CN116284915A

CN116284915A - Ion-dipole mediated elastomer electrolyte film and preparation method and application thereof

Info

Publication number: CN116284915A
Application number: CN202211093838.0A
Authority: CN
Inventors: 陈本
Original assignee: Individual
Current assignee: Xiamen Wuren Juneng Enterprise Management Partnership (Limited Partnership)
Priority date: 2022-09-08
Filing date: 2022-09-08
Publication date: 2023-06-23

Abstract

The invention relates to an ion-dipole mediated elastomer electrolyte film, a preparation method and application thereof, wherein the elastomer electrolyte film takes unsaturated ester as a rigid main chain, and sulfonyl groups are grafted on the rigid main chainVinyl monomers of trifluoromethanesulfonyl) imide groups to form novel copolymers, low co-solvents are added to form-c≡n ⁺ The ionic dipole interaction of (2) improves the ionic conductivity, so that the polymer has excellent low-temperature and high-temperature performances. The solid electrolyte film of the elastomer polymer with ion-dipole mediation, which is obtained by an in-situ solidification method, has good contact with an electrode and shows good electrochemical stability with metallic lithium; the ion-dipole mediated elastomer electrolyte film has excellent ion migration number, ion conductivity and wide electrochemical window, and can effectively promote uniform deposition of lithium in the long cycle process of the battery, thereby improving the low-temperature cycle performance and the safety performance of the battery.

Description

Ion-dipole mediated elastomer electrolyte film and preparation method and application thereof

Technical Field

The invention relates to the field of power batteries, in particular to an ion-dipole mediated elastomer electrolyte film, a preparation method and application thereof.

Background

With the development of energy storage batteries, lithium ion batteries with high energy density, high cycle stability, high safety and capability of operating normally in a wide temperature range are increasingly demanded, and particularly, the 3C products and new energy automobiles are receiving a wide attention. At present, most of lithium ion batteries adopt organic liquid electrolyte such as ethers and carbonates as electrolyte, and the liquid electrolyte has obvious advantages and disadvantages such as high room temperature ion conductivity, good electrode/electrolyte interface wettability and contact property, but the liquid organic electrolyte has low ion migration number, obvious concentration polarization, strong fluidity, easy liquid leakage, easy volatilization, easy combustion and even explosion and other safety problems. In addition, during cycling of the battery, lithium dendrite formation can also puncture the separator, causing the battery to short circuit and fire. The adoption of solid electrolyte instead of traditional organic liquid electrolyte can effectively solve the problems. In general, solid-state electrolytes are generally superior to liquid electrolytes in terms of physical/chemical stability, electrochemical stability, and mechanical properties. Therefore, the use of the solid electrolyte can fundamentally eliminate potential safety hazards in theory. Meanwhile, the electrochemical stability window of part of solid electrolyte is far better than that of organic electrolyte, so that the solid electrolyte can be used for high-voltage positive electrode materials, and the energy density of a lithium ion battery is further improved. In addition, solid state electrolytes are also capable of achieving high lithium ion transport coefficients, thereby promoting more uniform lithium metal deposition. In addition to the above advantages, it is important that the solid electrolyte has the advantage of normal operation over a wide temperature range.

The main solid electrolytes currently under development are mainly of three types: polymers, inorganic ceramics, organic-inorganic composites. Among these, the polymer electrolyte is suitable for mass production because of its advantages of excellent interfacial contact, good ductility, and the like. Patent publication No. CN113013490A discloses an ultralow temperature polymer battery and a manufacturing process, long-chain organic alcohol is added into electrolyte, so that electrolyte solute presents discontinuous phase, namely disperse phase distribution at a low temperature of minus 50 ℃, thereby enhancing ion movement speed, and when ions migrate between positive and negative electrodes, the solute disperse phase is recombined to form new ordered arrangement, and charge carrying drift is carried in a solvent, so that the service performance of the polymer battery is improved; and pore-forming processing is carried out on the polymer coated on the surfaces of the diaphragm and the negative electrode plate, so that the ion movement speed is enhanced, and the service performance of the ultralow-temperature polymer battery is further enhanced. However, the invention has a large amount of organic electrolyte, the mechanical property is poor, and the safety is not guaranteed.

Ion-dipole interactions are prevalent in the binder and can effectively enhance electron transport of the binder. However, the application of the polymer electrolyte in the all-solid-state elastomer is relatively small at present because most of the ion-dipole polymers have poor film forming property and are difficult to be applied to large-scale lithium metal batteries. The patent publication No. CN 112500818B proposes to provide an adhesive, a preparation method thereof and an adhesive tape, wherein the adhesive is an adhesive system constructed by relying on ionic liquid, and the cohesive force of the adhesive can be improved by utilizing the ion dipole interaction between a polymer chain and the ionic liquid or between the chains, and meanwhile, the adhesive force with different base materials, especially the adhesive performance of a low-surface-energy base material, is greatly improved by introducing the ionic liquid; has high transparency and better water resistance and weather resistance. Patent publication number CN 110358002A proposes an ionic gel and ionic gel based friction nano generator, wherein the ionic gel network is composed of the interaction between polymers and the interaction between polymer and ionic liquid, has no pull rope performance, and has poor conductivity.

Disclosure of Invention

The invention provides an ion-dipole mediated elastomer electrolyte film and a preparation method and application thereof, which aim at solving the problems that the existing polymer solid electrolyte cannot circulate under the low temperature condition, the ion conductivity at room temperature is insufficient, the ion migration number at the ion conductivity at the room temperature is unstable and inflammable and the like by combining a film carrier with good film forming property, and an unsaturated ester grafted vinyl monomer with sulfonyl- (trifluoromethanesulfonyl) imide group forms a polymer skeleton, and meanwhile, a eutectic agent has certain flame retardant property, and the three components of the polymer skeleton are combined together to form a polymer electrolyte film with ion-dipole interaction.

The ion-dipole mediated elastomer electrolyte film is formed by reaction and solidification of a precursor solution under the ultraviolet irradiation condition, wherein the precursor solution consists of an initiator, unsaturated ester, low co-solvent, a film carrier, vinyl monomer of sulfonyl- (trifluoromethanesulfonyl) imide group and alkali metal lithium salt. Wherein, the sulfonyl- (trifluoromethanesulfonyl) imide group vinyl monomer is self-made by the invention, and the structural formula is as follows:

The R group in formula (1) comprises a vinyl unit and X is independently selected from Li, na, K, preferably Li.

In the preparation method of the electrolyte film, the 4-styrenesulfonyl (trifluoromethyl sulfonyl) imine in the K form is obtained in the step (2), and is converted into the 4-styrenesulfonyl (trifluoromethyl sulfonyl) imine in the Li form in the step (3), so that the lithium ion capable of freely moving can be provided as a partially low-solvation lithium source.

The initiator and vinyl monomer of sulfonyl- (trifluoromethanesulfonyl) imide group are sufficiently dissolved by the unsaturated ester monomer, and the film carrier and lithium salt form a uniform solution in a solvent; the unsaturated ester monomer and the vinyl monomer of sulfonyl- (trifluoromethanesulfonyl) imide group are copolymerized under the action of an initiator. The film finally obtained by volatilizing the redundant solvent is an elastomer electrolyte self-supporting film, and has excellent ion transmission capability and oxidation resistance.

