Multi-scale synergistic structure polymer solid electrolyte and preparation method thereof

Abstract

The preparation method comprises the following steps: S1, preparation of a precursor solution: adding a segmented copolymer, a supramolecular monomer, an inorganic filler, a lithium salt system and a cross-linking agent into a DMF / acetone mixed solvent in proportion, and stirring for dissolving to obtain the precursor solution with the solution concentration of 5-15 wt%; s2, gradient volatilization film formation: uniformly coating the precursor solution on the surface of a base material, regulating and controlling the volatilization rate in three sections at the interval of 30-60 DEG C, and forming an electrolyte film with a vertical orientation nano-channel structure at the relative humidity of 30-70%; s3, hot-pressing cross-linking treatment: placing the electrolyte membrane subjected to gradient volatilization molding in a hot press, maintaining for a period of time under the hot-pressing conditions of 100-150 DEG C and 2-10 MPa, carrying out ring-opening cross-linking reaction on anhydride groups in a cross-linking agent and hydroxyl groups and ether oxygen groups in a block copolymer matrix, and controlling the cross-linking density to be 0.5-3 mol / m < 3 >, so as to obtain the electrolyte membrane. And finally obtaining the polymer solid electrolyte membrane with the multi-scale synergistic structure.

Description

Technical Field

[0001] The present invention relates to the technical field of solid electrolytes, and particularly to a multi-scale cooperative structure polymer solid electrolyte and a preparation method thereof. Background Art

[0002] All-solid-state lithium batteries are regarded as one of the important development directions of next-generation lithium batteries due to their significant advantages in energy density, cycle life, and safety. Compared with traditional liquid electrolyte lithium batteries, all-solid-state lithium batteries have more advantages in performance. Among them, solid polymer electrolytes have become the preferred materials for most all-solid-state lithium batteries due to their good flexibility, simple processing and molding, and excellent compatibility with electrodes, which promotes the rapid development of all-solid-state lithium battery technology.

[0003] Current polymer solid electrolyte technologies face multiple challenges: a) Ion conductivity bottleneck: Traditional PEO-based electrolyte materials have a relatively high room temperature crystallinity (>40%), resulting in generally low Li+ transference numbers, which limits their application in high-performance solid-state batteries. b) Although the addition of inorganic fillers helps to enhance the mechanical strength of polymer-based electrolytes, due to the poor interface between inorganic fillers and the polymer matrix, interface stress concentration often occurs, affecting the overall mechanical properties of the electrolyte. c) Traditional polymer / lithium salt systems are prone to decomposition at higher voltages (such as above 4.5V), resulting in shortened battery life and potential safety hazards.

[0004] Therefore, there is an urgent need for a polymer solid electrolyte to effectively improve the problems of low ionic conductivity and low lithium ion transference number of existing PEO-based solid electrolytes, which lead to poor cycle performance of the battery. Summary of the Invention

[0005] The purpose of the present invention is to provide a multi-scale cooperative structure polymer solid electrolyte and a preparation method thereof. By adopting an innovative optimization design of block copolymers, inorganic fillers, and a dual-lithium salt system, it not only significantly improves the ionic conductivity, mechanical strength, and electrochemical stability of the electrolyte membrane, but also improves the cycle life and safety, and is particularly suitable for high-performance solid-state lithium batteries. These excellent properties make the solid electrolyte membrane of the present invention have broad application prospects in the battery field.

[0006] The technical solution adopted by the present invention to solve the above technical problems is as follows:

[0007] A preparation method of a multi-scale cooperative structure polymer solid electrolyte, comprising the following steps:

[0008] S1. Preparation of precursor solution: Add block copolymer, supramolecular monomer, inorganic filler, lithium salt system and crosslinking agent into the DMF / acetone mixed solvent according to a certain proportion, and stir to dissolve to obtain a precursor solution with a solution concentration of 5wt% - 15wt%.

