkable monomers and / or prepolymers. If the polyurethane content is too high, it may affect curing, and a solid or semi-solid electrolyte cannot be obtained after in-situ polymerization. In some specific embodiments of this invention, based on the total mass of the polymer electrolyte precursor, the polyurethane content is 1.0 wt.% to 20.0 wt.%, for example, 2.0 wt.% to 15.0 wt.%, and further, 4.0 wt.% to 12.0 wt.%.

[0055] Component B)

[0056] Component B) of this invention is a chemically crosslinkable monomer and / or prepolymer. Chemically crosslinkable monomers and / or prepolymers refer to compounds or oligomers containing crosslinkable functional groups (such as acrylates, methacrylates, epoxy groups, or vinyl groups), capable of undergoing free radical polymerization or condensation polymerization under the action of an initiator to form a chemically crosslinked network. Component B) of this invention is used to form a chemically crosslinked network during in-situ polymerization, enhancing the structural stability of the electrolyte and the continuity of ion channels. The chemically crosslinked network of this invention forms a semi-interpenetrating structure with the polyurethane physical network, synergistically improving mechanical properties and ion conduction pathways. Furthermore, the chemically crosslinkable monomers and / or prepolymers, as liquid small molecules, can act as dispersants before polymerization, reducing viscosity, in addition to polymerizing into a crosslinked network. The chemically crosslinkable monomers and / or prepolymers of this invention include one or more compounds selected from the group consisting of:

[0057] 1) Polyfunctional (meth)acrylate monomers or their prepolymers;

[0058] 2) Polyether or epoxy-modified (meth)acrylate compounds;

[0059] 3) Ionic liquid monomers with polymerizable groups;

[0060] And other monomers that optionally have unsaturated double bonds.

[0061] The chemically crosslinkable monomers and / or prepolymers of the present invention may be selected from any one or more compounds listed in 1) to 3) above. The optional addition of other monomers having unsaturated double bonds refers to monomers having unsaturated double bonds that do not belong to categories 1) to 3) above. In some specific embodiments of the present invention, the chemically crosslinkable monomers and / or prepolymers of the present invention include polyfunctional (meth)acrylate monomers or their prepolymers, i.e., (meth)acrylate monomers having two or more acryloyl groups in one molecule, preferably selected from difunctional to hexafunctional (meth)acrylate monomers, with low-degree-of-polymerization intermediates formed by the preliminary polymerization of these monomers serving as their prepolymers. Furthermore, the polyfunctional (meth)acrylate monomers are selected from one or more of the following: diethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, dipropylene glycol diacrylate, dipropylene glycol diacrylate, bis(trimethylolpropane)acrylate, trimethylolpropane trimethacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate, ethoxylated bisphenol A dimethacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate. In some specific embodiments of the present invention, the chemically crosslinkable monomers and / or prepolymers of the present invention include polyether or epoxy-modified (meth)acrylate compounds. Further, the polyether-modified (meth)acrylate compounds are selected from one or more of methoxy polyethylene glycol methacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, polypropylene glycol diacrylate, and polypropylene glycol dimethacrylate; the epoxy-modified (meth)acrylate compounds are selected from one or more of glycidyl methacrylate and glycidyl acrylate. In the present invention, polyether-modified multifunctional (meth)acrylate compounds belong to category 2). In other specific embodiments of the present invention, the chemically crosslinkable monomers and / or prepolymers of the present invention comprise ionic liquid monomers having polymerizable groups. Further, the polymerizable groups comprise one or more of vinyl, allyl, acrylate, and methacrylate groups. More further, the ionic liquid monomers having polymerizable groups comprise cations selected from at least one of the following: ammonium cations, pyrrolidine cations, pyridinium cations, pyrimidine cations, imidazole cations, piperidinium cations, pyrazolium cations, oxazolium cations, pyridazine cations, phosphonium cations, sulfonium cations, triazolium cations, and at least one of the following anions: BF4. - PF6 - AsF6 -, SbF6 - , AlCl4 - , HSO4 - , ClO4 - , CH3SO3 - , CF3CO2 - , (CF3SO2)2N - , (FSO2)2N - , Cl - , Br - , I - , SO4 2- , CF3SO3 - , (C2F5SO2)2N - , NO3 - , Al2Cl7 - , (CF3SO2)3C - , (CF3)3PF3 - , (CF3)4PF2 - , (CF3)5PF - , (CF3)6P - , SF5CF2SO3 - , (C2F5SO2)(CF3SO2) N - , SF5CHFCF2SO3 - , CF3CF2(CF3)2CO - , (CF3SO2)2CH - , (SF5)3C - and (O(CF3)2C2(CF3)2O)2PO -In other embodiments of the invention, the other monomers optionally having unsaturated double bonds are selected from one or more combinations of (meth)acrylate C1-C12 alkyl esters, (meth)acrylamide, and ethylene carbonate. For higher ionic conductivity, preferably, the chemically crosslinkable monomers and / or prepolymers of the invention are ionic liquid monomers with polymerizable groups and / or polyether-modified (meth)acrylate compounds and optionally include other monomers having unsaturated double bonds. Specifically, the chemically crosslinkable monomers and / or prepolymers of the present invention are preferably selected from one or more of 1-vinyl-3-butylimidazolium trifluoromethanesulfonylimide, methoxy polyethylene glycol methacrylate (mPEGMA), polyethylene glycol diacrylate (PEGDA), triethylene glycol dimethacrylate (TEGDA), ethoxylated trimethylolpropane triacrylate (ETPTA), bis(trimethylolpropane) acrylate, pentaerythritol triacrylate, and ethylene ethylene carbonate. More preferably, the chemically crosslinkable monomers and / or prepolymers of the present invention are selected from 1-vinyl-3-butylimidazolium trifluoromethanesulfonylimide, methoxy polyethylene glycol methacrylate (mPEGMA), and / or polyethylene glycol diacrylate (PEGDA). All of the above monomers and / or prepolymers are commercially available.

[0062] The inventors of this invention have discovered that increasing the concentration of chemically crosslinkable monomers and / or prepolymers increases the degree of crosslinking, which may lead to inhibition of ion conduction. In some specific embodiments of this invention, to balance curing performance, injection performance, and overall battery performance, the sum of the contents of chemically crosslinkable monomers and / or prepolymers and polyurethane, based on the total mass of the polymer electrolyte precursor, is preferably 1 wt.% to 35 wt.%, for example 5 wt.%, 7 wt.%, 11 wt.%, 13 wt.%, 15 wt.%, 19 wt.%, 21 wt.%, 25 wt.%, 29 wt.%, 30 wt.%, preferably 3 wt.% to 30 wt.%, and more preferably 7 wt.% to 25 wt.%.

