A polymer solid electrolyte membrane and a method for preparing the same

Abstract

This invention discloses a polymer solid electrolyte membrane and its preparation method. The polymer solid electrolyte membrane is prepared by melt polycondensation and lithiation of C4–C10 aliphatic dicarboxylic acids, C8–C20 aromatic dicarboxylic acids or their esters, sulfonated monomers and C2–C10 aliphatic diols as raw materials to obtain an aromatic copolymer modified ionomer skeleton. The aromatic segments significantly improve the melting point and high-temperature dimensional properties of the solid electrolyte membrane, enabling spontaneous functional separation of crystalline and amorphous regions at the microscale. This overcomes the dependence of ion transport on polymer chain segment oscillation and achieves simultaneous improvement of the ionic conductivity, mechanical strength and heat resistance of the polymer electrolyte membrane.

Description

Technical Field

[0001] This invention belongs to the field of all-solid-state electrolyte technology, specifically, it relates to a polymer solid electrolyte membrane and its preparation method. Background Technology

[0002] Solid polymer electrolytes (SPEs) are considered key materials for overcoming the safety bottleneck of lithium metal batteries and achieving high energy density due to their excellent flexibility, processability, and interfacial compatibility. Currently, polyethylene oxide (PEO)-based electrolytes are the most widely studied SPE systems. Their ether-oxygen groups can effectively dissolve lithium salts and exhibit certain ion conductivity above the glass transition temperature (Tg).

[0003] However, the ion conduction mechanism of PEO-based electrolytes is highly dependent on the movement of amorphous polymer chain segments. This dependence leads to two inherent contradictions: first, PEO is semi-crystalline at room temperature, with weak chain segment mobility, resulting in low ionic conductivity (typically only a few times higher). Secondly, there is a trade-off between ion conductivity and mechanical strength; improving chain segment mobility can enhance ion conductivity, but inevitably sacrifices the electrolyte's mechanical strength and dimensional stability. At high temperatures (above 60°C), PEO is in a near-molten state. Although conductivity increases, mechanical properties deteriorate sharply, making it difficult to effectively suppress lithium dendrite growth. Furthermore, PEO has poor oxidative stability, making it difficult to match with high-voltage cathode materials. Therefore, overcoming this trade-off between ion conductivity and mechanical / thermal stability is a core scientific challenge in the field of polymer solid electrolytes.

[0004] While existing technologies have overcome the aforementioned problems to some extent by adding plasticizers or inorganic fillers and designing block copolymers, the addition of plasticizers significantly reduces the mechanical strength of the electrolyte and increases the risk of interfacial side reactions. Inorganic nanofillers can inhibit PEO crystallization through Lewis acid-base interactions, improving mechanical properties and interfacial stability, but the fillers are prone to agglomeration and have poor interfacial compatibility, making it difficult to achieve uniform dispersion while ensuring conductivity. For block copolymerization schemes, the rigid phase itself is electrochemically inert and does not participate in ion conduction, resulting in interfacial impedance between the two phases. Ion conduction relies entirely on the flexible phase, and the lithium-ion transference number remains limited. These problems all restrict the development of polymer solid electrolyte technology.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] To address the aforementioned technical problems, the first aspect of this invention provides a polymer solid electrolyte membrane, comprising an aromatic copolymer-modified ionomer framework prepared by melt polycondensation and lithiation of C4–C10 aliphatic diacids, C8–C20 aromatic diacids or their esters, sulfonated monomers, and C2–C10 aliphatic diols as raw materials. The introduction of aromatic segments significantly improves the melting point and high-temperature dimensional stability of the ionomer framework, enabling spontaneous functional separation of the crystalline and amorphous regions at the microscale. The crystalline region provides mechanical support and a heat-resistant framework, while the three-dimensional interconnected ion cluster network formed by the aggregation of lithium sulfonate groups in the amorphous region provides a rapid lithium-ion transport channel. This overcomes the dependence of ion transport on chain segment oscillation, achieving a simultaneous improvement in ionic conductivity, mechanical strength, and heat resistance.

[0007] The second aspect of this invention provides a method for preparing the aforementioned polymer electrolyte membrane. This method employs a three-step process: melt polycondensation, mild lithiation, and controlled film formation. By selecting appropriate processes, the weight-average molecular weight of the ionomer backbone and the crystallinity of the polymer solid electrolyte membrane are adjusted, resulting in the in-situ construction of a uniform crystalline fiber network and ion cluster distribution. This method features mild process conditions and simple steps, requiring no external fillers or a second conductive phase, and yields a polymer solid electrolyte membrane exhibiting high heat resistance, high ionic conductivity, high lithium-ion transference number, and high mechanical strength.

[0008] To achieve the above objectives, a first aspect of the present invention provides a polymer solid electrolyte membrane comprising an ionomer framework and a lithium salt, wherein the ionomer framework is prepared by melt polycondensation and lithiation of a C4-C10 aliphatic diacid, a C8-C20 aromatic diacid or its ester, a sulfonated monomer, and a C2-C10 aliphatic diol; wherein the sulfonated monomer is an aromatic or aliphatic diacid or its ester derivative containing at least one sulfonic acid group.

[0009] Further, the C2-C10 aliphatic dicarboxylic acid is selected from at least one of succinic acid, glutaric acid, adipic acid, pimelic acid, and octanoic acid; the C8-C20 aromatic dicarboxylic acid is selected from at least one of terephthalic acid, dimethyl terephthalate, isophthalic acid, dimethyl isophthalate, phthalic acid, phthalic anhydride, 2,6-naphthalenedicarboxylic acid, and dimethyl 2,6-naphthalenedicarboxylic acid; the sulfonated monomer is selected from at least one of sodium isophthalate-5-sulfonate, sodium 1,2-(dimethoxycarbonyl)ethanesulfonate, sulfosuccinic acid, 4-sulfophthalic acid, and sulfonaphthalenedicarboxylic acid; the aliphatic diol is selected from at least one of ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentanediol, diethylene glycol, and 1,4-cyclohexanediethanol.

[0010] Further, the C2-C10 aliphatic dicarboxylic acid is at least one of succinic acid and adipic acid; the C8-C20 aromatic dicarboxylic acid is selected from at least one of terephthalic acid, dimethyl terephthalate, isophthalic acid, and dimethyl isophthalate; the sulfonated monomer is selected from at least one of sodium isophthalate-5-sulfonate, sodium 1,2-(dimethoxycarbonyl)ethanesulfonate, and sulfosuccinic acid; the C2-C10 aliphatic diol is selected from at least one of 1,4-butanediol, 1,6-hexanediol, diethylene glycol, and 1,4-cyclohexanediethanol.

