A porous polymer electrolyte and a preparation method and application thereof

Abstract

The present application relates to a kind of porous polymer electrolyte, with polyarylether porous material of nano-pore channel structure as electrolyte main structure, lithium ion electrolyte is immersed inside nano-pore channel, the specific surface area of polyarylether porous material is 400-1000m 2 / g, pore size distribution is 0.5-10nm;The polyarylether is by the condensation of multiple hydroxyl compounds with rigid helical structure and multiple end halogen substitution group containing compounds with rigid structure, which has multiple terminal halogen substitution group.The electrolyte of the present application uses inherent microporous polymer material as the main material, forms a self-supporting film, and becomes an electrolyte after being activated by a liquid electrolyte. It is applied in the field of lithium ion batteries. The ion solvation cage formed by the inherent microporous polymer and lithium ion improves the ion transport kinetics. And multiple functional groups are introduced to improve the oxidation stability of the electrolyte and broaden the electrochemical window of the electrolyte.

Description

Technical Field

[0001] This invention relates to the field of lithium-ion battery technology, specifically to a porous polymer electrolyte, its preparation method, and its application. Background Technology

[0002] With the widespread application of lithium-ion batteries, there are increasingly higher requirements for their energy density and safety. Traditional liquid electrolytes cannot effectively suppress the growth of lithium dendrites and have disadvantages such as flammability, volatility, and leakage, making the batteries susceptible to fire and explosion. Replacing liquid electrolytes with intrinsically safe solid electrolytes can improve battery safety performance, but inorganic solid electrolytes have disadvantages such as low room temperature ionic conductivity, poor ion transport performance at the electrode-electrolyte interface, and difficulty in large-scale application.

[0003] Using quasi-solid-state electrolytes can complement the advantages of liquid and solid electrolytes, offering benefits such as high ionic conductivity at room temperature, good electrode-electrolyte interface contact, low liquid content, and good safety performance. Patent 202211286228.2 discloses a polyether-based quasi-solid-state electrolyte and its preparation method, obtaining the quasi-solid-state electrolyte through in-situ polymerization. However, polyethers have a low glass transition temperature, failing to provide a "liquid-locking" function at high temperatures. Patent 202111030918.7 proposes a 3D network quasi-solid-state electrolyte, a quasi-solid-state lithium-ion battery, and its preparation method. Cross-linked polymers improve the electrolyte's thermal stability and "liquid-locking" ability; however, the cross-linked polymer structure results in slow ion transport kinetics, leading to poor cycle and rate performance in the lithium-ion battery.

[0004] Using porous materials as electrolytes leverages their spatial confinement effect to effectively adsorb liquid components and enhance ion transport performance. Patent 202010241327.3 proposes a quasi-solid-state electrolyte based on a self-supporting membrane made of porous materials, its preparation method, and its applications. This method utilizes metal-organic framework materials as the main component of the electrolyte, improving its electrochemical performance and safety. However, the high cost of synthetic monomers and complex synthesis processes associated with metal-organic framework materials limit their large-scale application. Summary of the Invention

[0005] To address the shortcomings of existing solid-state electrolytes, such as insufficient electrochemical performance, high manufacturing costs, and complex preparation processes, this invention proposes a method for preparing and applying a porous polymer electrolyte. The electrolyte uses an inherently microporous polymer material as the main component, forming a self-supporting thin film. After activation by a liquid electrolyte, it becomes the electrolyte and is applied in the lithium-ion battery field. The "spatial confinement effect" of the porous material is utilized to alter the physicochemical properties of the electrolyte in a sub-nanometer environment. The ion solvation cage formed by the inherently microporous polymer and lithium ions enhances ion transport kinetics; furthermore, the introduction of multiple functional groups improves the electrolyte's oxidation stability and broadens its electrochemical window; and the porous structure of the inherently microporous polymer regulates the lithium-ion solvation structure, hindering anion migration and increasing the lithium-ion transference number. This invention achieves the above objectives through the following technical solutions:

[0006] A porous polymer electrolyte uses a polyarylether porous material with a nanoporous structure as the main electrolyte structure, in which lithium-ion electrolyte is immersed. The specific surface area of ​​the polyarylether porous material is 400–1000 m². 2 / g, with a pore size distribution of 0.5-10nm; the polyarylether is obtained by condensation of a polyhydroxy compound with a rigid helical structure and a compound with a rigid structure containing multiple terminal halogen substituents.