[0063] Component C)

[0064] Component C) of this invention is a lithium salt. The lithium salt provides lithium ions (Li... +The lithium salt is a key component for lithium-ion conduction. The lithium salt is dissolved in the electrolyte solvent to obtain the electrolyte, providing mobile lithium ions to achieve ion conduction and electrochemical reactions in the battery. This invention does not have specific requirements for the type of lithium salt; the lithium salt can be selected from one or more combinations of lithium hexafluorophosphate, lithium bis(oxalato)borate, lithium difluorooxalato)borate, lithium tetrafluoroborate, lithium hexafluoroantimonyate, lithium hexafluoroarsenate, lithium perfluorobutylsulfonate, lithium perchlorate, lithium aluminate, lithium tetrachloroaluminate, lithium trifluoromethanesulfonate, lithium bis(sulfonyl)imide, lithium bis(sulfonyl)imide, lithium bis(trifluoromethanesulfonate)imide, lithium chloride, and lithium fluoride. Preferably, to obtain high ionic conductivity and good stability, the lithium salt is selected from one or more of lithium hexafluorophosphate (LiPF6), lithium hexafluoroarsenate (LiAsF6), lithium perchlorate (LiClO4), lithium bis(trifluoromethanesulfonate)imide (LiTFSI), lithium tetrafluoroborate (LiBF4), lithium trifluoromethanesulfonate (LiCF3SO3), lithium bis(trifluoromethanesulfonate)imide (LiN(CF3SO2)2), lithium bis(fluorosulfonylimide) (LiFSI), and lithium hexafluoroantimonylate (LiSBF6). Lithium salts are commercially available and are typically used in powder form.

[0065] In some specific embodiments of the present invention, based on the total mass of the polymer electrolyte precursor, the lithium salt content is 5 wt.% to 30 wt.%, preferably 7 wt.% to 20 wt.%, such as 7 wt.%, 8 wt.%, 9 wt.%, 10 wt.%, 12 wt.%, 14 wt.%, 15 wt.%, 18 wt.%, and more preferably 8 wt.% to 16 wt.%. Excessive concentration may lead to increased viscosity, while insufficient concentration may result in inadequate ionic conductivity.

[0066] Component D)

[0067] Component D) of this invention is an initiator. An initiator is a compound that can generate free radicals or active species under thermal or light conditions, initiating a chemical crosslinking reaction. The initiator of this invention is preferably a thermal initiator. In in-situ polymerization, the initiator of this invention can initiate the polymerization reaction of chemically crosslinkable monomers or prepolymers, forming a stable chemical crosslinking network, which helps to solidify the electrolyte and improve mechanical strength and cycle stability. In some specific embodiments of this invention, the initiator is selected from one or more combinations of azobisisobutyronitrile (AIBN), azobisisovalerate (ABVN), azobisisoheptanenitrile (ADVN), benzoyl peroxide (BPO), and potassium persulfate.

[0068] In some specific embodiments of the present invention, the initiator content is 0.2 wt.% to 2.0 wt.% of the mass of the chemically crosslinkable monomer and / or prepolymer of B), preferably 0.5 wt.% to 1.5 wt.%.

[0069] Component E)

[0070] Component E) of this invention is an electrolyte solvent. The electrolyte solvent is a liquid medium that dissolves lithium salts and other electrolyte components, and is typically an organic solvent. In some specific embodiments of this invention, the electrolyte solvent includes carbonate solvents, such as mixed solvents of cyclic carbonates and linear carbonates. Representative examples of cyclic carbonates include ethylene carbonate (EC) or propylene carbonate (PC), and representative examples of linear carbonates include dimethyl carbonate (DMC), diethyl carbonate (DEC), and ethyl methyl carbonate (EMC). Cyclic carbonates such as ethylene carbonate (EC) and propylene carbonate (PC) are characterized by high dielectric constant, strong solvation ability, and high viscosity. Linear carbonates such as dimethyl carbonate (DMC), diethyl carbonate (DEC), and ethyl methyl carbonate (EMC) are characterized by low viscosity, good diffusion, low melting point, and low dielectric constant. A mixed solvent of two types of carbonates in a proportional ratio, such as equal volumes of EC, EMC, and DMC, exhibits both high dielectric constant and low viscosity. In some specific embodiments of the present invention, the electrolyte solvent, in addition to carbonate solvents, may include one or more other commonly used electrolyte solvents such as ether solvents and sulfone solvents. The ethers may be cyclic ethers or straight-chain ethers. Cyclic ethers may be tetrahydrofuran (THF) and / or 2-methyltetrahydrofuran. Straight-chain ethers may be selected from dimethoxyethane (DME), ethylene glycol dimethyl ether, triethylene glycol dimethyl ether (TEDGE), tetraethylene glycol dimethyl ether (TEDGE), and mixtures thereof. Sulfone solvents, such as dimethyl sulfoxide (DMSO), are used to adjust solubility and stability. Preferably, the electrolyte solvent of the present invention is selected from carbonate solvents, i.e., excluding other types of electrolyte solvents or other common organic solvents that can dissolve polyurethane and require removal in subsequent processes, such as N,N-dimethylformamide (DMF), to further simplify the system composition and improve safety and process compatibility. The inventors of the present invention have also discovered that carbonate solvents in the present invention can act as both solvents and plasticizers, serving as a medium for ion migration and enhancing the flexibility of the polyurethane chain, thereby improving ionic conductivity. Furthermore, it helps to ensure uniform dispersion of the components, guaranteeing low viscosity and small particle size of the precursor. The electrolyte solvent can be obtained from battery-grade solvent suppliers.

[0071] The content of the electrolyte solvent can be adjusted according to actual needs to ensure sufficient solubility and flowability. In some specific embodiments of the present invention, based on the total mass of the polymer electrolyte precursor, the content of the electrolyte solvent is 40 wt.% to 80 wt.%, more preferably 45 wt.% to 75 wt.%.

[0072] In addition to the components described above, the polymer electrolyte precursor of the present invention may also include optional additives (F) that can improve battery performance and safety. These additives are selected from one or more of inorganic nanoparticles, inorganic solid electrolyte particles, and ionic liquids. In this invention, the ionic liquid used as an additive differs from the ionic liquid monomer and does not have polymerizable groups. Preferably, the total content of the additives is from 0.1 wt.% to 15 wt.% of the total mass of the polymer electrolyte precursor, more preferably from 0.5 wt.% to 8 wt.%. Preferably, the inorganic nanoparticles are selected from one or more of Al2O3, SiO2, ZnO, TiO2, ZrO2, Ga2O3, In2O3, GeO2, Nb2O5, SiC, MgS, and CaS; preferably, the inorganic solid electrolyte particles are selected from one or more of garnet-type lithium lanthanum zirconium oxide (LLZO), perovskite-type lithium lanthanum titanium oxide (LLTO), NASICON-type lithium aluminum titanium phosphorus oxide (LATP), and LISICON-type lithium aluminum germanium phosphorus oxide (LAGP); the average particle size of the inorganic solid electrolyte particles is 0.1 μm to 5 μm. Preferably, the ionic liquid is selected from one or more of imidazole ionic liquids, pyrrolidine ionic liquids, pyridine ionic liquids, quaternary ammonium salt ionic liquids, alkenyl functionalized ionic liquids, and sulfonic acid functionalized ionic liquids; more preferably, the cation of the ionic liquid is one of 1-ethyl-3-methylimidazolium, 1-butyl-3-methylimidazolium, and N-butyl-N-methylpyrrolidineonium, and the anion is one of bis(trifluoromethanesulfonyl)imide, hexafluorophosphate, and tetrafluoroborate. By introducing the above additives, the electrochemical stability window, ionic conductivity, lithium-ion transference number, mechanical strength, and interfacial compatibility with electrode materials of the final polymer electrolyte can be effectively improved.

