A photocurable polysiloxane, a method for preparing the same, and use thereof as a polymer solid electrolyte

Abstract

The application provides a preparation method of a photocurable high dielectric constant polysiloxane and a solid electrolyte membrane application containing the elastomer. The high dielectric constant polysiloxane of the application is a polysiloxane containing a special polar group in a side chain and an acrylate group or an epoxy group capable of being photocured in a chain end. The high dielectric constant polysiloxane is prepared through ring-opening polymerization of a ring containing a special polar side chain, is coated on the surface of a pole piece after being blended with a lithium salt, is cured in situ under ultraviolet light, and then an electrolyte membrane is obtained. The preparation process of the polymer in the application is simple, the ionic conductivity of the solid polymer electrolyte membrane can be effectively controlled according to needs, the in-situ curing method increases the interfacial compatibility of the solid polymer electrolyte membrane and the pole piece, can further reduce the interfacial impedance between the two, and promotes the practical application of the polysiloxane-based solid polymer electrolyte membrane.

Description

Technical Field

[0001] This invention belongs to the field of polymer preparation and solid polymer electrolyte technology for lithium-ion batteries, and relates to a method for preparing a photocurable high-dielectric-constant polysiloxane, and the application of a solid electrolyte membrane containing this elastomer. Specifically, it involves preparing a polysiloxane solid electrolyte membrane with high ion transport performance by mixing a high-dielectric-constant polysiloxane with a lithium salt and then photocuring it, and then applying it to lithium-ion batteries. Background Technology

[0002] Lithium-ion batteries possess advantages such as high energy density, long cycle life, high output power, and no memory effect, making them widely used in portable electronic products and electric vehicles. A lithium-ion battery consists of a positive electrode, a negative electrode, a separator, and an electrolyte. The electrolyte is typically a flammable organic solvent, mainly including low-boiling-point carbonates, ethers, and hydroxy acid esters, posing a significant risk of flammability and explosion. Novel solid-state electrolytes can replace the separator and electrolyte components in traditional lithium-ion batteries, potentially solving the problem of battery safety and further expanding the battery's operating temperature range. This has become one of the most promising research directions in recent years. Solid-state electrolytes are divided into inorganic solid-state electrolytes and solid polymer electrolytes. Inorganic solid-state electrolytes have lithium-ion transference numbers close to 1, and room-temperature ionic conductivity can reach 10-1. -2 While high-energy-density polymers (S / cm) have a high energy density, their preparation process is complex, and they suffer from severe interfacial problems. Many issues still need to be addressed before they can be applied. In contrast, solid-state polymer electrolytes (SPEs) offer advantages such as high energy density, good safety, high interfacial compatibility, and good flexibility. They also have a wider operating range and are easier to mass-produce, gradually becoming a trend and research hotspot in the development of next-generation electrolytes.

[0003] Lithium-ion transport in solid polymer electrolyte membranes follows an amorphous region conduction mechanism. Under the influence of an electric field, lithium ions form coordination structures with polar groups, undergoing complexation-decomplexation processes due to the thermal motion of polymer chains, thus completing their directional migration. Therefore, the polymer matrix must contain polar groups capable of generating ion-dipole interactions with lithium ions. Based on the type of polymer groups, solid polymer electrolyte membranes are mainly classified into polyethers, polycarbonates, polyacrylonitrile, and polyvinylidene fluoride (PVDF) matrices. However, the glass transition temperatures of these polar polymer matrices are generally above room temperature, and they may even exhibit significant crystallization, limiting their low-temperature chain mobility and restricting their use to high-temperature environments. Therefore, there is an urgent need to develop a polymer system that retains good chain mobility at room temperature to improve the room-temperature ionic conductivity of solid polymer electrolyte membranes. Polysiloxanes, as organic-inorganic hybrid polymers, have a low glass transition temperature (Tg≈-123℃) and excellent chain mobility, making them a promising candidate for use as a matrix for low-temperature electrolyte membranes. However, the intrinsic ionic conductivity of commonly used methyl-substituted polysiloxane systems is only 10. -10 S cm -1 To enable polysiloxanes to be used as a matrix for solid polymer electrolyte membranes and to move from the laboratory to commercial applications, issues such as their ionic conductivity, stability, and interfacial compatibility with electrodes require further research and improvement. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a method for preparing a photocurable high-dielectric-constant polysiloxane, and the application of a solid electrolyte membrane containing this elastomer. The high-dielectric-constant polysiloxane of this invention is a polysiloxane with special polar groups on its side chains and photocurable acrylate or epoxy groups at the chain ends. The high-dielectric-constant polysiloxane is prepared through ring-opening polymerization of the ring containing the special polar side chains. After being blended with lithium salts and coated onto the surface of an electrode, it is cured in situ under ultraviolet light to obtain an electrolyte membrane. The polymer preparation process in this invention is simple, and the ionic conductivity of the solid polymer electrolyte membrane can be effectively controlled as needed. Simultaneously, the in-situ curing method increases the interfacial compatibility between the solid polymer electrolyte membrane and the electrode, further reducing the interfacial impedance and promoting the practical application of polysiloxane-based solid polymer electrolyte membranes.

[0005] This invention is achieved through the following technical solution:

[0006] A photocurable high dielectric constant polysiloxane comprising at least one polymer having the structure shown in Formula I;

[0007]

[0008] Among them, R1, R2, and R3 may be the same or different, and are independently selected from C. 1-6 Alkyl, C 6-12 aryl-substituted C 1-6 Alkyl, C 6-12 aryl, at least one C 1-6 Alkyl-substituted C 6-12 Aryl;

[0009] R4 is selected from CN, CHO, nitro, amino, COOH, halogen, or C. 1-6 Alkyl, provided that the C 1-6 The alkyl group is substituted by one, two or more of the following groups: CN, CHO, nitro, amino, COOH or halogen;

[0010] Each R5 is either the same or different, and is selected independently from C. 1-6 Alkyl, C 6-12 aryl-substituted C 1-6 Alkyl, C 6-12 aryl, at least one C 1-6 Alkyl-substituted C 6-12 Aryl, -C 1-6 Alkyl-acrylate group, -C 1-6 Alkyl-methacrylate or -OC 1-6 Alkyl-C 2-4 Epoxyalkyl; provided that at least one of the R5 groups at each end of the polymer in Formula I is selected from one of the following groups: -C 1-6 Alkyl-acrylate group, -C 1-6 Alkyl-methacrylate or -OC 1-6 Alkyl-C 2-4 Epoxyalkyl;

[0011] m+n is any integer greater than 0 and less than or equal to 1000, and m is not 0.

[0012] According to embodiments of the present invention, R1, R2 and R3 may be the same or different, and each is independently selected from methyl, ethyl, ethylphenyl, 2,4-dimethylphenyl or benzyl.

