Supramolecular semi-interpenetrating polymer network electrolyte as well as preparation method and application thereof

Abstract

The invention relates to a supramolecular semi-interpenetrating polymer network electrolyte and a preparation method and application thereof.The supramolecular semi-interpenetrating polymer network electrolyte is prepared from, by weight, 150-300 parts of polytetrahydrofuran, 150-300 parts of 18-crown ether-6, 40-60 parts of dicyclohexylmethane 4, 4 '-diisocyanate, 2, 2'-(1, 4-phenyl)-bis [4-(4-hydroxybutyl)-1, 3, 4-trimethyl-1, 3, 4-trimethyl-1, 3, 4-trimethyl-1, 3, 4-trimethyl-1, 3, 4-trimethyl-1, 3, 4-trimethyl-1, 3, 4-trimethyl-1, 3, 4- The composite material is prepared from the following components in parts by weight: 32 to 48 parts of 1, 2-dioxaborolane], 1 to 1.2 parts of a catalyst, 5.5 to 8.5 parts of an end-capping reagent, 1500 to 2500 parts of 1, 3-dioxolame, 500 to 840 parts of lithium bis (trifluoromethylsulfonyl) imide, 23 to 38 parts of scandium trifluoromethanesulfonate and 15 to 25 parts of a cross-linking agent. According to the invention, a functional thermoplastic polyurethane elastomer-rotaxane is introduced into a polydioxolame matrix to form a supramolecular semi-interpenetrating network structure, so that concentration polarization and growth of lithium dendrites can be inhibited, and the cycling stability is improved.

Description

Technical Field

[0001] This application relates to the field of lithium battery technology, and in particular to a supramolecular semi-interpenetrating polymer network electrolyte, its preparation method, and its application. Background Technology

[0002] Pursuing higher energy densities in lithium metal batteries is crucial for next-generation energy storage technologies, especially those requiring over 400 Wh·kg⁻¹. -1 For emerging applications, solid polymer electrolytes are considered a promising development direction due to their ability to replace flammable liquid electrolytes, solve the problem of organic liquid leakage or combustion, and their intrinsic compatibility with lithium metal anodes. However, traditional solid polymer electrolytes still suffer from problems such as low ionic conductivity and insufficient lithium-ion transference number, leading to concentration polarization at the metal anode interface. In addition, solid polymer electrolytes have a narrow electrochemical stability window, are prone to severe oxidative decomposition on the high-voltage cathode side, and can cause lithium dendrite growth on the anode side, which also limits their application in lithium metal batteries.

[0003] Among various solid polymer electrolytes, polyether-based solid electrolytes (such as polyethylene oxide and polydioxane) have attracted widespread research attention due to their low cost, ease of operation, and simple manufacturing process. However, polyether-based solid lithium metal batteries still suffer from problems such as insufficient room temperature ionic conductivity, poor stability of the positive and negative electrode interfaces, and excessive thickness, which in turn affect the actual energy density.

[0004] In recent years, in-situ polymerization technology has become an important method for solving interface problems and improving battery energy density. In-situ polymerization mainly utilizes the ultra-low viscosity of liquid monomers (such as acrylates) to penetrate the micron-sized pores of a highly loaded cathode, thereby constructing a pore-free three-dimensional polydioxane polymer network in situ, shortening the ion diffusion path to the nanometer scale. This process enables molecular-level electrode-electrolyte integration, enhances the contact between active materials, significantly reduces interfacial resistance, improves pore blockage problems, and ultimately increases energy density.

[0005] However, polydioxane has poor electrochemical stability and is prone to oxidative decomposition under high pressure, which leads to a decrease in battery performance and a shortened cycle life. Summary of the Invention

[0006] To improve the cycling stability of electrolytes, this application provides a supramolecular semi-interpenetrating polymer network electrolyte, its preparation method, and its application.

[0007] In a first aspect, this application provides a supramolecular semi-interpenetrating polymer network electrolyte, employing the following technical solution: A supramolecular semi-interpenetrating polymer network electrolyte, comprising the following raw materials in parts by weight: Polytetrahydrofuran 150-300 parts, 18-crown ether-6 150-300 parts, dicyclohexane 4,4'-diisocyanate 40-60 parts, 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaboranecyclopentane] 32-48 parts, catalyst 1-1.2 parts, end-capping agent 5.5-8.5 parts, 1,3-dioxapentane 1500-2500 parts, lithium bis(trifluoromethanesulfonyl)imide 500-840 parts, scandium trifluoromethanesulfonate 23-38 parts, crosslinking agent 15-25 parts.

[0008] By employing the above technical solution, a functional thermoplastic polyurethane elastomer—rotaxane—is introduced into a polydioxolane matrix, forming a supramolecular semi-interpenetrating network structure. This structure not only improves the ionic conductivity and lithium-ion transference number of the electrolyte, suppresses concentration polarization and lithium dendrite growth, but also enhances cycle stability by strengthening interfacial stability. Furthermore, 2,2'-(1,4-phenyl)bis[4-(4-hydroxybutyl)-1,3,2-dioxolanecyclopentane] can form a glassy protective layer at high temperatures, thereby achieving intrinsic flame retardancy and improving electrolyte safety.

[0009] The weight ratio of the dicyclohexane 4,4'-diisocyanate and 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaboranecyclopentane] is (5-7):4.

[0010] This application employs a specific ratio of dicyclohexane 4,4'-diisocyanate and 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaborhexacyclopentane] to ensure an optimal balance between the rigid cyclohexyl backbone provided by dicyclohexane 4,4'-diisocyanate and the flexible long-chain segments and key borate functional groups introduced by 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaborhexacyclopentane], thereby achieving simultaneous growth in electrolyte mechanical strength, chain segment mobility, and electrochemical function. Specifically, dicyclohexane 4,4'-diisocyanate can enhance the stability of the three-dimensional network and suppress dendrite growth; 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaborhexacyclopentane] can promote chain segment mobility and improve ion transport capacity through its long flexible segments. In addition, 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaborhecyclopentane] can provide borate ester groups to anchor bis(trifluoromethanesulfonyl)imine anions, thereby increasing the lithium-ion transference number, and decomposes into a boron oxide protective layer at high temperatures, improving the safety of the electrolyte.

