Preparation method and application of amidoxime-modified inherently microporous polymer-based solid electrolyte

Abstract

The present invention discloses a preparation method and application of an amide oxime-modified inherently microporous polymer-based solid electrolyte, belonging to the technical field of solid-state lithium metal batteries. The preparation method of the amide oxime-modified inherently microporous polymer-based solid electrolyte includes the preparation and optimization conditions of amide oxime-modified inherently microporous polymer-based solid electrolyte particles and their self-supporting electrolyte membrane. The amide oxime-modified inherently microporous polymer-based solid electrolyte in the present invention has the advantages of high ion conductivity, high lithium ion migration number, good stability and excellent mechanical properties, effectively solving the problems of poor ion conductivity, poor stability and large grain boundary impedance of solid electrolytes in existing solid-state lithium metal batteries, and at the same time overcoming the problems of large capacity loss caused by non-conductive binder ions in the solid positive electrode and loose bonding between ion conductive materials and conductive materials.

Description

Technical Field

[0001] The present invention relates to the field of solid-state lithium metal batteries, and in particular to a preparation method and application of an amide oxime-modified inherently microporous polymer-based solid electrolyte. Background Art

[0002] The rapid development of new energy vehicles and smart grid technologies has put forward higher requirements on the safety, energy density and cyclability of lithium-ion batteries. Lithium metal batteries have low redox potential (-3.04V, compared with standard hydrogen electrode) and high theoretical specific capacity (3860mAhg −1 ) are regarded as promising candidates for advanced energy storage devices. However, the use of lithium metal batteries is limited due to safety hazards such as the growth of lithium dendrites, flammability and leakage of liquid electrolytes. By replacing liquid electrolytes with non-flammable solid electrolytes, solid-state lithium metal batteries are expected to achieve high specific energy, long cycle life and high safety. Two types of solid electrolytes are generally used: inorganic solid electrolytes and polymer electrolytes. Inorganic solid electrolytes have high ionic conductivity, electrochemical stability window and mechanical strength, but the solid / solid contact resistance between the electrode and the electrolyte is large. Polymer solid electrolytes have good flexibility, processability and contact interface properties, but the room temperature ionic conductivity is low and they need to operate at high temperatures. Therefore, there is an urgent need to develop a new category of electrolytes that can provide high ionic conductivity, good lithium ion mobility and long-term interface stability.

[0003] Intrinsically microporous polymers are a class of amorphous microporous polymers with rigid polymer chains. They possess very high specific surface areas. Due to the presence of various rigid and distorted structures within the molecules, the polymers cannot effectively stack when forming dense packing, resulting in a large number of micropores (most of which are below 2 nm in size). These structural characteristics give them broad application prospects in the field of adsorption separation. Leveraging the concept of intrinsic micropores, intrinsically microporous polymers have also been designed for applications in a wide range of environmental protection and energy fields, such as fuel cells, lithium batteries, and uranium extraction from seawater. Thanks to their size-exclusion-induced selectivity and free-volume-induced permeability, intrinsically microporous polymers are becoming the next generation of molecular separation and ion transport membranes. Therefore, it is promising to develop novel solid-state electrolytes based on intrinsically microporous polymers that combine high ionic conductivity, high stability, and long-term interfacial stability.

[0004] The current research difficulties of solid electrolytes are mainly in three aspects: (1) Solid electrolytes cannot meet the requirements of high ionic conductivity (>10 −3S / cm), which limits the ion transfer efficiency and the fast charging performance cannot be compared with the electrolyte; (2) the liquid-solid interface corresponding to the electrolyte is in perfect contact, while the solid-solid interface is prone to poor contact, especially after multiple charge and discharge cycles, mechanical stress leads to contact failure; (3) the chemical and electrochemical compatibility between the electrolyte and the electrode is difficult to balance with other properties, especially when using lithium metal negative electrodes. At present, the strategies for modifying single-component solid electrolytes are difficult to meet all the performance requirements of solid-state lithium batteries for electrolytes. By combining inorganic materials and organic polymers, their respective excellent properties can be fully utilized, but the preparation process is complicated and ion migration is hindered. PIM-1, an intrinsically microporous polymer with high free volume fraction and high porosity, is an ideal electrolyte matrix. However, the gas selectivity of the current PIM-1 membrane is relatively low, and physical aging and plasticization phenomena are obvious. In addition, how ions are coordinated and transported in the PIM-1 structure has rarely been studied and reported.