[0011] Furthermore, the mass percentage of the raw materials used to prepare the ionomer framework is as follows: C4-C10 aliphatic dicarboxylic acids: 25%-60% C8-C20 aromatic dicarboxylic acids or their esters: 5%-30% Sulfonated monomers: 5%-25% C2-C10 aliphatic diols: 15%-45% Furthermore, the molar ratio of carboxyl groups in all dicarboxylic acid monomers to hydroxyl groups in all diol monomers is in the range of 1:(1-1.3).

[0012] Preferably, the mass ratio of the raw materials used to prepare the ionomer framework is: C4-C10 aliphatic dicarboxylic acids: 35%-55% C8-C20 aromatic dicarboxylic acids or their esters: 10%-25% Sulfonated monomers: 10%-20% C2-C10 aliphatic diols: 20%-45%.

[0013] Furthermore, the lithium salt is selected from at least one of lithium tetrafluoroborate, lithium bis(trifluoromethanesulfonyl)imide, lithium difluorooxalate borate, lithium bis(fluorosulfonyl)imide, and lithium bis(oxalate borate).

[0014] Furthermore, the weight-average molecular weight of the ionomer backbone ranges from 30,000 to 100,000 g / mol, and the crystallinity ranges from 18% to 45%; preferably, the crystallinity ranges from 20% to 45%.

[0015] A more preferred crystallinity range is 25%-40%.

[0016] A second aspect of the present invention provides a method for preparing the above-mentioned polymer solid electrolyte membrane, comprising the following steps: S1. Preparation of ionomer framework intermediates via melt polycondensation; S2. The ionomer backbone intermediate is lithiated to obtain the ionomer backbone. S3. The ionomer framework treated in step S2 is mixed with lithium salt to form a film.

[0017] Further, step S1 specifically involves: weighing C4-C10 aliphatic dicarboxylic acids, C8-C20 aromatic dicarboxylic acids or their esters, sulfonated monomers and C2-C10 aliphatic diols, mixing them together, adding a catalyst, and esterifying them at 160℃-190℃ under a protective atmosphere until the acid value of the reactants reaches or is less than the preset acid value threshold. Then, the temperature is raised to 200℃-245℃, and polycondensation is carried out under vacuum to obtain an ionomer skeleton intermediate.

[0018] Further, in step S1, the preset acid value threshold is 20 mg KOH / g; the polycondensation reaction is stopped when the weight-average molecular weight of the product reaches 30,000–100,000 g / mol, and an ionomer skeleton intermediate is obtained.

[0019] Further, step S2 specifically involves immersing the ionomer framework intermediate obtained in step S1 in an alkaline solution containing lithium ions for ion exchange, followed by filtration, washing, and vacuum drying to obtain the ionomer framework.

[0020] Furthermore, the alkaline solution containing lithium ions is an alcohol / water mixture of at least one of lithium hydroxide and lithium carbonate, and the ion exchange process is: continuous stirring at 25℃-40℃ for 6-18 hours.

[0021] Further, step S3 specifically involves: preparing the ionomer framework obtained in step S2 into a solution, adding lithium salt to the solution, mixing and pouring the mixture into a mold, controlling the solvent evaporation rate at 0.5-3 μm / min for 6-18 hours at a temperature of 40℃-60℃ and a relative humidity of less than 30%, and then vacuum drying to obtain a polymer solid electrolyte membrane; wherein the mass ratio of the ionomer framework to the lithium salt is 1:(0.08-0.14).

[0022] Furthermore, the solvent for the ionomer skeleton is a fluoroalcohol solvent; preferably hexafluoroisopropanol.

[0023] Alternatively, as an alternative to the above scheme, step S3 specifically involves uniformly mixing the ionomer framework obtained in step S2 with lithium salt, and then hot-pressing it for 5-15 minutes at a temperature of 120℃-180℃ and a pressure of 5-15MPa to obtain a polymer solid electrolyte membrane.

[0024] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art.

[0025] 1. This invention constructs a semi-crystalline ionomer framework that combines flexibility and rigidity through the synergistic copolymerization of C4–C10 aliphatic diacarboxylic acids and C8–C20 aromatic diacarboxylic acids. The crystalline region provides mechanical support as a physical crosslinking point, while the amorphous region provides ion transport channels through an ion cluster network. Furthermore, the electrostatic crosslinking between lithium sulfonate groups further enhances the network structure. The strength of the ionomer framework is significantly improved through precise control of the mass ratio of the four monomers, ensuring both high ionic conductivity and excellent mechanical properties.

[0026] 2. This invention introduces a rigid benzene ring structure into the ionomer backbone, significantly increasing the melting point and heat distortion temperature of the crystalline region, effectively solving the technical defects of existing polyester ionomers such as poor heat resistance and loss of mechanical support due to high-temperature softening. Simultaneously, through the introduction of sulfonated monomers, a three-dimensional interconnected ion cluster network of spontaneously aggregated lithium sulfonate groups is formed in the amorphous region of the ionomer backbone. This ion cluster network provides a low-barrier structural hopping transport channel for lithium ions, freeing ion conduction from its sole dependence on polymer chain segment movement.

[0027] 3. In this invention, the sulfonate groups in the sulfonated monomer are converted into lithium sulfonate after lithiation treatment and are covalently fixed to the main chain of the ionomer backbone. This structure prevents the anions of the added lithium salt from migrating freely due to electrostatic repulsion caused by the fixed negative charge, allowing lithium ions to hop and transport within the ion cluster network, thus significantly increasing the lithium ion transference number. This characteristic eliminates the risks of concentration polarization and lithium dendrite growth caused by anion migration in traditional dual-ion conductors, significantly improving the cycle stability and safety of the battery.