[0009] During the preparation of the precursor solution, the PEO-b-PVDF block copolymer and other components (inorganic filler, supramolecular monomer, dilithium salt system) mainly undergo physical interactions (such as dissolution, dispersion, hydrogen bonding, etc.) in the solution. These components do not undergo violent chemical reactions in the solution, but they will affect the conductivity, mechanical properties and electrochemical stability of the membrane through microphase separation, network structure formation, ion coordination, etc. during the membrane formation process.

[0010] S2. Gradient evaporation film formation: Uniformly coat the precursor solution on the surface of the substrate, and regulate the evaporation rate in three stages in the range of 30°C - 60°C, with a relative humidity of 30% - 70%, to form an electrolyte membrane with a vertically oriented nanochannel structure.

[0011] Specifically, the prepared precursor solution is uniformly coated on the surface of a flat substrate by a casting method or a doctor blade coating method. The substrate is a glass plate, a stainless steel plate or a polyimide film (PI film), etc. The thickness of the coated film is controlled between 50 and 200μm according to the final application requirements.

[0012] S3. Hot pressing crosslinking treatment: Place the electrolyte membrane formed by gradient evaporation in a hot press, and maintain it for a period of time under the hot pressing conditions of 100°C - 150°C and 2MPa - 10Mpa. Use the anhydride group in the crosslinking agent to undergo a ring-opening crosslinking reaction with the hydroxyl group and ether oxygen group in the block copolymer matrix, and control the crosslinking density to be 0.5 - 3mol / m 3 , and finally obtain a polymer solid electrolyte membrane with a multi-scale synergistic structure.

[0013] The styrene maleic anhydride copolymer SMA itself has a random copolymer structure, with a C = C double bond (styrene part) and a cyclic anhydride group (maleic anhydride part). Under the action of heating and compression, the anhydride group of the maleic anhydride part is very easy to undergo an esterification or ring-opening reaction with the hydroxyl group (PEO segment) in the polymer chain, the amino group (possibly from the supramolecular monomer) or the hydroxyl functional group on the surface of the filler to form a covalent bond crosslinking network.

[0014] At 100 - 150 °C, the anhydride groups of SMA react with the ether oxygen or trace hydroxyl groups of the PEO segments, as well as the residual hydroxyl groups on the surface of the inorganic filler, to form an ester bond structure; meanwhile, free radical crosslinking of the double bonds in SMA may occur, especially in the presence of residual initiators in the system, which can trigger self-crosslinking or covalent bonding. Eventually, a crosslinked network of polymer chain - ester bond - SMA - polymer chain is formed, enhancing the mechanical strength, dimensional stability, and thermal stability of the membrane.

[0015] Preferably, the block copolymer is a polyethylene oxide - polyvinylidene fluoride block copolymer PEO - b - PVDF, where the molecular weight of the PEO segment is 500k - 800k, the molecular weight of the PVDF segment is 200k - 400k, and the mass ratio of the blocks is (3:7) - (7:3).

[0016] Preferably, the supramolecular monomer is a fluorinated aromatic compound with the chemical formula C6H4C6F5COOH, and the addition amount is 0.1% - 5% of the mass of the matrix.

[0017] Preferably, the inorganic filler is LLZO nanowires grafted with ionic liquid groups on the surface, with the chemical formula Li7La3Zr2O 12 , the diameter of the nanowires is 20nm - 100nm, the aspect ratio is ≥15, and the filling amount is 5wt% - 30wt% of the total mass of the electrolyte membrane.

[0018] Preferably, the lithium salt system includes a double lithium salt of LiTFSI and LiDFOB, with a molar ratio of 2:1 - 4:1, a total concentration of 0.5mol / L - 2.5mol / L, and further adding an auxiliary additive lithium fluoride LiF or lithium sulfide Li2S, and the content of the auxiliary additive is 2% - 10% of the total mass of the lithium salts.