[0007] Furthermore, the electrolyte content of the porous polymer electrolyte is 2-10 wt%, preferably 5-7 wt%.

[0008] Further, the polyhydroxy compound having a rigid helical structure is selected from 5,5',6,6'-tetrahydroxy-3,3,3',3'-tetramethyl-1,1'-spirobisinden, 2,2',3,3'-tetrahydroxy-1,1'-dinaphthyl, 1,2,4,5-tetrahydroxybenzene, 9,10-dimethyl-9,10-dihydro-9,10-ethionthranil-2,3,6,7-tetraphenol, 9,9'-bis(3,4-dihydroxyphenyl)fluorene, 5,5',6,6'-tetrahydroxy The compound having a rigid structure and containing multiple terminal halogen substituents is selected from at least one of 3,3'-dicarbonyl-1,1'-spirobisinden, 1,4-bis(3,4-dihydroxybenzene)-2,3,5,6-tetraphenylbenzene, and hexaphenylphenol; the compound having a rigid structure and containing multiple terminal halogen substituents is selected from one of decafluorobiphenylone, 2,3,5,6-tetrafluoroisocyanonitrile, decafluorobiphenyl, 2,3,5,6-tetrafluoroterephthalonitrile, 2,3,5,6-tetrachloroterephthalonitrile, 2,3,5,6-tetrachloroisocyanonitrile, decachlorobiphenyl, and decachlorobiphenylone.

[0009] The lithium-ion electrolyte is composed of a lithium salt and a solvent. The lithium salt is selected from at least one of lithium bis(oxalato)borate, lithium difluorooxalato)borate, lithium bis(difluorosulfonyl)imide, lithium bis(trifluoromethyl)sulfonylimide, lithium perchlorate, lithium tetrafluoroborate, and lithium hexafluorophosphate. The solvent is an ester or an ether. The ester organic solvent includes at least one of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, and fluoroethylene carbonate. The ether organic solvent includes at least one or more of 1,3-dioxolane, ethylene glycol dimethyl ether, dimethyl ether, diethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, and tetrahydrofuran. The lithium salt electrolyte concentration in the electrolyte is 0.5-2M.

[0010] Only polyaryl ethers obtained through the condensation polymerization of monomers with the aforementioned high functionality (four or more hydroxyl / halogen atoms) and rigid structure can yield the porous polymer material with nanoscale pores required in this invention. The confinement effect of the porous material alters the physicochemical properties of the lithium-ion electrolyte. The nanopores form ion solvation cages with the solvent in the lithium-ion electrolyte, improving the coordination environment of lithium ions and enhancing ion transport kinetics. Furthermore, the size sieving effect of the porous structure can be utilized to anchor anions in lithium salts, increasing the lithium-ion transference number of the electrolyte and fully leveraging the electrochemical performance of the solid-state electrolyte.

[0011] The present invention also provides a method for preparing the porous polymer electrolyte, comprising the following steps:

[0012] (S1) A polyarylene ether porous material is obtained by condensing a polyhydroxy compound with a rigid helical structure and a compound with a rigid structure containing multiple terminal halogen substituents.

[0013] (S2) The adhesive, polyarylene ether porous material and organic solvent are prepared into a gel, which is coated on a polyester film, rolled and dried to form a self-supporting film with polyarylene ether porous material on the polyester surface.

[0014] (S3) Immerse the self-supporting membrane in an electrolyte formed by an organic solvent of lithium salt. After sufficient wetting, remove the self-supporting membrane and dry it to obtain the porous polymer electrolyte.