[0028] 4. This invention employs a three-step process of melt polycondensation, mild lithiation, and controllable film formation. By controlling the parameters in each process, the microstructure of the polymer electrolyte membrane can be precisely controlled within the range of 18%–45%, ensuring the mechanical support of the crystalline framework while leaving sufficient space for ion conduction in the amorphous region. Furthermore, this process does not require the addition of external fillers or a second conductive phase, has simple steps, and controllable parameters, making it a promising candidate for industrial application. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0030] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. Example 1

[0031] S1. Preparation of ionomer framework intermediates via melt polycondensation 64.9g of succinic acid, 21.9g of adipic acid, 24.9g of terephthalic acid, 8.3g of isophthalic acid, 29.6g of sodium isophthalate-5-sulfonate, and 99.1g of 1,4-butanediol were weighed and added to a reactor. Then, 0.62g of tetrabutyl titanate catalyst and 0.12g of triphenyl phosphite heat stabilizer were added. Under nitrogen protection, the mixture was heated to 175℃ and subjected to esterification at atmospheric pressure for 3 hours. Water, a byproduct, was collected during the reaction using a water separator. Esterification ended when the acid value dropped below 20mgKOH / g. The reaction system was then slowly heated to 225℃ and gradually evacuated to below 100Pa. Polycondensation was carried out for 4 hours until the weight-average molecular weight reached 60,000g / mol, at which point the reaction was stopped. Nitrogen was introduced to restore atmospheric pressure, the mixture was discharged, cooled, and pelletized to obtain an ionomer backbone intermediate.

[0032] S2. Lithylating the ionomer backbone intermediate to obtain the ionomer backbone. The ionomer backbone intermediate obtained in step S1 was immersed in a methanol / water mixed solution (volume ratio 2:1) with a lithium hydroxide concentration of 1 mol / L and stirred at 30°C for 12 hours for ion exchange. The product was then filtered, washed three times with anhydrous methanol, and dried in a vacuum oven at 70°C for 18 hours to obtain the ionomer backbone.

[0033] S3. The ionomer framework treated in step S2 is mixed with lithium salt to form a film. The ionomer backbone obtained in step S2 was dissolved in hexafluoroisopropanol to prepare a solution with a solid content of 15 wt%. A lithium salt comprising lithium bis(trifluoromethanesulfonyl)imide and lithium difluorooxalateborate in a mass ratio of 3:1 was added, and the mixture was stirred at room temperature for 3 hours until homogeneous. The solution was coated onto a polytetrafluoroethylene mold, and the solvent evaporation rate was controlled at 1.5 μm / min for 10 hours at 50°C and 20% relative humidity. Subsequently, the mixture was placed in a vacuum oven and dried at 70°C for 18 hours to obtain a polymer solid electrolyte membrane with a thickness of 40 μm.

[0034] Based on Example 1, the following examples were obtained by adjusting the type of raw materials. Example 2

[0035] S1. Preparation of ionomer framework intermediates via melt polycondensation 64.9g of succinic acid, 21.9g of adipic acid, 24.9g of terephthalic acid, 10.8g of 2,6-naphthalenedicarboxylic acid, 29.6g of sodium isophthalic acid-5-sulfonate, and 99.1g of 1,4-butanediol were weighed and added to a reactor. Then, 0.63g of tetrabutyl titanate catalyst and 0.13g of triphenyl phosphite heat stabilizer were added. Under nitrogen protection, the mixture was heated to 180℃ and subjected to esterification at atmospheric pressure for 3.5 hours. Water, a byproduct, was collected during the reaction using a water separator. Esterification ended when the acid value dropped below 20mgKOH / g. The reaction system was then slowly heated to 230℃ and gradually evacuated to below 100Pa. Polycondensation was carried out for 4.5 hours until the weight-average molecular weight reached 55000g / mol. Nitrogen was introduced to restore atmospheric pressure, the mixture was discharged, cooled, and pelletized to obtain an ionomer backbone intermediate.

[0036] S2. Lithylating the ionomer backbone intermediate to obtain the ionomer backbone. The ionomer backbone intermediate obtained in step S1 was immersed in a methanol / water mixed solution (volume ratio 2:1) with a lithium hydroxide concentration of 1 mol / L and stirred at 30°C for 12 hours for ion exchange. The product was then filtered, washed three times with anhydrous methanol, and dried in a vacuum oven at 70°C for 18 hours to obtain the ionomer backbone.

[0037] S3. The ionomer framework treated in step S2 is mixed with lithium salt to form a film. The ionomer backbone obtained in step S2 was dissolved in hexafluoroisopropanol to prepare a solution with a solid content of 12 wt%. A lithium salt comprising lithium bis(trifluoromethanesulfonyl)imide and lithium difluorooxalateborate in a mass ratio of 3:1 was added, and the mixture was stirred at room temperature for 3 hours until homogeneous. The solution was coated onto a polytetrafluoroethylene mold, and the solvent evaporation rate was controlled at 1.0 μm / min for 12 hours at 50°C and 20% relative humidity. Subsequently, the mixture was placed in a vacuum oven and dried at 70°C for 18 hours to obtain a polymer solid electrolyte membrane with a thickness of 45 μm. Example 3

[0038] S1. Preparation of ionomer framework intermediates via melt polycondensation 59.0 g of succinic acid, 36.5 g of adipic acid, 16.6 g of isophthalic acid, 40.2 g of sodium 1,2-(dimethoxycarbonyl)ethanesulfonate (SDMF), 74.3 g of 1,4-butanediol, and 31.8 g of diethylene glycol were weighed and added to a reactor. Then, 0.65 g of tetrabutyl titanate catalyst and 0.13 g of triphenyl phosphite heat stabilizer were added. Under nitrogen protection, the mixture was heated to 170 °C and subjected to esterification at atmospheric pressure for 3 hours. Water, a byproduct, was collected during the reaction using a water separator. Esterification ended when the acid value dropped below 20 mg KOH / g. The reaction system was then slowly heated to 215 °C and gradually evacuated to below 100 Pa. Polycondensation was carried out for 3.5 hours until the weight-average molecular weight reached 50,000 g / mol. Nitrogen gas was introduced to restore atmospheric pressure, the mixture was discharged, cooled, and pelletized to obtain an ionomer backbone intermediate.

[0039] S2. Lithylating the ionomer backbone intermediate to obtain the ionomer backbone. The ionomer backbone intermediate obtained in step S1 was immersed in a methanol / water mixed solution (volume ratio 2:1) with a lithium hydroxide concentration of 1 mol / L and stirred at 30°C for 10 hours for ion exchange. The product was then filtered, washed three times with anhydrous methanol, and dried in a vacuum oven at 70°C for 16 hours to obtain the ionomer backbone.