[0019] Preferably, the surface modification groups of the LLZO nanowires are selected from: 1 - butyl - 3 - methylimidazolium bis(trifluoromethylsulfonyl)imide salt, methoxypolyethylene glycol phosphate mPEG - PO3, perfluorooctyltriethoxysilane FOTS.

[0020] Preferably, the step of forming a film by gradient volatilization includes:

[0021] The first stage: maintain at 30 °C - 40 °C and 50% - 60% relative humidity for 2 - 3h, and the solvent evaporation rate is 35% - 55%;

[0022] Control the slow evaporation of the solvent to promote the initial microphase separation of the PEO and PVDF segments, and the slow migration of the LLZO nanowires and the supramolecular monomer to the appropriate regions, while preventing the collapse of the pores.

[0023] In the initial stage when coated on the substrate and starting to volatilize, the segments of the PEO-b-PVDF block copolymer in the solution are still in a randomly coiled and swollen state. With slow evaporation in the first stage (low temperature and high humidity), due to poor compatibility between the PEO segments and the PVDF segments, thermodynamically driven microphase separation occurs, and the prototype of a biphasic network of continuous PEO ion channel phase + PVDF reinforcing phase begins to assemble.

[0024] Due to the differences in size and interfacial energy, inorganic filler LLZO nanowires will gradually migrate and tend to align vertically during the volatilization process in a solution environment with gradually increasing concentration (driven by the solution concentration gradient and surface tension). Especially for surface-functionalized fillers (grafted with ionic liquid groups), they will be more inclined to "embed" into the voids of the polymer chain network during volatilization and form hydrogen bonds or van der Waals force coupling with the polymer, promoting dispersion stability.

[0025] During the process of decreasing solvent concentration, fluorinated aromatic compounds (supramolecular monomers) will gradually self-assemble spontaneously and embed into the polymer backbone through hydrogen bonding and self-assembly to form a supramolecular network, enhancing the interfacial stability of the membrane. This process proceeds synchronously with volatilization and belongs to a concentration-induced self-assembly (CISA) effect.

[0026] The second stage: Maintain for 1 - 1.5 h at 45°C - 55°C and 30% - 45% relative humidity, with a solvent volatilization rate of 65% - 85%;

[0027] Increase the solvent volatilization rate, promote the flow of PEO segments, assist the vertical ordered distribution of inorganic fillers in the membrane, and initially form vertical ion conduction channels.

[0028] The third stage: Maintain at 55°C - 65°C and 15% - 25% relative humidity for 0.5 h until the solvent completely volatilizes;

[0029] Completely cure the membrane, lock the vertically oriented nanostructure, ensure the formation of continuous channels and remove residual solvents.

[0030] In the second stage (medium temperature and medium humidity), the solvent volatilization rate accelerates, the concentration in the solution increases sharply, the spatial freedom between polymer chains and nano-fillers shrinks, promoting the spontaneous alignment of nano-fillers and PEO segments in the vertical direction. Finally, this alignment mode is completely locked in the third stage (high temperature and low humidity), forming vertically oriented ion conduction channels.

[0031] During the solvent volatilization process, Li+ ions in the solution will actively form a stable coordination complex structure (Li+-O coordination) with the ether oxygen on the PEO chain. When the membrane is cured, this ionic coordination network is "frozen" and becomes the core of the ion conduction path.

[0032] Preferably, the cross-linking agent is styrene maleic anhydride copolymer, and the addition amount of the styrene-maleic anhydride copolymer is 1% to 10% of the mass of the block copolymer.

[0033] A multi-scale synergistic structure polymer solid electrolyte material is prepared by the aforementioned method.

[0034] Compared with the prior art, the advantages of the present invention are as follows:

[0035] 1. After the surface functionalization of the LLZO nanowires in the membrane, they have good dispersibility and interfacial compatibility in the polymer matrix, enhancing the mechanical strength of the membrane.