[0013] According to embodiments of the present invention, R4 is selected from nitro, amino, -CH2X, -CH(X)CH3, -CH2CH2X, -CY3, -CH(Y)CH(Y)2, -C(Y)2CH2Y, wherein X is selected from -CN, amino, -C(=O)H, -COOH or halogen, and Y is selected from halogen; specifically, the halogen is selected from F, Cl, Br or I, and even more specifically, is selected from F or Cl; exemplaryly, X is selected from -CN, amino or Cl, and Y is selected from F.

[0014] According to embodiments of the present invention, each R5 may be the same or different, and is independently selected from methyl, ethyl, -(CH2)3OC(=O)C(CH3)=CH2, -(CH2)3OC(=O)CH=CH2 or -OCH2(CHCH2O), provided that at least one group in each of the R5s at both ends of the polymer in Formula I is -(CH2)3OC(=O)C(CH3)=CH2, -(CH2)3OC(=O)CH=CH2 or -OCH2(CHCH2O).

[0015] According to an embodiment of the present invention, m is any integer from 1 to 1000, and n is any integer from 0 to 999. Preferably, m is any integer from 100 to 500, and n is any integer from 0 to 499.

[0016] In a specific embodiment of the present invention, the polymer having the structure shown in Formula I may have any one of the structures shown in Formulas I-A, I-B, I-C, I-D, I-E, and I-F:

[0017]

[0018]

[0019] In equations I-A, I-B, I-C, I-D, I-E and IF, m and n all have the meanings described above.

[0020] In specific embodiments of the present invention, in Formula I-A, m can specifically be 100 and n can specifically be 400; in Formula I-A, m can specifically be 200 and n can specifically be 300; in Formula I-A, m can specifically be 300 and n can specifically be 200; in Formula I-A, m can specifically be 400 and n can specifically be 100; in Formula I-A, m can specifically be 450 and n can specifically be 50; in Formula I-A, m can specifically be 500 and n can specifically be 0; m can specifically be 103 and n can specifically be 309; m can specifically be 198 and n can specifically be 198; m can specifically be 297 and n can specifically be 99; m can specifically be 404 and n can specifically be 0.

[0021] In specific embodiments of the present invention, in Formula I-B, m can specifically be 100 and n can specifically be 400; in Formula I-B, m can specifically be 200 and n can specifically be 300; in Formula I-B, m can specifically be 300 and n can specifically be 200; in Formula I-B, m can specifically be 400 and n can specifically be 100; in Formula I-B, m can specifically be 450 and n can specifically be 50; in Formula I-B, m can specifically be 500 and n can specifically be 0; m can specifically be 404 and n can specifically be 0.

[0022] In specific embodiments of the present invention, in Formula I-C, m can specifically be 100 and n can specifically be 400; in Formula I-C, m can specifically be 200 and n can specifically be 300; in Formula I-C, m can specifically be 300 and n can specifically be 200; in Formula I-C, m can specifically be 400 and n can specifically be 100; in Formula I-C, m can specifically be 450 and n can specifically be 50; in Formula I-C, m can specifically be 500 and n can specifically be 0.

[0023] In specific embodiments of the present invention, in formula I-D, m can specifically be 100 and n can specifically be 400; in formula I-D, m can specifically be 200 and n can specifically be 300; in formula I-D, m can specifically be 300 and n can specifically be 200; in formula I-D, m can specifically be 400 and n can specifically be 100; in formula I-D, m can specifically be 450 and n can specifically be 50; in formula I-D, m can specifically be 500 and n can specifically be 0.

[0024] In specific embodiments of the present invention, in formulas I-E and IF, m can specifically be 100 and n can specifically be 400; in formula I-E, m can specifically be 200 and n can specifically be 300; in formula I-E, m can specifically be 300 and n can specifically be 200; in formula I-E, m can specifically be 400 and n can specifically be 100; in formula I-E, m can specifically be 450 and n can specifically be 50; in formula I-E, m can specifically be 500 and n can specifically be 0; in formula I-F, m can specifically be 404 and n can specifically be 0.

[0025] According to an embodiment of the present invention, the dielectric constant of the polysiloxane is 2-20 (10⁻⁶). 5 (Hz), preferably with a dielectric constant of 8.5-18.5 (10 Hz). 5 Hz).

[0026] The present invention further provides a method for preparing the above-mentioned photocurable high dielectric constant polysiloxane, comprising the following steps: using a cyclosiloxane monomer having the structure shown in Formula II and a compound having the structure shown in Formula III as end-capping agents to carry out a ring-opening polymerization reaction under the action of a catalyst to obtain the polysiloxane shown in Formula I.

[0027]

[0028] In Equation II, a+b is any integer greater than 2 and less than or equal to 6, and a is not 0; R1, R2, R3, and R4 have the meanings described above.

[0029]

[0030] In Equation III, R5 has the meanings described above.

[0031] According to an embodiment of the present invention, the molar ratio of the polymer having the structure shown in Formula II to the compound having the structure shown in Formula III can be 250:(15 to 1), specifically 250:(10 to 2), for example 250:10, 250:9, 250:8, 250:7, 250:6, 250:5, 250:4, 250:3, 250:2 or 250:1.

[0032] According to an embodiment of the present invention, the ring-opening polymer reaction is carried out in an organic solvent.

[0033] According to an embodiment of the present invention, the organic solvent may be one or more of N-methylpyrrolidone, N,N-dimethylformamide, 1,4-dioxane, ethyl acetate, chloroform, tetrahydrofuran, toluene, methanol, ethanol, isopropanol, butanol, hexane, benzene, acetone, butanone, cyclohexanone, o-xylene, p-xylene, and m-xylene.

[0034] According to an embodiment of the present invention, the mass of the organic solvent may be 0.5 to 10 times the total mass of the polymer having the structure shown in Formula II and the compound having the structure shown in Formula III, specifically 1 to 5 times, for example 1, 2, 3, 4, 5 or 6 times.

[0035] According to an embodiment of the present invention, the catalyst may be an anionic catalyst or a cationic catalyst.

[0036] According to an embodiment of the present invention, the anionic catalyst may be one or more of KOH, NaOH, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylphosphine hydroxide, benzyltrimethylammonium bis(catechol)phenylsilane, n-butyllithium, potassium tert-butoxide, lithium hydroxide, diethylamine, lithium silanolate, and potassium silanolate.

[0037] According to an embodiment of the present invention, the cationic catalyst may be one or more of concentrated H2SO4, HClO4, Lewis acid, trifluoromethanesulfonic acid, and di(trifluoromethanesulfonyl)imide.

[0038] According to an embodiment of the present invention, the mass of the catalyst may be 0.05% to 20% of the total mass of the polymer having the structure shown in Formula II and the compound having the structure shown in Formula III, specifically 0.1% to 10%, for example 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7% or 8%.

[0039] According to an embodiment of the present invention, the temperature of the ring-opening polymerization reaction can be 25°C to 130°C, specifically 35°C to 120°C, for example 35°C, 50°C, 70°C, 80°C, 95°C or 110°C.