[0015] This invention first synthesizes inherently porous polymer material powder using a solvothermal method, then coats a gel-like slurry containing the porous polymer material powder onto a polyester film, dries it to form a self-supporting film, and finally immerses it in a lithium salt electrolyte solution and dries it to obtain a porous polymer electrolyte material with nanoscale pores.

[0016] Further, in step (S1), the molar ratio of the polyhydroxy compound with a rigid helical structure to the compound with a rigid structure containing multiple terminal halogen substituents is 1:1-1.2. The reaction solvent is selected from at least one of N,N-dimethylformamide, acetonitrile, acetone, tetrahydrofuran, chloroform, bromoethane, and cyclohexane. The amount of reaction solvent is not particularly limited, as long as it is sufficient to ensure the smooth progress of the condensation reaction. For example, the volume ratio of the reaction solvent to the total mass of the monomers is 1g:10-20mL. The condensation reaction conditions are in the presence of a base, at 60-90℃ for 60-100h, for example, at 70-80℃ for 72-96h. The base is selected from at least one of sodium carbonate, potassium carbonate, cesium carbonate, sodium ethoxide, and potassium ethoxide. The ratio of the base to the total mass of the monomers is 1.5-3:1. After the reaction is completed, the product is poured into water to obtain a precipitate of crude polymer. This precipitate is washed, dried, and a porous polymer material is obtained.

[0017] Further, in step (S2), the adhesive is at least one of polytetrafluoroethylene, polyvinylidene fluoride, polymethyl methacrylate, poly(vinylidene fluoride-co-hexafluoropropylene), polyacrylic acid, lithium carboxymethyl cellulose, sodium carboxymethyl cellulose, and styrene-butadiene latex; the organic solvent is selected from at least one of dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, sulfolane, and N-methylpyrrolidone.

[0018] Furthermore, in step (S2), the mass ratio of the polyarylene porous material to the binder is 5-10:1, such as 6:1, 7:1, 8:1, or 9:1; and the solid content in the gel is 60-80%.

[0019] Furthermore, in step (S2), the coating thickness of the gel onto the polyester film is such that the thickness of the self-supporting film obtained after drying in step (S2) is 5-200 μm, preferably 20-50 μm. A smaller film thickness can reduce the impedance of the electrolyte and lower the battery impedance.

[0020] Furthermore, in step (S2), there are no particular limitations on rolling and drying, which are well known in the art. For example, rolling is a heated rolling process, and the rolling thickness is controlled by controlling the gap between the two rollers. Drying is performed at 120-150℃ for 8-12 hours to fully remove organic solvents.

[0021] Further, in step (S3), the lithium salt is selected from at least one of lithium bis(oxalato)borate, lithium difluorooxalato)borate, lithium bis(difluorosulfonyl)imide, lithium bis(trifluoromethyl)sulfonyl)imide, lithium perchlorate, lithium tetrafluoroborate, and lithium hexafluorophosphate; the organic solvent is an ester or an ether; the ester organic solvent includes at least one of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, and fluoroethylene carbonate; the ether organic solvent includes at least one or more of 1,3-dioxolane, ethylene glycol dimethyl ether, dimethyl ether, diethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, and tetrahydrofuran. In the electrolyte, the lithium salt electrolyte concentration is 0.5-2M, for example, 1M, 1.2M, 1.5M, or 1.7M.

[0022] The present invention also provides a lithium-ion battery, including a positive electrode, a negative electrode, and the aforementioned porous polymer electrolyte disposed between the positive electrode and the negative electrode. Attached Figure Description

[0023] Figure 1 This is a TEM image of the inherent microporous polymer in Example 1.

[0024] Figure 2 This is a BET test diagram of the microporous polymer in Example 1.

[0025] Figure 3 This is a diagram showing the pore size and pore volume of the microporous polymer inherent in Example 1.