[0011] Preferably, the weight ratio of the polytetrahydrofuran to 18-crown ether-6 is 1:1.

[0012] Optionally, the weight ratio of the polytetrahydrofuran, dicyclohexane 4,4'-diisocyanate and 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaboranecyclopentane] is 1:(0.20-0.36):(0.13-0.24).

[0013] By adopting the above technical solution, this application uses a specific ratio of polytetrahydrofuran, dicyclohexane 4,4'-diisocyanate and 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaborhexacyclopentane] to optimize the balance between rigid backbone and flexible segments in the supramolecular semi-interpenetrating network structure, thereby achieving a synergistic improvement in ionic conductivity, lithium-ion transference number, mechanical strength and cycle stability.

[0014] Optionally, the preparation steps of 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaborhexacyclopentane] include: mixing 1,4-phenyldiboronic acid and 1,2,6-hexanetriol, adding a first solvent to dissolve them, then adding magnesium sulfate, stirring evenly, filtering, removing the first solvent under reduced pressure, adding n-hexane to precipitate, filtering, and obtaining 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaborhexacyclopentane].

[0015] By adopting the above technical solution, 1,4-phenylenediboric acid and 1,2,6-hexanetriol undergo an esterification reaction to form two borate ester rings, which are the core functional groups for subsequently exerting Lewis acidity, coordinating with anions, increasing lithium ion transference number, and participating in the formation of a stable electrolyte interface film.

[0016] Optionally, the first solvent is tetrahydrofuran.

[0017] Optionally, the catalyst is dibutyltin dilaurate; the end-capping agent is 1-isocyanate-3,5-bis(trifluoromethyl)benzene; and the crosslinking agent is 2,4,6-tris(ethylene oxide-2-ylmethoxy)-1,3,5-triazine.

[0018] By adopting the above technical solution, this application uses dibutyltin dilaurate as a catalyst, which can efficiently catalyze the addition polymerization reaction of isocyanate and hydroxyl groups, ensuring the controllable and efficient synthesis of the high molecular weight structure of thermoplastic polyurethane elastomer-rotaxane; 1-isocyanate-3,5-bis(trifluoromethyl)benzene, as a capping agent, not only effectively controls the molecular weight of the polymer, but its rich trifluoromethyl group can also preferentially reduce at the lithium metal anode interface, participate in the construction of a solid electrolyte interface film rich in lithium fluoride, and thus effectively suppress lithium dendrites and side reactions; 2,4,6-tris(ethylene oxide-2-ylmethoxy)-1,3,5-triazine, as a multifunctional epoxy crosslinking agent, undergoes cationic ring-opening polymerization with polydioxolane under the catalysis of scandium trifluoromethanesulfonate to form a dense and stable three-dimensional crosslinking network, which not only significantly improves the mechanical strength of the electrolyte to suppress dendrite penetration, but its own triazine ring structure also enhances the thermal and chemical stability of the system. In addition, 2,4,6-tris(ethylene oxide-2-ylmethoxy)-1,3,5-triazine belongs to the triazine class of flame retardants, which release nitrogen to dilute flammable gases and improve the safety of electrolytes.

[0019] Optionally, the preparation steps of the 2,4,6-tris(ethylene oxide-2-ylmethoxy)-1,3,5-triazine include: adding a second solvent and glycidol to sodium hydride, mixing them evenly, then adding cyanuric chloride, mixing evenly, heating under reflux, cooling, filtering, separating and purifying to obtain 2,4,6-tris(ethylene oxide-2-ylmethoxy)-1,3,5-triazine.

[0020] By adopting the above technical solution, this application uses a stepwise Williamson ether synthesis method to prepare 2,4,6-tris(ethylene oxide-2-ylmethoxy)-1,3,5-triazine, which can effectively suppress the ring-opening side reaction of epoxy groups and ensure the integrity of the functional groups of the final product. Its three epoxy groups can undergo synergistic ring-opening polymerization with polydioxopentane ring chains under scandium salt catalysis to form a dense, uniform and stable three-dimensional interpenetrating network, which significantly enhances the mechanical strength and electrochemical stability of solid electrolytes.

[0021] Optionally, the second solvent is tetrahydrofuran.

[0022] Secondly, this application provides a method for preparing a supramolecular semi-interpenetrating polymer network electrolyte, employing the following technical solution: A method for preparing a supramolecular semi-interpenetrating polymer network electrolyte includes the following steps: S1. Preparation of pseudorotaxane: Polytetrahydrofuran and 18-crown ether-6 are mixed, heated and stirred until homogeneous to obtain pseudorotaxane; S2. Preparation of thermoplastic polyurethane elastomer-rotaxane: The pseudorotaxane was cooled, and dicyclohexane 4,4'-diisocyanate, catalyst and third solvent were added and stirred evenly. Then 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaborhecyclopentane] and catalyst were added and stirred evenly. 1-isocyanate-3,5-bis(trifluoromethyl)benzene was added and mixed evenly. The mixture was cooled, and the third solvent was removed by rotary evaporation. The mixture was purified to obtain thermoplastic polyurethane elastomer-rotaxane. S3. Preparation of precursor solution: Add crosslinking agent, scandium trifluoromethanesulfonate, 1,3-dioxolane and lithium bis(trifluoromethanesulfonyl)imide to thermoplastic polyurethane elastomer-rotaxane, mix and stir evenly to obtain precursor solution; S4. Preparation of supramolecular polymer semi-interpenetrating network electrolyte: The precursor solution is polymerized in situ under argon atmosphere to obtain the supramolecular polymer semi-interpenetrating network electrolyte.