[0040] According to an embodiment of the present invention, the ring-opening polymerization reaction can take 0.1h to 48h, specifically 0.3h to 24h, for example 0.5h, 2h, 4h, 6h, 8h, 12h or 24h.

[0041] According to an embodiment of the present invention, the preparation method specifically includes the following steps:

[0042] Step 1: Under continuous mechanical stirring, the compounds having the structures shown in Formula II and Formula III are mixed evenly in an organic solvent;

[0043] Step 2: Under an inert atmosphere (such as N2), add an appropriate amount of catalyst, heat to the required reaction temperature, and continuously stir the reaction. Use silicon spectroscopy to confirm whether the reaction has reached equilibrium. After the reaction is complete, the photocurable high dielectric constant polysiloxane can be obtained.

[0044] In some embodiments of the present invention, the polymer having the structure shown in Formula II may specifically be a cyclosiloxane monomer having the structures shown in Formula II-A, Formula II-B, and Formula II-C below, containing polar side chain substitutions:

[0045]

[0046] In Equations II-A and II-B, a+b can specifically be 4, and a is not equal to 0. For example, a is 1 and b is 3; a is 2 and b is 2; a is 3 and b is 1; or a is 4 and b is 0.

[0047] In Equation II-C, a+b can specifically be 3, and a is not equal to 0. For example, a is 1 and b is 2; a is 2 and b is 1; a is 3 and b is 0.

[0048] In some embodiments of the present invention, the compound having the structure shown in Formula III may specifically be a compound having the structure shown in Formula III-A below:

[0049]

[0050] The present invention also provides the application of the above-mentioned photocurable high dielectric constant polysiloxane in the preparation of solid polymer electrolyte membrane materials for lithium-ion batteries.

[0051] The solid polymer electrolyte material for lithium-ion batteries described in this invention includes: a photocurable high dielectric constant polysiloxane, a lithium salt, and a photoinitiator, as described above.

[0052] According to an embodiment of the present invention, the solid polymer electrolyte material for lithium-ion batteries is prepared by the following method:

[0053] Step 1: Add the above-mentioned polysiloxane and lithium salt to the light-proof reaction bottle, and let them be fully dissolved and mixed in the organic solvent to obtain a uniform colorless and transparent solution;

[0054] Step 2: Add photoinitiator to the above mixed solution, stir evenly, pour the solution into a polytetrafluoroethylene mold, dry in a vacuum oven at 30-60℃ for 24-48h, and then place it in a glove box to cure with ultraviolet light to obtain a solid polymer electrolyte membrane material with a film thickness of 200-400μm.

[0055] According to the present invention, the lithium salt mentioned in step 1 may be LiNO3, LiClO4, LiBF4, LiAsF6, LiPF6, LiBOB, LiDFOB, LiFSI, LiTFSI, LiSbF6, LiN(C4F9SO2)2, LiCF3CO2, LiAlCl4, or Li2B. 12 F 12 One or more of LiCF3SO3.

[0056] According to the present invention, the mass percentage of lithium salt in step 1 can be 10% to 400% of polysiloxane, for example, 30% to 200%, such as 10%, 30%, 50%, 70%, 100%, 130%, 150% or 200%.

[0057] According to the present invention, the organic solvent in step 1 may be one or more of N-methylpyrrolidone, N,N-dimethylformamide, 1,4-dioxane, ethyl acetate, chloroform, tetrahydrofuran, toluene, methanol, ethanol, isopropanol, butanol, hexane, benzene, acetone, butanone, cyclohexanone, o-xylene, p-xylene, and m-xylene.

[0058] According to the present invention, the mass of the organic solvent in step 1 can be 2 to 10 times the total mass of the polysiloxane and the lithium salt, specifically 2 to 6 times, for example 2 times, 3 times, 4 times, 5 times or 6 times.

[0059] According to the present invention, the photoinitiator in step 2 may be one or more of the following: 2,4,6-(trimethylbenzoyl)diphenylphosphine oxide (TPO photoinitiator), ethyl 2,4,6-trimethylbenzoylphosphonate (TPO-L photoinitiator), 2-methyl-1-[4-methylthiophenyl]-2-morpholinyl-1-propanone (907 photoinitiator), 2-isopropylthioxanthone (2,4 isomer mixture) (ITX photoinitiator), ethyl 4-dimethylaminobenzoate (EDB photoinitiator), 1-hydroxy-cyclohexylphenyl ketone (184 photoinitiator), 2-hydroxy-2-methyl-1-phenyl-1-propanone (1173 photoinitiator), 2,2-dimethoxy-2-phenylethyl ketone (BDK photoinitiator), or methyl o-benzoylbenzoate (0MBB photoinitiator).

[0060] According to the present invention, the mass percentage of the photoinitiator in step 2 can be 0.05% to 10% of the polysiloxane, specifically 0.5% to 5%, for example 0.5%, 1%, 2%, 3%, 4% or 5%.

[0061] According to the present invention, the ultraviolet light irradiation time in step 2 can be 0.1h to 6h, specifically 0.2h to 2h, for example 0.2h, 0.4h, 0.6h, 0.8h, 1h, 1.5h or 2h.

[0062] According to the present invention, the wavelength of the ultraviolet lamp in step 2 can be 200-400nm, specifically 220-400nm, such as 231nm, 244nm, 253nm, 258nm, 273nm, 299nm, 307nm, 365nm or 370nm.

[0063] According to the present invention, the thickness of the solid polymer electrolyte membrane material is 200 nm to 400 nm, preferably 250 nm.

[0064] According to the present invention, the room temperature ionic conductivity of the solid polymer electrolyte membrane material is 1×10⁻⁶. -6 ~8×10 -5 S cm -1 .

[0065] According to the present invention, the high-temperature (80°C) ionic conductivity of the solid polymer electrolyte membrane material is 1×10⁻⁶. -4 ~8×10 -3 Scm -1 .

[0066] According to the present invention, the room temperature electrochemical stability window of the solid polymer electrolyte membrane material is 1 × 5.2 to 5.6 V (vs Li / Li). + ).

[0067] The beneficial effects of this invention are:

[0068] Compared with the prior art, the photocurable high dielectric constant polysiloxane of the present invention has high thermal stability and a glass transition temperature much lower than room temperature. Compared with the thermocuring method of organosilicon elastomers, it greatly shortens the curing time, has a simple preparation process, and has good compatibility with lithium salts.

[0069] The solid polymer electrolyte membrane material prepared using the above-mentioned high dielectric constant polysiloxane has good flexibility, high ionic conductivity, wide electrochemical stability window, and high heat resistance, and can be adapted for use with high voltage cathode materials. Based on the use of polysiloxane, the solid polymer electrolyte membrane material of the present invention is green and environmentally friendly, has good thermal stability, is non-flammable and leak-proof, and greatly improves the safety performance of lithium-ion batteries.

[0070] Terminology Definitions and Explanations

[0071] In this document, the terms “comprising,” “including,” and / or “containing” are open-ended expressions, meaning they include the contents specified in this invention but do not exclude other aspects.