[0036] 2. Through the thermocompression cross-linking reaction, the SMA copolymer forms a stable cross-linked network in the membrane, which not only improves the dimensional stability and puncture resistance of the membrane, but also significantly extends the cycle life of the electrolyte membrane.

[0037] 3. By introducing supramolecular monomers, a hydrogen bond network is formed, enhancing the stability of the electrolyte-electrode interface, preventing the growth of lithium dendrites and the phenomenon of interface instability, and improving the safety and efficiency of the battery. Specific embodiments

[0038] The technical solutions of the present invention will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments.

[0039] Example 1

[0040] Preparation of a multi-scale synergistic structure polymer solid electrolyte:

[0041] S1. Preparation of the precursor solution:

[0042] Take 8 grams of PEO-b-PVDF block copolymer (the molecular weight of the PEO segment is 600,000, the molecular weight of the PVDF segment is 300,000, and the block mass ratio is 4:6), and add 2 grams of 1,4-difluorobenzoic acid (C6H4C6F5COOH) as a supramolecular filler. Then add 3 grams of LLZO nanowires (diameter of 50 nm, aspect ratio ≥ 15) grafted with 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([BMIM][TFSI]), mix with 1.5 grams of LiTFSI, 0.75 grams of LiDFOB, and 0.05 g of LiF, and then add 0.8 g of styrene-maleic anhydride copolymer. All components are dissolved in 30 ml of a DMF / acetone (volume ratio 3:1) mixed solvent, and stirred evenly to obtain a 5 wt% precursor solution.

[0043] S2. Gradient evaporation to form a film:

[0044] The precursor solution was uniformly coated on a polyimide film substrate with a coating thickness of 100 μm.

[0045] Then, the coated substrate was placed in a constant temperature and humidity chamber with controllable temperature and humidity for gradient volatilization to form a film:

[0046] First stage: 35 °C, relative humidity 60%, maintained for 2 hours, solvent evaporation rate 40% - 50%;

[0047] Second stage: 50 °C, relative humidity 40%, maintained for 1 hour, solvent evaporation rate 70% - 80%;

[0048] Third stage: 60 °C, relative humidity 20%, maintained for 0.5 hours until the solvent was completely evaporated, forming an electrolyte membrane with vertically oriented nanochannels.

[0049] S3. Hot pressing crosslinking treatment:

[0050] The electrolyte membrane after gradient volatilization forming was placed in a hot press, and hot pressed for 30 minutes under the hot pressing conditions of 100 °C and 4 MPa, triggering a ring-opening crosslinking reaction between the anhydride groups in the styrene - maleic anhydride copolymer (SMA) and the hydroxyl and ether oxygen groups in the PEO - b - PVDF matrix, with a crosslinking density of 1.5 mol / m 3 , and finally obtaining a polymer solid electrolyte membrane with a multi-scale synergistic structure.

[0051] Example 2,

[0052] Preparation of a polymer solid electrolyte with a multi-scale synergistic structure:

[0053] S1. Preparation of the precursor solution:

[0054] 6 g of PEO - b - PVDF block copolymer (the molecular weight of the PEO segment is 500,000, the molecular weight of the PVDF segment is 250,000, and the block mass ratio is 5:5) was taken, and 1.5 g of 4-(pentafluorophenyl)benzoic acid (C6H4C6F5COOH) was added as a supramolecular monomer. Then 2.5 g of LLZO nanowires grafted with 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide on the surface (diameter 40 nm, aspect ratio ≥ 12) was added, mixed with 1.2 g of LiTFSI, 0.6 g of LiDFOB, and 0.1 g of LiF, and then 1 g of styrene - maleic anhydride copolymer was added. All components were dissolved in 35 ml of a DMF / acetone (volume ratio 4:1) mixed solvent, and stirred evenly to obtain a 7 wt% precursor solution.