[0023] By adopting the above technical solution, this application first assembles polytetrahydrofuran and 18-crown ether-6 through hydrogen bonding to form pseudorotaxane, laying a sliding supramolecular structural foundation for the entire system. Then, by adding diisocyanate, boron-containing chain extender and end-capping agent stepwise, a multifunctional thermoplastic polyurethane elastomer-rotaxane integrating supramolecular sliding rings, anionic anchoring sites and interface modification groups is synthesized. Finally, through in-situ polymerization, 1,3-dioxolane and crosslinking agent are crosslinked under scandium trifluoromethanesulfonate catalysis to form a rigid three-dimensional network, which interpenetrates with the flexible thermoplastic polyurethane elastomer-rotaxane chain to form a stable semi-interpenetrating network structure, greatly reducing interfacial resistance.

[0024] Optionally, the solvent is tetrahydrofuran.

[0025] Optionally, in S1, the heating temperature is 80-100℃.

[0026] Optionally, in step S2, the first cooling temperature is 50-70°C, the second cooling temperature is 20-28°C, and the third solvent is tetrahydrofuran.

[0027] Optionally, in S4, the reaction temperature for in-situ polymerization is 50-70°C.

[0028] Optionally, S1, S2, S3 and S4 are all performed in a glove box filled with argon gas.

[0029] Thirdly, this application provides an application of a supramolecular semi-interpenetrating polymer network electrolyte, which adopts the following technical solution: an application of a supramolecular semi-interpenetrating polymer network electrolyte in lithium metal batteries.

[0030] Fourthly, this application provides a lithium battery, wherein the positive electrode is one of a lithium iron phosphate electrode sheet and a lithium nickel cobalt manganese electrode sheet, the negative electrode is metallic lithium, and the electrolyte is a supramolecular semi-interpenetrating polymer network electrolyte.

[0031] In summary, this application includes at least one of the following beneficial technical effects: 1. This application introduces a functional thermoplastic polyurethane elastomer, rotaxane, into a polydioxolane matrix to form a supramolecular semi-interpenetrating network structure. This structure not only improves the ionic conductivity and lithium-ion transference number of the electrolyte and inhibits concentration polarization and lithium dendrite growth, but also enhances electrochemical stability by strengthening interfacial stability. 2. This application, by employing a specific ratio of polytetrahydrofuran and 18-crown ether-6, can help promote the formation of pseudorotaxane structures, achieve hydrogen bond self-assembly, construct a stable supramolecular framework, thereby enhancing the mechanical strength and spatial confinement of the polymer network, and thus improving the ion transport capacity and interfacial stability of the electrolyte. 3. By employing a specific ratio of dicyclohexane 4,4'-diisocyanate and 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaborhexacyclopentane], this application ensures an optimal balance between the rigid cyclohexyl skeleton provided by dicyclohexane 4,4'-diisocyanate and the flexible long-chain segments and key borate ester functional groups introduced by 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaborhexacyclopentane], thereby achieving simultaneous growth in electrolyte mechanical strength, chain mobility, and electrochemical function. Attached Figure Description

[0032] Figure 1 This is a flowchart illustrating the preparation of a supramolecular semi-interpenetrating polymer network electrolyte in the embodiments of this application. PTHF: polytetrahydrofuran; 18C6: 18-crown ether-6; HMDI, dicyclohexane 4,4'-diisocyanate; HDB, 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaborane]; TFBI, 1-isocyanate-3,5-bis(trifluoromethyl)benzene; DBTDL, dibutyltin dilaurate; DOL, 1,3-dioxapentane; TPU-rotaxane, thermoplastic polyurethane elastomer-rotaxane; LiTFSI, lithium bis(trifluoromethanesulfonylimide); Sc(OTF)3, scandium trifluoromethanesulfonate; Figure 2 This diagram illustrates the synthesis and characterization of the thermoplastic polyurethane elastomer-rotaxane in the embodiments of this application. Figure 2 a represents the synthesis step of thermoplastic polyurethane elastomer-rotaxane; Figure 2 b is the 1H NMR spectrum of thermoplastic polyurethane elastomer-rotaxane. 1Characterized by ¹H NMR. Since the chemical shift value of 18C6 changed from 7.0 ppm to 9.5 ppm (b, c→d), the H portion of NH in the thermoplastic polyurethane elastomer directly proves that 18C6 is nested within the thermoplastic polyurethane elastomer. Figure 2 c represents the nuclear Overhausen spectroscopy (NOESY) characterization of the thermoplastic polyurethane elastomer-rotaxane. The NOESY signal within the rectangular dashed box indicates a spatial proximity between the protons in 18C6 and the NH bonds in TPU, directly proving that 18C6 is nested within TPU. Figure 2 d represents the molecular weight characterization of thermoplastic polyurethane elastomer-rotaxane; Figure 3 This is a lithium-ion transport number diagram for the supramolecular semi-interpenetrating polymer network electrolyte in Example 2 of this application; SSNE: supramolecular semi-interpenetrating polymer network electrolyte; Figure 4 This is a diagram of the oxidation potential of the supramolecular semi-interpenetrating polymer network electrolyte in Example 2 of this application; Figure 5 The electrochemical impedance spectroscopy spectra of the supramolecular semi-interpenetrating polymer network electrolyte in Example 2 of this application at different temperatures; Figure 6 This is a comparison graph showing the cycle performance of the LFP||SSNE||Li battery and the LFP||PDOL||Li battery in Example 2 of this application at 1C and 4.0V. Figure 7 This is a comparison graph showing the cycle performance of the NCM811||SSNE||Li battery and the NCM811||PDOL||Li battery in Embodiment 2 of this application at 1C and 4.0V. Detailed Implementation

[0033] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0034] This application designs a supramolecular semi-interpenetrating polymer network electrolyte, comprising the following raw materials in parts by weight: Polytetrahydrofuran 150-300 parts, 18-crown ether-6 150-300 parts, dicyclohexane 4,4'-diisocyanate 40-60 parts, 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaboranecyclopentane] 32-48 parts, catalyst 1-1.2 parts, end-capping agent 5.5-8.5 parts, 1,3-dioxapentane 1500-2500 parts, lithium bis(trifluoromethanesulfonyl)imide 500-840 parts, scandium trifluoromethanesulfonate 23-38 parts, crosslinking agent 15-25 parts.