The invention consists of dipole-dipole and ion-dipole interactionsThe ion gel network exhibits high stretchability and ionic conductivity, wherein dipole-dipole action refers to the linking action of the cyano-containing small molecule low co-solvent with carbonyl groups in the polymer to form-c≡n..o=c-, and ion-dipole action refers to the linking action of the cyano-containing small molecule low co-solvent with free lithium ions to form-c≡n..li ⁺ Is connected with the connecting function of the connecting rod.

Patent publication No. CN 107879978B discloses an ionic liquid compound, a preparation method thereof, an ionic liquid polymer and a polymer solid electrolyte containing the ionic liquid compound and the ionic liquid polymer, wherein the anion centers of the ionic liquid compound and the ionic liquid polymer are perfluorinated sulfimide ions with weaker coordination ability, so that the Li of the anion center is reduced ⁺ To improve the conductivity and Li of a polymer solid electrolyte containing the ionic liquid polymer ⁺ Migration number. However, the side chain of the ionic liquid prepared by the method does not have free Li ions, but large cationic groups, and the side chain of the polyionic liquid takes lithium ions as cationic groups, so that the side chain of the polyionic liquid can be free to form free movable lithium ions due to ion-dipole interaction, and the ion migration number is further improved, which is a great innovation point and a bright point of the polyionic liquid.

On the other hand, the ionic liquid exists in the form of polymer branched chains in the invention, and most of the ionic liquid exists in the form of additives in the prior patent. Specifically, in the invention, through reasonable molecular design, vinyl monomer side chains with sulfonyl- (trifluoromethanesulfonyl) imide groups are skillfully grafted in a polymer main chain, and the multi-ion structure is similar to lithium bistrifluoromethanesulfonimide, has great delocalization on negative charge, and enhances Li ⁺ And improves the migration capacity of lithium ions. At the same time, small amounts of small molecule, low co-solvents containing cyano groups can be added to the precursor liquid to form-c≡n ⁺ In addition to further improving ion conductivity, the polymer electrolyte can still keep the amorphous region dominant at low temperature, so that Li ions can still be rapidly conducted in the amorphous region at low temperature. To sum up the invention and the prior artThere are obvious application fields, polymer structures and mechanisms of the technology.

The invention can effectively improve the ion conductivity, the ion migration number and the high-low temperature performance of the solid electrolyte by limiting the composition of the polymer in the solid electrolyte, thereby meeting the requirements of the polymer in a wide temperature range. Aiming at the problems of increased cost and pollution caused by using solvents in the preparation process of the existing solid polymer electrolyte, low ionic conductivity at room temperature, poor low-temperature performance, poor high-temperature mechanical performance, interface side reaction and the like of the existing solid polymer electrolyte, the invention adopts a rigid chain segment to form a polymer electrolyte skeleton, and grafts vinyl monomers with sulfonyl- (trifluoromethanesulfonyl) imide groups, wherein the polyion structure is similar to that of lithium bistrifluoromethanesulfonimide, has great delocalization on negative charge, enhances the dissociation of Li+ and improves the migration capability of lithium ions. Meanwhile, a small amount of small molecule low cosolvent containing cyano groups is added into precursor liquid to form ion-dipole interaction of-C.ident.N. Li < + >, so that ion conductivity is further improved, besides, the polymer electrolyte can still keep an amorphous region to be dominant at low temperature, li ions can still be rapidly conducted in the amorphous region at low temperature, and the elastomer all-solid electrolyte membrane is prepared in one step by adopting a simple process without solvent photo-curing, so that interface impedance is reduced, and the possibility of gaps at an electrolyte/electrode interface is avoided.

The invention also provides a battery comprising the ion-dipole mediated elastomer electrolyte film as an electrolyte to form a lithium metal battery. Preferably, the battery is a lithium cobalt oxide-lithium metal battery, a lithium iron phosphate-lithium metal battery or a lithium-rich positive electrode-lithium metal battery, and the operating temperature of the battery ranges from-20 ℃ to 100 ℃. Since the above electrolyte has good ion transport ability and ion-dipole interaction, the lithium metal battery has excellent cycle stability and low temperature performance.

The specific scheme is as follows:

a method for preparing an ion-dipole mediated elastomeric electrolyte membrane comprising the steps of:

(1) Mixing oxalyl chloride, N-dimethylformamide and a solvent, stirring to promote Vilsmeier-Haack reaction to form a complex, adding sodium styrenesulfonate into the solution at room temperature under a protective atmosphere when the solution turns yellow, stirring to react, and separating NaCl precipitate by filtration to obtain a solution X;

(2) Mixing triethylamine, trifluoromethyl sulfonamide, 4-dimethylaminopyridine and a solvent, stirring to promote dissolution, and obtaining a trifluoromethyl sulfonamide mixture; cooling the solution X in the step (1) to-5 to 5 ℃, adding the trifluoromethyl sulfonamide mixture into the cooled solution X, stirring and reacting for 10-20 hours, removing the solvent to obtain a brown solid, dissolving the brown solid in methylene dichloride, washing the solution with an alkaline aqueous solution and an acidic aqueous solution, neutralizing an acid monomer generated by the reaction with potassium salt to obtain K-form 4-styrenesulfonyl (trifluoromethyl sulfonyl) imine, uniformly stirring the obtained suspension, filtering and drying to obtain a light yellow solid, and recrystallizing to obtain powder Y;

(3) Mixing the powder Y in the step (2) with lithium salt in a solvent for reaction, and filtering to separate precipitate after the reaction is finished to obtain the Li-form 4-styrenesulfonyl (trifluoromethyl sulfonyl) imine;

(4) Dissolving a film carrier and lithium salt in a solvent to obtain a solution Z;

(5) Mixing an initiator and an unsaturated ester monomer under a protective atmosphere to obtain a solution M;

(6) Uniformly stirring the eutectic agent and the solution M obtained in the step (5) under the protection atmosphere and light-shielding conditions to obtain a solution N;

(7) Adding the Li-form 4-styrenesulfonyl (trifluoromethyl sulfonyl) imine of the step (3) into the solution N obtained in the step (6), and uniformly stirring under the protection atmosphere and light-shielding conditions at 20-35 ℃ to obtain a solution P;

(8) Uniformly stirring the solution P of the step (7) and the solution Z of the step (4) at 20-35 ℃ under the protection atmosphere and the light-shielding condition to obtain a casting solution;

(9) And (3) adding the casting solution obtained in the step (8) into a die, standing the casting solution, performing ultraviolet irradiation treatment, curing, and performing vacuum drying to obtain the ion-dipole-mediated elastomer electrolyte film.

Further, in the step (1), the molar ratio of oxalyl chloride to N, N-dimethylformamide is 3:1-30:1, preferably 13:1 to 24:1; the addition amount of the sodium styrenesulfonate is 1.1-1.2 times of the molar mass of the N, N-dimethylformamide;

Optionally, the molar ratio of triethylamine, trifluoromethylsulfonamide and 4-dimethylaminopyridine in step (2) is from 2 to 3:1 to 2:1 to 2, preferably 2:1:1.5; the solute content of the trifluoromethylsulfonamide mixture is 3-15%, preferably 5-12%.