[0026] Figure 4 The 7Li nuclear magnetic resonance spectrum is that of the porous polymer electrolyte obtained in Example 1.

[0027] Figure 5 This is the electrochemical impedance spectroscopy of Example 1.

[0028] Figure 6 This is a lithium-ion transference number test graph from Example 1.

[0029] Figure 7 This is a linear scanning voltammetry test graph from Example 1.

[0030] Figure 8 This is a cycle performance diagram of the lithium metal anode / lithium cobalt oxide cathode in Example 1. Detailed Implementation

[0031] The following will further illustrate the above-described embodiments of the present invention with reference to specific examples. However, those skilled in the art will understand that the following examples are only for illustrating the present invention, and all technologies based on the above content of the present invention fall within the scope of the present invention.

[0032] The preparation process of the lithium cobalt oxide positive electrode sheet in the following embodiments is as follows: Lithium cobalt oxide powder, SuperP, and binder are weighed in a mass ratio of 8:1:1, and thoroughly ground and mixed using a mortar to obtain a uniform positive electrode slurry. The slurry is then coated onto the surface of aluminum foil using a scraper, dried in a forced-air oven at 80°C for 2 hours, and then dried in a vacuum oven at 80°C for 12 hours to fully remove the organic solvents from the electrode sheet. After drying, the mass of the active material of the electrode sheet is weighed and placed in a glove box for later use.

[0033] Electrochemical performance testing: CR2032 coin cells with standard stainless steel pads / examples / standard stainless steel pads, lithium metal anodes / examples / standard stainless steel pads, lithium metal anodes / quasi-solid electrolytes / lithium cobalt oxide cathodes were assembled according to the examples and their performance was tested using a Princeton electrochemical workstation and a LAND charge-discharge tester.

[0034] Example 1

[0035] 1.26 g of 5,5',6,6'-tetrahydroxy-3,3,3',3'-tetramethyl-1,1'-spirobisindane (A1), 0.74 g of decafluorobenzyl ketone (B1), and 4.10 g of potassium carbonate were dissolved in 25 ml of anhydrous N,N-dimethylformamide and reacted at 70 °C for 72 h. The solution was then poured into 40 ml of water to obtain an intrinsically microporous polymer precipitate. After washing three times with deionized water and ethanol, the precipitate was dried at 150 °C for 12 h to obtain an intrinsically microporous polymer powder. The intrinsically microporous polymer powder was mixed with a binder solution at a polymer-to-binder mass ratio of 9:1. The mixture was coated onto PET, rolled, and dried to a thickness of 25 μm to obtain a self-supporting film. The self-supporting film was thoroughly wetted with 1 M LiPF6 EMC / DEC electrolyte. After removing excess electrolyte from the surface, the film was vacuum dried to obtain an electrolyte membrane with a liquid content of 5 wt.%. A battery was assembled, and its electrochemical performance was tested.

[0036] Example 2

[0037] The rest is the same as in Example 1, except that the monomers selected for the synthesized intrinsically microporous polymer are 5,5',6,6'-tetrahydroxy-3,3,3',3'-tetramethyl-1,1'-spirobisindane (A1) and 2,3,5,6-tetrafluoroisocyanonitrile (B2).

[0038] Example 3

[0039] The rest is the same as in Example 1, except that the monomers selected for the synthesized intrinsically microporous polymer are 5,5',6,6'-tetrahydroxy-3,3,3',3'-tetramethyl-1,1'-spirobisindane (A1) and decafluorobiphenyl (B3).

[0040] Example 4

[0041] The rest is the same as in Example 1, except that the monomers selected for the synthesized intrinsically microporous polymer are 5,5',6,6'-tetrahydroxy-3,3,3',3'-tetramethyl-1,1'-spirobisindane (A1) and 2,3,5,6-tetrafluoroterephthalonitrile (B4).