[0035] A method for preparing a supramolecular semi-interpenetrating polymer network electrolyte includes the following steps: S1. Preparation of pseudorotaxane: Polytetrahydrofuran and 18-crown ether-6 are mixed, heated to 80-100℃, and stirred for 2-4 hours to obtain pseudorotaxane; S2. Preparation of thermoplastic polyurethane elastomer-rotaxane: The pseudorotaxane was cooled to 50-70℃, and dicyclohexane 4,4'-diisocyanate, catalyst and third solvent were added. The mixture was stirred for 3-5 h, then 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaborhecyclopentane] and catalyst were added. The mixture was stirred for 3-5 h, then 1-isocyanate-3,5-bis(trifluoromethyl)benzene was added. The mixture was mixed evenly, cooled to 20-28℃, the solvent was evaporated to remove the solvent, dried at 50-70℃, and purified by dialysis with a 2000 Dalton membrane for 1-2 days to obtain thermoplastic polyurethane elastomer-rotaxane. S3. Preparation of precursor solution: Add crosslinking agent, scandium trifluoromethanesulfonate, 1,3-dioxolane and lithium bis(trifluoromethanesulfonyl)imide to thermoplastic polyurethane elastomer-rotaxane, mix and stir for 3-5 h to obtain precursor solution; S4. Preparation of supramolecular polymer semi-interpenetrating network electrolyte: The precursor solution is placed in an argon atmosphere and polymerized in situ at 50-70℃. After standing for 12-24 hours, a supramolecular polymer semi-interpenetrating network electrolyte is obtained.

[0036] All raw materials used in the embodiments of this application are commercially available, wherein: Polytetrahydrofuran, number average molecular weight 2000, Shanghai Maclean Biochemical Technology Co., Ltd. 18-Crown Ether-6, Shanghai Maclean Biotechnology Co., Ltd.; Dicyclohexamethane 4,4'-diisocyanate, Shanghai Aladdin Biochemical Technology Co., Ltd.; 1,4-Phenylatedorboic acid, Shanghai Aladdin Biochemical Technology Co., Ltd.; 1,2,6-Hexanetriol, Shanghai Aladdin Biochemical Technology Co., Ltd.; Dibutyltin dilaurate, Shanghai Aladdin Biochemical Technology Co., Ltd.; Lithium bis(trifluoromethanesulfonyl)imide, Shanghai Aladdin Biochemical Technology Co., Ltd.; Lithium metal, 50μm thickness, Tianjin Zhongneng Lithium Industry Co., Ltd. 1,3-Dioxolane, Shanghai Maclean Biochemical Technology Co., Ltd. Scandium trifluoromethanesulfonate, Shanghai Maclean Biochemical Technology Co., Ltd.; Cyanide, Shanghai Aladdin Biochemical Technology Co., Ltd.; Glycerin, Shanghai Aladdin Biochemical Technology Co., Ltd.; Sodium hydride, Shanghai Aladdin Biochemical Technology Co., Ltd.; Tetrahydrofuran, water ≤50ppm, Shanghai Aladdin Biochemical Technology Co., Ltd.; 1-Isocyano-3,5-bis(trifluoromethyl)benzene, Shanghai Aladdin Biochemical Technology Co., Ltd.; 1,4-Butanediol, Shanghai Maclean Biochemical Technology Co., Ltd.; Trimethylolpropane triglycidyl ether, Shanghai Maclean Biochemical Technology Co., Ltd.; tert-Butylphenol, Shanghai Maclean Biochemical Technology Co., Ltd. Zinc trifluoromethanesulfonate, Shanghai Aladdin Biochemical Technology Co., Ltd.; Lithium iron phosphate, Shanghai Maclean Biochemical Technology Co., Ltd. Lithium, nickel, cobalt, and manganese; Shanghai Aladdin Biochemical Technology Co., Ltd. Acetylene black, Shanghai Aladdin Biochemical Technology Co., Ltd.; Polyvinylidene fluoride, Shanghai Maclean Biochemical Technology Co., Ltd.; 1-Methyl-2-pyrrolidone, Shanghai Aladdin Biochemical Technology Co., Ltd. Specific Implementation

[0037] Preparation Example 1 The preparation of 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaborhecyclopentane] is carried out using the following reaction formula: The specific preparation steps are as follows: 25 mmol of 1,4-phenyldiboronic acid and 55 mmol of 1,2,6-hexanetriol were mixed, and 50 mL of anhydrous tetrahydrofuran was added to dissolve them. Then, 10 g of magnesium sulfate was added, and the mixture was stirred for 24 h. After filtration, the solvent was removed under reduced pressure, and 150 mL of n-hexane was added to precipitate the mixture. After filtration, 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaboranecyclopentane] (8.3 g, yield 91.7%) was obtained. 1 HNMR, carbon nuclear magnetic resonance (NMR) 13 CNMR and solid-state boron nuclear magnetic resonance (CMR) 11The product was characterized by BNMR. 1 HNMR (CDCl3, 400MHz), δ7.78 (s, 4H), 4.55 (m, 2H), 4.40 (t, J1=J2=6Hz, 2H), 3.92 (t , J1=J2=6Hz, 2H), 3.63 (t, J1=4Hz, 4H), 1.72 (m, 2H), 1.60 (m, 8H), 1.45ppm (m, 2H). 13 CNMR (CDCl3, 100 MHz): δ 134.0, 77.5, 71.1, 62.5, 35.8, 32.4 and 21.3 ppm. Due to quadrupole relaxation, carbon adjacent to boron was not detected. 11 BNMR (CDCl3, 128MHz), δ30.0ppm.