Further, the addition amount of the lithium salt in the step (3) is 1 to 1.5 times of the molar amount of the powder Y, the reaction temperature is 30 to 150 ℃, preferably 80 to 100 ℃, and the reaction time is 3 to 6 hours;

optionally, the film carrier in the step (4) is one or more of polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, glycidyl ether epoxy resin, glycidyl ester epoxy resin, glycidyl amine epoxy resin, epoxy alkene epoxy resin and derivatives thereof, preferably polyvinylidene fluoride or polyvinylidene fluoride-hexafluoropropylene; preferably, the film carrier is combined with lithium salt in a ratio of 1:0.1 to 1:1 in a mass ratio in a solvent to form a solution Z with a mass content of 10 to 20%.

Further, the initiator in the step (5) is a photoinitiator or a thermal initiator, and the addition amount is 1-5% of the unsaturated ester monomer;

preferably, the photoinitiator is one or more of 2-hydroxy-2-methylpropenoyl ketone, dialkoxyacetophenone, alpha-hydroxyalkyl benzophenone, acylphosphine oxide, diphenyl (2, 4, 6-trimethylbenzoyl) phosphine oxide, and 2-methyl-1- (4-methylthiophenyl) -2-morpholin-1-one;

Preferably, the thermal initiator is one or more of azodiisobutyronitrile, dicumyl peroxide, dibenzoyl peroxide and di-tert-butyl diisopropylbenzene peroxide;

optionally, the unsaturated ester monomer in step (5) is at least one of ethylene carbonate, ethyl 2-cyanoacrylate, polyethylene glycol diacrylate, polyethylene glycol methacrylate, trimethylolpropane triacrylate, butyl acrylate, methyl methacrylate, vinyl acetate, pentaerythritol triacrylate, ethoxylated trimethylolpropane triacrylate, furfuryl alcohol methacrylate, and derivatives thereof.

Further, in the step (6), the low co-solvent is prepared by mixing one or more of urea, methyl urea, N-methylacetamide, succinonitrile and thiourea with lithium salt, preferably, the low co-solvent is prepared by mixing N-methylacetamide or succinonitrile with LiTFSI at a ratio of 10:1 to 1:1 at a temperature of between 40 and 55 ℃;

optionally, in step (6), the low co-solvent is added in an amount of 40-50% of the mass of the solution M;

optionally, in step (7), the mass fraction of the solution P is 5-40%, preferably 10-30%.

Further, the solvent is at least one of anhydrous acetonitrile, acetone, dimethyl sulfoxide, toluene, xylene, cyclohexane, cyclohexanone, pyridine or phenol; the protective atmosphere is nitrogen or at least one of zero group element gases of the periodic table; the ultraviolet irradiation treatment is irradiation for 0.5-3 hours under ultraviolet light with the wavelength of 300-400 nm.

The invention also protects the ion-dipole mediated elastomer electrolyte film prepared by the preparation method of the ion-dipole mediated elastomer electrolyte film.

Further, the polymer number average molecular weight of the ion-dipole mediated elastomer electrolyte membrane is 5000-500000, preferably 10000-45000; the crystallinity of the polymer is 10-50, preferably 20-30; the thermal decomposition temperature is 200-600 ℃, preferably 295-534 ℃; young's modulus of 1-15GPa, preferably 3-11GPa; the solid electrolyte ion migration number is 0.1 to 1.0, preferably 0.4 to 0.7; the electrochemical stability window voltage of the solid electrolyte is 3-6V, preferably 4.2-6V; the polarization voltage of the solid electrolyte half cell is 50-300mV, preferably 100-200mV; the glass transition temperature is-40 to-70 ℃, preferably-50 to 60 ℃; the ionic conductivity at 30℃is 0.3-3mS/cm, preferably 1.2-2mS/cm.

The invention also protects the application of the ion-dipole mediated elastomer electrolyte film in the solid electrolyte material of the lithium metal battery.

The invention also protects a battery comprising the ion-dipole mediated elastomer electrolyte film, preferably the battery is a lithium cobaltate-lithium metal battery, a lithium iron phosphate-lithium metal battery or a lithium-rich positive electrode-lithium metal battery, the battery operating temperature range is-20 ℃ to 100 ℃, more preferably a lithium iron phosphate-lithium metal battery, and the lithium iron phosphate-lithium metal battery is reduced in capacity to 80% of the first discharge capacity after being cycled for 100-600 times at 30 ℃; after cycling 50-300 times at-10 ℃, the capacity decays to 80% of the first discharge capacity.

The beneficial effects are that:

(1) In the invention, the precursor solution consists of unsaturated ester monomer, initiator, low-co-solvent, vinyl monomer with sulfonyl- (trifluoromethanesulfonyl) imide group and lithium salt, and the system has low raw material cost and is favorable for greatly improving the battery performance.

(2) The ion-dipole mediated elastomer electrolyte system provided by the invention depends on a PVDF or PVDF-HFP (polyvinylidene fluoride-hexafluoropropylene) and other film carriers, so that the mechanical properties of the ion-dipole mediated elastomer electrolyte membrane are improved. By means of a trace amount of low co-solvent, not only can the flame retardant effect be achieved, but also an ion-dipole acting donor can be provided. Monomers with unsaturated esters can be polymerized easily by heating or irradiation of light, while the grafted polyionic side chains, like lithium bistrifluoromethanesulfonimide, have a large degree of delocalization on the negative charge, which enhances Li ⁺ And (5) dissociation. Electrolyte system production-c=o..li ⁺ And-c≡n..li ⁺ Is useful for improving ionic conductivity.

On the other hand, the addition of a small amount of low co-solvent can increase the oxidation resistance of the polymer. The polymer electrolyte can exhibit unique single ion conductive behavior due to the ability of lithium ions to migrate from the polymerized grafted side chain-SO ₂ N(-)SO ₂ CF ₃ Efficient dissociation in the group and p-c=o … Li ⁺ and-C.ident.N … Li ⁺ Ion-dipole phaseAccurate adjustment of interactions.

(3) The solid electrolyte provided by the invention has the advantages of optimal component proportion and compatibility, good flexibility, high chemical/electrochemical/thermal stability and basic conditions for large-scale preparation. Compared with PEO-based electrolyte, the ion-dipole mediated all-solid electrolyte provided by the invention has high ion conductivity at room temperature, good thermal stability and interface stability, and simultaneously has excellent low-temperature performance.

(4) The preparation process provided by the invention is simple, does not need curing agent or solvent in the production and processing process, is environment-friendly, and is easy to realize industrial production and commercial application. And because the reaction does not need a solvent, the all-solid-state electrolyte can be used for preparing the all-cell in an in-situ curing mode, and the interface contact between the electrolyte and the electrode is greatly optimized. The electrolyte system without liquid greatly reduces the occurrence of potential safety hazards and accords with future development planning of the battery industry.

Drawings

In order to more clearly illustrate the technical solutions of the present invention, the following brief description will be made on the accompanying drawings, which are given by way of illustration only and not limitation of the present invention.

FIG. 1 is a nuclear magnetic resonance H spectrum of a vinyl monomer having a sulfonyl- (trifluoromethanesulfonyl) imide group prepared in example 1 of the present invention.

FIG. 2 is a thermogravimetric diagram of an ion-dipole mediated elastomer electrolyte prepared according to example 3 of the present invention.