[0005] Therefore, it is necessary to provide a preparation method and application of an amide oxime-modified inherently microporous polymer-based solid electrolyte to solve the above problems. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of the embodiments of the present invention is to provide a preparation method and application of an amide oxime-modified inherently microporous polymer-based solid electrolyte to solve the problems in the above-mentioned background technology.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A method for preparing an amide oxime-modified intrinsically microporous polymer-based solid electrolyte comprises the following steps:

[0009] Step S1, dissolving 5,5',6,6'-tetrahydroxy-3,3,3',3'-tetramethyl-1,1'-spirobiindole and 2,3,5,6-tetrafluoroterephthalonitrile in anhydrous N,N-dimethylformamide solution in a certain molar ratio, transferring the reaction solution to a reaction bottle, and stirring until the monomers are dissolved to form a clear solution;

[0010] Step S2: adding a certain proportion of anhydrous potassium carbonate to the above clear solution, stirring thoroughly, immersing the reaction flask in a preheated oil bath at 65° C., and stirring under an argon atmosphere for 70-80 hours;

[0011] Step S3: After cooling, pour the solution obtained in step S2 into a beaker containing 650 mL of purified water, collect the precipitate by filtration, dissolve the precipitate in 200 mL of chloroform solution, and precipitate it from 500 mL of methanol solution;

[0012] Step S4: dissolving the precipitate obtained in step S3 in 200 mL of tetrahydrofuran solution and adding the solution to 600 mL of an acetone-tetrahydrofuran mixture for further precipitation. The precipitated product was collected by vacuum filtration, and then the precipitate was washed with 80 mL of 1,4-dioxane, 80 mL of acetone, and another 50 mL of acetone.

[0013] Step S5: The resulting product was dried in an oven at 110° C. for 12 h to obtain PIM-1 as a bright yellow solid. In a three-necked flask equipped with a spiral condenser, a thermocouple, and a magnetic stirrer, 0.6 g of PIM-1 powder was dissolved in 40 mL of tetrahydrofuran and heated to 65° C. under an inert gas atmosphere.

[0014] Step S6, adding 0.6 mL of hydroxylamine dropwise to the clear solution obtained in step S5, forming a precipitate of a dissolved turbid solution after 20 minutes, and heating to 69° C. and reflux for 20 hours. After the reaction is completed, cooling to room temperature and adding 150 mL of ethanol to form an off-white precipitate, filtering the precipitate and washing it with ethanol several times;

[0015] Step S7: heating and drying the obtained product in an oven at 110° C. for 12 h to obtain amide oxime-modified AO-PIM-1 as a light yellow solid; dissolving the AO-PIM-1 powder in a lithium salt solution of a certain concentration and performing ion exchange for a certain period of time to obtain AO-PIM-1-Li powder having ion conductivity;

[0016] Step S8, dissolving AO-PIM-1-Li in a N,N-dimethylformamide solution at a certain molar ratio, and centrifuging to remove undissolved matter to obtain a uniform polymer solution;

[0017] Step S9: pouring the polymer solution into a polytetrafluoroethylene surface dish, and transferring the solution into an oven to evaporate the solution, thereby obtaining a dry self-supporting electrolyte membrane.

[0018] As a further embodiment of the present invention, the molar ratio of 5,5',6,6'-tetrahydroxy-3,3,3',3'-tetramethyl-1,1'-spirobiindole to 2,3,5,6-tetrafluoroterephthalonitrile in step S1 is 1:1.

[0019] As a further embodiment of the present invention, the ratio of potassium carbonate to 2,3,5,6-tetrafluoroterephthalonitrile in step S2 is 2:1.

[0020] As a further solution of the present invention, the lithium salt solution in step S7 is a solution of lithium bis(trifluoromethane)sulfonyl imide and tetraethylene glycol dimethyl ether.

[0021] As a further solution of the present invention, the concentration of the lithium salt solution in step S7 is 1 mol / L.

[0022] As a further solution of the present invention, the ion exchange time in step S7 is 20-24 hours.

[0023] As a further embodiment of the present invention, the molar ratio of AO-PIM-1-Li in step S8 is 0.5-2 mol / L.