[0072] In this document, the term "any integer between 1 and 1000" refers to every integer from 1 to 1000. Due to space limitations, not all are listed here, but those skilled in the art will recognize that it includes every integer from 1 to 1000. Furthermore, the same definition also includes "any integer between 0 and 999," "any integer between 100 and 500," and so on.

[0073] In this document, the term "halogen" refers to fluorine, chlorine, bromine, and / or iodine. Accordingly, the term "halogenated" refers to fluorination, chlorination, bromination, and / or iodination. Within the scope of this document, when an atom, residue, group, or part is halogenated, the atom at the halogenated position can be monosubstituted, disubstituted, or polysubstituted up to fully substituted by the halogen atom.

[0074] Term "C" 1-6 "Alkyl" should be understood to mean a straight-chain or branched saturated monovalent hydrocarbon group having 1, 2, 3, 4, 5, or 6 carbon atoms. The alkyl group is, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, 2-methylbutyl, 1-methylbutyl, 1-ethylpropyl, 1,2-dimethylpropyl, neopentyl, 1,1-dimethylpropyl, 4-methylpentyl, 3-methylpentyl, 2-methylpentyl, 1-methylpentyl, 2-ethylbutyl, 1-ethylbutyl, 3,3-dimethylbutyl, 2,2-dimethylbutyl, 1,1-dimethylbutyl, 2,3-dimethylbutyl, 1,3-dimethylbutyl, or 1,2-dimethylbutyl, or their isomers. In particular, the group has 1, 2, or 3 carbon atoms ("C"). 1-3 Alkyl), such as methyl, ethyl, n-propyl or isopropyl.

[0075] Term "C" 2-4 "Epoxyalkyl" refers to a saturated monovalent monocyclic hydrocarbon ring containing one or two oxygen atoms and 2-4 carbon atoms. The C... 2-4 Epoxyalkyl groups include, but are not limited to, ethylene oxide, propylene oxide, or butyl oxide.

[0076] Term "C" 6-12 "Aryl" should be understood as representing a monovalent aromatic or partially aromatic monocyclic, bicyclic, or tricyclic hydrocarbon ring ("C") having 6, 7, 8, 9, 10, 11, or 12 carbon atoms. 6-12Aryl), particularly a ring with 6 carbon atoms (“C6 aryl”), such as phenyl; or biphenyl, or a ring with 9 carbon atoms (“C9 aryl”), such as indenyl or indenyl, or a ring with 10 carbon atoms (“C9 aryl”). 10 Aryl), such as tetrahydronaphthyl, dihydronaphthyl or naphthyl.

[0077] The above refers to the term "C" 1-6 The definition of "alkyl" also applies to compounds containing "C". 1-6 Other terms for "alkyl", such as the term "halogenated C", 1-6 alkyl". Attached Figure Description

[0078] Figure 1 The images show the 1H NMR spectra of the photocurable high dielectric constant polysiloxanes of Examples 1-4 and the photocurable polysiloxane control sample in Comparative Example 1.

[0079] Figure 2 This is a gel permeation chromatogram of the photocurable high dielectric constant polysiloxane of Example 4. Figure 3 The infrared spectra are of the photocurable high dielectric constant polysiloxanes of Examples 1-4 and the photocurable polysiloxane control sample in Comparative Example 1.

[0080] Figure 4 The DSC spectra are of the photocurable high dielectric constant polysiloxanes of Examples 1-4 and the photocurable polysiloxane control sample in Comparative Example 1.

[0081] Figure 5 The surface morphology of the solid polymer electrolyte membrane material in Example 8 is shown.

[0082] Figure 6 The image shows the cross-sectional morphology of the solid polymer electrolyte membrane material in Example 8.

[0083] Figure 7 The image shows the AC impedance spectra of the solid polymer electrolyte membrane material of Example 4 at different temperatures.

[0084] Figure 8 The electrochemical stability window of the solid polymer electrolyte membrane material in Example 4 was obtained by testing at room temperature.

[0085] Figure 9 This is a curved image of the solid polymer electrolyte membrane material of Example 8.

[0086] Figure 10 The thermogravimetric curve is shown for the solid polymer electrolyte membrane material of Example 8. Detailed Implementation

[0087] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0088] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0089] The following examples illustrate the method for testing and calculating ionic conductivity (σ): A solid electrolyte membrane material is sandwiched between two stainless steel electrodes (SS) to assemble an SS / SPE / SS blocking electrode for ionic conductivity testing. The AC impedance spectrum of the blocking battery is obtained on an electrochemical workstation, and the bulk impedance Rs of the electrolyte is recorded. The test frequency range is 10 Hz. 6 -10 -1 The Hz frequency and the disturbance voltage are 10mV. The ionic conductivity (σ) of the electrolyte is calculated using the following formula:

[0090]

[0091] Where l (cm) is the thickness of the electrolyte membrane; Rs (Ω) is the bulk impedance of the electrolyte membrane; S (cm) 2 The contact area between the electrolyte membrane and the stainless steel electrode is denoted as (SPE / SS). This contact area is sandwiched between the stainless steel electrode (SS) and the lithium metal electrode (Li) to assemble a Li / SPE / SS test cell. The electrochemical stability of the electrolyte is tested using linear sweep voltammetry (LSV). The potential range for LSV testing is 0-6.5V, and the scan rate is 1 mV / s. -1 .

[0092] The electrochemical properties of the materials in the following examples and comparative examples were all tested at a certain temperature using an Autolab 302N electrochemical workstation manufactured by Metrohm, Switzerland, and a CHI1600E electrochemical workstation manufactured by Shanghai Chenhua Instrument Co., Ltd.

[0093] Example 1: Preparation of photocurable high dielectric constant polysiloxane and solid polymer electrolyte membrane materials

[0094] Preparation of photocurable high dielectric constant polysiloxane: Under N2 protection, 50 g of methyl cyanopropylcyclosiloxane (Formula II-A) and 0.5 g of (1,1,3,3-tetramethyldisiloxane-1,3-diyl)dipropane-1,3-diyl diacrylate (Formula III-A) were added to a 500 ml three-necked flask, along with 100 g of N,N-dimethylformamide. The mixture was stirred for 10 minutes until homogeneous. The temperature was raised to 70 °C, and 1 g of concentrated H2SO4 was added to the flask using a pipette. After reacting for 48 h, the solvent and catalyst were removed to obtain the polymer shown in I-A (where m is 103 and n is 309), which is a photocurable high dielectric constant polysiloxane, named PCDMS-1.

[0095] In the structure shown in Equation II-A, a is 1 and b is 3.