FIG. 3 is an SEM image of an ion-dipole mediated elastomer of adaptive deformation prepared in example 3 of the present invention.

Fig. 4 is a cross-sectional SEM image of a lithium ion battery of example 3 carrying the adaptively deformed elastomeric polymer electrolyte membrane according to the present invention after cycling.

Fig. 5 is a cyclic charge-discharge curve at low temperature of the lithium ion battery of example 3 carrying the ion-dipole-mediated elastomer electrolyte membrane of the present invention.

Detailed Description

The preparation method of the ion-dipole mediated elastomer electrolyte film provided by the invention comprises the following steps:

(3) Mixing powder Y in (2) with lithium salt in solvent to react, and filtering to separate KBF after the reaction ₄ Precipitating to obtain the Li-form 4-styrenesulfonyl (trifluoromethylsulfonyl) imide;

Preferably, the method comprises the following steps: (1) Oxalyl chloride and N, N-dimethylformamide were added to a quantity of anhydrous acetonitrile in varying molar ratios and stirred for 3-8 hours to promote the formation of Vilsmeier-Haack complex. When the solution turned yellow, a certain amount of sodium 4-styrenesulfonate was slowly added to the solution at room temperature under a nitrogen atmosphere. The mixture was stirred for 20 to 40 hours. Separating NaCl precipitate by filtration to obtain a product; (2) Triethylamine, trifluoromethylsulfonamide and 4-dimethylaminopyridine were added in this order to anhydrous acetonitrile. The mixture was stirred for 0.5 to 2.5 hours to completely dissolve all components. The product solution in (1) was cooled to 0 ℃, then the trifluoromethylsulfonamide mixture was slowly added to the solution and left under vigorous magnetic stirring for 10-20 hours. The solvent was removed and the resulting brown solid was dissolved in dichloromethane. The solution was washed with aqueous NaHCO3 and hydrochloric acid. By using excessive K ₂ CO ₃ The acid monomer produced by the neutralization reaction gives 4-styrenesulfonyl (trifluoromethylsulfonyl) imide in the K form. The resulting suspension was stirred for several hours, filtered and dried to give a pale yellow solid. Recrystallizing from water to obtain a final product powder; (3) Reacting the product in the step (2) with lithium salt in anhydrous acetonitrile, continuously reacting for 3-6 hours at low temperature, and separating precipitate by filtration to finally obtain the product Li-form 4-styrenesulfonyl (trifluoromethyl sulfonyl) imine; (4) Dissolving the film carrier and lithium salt in acetonitrile solution in different mass ratios, and fully stirring in an oil bath at 40 ℃ (the rotating speed is 600 r/min) until the film carrier and the lithium salt are completely dissolved; (5) Adding one or more of the initiators into the unsaturated ester monomer, and fully stirring at a rotating speed of 600r/min under the argon atmosphere and under the complete light-shielding condition under the argon atmosphere to enable the unsaturated ester monomer to be completely dissolved; (6) The low co-solvent and the solution obtained in the step (5) are fully stirred at the rotating speed of 600r/min under the condition of complete light shielding under the argon atmosphere according to different volume ratios at room temperature so as to form a uniform solutionThe method comprises the steps of carrying out a first treatment on the surface of the (7) Dissolving the Li-form 4-styrenesulfonyl (trifluoromethyl sulfonyl) imine of the step (3) in the solution of the step (6) according to different mass ratios, and fully stirring at a rotating speed of 600r/min under the complete light-shielding condition at 30 ℃ under the argon atmosphere to form a uniform solution; (8) The solution of (7) and the solution of (4) are fully stirred at the speed of 600r/min under the condition of complete light shielding under the condition of argon atmosphere at the temperature of 30 ℃ according to different volume ratios (1:1; 1:1.5;1:2;1:2.5; 1:3) so as to form a uniform solution; (9) Adding the solution obtained in the step (8) into a die, standing the casting solution, performing ultraviolet irradiation treatment, fully curing, and drying the treated film in a vacuum oven to obtain the ion-dipole-mediated elastomer electrolyte film.

Preferably, the molar ratio of oxalyl chloride to N, N-dimethylformamide in step (1) is 3.3:1, a step of; 13.3:1, a step of; 23.3:1, a step of; 30:1, a step of; dissolved in 50ml of anhydrous acetonitrile. Of particular note is that due to c=c and-SOCl ₂ The high reactivity of the groups does not remove acetonitrile to avoid adverse effects caused by too fast a reaction rate.

Preferably, in the step (2), the addition amount of the triethylamine, the trifluoromethyl sulfonamide and the 4-dimethylaminopyridine accounts for 5-12% of the mass of the anhydrous acetonitrile, wherein the molar ratio of the triethylamine to the trifluoromethyl sulfonamide to the 4-dimethylaminopyridine is 2:1:1.5.

Preferably, the lithium salt added in the step (3) is 1 time of the molar amount of the product in the step (2).

Preferably, the film carrier in the step (4) is one or more of polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, glycidyl ether epoxy resin, glycidyl ester epoxy resin, glycidyl amine epoxy resin, epoxy alkene epoxy resin and derivatives thereof. Preferably PVDF, PVDF-HFP and with one or more of the lithium salts mentioned at 1:0.2;1:0.4;1:0.6;1:0.8;1:1 in the mass ratio of the acetonitrile to form a uniform solution of 10 to 20 percent.

Preferably, the initiator in the step (5) is added in an amount of 1 to 5% of the unsaturated ester monomer.

Preferably, the unsaturated ester monomer in step (5) is one or more of ethylene carbonate (VEC), vinylene Carbonate (VC), ethyl 2-Cyanoacrylate (CA), polyethylene glycol diacrylate (PEGDA), polyethylene glycol methacrylate (PEGMAM), trimethylolpropane triacrylate (TMPTA), butyl Acrylate (BA), methyl Methacrylate (MMA), vinyl Acetate (VA), pentaerythritol triacrylate (PETA), ethoxylated trimethylolpropane triacrylate (ETPTA), and furfuryl methacrylate alcohol ester (FM), and derivatives thereof.

Preferably, the low co-solvent in the step (6) is prepared by mixing one or more of urea, methyl urea, N-methylacetamide, succinonitrile and thiourea with a lithium salt. Preferably, the low co-solvent is N-methylacetamide, and succinonitrile and lithium salt are respectively mixed according to the following ratio of 1:1, a step of; 1:2;1:4, a step of; 1: a molar ratio of 10 forms a liquid low co-flux at 50 ℃. The lithium salt is one or more of the following: liAsF ₆ 、LiDFOB、LiBOB、LiFSI、LiTFSI、LiN(C ₂ F ₅ SO ₂ ) ₂ 、LiPF ₆ 、LiN(CF ₃ SO ₂ )(C ₄ F ₉ SO ₂ )、LiTDI、LiBF ₄ 、LiClO ₄ LiTFSI is preferred.

Preferably, the Li-form 4-styrenesulfonyl (trifluoromethylsulfonyl) imide in step (7) is dissolved in the solution of step (6) to form a uniform solution having a mass fraction of 5-40%.