[0024] As a further embodiment of the present invention, the temperature for evaporating the polymer in step S9 is 60°C-80°C.

[0025] The present invention provides an amide oxime-modified inherent microporous polymer-based solid electrolyte prepared by the preparation method.

[0026] The present invention provides an application of an amide oxime-modified inherent microporous polymer-based solid electrolyte in the preparation of a solid-state lithium battery.

[0027] In summary, the embodiments of the present invention have the following beneficial effects compared with the prior art:

[0028] 1. The amidoxime-modified inherently microporous polymer-based solid electrolyte of the present invention exhibits high ionic conductivity, a high lithium ion transference number, and good chemical, electrochemical, and air stability, resolving the difficulty of existing solid electrolyte materials in achieving both high ion transport capacity and high stability.

[0029] 2. The amidoxime-modified inherently microporous polymer-based solid electrolyte membrane prepared in this invention has excellent mechanical properties and can recover its original shape after bending and folding. Thanks to its soft texture, it can effectively inhibit the formation of lithium dendrites during the cycling process of solid-state batteries.

[0030] 3. The amidoxime-modified inherently microporous polymer-based solid-state positive electrode in the present invention effectively solves the problem of capacity loss caused by the non-conductivity of the binder ions in the positive electrode of existing solid-state lithium metal batteries. At the same time, it overcomes the problems of loose bonding between ion conductive materials and conductive materials, poor ion / electronic conductivity, and poor chemical / electrochemical / air stability.

[0031] In order to more clearly illustrate the structural features and effects of the present invention, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a scanning electron microscope image of the AO-PIM-1-Li solid electrolyte membrane prepared in Example 1 of the present invention;

[0033] Figure 2Impedance curves of the AO-PIM-1-Li solid electrolyte membrane prepared in Example 1 of the present invention at different temperatures;

[0034] Figure 3 These are optical photographs of the AO-PIM-1-Li solid electrolyte membrane prepared in Example 1 of the present invention under different conditions;

[0035] Figure 4 This is a scanning electron microscope image of the AO-PIM-1-Li / LiFePO4 solid cathode material prepared in Example 2 of the present invention;

[0036] Figure 5 Comparison of the cycling performance of the solid-state lithium metal battery prepared in Example 3 of the present invention and the solid-state lithium metal battery prepared in Comparative Example 3;

[0037] Figure 6 The cycling performance of the solid-state lithium metal soft-pack battery prepared in Example 4 of the present invention under different mechanical conditions;

[0038] Figure 7 Comparison of charge and discharge performance of the solid-state lithium-air battery prepared in Example 5 of the present invention and the solid-state lithium-air battery prepared in Comparative Example 4;

[0039] Figure 8 The cycle performance of the solid-state lithium-air battery prepared in Example 5 of the present invention is compared with that of the solid-state lithium-air battery prepared in Comparative Example 4;

[0040] Figure 9 The morphology and thickness of the solid electrolyte membrane of Comparative Example 1 of the present invention are characterized. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0042] The specific implementation of the present invention is described in detail below with reference to specific embodiments.

[0043] Example 1

[0044] Preparation of AO-PIM-1-Li solid electrolyte membrane:

[0045] 1. Weigh 4.9655 g of 5,5',6,6'-tetrahydroxy-3,3,3',3'-tetramethyl-1,1'-spirobiindole and 2.9187 g of 2,3,5,6-tetrafluoroterephthalonitrile and dissolve them in 73 mL of anhydrous N,N-dimethylformamide solution.

[0046] 2. Transfer the above reaction solution to a reaction flask and stir it thoroughly at 200 r / min until the monomer is dissolved to form a clear solution. Then add 4.0318 g of anhydrous potassium carbonate. After stirring thoroughly, immerse the reaction flask in a preheated oil bath at 65°C and stir under argon atmosphere for 72 hours.

[0047] 3. After cooling, the solution obtained in step 2 was poured into a beaker containing 650 mL of purified water. The precipitate was collected by filtration and washed with chloroform, methanol, tetrahydrofuran, 1,4-dioxane, and acetone for purification. The resulting product was heated and dried in an oven at 110°C for 12 h to obtain PIM-1 as a bright yellow solid.