[0073] To achieve good injection performance and ensure the battery's electrical performance, the polyurethane of this invention needs to be dissolved or dispersed in the polymer electrolyte precursor at room temperature. Preferably, the polyurethane of this invention is completely dissolved in the polymer electrolyte precursor at room temperature, and the viscosity of the polymer electrolyte precursor, measured at 25°C, is not higher than 400 cP. This characteristic ensures that the precursor can flow smoothly into the electrode and separator pores during battery assembly, avoiding blockage of the injection channels and achieving uniform electrolyte distribution, thereby improving the battery's interfacial contact and electrochemical stability. A preferred viscosity range is not higher than 250 cP, for example, 0-200 cP, more preferably 0-60 cP, to maximize flowability while maintaining sufficient ionic conductivity. Preferably, when the polyurethane is dispersed in the polymer electrolyte precursor, the average particle size measured by laser diffraction (LD) at 25°C is less than 5 micrometers, more preferably not more than 2 micrometers, and even more preferably, the average particle size (Z-average diameter) of the polymer electrolyte precursor of the present invention measured by laser diffraction at 25°C is not more than 1 micrometer, more preferably not greater than 60 nm, to enhance dispersion stability and reduce interfacial impedance. To achieve the above viscosity and particle size control, the present invention can employ one or more technical means for adjustment, including but not limited to: optimizing the polyurethane structure, selecting thermoplastic polyurethane (TPU) with lower molecular weight and lower degree of polymerization, and controlling the polyurethane concentration; adjusting the crosslinking monomer ratio: by controlling the type and ratio of chemically crosslinkable monomers and / or prepolymers, the degree of polymerization and particle formation process of the system can be adjusted, affecting the final particle size and rheological properties; using low-viscosity solvents; and optimizing mixing conditions, introducing mechanical dispersion methods during the preparation process, such as high-speed shearing or ultrasonic treatment, which can effectively reduce particle agglomeration and obtain a more uniform nanoscale particle distribution, etc. Through the synergistic regulation of the above methods, the polymer electrolyte precursor of the present invention can achieve excellent injectability while maintaining good electrochemical performance, thereby improving the efficiency of battery manufacturing and making it suitable for the large-scale preparation of in-situ polymerized solid-state batteries or semi-solid-state batteries.

[0074] Preparation method of polymer electrolyte precursor

[0075] The present invention also provides a method for preparing the polymer electrolyte precursor of the present invention, comprising: dissolving or dispersing polyurethane in an electrolyte solvent, adding a chemically crosslinkable monomer and / or prepolymer and an initiator and a lithium salt, and stirring to obtain the polymer electrolyte precursor of the present invention; or, dissolving or dispersing polyurethane in an electrolyte solvent and an electrolyte containing a lithium salt, adding a chemically crosslinkable monomer and / or prepolymer and an initiator, and stirring to obtain the polymer electrolyte precursor of the present invention.

[0076] The main difference between the two methods lies in the order of lithium salt addition and the composition of the solvent system. In the first method, polyurethane is first dissolved in a lithium-free electrolyte solvent to obtain a pre-prepared polyurethane solution or dispersion, followed by the addition of lithium salt. This method focuses on controlling the dissolution / dispersion of polyurethane and the formation of a physical cross-linking network. The second method, however, can be based on existing liquid electrolytes, directly dissolving polyurethane in a lithium-containing liquid electrolyte. This method simplifies the operation steps and is suitable for rapid preparation and large-scale production. Depending on the actual storage or field requirements, those skilled in the art can choose a suitable precursor preparation method.

[0077] In some specific embodiments of the present invention, the stirring temperature of polyurethane in the electrolyte solvent or the lithium salt-containing liquid electrolyte is 25°C to 80°C, preferably 25°C to 45°C.

[0078] In other specific embodiments of the present invention, the polyurethane of the present invention can be pre-prepared polyurethane particles or sheet materials (such as thermoplastic polyurethane particles), or it can be directly synthesized in an electrolyte solvent via in-situ polymerization. For example, a component comprising a polyol with an average functionality of 1.8 to 2.2 and an isocyanate with an average functionality of 1.8 to 2.2 are added to an electrolyte solvent, and the mixture is stirred and reacted at a suitable reaction temperature to form a polyurethane network. Then, a chemically crosslinkable monomer and / or prepolymer, an initiator, and a lithium salt are added, and the mixture is stirred to obtain the polymer electrolyte precursor of the present invention. In-situ polymerization can enhance compatibility with the electrolyte, reduce the risk of phase separation, and help prepare polymer electrolyte precursors with lower viscosity and smaller particle size.

[0079] This preparation method has the advantages of simple operation, stable system, strong adaptability, low energy consumption and low cost. It realizes the controllable preparation of polymer electrolyte precursors, is applicable to the manufacturing process of various solid-state or semi-solid-state batteries, and has good prospects for industrialization.

[0080] Polymer electrolyte

[0081] This invention also provides a polymer electrolyte, which is obtained by in-situ polymerization of the polymer electrolyte precursor of this invention or the polymer electrolyte precursor obtained according to the aforementioned preparation method of this invention by injecting it into a battery. In some specific embodiments of this invention, the electrolyte precursor is injected into a battery structure (such as a laminate composed of a positive electrode, a negative electrode, and a separator) and a polymerization reaction is initiated under specific conditions (preferably heating) to form a stable electrolyte layer. Depending on the ratio of polyurethane to chemically crosslinkable monomers and / or prepolymers, and the amount of chemically crosslinkable monomers and / or prepolymers used, the final polymer electrolyte may exhibit a completely solid or semi-solid morphology (such as a gel or semi-fluid state). A completely solid state is beneficial for improving flame retardant performance, while a gel or semi-fluid state, due to retaining certain liquid characteristics, is beneficial for improving interfacial wettability and ionic conductivity.

[0082] Regardless of whether it is in solid or semi-solid form, the polymer electrolyte of the present invention possesses a semi-interpenetrating polymer network (semi-IPN) structure. This structure is composed of nested networks formed by the polymerization of physically cross-linked polyurethane and chemically cross-linked monomers and / or prepolymers. The physical network provides flexibility and interfacial adaptability, while the chemical network imparts good mechanical strength and thermal stability to the system. The synergistic effect of both allows the polymer electrolyte to maintain high ionic conductivity while possessing excellent mechanical properties and interfacial stability.

[0083] In some preferred embodiments of the present invention, the formation process of the polymer electrolyte includes the following steps: injecting the precursor into the dry cell, followed by heating for in-situ polymerization, preferably at a temperature of 25°C to 60°C, for a polymerization time of 10 minutes to 24 hours, and finally forming a stable polymer electrolyte structure.

[0084] This invention achieves high-performance and controllable preparation of electrolytes through in-situ polymerization and semi-interpenetrating network design, providing a reliable solution for next-generation battery technology. This structural design is applicable not only to the manufacture of in-situ injected solid-state batteries but also to semi-solid-state battery systems requiring high-rate charge-discharge, exhibiting good process compatibility and application scalability.

