CN115160233A

CN115160233A - Self-adaptive deformation elastomer electrolyte, electrode and battery

Info

Publication number: CN115160233A
Application number: CN202210926220.1A
Authority: CN
Inventors: 陈本
Original assignee: Individual
Current assignee: Xiamen Wuren Juneng Enterprise Management Partnership (Limited Partnership)
Priority date: 2022-08-03
Filing date: 2022-08-03
Publication date: 2022-10-11

Abstract

The invention relates to a self-adaptive deformation elastomer electrolyte, an electrode and a battery, wherein the self-adaptive deformation elastomer electrolyte takes unsaturated ester as a flexible main chain, and micromolecule thiols and bifunctional imidazole ionic liquid monomers with unsaturated olefin and amino functional groups are randomly copolymerized on the flexible main chain. The flexible main chain and the imidazole monomer are effectively crosslinked by utilizing the 'click chemical reaction' of olefin-mercaptan, the mercaptan chain segment can effectively improve the rigidity of the polymer, and the amino functional group can form a dynamic chemical bond in the polymer, so that the polymer has excellent elastic deformation. The polymer solid electrolyte film with self-adaptive high elasticity is obtained by a curing method, has excellent elasticity, can effectively avoid the problems of poor interface contact and the like caused by electrode expansion in the long circulation process of a battery, and has excellent flame retardant property, interface contact property, high room-temperature ionic conductivity and good electrochemical window.

Description

Self-adaptive deformation elastomer electrolyte, electrode and battery

Technical Field

The invention relates to the technical field of energy storage, in particular to an elastomer electrolyte, an electrode and a battery with various self-adaptive deformations.

Background

Energy storage batteries are developed to the present, and lithium ion batteries are widely applied to the fields of 3C products and communications due to the advantages of high energy density, high working voltage, excellent cycling stability, rapid charge and discharge, low pollution and the like. At present, liquid organic electrolyte such as esters and ethers is mostly adopted by lithium ion batteries as electrolyte, the liquid electrolyte has high ionic conductivity and good interface wettability, but the liquid organic electrolyte has the safety problems of leakage, easy volatilization, easy combustion and even explosion and the like. In addition, during cycling of the battery, the formation of lithium dendrites can also puncture the separator, causing a short circuit in the battery. The use of a solid electrolyte instead of a conventional organic liquid electrolyte is considered to be an effective way to solve the above-mentioned problems. Generally, the thermal stability, chemical stability, electrochemical stability, and mechanical strength of solid electrolytes are generally superior to all liquid electrolytes. And the use of the solid electrolyte can fundamentally eliminate potential safety hazards in theory. Meanwhile, the electrochemical stability window of the solid electrolyte is superior to that of an organic electrolyte, so that the solid electrolyte can be used for high-voltage anode materials, and further the energy density of the battery is improved. In addition, the solid electrolyte also enables a high lithium ion transport coefficient to be achieved, thereby promoting more uniform lithium metal deposition. In addition to the above advantages, the solid electrolyte also has the advantages of wide working temperature range, high deformation and the like.

The solid electrolytes currently under development mainly include inorganic solid electrolytes, organic-inorganic composite solid electrolytes, and polymer solid electrolytes. The polymer solid electrolyte has the advantages of excellent interface performance, high elastic deformation, arbitrary cutting, suitability for large-scale preparation and the like. Patent publication No. CN114188603A discloses a nano-phase separated solid polymer electrolyte with good cycling stability at room temperature. However, the elastic property is poor, the preparation process is complex, the contact wettability with an electrode material is poor, and the large-scale application in lithium ion batteries is difficult. The organic-inorganic composite solid electrolyte is a lithium ion conductor composed of inorganic particles as a filler mixed in a polymer matrix. The organic-inorganic composite solid electrolyte has good chemical stability, high ionic conductivity and good mechanical processing performance, and can be well wetted with electrodes. However, most organic-inorganic composite electrolyte chambers have poor film forming property, and the electrodeless fillers are easy to agglomerate to cause poor elasticity, so that the organic-inorganic composite electrolyte chambers are difficult to apply to large-scale lithium metal batteries.