[0040] S3. The ionomer framework treated in step S2 is mixed with lithium salt to form a film. The ionomer backbone obtained in step S2 was dissolved in hexafluoroisopropanol to prepare a solution with a solid content of 18 wt%. A lithium salt comprising lithium bis(trifluoromethanesulfonyl)imide and lithium bis(fluorosulfonyl)imide in a mass ratio of 2:1 was added, and the mixture was stirred at room temperature for 3 hours until homogeneous. The solution was coated onto a polytetrafluoroethylene mold, and the solvent evaporation rate was controlled at 2.0 μm / min for 8 hours at 45°C and 25% relative humidity. Subsequently, the mixture was placed in a vacuum oven and dried at 65°C for 16 hours to obtain a polymer solid electrolyte membrane with a thickness of 35 μm. Example 4

[0041] S1. Preparation of ionomer framework intermediates via melt polycondensation 82.6 g of succinic acid, 33.2 g of terephthalic acid, 19.8 g of sulfosuccinic acid, 72.1 g of 1,4-butanediol, and 23.6 g of 1,6-hexanediol were weighed and added to a reactor. Then, 0.58 g of tetrabutyl titanate catalyst and 0.12 g of triphenyl phosphite heat stabilizer were added. Under nitrogen protection, the mixture was heated to 175°C and subjected to esterification at atmospheric pressure for 3 hours. Water, a byproduct, was collected during the reaction using a water separator. Esterification ended when the acid value dropped below 20 mg KOH / g. The reaction system was then slowly heated to 225°C and gradually evacuated to below 100 Pa. Polycondensation was carried out for 4 hours until the weight-average molecular weight reached 65,000 g / mol, at which point the reaction was stopped. Nitrogen was introduced to restore atmospheric pressure, the mixture was discharged, cooled, and pelletized to obtain an ionomer backbone intermediate.

[0042] S2. Lithylating the ionomer backbone intermediate to obtain the ionomer backbone. The ionomer backbone intermediate obtained in step S1 was immersed in a methanol / water mixed solution (volume ratio 2:1) with a lithium hydroxide concentration of 1 mol / L and stirred at 30°C for 12 hours for ion exchange. The product was then filtered, washed three times with anhydrous methanol, and dried in a vacuum oven at 70°C for 18 hours to obtain the ionomer backbone.

[0043] S3. The ionomer framework treated in step S2 is mixed with lithium salt to form a film. The ionomer backbone obtained in step S2 was dissolved in hexafluoroisopropanol to prepare a solution with a solid content of 15 wt%. 8 wt% of a lithium salt, comprising lithium bis(trifluoromethanesulfonyl)imide and lithium bis(oxalatoborate) in a mass ratio of 4:1, was added, and the mixture was stirred at room temperature for 3 hours until homogeneous. The solution was coated onto a polytetrafluoroethylene mold, and the solvent evaporation rate was controlled at 1.0 μm / min for 12 hours at 50°C and 20% relative humidity. Subsequently, the mixture was placed in a vacuum oven and dried at 70°C for 18 hours to obtain a polymer solid electrolyte membrane with a thickness of 40 μm. Example 5

[0044] S1. Preparation of ionomer framework intermediates via melt polycondensation 64.9g of succinic acid, 21.9g of adipic acid, 24.9g of terephthalic acid, 8.3g of isophthalic acid, 29.6g of sodium isophthalate-5-sulfonate, 79.3g of 1,4-butanediol, and 26.0g of 1,6-hexanediol were weighed and added to a reactor. Then, 0.64g of tetrabutyl titanate catalyst and 0.13g of triphenyl phosphite heat stabilizer were added. Under nitrogen protection, the mixture was heated to 170℃ and subjected to esterification at atmospheric pressure for 3 hours. Water, a byproduct, was collected during the reaction using a water separator. Esterification ended when the acid value dropped below 20mgKOH / g. The reaction system was then slowly heated to 220℃ and gradually evacuated to below 100Pa. Polycondensation was carried out for 3.5 hours until the weight-average molecular weight reached 55000g / mol. Nitrogen was introduced to restore atmospheric pressure, the mixture was discharged, cooled, and pelletized to obtain an ionomer backbone intermediate.

[0045] S2. Lithylating the ionomer backbone intermediate to obtain the ionomer backbone. The ionomer backbone intermediate obtained in step S1 was immersed in a methanol / water mixed solution (volume ratio 2:1) with a lithium hydroxide concentration of 1 mol / L and stirred at 30°C for 12 hours for ion exchange. The product was then filtered, washed three times with anhydrous methanol, and dried in a vacuum oven at 70°C for 18 hours to obtain the ionomer backbone.

[0046] S3. The ionomer framework treated in step S2 is mixed with lithium salt to form a film. The ionomer backbone obtained in step S2 was dissolved in hexafluoroisopropanol to prepare a solution with a solid content of 16 wt%. A lithium salt comprising lithium bis(trifluoromethanesulfonyl)imide and lithium difluorooxalateborate in a mass ratio of 3:1 was added, and the mixture was stirred at room temperature for 3 hours until homogeneous. The solution was coated onto a polytetrafluoroethylene mold, and the solvent evaporation rate was controlled at 2.0 μm / min for 9 hours at 45°C and 25% relative humidity. Subsequently, the mixture was placed in a vacuum oven and dried at 65°C for 16 hours to obtain a polymer solid electrolyte membrane with a thickness of 38 μm. Example 6

[0047] S1. Preparation of ionomer framework intermediates via melt polycondensation 64.9g of succinic acid, 21.9g of adipic acid, 24.9g of terephthalic acid, 8.3g of isophthalic acid, 29.6g of sodium isophthalate-5-sulfonate, 79.3g of 1,4-butanediol, and 31.7g of 1,4-cyclohexanediol were weighed and added to a reaction vessel. Then, 0.65g of tetrabutyl titanate catalyst and 0.13g of triphenyl phosphite heat stabilizer were added to the reaction vessel. Under nitrogen protection, the temperature was raised to 175℃ and the esterification reaction was carried out at normal pressure for 3.5 hours. During the reaction, water by-products were collected through a water separator. Esterification was stopped when the acid value dropped below 20mgKOH / g. Subsequently, the reaction system was slowly heated to 230℃ and gradually evacuated to below 100Pa. Polycondensation reaction was carried out for 4.5 hours until the weight-average molecular weight reached 58000g / mol. Nitrogen gas is introduced to restore normal pressure, the material is discharged, cooled and pelletized to obtain an ionomer skeleton intermediate.