[0085] Preparation methods of solid-state batteries or semi-solid-state batteries

[0086] This invention also provides a method for preparing a solid-state battery or a semi-solid-state battery, which includes two methods:

[0087] 1) Dry cell injection method, which involves the following steps:

[0088] Step i: Inject the polymer electrolyte precursor of the present invention or the polymer electrolyte precursor prepared according to the method described above into the dry cell;

[0089] The polymer electrolyte precursor of the present invention is injected into a pre-assembled dry cell, which is typically composed of a cathode, an anode, and a separator stacked or wound together without any liquid electrolyte injected. In some preferred embodiments of the present invention, the precursor solution is injected into the dry cell at a rate of 2-5 g / Ah, and allowed to stand, allowing the precursor to automatically wet the pores through capillary action. The present invention does not impose any particular limitations on the types of electrodes and separators. In some specific embodiments of the present invention, the cathode material can be selected from one or more of lithium manganese oxide (LMO), lithium cobalt oxide (LCO), lithium nickel manganese cobalt oxide (NMC), or lithium iron phosphate (LFP); the anode material may include carbon black, carbon nanotubes, lithium metal, graphene, or graphite; the separator is a porous separator with a porosity preferably of 30% to 60%, and the separator material may be selected from polyolefins (such as polyethylene PE or polypropylene PP), ceramic-coated separators, or non-woven separators (such as polyimide-based separators) with a thickness of 10-25 μm. High porosity ensures smooth precursor penetration while maintaining mechanical strength.

[0090] The goal of this step is to achieve a uniform distribution of the precursor within the battery cell. To improve the wetting effect of the precursor, vacuum treatment can be used to allow the precursor solution to fully penetrate into the microporous structure of the electrode material, thereby enhancing interfacial contact and ion transport efficiency.

[0091] Step ii: In-situ polymerization by heating

[0092] After injection, the battery cell is placed under certain temperature conditions for in-situ polymerization to form a solid or semi-solid electrolyte. In some specific embodiments of the present invention, the in-situ polymerization temperature range is 25℃~100℃, preferably 25℃~60℃, and the polymerization time is 10 minutes~24 hours.

[0093] The formation treatment can be performed before or after in-situ polymerization to optimize the electrode interface. In some specific embodiments of the present invention, the formation temperature is 25°C to 120°C, preferably 25°C to 50°C. During the formation process, a small current (e.g., 0.05C) is applied for charge-discharge cycling to form a stable solid electrolyte interphase (SEI) film on the electrode surface.

[0094] Step iii: Sealing

[0095] After polymerization, the battery casing is sealed to protect internal components and prevent environmental contaminants from entering. Sealing methods include, but are limited to, sealing the battery casing using laser welding, heat sealing, or mechanical pressing (such as aluminum-plastic film or metal cans).

[0096] In addition to the dry cell injection method, the method for preparing solid-state or semi-solid-state batteries according to the present invention also includes pre-coating the precursor solution of the present invention onto the electrode and separator surfaces (coating thickness 50-100 μm), allowing it to stand, and then directly curing it on the electrode / separator surface by thermal initiation, and then directly obtaining the corresponding solid-state or semi-solid-state battery by lamination or winding.

[0097] Both of the above-mentioned preparation methods of the present invention are simple and cost-controllable, and also help to achieve high ionic conductivity, excellent interfacial contact and long-term cycle stability of the battery.

[0098] Solid-state or semi-solid-state batteries and electrical devices

[0099] This invention also provides a solid-state battery or a semi-solid-state battery, which includes the polymer electrolyte described above, or is prepared by the method for preparing a solid-state battery or a semi-solid-state battery described above. The solid-state battery or semi-solid-state battery of this invention achieves high energy density, excellent safety, and long cycle life by integrating a high-performance polymer electrolyte, making it suitable for various electrical devices, such as electric vehicles, wearable electronic devices, and energy storage systems.

[0100] The following embodiments are provided to illustrate the invention in more detail.

[0101] Implementation Plan 1

[0102] A polymer electrolyte precursor for preparing solid-state or semi-solid-state batteries, the precursor comprising:

[0103] A) Polyurethane;

[0104] B) Chemically crosslinkable monomers and / or prepolymers;

[0105] C) Lithium salts;

[0106] D) Initiator;

[0107] E) Electrolyte solvent;

[0108] F) Optional additives;

[0109] The polyurethane is prepared by reacting a polyol with an average functionality of 1.8 to 2.2, an isocyanate with an average functionality of 1.8 to 2.2, a chain extender, and optional additives. The polyurethane is dissolved or dispersed in the polymer electrolyte precursor at 25°C, and the viscosity of the polymer electrolyte precursor measured at 25°C is not higher than 400 cP.

[0110] Implementation Plan 2

[0111] According to the polymer electrolyte precursor of the first embodiment, wherein...

[0112] The polyurethane has a number-average molecular weight of less than 100,000 g / mol, preferably less than 60,000 g / mol, and more preferably, the polyurethane is a thermoplastic polyurethane with a number-average molecular weight of 5,000 to 50,000 g / mol.

[0113] Implementation Plan 3

[0114] According to the polymer electrolyte precursor of the second embodiment, wherein...

[0115] The polyol is a polyether alcohol containing an ether oxygen bond.

[0116] Implementation Plan 4

[0117] According to any one of the embodiments 1 to 3, the polymer electrolyte precursor, wherein...

[0118] The chemically crosslinkable monomers and / or prepolymers mentioned in B) include one or more compounds selected from the group consisting of:

[0119] 1) Polyfunctional (meth)acrylate monomers or their prepolymers;

[0120] 2) Polyether or epoxy-modified (meth)acrylate compounds;

[0121] 3) Ionic liquid monomers with polymerizable groups;

[0122] And other monomers that optionally have unsaturated double bonds.

[0123] Implementation Plan 5

[0124] According to the polymer electrolyte precursor of the fourth embodiment, wherein...

[0125] The polymerizable groups of the ionic liquid monomer having polymerizable groups include one or more of vinyl, allyl, acrylate, and methacrylate groups. The ionic liquid monomer having polymerizable groups includes a cation selected from at least one of the following: ammonium cation, pyrrolidineonium cation, pyridinium cation, pyrimidineonium ion, imidazoleonium cation, piperidinium cation, pyrazolium cation, oxazolium cation, pyridazineonium cation, phosphonium cation, sulfonium cation, triazolium cation, and an anion selected from at least one of the following: BF4. - PF6 - AsF6 - SbF6 - AlCl4 - HSO4 - ClO4 - CH3SO3- CF3CO2 - (CF3SO2)2N - (FSO2)2N - Cl - ,Br - I - SO4 2- CF3SO3 - (C2F5SO2)2N - NO3 - Al2Cl7 - (CF3SO2)3C - (CF3)3PF3 - (CF3)4PF2 - (CF3)5PF - (CF3)6P - SF5CF2SO3 - (C2F5SO2)(CF3SO2)N - SF5CHFCF2SO3 - CF3CF2(CF3)2CO - (CF3SO2)2CH - (SF5)3C - and (O(CF3)2C2(CF3)2O)2PO - .

[0126] Implementation Plan 6

[0127] According to any one of embodiments 1 to 5, the polymer electrolyte precursor, wherein,

[0128] The chemically crosslinkable monomers and / or prepolymers in B) are selected from methoxylated polyethylene glycol methacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, polypropylene glycol diacrylate, polypropylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, dipropylene glycol diacrylate, dipropylene glycol diacrylate, dipropylene glycol diacrylate, bis(trimethylolpropane) acrylate, trimethylolpropane trimethacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate, ethoxylated bisphenol A dimethacrylate, 1,4-butanediol diacrylate, 1 The monomers are selected from one or more of the following: 6-hexanediol diacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, glycidyl acrylate, and glycidyl methacrylate; the other monomers optionally having unsaturated double bonds are selected from one or more combinations of C1-C12 alkyl acrylates, C1-C12 alkyl methacrylates, methacrylamide, acrylamide, and ethylene carbonate.