[0096] Preparation of solid polymer electrolyte membrane material: In a glove box (H2O < 0.1 ppm, O2 < 0.1 ppm), 1.0 g PCDMS-1, 0.45 g LiTFSI, and 0.02 g BDK photoinitiator were fully dissolved in 4 g N,N-dimethylformamide to form a uniform, transparent, colorless solution. This solution was cast onto a tetrafluoroethylene mold, and after evaporating the organic solvent in a vacuum oven, it was irradiated with 360 nm ultraviolet light in a glove box for 2 hours until completely cured, thus obtaining the solid polymer electrolyte membrane material, named SPE-1.

[0097] The dielectric constant of the photocurable high dielectric constant polysiloxane prepared in this embodiment is shown in Table 1.

[0098] The electrochemical properties of the solid polymer electrolyte membrane material prepared in this embodiment are shown in Tables 2 and 3.

[0099] Example 2: Preparation of photocurable high dielectric constant polysiloxane and solid polymer electrolyte membrane materials

[0100] Preparation of photocurable high dielectric constant polysiloxane: Under N2 protection, 50 g of methyl cyanopropylcyclosiloxane (Formula II-A) and 0.45 g of (1,1,3,3-tetramethyldisiloxane-1,3-diyl)dipropane-1,3-diyl diacrylate (Formula III-A) were added to a 500 ml three-necked flask, along with 100 g of N,N-dimethylformamide. The mixture was stirred for 10 minutes until homogeneous. The temperature was raised to 70 °C, and 1 g of concentrated H2SO4 was added to the flask using a pipette. After reacting for 48 h, the solvent and catalyst were removed to obtain the polymer shown in I-A (where m is 198 and n is 198), which is the photocurable high dielectric constant polysiloxane, named PCDMS-2.

[0101] In the structure shown in Equation II-A, a is 2 and b is 2.

[0102] Preparation of solid polymer electrolyte membrane material: In a glove box (H2O < 0.1 ppm, O2 < 0.1 ppm), 1.0 g PCDMS-2, 0.45 g LiTFSI, and 0.02 g BDK photoinitiator were fully dissolved in 4 g N,N-dimethylformamide to form a uniform, transparent, colorless solution. This solution was cast onto a tetrafluoroethylene mold, and after evaporating the organic solvent in a vacuum oven, it was irradiated with 360 nm ultraviolet light in a glove box for 2 hours until completely cured, thus obtaining the solid polymer electrolyte membrane material, named SPE-2.

[0103] The dielectric constant of the photocurable high dielectric constant polysiloxane prepared in this embodiment is shown in Table 1.

[0104] The electrochemical properties of the solid polymer electrolyte membrane material prepared in this embodiment are shown in Tables 2 and 3.

[0105] Example 3: Preparation of photocurable high dielectric constant polysiloxane and solid polymer electrolyte membrane materials

[0106] Preparation of photocurable high dielectric constant polysiloxane: Under N2 protection, 50 g of methyl cyanopropylcyclosiloxane (Formula II-A) and 0.4 g of (1,1,3,3-tetramethyldisiloxane-1,3-diyl)dipropane-1,3-diyl diacrylate (Formula III-A) were added to a 500 ml three-necked flask, along with 100 g of N,N-dimethylformamide. The mixture was stirred for 10 minutes until homogeneous. The temperature was raised to 70 °C, and 1 g of concentrated H2SO4 was added to the flask using a pipette. After reacting for 48 h, the solvent and catalyst were removed to obtain the polymer shown in I-A (where m is 297 and n is 99), which is the photocurable high dielectric constant polysiloxane, named PCDMS-3.

[0107] In the structure shown in Equation II-A, a is 3 and b is 1.

[0108] Preparation of solid polymer electrolyte membrane material: In a glove box (H2O < 0.1 ppm, O2 < 0.1 ppm), 1.0 g PCDMS-3, 0.45 g LiTFSI, and 0.02 g BDK photoinitiator were fully dissolved in 4 g N,N-dimethylformamide to form a uniform, transparent, colorless solution. This solution was cast onto a tetrafluoroethylene mold, and after evaporating the organic solvent in a vacuum oven, it was irradiated with 360 nm ultraviolet light in a glove box for 2 hours until completely cured, thus obtaining the solid polymer electrolyte membrane material, named SPE-3.

[0109] The dielectric constant of the photocurable high dielectric constant polysiloxane prepared in this embodiment is shown in Table 1.

[0110] The electrochemical properties of the solid polymer electrolyte membrane material prepared in this embodiment are shown in Tables 2 and 3.

[0111] Example 4: Preparation of photocurable high dielectric constant polysiloxane and solid polymer electrolyte membrane materials

[0112] Preparation of photocurable high dielectric constant polysiloxane: Under N2 protection, 50 g of methyl cyanopropylcyclosiloxane (Formula II-A) and 0.35 g of (1,1,3,3-tetramethyldisiloxane-1,3-diyl)dipropane-1,3-diyl diacrylate (Formula III-A) were added to a 500 ml three-necked flask, along with 100 g of N,N-dimethylformamide. The mixture was stirred for 10 minutes until homogeneous. The temperature was raised to 70 °C, and 1 g of concentrated H2SO4 was added to the flask using a pipette. After reacting for 48 h, the solvent and catalyst were removed to obtain the polymer shown in I-A (where m is 404 and n is 0), which is the photocurable high dielectric constant polysiloxane, named PCMS-4.

[0113] In the polymer shown in Formula II-A, a is 4 and b is 0.

[0114] Preparation of solid polymer electrolyte membrane material: In a glove box (H2O < 0.1 ppm, O2 < 0.1 ppm), 1.0 g PCMS-4, 0.45 g LiTFSI, and 0.02 g BDK photoinitiator were fully dissolved in 4 g N,N-dimethylformamide to form a uniform, transparent, colorless solution. This solution was cast onto a tetrafluoroethylene mold, and after evaporating the organic solvent in a vacuum oven, it was irradiated with 360 nm ultraviolet light in a glove box for 2 hours until completely cured, thus obtaining the solid polymer electrolyte membrane material, named SPE-4.

[0115] The dielectric constant of the photocurable high dielectric constant polysiloxane prepared in this embodiment is shown in Table 1.

[0116] The electrochemical properties of the solid polymer electrolyte membrane material prepared in this embodiment are shown in Tables 2 and 3.

[0117] Example 5: Preparation of photocurable high dielectric constant polysiloxane and solid polymer electrolyte membrane materials

[0118] Preparation of photocurable high dielectric constant polysiloxane: The preparation process is the same as in Example 4.

[0119] Preparation of solid polymer electrolyte membrane material: In a glove box (H2O < 0.1 ppm, O2 < 0.1 ppm), 1.0 g PCMS-4, 0.75 g LiTFSI, and 0.02 g BDK photoinitiator were fully dissolved in 4 g N,N-dimethylformamide to form a uniform, transparent, colorless solution. This solution was cast onto a tetrafluoroethylene mold, and after evaporating the organic solvent in a vacuum oven, it was irradiated with 360 nm ultraviolet light in a glove box for 2 hours until completely cured, thus obtaining the solid polymer electrolyte membrane material, named SPE-5.