[0048] S2. Lithylating the ionomer backbone intermediate to obtain the ionomer backbone. The ionomer backbone intermediate obtained in step S1 was immersed in a methanol / water mixed solution (volume ratio 2:1) with a lithium hydroxide concentration of 1 mol / L and stirred at 30°C for 12 hours for ion exchange. The product was then filtered, washed three times with anhydrous methanol, and dried in a vacuum oven at 70°C for 18 hours to obtain the ionomer backbone.

[0049] S3. The ionomer framework treated in step S2 is mixed with lithium salt to form a film. The ionomer backbone obtained in step S2 was dissolved in hexafluoroisopropanol to prepare a solution with a solid content of 14 wt%. A lithium salt comprising lithium bis(trifluoromethanesulfonyl)imide and lithium difluorooxalateborate in a mass ratio of 3:1 was added, and the mixture was stirred at room temperature for 3 hours until homogeneous. The solution was coated onto a polytetrafluoroethylene mold, and the solvent evaporation rate was controlled at 1.0 μm / min for 12 hours at 50°C and 20% relative humidity. Subsequently, the mixture was placed in a vacuum oven and dried at 70°C for 18 hours to obtain a polymer solid electrolyte membrane with a thickness of 42 μm. Example 7

[0050] S1. Preparation of ionomer framework intermediates via melt polycondensation 76.7g of succinic acid, 11.8g of adipic acid, 33.2g of terephthalic acid, 29.6g of sodium isophthalic acid-5-sulfonate, and 99.1g of 1,4-butanediol were weighed and added to a reactor. Then, 0.62g of tetrabutyl titanate catalyst and 0.12g of triphenyl phosphite heat stabilizer were added. Under nitrogen protection, the mixture was heated to 175℃ and subjected to esterification at atmospheric pressure for 3 hours. Water, a byproduct, was collected during the reaction using a water separator. Esterification ended when the acid value dropped below 20mgKOH / g. The reaction system was then slowly heated to 225℃ and gradually evacuated to below 100Pa. Polycondensation was carried out for 4 hours until the weight-average molecular weight reached 65000g / mol. Nitrogen gas was introduced to restore atmospheric pressure, the mixture was discharged, cooled, and pelletized to obtain an ionomer backbone intermediate.

[0051] S2. Lithylating the ionomer backbone intermediate to obtain the ionomer backbone. The ionomer backbone intermediate obtained in step S1 was immersed in a methanol / water mixed solution (volume ratio 2:1) with a lithium hydroxide concentration of 1 mol / L and stirred at 30°C for 12 hours for ion exchange. The product was then filtered, washed three times with anhydrous methanol, and dried in a vacuum oven at 70°C for 18 hours to obtain the ionomer backbone.

[0052] S3. The ionomer framework treated in step S2 is mixed with lithium salt to form a film. The ionomer backbone obtained in step S2 was dissolved in hexafluoroisopropanol to prepare a solution with a solid content of 15 wt%. A lithium salt comprising lithium bis(trifluoromethanesulfonyl)imide and lithium difluorooxalateborate in a mass ratio of 3:1 was added, and the mixture was stirred at room temperature for 3 hours until homogeneous. The solution was coated onto a polytetrafluoroethylene mold, and the solvent evaporation rate was controlled at 1.0 μm / min for 12 hours at 50°C and 20% relative humidity. Subsequently, the mixture was placed in a vacuum oven and dried at 70°C for 18 hours to obtain a polymer solid electrolyte membrane with a thickness of 40 μm.

[0053] Comparative Example 1 This comparative example is the same as Example 1, except that no sulfonated monomer was added.

[0054] S1. Preparation of ionomer framework via melt polycondensation 76.7g of succinic acid, 21.9g of adipic acid, 24.9g of terephthalic acid, 8.3g of isophthalic acid, and 99.1g of 1,4-butanediol were weighed and added to a reactor. Then, 0.62g of tetrabutyl titanate catalyst and 0.12g of triphenyl phosphite heat stabilizer were added. Under nitrogen protection, the mixture was heated to 175℃ and subjected to esterification at atmospheric pressure for 3 hours. Water, a byproduct, was collected during the reaction using a water separator. Esterification ended when the acid value dropped below 20mgKOH / g. The reaction system was then slowly heated to 225℃ and gradually evacuated to below 100Pa. Polycondensation was carried out for 4 hours until the weight-average molecular weight reached 60,000g / mol, at which point the reaction was stopped. Nitrogen was introduced to restore atmospheric pressure, the mixture was discharged, cooled, and pelletized to obtain the ionomer skeleton.

[0055] S2, Mixing the ionomer framework with lithium salt to form a film. The ionomer backbone obtained in step S1 was dissolved in hexafluoroisopropanol to prepare a solution with a solid content of 15 wt%. A lithium salt comprising lithium bis(trifluoromethanesulfonyl)imide and lithium difluorooxalateborate in a mass ratio of 3:1 was added, and the mixture was stirred at room temperature for 3 hours until homogeneous. The solution was coated onto a polytetrafluoroethylene mold, and the solvent evaporation rate was controlled at 1.5 μm / min for 10 hours at 50°C and 20% relative humidity. Subsequently, the mixture was placed in a vacuum oven and dried at 70°C for 18 hours to obtain a polymer solid electrolyte membrane with a thickness of 40 μm.

[0056] Comparative Example 2 The only difference between this comparative example and Example 1 is that the amount of sulfonated monomer added is increased.

[0057] S1. Preparation of ionomer framework intermediates via melt polycondensation 53.1g of succinic acid, 11.8g of adipic acid, 24.9g of terephthalic acid, 8.3g of isophthalic acid, 74.0g of sodium isophthalate-5-sulfonate, and 99.1g of 1,4-butanediol were weighed and added to a reactor. Then, 0.62g of tetrabutyl titanate catalyst and 0.12g of triphenyl phosphite heat stabilizer were added. Under nitrogen protection, the mixture was heated to 175℃ and subjected to esterification at atmospheric pressure for 3 hours. Water, a byproduct, was collected during the reaction using a water separator. Esterification ended when the acid value dropped below 20mgKOH / g. The reaction system was then slowly heated to 225℃ and gradually evacuated to below 100Pa. Polycondensation was carried out for 4 hours until the weight-average molecular weight reached 60,000g / mol, at which point the reaction was stopped. Nitrogen was introduced to restore atmospheric pressure, the mixture was discharged, cooled, and pelletized to obtain an ionomer backbone intermediate.