[0129] Implementation Plan No. 7

[0130] According to any of the embodiments 1 to 6, the polymer electrolyte precursor, wherein,

[0131] The sum of the contents of A) polyurethane and B) chemically crosslinkable monomers and / or prepolymers accounts for 1 wt.% to 35 wt.%, preferably 7 wt.% to 25 wt.%, of the total mass of the polymer electrolyte precursor.

[0132] Implementation Plan No. 8

[0133] According to any of the embodiments 1 to 7, the polymer electrolyte precursor, wherein,

[0134] The mass of A) polyurethane is less than 3 times the mass of B) chemically crosslinkable monomers and / or prepolymers.

[0135] Implementation Plan No. 9

[0136] According to any of the embodiments 1 to 8, the polymer electrolyte precursor, wherein,

[0137] The lithium salt in C) is selected from one or more combinations of lithium hexafluorophosphate, lithium bis(oxalato)borate, lithium difluorooxalato)borate, lithium tetrafluoroborate, lithium hexafluoroantimonyate, lithium hexafluoroarsenate, lithium perfluorobutyl sulfonate, lithium perchlorate, lithium aluminate, lithium tetrachloroaluminate, lithium trifluoromethanesulfonate, lithium bis(sulfonyl)imide, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonate)imide, lithium chloride, and lithium fluoride.

[0138] Implementation Plan No. 10

[0139] According to any of the embodiments 1 to 9, the polymer electrolyte precursor, wherein,

[0140] The content of lithium salt in C) accounts for 5 wt.% to 30 wt.% of the total mass of the polymer electrolyte precursor, preferably 7 wt.% to 20 wt.%.

[0141] Implementation Plan No. 11

[0142] The polymer electrolyte precursor according to any one of embodiments 1 to 10, wherein,

[0143] The content of the initiator in D) is 0.2 wt.% to 2 wt.% of the mass of the chemically crosslinkable monomer and / or prepolymer in B).

[0144] Implementation Plan No. 12

[0145] The polymer electrolyte precursor according to any of embodiments 1 to 11, wherein,

[0146] The electrolyte solvent in E) is selected from carbonate solvents, preferably ethylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, or mixtures thereof.

[0147] Implementation Plan No. 13

[0148] The polymer electrolyte precursor according to any of embodiments 1 to 12, wherein,

[0149] When the polyurethane is dispersed in the polymer electrolyte precursor, the average particle size, as determined by laser diffraction at 25°C, is less than 5 micrometers, preferably not more than 2 micrometers, and more preferably not more than 1 micrometer.

[0150] Implementation Plan 14

[0151] According to any of the embodiments 1 to 13, the polymer electrolyte precursor, wherein...

[0152] The polymer electrolyte precursor further comprises additives selected from one or more of inorganic nanoparticles, inorganic solid electrolyte particles, and ionic liquids; preferably, the total content of the additives accounts for 0.1 wt.% to 15 wt.% of the total mass of the polymer electrolyte precursor; preferably, the inorganic nanoparticles are selected from one or more of Al2O3, SiO2, ZnO, TiO2, ZrO2, Ga2O3, In2O3, GeO2, Nb2O5, SiC, MgS, and CaS; preferably, the inorganic solid electrolyte particles are selected from garnet-type lithium lanthanum zirconium oxide (LLZO), perovskite-type lithium lanthanum titanium oxide (LLTO), NASICON-type lithium aluminum titanium phosphorus oxide (LATP), and LISICON-type lithium aluminum germanium phosphorus oxide (LAGP). One or more of the following: preferably, the ionic liquid is selected from one or more of imidazole ionic liquids, pyrrolidine ionic liquids, pyridine ionic liquids, quaternary ammonium salt ionic liquids, alkenyl functionalized ionic liquids, and sulfonic acid functionalized ionic liquids; more preferably, the cation of the ionic liquid is one of 1-ethyl-3-methylimidazolium, 1-butyl-3-methylimidazolium, and N-butyl-N-methylpyrrolidineonium, and the anion is one of bis(trifluoromethanesulfonyl)imide, hexafluorophosphate, and tetrafluoroborate.

[0153] Implementation Plan No. 15

[0154] A method for preparing a polymer electrolyte precursor as described in any of embodiments 1 to 14, wherein,

[0155] Polyurethane is dissolved or dispersed in an electrolyte solvent, and chemically crosslinkable monomers and / or prepolymers and initiators and lithium salts are added and stirred to obtain the polymer electrolyte precursor described in any of the embodiments 1 to 14.

[0156] or,

[0157] Polyurethane is dissolved or dispersed in an electrolyte solvent and a lithium salt electrolyte, and chemically crosslinkable monomers and / or prepolymers and initiators are added and stirred to obtain the polymer electrolyte precursor described in any of embodiments 1 to 14.

[0158] Implementation Plan No. 16

[0159] According to the method of the 15th embodiment, wherein,

[0160] The polyurethane is in granular or sheet form.

[0161] Implementation Plan No. 17

[0162] According to the method of the 15th embodiment, wherein,

[0163] The polyurethane is obtained by mixing a polyol component with an average functionality of 1.8 to 2.2 and an isocyanate component with an average functionality of 1.8 to 2.2, and polymerizing them in situ in the electrolyte solvent or the electrolyte.

[0164] Implementation Plan No. 18

[0165] A polymer electrolyte, wherein the polymer electrolyte precursor described in any of embodiments 1 to 14 or the polymer electrolyte precursor prepared according to any of embodiments 15 to 17 is injected into a battery and polymerized in situ.

[0166] Implementation Plan No. 19

[0167] The polymer electrolyte according to embodiment 18, wherein,

[0168] The polymer electrolyte comprises a semi-interpenetrating polymer network, which includes polyurethane and chemically crosslinked products formed by the polymerization of chemically crosslinkable monomers and / or prepolymers.

[0169] Implementation Plan No. 20

[0170] A method for preparing a solid-state battery or a semi-solid-state battery, wherein,

[0171] The method includes the following steps:

[0172] Step i: Inject the polymer electrolyte precursor as described in any of embodiments 1 to 14 or the polymer electrolyte precursor prepared according to the method described in any of embodiments 15 to 17 into the dry cell;

[0173] Step ii: In-situ polymerization is carried out by heating;

[0174] Step iii: Seal;

[0175] or,

[0176] The method includes pre-coating the polymer electrolyte precursor of any of embodiments 1 to 14 or the polymer electrolyte precursor prepared according to any of embodiments 15 to 17 onto the surface of the electrode and / or separator, heating to perform in-situ polymerization to solidify it on the surface of the electrode and / or separator, and then obtaining a solid-state battery or a semi-solid-state battery by lamination or winding.

[0177] Implementation Plan No. 21

[0178] The method for preparing a solid-state battery or semi-solid-state battery according to embodiment 20, wherein,

[0179] The in-situ polymerization temperature is 25℃~100℃, preferably 25℃~60℃, and the in-situ polymerization time is 10 minutes~24 hours.

[0180] Implementation Plan No. 22

[0181] The method for preparing a solid-state battery or semi-solid-state battery according to embodiment 20 or 21, wherein,

[0182] The method further includes a formation step, wherein the formation temperature is 25℃~120℃, preferably 25℃~50℃.

[0183] Implementation Plan No. 23

[0184] A solid-state battery or semi-solid-state battery, wherein it comprises a polymer electrolyte as described in embodiment 18 or 19, or is prepared by a method for preparing a solid-state battery or semi-solid-state battery as described in any of embodiments 20 to 22.