[0048] 4. In a three-necked flask equipped with a spiral condenser, a thermocouple, and a magnetic stirrer, 0.6 g of PIM-1 powder was dissolved in 40 mL of tetrahydrofuran. After heating to 65°C under an inert gas atmosphere, 0.6 mL of hydroxylamine was added dropwise to the clear solution. After 20 minutes, a precipitate was formed in the dissolved turbid solution, which was then heated to 69°C and refluxed for 20 h.

[0049] 5. After the reaction is completed, cool to room temperature and add 150 mL of ethanol to form an off-white precipitate. Filter the precipitate and wash with ethanol 3-5 times. Heat and dry the resulting product in an oven at 110°C for 12 h to obtain amide oxime-modified PIM-1 (AO-PIM-1) as a light yellow solid.

[0050] 6. Dissolve the AO-PIM-1 powder in a 1 mol / L lithium salt solution and perform ion exchange for a certain period of time to obtain AO-PIM-1-Li powder with ion conductivity.

[0051] 7. AO-PIM-1-Li was dissolved in N,N-dimethylformamide solution at a molar ratio of 1 mol / L and centrifuged to remove insoluble matter to obtain a uniform polymer solution. The polymer solution was then cast into a polytetrafluoroethylene surface dish (10 cm × 10 cm) and transferred to an oven at 60°C to slowly evaporate the solution to obtain a dry self-supporting electrolyte membrane.

[0052] The filtered precipitate is preferably washed with ethanol four times, the ion exchange time is preferably 20-24 h, the lithium salt solution is preferably lithium bis(trifluoromethane)sulfonyl imide / tetraethylene glycol dimethyl ether solution, the molar ratio of AO-PIM-1-Li is preferably 0.5-2 mol / L, and the polymer evaporation temperature is preferably 60° C.-80° C.

[0053] The AO-PIM-1-Li solid electrolyte membrane prepared in Example 1 of the present invention was characterized.

[0054] See also Figure 1 , Figure 1This is a scanning electron microscope image of the AO-PIM-1-Li solid electrolyte membrane prepared in Example 1.

[0055] Depend on Figure 1 It can be seen that the AO-PIM-1-Li solid electrolyte membrane prepared in the present invention is uniform and dense, with a thickness of 150 μm.

[0056] The performance of the AO-PIM-1-Li solid electrolyte membrane prepared in Example 1 of the present invention was tested.

[0057] The AO-PIM-1-Li solid electrolyte membrane was punched into a disc with a diameter of 16 mm, and silver glue was coated on both sides for ionic conductivity testing.

[0058] See also Figure 2 , Figure 2 Impedance curves of the AO-PIM-1-Li solid electrolyte membrane prepared in Example 1 at different temperatures.

[0059] Depend on Figure 2 The curve can be calculated and the ionic conductivity of AO-PIM-1-Li solid electrolyte membrane is 1.03mScm −1 .

[0060] The mechanical properties of the AO-PIM-1-Li solid electrolyte membrane prepared in Example 1 of the present invention were tested.

[0061] See also Figure 3 , Figure 3 These are optical photographs of the AO-PIM-1-Li solid electrolyte membrane prepared in Example 1 under different conditions.

[0062] Depend on Figure 3 It can be seen that the AO-PIM-1-Li solid electrolyte membrane prepared in the present invention can restore its original shape after bending, folding and load-bearing tests.

[0063] Example 2

[0064] Preparation of AO-PIM-1-Li / LiFePO4 solid cathode material:

[0065] 1. Add AO-PIM-1-Li to N,N-dimethylformamide solution at a molar ratio of 2 mol / L.

[0066] 2. Dissolve lithium iron phosphate and SuperP into the above AO-PIM-1-Li solution in a ratio of 8:2.

[0067] 3. The above solution was evenly coated onto aluminum foil using a scraper with a thickness of 100 μm to obtain a solid-state positive electrode for a solid-state lithium metal battery.

[0068] Wherein, the molar ratio of AO-PIM-1-Li is set to 0.5-2 mol / L, preferably 2 mol / L;

[0069] The ratio of lithium iron phosphate to the conductive agent is set to 8:2-9:1, preferably 8:2.

[0070] The AO-PIM-1-Li / LiFePO4 solid cathode material prepared in Example 2 of the present invention was characterized.