[0042] Example 5

[0043] The rest is the same as in Example 1, except that the monomers selected for the synthesized intrinsically microporous polymer are 5,5',6,6'-tetrahydroxy-3,3,3',3'-tetramethyl-1,1'-spirobisindane (A1) and 2,3,5,6-tetrachloroterephthalonitrile (B5).

[0044] Example 6

[0045] The rest is the same as in Example 1, except that the monomers selected for the synthesized intrinsically microporous polymer are 5,5',6,6'-tetrahydroxy-3,3,3',3'-tetramethyl-1,1'-spirobisindane (A1) and 2,3,5,6-tetrachloroisocyanuric acid nitrile (B6).

[0046] Example 7

[0047] The rest is the same as in Example 1, except that the monomers selected for the synthesized intrinsically microporous polymer are 5,5',6,6'-tetrahydroxy-3,3,3',3'-tetramethyl-1,1'-spirobisindane (A1) and decachlorobiphenyl (B7).

[0048] Example 8

[0049] The rest is the same as in Example 1, except that the monomers selected for the synthesized intrinsically microporous polymer are 5,5',6,6'-tetrahydroxy-3,3,3',3'-tetramethyl-1,1'-spirobisindane (A1) and decachlorobenzyl ketone (B8).

[0050] Example 9

[0051] The rest is the same as in Example 1, except that the monomers selected for the synthesized intrinsically microporous polymer are 2,2',3,3'-tetrahydroxy-1,1'-dinaphthyl (A2) and decafluorobenzyl ketone (B1).

[0052] Example 10

[0053] The rest is the same as in Example 1, except that the monomers selected for the synthesized intrinsically microporous polymer are 1,2,4,5-tetrahydroxybenzene (A3) and decafluorobenzyl ketone (B1).

[0054] Example 11

[0055] The rest is the same as in Example 1, except that the monomers selected for the synthesized intrinsically microporous polymer are 9,10-dimethyl-9,10-dihydro-9,10-ethione-2,3,6,7-tetraphenol (A4) and decafluorobenzyl ketone (B1).

[0056] Example 12

[0057] The rest is the same as in Example 1, except that the monomers selected for the synthesized intrinsically microporous polymer are 9,9'-bis(3,4-dihydroxyphenyl)fluorene (A5) and decafluorobenzyl ketone (B1).

[0058] Example 13

[0059] The rest is the same as in Example 1, except that the monomers selected for the synthesized intrinsically microporous polymer are 5,5',6,6'-tetrahydroxy-3,3'-dicarbonyl-1,1'-spirobisindane (A6) and decafluorobenzyl ketone (B1).

[0060] Example 14

[0061] The rest is the same as in Example 1, except that the monomers selected for the synthesized intrinsically microporous polymer are 1,4-bis(3,4-dihydroxybenzene)-2,3,5,6-tetraphenylbenzene (A7) and decafluorobenzone (B1).

[0062] Example 15

[0063] The rest is the same as in Example 1, except that the monomers selected for the synthesized intrinsically microporous polymer are hexaphenol (A8) and decafluorobenzyl ketone (B1).

[0064] Experimental results

[0065] Figure 1 The image shown is a TEM image of the inherently microporous polymer in Example 1. It can be seen that the inherently microporous polymer exhibits an amorphous shape and does not show obvious aggregation. Figure 2 This is the BET test chart of the inherently microporous polymer in Example 1, with a specific surface area of ​​634 m². 2 / g. Figure 3 The image shows the pore size and pore volume of the microporous polymer inherent in Example 1. It can be seen that the pore size distribution is about 0.7 nm, exhibiting a sub-nanometer pore size distribution. Figure 4 The 7Li NMR spectrum is that of the porous polymer electrolyte obtained in Example 1. It can be seen that the coordination environment of lithium ions in the electrolyte has changed, which is conducive to promoting lithium ion transport.