[0185] Implementation Plan No. 24

[0186] An application of a solid-state battery or semi-solid-state battery according to embodiment 23 in an electrical device, wherein the electrical device contains the solid-state battery or semi-solid-state battery according to embodiment 23.

[0187] The present invention will be explained in more detail below with reference to embodiments and comparative examples, and it should be understood that the present invention is not limited to these embodiments.

[0188] Material

[0189] Table 1

[0190]

[0191] Test methods

[0192] Viscosity: An ASTM D2196 rotational viscometer with a No. 2 rotor was used. At room temperature (25°C), after leveling the viscometer, the rotor was immersed in the obtained precursor solution until it exceeded the graduation mark. The rotation speed was set to 60 rpm, and the reading was taken after stabilization. It was ensured that the torque was within the effective reading range of 10-90%.

[0193] Particle size: The refractive index and viscosity of the precursor solution are obtained by laser diffraction, and the average particle size (Z-average diameter) is obtained by software data processing.

[0194] Linear sweep voltammetry (LSV) curves: The obtained precursor solution was injected into a coin cell, with a lithium metal sheet as the working electrode and a stainless steel sheet as the counter electrode. After thermally initiated in-situ polymerization of the assembled coin cell, the linear sweep voltammetry performance of the polymer electrolytes obtained from different polymer matrices was tested. The scan rate was 0.1 mV / s, and the scan potential range was 2 V-5.5 V.

[0195] Room temperature ionic conductivity: Ionic conductivity was tested using electrochemical impedance spectroscopy (EIS) with a barrier electrode structure (stainless steel / electrolyte / stainless steel). The obtained precursor solution was dropped onto the PP separator between the two stainless steel electrodes, ensuring good contact between the two electrodes. After assembling the coin cell, the cell was heated at 60°C for 24 hours for in-situ polymerization. After polymerization, the temperature was lowered to room temperature (25°C) for testing. A small AC voltage (between ±5mV and ±20mV) was applied to both sides of the cell, with a scanning frequency range of 10. 6 -10 -1 Hz. The resistance R at the intersection of the high-frequency end and the real axis is obtained by measuring the impedance spectrum. The ionic conductivity is calculated according to the formula σ=L / (RA), where L is the electrolyte thickness (measured using a micrometer) and A is the effective area of ​​the electrode.

[0196] Battery cycle test: At room temperature, for batteries with lithium iron phosphate cathodes, charge at a constant current of 0.5C to the charging cutoff voltage of 4V, rest for 5 minutes, discharge at a constant current of 0.5C to 2V, then rest for 5 minutes, and repeat this cycle. Capacity retention rate after 100 cycles = (100th discharge capacity / first discharge capacity) × 100%.

[0197] Preparation and performance testing of polymer electrolyte precursors

[0198] Examples 1-13

[0199] According to the component measurements in Table 3 (where the amounts refer to parts by weight), PU1-PU5 particles were added to the electrolyte, which consisted of electrolyte solvents namely ethylene carbonate (EC), ethyl methyl carbonate (EMC), dimethyl carbonate (DMC) 1 / 1 / 1 (v / v / v), and LiPF6, with LiPF6 accounting for 12.5 wt.% of the electrolyte mass. The mixture was stirred at 50°C for 24 hours. Subsequently, chemically crosslinkable monomers and / or prepolymers were added, including azoisobutyronitrile (AIBN) at a mass of 1 wt.% of the chemically crosslinkable monomers and / or prepolymers. The mixture was stirred and homogenized at room temperature to obtain the polymer electrolyte precursors (E1-E13).

[0200] The viscosity and particle size of the prepared polymer electrolyte precursor and the ionic conductivity of the polymer electrolyte obtained from the polymer electrolyte precursor were tested respectively, and the results are shown in Table 3.

[0201] Example 14

[0202] Following the component metering of Example 1, PU1 particles were added to an electrolyte solvent of ethylene carbonate (EC), ethyl methyl carbonate (EMC), and dimethyl carbonate (DMC) in a 1 / 1 / 1 (v / v / v) ratio, and stirred at 50°C for 24 hours. Subsequently, LiPF6, chemically crosslinkable monomers and / or prepolymers were added, along with azoisobutyronitrile (AIBN) at an amount of 1 wt.% of the chemically crosslinkable monomers and / or prepolymers. The mixture was stirred and homogenized at room temperature to obtain the polymer electrolyte precursor (E14).

[0203] The viscosity and particle size of the prepared polymer electrolyte precursor and the ionic conductivity of the polymer electrolyte obtained from the polymer electrolyte precursor were tested, and the results are shown in Table 3.

[0204] Example 15

[0205] According to the component measurements in Table 3, an electrolyte consisting of ethylene carbonate (EC), ethyl methyl carbonate (EMC), dimethyl carbonate (DMC) 1 / 1 / 1 (v / v / v) and LiPF6 was added to a container. Polyurethane raw materials (2.61 parts by weight of polytetrahydrofuran glycol with a number average molecular weight of 1000 g / mol, 2.61 parts by weight of polytetrahydrofuran glycol with a number average molecular weight of 2000 g / mol, 0.35 parts by weight of 1,4-butanediol, and 1.93 parts by weight of 4,4'-diphenylmethane diisocyanate) were added sequentially. The mixture was stirred, and the reaction temperature was controlled to not exceed 60°C, allowing the polyurethane raw materials to polymerize in situ in the electrolyte. After 15 minutes, chemically crosslinkable monomers and / or prepolymers were added, including azoisobutyronitrile (AIBN) at 1 wt.% of the chemically crosslinkable monomers and / or prepolymers. The mixture was stirred and homogenized at room temperature to obtain the polymer electrolyte precursor (E15).

[0206] The viscosity and particle size of the prepared polymer electrolyte precursor and the ionic conductivity of the polymer electrolyte obtained from the polymer electrolyte precursor were tested, and the results are shown in Table 3.

[0207] Example 16

[0208] Following the component metering of Example 5, PU5 particles were added to an electrolyte solvent of ethylene carbonate (EC), ethyl methyl carbonate (EMC), and dimethyl carbonate (DMC) in a 1 / 1 / 1 (v / v / v) ratio. The mixture was stirred at 50°C and maintained for 24 hours. Subsequently, LiPF6, a chemically crosslinkable monomer namely 1-vinyl-3-butylimidazolium trifluoromethanesulfonylimide salt, and azoisobutyronitrile (AIBN) were added at an amount equal to 1 wt.% of the chemically crosslinkable monomer and / or prepolymer mass. The mixture was stirred and homogenized at room temperature to obtain the polymer electrolyte precursor (E16).

[0209] The viscosity and particle size of the prepared polymer electrolyte precursor and the ionic conductivity of the polymer electrolyte obtained from the polymer electrolyte precursor were tested, and the results are shown in Table 3.

[0210] Comparative Examples 1-4

[0211] Compared with Example 5, PU1 was replaced with equal masses of polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), or polyethylene glycol (PEO), while other aspects remained the same as in Example 5, to prepare polymer electrolyte precursors (CE1-CE4).

[0212] The curing properties of the polymer electrolytes obtained from polymer electrolyte precursor E5 of Example 5 and polymer electrolyte precursors CE1-CE4 of Comparative Examples 1-4 were evaluated respectively. The ionic conductivity and linear sweep voltammetry of the polymer electrolytes obtained from the above polymer electrolyte precursors were measured respectively. The results are shown in Table 2 (where “—” indicates that the test conditions were not available or the test was meaningless).