Preferably, the lithium salt in the step (3) and the step (4) is one or more of the following: liAsF ₆ 、LiDFOB、LiBOB、LiFSI、LiTFSI、LiN(C ₂ F ₅ SO ₂ ) ₂ 、LiPF ₆ 、LiN(CF ₃ SO ₂ )(C ₄ F ₉ SO ₂ )、LiTDI、LiBF ₄ 、LiClO ₄ 。

Preferred embodiments of the present invention will be described in more detail below. While the preferred embodiments of the present invention are described below, it should be understood that the present invention may be embodied in various forms and should not be limited to the embodiments set forth herein. The specific techniques or conditions are not identified in the examples and are performed according to techniques or conditions described in the literature in this field or according to the product specifications. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention. In the examples below, "%" refers to weight percent, unless explicitly stated otherwise.

The test methods used below included:

1. the method for relevant characterization of the polymers in table 2 is as follows:

before the number average molecular weight and crystallinity of the polymer are tested, the polymer is treated in dimethyl sulfoxide for 24 hours at 80 ℃, supernatant is obtained after suction filtration, then column chromatography separation is carried out on the supernatant to obtain the polymer, and then the number average molecular weight and crystallinity of the polymer obtained after separation are tested. The polymer number average molecular weight and crystallinity were measured as follows:

Polymer number average molecular weight test: and dissolving the polymer in a solvent to form a uniform liquid system, carrying out suction filtration on an organic film, detecting a sample by a Shimadzu GPC-20A gel chromatograph, and collecting molecular weight information.

Polymer crystallinity test: the polymer was ground into powder and the crystallinity of the polymer was measured using an Shimadzu XRD-7000X-ray diffractometer with the sample placed horizontally using a theta/theta scanning mode. The crystallinity of the polymer, based on the X-ray scattering intensity being proportional to the mass of the scattering material, separates crystalline scattering from amorphous scattering on the diffractogram, with crystallinity xc=a/(a+b), where a is the crystalline phase scattering intensity and B is the amorphous phase scattering intensity.

The polymer thermal decomposition temperature was tested by characterizing the thermal properties of the prepared SPE by thermogravimetric analysis on a Perkin Elmer device at a heating rate of 10 ℃/min in the range of 30-600 ℃.

2. The method for relevant characterization of the polymers in table 2 is as follows:

lithium ion transfer number (t) of polymer _Li+ ) Measured by a Li/polymer electrolyte/Li symmetric cell at 25 ℃. EIS experiments on symmetric cells were performed using CHI660 electrochemical workstation, frequency: the amplitude of 100 kHz-0.1 Hz is 10mV. Measurement of initial body electricity of symmetrical cell R resistance ^o And interface impedance R _i ^o Then, a polarization voltage (DeltaV) of 10mV was continuously applied, and an initial response current I was recorded _o . When reaching steady-state current I _ss After that, the voltage is stopped and EIS test is performed again, and the volume resistance R of the polarized polymer electrolyte is recorded ^ss Interface resistance R _i ^ss . Substituting formula to obtain t _Li+ ：

The electrochemical window of a polymer electrolyte is often accurately measured using Linear Sweep Voltammetry (LSV). The stainless steel inert electrode is used as a working electrode, the lithium sheet is used as a counter electrode to assemble a button cell, and the testing voltage is in the range of 0-8V and 1mV S at 25 DEG C ^-1 Also using the CHI660 electrochemical workstation.

Polymer glass transition temperature test: the phase transition temperature of the polymer was measured using a Q2000 calorimeter (ta instruments inc.) under a nitrogen atmosphere at a heating rate of 10 ℃/min in the temperature range of-70 to 100 ℃.

3. The method for relevant characterization of the polymers in table 3 is as follows:

the solid electrolyte ionic conductivity testing method comprises the following steps: the ion conductivity of the solid polymer electrolyte is tested by adopting an alternating current impedance method, and the used instrument is an electrochemical workstation of model CHI660E of Shanghai Chen Hua instrument Co. In an argon glove box, assembling the positive electrode shell, the stainless steel gasket, the solid polymer electrolyte, the stainless steel gasket, the elastic sheet and the negative electrode shell into a button cell according to the sequence, wherein the alternating current impedance test frequency is 100 mHz-1000 KHz, the amplitude voltage is 5mV, and the test temperature is 30 ℃. Solid polymer electrolyte ionic conductivity calculation formula:

σ＝L/(R·S)

Wherein R is the bulk impedance (Ω) of the solid polymer electrolyte; l is the solid polymer electrolyte thickness (cm); s is the effective contact area (cm) of the button cell ² )。

The method for testing the cycle performance of the lithium ion battery comprises the following steps: the lithium ion battery is placed on a blue battery charge-discharge test cabinet for charge-discharge cycle test under the conditions of room temperature of 30 ℃ and low temperature of-10 ℃ and 0.5C/0.5C charge-discharge, and the cycle times which are experienced when the capacity is attenuated to 80% of the first discharge capacity are recorded.

Example 1:

(1) Oxalyl chloride and N, N-dimethylformamide are mixed according to a molar ratio of 3.3:1 was added to 50ml of anhydrous acetonitrile and stirred for 4 hours to promote the formation of Vilsmeier-Haack complex. When the solution turned yellow, 4g of 4-styrenesulfonic acid sodium salt was slowly added to the solution at room temperature under a nitrogen atmosphere. The mixture was stirred for 25 hours. Separating NaCl precipitate by filtration to obtain a product;

(2) And adding triethylamine, trifluoromethyl sulfonamide and 4-dimethylaminopyridine into anhydrous acetonitrile in sequence, wherein the addition amount of the triethylamine, the trifluoromethyl sulfonamide and the 4-dimethylaminopyridine accounts for 5% of the mass of the anhydrous acetonitrile, and the molar ratio of the triethylamine to the trifluoromethyl sulfonamide to the 4-dimethylaminopyridine is 2:1:1.5. The mixture was stirred for 0.5 hours to completely dissolve all components. The product solution in (1) was cooled to 0 ℃, then the trifluoromethylsulfonamide mixture was slowly added to the solution and left under vigorous magnetic stirring for 10 hours. The solvent was removed and the resulting brown solid was dissolved in 20ml of dichloromethane. With NaHCO ₃ The solution was washed with aqueous solution and hydrochloric acid. By using excessive K ₂ CO ₃ The acid monomer produced by the neutralization reaction gives 4-styrenesulfonyl (trifluoromethylsulfonyl) imide in the K form. The resulting suspension was stirred for several hours, filtered and dried to give a pale yellow solid. Recrystallizing from water to obtain a final product powder;

(3) Mixing the product of (2) with LiBF ₄ According to the following steps of 1:2 in anhydrous acetonitrile, continuously reacting for 3-6 hours at low temperature, and separating KBF by filtration ₄ Precipitating to obtain the product Li-form 4-styrenesulfonyl (trifluoromethyl sulfonyl) imine, wherein the nuclear magnetism H spectrum is shown in figure 1;

(4) 1g PVDF and 0.203g LiTFSI are dissolved in 20ml acetonitrile solution, and the mixture is fully stirred in an oil bath at 40 ℃ until the mixture is completely dissolved (the rotating speed is 600 r/min);