[0058] S2. Lithylating the ionomer backbone intermediate to obtain the ionomer backbone. The ionomer backbone intermediate obtained in step S1 was immersed in a methanol / water mixed solution (volume ratio 2:1) with a lithium hydroxide concentration of 1 mol / L and stirred at 30°C for 12 hours for ion exchange. The product was then filtered, washed three times with anhydrous methanol, and dried in a vacuum oven at 70°C for 18 hours to obtain the ionomer backbone.

[0059] S3. The ionomer framework treated in step S2 is mixed with lithium salt to form a film. The ionomer backbone obtained in step S2 was dissolved in hexafluoroisopropanol to prepare a solution with a solid content of 15 wt%. A lithium salt comprising lithium bis(trifluoromethanesulfonyl)imide and lithium difluorooxalateborate in a mass ratio of 3:1 was added, and the mixture was stirred at room temperature for 3 hours until homogeneous. The solution was coated onto a polytetrafluoroethylene mold, and the solvent evaporation rate was controlled at 1.5 μm / min for 10 hours at 50°C and 20% relative humidity. Subsequently, the mixture was placed in a vacuum oven and dried at 70°C for 18 hours to obtain a polymer solid electrolyte membrane with a thickness of 40 μm.

[0060] Comparative Example 3 The only difference between this comparative example and Example 1 is that the polycondensation reaction was terminated earlier, and the reaction was stopped when the weight-average molecular weight reached 20,000 g / mol.

[0061] S1. Preparation of ionomer framework intermediates via melt polycondensation 64.9g of succinic acid, 21.9g of adipic acid, 24.9g of terephthalic acid, 8.3g of isophthalic acid, 29.6g of sodium isophthalate-5-sulfonate, and 99.1g of 1,4-butanediol were weighed and added to a reactor. Then, 0.62g of tetrabutyl titanate catalyst and 0.12g of triphenyl phosphite heat stabilizer were added. Under nitrogen protection, the mixture was heated to 175℃ and subjected to esterification at atmospheric pressure for 3 hours. Water, a byproduct, was collected during the reaction using a water separator. Esterification ended when the acid value dropped below 20mgKOH / g. The reaction system was then slowly heated to 225℃ and gradually evacuated to below 100Pa. Polycondensation was carried out for approximately 2 hours until the weight-average molecular weight reached 20000g / mol. Nitrogen was introduced to restore atmospheric pressure, the mixture was discharged, cooled, and pelletized to obtain an ionomer backbone intermediate.

[0062] S2. Lithylating the ionomer backbone intermediate to obtain the ionomer backbone. The ionomer backbone intermediate obtained in step S1 was immersed in a methanol / water mixed solution (volume ratio 2:1) with a lithium hydroxide concentration of 1 mol / L and stirred at 30°C for 12 hours for ion exchange. The product was then filtered, washed three times with anhydrous methanol, and dried in a vacuum oven at 70°C for 18 hours to obtain the ionomer backbone.

[0063] S3. The ionomer framework treated in step S2 is mixed with lithium salt to form a film. The ionomer backbone obtained in step S2 was dissolved in hexafluoroisopropanol to prepare a solution with a solid content of 15 wt%. A lithium salt comprising lithium bis(trifluoromethanesulfonyl)imide and lithium difluorooxalateborate in a mass ratio of 3:1 was added, and the mixture was stirred at room temperature for 3 hours until homogeneous. The solution was coated onto a polytetrafluoroethylene mold, and the solvent evaporation rate was controlled at 1.5 μm / min for 10 hours at 50°C and 20% relative humidity. Subsequently, the mixture was placed in a vacuum oven and dried at 70°C for 18 hours to obtain a polymer solid electrolyte membrane with a thickness of 40 μm.

[0064] Comparative Example 4 The only difference between this comparative example and Example 1 is that the solvent evaporation rate is increased to 8 μm / min in step S3.

[0065] S1. Preparation of ionomer framework intermediates via melt polycondensation 64.9g of succinic acid, 21.9g of adipic acid, 24.9g of terephthalic acid, 8.3g of isophthalic acid, 29.6g of sodium isophthalate-5-sulfonate, and 99.1g of 1,4-butanediol were weighed and added to a reactor. Then, 0.62g of tetrabutyl titanate catalyst and 0.12g of triphenyl phosphite heat stabilizer were added. Under nitrogen protection, the mixture was heated to 175℃ and subjected to esterification at atmospheric pressure for 3 hours. Water, a byproduct, was collected during the reaction using a water separator. Esterification ended when the acid value dropped below 20mgKOH / g. The reaction system was then slowly heated to 225℃ and gradually evacuated to below 100Pa. Polycondensation was carried out for 4 hours until the weight-average molecular weight reached 60,000g / mol, at which point the reaction was stopped. Nitrogen was introduced to restore atmospheric pressure, the mixture was discharged, cooled, and pelletized to obtain an ionomer backbone intermediate.

[0066] S2. Lithylating the ionomer backbone intermediate to obtain the ionomer backbone. The ionomer backbone intermediate obtained in step S1 was immersed in a methanol / water mixed solution (volume ratio 2:1) with a lithium hydroxide concentration of 1 mol / L and stirred at 30°C for 12 hours for ion exchange. The product was then filtered, washed three times with anhydrous methanol, and dried in a vacuum oven at 70°C for 18 hours to obtain the ionomer backbone.

[0067] S3. The ionomer framework treated in step S2 is mixed with lithium salt to form a film. The ionomer backbone obtained in step S2 was dissolved in hexafluoroisopropanol to prepare a solution with a solid content of 15 wt%. A lithium salt comprising lithium bis(trifluoromethanesulfonyl)imide and lithium difluorooxalateborate in a mass ratio of 3:1 was added, and the mixture was stirred at room temperature for 3 hours until homogeneous. The solution was coated onto a polytetrafluoroethylene mold, and the solvent evaporation rate was controlled at 8 μm / min for 3 hours at 50°C and 20% relative humidity. Subsequently, the mixture was placed in a vacuum oven and dried at 70°C for 18 hours to obtain a polymer solid electrolyte membrane with a thickness of 40 μm.

[0068] Comparative Example 5 The only difference between this comparative example and Example 1 is that terephthalic acid and isophthalic acid were not added to the raw materials, and their molar ratios were allocated to succinic acid accordingly. All other process parameters were exactly the same.