[0213] Table 2

[0214]

[0215] As shown in Table 2, compared with polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), or polyethylene glycol (PEO), polyurethane-based polymer electrolytes have good curing properties, a significantly higher electrochemical stability range, and higher room temperature ionic conductivity.

[0216] Comparative Example 5

[0217] According to the component measurements in Table 3, PU6 particles were added to an electrolyte containing ethylene carbonate (EC), ethyl methyl carbonate (EMC), dimethyl carbonate (DMC) in a 1 / 1 / 1 (v / v / v) ratio, and 1M LiPF6, with LiPF6 accounting for 12.5 wt.% of the electrolyte. The mixture was stirred at 50°C for 24 hours. Subsequently, chemically crosslinkable monomers and / or prepolymers were added, including azoisobutyronitrile (AIBN) at a mass of 1 wt.% of the chemically crosslinkable monomers and / or prepolymers. The mixture was stirred and homogenized at room temperature to obtain the polymer electrolyte precursor (CE5).

[0218] The viscosity and particle size of the prepared polymer electrolyte precursor and the ionic conductivity of the polymer electrolyte obtained from the polymer electrolyte precursor were tested. The results are shown in Table 3 (where “—” indicates that the test conditions were not available or the test was meaningless).

[0219] Comparative Example 6

[0220] Following the component ratios of Example 1 (E1) in Table 3, PU1 was replaced with PU7 and added to an electrolyte comprising ethylene carbonate (EC), ethyl methyl carbonate (EMC), dimethyl carbonate (DMC) in a 1 / 1 / 1 (v / v / v) ratio, and 1M LiPF6, with LiPF6 comprising 12.5 wt.% of the electrolyte. The mixture was stirred at 50°C for 24 hours. It was found that PU7, due to its excessively high chemical cross-linking, could not dissolve in the electrolyte and therefore could not be used to prepare the polymer electrolyte precursor required for this invention.

[0221] Comparative Example 7

[0222] Compared with Example 1 (E1), the amount of PU1 was increased, and the rest was the same as in Example 1. See Table 3 for details to prepare the polymer electrolyte precursor (CE7).

[0223] The viscosity of the prepared polymer electrolyte precursor was tested, and the results are shown in Table 3. The state after standing at 25℃ for 12 hours is shown in Table 3. Figure 1 .Depend on Figure 1 It is known that the precursor solution is in a viscous state, has no fluidity, cannot be injected into the battery, and cannot penetrate well between the anode and cathode.

[0224] Solid-state battery fabrication and performance testing

[0225] The polymer electrolyte precursors (E1-E15) obtained in the examples were directly injected into dry cell batteries (lithium iron phosphate as the positive electrode and lithium metal as the negative electrode), with the injection amount controlled at a ratio of 4g of polymer electrolyte precursor solution per 1Ah of battery energy. The injected batteries were subjected to formation treatment at 45°C, then placed in a 60°C environment under pressure for 24 hours to complete in-situ polymerization. The batteries were then degassed and encapsulated to obtain solid-state batteries. Battery cycle tests were performed on the obtained solid-state batteries, and the results are shown in Table 3.

[0226]

[0227] As shown in Table 3, the polymer electrolyte precursor that meets the requirements of this invention has good injectability and can obtain polymer electrolytes with high ionic conductivity and low interfacial impedance. The solid-state lithium battery prepared by this invention has good cycle performance.

Claims

1. A polymer electrolyte precursor for preparing a solid-state battery or a semi-solid-state battery, the precursor comprising: A) a polyurethane; B) a chemically cross-linkable monomer and / or prepolymer; C) a lithium salt; D) an initiator; E) an electrolyte solvent; wherein the polyurethane is prepared from a polyol having an average functionality of 1.8 to 2.2, an isocyanate having an average functionality of 1.8 to 2.2, a chain extender, and an auxiliary agent, the polyurethane is dissolved or dispersed in the polymer electrolyte precursor at 25°C, the polymer electrolyte precursor has a viscosity of not more than 400 cP measured at 25°C, the B) chemically cross-linkable monomer and / or prepolymer comprises one or more compounds selected from the group consisting of: 1) a multifunctional acrylate-based monomer or a prepolymer thereof or a multifunctional methacrylate-based monomer or a prepolymer thereof; 2) a polyether or epoxy-modified acrylate compound or a polyether or epoxy-modified methacrylate compound; 3) an ionic liquid monomer having a polymerizable group; and further comprising or not comprising other monomers having an unsaturated double bond, the E) electrolyte solvent is selected from carbonate solvents.

2. The polymer electrolyte precursor according to claim 1, wherein: the polyurethane has a number average molecular weight of less than 100 000 g / mol.

3. The polymer electrolyte precursor according to claim 2, wherein: the polyurethane has a number average molecular weight of less than 60 000 g / mol.

4. The polymer electrolyte precursor according to claim 3, wherein: the polyurethane is a thermoplastic polyurethane having a number average molecular weight of 5 000 to 50 000 g / mol.

5. The polymer electrolyte precursor according to claim 1 or 2, wherein: the polyol is a polyether alcohol containing an ether oxygen bond.

6. The polymer electrolyte precursor according to claim 1 or 2, wherein: The polymerizable group of the ionic liquid monomer having a polymerizable group includes one or more of a vinyl group, an allyl group, an acrylate group, a methacrylate group, the ionic liquid monomer having a polymerizable group includes a cation selected from at least one of the following: an ammonium cation, a pyrrolidinium cation, a pyridinium cation, a pyrimidinium ion, an imidazolium cation, a piperidinium cation, a pyrazolium cation, an oxazolium cation, a pyridazinium cation, a phosphonium cation, a sulfonium cation, a triazolium cation, and at least one anion selected from the following: BF4 - , PF6 - , AsF6 - , SbF6 - , A1C14 - , HSO4 - , CIO4 - , CH3SO3 - , CF3CO2 - , (CF3SO2)2N - , (FSO2)2N - , CI - , Br - , I - , SO4 2- , CF3SO3 - , (C2F5SO2)2N - , NO3 - , A12C17 - , (CF3SO2)3C - , (CF3)3PF3 - , (CF3)4PF2 - , (CF3)5PF - , (CF3)6P - , SF5CF2SO3 - , (C2F5SO2)(CF3SO2) N - , SF5CHFCF2SO3 - , CF3CF2(CF3)2CO - , (CF3SO2)2CH - , (SF5)3C - , and (0(CF3)2C2(CF3)2O)2PO - .

7. The polymer electrolyte precursor according to claim 1 or 2, wherein: The chemically crosslinkable monomers and / or prepolymers in B) are selected from methoxylated polyethylene glycol methacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, polypropylene glycol diacrylate, polypropylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, dipropylene glycol diacrylate, dipropylene glycol diacrylate, dipropylene glycol diacrylate, bis(trimethylolpropane) acrylate, trimethylolpropane trimethacrylate, ethoxylated trimethylolpropane triacrylate, propoxy The monomers are selected from one or more of the following: methylolpropane triacrylate, pentaerythritol triacrylate, ethoxylated bisphenol A dimethacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, glycidyl acrylate, and glycidyl methacrylate; the other monomers having unsaturated double bonds are selected from one or more combinations of C1-C12 alkyl acrylates, C1-C12 alkyl methacrylates, methacrylamide, acrylamide, and ethylene carbonate.