[0071] See also Figure 4 , Figure 4 This is a scanning electron microscope image of the AO-PIM-1-Li / LiFePO4 solid positive electrode material prepared in Example 2.

[0072] Depend on Figure 4 It can be seen that the AO-PIM-1-Li / LiFePO4 solid cathode material prepared in the present invention has a continuous structure, and the surface of LiFePO4 is uniformly coated with AO-PIM-1-Li having ion conductivity.

[0073] Therefore, the solid-state positive electrode prepared by the present invention has continuous ion / electron transmission capability.

[0074] Example 3

[0075] Assemble AO-PIM-1-Li into solid-state lithium metal batteries:

[0076] The battery includes a metallic lithium negative electrode, an AO-PIM-1-Li solid electrolyte membrane, and an AO-PIM-1-Li / LiFePO4 solid positive electrode material.

[0077] The charge and discharge performance test of the solid-state lithium metal battery prepared in Example 3 of the present invention was carried out under the following test conditions: room temperature, current density 0.2C, and cut-off voltage of 2.2V-4.35V.

[0078] See also Figure 5 , Figure 5 The cycle performance of the solid-state lithium metal battery prepared in Example 3 is compared with that of the solid-state lithium metal battery prepared in Comparative Example 3.

[0079] Depend on Figure 5 It can be seen that Example 3 has a larger discharge capacity and a longer cycle life at a current density of 0.2C.

[0080] Example 4

[0081] Assemble AO-PIM-1-Li into solid-state lithium metal soft pack batteries:

[0082] The battery includes a metallic lithium negative electrode, an AO-PIM-1-Li solid electrolyte membrane, and an AO-PIM-1-Li / LiFePO4 solid positive electrode material, wherein the metallic lithium negative electrode comprises a lithium sheet, and the thickness of the lithium sheet is preferably 0.2-0.6 mm, more preferably 0.4 mm.

[0083] The solid-state lithium metal soft-pack battery prepared in Example 4 of the present invention was subjected to charge and discharge performance tests under the following test conditions: room temperature, current density 0.2C, and cut-off voltage 2.2V-4.35V.

[0084] See also Figure 6 , Figure 6 The cycling performance of the solid-state lithium metal soft-pack battery prepared in Example 4 under different mechanical conditions.

[0085] Depend on Figure 6 It can be seen that Example 4 can stably cycle 100 times under the conditions of bending and folding.

[0086] Example 5

[0087] Assemble AO-PIM-1-Li into solid-state lithium-air batteries:

[0088] The battery includes a metallic lithium negative electrode, an AO-PIM-1-Li solid electrolyte membrane, and an AO-PIM-1-Li / CNT solid positive electrode material.

[0089] The charge and discharge performance of the solid-state lithium-air battery prepared in Example 5 of the present invention was tested under the following conditions: room temperature, current density 200 mAg −1 , the cut-off voltage is 2V-4.5V.

[0090] See also Figure 7 , Figure 7 The charge and discharge performance of the solid-state lithium-air battery prepared in Example 5 is compared with that of the solid-state lithium-air battery prepared in Comparative Example 4.

[0091] Depend on Figure 7 It can be seen that Example 5 at 200mAg −1 It has a larger discharge capacity at a current density of up to 11307mAg −1 .

[0092] See also Figure 8 , Figure 8 The cycle performance of the solid-state lithium-air battery prepared in Example 5 is compared with that of the solid-state lithium-air battery prepared in Comparative Example 4.

[0093] Depend on Figure 8 It can be seen that Example 5 at 200mAg −1 The current density and 600mAhg −1It has a longer cycle life of up to 247 cycles under the limited capacity.

[0094] Comparative Example 1

[0095] Preparation of PIM-1-Li solid electrolyte membrane:

[0096] 1. Weigh 4.9655 g of 5,5',6,6'-tetrahydroxy-3,3,3',3'-tetramethyl-1,1'-spirobiindole and 2.9187 g of 2,3,5,6-tetrafluoroterephthalonitrile and dissolve them in 73 mL of anhydrous N,N-dimethylformamide solution.

[0097] 2. Transfer the above reaction solution to a reaction flask and stir it thoroughly at 200 r / min until the monomer is dissolved to form a clear solution. Then add 4.0318 g of anhydrous potassium carbonate. After stirring thoroughly, immerse the reaction flask in a preheated oil bath at 65°C and stir under argon atmosphere for 72 hours.