[0066] Assemble a standard stainless steel gasket / / For a CR2032 button cell with a standard stainless steel gasket, calculate the ionic conductivity of the electrolyte by AC impedance spectroscopy. Figure 5This is the electrochemical impedance spectroscopy (EIS) of Example 1. The calculated ionic conductivity is 1.1 × 10⁻⁶. -3 The S / cm ratio demonstrates the excellent ion transport kinetics of porous polymer electrolytes at room temperature, which is beneficial for improving the rate performance of batteries. Figure 6 The lithium-ion transference number (LTN) test for Example 1 is shown. The LTN reflects the proportion of lithium ions in the overall ion transport during carrier transport in the electrolyte. The LTN for Example 1 is 0.85.

[0067] The electrochemical window of the electrolyte was obtained by assembling a CR2032 coin cell with a lithium metal anode and a standard stainless steel gasket, and then testing it using a linear sweep voltammetry method. Figure 7 This is a linear sweep voltammetry chromatogram from Example 1, with an electrochemical window of 5.1 V. It demonstrates the excellent oxidative stability of the porous polymer electrolyte, which is beneficial for matching high-voltage cathode materials and improving the battery's energy density.

[0068] Assemble a CR2032 coin cell with a lithium metal anode and a lithium cobalt oxide cathode, and conduct battery cycle performance tests. Figure 8 This is a cycling performance diagram of the lithium metal anode / lithium cobalt oxide cathode in Example 1. The lithium-ion battery based on the porous polymer electrolyte exhibits excellent cycling performance, achieving stable cycling for over 300 cycles at room temperature with a capacity retention of 91.5%. Table 1 summarizes the electrochemical performance of Examples 1-15, demonstrating the excellent application prospects of the electrolyte. The synergistic effect of the fluorinated monomer decafluorobenzyl ketone used in Example 1, the inert fluorine substituent, and the active carbonyl group, along with the specific pore size and structure between the monomer 5,5',6,6'-tetrahydroxy-3,3,3',3'-tetramethyl-1,1'-helical bis-indene and decafluorobenzyl ketone, creates a coordination environment for lithium ions resembling a "locally high-concentration salt." This achieves a stable electrolyte-electrode interface, promotes carrier transport at the electrolyte-electrode interface, and thus comprehensively improves battery performance.

[0069] Table 1 Electrochemical performance of electrolyte

[0070]

[0071]

Claims

1. A porous polymer electrolyte, characterized in that, Using polyaryl ether porous materials with nanopore structures as the main electrolyte structure, lithium-ion electrolyte is immersed inside the nanopores. The specific surface area of ​​the polyaryl ether porous materials is 400~1000 m². 2 / g, with a pore size distribution of 0.5-10nm; the polyarylene ether is obtained by condensation of a polyhydroxy compound with a rigid helical structure and a compound with a rigid structure containing multiple terminal halogen substituents; The polyhydroxy compound with a rigid helical structure is selected from 5,5',6,6'-tetrahydroxy-3,3,3',3'-tetramethyl-1,1'-spirobisindane, 2,2',3,3'-tetrahydroxy-1,1'-dinaphthyl, 1,2,4,5-tetrahydroxybenzene, 9,10-dimethyl-9,10-dihydro-9,10-ethione-2,3,6,7-tetraphenol, 9,9'-bis(3,4-dihydroxyphenyl)fluorene, 5,5',6,6'-tetrahydroxy-3 The compound having a rigid structure and containing multiple terminal halogen substituents is selected from at least one of 3'-dicarbonyl-1,1'-spirobisindane, 1,4-bis(3,4-dihydroxybenzene)-2,3,5,6-tetraphenylbenzene, and hexaphenylphenol; the compound having a rigid structure and containing multiple terminal halogen substituents is selected from one of decafluorobiphenylone, 2,3,5,6-tetrafluoroisocyanonitrile, decafluorobiphenyl, 2,3,5,6-tetrafluoroterephthalonitrile, 2,3,5,6-tetrachloroterephthalonitrile, 2,3,5,6-tetrachloroisocyanonitrile, decachlorobiphenyl, and decachlorobiphenylone.