[0038] Preparation Example 2 Preparation of 2,4,6-tris(ethylene oxide-2-ylmethoxy)-1,3,5-triazine, the preparation reaction formula is as follows: The specific preparation steps are as follows: 4 mmol of sodium hydride was cooled, and 5 ml of tetrahydrofuran and 3.5 mmol of glycidol were slowly added dropwise. The mixture was stirred for 6 h, then 1 mmol of cyanuric chloride was added, and the mixture was stirred for 3 h. The mixture was refluxed at 70 °C for 12 h, then cooled to 28 °C, filtered, and purified to obtain 2,4,6-tris(ethylene oxide-2-ylmethoxy)-1,3,5-triazine (150 mg, yield 50%). 1 HNMR, 13 The products were characterized by CNMR and high-resolution mass spectrometry (HRMS). 1 HNMR (CDCl3, 500MHz), δ4.59 (dd, J=12.0, 3.3Hz, 1H), 4.26 (dd, J=12.0, 6.1Hz, 1H ), 3.30 (dq, J=6.5, 3.2Hz, 1H), 2.82 (t, J=4.5Hz, 1H), 2.66 (dd, J=4.9, 2.6Hz, 1H). 13 CNMR (CDCl3, 126MHz), δ 172.85, 69.01, 49.01, 44.64. HRMS: calculated value 297.09, measured value [M+H]+298.10.

[0039] Example 1 200 mg of polytetrahydrofuran and 200 mg of 18-crown ether-6 were mixed, heated to 80 °C, and stirred for 4 h to obtain pseudorotaxane. The pseudorotaxane was cooled to 50 °C, and 40 mg of dicyclohexane 4,4'-diisocyanate, 0.5 mg of dibutyltin dilaurate and 800 mg of tetrahydrofuran were added. The mixture was stirred for 5 h, and then 32 mg of 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaborane] and 0.5 mg of dibutyltin dilaurate obtained in Preparation Example 1 were added. The mixture was stirred for 5 h, and then 5.5 mg of 1-isocyanate-3,5-bis(trifluoromethyl)benzene was added. The mixture was mixed evenly and cooled to 20 °C. The solvent was removed by evaporation at ℃, dried at 50℃, and purified by dialysis using a 2000 Dalton membrane for 1 day to obtain thermoplastic polyurethane elastomer-rotaxane. 2500 mg of 1,3-dioxolane, 38 mg of scandium trifluoromethanesulfonate, 840 mg of lithium bis(trifluoromethanesulfonylimide), and 25 mg of 2,4,6-tris(ethylene oxide-2-ylmethoxy)-1,3,5-triazine obtained in Preparation Example 2 were added to the thermoplastic polyurethane elastomer-rotaxane and mixed. The mixture was stirred for 5 h to obtain a precursor solution. The precursor solution was placed under argon atmosphere and polymerized in situ at 50℃. After standing for 24 h, a supramolecular polymer semi-interpenetrating network electrolyte was obtained. The flow chart of the prepared supramolecular semi-interpenetrating polymer network electrolyte is shown below. Figure 1 As shown.

[0040] Example 2 250 mg of polytetrahydrofuran and 250 mg of 18-crown ether-6 were mixed, heated to 90 °C, and stirred for 3 h to obtain pseudorotaxane. The pseudorotaxane was cooled to 60 °C, and 50 mg of dicyclohexane 4,4'-diisocyanate, 0.5 mg of dibutyltin dilaurate, and 900 mg of tetrahydrofuran were added. The mixture was stirred for 4 h, and then 40 mg of 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaborane] and 0.5 mg of dibutyltin dilaurate obtained in Preparation Example 1 were added. The mixture was stirred for 4 h, and then 7 mg of 1-isocyanate-3,5-bis(trifluoromethyl)benzene was added. The mixture was mixed thoroughly and cooled to 24 °C. The solvent was removed by evaporation, and the product was dried at 60°C and purified by dialysis using a 2000 Dalton membrane for 1.5 days to obtain thermoplastic polyurethane elastomer-rotaxane. 2000 mg of 1,3-dioxolane, 30 mg of scandium trifluoromethanesulfonate, 20 mg of 2,4,6-tris(ethylene oxide-2-ylmethoxy)-1,3,5-triazine obtained in Preparation Example 2, and 670 mg of lithium bis(trifluoromethanesulfonylimide) were added to the thermoplastic polyurethane elastomer-rotaxane and mixed. The mixture was stirred for 4 hours to obtain a precursor solution. The precursor solution was placed under argon atmosphere and polymerized in situ at 60°C. After standing for 18 hours, a supramolecular polymer semi-interpenetrating network electrolyte was obtained.

[0041] Example 3 300 mg of polytetrahydrofuran and 300 mg of 18-crown ether-6 were mixed, heated to 100 °C, and stirred for 2 h to obtain pseudorotaxane. The pseudorotaxane was cooled to 70 °C, and 60 mg of dicyclohexane 4,4'-diisocyanate, 0.6 mg of dibutyltin dilaurate, and 900 mg of tetrahydrofuran were added. The mixture was stirred for 3 h, and then 48 mg of 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaborane] and 0.6 mg of dibutyltin dilaurate obtained in Preparation Example 1 were added. The mixture was stirred for 3 h, and then 8.5 mg of 1-isocyanate-3,5-bis(trifluoromethyl)benzene was added. The mixture was mixed evenly and cooled to 2 °C. The solvent was removed by evaporation at 8℃, dried at 70℃, and purified by dialysis with a 2000 Dalton membrane for 2 days to obtain thermoplastic polyurethane elastomer-rotaxane. 1500 mg of 1,3-dioxolane, 23 mg of scandium trifluoromethanesulfonate, 15 mg of 2,4,6-tris(ethylene oxide-2-ylmethoxy)-1,3,5-triazine obtained in Preparation Example 2, and 500 mg of lithium bis(trifluoromethanesulfonylimide) were added to the thermoplastic polyurethane elastomer-rotaxane and mixed. The mixture was stirred for 3 hours to obtain a precursor solution. The precursor solution was placed under argon atmosphere and polymerized in situ at 70℃. After standing for 12 hours, a supramolecular polymer semi-interpenetrating network electrolyte was obtained.