(5) Adding a 2-hydroxy-2-methyl propiophenone initiator into ethylene carbonate, wherein the mass ratio of the initiator is 1.5%, and fully stirring at a rotating speed of 600r/min under the condition of complete light shielding under the argon atmosphere to enable the initiator to be completely dissolved;

(6) Succinonitrile and LiTFSI are mixed according to a mole ratio of 4:1 fully stirring at 50 ℃ to form a eutectic agent, and then mixing the eutectic agent with the solution obtained in the step (5) according to the volume ratio of 1:1, under the room temperature and argon atmosphere, stirring at a rotating speed of 600r/min under the complete light-shielding condition to form a uniform solution;

(7) Dissolving 0.5g of the Li-form 4-styrenesulfonyl (trifluoromethylsulfonyl) imide of the formula (3) in 10ml of the solution of the formula (6), and fully stirring at a rotating speed of 600r/min under the complete light-shielding condition at 30 ℃ under the argon atmosphere to form a uniform solution;

(8) The solution of (7) and the solution of (4) are fully stirred at the rotating speed of (600 r/min) under the argon atmosphere and the complete light-shielding condition according to the volume ratio of 1:1 at 30 ℃ to form a uniform solution;

(9) And (3) placing the mixed solution in the step (8) into a transition cabin of a glove box, vacuumizing, and carrying out light-shielding ultrasonic treatment for 0.5h to remove bubbles in the mixed solution. And casting the precursor solution into a PTFE plate, placing the PTFE plate under 395nm ultraviolet light for irradiation for 1 hour until no flowing sign exists on the surface of the solution, and then placing the PTFE plate into a vacuum drying oven at 80 ℃ for overnight drying to obtain the ion-dipole mediated elastomer electrolyte film.

(10) Cutting the all-solid-state electrolyte material in the step (9) into a round plate shape with the diameter of 16mm, and assembling the round plate shape into a battery in a glove box filled with argon.

The preparation method of the lithium ion battery of the embodiment is as follows: s1: dissolving 50g of positive electrode material (lithium iron phosphate (LFP)), 4.2g of conductive carbon black, 7.3g of precursor liquid in the step (8) and 2.5g of polyvinylidene fluoride in 100g of NMP, uniformly mixing, coating the mixture on the surface of an aluminum foil current collector, and carrying out ultraviolet irradiation, drying, rolling and slitting to obtain a positive electrode plate; s2: and preparing a solid lithium ion battery cell by the obtained positive electrode plate, solid electrolyte and negative electrode Li plate in a lamination mode, and packaging to obtain the lithium ion battery.

It should be noted that, the positive electrode material lithium iron phosphate LFP adopted in the above lithium ion battery does not limit the positive electrode material of the present invention, and in other specific embodiments, lithium cobalt oxide LCO and lithium-rich positive electrode LRO may be adopted to prepare the battery, and the method is similar to the above operation, or the method is not repeated herein with reference to the existing preparation methods of lithium cobalt oxide batteries and lithium-rich batteries. Since the electrolyte of the battery has a large influence on the charge and discharge performance of the battery, according to the test result of the elastomer electrolyte film in the lithium iron phosphate battery, the elastomer electrolyte film can be presumed to have similar advantages in the lithium cobalt oxide battery and the lithium-rich battery.

Example 2:

(1) Oxalyl chloride and N, N-dimethylformamide are mixed according to a molar ratio of 13.3:1 was added to 50ml of anhydrous acetonitrile and stirred for 5 hours to promote the formation of Vilsmeier-Haack complex. When the solution turned yellow, 4g of 4-styrenesulfonic acid sodium salt was slowly added to the solution at room temperature under a nitrogen atmosphere. The mixture was stirred for 25 hours. Separating NaCl precipitate by filtration to obtain a product;

(2) And adding triethylamine, trifluoromethyl sulfonamide and 4-dimethylaminopyridine into the anhydrous acetonitrile in sequence, wherein the addition amount of the triethylamine, the trifluoromethyl sulfonamide and the 4-dimethylaminopyridine accounts for 6% of the mass of the anhydrous acetonitrile, and the molar ratio of the triethylamine to the trifluoromethyl sulfonamide to the 4-dimethylaminopyridine is 2:1:1.5. The mixture was stirred for 1 hour to completely dissolve all components. The product solution in (1) was cooled to 0 ℃, then the trifluoromethylsulfonamide mixture was slowly added to the solution and left under vigorous magnetic stirring for 10 hours. The solvent was removed and the resulting brown solid was dissolved in 20ml of dichloromethane. With NaHCO ₃ The solution was washed with aqueous solution and hydrochloric acid. By using excessive K ₂ CO ₃ The acid monomer produced by the neutralization reaction gives 4-styrenesulfonyl (trifluoromethylsulfonyl) imide in the K form. The resulting suspension was stirred for several hours, filtered and dried to give a pale yellow solid. Recrystallizing from water to obtain a final product powder;

(3) Mixing the product of (2) with LiBF ₄ According to the following steps of 1:2 in anhydrous acetonitrile, continuously reacting at low temperature for 5 hours, separating KBF by filtration ₄ Precipitating to finally obtain the product Li-form 4-styrenesulfonyl (trifluoromethyl sulfonyl) imine;

(4) 1g PVDF and 0.406g LiTFSI were dissolved in 20ml acetonitrile solution and thoroughly stirred in an oil bath at 40℃at 600r/min until complete dissolution;

(6) Succinonitrile and LiTFSI are mixed according to a mole ratio of 6:1 fully stirring at 50 ℃ to form a eutectic agent, and then mixing the eutectic agent with the solution obtained in the step (5) according to the volume ratio of 1:1, under the room temperature and argon atmosphere, stirring at a rotating speed of 600r/min under the complete light-shielding condition to form a uniform solution;

The preparation method of the lithium ion battery in this embodiment is the same as that in embodiment 1, and will not be described here again.

Example 3:

(1) Oxalyl chloride and N, N-dimethylformamide are mixed according to a molar ratio of 23.3:1 was added to 50ml of anhydrous acetonitrile and stirred for 5 hours to promote the formation of Vilsmeier-Haack complex. When the solution turned yellow, 4g of 4-styrenesulfonic acid sodium salt was slowly added to the solution at room temperature under a nitrogen atmosphere. The mixture was stirred for 25 hours. Separating NaCl precipitate by filtration to obtain a product;

(4) 1g PVDF and 0.609g LiTFSI are dissolved in 20ml acetonitrile solution and stirred well (rotation speed 600 r/min) in an oil bath at 40 ℃ until complete dissolution;

Example 4:

(1) Oxalyl chloride and N, N-dimethylformamide are mixed according to a molar ratio of 30:1 was added to 50ml of anhydrous acetonitrile and stirred for 5 hours to promote the formation of Vilsmeier-Haack complex. When the solution turned yellow, 4g of 4-styrenesulfonic acid sodium salt was slowly added to the solution at room temperature under a nitrogen atmosphere. The mixture was stirred for 25 hours. Separating NaCl precipitate by filtration to obtain a product;