2. The porous polymer electrolyte according to claim 1, characterized in that, The electrolyte content of the porous polymer electrolyte is 2-10 wt%.

3. The porous polymer electrolyte according to claim 1, characterized in that, The electrolyte content of the porous polymer electrolyte is 5-7 wt%.

4. The porous polymer electrolyte according to claim 1, characterized in that, The lithium-ion electrolyte is composed of a lithium salt and a solvent. The lithium salt is selected from at least one of lithium bis(oxalato)borate, lithium difluorooxalato)borate, lithium bis(difluorosulfonyl)imide, lithium bis(trifluoromethyl)sulfonyl)imide, lithium perchlorate, lithium tetrafluoroborate, and lithium hexafluorophosphate. The solvent is an ester or an ether. The ester organic solvent includes at least one of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, and fluoroethylene carbonate. The ether organic solvent includes at least one or more of 1,3-dioxolane, ethylene glycol dimethyl ether, dimethyl ether, diethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, and tetrahydrofuran. The lithium salt electrolyte concentration in the electrolyte is 0.5-2 M.

5. The method for preparing the porous polymer electrolyte according to any one of claims 1-4, characterized in that, Includes the following steps: (S1) A polyarylene ether porous material is obtained by condensing a polyhydroxy compound with a rigid helical structure and a compound with a rigid structure containing multiple terminal halogen substituents. (S2) The adhesive, polyarylene ether porous material and organic solvent are prepared into a gel, which is coated on a polyester film, rolled and dried to form a self-supporting film with polyarylene ether porous material on the polyester surface. (S3) Immerse the self-supporting membrane in an electrolyte formed by an organic solvent of lithium salt. After sufficient wetting, remove the self-supporting membrane and dry it to obtain the porous polymer electrolyte.

6. The preparation method according to claim 5, characterized in that, In step (S1), the molar ratio of the polyhydroxy compound with a rigid helical structure to the compound with a rigid structure containing multiple terminal halogen substituents is 1:1-1.

2.

7. The preparation method according to claim 5, characterized in that, In step (S1), the reaction solvent is selected from at least one of N,N-dimethylformamide, acetonitrile, acetone, tetrahydrofuran, chloroform, bromoethane, and cyclohexane; the condensation reaction conditions are in the presence of a base, at 60-90℃ for 60-100 h, wherein the base is selected from at least one of sodium carbonate, potassium carbonate, cesium carbonate, sodium ethoxide, and potassium ethoxide, and the ratio of the amount of base to the total mass of monomers is 1.5-3:1; after the reaction is completed, the product is poured into water to obtain a precipitate of crude polymer, which is then washed, dried, and a porous polymer material is obtained.

8. The preparation method according to claim 7, characterized in that, In step (S1), the condensation reaction is carried out in the presence of a base at 70-80°C for 72-96 hours.

9. The preparation method according to claim 5, characterized in that, In step (S2), the adhesive is at least one of polytetrafluoroethylene, polyvinylidene fluoride, polymethyl methacrylate, poly(vinylidene fluoride-co-hexafluoropropylene), polyacrylic acid, lithium carboxymethyl cellulose, sodium carboxymethyl cellulose, and styrene-butadiene latex; the organic solvent is selected from at least one of dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, sulfolane, and N-methylpyrrolidone.

10. The preparation method according to claim 5, characterized in that, In step (S2), the mass ratio of polyarylene porous material to binder is 5-10:1; the solid content in the gel is 60-80%; the coating thickness of the gel on the polyester film is such that the thickness of the self-supporting film obtained after drying in step (S2) is 5-200 μm.

11. The preparation method according to claim 5, characterized in that, In step (S2), the coating thickness of the gel onto the polyester film is such that the thickness of the self-supporting film obtained after drying in step (S2) is 20-50 μm.

12. A lithium-ion battery, comprising a positive electrode, a negative electrode, and a porous polymer electrolyte as described in any one of claims 1-4 disposed between the positive and negative electrode.

Images