[0069] S1. Preparation of ionomer framework intermediates via melt polycondensation 88.5g of succinic acid, 21.9g of adipic acid, 29.6g of sodium isophthalic acid-5-sulfonate, and 99.1g of 1,4-butanediol were weighed and added to a reactor. Then, 0.62g of tetrabutyl titanate catalyst and 0.12g of triphenyl phosphite heat stabilizer were added. Under nitrogen protection, the mixture was heated to 175℃ and subjected to esterification at atmospheric pressure for 3 hours. Water, a byproduct, was collected during the reaction using a water separator. Esterification ended when the acid value dropped below 20mgKOH / g. The reaction system was then slowly heated to 225℃ and gradually evacuated to below 100Pa. Polycondensation was carried out for 4 hours until the weight-average molecular weight reached 60,000g / mol, at which point the reaction was stopped. Nitrogen was introduced to restore atmospheric pressure, the mixture was discharged, cooled, and pelletized to obtain an ionomer backbone intermediate.

[0070] S2. Lithylating the ionomer backbone intermediate to obtain the ionomer backbone. The ionomer backbone intermediate obtained in step S1 was immersed in a methanol / water mixed solution (volume ratio 2:1) with a lithium hydroxide concentration of 1 mol / L and stirred at 30°C for 12 hours for ion exchange. The product was then filtered, washed three times with anhydrous methanol, and dried in a vacuum oven at 70°C for 18 hours to obtain the ionomer backbone.

[0071] S3. The ionomer framework treated in step S2 is mixed with lithium salt to form a film. The ionomer backbone obtained in step S2 was dissolved in hexafluoroisopropanol to prepare a solution with a solid content of 15 wt%. A lithium salt comprising lithium bis(trifluoromethanesulfonyl)imide and lithium difluorooxalateborate in a mass ratio of 3:1 was added, and the mixture was stirred at room temperature for 3 hours until homogeneous. The solution was coated onto a polytetrafluoroethylene mold, and the solvent evaporation rate was controlled at 1.5 μm / min for 10 hours at 50°C and 20% relative humidity. Subsequently, the mixture was placed in a vacuum oven and dried at 70°C for 18 hours to obtain a polymer solid electrolyte membrane with a thickness of 40 μm.

[0072] Sample preparation In this invention, the polymer solid electrolyte membranes prepared in the above embodiments and comparative examples are used to construct coin cells, steel-steel systems and lithium-steel systems blocking cells, and lithium-to-lithium symmetric cells for testing.

[0073] The positive electrode material of the coin cell is LiFePO4, and the negative electrode material is lithium metal.

[0074] Experimental Example In this experimental example, the polymer solid electrolyte membranes and button-type membranes prepared in the above embodiments were subjected to the following tests: 1) Crystallinity, melting point and glass transition temperature testing Approximately 5–8 mg of the solid electrolyte membranes finally prepared in each example and comparative example were placed in an aluminum crucible of a differential scanning calorimeter (DSC). Under a nitrogen atmosphere, the temperature was increased from -50°C to 200°C at a heating rate of 10°C / min, and the first heating curve was recorded. Crystallinity was calculated from the enthalpy of fusion, with 110.3 J / g, the enthalpy of fusion of 100% pure PBS crystals, as the baseline; the melting point was taken as the peak temperature of the melting peak; and the glass transition temperature was taken as the midpoint temperature of the heat capacity change step.

[0075] 2) Measurement of ionic conductivity Electrochemical impedance spectroscopy (EIS) was performed on a steel-steel blocked cell system under isothermal conditions of 25℃ and 60℃ using an electrochemical workstation. The frequency range was 1Hz–1MHz, and the AC amplitude was 10mV. The bulk resistance R was read from the intersection of the Nyquist curve and the real axis, and then calculated according to the formula... Calculate the ionic conductivity, where L is the film thickness (measured with a micrometer) and A is the electrode area.

[0076] 3) Lithium-ion transference number ( ) Measurement The Bruce-Vincent method was used to test the symmetrical cell under a constant temperature of 60℃: first, the initial AC impedance of the cell was measured to obtain the initial interface resistance. Then, a 10mV DC polarization voltage is applied, and the current-time curve is recorded until the current approaches a steady-state value. After polarization, the AC impedance was tested again to obtain the steady-state interface resistance. According to the formula Calculate the lithium-ion transference number, where Polarization voltage, This is the initial current.

[0077] 4) Electrochemical stability window determination Blocked batteries of the lithium-steel system were tested using linear sweep voltammetry (LSV), with the scan range from open circuit voltage (approximately 2.5–3.0 V) to 6.0 V and a scan rate of 1 mV / s. The voltage at which the current density began to rise significantly (more than 10 times the baseline current) was taken as the electrochemical stability window.

[0078] The test results are shown in the table below: Crystallinity (%) Melting point (°C) Crystalline phase Tg (°C) Room temperature ionic conductivity (S / cm) Ion transport number Electrochemical window (V) Example 1 28.5 158 112 <![CDATA[1.28×10 -4 ]]> 0.88 4.8 Example 2 24.2 182 125 <![CDATA[7.74×10 -5 ]]> 0.86 5.0 Example 3 20.8 138 101 <![CDATA[1.62×10 -4 ]]> 0.84 4.6 Example 4 32.6 165 118 <![CDATA[8.35×10 -5 ]]> 0.89 4.7 Example 5 25.4 148 106 <![CDATA[1.41×10 -4 ]]> 0.87 4.7 Example 6 26.8 175 120 <![CDATA[9.18×10 -5 ]]> 0.88 4.9 Example 7 41.5 172 120 <![CDATA[9.52×10 -5 ]]> 0.88 4.9 Comparative Example 1 31.5 162 115 <![CDATA[2.35×10 -4 ]]> 0.42 4.5 Comparative Example 2 14.2 132 88 <![CDATA[1.86×10 -4 ]]> 0.85 4.6 Comparative Example 3 21.8 135 99 <![CDATA[8.85×10 -5 ]]> 0.86 4.7 Comparative Example 4 22.4 156 112 <![CDATA[3.52×10 -5 ]]> 0.87 4.7 Comparative Example 5 38.2 112 - <![CDATA[1.32×10 -4 ]]> 0.86 4.7 The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. The implementation schemes in the above embodiments can also be further combined or replaced. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A polymer solid electrolyte membrane, characterized in that, It includes an ionomer framework and a lithium salt, wherein the ionomer framework is prepared by melt polycondensation and lithiation of C4-C10 aliphatic dicarboxylic acids, C8-C20 aromatic dicarboxylic acids or their esters, sulfonated monomers and C2-C10 aliphatic diols. The sulfonated monomer is an aromatic or aliphatic dicarboxylic acid or its ester derivative containing at least one sulfonic acid group.