Patent publication No. CN 108878959A proposes an isocyanate-based composite all-solid-state electrolyte, which comprises a flexible chain segment compound, inorganic nanoparticles, conductive lithium salt, an organic solvent and the like, and has an ionic conductivity of more than 10 at room temperature ^-5 S cm ^-1 But its mechanical properties are poor. The method is a common modification means of polymer electrolytes at present through copolymerization, crosslinking and the like, and can effectively improve the mechanical property of the electrolyte.

Patent publication No. CN 110951036A proposes a casting polyurethane elastomer electrolyte, which is prepared by preparing a prepolymer from polyether glycol and diisocyanate, mixing the prepolymer with lithium salt for complex reaction, and reacting with a chain extender to prepare the casting polyurethane elastomer electrolyte, and curing and molding the casting polyurethane elastomer electrolyte at room temperature to form a crosslinked polymer electrolyte. The elastomer electrolyte has good mechanical property and physical property, has the advantages of high elasticity, high strength, high elongation and the like, but has low ionic conductivity at room temperature (>10 ^-7 S cm ^-1 )。

Patent publication No. CN 112421104A proposes an elastomer epoxy resin-based electrolyte, which solves the technical problems of impurities introduced in the preparation process of the existing crosslinked solid polymer electrolyte, the harm of a used solvent and the narrow working temperature range of the existing thermoplastic polymer solid electrolyte. However, the elastomer polymer electrolyte has low room-temperature ionic conductivity, and the adoption of an epoxy resin synthesis mode is complex, so that the application of a room-temperature lithium ion battery is difficult to realize.

Disclosure of Invention

The invention aims to overcome the problems of low ionic conductivity and low elasticity of the electrolyte of the conventional energy storage battery, and provides various self-adaptive deformation elastomer electrolytes, electrodes and batteries. Specifically, aiming at the problem that interface impedance is increased due to poor contact caused by electrode expansion, a polymer skeleton formed by random copolymerization of unsaturated ester and a thiol crosslinking agent has the advantages of high mechanical strength and high elasticity, and a side chain polyion liquid segment grafted on the skeleton has the advantage of high conductivity.

According to the invention, through molecular design, a flexible chain segment and a small molecular cross-linking agent are introduced to prepare a polymer skeleton with high elastic deformation, and a polyion liquid side chain is introduced into a polymer main chain to form an all-solid-state electrolyte, so that not only can the ionic conductivity be obviously improved, but also the mechanical property of the material and the stability of lithium metal can be improved, and the commercialization process of the solid electrolyte is promoted. According to the invention, unsaturated ester is used as a flexible main chain, and micromolecular thiols and bifunctional imidazole ionic liquid monomers with unsaturated olefin and amino functional groups are randomly copolymerized on the flexible main chain. The flexible main chain and the imidazole monomer are effectively crosslinked by utilizing the 'click chemical reaction' of olefin-mercaptan, the mercaptan chain segment can effectively improve the rigidity of the polymer, and the amino functional group can form a dynamic chemical bond in the polymer, so that the polymer has excellent elastic deformation.

In particular, by defining the composition of the polymer in the solid electrolyte, the elastic properties of the solid electrolyte can be effectively improved, thereby solving the interface problem caused by the expansion of the electrode. Aiming at the problems of impurities, solvent using harm, room temperature ionic conductivity and the like of the existing solid polymer electrolyte in the preparation process, the flexible chain segment is introduced to play a role in transmitting ions, the polymer electrolyte framework is formed by adopting a small molecular rigid cross-linking agent, and the polyion liquid side chain is grafted at the same time, so that the elastomer all-solid electrolyte membrane with high voltage resistance, high flexibility, high elasticity, high room temperature ionic conductivity and simple preparation process and the electrolyte preparation method without solvent are provided, the problem of high interface impedance caused by electrode volume change in the battery circulation process is reduced, and the possibility of gaps in the electrolyte/electrode interface is reduced.