[0098] 3. After cooling, the solution obtained in step 2 was poured into a beaker containing 650 mL of purified water. The precipitate was collected by filtration and washed with chloroform, methanol, tetrahydrofuran, 1,4-dioxane, and acetone for purification. The resulting product was heated and dried in an oven at 110°C for 12 h to obtain PIM-1 as a bright yellow solid.

[0099] 4. Dissolve the PIM-1 powder in a 1 mol / L lithium salt solution and perform ion exchange for a certain period of time to obtain PIM-1-Li powder with ion conductivity.

[0100] 5. PIM-1-Li was dissolved in a dichloromethane solution at a molar ratio of 1 mol / L and centrifuged to remove insoluble matter to obtain a uniform polymer solution. The polymer solution was then cast into a polytetrafluoroethylene surface dish (10 cm × 10 cm) and the solution was slowly evaporated at room temperature to obtain a dry self-supporting electrolyte membrane.

[0101] See also Figure 9 , Figure 9 Characterization of the morphology and thickness of the solid electrolyte membrane of Comparative Example 1.

[0102] Comparative Example 2

[0103] Preparation of PIM-1-Li / LiFePO4 solid cathode material:

[0104] 1. Add PIM-1-Li to dichloromethane solution at a molar ratio of 2 mol / L.

[0105] 2. Dissolve lithium iron phosphate and SuperP into the above PIM-1-Li solution in a ratio of 8:2.

[0106] 3. The above solution was evenly coated onto aluminum foil using a scraper with a thickness of 100 μm to obtain a solid-state positive electrode for a solid-state lithium metal battery.

[0107] Comparative Example 3

[0108] Assemble PIM-1-Li into solid-state lithium metal batteries:

[0109] The battery includes a metallic lithium negative electrode, a PIM-1-Li solid electrolyte membrane, and a PIM-1-Li / LiFePO4 solid positive electrode material.

[0110] See also Figure 5 , the cycle life of the battery of Comparative Example 3 is only 110 cycles.

[0111] Comparative Example 4

[0112] Assemble PIM-1-Li into solid-state lithium-air batteries:

[0113] The battery includes a metallic lithium negative electrode, a PIM-1-Li solid electrolyte membrane, and a PIM-1-Li / CNT solid positive electrode material.

[0114] See also Figure 7 , the discharge capacity of comparative example 4 is only 7100mAhg −1 .

[0115] See also Figure 8 , the cycle life of comparative example 4 is only 100 cycles.

[0116] The beneficial effects that the present invention can produce include:

[0117] (1) The amidoxime-modified inherently microporous polymer-based solid electrolyte of the present invention has high ionic conductivity, high lithium ion transference number, and good chemical / electrochemical / air stability, solving the problem that existing solid electrolyte materials are difficult to achieve both high ion transport capacity and high stability;

[0118] (2) The amidoxime-modified inherently microporous polymer-based solid electrolyte membrane prepared in the present invention has excellent mechanical properties and can recover its original shape after bending and folding. Thanks to its soft texture, it can effectively inhibit the formation of lithium dendrites during the cycling process of solid-state batteries;

[0119] (3) The amidoxime-modified inherent microporous polymer-based solid-state positive electrode of the present invention effectively solves the problem of capacity loss caused by the non-conductivity of the binder ions in the positive electrode of the existing solid-state lithium metal batteries, and overcomes the problems of loose bonding between ion conductive materials and conductive materials, poor ion / electronic conductivity, and poor chemical / electrochemical / air stability.

[0120] Experimental results show that the solid-state lithium metal soft-pack battery using the amide oxime-modified inherently microporous polymer-based solid electrolyte provided by the present invention exhibits excellent mechanical deformation tolerance and can operate stably under bending, folding, cutting and acupuncture.