[0055] S2. Gradient volatilization to form a film:

[0056] The precursor solution was uniformly coated on a polyimide film substrate with a coating thickness of 120 μm.

[0057] Then place the coated substrate in a constant temperature and humidity chamber with controllable temperature and humidity for gradient volatilization to form a film:

[0058] The first stage: 40 °C, relative humidity 55%, maintained for 2.5 hours, solvent evaporation rate 45% - 55%;

[0059] The second stage: 55 °C, relative humidity 45%, maintained for 1 hour, solvent evaporation rate 75% - 85%;

[0060] The third stage: 65 °C, relative humidity 18%, maintained for 0.5 hours until the solvent completely evaporates, forming an electrolyte membrane with vertically oriented nanochannels.

[0061] S3. Hot pressing crosslinking treatment:

[0062] Place the electrolyte membrane formed by gradient volatilization in a hot press and conduct hot pressing for 25 minutes under the hot pressing conditions of 120 °C and 5 MPa, triggering a ring-opening crosslinking reaction between the anhydride groups in the styrene-maleic anhydride copolymer and the hydroxyl and ether oxygen groups in the PEO-b-PVDF matrix, with a crosslinking density of 2.0 mol / m 3 , and finally obtain a polymer solid electrolyte membrane with a multi-scale synergistic structure.

[0063] Example 3:

[0064] Preparation of a polymer solid electrolyte with a multi-scale synergistic structure:

[0065] S1. Preparation of the precursor solution:

[0066] Take 10 g of PEO-b-PVDF block copolymer (the molecular weight of the PEO segment is 700,000, the molecular weight of the PVDF segment is 350,000, and the block mass ratio is 6:4), and add 3 g of 5-(trifluoromethyl)benzoic acid (C6H4C6F5COOH) as a supramolecular monomer. Then add 4 g of LLZO nanowires grafted with 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt (diameter 70 nm, aspect ratio ≥ 20), mix with 2.0 g of LiTFSI, 1.0 g of LiDFOB, and 0.1 g of LiF, and then add 1.2 g of styrene-maleic anhydride copolymer. All components are dissolved in 50 ml of a DMF / acetone (volume ratio 2:1) mixed solvent, stirred evenly, and a 10 wt% precursor solution is obtained.

[0067] S2. Gradient volatilization to form a film:

[0068] Evenly coat the precursor solution on a polyimide film substrate with a coating thickness of 150 μm.

[0069] Then place the coated substrate in a thermo-hygrostat with controllable temperature and humidity for gradient volatilization to form a film:

[0070] The first stage: 30 °C, relative humidity 50%, maintained for 3 hours, solvent evaporation rate 35% - 45%;

[0071] The second stage: 45 °C, relative humidity 30%, maintained for 1.5 hours, solvent evaporation rate 65% - 75%;

[0072] The third stage: 55 °C, relative humidity 15%, maintained for 0.5 hours until the solvent is completely evaporated, forming an electrolyte membrane with vertically oriented nanochannels.

[0073] S3. Hot pressing crosslinking treatment:

[0074] Place the electrolyte membrane formed by gradient volatilization in a hot press, and conduct hot pressing for 40 minutes under the hot pressing conditions of 110 °C and 6 MPa, triggering a ring-opening crosslinking reaction between the anhydride groups in the styrene-maleic anhydride copolymer and the hydroxyl and ether oxygen groups in the PEO-b-PVDF matrix, with a crosslinking density of 2.5 mol / m 3 , and finally obtain a polymer solid electrolyte membrane with a multi-scale synergistic structure.