[0120] The electrochemical properties of the solid polymer electrolyte membrane material prepared in this embodiment are shown in Tables 2 and 3.

[0121] Example 6: Preparation of photocurable high dielectric constant polysiloxane and solid polymer electrolyte membrane materials

[0122] Preparation of photocurable high dielectric constant polysiloxane: The preparation process is the same as in Example 4.

[0123] Preparation of solid polymer electrolyte membrane material: In a glove box (H2O < 0.1 ppm, O2 < 0.1 ppm), 1.0 g PCMS-4, 1.00 g LiTFSI, and 0.02 g BDK photoinitiator were fully dissolved in 4 g N,N-dimethylformamide to form a uniform, transparent, colorless solution. This solution was cast onto a tetrafluoroethylene mold, and after evaporating the organic solvent in a vacuum oven, it was irradiated with 360 nm ultraviolet light in a glove box for 2 hours until completely cured, thus obtaining the solid polymer electrolyte membrane material, named SPE-6.

[0124] The electrochemical properties of the solid polymer electrolyte membrane material prepared in this embodiment are shown in Tables 2 and 3.

[0125] Example 7: Preparation of photocurable high dielectric constant polysiloxane and solid polymer electrolyte membrane materials

[0126] Preparation of photocurable high dielectric constant polysiloxane: The preparation process is the same as in Example 4.

[0127] Preparation of solid polymer electrolyte membrane material: In a glove box (H2O < 0.1 ppm, O2 < 0.1 ppm), 1.0 g PCMS-4, 1.30 g LiTFSI, and 0.02 g EDK photoinitiator were fully dissolved in 4 g N,N-dimethylformamide to form a uniform, transparent, colorless solution. This solution was cast onto a tetrafluoroethylene mold, and after evaporating the organic solvent in a vacuum oven, it was irradiated with 360 nm ultraviolet light in a glove box for 2 hours until completely cured, thus obtaining the solid polymer electrolyte membrane material, named SPE-7.

[0128] The electrochemical properties of the solid polymer electrolyte membrane material prepared in this embodiment are shown in Tables 2 and 3.

[0129] Example 8: Preparation of photocurable high dielectric constant polysiloxane and solid polymer electrolyte membrane materials

[0130] Preparation of photocurable high dielectric constant polysiloxane: The preparation process is the same as in Example 4.

[0131] Preparation of solid polymer electrolyte membrane material: In a glove box (H2O < 0.1 ppm, O2 < 0.1 ppm), 1.0 g PCMS-4, 1.50 g LiTFSI, and 0.02 g BDK photoinitiator were fully dissolved in 4 g N,N-dimethylformamide to form a uniform, transparent, colorless solution. This solution was cast onto a tetrafluoroethylene mold, and after evaporating the organic solvent in a vacuum oven, it was irradiated with 360 nm ultraviolet light in a glove box for 2 hours until completely cured, thus obtaining the solid polymer electrolyte membrane material, named SPE-8.

[0132] The electrochemical properties of the solid polymer electrolyte membrane material prepared in this embodiment are shown in Tables 2 and 3.

[0133] Example 9: Preparation of photocurable high dielectric constant polysiloxane and solid polymer electrolyte membrane materials

[0134] Preparation of photocurable high dielectric constant polysiloxane: Under N2 protection, 50 g of methylaminopropylcyclosiloxane (Formula II-B) and 0.35 g of (1,1,3,3-tetramethyldisiloxane-1,3-diyl)dipropane-1,3-diyl diacrylate (Formula III-A) were added to a 500 ml three-necked flask, along with 100 g of N,N-dimethylformamide. The mixture was stirred for 10 minutes until homogeneous. The temperature was raised to 70 °C, and 1 g of concentrated H2SO4 was added to the flask using a pipette. After reacting for 48 h, the solvent and catalyst were removed to obtain the polymer shown in I-B (where m is 404 and n is 0), which is the photocurable high dielectric constant polysiloxane, named PNMS.

[0135] In the polymer shown in Formula II-B, a is 4 and b is 0.

[0136] Preparation of solid polymer electrolyte membrane material: In a glove box (H2O < 0.1 ppm, O2 < 0.1 ppm), 1.0 g PNMS, 0.45 g LiTFSI, and 0.02 g BDK photoinitiator were fully dissolved in 4 g N,N-dimethylformamide to form a uniform, transparent, colorless solution. This solution was cast onto a tetrafluoroethylene mold, and after evaporating the organic solvent in a vacuum oven, it was irradiated with 360 nm ultraviolet light in a glove box for 2 hours until completely cured, thus obtaining the solid polymer electrolyte membrane material, named SPE-9.

[0137] The dielectric constant of the photocurable high dielectric constant polysiloxane prepared in this embodiment is shown in Table 1.

[0138] The electrochemical properties of the solid polymer electrolyte membrane material prepared in this embodiment are shown in Tables 2 and 3.

[0139] Example 10: Preparation of photocurable high dielectric constant polysiloxane and solid polymer electrolyte membrane materials

[0140] Preparation of photocurable high dielectric constant polysiloxane: Under N2 protection, 50 g of trifluoropropylmethylcyclotrisiloxane (Formula II-C) and 0.35 g of (1,1,3,3-tetramethyldisiloxane-1,3-diyl)dipropane-1,3-diyldiacrylate (Formula III-A) were added to a 500 ml three-necked flask, along with 100 g of N,N-dimethylformamide. The mixture was stirred for 10 minutes until homogeneous. The temperature was raised to 70 °C, and 1 g of concentrated H2SO4 was added to the flask using a pipette. After reacting for 48 h, the solvent and catalyst were removed to obtain the polymers shown in I-F (where m is 404 and n is 0), which is the photocurable high dielectric constant polysiloxane, named PFMS.

[0141] In the polymer shown in Formula II-C, a is 4 and b is 0.

[0142] Preparation of solid polymer electrolyte membrane material: In a glove box (H2O < 0.1 ppm, O2 < 0.1 ppm), 1.0 g PFMS, 0.45 g LiTFSI, and 0.02 g BDK photoinitiator were fully dissolved in 4 g N,N-dimethylformamide to form a uniform, transparent, colorless solution. This solution was cast onto a tetrafluoroethylene mold, and after evaporating the organic solvent in a vacuum oven, it was irradiated with 360 nm ultraviolet light in a glove box for 2 hours until completely cured, thus obtaining the solid polymer electrolyte membrane material, named SPE-10.

[0143] The dielectric constant of the photocurable high dielectric constant polysiloxane prepared in this embodiment is shown in Table 1.

[0144] The electrochemical properties of the solid polymer electrolyte membrane material prepared in this embodiment are shown in Tables 2 and 3.