(2) Sequentially adding triethylamine, trifluoromethyl sulfonamide and 4-dimethylaminopyridine into anhydrous acetonitrile, wherein the triethylamineThe addition amount of amine, trifluoromethyl sulfonamide and 4-dimethylaminopyridine accounts for 6% of the mass of the anhydrous acetonitrile, wherein the mol ratio of triethylamine, trifluoromethyl sulfonamide and 4-dimethylaminopyridine is 2:1:1.5. The mixture was stirred for 1 hour to completely dissolve all components. The product solution in (1) was cooled to 0 ℃, then the trifluoromethylsulfonamide mixture was slowly added to the solution and left under vigorous magnetic stirring for 10 hours. The solvent was removed and the resulting brown solid was dissolved in 20ml of dichloromethane. With NaHCO ₃ The solution was washed with aqueous solution and hydrochloric acid. By using excessive K ₂ CO ₃ The acid monomer produced by the neutralization reaction gives 4-styrenesulfonyl (trifluoromethylsulfonyl) imide in the K form. The resulting suspension was stirred for several hours, filtered and dried to give a pale yellow solid. Recrystallizing from water to obtain a final product powder;

(4) 1g PVDF and 0.812g LiTFSI were dissolved in 20ml acetonitrile solution and thoroughly stirred in an oil bath at 40℃at 600r/min until complete dissolution;

Comparative example 1-1:

(1) Oxalyl chloride and N, N-dimethylformamide are mixed according to a molar ratio of 3.3:1 was added to 50ml of anhydrous acetonitrile and stirred for 5 hours to promote the formation of Vilsmeier-Haack complex. When the solution turned yellow, 4g of 4-styrenesulfonic acid sodium salt was slowly added to the solution at room temperature under a nitrogen atmosphere. The mixture was stirred for 25 hours. Separating NaCl precipitate by filtration to obtain a product;

(2) And adding triethylamine, trifluoromethyl sulfonamide and 4-dimethylaminopyridine into the anhydrous acetonitrile in sequence, wherein the addition amount of the triethylamine, the trifluoromethyl sulfonamide and the 4-dimethylaminopyridine accounts for 6% of the mass of the anhydrous acetonitrile, and the molar ratio of the triethylamine to the trifluoromethyl sulfonamide to the 4-dimethylaminopyridine is 2:1:1.5. The mixture was stirred for 1 hour to completely dissolve all components. The product solution in (1) was cooled to 0 ℃, then the trifluoromethylsulfonamide mixture was slowly added to the solution and left under vigorous magnetic stirring for 10 hours. The solvent was removed and the resulting brown solid was dissolved in 20ml of dichloromethane. With NaHCO ₃ The solution was washed with aqueous solution and hydrochloric acid. By using excessive K ₂ CO ₃ Neutralization of the acid monomer produced to give 4-styrene in K formSulfonyl (trifluoromethylsulfonyl) imide. The resulting suspension was stirred for several hours, filtered and dried to give a pale yellow solid. Recrystallizing from water to obtain a final product powder;

(4) 1g PVDF-HFP and 0.3g LiTFSI were dissolved in 20ml acetonitrile solution and stirred well (rotation speed 600 r/min) in an oil bath at 50℃until complete dissolution;

Comparative example 2-1:

(4) 1g PVDF-HFP and 0.6g LiTFSI were dissolved in 20ml acetonitrile solution and stirred well (rotation speed 600 r/min) in an oil bath at 50℃until complete dissolution;

Comparative example 3-1:

(4) 1g PVDF-HFP and 0.9g LiTFSI were dissolved in 20ml acetonitrile solution and stirred well (rotation speed 600 r/min) in an oil bath at 50℃until complete dissolution;

Comparative example 4-1:

(2) And adding triethylamine, trifluoromethyl sulfonamide and 4-dimethylaminopyridine into the anhydrous acetonitrile in sequence, wherein the addition amount of the triethylamine, the trifluoromethyl sulfonamide and the 4-dimethylaminopyridine accounts for 6% of the mass of the anhydrous acetonitrile, and the molar ratio of the triethylamine to the trifluoromethyl sulfonamide to the 4-dimethylaminopyridine is 2:1:1.5. The mixture was stirred for 1 hour to completely dissolve all components. The product solution in (1) was cooled to 0 ℃, then the trifluoromethylsulfonamide mixture was slowly added to the solution and left under vigorous magnetic stirring for 10 hours. Removing the solvent The brown solid obtained was dissolved in 20ml of dichloromethane. With NaHCO ₃ The solution was washed with aqueous solution and hydrochloric acid. By using excessive K ₂ CO ₃ The acid monomer produced by the neutralization reaction gives 4-styrenesulfonyl (trifluoromethylsulfonyl) imide in the K form. The resulting suspension was stirred for several hours, filtered and dried to give a pale yellow solid. Recrystallizing from water to obtain a final product powder;

(4) 1g PVDF-HFP and 1g LiTFSI were dissolved in 20ml acetonitrile solution and stirred well (rotation speed 600 r/min) in an oil bath at 50℃until complete dissolution;

Example 5:

(3) Mixing the product of (2) with LiBF ₄ According to the following steps of 1:2 in anhydrous acetonitrile, continuously reacting at low temperature for 5 hours, separating KBF by filtration ₄ Precipitation to finally obtain the product Li-form 4-styrene Sulfonyl (trifluoromethylsulfonyl) imide;

(5) Adding a 2-hydroxy-2-methyl propiophenone initiator into vinylene carbonate, wherein the mass ratio of the initiator is 1.5%, and fully stirring at a rotating speed of 600r/min under the condition of completely avoiding light in an argon atmosphere to completely dissolve the initiator;

(6) N-methylacetamide and LiTFSI are mixed according to a mol ratio of 4:1 fully stirring at 50 ℃ to form a eutectic agent, and then mixing the eutectic agent with the solution obtained in the step (5) according to the volume ratio of 1:1, under the room temperature and argon atmosphere, stirring at a rotating speed of 600r/min under the complete light-shielding condition to form a uniform solution;

Comparative example 5-1:

(4) 1g PVDF-HFP and 0.9g LiTFSI were dissolved in 20ml acetonitrile solution and stirred well (rotation speed 600 r/min) in an oil bath at 40℃until complete dissolution;

Example 6:

(2) And adding triethylamine, trifluoromethyl sulfonamide and 4-dimethylaminopyridine into the anhydrous acetonitrile in sequence, wherein the addition amount of the triethylamine, the trifluoromethyl sulfonamide and the 4-dimethylaminopyridine accounts for 6% of the mass of the anhydrous acetonitrile, and the molar ratio of the triethylamine to the trifluoromethyl sulfonamide to the 4-dimethylaminopyridine is 2:1:1.5. Stirring the mixtureMix for 1 hour to completely dissolve all components. The product solution in (1) was cooled to 0 ℃, then the trifluoromethylsulfonamide mixture was slowly added to the solution and left under vigorous magnetic stirring for 10 hours. The solvent was removed and the resulting brown solid was dissolved in 20ml of dichloromethane. With NaHCO ₃ The solution was washed with aqueous solution and hydrochloric acid. By using excessive K ₂ CO ₃ The acid monomer produced by the neutralization reaction gives 4-styrenesulfonyl (trifluoromethylsulfonyl) imide in the K form. The resulting suspension was stirred for several hours, filtered and dried to give a pale yellow solid. Recrystallizing from water to obtain a final product powder;

(5) Adding a 2-hydroxy-2-methyl propiophenone initiator into polyethylene glycol diacrylate, wherein the mass ratio of the initiator is 1%, and fully stirring at a rotating speed of 600r/min under the condition of completely avoiding light under the argon atmosphere to ensure that the initiator is completely dissolved;

Comparative example 6-1:

The prepared elastomer electrolyte film and the prepared elastomer electrolyte battery are respectively subjected to performance detection, test charts are shown in fig. 2, 3, 4 and 5, and test results are shown in tables 1, 2 and 3.