[0075] Example 4:

[0076] Preparation of a polymer solid electrolyte with a multi-scale synergistic structure:

[0077] S1. Preparation of the precursor solution:

[0078] Take 7 grams of PEO-b-PVDF block copolymer (the molecular weight of the PEO segment is 550,000, the molecular weight of the PVDF segment is 280,000, and the block mass ratio is 5:5), and add 2.5 grams of 4-fluorobenzoic acid (C6H4C6F5COOH) as a supramolecular monomer. Then add 3.5 grams of LLZO nanowires grafted with 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt (diameter 60 nm, aspect ratio ≥ 18), mix with 1.8 grams of LiTFSI, 0.9 grams of LiDFOB, and 0.06 g of LiF, and then add 1 gram of styrene-maleic anhydride copolymer. All components are dissolved in 40 ml of a DMF / acetone (volume ratio 3:1) mixed solvent, and stirred evenly to obtain a 6 wt% precursor solution.

[0079] S2. Gradient volatilization to form a film:

[0080] Uniformly coat the precursor solution on a polyimide film substrate with a coating thickness of 110 μm.

[0081] Then place the coated substrate in a thermo-hygrostat with controllable temperature and humidity for gradient volatilization to form a film:

[0082] The first stage: 38 °C, relative humidity 55%, maintained for 2 hours, solvent evaporation rate 45% - 55%;

[0083] The second stage: 48 °C, relative humidity 35%, maintained for 1 hour, solvent evaporation rate 75% - 85%;

[0084] The third stage: 58 °C, relative humidity 25%, maintained for 0.5 hour until the solvent is completely evaporated, forming an electrolyte membrane with vertically oriented nanochannels.

[0085] S3. Hot pressing and crosslinking treatment:

[0086] Place the electrolyte membrane after gradient evaporation forming in a hot press, and hot press for 35 minutes under the hot pressing conditions of 125 °C and 4.5 MPa, triggering a ring-opening crosslinking reaction between the anhydride groups in the styrene - maleic anhydride copolymer and the hydroxyl and ether oxygen groups in the PEO - b - PVDF matrix. The crosslinking density is 1.8 mol / m 3 , and finally obtain a polymer solid electrolyte membrane with a multi-scale synergistic structure.

[0087] Comparative Example 1:

[0088] Use a PEO-based electrolyte membrane as the comparative example.

[0089]

[0090] The comparative experiment (traditional PEO-based electrolyte membrane) shows that its ionic conductivity is 5×10 -6 S / cm, while the ionic conductivity of the electrolyte membranes in the examples is generally improved. Especially for Example 1 (1.1×10 - 3 S / cm), far exceeding that of the traditional PEO-based electrolyte membrane, indicating that through the optimization of the block copolymer, inorganic filler, and dual-lithium salt system, the conductivity can be significantly improved, enhancing the fast charging ability of the battery.

[0091] The lithium ion transference number of the traditional PEO-based membrane is relatively low (~0.2), while the transference numbers in the examples are generally greater than 0.5. Especially for Example 3 (0.57), indicating that through structural optimization and material selection (such as the introduction of LLZO nanowires and supramolecular monomers), the migration ability of lithium ions in the electrolyte membrane can be significantly improved, contributing to the improvement of the battery's charging rate and energy density.

[0092] The elongation at break of the traditional PEO-based electrolyte membrane is relatively low (50%), while the elongation at break of the electrolyte membranes in the examples is significantly improved. Especially for Example 1 (180%), showing that the membrane has good flexibility and can withstand large mechanical deformations without rupture. This is crucial for the cycle stability of the battery.

[0093] The electrochemical stability window of the traditional PEO-based membrane is less than 4.5 V, while the stability windows of the electrolyte membranes in the examples are generally greater than 5.0 V, especially in Example 2 (5.3 V). This indicates that through the optimization of the dual lithium salt system and inorganic fillers, the present invention has greatly improved the stability of the electrolyte membrane under high voltage and can meet the requirements of high energy density batteries.

[0094] The capacity retention rate of the comparative experiment dropped to 70% after 200 cycles, while the capacity retention rates in the examples were significantly improved after 300 cycles, especially in Example 1 (95%). This shows that through the hot pressing cross-linking treatment and the design of the multi-scale synergistic structure, the stability and cycle life of the electrolyte membrane have been greatly improved.