2. The polymer solid electrolyte membrane according to claim 1, characterized in that, The C2-C10 aliphatic dicarboxylic acid is selected from at least one of succinic acid, glutaric acid, adipic acid, pimelic acid, and octanoic acid; the C8-C20 aromatic dicarboxylic acid is selected from at least one of terephthalic acid, dimethyl terephthalate, isophthalic acid, dimethyl isophthalate, phthalic acid, phthalic anhydride, 2,6-naphthalenedicarboxylic acid, and dimethyl 2,6-naphthalenedicarboxylic acid; the sulfonated monomer is selected from at least one of sodium isophthalate-5-sulfonate, sodium 1,2-(dimethoxycarbonyl)ethanesulfonate, sulfosuccinic acid, 4-sulfophthalic acid, and sulfonaphthalenedicarboxylic acid; the aliphatic diol is selected from at least one of ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentanediol, diethylene glycol, and 1,4-cyclohexanediethanol.

3. The polymer solid electrolyte membrane according to claim 2, characterized in that, The C2-C10 aliphatic dicarboxylic acid is at least one of succinic acid and adipic acid; the C8-C20 aromatic dicarboxylic acid is at least one of terephthalic acid, dimethyl terephthalate, isophthalic acid, and dimethyl isophthalate; the sulfonated monomer is at least one of sodium isophthalate-5-sulfonate, sodium 1,2-(dimethoxycarbonyl)ethanesulfonate, and sulfosuccinic acid; the C2-C10 aliphatic diol is at least one of 1,4-butanediol, 1,6-hexanediol, diethylene glycol, and 1,4-cyclohexanediethanol.

4. The polymer solid electrolyte membrane according to any one of claims 1-3, characterized in that, The mass percentage of the raw materials used to prepare the ionomer framework is as follows: C4-C10 aliphatic dicarboxylic acids: 25%-60% C8-C20 aromatic dicarboxylic acids or their esters: 5%-30% Sulfonated monomers: 5%-25% C2-C10 aliphatic diols: 15%-45%; Furthermore, the molar ratio of carboxyl groups in all dicarboxylic acid monomers to hydroxyl groups in all diol monomers is in the range of 1:(1-1.3). Preferably, the mass ratio of the raw materials used to prepare the ionomer framework is: C4-C10 aliphatic dicarboxylic acids: 35%-55% C8-C20 aromatic dicarboxylic acids or their esters: 10%-25% Sulfonated monomers: 10%-20% C2-C10 aliphatic diols: 20%-45%.

5. The polymer solid electrolyte membrane according to claim 1, characterized in that, The lithium salt is selected from at least one of lithium tetrafluoroborate, lithium bis(trifluoromethanesulfonyl)imide, lithium difluorooxalate borate, lithium bis(fluorosulfonyl)imide, and lithium bis(oxalate borate).

6. The polymer solid electrolyte membrane according to claim 1, characterized in that, The weight-average molecular weight of the ionomer backbone is in the range of 30,000-100,000 g / mol, and the crystallinity is in the range of 18%-45%; preferably, the crystallinity is in the range of 20%-45%; more preferably, the crystallinity is in the range of 25%-40%.

7. A method for preparing a polymer solid electrolyte membrane as described in any one of claims 1-5, characterized in that, Includes the following steps: S1. Preparation of ionomer framework intermediates via melt polycondensation; S2. The ionomer backbone intermediate is lithiated to obtain the ionomer backbone. S3. The ionomer framework treated in step S2 is mixed with lithium salt to form a film.

8. The method for preparing the polymer solid electrolyte membrane according to claim 7, characterized in that, Step S1 is as follows: Weighed C4-C10 aliphatic dicarboxylic acids, C8-C20 aromatic dicarboxylic acids or their esters, sulfonated monomers and C2-C10 aliphatic diols are mixed and then a catalyst is added. Esterification is carried out at 160℃-190℃ under normal pressure in a protective atmosphere until the acid value of the reactants reaches or is less than the preset acid value threshold. Then, the temperature is raised to 200℃-245℃ and polycondensation is carried out under vacuum to obtain an ionomer skeleton intermediate.

9. The method for preparing the polymer solid electrolyte membrane according to claim 8, characterized in that, In step S1, the preset acid value threshold is 20 mg KOH / g; the polycondensation reaction is stopped when the weight-average molecular weight of the product reaches 30,000–100,000 g / mol, and the ionomer skeleton intermediate is obtained.

10. The method for preparing the polymer solid electrolyte membrane according to claim 7, characterized in that, Step S2 specifically involves immersing the ionomer framework intermediate obtained in step S1 in an alkaline solution containing lithium ions for ion exchange, followed by filtration, washing, and vacuum drying to obtain the ionomer framework.

11. The method for preparing the polymer solid electrolyte membrane according to claim 10, characterized in that, The alkaline solution containing lithium ions is an alcohol / water mixture of at least one of lithium hydroxide and lithium carbonate, and the ion exchange process is as follows: continuous stirring at 25℃-40℃ for 6-18 hours.

12. The method for preparing the polymer solid electrolyte membrane according to claim 7, characterized in that, Step S3 specifically involves: preparing the ionomer framework obtained in step S2 into a solution, adding lithium salt to the solution, mixing, and pouring into a mold. The solvent evaporation rate is controlled at 0.5-3 μm / min and maintained at a temperature of 40℃-60℃ and a relative humidity of less than 30% for 6-18 hours. Then, the polymer solid electrolyte membrane is obtained by vacuum drying. The mass ratio of the ionomer framework to the lithium salt is 1:(0.08-0.14).

13. The method for preparing the polymer solid electrolyte membrane according to claim 12, characterized in that, The solvent for the ionomer skeleton is a fluoroalcohol solvent; preferably hexafluoroisopropanol.

14. The method for preparing the polymer solid electrolyte membrane according to claim 7, characterized in that, Step S3 specifically involves uniformly mixing the ionomer framework obtained in step S2 with lithium salt, and then hot-pressing it for 5-15 minutes at a temperature of 120℃-180℃ and a pressure of 5-15MPa to obtain a polymer solid electrolyte membrane.