[0145] Comparative Example 1: Preparation of photocurable polysiloxane control sample and solid polymer electrolyte membrane material

[0146] Preparation of the photocurable polysiloxane control sample: Under N2 protection, 50 g of octamethylcyclotetrasiloxane (Formula II-A) and 0.6 g of 1,3-bis(3-acryloyloxypropyl)tetramethyldisiloxane (Formula III-A) were added to a 500 ml three-necked flask, along with 100 g of N,N-dimethylformamide. The mixture was stirred for 10 minutes until homogeneous. The temperature was raised to 70 °C, and 1 g of concentrated H2SO4 was added to the three-necked flask using a pipette. After reacting for 48 h, the solvent and catalyst were removed to obtain the polymer shown in I-A, which is the photocurable polysiloxane (molecular weight of 30,000), named PDMS-0.

[0147] In the polymer shown in Formula II-A, a is 0 and b is 4.

[0148] Preparation of solid polymer electrolyte membrane material: In a glove box (H2O < 0.1 ppm, O2 < 0.1 ppm), 1.0 g PDMS-0, 0.45 g LiTFSI, and 0.02 g BDK photoinitiator were fully dissolved in 4 g N,N-dimethylformamide to form a uniform, transparent, colorless solution. This solution was cast onto a tetrafluoroethylene mold, and after evaporating the organic solvent in a vacuum oven, it was irradiated with 360 nm ultraviolet light in a glove box for 2 hours until completely cured, thus obtaining the solid polymer electrolyte membrane material, named SPE-0.

[0149] The dielectric constants of the photocurable polysiloxane control samples prepared in this comparative example are shown in Table 1.

[0150] Comparative Example 2: Preparation of PEO-based solid polymer electrolyte membrane materials

[0151] PEO-based solid polymer electrolyte membrane material: In a glove box (H2O < 0.1 ppm, O2 < 0.1 ppm), 1.0 g of PEO (molecular weight 600,000) and 0.45 g of LiTFSI were fully dissolved in 4 g of anhydrous acetonitrile to form a uniform, transparent, colorless solution. This solution was cast onto a tetrafluoroethylene mold and dried in a vacuum oven at 80 °C for 48 h to completely remove the organic solvent, thus obtaining the solid polymer electrolyte membrane material, named PEO SPE.

[0152] The electrochemical properties of the PEO-based solid polymer electrolyte membrane materials prepared in this comparative example are shown in Tables 2 and 3.

[0153] Table 1. Dielectric constant data of photocurable polysiloxanes in Examples 1-4 and Comparative Example 1

[0154]

[0155]

[0156] As shown in Table 1, the dielectric constant of the photocurable high-dielectric-constant polysiloxane prepared in this application is significantly improved compared to the two comparative examples. In Example 4, the dielectric constant increased from 3.07 to 17.25 compared to Comparative Example 1. This increase in dielectric constant will enhance the polymer's ability to dissolve lithium salts, thereby increasing the number of charge carriers in the system. This result demonstrates that the polysiloxane prepared in this invention has excellent lithium salt dissociation capabilities.

[0157] Table 2. Ionic conductivity data of high-dielectric silicone rubber in Examples 2-10 and Comparative Examples

[0158]

[0159]

[0160] Table 3. Electrochemical stability window data of high-dielectric silicone rubber in Examples 2-10 and Comparative Examples.

[0161] sample Stable potential range (V) Example 1 5.45 Example 2 5.57 Example 3 5.64 Example 4 5.23 Example 5 5.49 Example 6 5.54 Example 7 5.65 Example 8 5.74 Example 9 5.08 Example 10 5.68 Comparative Example 1 5.66 Comparative Example 2 4.32

[0162] As shown in Tables 2 and 3, the ionic conductivity of the solid polymer electrolyte membrane material prepared in this application is significantly improved compared to the solid electrolyte based on PEO matrix. For example, compared with Example 4 and Comparative Example 2, the conductivity at room temperature is 5.2123 × 10⁻⁶. -6 S cm -1 Increased to 8.1873×10 -5 S cm -1 Meanwhile, due to the excellent chemical stability of polysiloxane polymers, the electrochemical stability windows of the solid polymer electrolyte membrane materials prepared in this application are all higher than 5V, exhibiting higher electrochemical stability compared to the PEO system, and are expected to be suitable for high-voltage battery systems.

[0163] Figure 1 The images show the 1H NMR spectra of the photocurable high-dielectric-constant polysiloxanes from Examples 1-4 and the photocurable polysiloxane control sample from Comparative Example 1. In Comparative Example 1, only a Si-CH3 peak is observed at 0.1 ppm, and no other H structures are present in the system. In the spectra of Examples 1-4, the peak at 0.1 ppm is Si-CH3, and the peak at 0.7 ppm is Si- CH2 The peak corresponding to CH2CH2CN, and the peak at 1.7 ppm is Si-CH2. CH2The peak corresponding to CH2CN, and the peak at 2.4 ppm is Si-CH2CH2. CH2 The peak corresponding to CN. As the content of polar groups increases, the peak intensity at 0.1ppm, 0.7ppm, 1.7ppm and 2.4ppm gradually increases, while the peak intensity at 0.1ppm gradually decreases.

[0164] Figure 2 This is a gel permeation chromatogram of the photocurable high dielectric constant polysiloxane of Example 4. The weight-average molecular weight (Mw) of the prepared polymer is 104,900, and the number-average molecular weight (Mn) is 31,600, confirming that the prepared polymer is indeed a polymer.

[0165] Figure 3 The images show the infrared spectra of the photocurable high-dielectric-constant polysiloxanes of Examples 1-4 and the photocurable polysiloxane control sample in Comparative Example 1. The image shows the 1454 cm⁻¹ spectrum. -1 1425cm -1 1346cm -1 The vibrational peaks of -CH2(α), CH2(β), and CH2(γ) in -CH2(α)CH2(β)CH2(γ)CN are assigned at 1180 cm⁻¹. -1 The nearby peaks are attributed to the vibrational peaks of Si-CH2. With increasing polar group content, the peak at 1454 cm⁻¹... -1 1425cm -1 1346cm -1 The peak intensity gradually increases at that point.

[0166] Figure 4 The images show the DSC spectra of the photocurable high-dielectric-constant polysiloxanes of Examples 1-4 and the photocurable polysiloxane control sample in Comparative Example 1. Although Comparative Example 1 has a lower glass transition temperature (-123.65°C), it crystallizes near -50°C. In contrast, the glass transition temperatures of the samples in Examples 1-4 increase with the increase of polar group content, but are all below -60°C. They are all in a highly elastic state within the electrolyte operating temperature range, exhibiting superior performance.

[0167] Figure 5 The image shows the surface morphology of the solid polymer electrolyte membrane material in Example 8. It can be seen that the surface is smooth and flat, without obvious pores, and the curing is complete.

[0168] Figure 6 The image shows the cross-sectional morphology of the solid polymer electrolyte membrane material in Example 8. It can be seen that the thickness of the solid polymer electrolyte membrane is approximately 200 μm-300 μm.