[0095] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A preparation method of a multi-scale cooperative structure polymer solid electrolyte, characterized in that, It includes the following steps: S1. Preparation of precursor solution: Add block copolymer, supramolecular monomer, inorganic filler, lithium salt system and crosslinking agent into the DMF / acetone mixed solvent in proportion, stir and dissolve to obtain a precursor solution with a solution concentration of 5wt% - 15wt%. S2. Gradient evaporation film formation: Uniformly coat the precursor solution on the surface of the substrate, control the evaporation rate in three stages in the range of 30°C - 60°C, and the relative humidity is 30% - 70% to form an electrolyte membrane with a vertically oriented nanochannel structure. S3. Hot pressing crosslinking treatment: Place the electrolyte membrane after gradient volatilization molding in a hot press, and maintain it for a period of time under hot pressing conditions of 100°C to 150°C and 2 MPa to 10 Mpa. Use the anhydride groups in the crosslinking agent to undergo ring-opening crosslinking reactions with the hydroxyl groups and ether oxygen groups in the block copolymer matrix, and control the crosslinking density to be 0.5 to 3 mol / m 3 , and finally obtain a polymer solid electrolyte membrane with a multi-scale synergistic structure.

2. The preparation method according to claim 1, wherein, The block copolymer is a polyethylene oxide - polyvinylidene fluoride block copolymer PEO - b - PVDF, where the molecular weight of the PEO segment is 500k - 800k, the molecular weight of the PVDF segment is 200k - 400k, and the block mass ratio is (3:7) - (7:3).

3. The preparation method according to claim 1, characterized in that, The supramolecular monomer is a fluorinated aromatic compound with the chemical formula C6H4C6F5COOH, and the addition amount is 0.1% - 5% of the matrix mass.

4. The preparation method according to claim 1, wherein The inorganic filler is LLZO nanowires with surface-grafted ionic liquid groups, and the chemical formula is Li7La3Zr2O 12 , the diameter of the nanowires is 20 nm to 100 nm, the aspect ratio is ≥15, and the filling amount is 5 wt% to 30 wt% of the total mass of the electrolyte membrane.

5. The preparation method according to claim 1, characterized in that, The lithium salt system includes a double lithium salt of LiTFSI and LiDFOB, with a molar ratio of 2:1 - 4:1, a total concentration of 0.5mol / L - 2.5mol / L, and further add an auxiliary additive lithium fluoride LiF or lithium sulfide Li2S, and the content of the auxiliary additive is 2% - 10% of the total lithium salt mass.

6. The preparation method according to claim 1, wherein The surface modification groups of the LLZO nanowires are selected from: 1 - butyl - 3 - methylimidazolium bis(trifluoromethylsulfonyl)imide, methoxypolyethylene glycol phosphate mPEG - PO3, perfluorooctyltriethoxysilane FOTS.

7. The preparation method according to claim 1, characterized in that, The gradient evaporation film formation step includes: The first stage: Maintain at 30°C - 40°C and 50% - 60% relative humidity for 2 - 3h, and the solvent evaporation rate is 35% - 55%. The second stage: Maintain at 45°C - 55°C and 30% - 45% relative humidity for 1 - 1.5h, and the solvent evaporation rate is 65% - 85%. The third stage: Maintain at 55°C - 65°C and 15% - 25% relative humidity for 0.5h until the solvent is completely evaporated.

8. The preparation method according to claim 1, characterized in that The crosslinking agent is a styrene - maleic anhydride copolymer, and the addition amount of the styrene - maleic anhydride copolymer is 1% - 10% of the block copolymer mass.

9. A multi-scale collaborative structure polymer solid electrolyte material, characterized in that Prepared by the method described in any one of claims 1 - 8.

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