Wherein fig. 2 and 3 are a thermogravimetric and SEM image of the ion-dipole mediated elastomer electrolyte prepared in example 3 of the present invention, respectively. Among them, fig. 2 shows that the elastomer polymer electrolyte prepared in example 3 has a high pyrolysis temperature, and the surface polymer is completely cured without liquid due to the temperature of-180 ℃ for the first weight loss. The surface of the elastomeric polymer electrolyte formed by in situ polymerization in fig. 3 is smooth and flat and has no bubbles and voids formed, which is critical to interfacial contact stability.

Fig. 4 and 5 show the charge and discharge performance of the lithium ion battery of example 3 carrying the self-adaptive deformation elastomer polymer electrolyte membrane according to the present invention. Wherein, fig. 4 is a cross-sectional view of the electrode/elastomer electrolyte after the completion of the cycle, it can be seen that after > 500 cycles, the electrode/electrolyte interface after the cycle is still completely bonded without gaps due to the excellent self-adaptation capability of the elastomer polymer electrolyte. Fig. 5 is a charge-discharge curve of the LFP full cell, and it can be seen that the polarization of the cell did not change after 200 cycles, which also laterally reflects the excellent performance of the interface.

TABLE 1 results of physical Properties test of elastomeric electrolyte films

TABLE 2 Table of results of electrolyte film electromigration ability and thermal stability test

TABLE 3 electrolyte ion conductivity and cycling performance test results for lithium ion batteries

As can be seen from the data of tables 1-3, the ion-dipole mediated elastomeric polymer electrolytes of the present invention have higher room temperature ionic conductivity, excellent low temperature cycling stability and interfacial stability, and lithium ion batteries assembled using the solid state electrolytes of the present invention have better cycling performance.

Taking example 3 and comparative example 3-1 as examples, the solid electrolyte prepared by polymerization prepared by PVDF-HFP in comparative example 3-1 has improved mechanical properties but has poor lithium-conducting properties and poor cycle properties of the assembled solid-state battery, compared to example 3.

In the examples, N-methylacetamide and LiTFSI are used as additives to form eutectic agent, and the conductivity is relatively low, so that the capacity of the solid-state battery decays too fast, and the impedance change before and after circulation is maximum.

The comparative cases of examples 1-2 and 4-5 with their corresponding comparative examples are identical to those of example 1 and comparative example 1-1, and no further analysis is performed here.

Example 3 compared to example 6, when preparing a solid electrolyte prepared by polymerization of vinylene carbonate, the ionic conductivity of the solid electrolyte and the cycling performance of the lithium ion battery were slightly inferior to those of the polymer solid electrolyte prepared by VEC and the lithium ion battery.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific details of the above embodiments, and various simple modifications can be made to the technical solution of the present invention within the scope of the technical concept of the present invention, and all the simple modifications belong to the protection scope of the present invention.

In addition, the specific features described in the above embodiments may be combined in any suitable manner without contradiction. The various possible combinations of the invention are not described in detail in order to avoid unnecessary repetition.

Moreover, any combination of the various embodiments of the invention can be made without departing from the spirit of the invention, which should also be considered as disclosed herein.

Claims

1. A method for preparing an ion-dipole mediated elastomer electrolyte membrane, characterized by: the method comprises the following steps:

2. The method of preparing an ion-dipole mediated elastomeric electrolyte film according to claim 1, wherein: the molar ratio of oxalyl chloride to N, N-dimethylformamide in the step (1) is 3:1-30:1, preferably 13:1 to 24:1; the addition amount of the sodium styrenesulfonate is 1.1-1.2 times of the molar mass of the N, N-dimethylformamide;

3. The method of preparing an ion-dipole mediated elastomeric electrolyte film according to claim 1, wherein: the addition amount of the lithium salt in the step (3) is 1 to 1.5 times of the molar amount of the powder Y, the reaction temperature is 30 to 150 ℃, preferably 80 to 100 ℃ and the reaction time is 3 to 6 hours;

4. The method of preparing an ion-dipole mediated elastomeric electrolyte film according to claim 1, wherein: the initiator in the step (5) is a photoinitiator or a thermal initiator, and the addition amount is 1-5% of the unsaturated ester monomer;

5. The method of preparing an ion-dipole mediated elastomeric electrolyte film according to claim 1, wherein: in the step (6), the low co-solvent is prepared by mixing one or more of urea, methyl urea, N-methylacetamide, succinonitrile and thiourea with lithium salt, preferably, the low co-solvent is prepared by mixing N-methylacetamide or succinonitrile with LiTFSI at a ratio of 10:1 to 1:1 at a temperature of between 40 and 55 ℃;

6. The method of preparing an ion-dipole mediated elastomeric electrolyte film according to claim 1, wherein: the solvent is at least one of anhydrous acetonitrile, acetone, dimethyl sulfoxide, toluene, xylene, cyclohexane, cyclohexanone, pyridine or phenol; the protective atmosphere is nitrogen or at least one of zero group element gases of the periodic table; the ultraviolet irradiation treatment is irradiation for 0.5-3 hours under ultraviolet light with the wavelength of 300-400 nm.

7. An ion-dipole mediated elastomeric electrolyte membrane prepared according to the method of any one of claims 1-6.

8. The ion-dipole mediated elastomeric electrolyte film of claim 7 wherein: the polymer number average molecular weight of the ion-dipole mediated elastomer electrolyte membrane is 5000-500000, preferably 10000-45000; the crystallinity of the polymer is 10-50, preferably 20-30; the thermal decomposition temperature is 200-600 ℃, preferably 295-534 ℃; young's modulus of 1-15GPa, preferably 3-11GPa; the solid electrolyte ion migration number is 0.1 to 1.0, preferably 0.4 to 0.7; the electrochemical stability window voltage of the solid electrolyte is 3-6V, preferably 4.2-6V; the polarization voltage of the solid electrolyte half cell is 50-300mV, preferably 100-200mV; the glass transition temperature is-40 to-70 ℃, preferably-50 to 60 ℃; the ionic conductivity at 30℃is 0.3-3mS/cm, preferably 1.2-2mS/cm.

9. Use of an ion-dipole mediated elastomeric electrolyte membrane according to claim 7 or 8 in a solid electrolyte material for a lithium metal battery.

10. A battery comprising the ion-dipole mediated elastomeric electrolyte film of claim 7 or 8, preferably the battery is a lithium cobalt oxide-lithium metal battery, a lithium iron phosphate-lithium metal battery or a lithium rich positive electrode-lithium metal battery, the battery operating temperature range is-20 ℃ to 100 ℃, more preferably a lithium iron phosphate-lithium metal battery, the lithium iron phosphate-lithium metal battery having a capacity fade to 80% of the first discharge capacity after cycling 100-600 times at 30 ℃; after cycling 50-300 times at-10 ℃, the capacity decays to 80% of the first discharge capacity.