[0169] Figure 7The images show the AC impedance spectra of the solid polymer electrolyte membrane material in Example 4 at different temperatures. As the temperature increases, the intrinsic impedance of the solid polymer electrolyte membrane material gradually decreases. This is because at higher temperatures, the chain segments in the polymer matrix have stronger mobility. Under these conditions, charge carriers move more easily with the directional movement of the chain segments, which manifests as a decrease in impedance and an increase in ionic conductivity in terms of electrochemical performance.

[0170] Figure 8 The electrochemical stability window of the solid polymer electrolyte membrane material in Example 4 was obtained by testing at room temperature. Due to the good chemical stability of polysiloxane, the prepared solid polymer electrolyte membrane material has a wide electrochemical stability window. Figure 9 This is a curved image of the solid polymer electrolyte membrane material from Example 8. (Source: [Image source missing]) Figure 9 It can be seen that the obtained material has good flexibility.

[0171] Figure 10 The thermogravimetric curve is shown for the solid polymer electrolyte membrane material of Example 8. (From...) Figure 10 It can be seen that the obtained material has good heat resistance.

[0172] The embodiments of the present invention have been described above by way of example. However, the scope of protection of the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made by those skilled in the art within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A photocurable polysiloxane comprising at least one polymer having the structure shown in Formula I; Formula I in, R1, R2, and R3 may be the same or different, and are independently selected from C. 1-6 alkyl; R4 is selected from CN, -CH2X, -CH(X)CH3, -CH2CH2X, -CY3, -CH(Y)CH(Y)2, -C(Y)2CH2Y, wherein X is selected from -CN, amino or Cl, and Y is selected from F; Each R5 is either the same or different, and is selected independently from C. 1-6 Alkyl, -C 1-6 Alkyl-acrylate group, -C 1-6 Alkyl-methacrylate or -OC 1-6 Alkyl-C 2-4 Epoxyalkyl; provided that at least one of the R5 groups at each end of the polymer in Formula I is selected from one of the following groups: -C 1-6 Alkyl-acrylate group, -C 1-6 Alkyl-methacrylate or -OC 1-6 Alkyl-C 2-4 Epoxyalkyl; m is any integer between 100 and 500, and n is any integer between 1 and 499.

2. The photocurable polysiloxane according to claim 1, characterized in that, R1, R2, and R3 may be the same or different, and each is independently selected from methyl or ethyl.

3. The photocurable polysiloxane according to claim 1, characterized in that, Each R5 may be the same or different, and is independently selected from methyl, ethyl, -(CH2)3OC(=O)C(CH3)=CH2, -(CH2)3OC(=O)CH=CH2 or -OCH2(CHCH2O), provided that at least one of the R5 groups at both ends of the polymer in Formula I is -(CH2)3OC(=O)C(CH3)=CH2, -(CH2)3OC(=O)CH=CH2 or -OCH2(CHCH2O).

4. The photocurable polysiloxane according to any one of claims 1-3, characterized in that, Polymers having the structure shown in Formula I have any one of the following structures shown in Formula I-A, I-C, I-D, I-E, or I-F: Formula I-A Formula I-C Formula I-D Formula I-E Formula I-F In formulas I-A, I-C, I-D, I-E and IF, m and n each contain the definition described in any one of claims 1-3.

5. The photocurable polysiloxane according to claim 4, characterized in that, In Equation I-A, m is 100 and n is 400; or in Equation I-A, m is 200 and n is 300; or in Equation I-A, m is 300 and n is 200; or in Equation I-A, m is 400 and n is 100; or in Equation I-A, m is 450 and n is 50; or in Equation I-A, m is 103 and n is 309; or m is 198 and n is 198; or m is 297 and n is 99. In Equation I-C, m is 100 and n is 400; or in Equation I-C, m is 200 and n is 300; or in Equation I-C, m is 300 and n is 200; or in Equation I-C, m is 400 and n is 100; or in Equation I-C, m is 450 and n is 50. In Equation I-D, m is 100 and n is 400; or in Equation I-D, m is 200 and n is 300; or in Equation I-D, m is 300 and n is 200. Alternatively, in Equation I-D, m is 400 and n is 100; or in Equation I-D, m is 450 and n is 50. In Equation I-E and IF, m is 100 and n is 400; or in Equation I-E, m is 200 and n is 300; or in Equation I-E, m is 300 and n is 200. Alternatively, in Equation I-E, m is 400 and n is 100; or in Equation I-E, m is 450 and n is 50.

6. The photocurable polysiloxane according to claim 1, characterized in that, The dielectric constant of the polysiloxane is 2-20, and the test conditions are 10. 5 Hz.

7. The method for preparing the photocurable polysiloxane according to any one of claims 1-6, characterized in that, The process includes the following steps: using a cyclosiloxane monomer with polar side chain substitution having the structure shown in Formula II and a compound having the structure shown in Formula III as end-capping agents to carry out a ring-opening polymerization reaction under the action of a catalyst to obtain a polymer with the structure shown in Formula I. Formula II In Formula II, a+b is any integer greater than 2 and less than or equal to 6, and a and b are not 0; R1, R2, R3, and R4 have the definitions described in any one of claims 1-6; Formula III In Formula III, R5 has the definition as described in any one of claims 1-6.

8. The preparation method according to claim 7, characterized in that, Formula II is a cyclosiloxane monomer with polar side chain substitution having the structures shown in Formula II-A and Formula II-C below: Formula II-A Formula II-C In Equation II-A, a is 1 and b is 3; a is 2 and b is 2; a is 3 and b is 1. In Equation II-C, a is 1 and b is 2; a is 2 and b is 1.

9. The preparation method according to claim 7, characterized in that, Compounds having the structure shown in Formula III are compounds having the structure shown in Formula III-A below: Formula III-A.

10. The use of the photocurable polysiloxane according to any one of claims 1-6 in the preparation of solid polymer electrolyte membrane materials for lithium-ion batteries.

11. A solid polymer electrolyte material for lithium-ion batteries, characterized in that, include: The photocurable polysiloxane, lithium salt, and photoinitiator according to any one of claims 1-6.

12. The solid polymer electrolyte material for lithium-ion batteries according to claim 11, characterized in that, The lithium salts are LiNO3, LiClO4, LiBF4, LiAsF6, LiPF6, LiBOB, LiDFOB, LiFSI, LiTFSI, LiSbF6, LiN(C4F9SO2)2, LiCF3CO2, LiAlCl4, and Li2B. 12 F 12 One or more of LiCF3SO3.

13. The solid polymer electrolyte material for lithium-ion batteries according to claim 11, characterized in that, The photoinitiator is one or more of the following: 2,4,6-trimethylbenzoyl)diphenylphosphine oxide, ethyl 2,4,6-trimethylbenzoylphosphonate, 2-methyl-1-[4-methylthiophenyl]-2-morpholinyl-1-propanone, 2-isopropylthioxanthone, ethyl 4-dimethylaminobenzoate, 1-hydroxy-cyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2,2-dimethoxy-2-phenylethyl ketone, or methyl o-benzoylbenzoate.

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