[0042] The supramolecular polymer semi-interpenetrating network electrolytes obtained in Examples 1-3 were tested for ionic conductivity, ion transport number, electrochemical window, and capacity retention after 300 cycles. The test items and methods are as follows: Ionic conductivity: The ionic conductivity of the electrolyte was measured at 30℃ using the AC impedance method. Ionic conductivity = sample thickness / (contact area between sample and steel sheet × intrinsic impedance of sample).

[0043] Ion transport number: The lithium-ion transport number (t) was determined by chronoamperometry and electrochemical impedance spectroscopy. Li+ First, the Li0|electrolyte|Li0 battery was assembled: two lithium foils were placed in the battery case, and 40 μl of supramolecular semi-interpenetrating polymer network electrolyte was dropped onto the separator (50 μm thick). Then, the battery was sealed in a 2016-type button cell under argon atmosphere (oxygen ≤ 0.01 ppm, water ≤ 0.01 ppm). Next, the prepared Li0|electrolyte|Li0 battery was subjected to potentiostatic polarization testing at an applied voltage of 10 mV. The lithium-ion transport number was calculated using the Bruce-Vincent-Evans equation. Where I0 is the initial current, I ss Represents steady-state current. and These are the initial charge transfer resistance and the steady-state charge transfer resistance, respectively, and ΔV is the applied polarization voltage.

[0044] Electrochemical window: The inflection point at which the current increases dramatically when measured by linear sweep voltammetry at a voltage of 0-6V and a boost rate of 0.1V / s is the maximum withstand voltage.

[0045] Cyclic stability: at 25℃, 1C, high rate, 0.5mA / cm 2 At current density and 4.0V, the capacity retention of batteries prepared with supramolecular semi-interpenetrating polymer network electrolyte and poly(1,3-dioxolane) electrolyte and lithium iron phosphate or lithium nickel cobalt manganese electrode sheets was tested after 900 cycles.

[0046] Preparation of LFP||SSNE||Li battery: Lithium iron phosphate, acetylene black, and polyvinylidene fluoride were ground and mixed at a mass ratio of 8:1:1. 50% (by weight) of 1-methyl-2-pyrrolidone (by weight of lithium iron phosphate) was added, and the mixture was stirred for 20 min to obtain a lithium iron phosphate slurry. The lithium iron phosphate slurry was coated onto aluminum foil and dried at 80 °C and -0.8 MPa for 12 h to obtain a lithium iron phosphate electrode sheet. Using the lithium iron phosphate electrode sheet as the positive electrode and metallic lithium as the negative electrode, a supramolecular polymer semi-interpenetrating network electrolyte was assembled into a 2016-type button cell to obtain the LFP||SSNE||Li battery.

[0047] Preparation of NCM811||SSNE||Li Battery: Lithium nickel cobalt manganese, acetylene black, and polyvinylidene fluoride were mixed in a molar ratio of 8:1:1. 50% (by molar fraction) of 1-methyl-2-pyrrolidone was added, and the mixture was stirred for 20 min to obtain a lithium nickel cobalt manganese slurry. The slurry was coated onto aluminum foil and dried at 80 °C and -0.8 MPa for 12 h to obtain a lithium nickel cobalt manganese electrode sheet. Using the lithium nickel cobalt manganese electrode sheet as the positive electrode and metallic lithium as the negative electrode, combined with a supramolecular polymer semi-interpenetrating network electrolyte, the NCM811||SSNE||Li battery was assembled in a 2016-type button cell to obtain the battery.

[0048] Preparation of LFP||PDOL||Li batteries and NCM811||PDOL||Li batteries: 2000 mg of 1,3-dioxolane and 670 mg of lithium bis(trifluoromethanesulfonyl)imide were mixed and stirred for 8 h. 30 mg of scandium trifluoromethanesulfonate was added and stirred until the initiator was completely dissolved. The mixture was then injected into a battery case and polymerized in situ at 60 °C. After standing for 18 h, poly(1,3-dioxolane) electrolyte was obtained. All the above steps were carried out in an argon-filled glove box. Using lithium iron phosphate electrode sheets as the positive electrode and lithium metal as the negative electrode, the poly(1,3-dioxolane) electrolyte was assembled into a 2016-type button cell to obtain the LFP||PDOL||Li battery. The preparation of the lithium iron phosphate electrode sheets was the same as described above. A lithium nickel cobalt manganese electrode sheet was used as the positive electrode, and metallic lithium was used as the negative electrode. Combined with a poly(1,3-dioxolane) electrolyte, the electrodes were assembled into a 2016-type button cell to obtain an NCM811||PDOL||Li battery. The preparation of the lithium nickel cobalt manganese electrode sheet was the same as described above.

[0049] The test results of Examples 1-3 obtained according to the above test methods are shown in Table 1: Table 1. Performance testing of supramolecular polymer semi-interpenetrating network electrolytes in Examples 1-3 detection indicators Example 1 Example 2 Example 3 Ionic conductivity (mS / cm) 0.16 0.18 0.14 Ion transport number 0.70 0.73 0.68 Electrochemical window (V) 4.1 4.5 4.3 Capacity retention rate after 300 cycles (%) 83.4 85.0 78.8 From Examples 1-3, Figure 3-7As shown in Table 1, the battery prepared with the supramolecular polymer semi-interpenetrating network electrolyte of Example 2 of this application has an ionic conductivity of 0.18, an ion transference number of 0.73, an electrochemical window of 4.5V, and a capacity retention of 78.8-85% after 300 cycles. The battery prepared with the poly(1,3-dioxolane) electrolyte has a capacity retention of 70.1% after 300 cycles, indicating that the supramolecular polymer semi-interpenetrating network electrolyte of this application has excellent cycle stability and ion transference number. Polytetrahydrofuran and 18-crown-6 can be assembled via hydrogen bonding to form pseudorotaxane, and through a boron-containing crosslinking agent and a fluorine-containing end-capping agent, a rigid, functionalized thermoplastic polyurethane elastomer-rotaxane is finally synthesized. Mixing thermoplastic polyurethane elastomer-rotaxane with 1,3-dioxolane, lithium salt, crosslinking agent, and initiator allows 1,3-dioxolane to penetrate into the thermoplastic polyurethane elastomer-rotaxane network and form a chemically crosslinked polydioxolane polymer network through in-situ ring-opening polymerization, ultimately forming a supramolecular polymer semi-interpenetrating network. In this network, the functional thermoplastic polyurethane elastomer-rotaxane acts as the backbone, providing mechanical support and toughness; the polydioxolane provides a continuous matrix with strong chain segment mobility, facilitating lithium-ion transport. Their synergistic effect can suppress dendrite growth and improve electrochemical stability while ensuring high lithium-ion migration. Excessive proportions of polytetrahydrofuran and 18-crown-6 may lead to decreased chain segment mobility, resulting in a reduction in overall ionic conductivity. An excessively high proportion of 1,3-dioxolane can lead to insufficient electrolyte mechanical strength, failing to effectively suppress dendrite growth and resulting in reduced electrochemical and cycling stability.