8. The polymer electrolyte precursor according to claim 1 or 2, characterized in that, The sum of the contents of A) polyurethane and B) chemically crosslinkable monomers and / or prepolymers accounts for 1 wt.% to 35 wt.% of the total mass of the polymer electrolyte precursor.

9. The polymer electrolyte precursor according to claim 1 or 2, characterized in that, The sum of the contents of A) polyurethane and B) chemically crosslinkable monomers and / or prepolymers accounts for 3 wt.% to 30 wt.% of the total mass of the polymer electrolyte precursor.

10. The polymer electrolyte precursor according to claim 1 or 2, characterized in that, The sum of the contents of A) polyurethane and B) chemically crosslinkable monomers and / or prepolymers accounts for 7 wt.% to 25 wt.% of the total mass of the polymer electrolyte precursor.

11. The polymer electrolyte precursor according to claim 1 or 2, characterized in that, The mass of A) the polyurethane is less than 3 times the mass of B) the chemically crosslinkable monomers and / or prepolymers.

12. The polymer electrolyte precursor according to claim 1 or 2, characterized in that, The lithium salt in C) is selected from one or more combinations of lithium hexafluorophosphate, lithium bis(oxalato)borate, lithium difluorooxalato)borate, lithium tetrafluoroborate, lithium hexafluoroantimonyate, lithium hexafluoroarsenate, lithium perfluorobutyl sulfonate, lithium perchlorate, lithium aluminate, lithium tetrachloroaluminate, lithium trifluoromethanesulfonate, lithium bis(sulfonyl)imide, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonate)imide, lithium chloride, and lithium fluoride.

13. The polymer electrolyte precursor according to claim 1 or 2, characterized in that, The content of lithium salt in C) accounts for 5 wt.% to 30 wt.% of the total mass of the polymer electrolyte precursor.

14. The polymer electrolyte precursor of claim 13, wherein the content of the lithium salt is 7 wt.% to 20 wt.% of the total mass of the polymer electrolyte precursor.

15. The polymer electrolyte precursor of claim 1 or 2, wherein the content of the initiator is 0.2 wt.% to 2 wt.% of the mass of the chemically cross-linkable monomer and / or prepolymer.

16. The polymer electrolyte precursor of claim 1 or 2, wherein the polyurethane has a particle average size of less than 5 microns when dispersed in the polymer electrolyte precursor, as measured by laser diffraction at 25°C.

17. The polymer electrolyte precursor of claim 1 or 2, wherein the polyurethane has a particle average size of no more than 2 microns when dispersed in the polymer electrolyte precursor, as measured by laser diffraction at 25°C.

18. The polymer electrolyte precursor of claim 1 or 2, wherein the polymer electrolyte precursor further comprises an additive selected from one or more of inorganic nanoparticles, inorganic solid electrolyte particles, and ionic liquids, wherein the inorganic nanoparticles are selected from one or more of Al2O3, SiO2, ZnO, TiO2, ZrO2, Ga2O3, In2O3, GeO2, Nb2O5, SiC, MgS, and CaS; the inorganic solid electrolyte particles are selected from one or more of garnet-type lithium lanthanum zirconium oxide, perovskite-type lithium lanthanum titanium oxide, NASICON-type lithium aluminum titanium phosphorous oxide, and LISICON-type lithium aluminum germanium phosphorous oxide; and the ionic liquid is selected from one or more of imidazole-based ionic liquid, pyrrolidine-based ionic liquid, pyridine-based ionic liquid, quaternary ammonium salt-based ionic liquid, alkenyl-functionalized ionic liquid, and sulfonic acid-functionalized ionic liquid.

19. The polymer electrolyte precursor of claim 18, wherein the total content of the additive is 0.1 wt.% to 15 wt.% of the total mass of the polymer electrolyte precursor.

20. The polymer electrolyte precursor of claim 18, wherein the cation of the ionic liquid is one of 1-ethyl-3-methylimidazolium, 1-butyl-3-methylimidazolium, and N-butyl-N-methylpyrrolidinium, and the anion of the ionic liquid is one of bis(trifluoromethylsulfonyl)imide, hexafluorophosphate, and tetrafluoroborate.

21. A method for preparing the polymer electrolyte precursor of any one of claims 1 to 20, wherein the polyurethane is dissolved or dispersed in an electrolyte solvent, the chemically cross-linkable monomer and / or prepolymer, the initiator, and the lithium salt are added, and the mixture is stirred to obtain the polymer electrolyte precursor of any one of claims 1 to 20; or the polyurethane is dissolved or dispersed in an electrolyte of an electrolyte solvent and the lithium salt, the chemically cross-linkable monomer and / or prepolymer, and the initiator are added, and the mixture is stirred to obtain the polymer electrolyte precursor of any one of claims 1 to 20. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 22. The method of claim 21, wherein, the polyurethane is in the form of pellets or sheets.

23. The method of claim 21, wherein, the polyurethane is formed in situ in the electrolyte solvent or the electrolyte by mixing a component comprising a polyol having an average functionality of 1.8 to 2.2 and a component comprising an isocyanate having an average functionality of 1.8 to 2.

2.

24. A polymer electrolyte, characterized by, The polymer electrolyte precursor of any one of claims 1 to 20 or the polymer electrolyte precursor prepared according to the method of any one of claims 21 to 23 is injected into a battery and polymerized in situ.

25. The polymer electrolyte of claim 24, wherein, The polymer electrolyte comprises a semi-interpenetrating polymer network comprising a polyurethane and a chemical crosslinking product formed by polymerization of chemically crosslinkable monomers and / or prepolymers.

26. A method for preparing a solid-state battery or a semi-solid-state battery, wherein, the method comprises the following steps: Step i: injecting the polymer electrolyte precursor of any one of claims 1 to 20 or the polymer electrolyte precursor prepared according to the method of any one of claims 21 to 23 into a dry cell; Step ii: heating to polymerize in situ; Step iii: sealing; or, the method comprises pre-coating the polymer electrolyte precursor of any one of claims 1 to 20 or the polymer electrolyte precursor prepared according to the method of any one of claims 21 to 23 on the surface of an electrode and / or a separator, heating to polymerize in situ, allowing it to solidify on the surface of the electrode and / or the separator, and then obtaining a solid-state battery or a semi-solid-state battery by lamination or winding.

27. The method for preparing a solid-state battery or a semi-solid-state battery according to claim 26, wherein, the temperature of the in situ polymerization is 25°C to 100°C, and the time of the in situ polymerization is 10 minutes to 24 hours.

28. The method for preparing a solid-state battery or a semi-solid-state battery according to claim 26 or 27, wherein, the method further comprises a formation step, and the formation temperature is 25°C to 120°C.

29. The method for preparing a solid-state battery or a semi-solid-state battery according to claim 28, wherein, the formation temperature is 25°C to 50°C.

30. A solid-state battery or semi-solid-state battery, characterized by, which comprises the polymer electrolyte of claim 24 or 25, or which is prepared by the method for preparing a solid-state battery or a semi-solid-state battery according to any one of claims 26 to 29.

31. Use of a solid-state or semi-solid-state battery according to claim 30 in an electrical device, characterized in that, The electrical device contains the solid-state battery or the semi-solid-state battery of claim 30.

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