[0121] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing an amide oxime-modified intrinsically microporous polymer-based solid electrolyte, characterized in that: The following steps are involved: Step S1, dissolving 5,5',6,6'-tetrahydroxy-3,3,3',3'-tetramethyl-1,1'-spirobiindole and 2,3,5,6-tetrafluoroterephthalonitrile in anhydrous N,N-dimethylformamide solution in a certain molar ratio, transferring the reaction solution to a reaction bottle, and stirring until the monomers are dissolved to form a clear solution; Step S2: adding a certain proportion of anhydrous potassium carbonate to the above clear solution, stirring thoroughly, immersing the reaction flask in a preheated oil bath at 65° C., and stirring under an argon atmosphere for 70-80 hours; Step S3: After cooling, pour the solution obtained in step S2 into a beaker containing 650 mL of purified water, collect the precipitate by filtration, dissolve the precipitate in 200 mL of chloroform solution, and precipitate it from 500 mL of methanol solution; Step S4: dissolving the precipitate obtained in step S3 in 200 mL of tetrahydrofuran solution and adding the solution to 600 mL of an acetone-tetrahydrofuran mixture for further precipitation. The precipitated product was collected by vacuum filtration, and then the precipitate was washed with 80 mL of 1,4-dioxane, 80 mL of acetone, and another 50 mL of acetone. Step S5: The resulting product was dried in an oven at 110° C. for 12 h to obtain PIM-1 as a bright yellow solid. In a three-necked flask equipped with a spiral condenser, a thermocouple, and a magnetic stirrer, 0.6 g of PIM-1 powder was dissolved in 40 mL of tetrahydrofuran and heated to 65° C. under an inert gas atmosphere. Step S6, adding 0.6 mL of hydroxylamine dropwise to the clear solution obtained in step S5, forming a precipitate of a dissolved turbid solution after 20 minutes, and heating to 69° C. and reflux for 20 hours. After the reaction is completed, cooling to room temperature and adding 150 mL of ethanol to form an off-white precipitate, filtering the precipitate and washing it with ethanol several times; Step S7: heating and drying the obtained product in an oven at 110° C. for 12 h to obtain amide oxime-modified AO-PIM-1 as a light yellow solid; dissolving the AO-PIM-1 powder in a lithium salt solution of a certain concentration and performing ion exchange for a certain period of time to obtain AO-PIM-1-Li powder having ion conductivity; Step S8, dissolving AO-PIM-1-Li in a N,N-dimethylformamide solution at a certain molar ratio, and centrifuging to remove undissolved matter to obtain a uniform polymer solution; Step S9: pouring the polymer solution into a polytetrafluoroethylene surface dish, and transferring the solution into an oven to evaporate the solution, thereby obtaining a dry self-supporting electrolyte membrane.

2. The method for preparing the amidoxime-modified intrinsically microporous polymer-based solid electrolyte according to claim 1, wherein: The molar ratio of 5,5',6,6'-tetrahydroxy-3,3,3',3'-tetramethyl-1,1'-spirobiindole to 2,3,5,6-tetrafluoroterephthalonitrile in step S1 is 1:

1.

3. The method for preparing the amidoxime-modified intrinsically microporous polymer-based solid electrolyte according to claim 1, wherein: The ratio of potassium carbonate to 2,3,5,6-tetrafluoroterephthalonitrile in step S2 is 2:

1.

4. The method for preparing the amidoxime-modified intrinsically microporous polymer-based solid electrolyte according to claim 1, wherein: The lithium salt solution in step S7 is a solution of lithium bis(trifluoromethane)sulfonyl imide and tetraethylene glycol dimethyl ether.

5. The method for preparing the amidoxime-modified intrinsically microporous polymer-based solid electrolyte according to claim 1, wherein: The concentration of the lithium salt solution in step S7 is 1 mol / L.

6. The method for preparing an amide oxime-modified intrinsically microporous polymer-based solid electrolyte according to claim 1, wherein: The ion exchange time in step S7 is 20-24 hours.

7. The method for preparing an amide oxime-modified intrinsically microporous polymer-based solid electrolyte according to claim 1, wherein: The molar ratio of AO-PIM-1-Li in step S8 is 0.5-2 mol / L.

8. The method for preparing an amide oxime-modified intrinsically microporous polymer-based solid electrolyte according to claim 1, wherein: The temperature of polymer evaporation in step S9 is 60°C-80°C.

9. An amide oxime-modified intrinsically microporous polymer-based solid electrolyte prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the amidoxime-modified intrinsically microporous polymer-based solid electrolyte according to claim 9 in the preparation of a solid-state lithium battery.

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