[0050] Comparative Example 1 The difference between this comparative example and Example 2 is that in this comparative example, the mass of 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaborane] in Example 2 is replaced with dicyclohexane 4,4'-diisocyanate.

[0051] Comparative Example 2 The difference between this comparative example and Example 2 is that in this comparative example, the dicyclohexane 4,4'-diisocyanate in Example 2 is replaced by 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaboranecyclopentane].

[0052] The supramolecular polymer semi-interpenetrating network electrolytes obtained in Example 2 and Comparative Examples 1-2 were tested for ionic conductivity, ion transport number, electrochemical window, and capacity retention after 300 cycles. The results are shown in Table 2. Table 2. Performance testing of supramolecular polymer semi-interpenetrating network electrolytes in Examples 2 and Comparative Examples 1-2 detection indicators Example 2 Comparative Example 1 Comparative Example 2 Ionic conductivity (mS / cm) 0.18 0.12 0.14 Ion transport number 0.73 0.49 0.67 Electrochemical window (V) 4.5 4.1 4.2 Capacity retention rate after 300 cycles (%) 85.0 59.6 68.1 As shown in Example 2, Comparative Examples 1-2, and Table 2, the supramolecular polymer semi-interpenetrating network electrolyte of Example 2 of this application exhibits an ionic conductivity of 0.18 mS / cm, an ion transference number of 0.73, an electrochemical window of 4.5 V, and a capacity retention of 85.0% after 300 cycles, all significantly superior to electrolytes prepared using dicyclohexane 4,4'-diisocyanate or 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaborhecyclopentane]. The use of 2,4,6-tris(ethylene oxide-2-ylmethoxy)-1,3,5-triazine as a crosslinking agent combines rigid support, thermochemical stability, and high reactivity, contributing to the construction of a robust semi-interpenetrating structure. Among them, the 1,3,5-triazine ring as the core can form a denser and stronger three-dimensional cross-linked network after polymerization, providing the electrolyte with extremely high mechanical modulus and strength, and effectively suppressing lithium dendrite penetration. The triazine ring has excellent thermal stability and chemical inertness, which makes the electrolyte more stable at high temperatures and less prone to decomposition, thereby improving the electrochemical window. In contrast, trimethylolpropane triglycidyl ether, with its flexible aliphatic chain as the core, forms a cross-linked network with insufficient rigidity and weak mechanical strength. Moreover, the aliphatic chain structure is more prone to oxidative decomposition under high pressure, leading to accelerated capacity decay in the later stages.

[0053] Examples 4-5 Based on Example 2, except for the weight ratio of dicyclohexane 4,4'-diisocyanate and 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaborhexacyclopentane], the other components and preparation methods are the same as in Example 2, and the total weight of dicyclohexane 4,4'-diisocyanate and 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaborhexacyclopentane] remains unchanged.

[0054] Example 4 The difference between this embodiment and Example 2 is that the weight ratio of dicyclohexane 4,4'-diisocyanate and 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaboranecyclopentane] in this embodiment is 6:4.

[0055] Example 5 The difference between this embodiment and Example 2 is that the weight ratio of dicyclohexane 4,4'-diisocyanate and 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaboranecyclopentane] in this embodiment is 7:4.

[0056] The supramolecular polymer semi-interpenetrating network electrolytes obtained in Examples 2 and 4-5 were tested for ionic conductivity, ion transport number, and capacity retention after 300 cycles. The results are shown in Table 3. Table 3. Performance testing of supramolecular polymer semi-interpenetrating network electrolytes in Examples 2 and 4-5. detection indicators Example 2 Example 4 Example 5 Ionic conductivity (mS / cm) 0.18 0.22 0.19 Ion transport number 0.73 0.77 0.75 Capacity retention rate after 300 cycles (%) 85.0 88.2 86.8 As shown in Examples 2, 4-5, and Table 3, the supramolecular polymer semi-interpenetrating network electrolyte of Example 4 has an ionic conductivity of 0.22, an ion transference number of 0.77, and a capacity retention of 88.2% after 300 cycles, which is superior to Examples 2 and 5. This application uses a specific ratio of dicyclohexane 4,4'-diisocyanate and 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaborhecyclopentane], which can undergo a nucleophilic addition reaction under the action of a catalyst to generate urethane bonds. This not only imparts high rigidity and ion transport capability but also further enhances the stability of the polymer network and improves the cycle capacity retention.

[0057] Examples 6-7 Based on Example 4, except for the weight of polytetrahydrofuran and 18-crown ether-6, the other components and preparation methods are the same as in Example 4.

[0058] Example 6 The difference between this embodiment and embodiment 4 is that the weight of polytetrahydrofuran in this embodiment is 200 mg, and the weight of 18-crown ether-6 is 200 mg.

[0059] Example 7 The difference between this embodiment and embodiment 4 is that the weight of polytetrahydrofuran in this embodiment is 150 mg, and the weight of 18-crown ether-6 is 150 mg.

[0060] The supramolecular polymer semi-interpenetrating network electrolytes obtained in Examples 4 and 6-7 were tested for ionic conductivity, ion transport number, and capacity retention after 300 cycles. The results are shown in Table 4. Table 4. Performance testing of supramolecular polymer semi-interpenetrating network electrolytes in Examples 4 and 6-7. detection indicators Example 4 Example 6 Example 7 Ionic conductivity (mS / cm) 0.22 0.23 0.15 Ion transport number 0.77 0.79 0.71 Capacity retention rate after 300 cycles (%) 88.2 90.3 87.1 As shown in Examples 4, 6-7, and Table 4, the supramolecular polymer semi-interpenetrating network electrolyte of Example 6 exhibits an ionic conductivity of 0.23, an ion transport number of 0.79, and a capacity retention of 90.3% after 300 cycles, which is superior to Examples 4 and 7. Example 6 of this application uses a specific ratio of polytetrahydrofuran, dicyclohexane 4,4'-diisocyanate, and 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaborane] (i.e., a weight ratio of 1:0.27:0.18), which optimizes the balance between the rigid framework and flexible segments in the supramolecular semi-interpenetrating network structure, thereby achieving a synergistic improvement in ionic conductivity, lithium-ion transport number, mechanical strength, and cycle stability. Polytetrahydrofuran provides the flexible segments, and 18-crown ether-6 forms a pseudorotaxane with polytetrahydrofuran through hydrogen bonds, which is the basis for constructing the supramolecular network and improving ion transport number and mechanical strength. An excessively high proportion of polytetrahydrofuran and 18-crown ether-6 can lead to insufficient pseudorotaxane crosslinking points, resulting in a loose network structure and easy dendrite puncture; an excessively low proportion of polytetrahydrofuran and 18-crown ether-6 can lead to reduced ionic conductivity and interfacial instability.

[0061] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A supramolecular semi-interpenetrating polymer network electrolyte, characterized in that, The raw materials include the following parts by weight: Polytetrahydrofuran 150-300 parts, 18-crown ether-6 150-300 parts, dicyclohexane 4,4'-diisocyanate 40-60 parts, 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaboranecyclopentane] 32-48 parts, catalyst 1-1.2 parts, end-capping agent 5.5-8.5 parts, 1,3-dioxapentane 1500-2500 parts, lithium bis(trifluoromethanesulfonyl)imide 500-840 parts, scandium trifluoromethanesulfonate 23-38 parts, crosslinking agent 15-25 parts.

2. The supramolecular semi-interpenetrating polymer network electrolyte according to claim 1, characterized in that, The weight ratio of the dicyclohexane 4,4'-diisocyanate and 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaboranecyclopentane] is (5-7):

4.

3. The supramolecular semi-interpenetrating polymer network electrolyte according to claim 1, characterized in that, The weight ratio of the polytetrahydrofuran, dicyclohexane 4,4'-diisocyanate and 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaborhexacyclopentane] is 1:(0.20-0.36):(0.13-0.24).

4. The supramolecular semi-interpenetrating polymer network electrolyte according to claim 1, characterized in that, The preparation steps of the 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaborane] include: mixing 1,4-phenyldiboronic acid and 1,2,6-hexanetriol, adding a first solvent to dissolve them, then adding magnesium sulfate, stirring evenly, filtering, removing the first solvent under reduced pressure, adding n-hexane to precipitate, filtering, and obtaining 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaborane].

5. The supramolecular semi-interpenetrating polymer network electrolyte according to claim 4, characterized in that, The first solvent is tetrahydrofuran.

6. The supramolecular semi-interpenetrating polymer network electrolyte according to claim 1, characterized in that, The catalyst is dibutyltin dilaurate; the end-capping agent is 1-isocyanate-3,5-bis(trifluoromethyl)benzene; and the crosslinking agent is 2,4,6-tris(ethylene oxide-2-ylmethoxy)-1,3,5-triazine.

7. The supramolecular semi-interpenetrating polymer network electrolyte according to claim 6, characterized in that, The preparation steps of the 2,4,6-tris(ethylene oxide-2-ylmethoxy)-1,3,5-triazine include: adding a second solvent and glycidol to sodium hydride, mixing them evenly, then adding cyanuric chloride, mixing evenly, heating under reflux, cooling, filtering, separating and purifying to obtain 2,4,6-tris(ethylene oxide-2-ylmethoxy)-1,3,5-triazine.

8. A method for preparing a supramolecular semi-interpenetrating polymer network electrolyte according to any one of claims 1-7, characterized in that, Includes the following steps: S1. Preparation of pseudorotaxane: Polytetrahydrofuran and 18-crown ether-6 are mixed, heated and stirred until homogeneous to obtain pseudorotaxane; S2. Preparation of thermoplastic polyurethane elastomer-rotaxane: The pseudorotaxane was cooled for the first time, and dicyclohexane 4,4'-diisocyanate, catalyst and third solvent were added and mixed evenly. Then 2,2'-(1,4-phenyl)-bis[4-(4-hydroxybutyl)-1,3,2-dioxaborhecyclopentane] and catalyst were added and mixed evenly. 1-isocyanate-3,5-bis(trifluoromethyl)benzene was added and mixed evenly. The mixture was cooled for the second time, and the third solvent was removed by rotary evaporation. After purification, thermoplastic polyurethane elastomer-rotaxane was obtained. S3. Preparation of precursor solution: Add crosslinking agent, scandium trifluoromethanesulfonate, 1,3-dioxolane, and lithium bis(trifluoromethanesulfonyl)imide to thermoplastic polyurethane elastomer-rotaxane, mix well to obtain precursor solution; S4. Preparation of supramolecular polymer semi-interpenetrating network electrolyte: The precursor solution is polymerized in situ under argon atmosphere to obtain the supramolecular polymer semi-interpenetrating network electrolyte.

9. The use of a supramolecular semi-interpenetrating polymer network electrolyte according to any one of claims 1-7 in the preparation of lithium batteries.

10. A lithium battery, characterized in that, The positive electrode is one of lithium iron phosphate electrode sheet and lithium nickel cobalt manganese electrode sheet, the negative electrode is metallic lithium, and the electrolyte is the supramolecular semi-interpenetrating polymer network electrolyte as described in any one of claims 1-7.

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