In the preparation method of the bifunctional ionic liquid provided by the invention, alkenyl imidazole and halogenated amine salt react to form amino-alkenyl bifunctional imidazole ionic liquid [ X]VIm-NH ₂ (ii) a And then carrying out ion exchange in an alkali metal lithium salt solution to obtain the bifunctional ionic liquid with alkali metal lithium salt anions, wherein the bifunctional ionic liquid is used as one of monomers for forming an electrolyte polymer, and carries out a crosslinking reaction of random copolymerization with an unsaturated ester monomer under the action of a crosslinking agent under the action of an initiator, and the obtained polymer film is an elastomer electrolyte self-supporting film, and has excellent self-adaptive capacity and excellent ion transmission capacity. The self-adaptive capacity refers to that gaps are formed on an electrolyte/electrode interface due to expansion and contraction of electrodes in the long-term charge and discharge process of the battery, and polymer electrolyte fills the gaps formed on the interface due to excellent elastic property and dynamic chemical bonds of the polymer electrolyte, so that the full battery can stably circulate for a long time, the formation of dendrites is inhibited, and the interface impedance can be reduced.

The self-adaptive deformation elastomer electrolyte provided by the invention is formed by curing a precursor solution under ultraviolet illumination, wherein the precursor solution consists of an initiator, an unsaturated ester monomer, a cross-linking agent, a bifunctional ionic liquid monomer and an alkali metal salt; the initiator and alkali metal salt are sufficiently dissolved by the unsaturated ester monomer, crosslinker and bifunctional ionic liquid monomer and solvation of the monomers dissociates the alkali metal cation; the unsaturated ester monomer, the bifunctional ionic liquid monomer and the cross-linking agent are subjected to a cross-linking reaction of random copolymerization under the action of an initiator, so that a film can be formed, and a block or a particle can be formed according to application requirements.

The specific scheme is as follows:

a preparation method of bifunctional ionic liquid comprises the following steps:

(1) Mixing alkenyl imidazole and a solvent to obtain an alkenyl imidazole solution;

(2) Mixing the halogenated amine salt and ethanol, and then stirring and refluxing for 0.5-2 hours at the temperature of 60-80 ℃ under the protective atmosphere to obtain a reaction solution;

(3) Adding the reaction solution into the alkenyl imidazole solution, continuously reacting for 16-24 hours at room temperature, and drying to remove the solvent to obtain a solid;

(4) Adding the solid to an alkaline solution, followed by recrystallization from ethanol to obtain an amino-alkenyl bifunctional imidazolium ionic liquid [ X ] with a halogen element]VIm-NH ₂ ；

(5) Subjecting the obtained [ X ] to]VIm-NH ₂ And alkali metal lithium salt are respectively added into water, then mixed and continuously stirred to carry out anion exchange, so that [ X ] in the ionic liquid]By exchange for anions [ Y ] in lithium salts of alkali metals]Obtaining the difunctional ionic liquid VIm-NH ₂ [Y]。

Further, the alkenyl imidazole is any one of 1-vinyl imidazole, 1-allyl-3-methyl imidazole chloride or 1-allyl-3-methyl imidazole;

optionally, the solvent is any one of methanol, ethanol, acetone, butanol and acetonitrile;

optionally, the halogenated amine salt is any one of 2-chloroethylamine hydrochloride, 2-bromoethylamine hydrobromide, N-chlorosuccinimide, N-bromosuccinimide, N-chloroacetamide or N-bromoacetamide;

optionally, the alkali metal lithium salt is LiAsF ₆ 、LiDFOB、LiBOB、LiCF ₃ SO ₃ 、LiN(CF ₃ SO ₂ ) ₂ 、LiN(C ₂ F ₅ SO ₂ ) ₂ 、LiPF ₆ 、LiN(CF ₃ SO ₂ )(C ₄ F ₉ SO ₂ )、LiTDI、LiC(CF ₃ SO ₂ ) ₃ 、LiBF ₄ 、LiC(C ₂ F ₅ SO ₂ ) ₃ 、LiClO ₄ At least one of them.

Further, the mass ratio of the alkenyl imidazole and the solvent is 1:1-1:5, preferably 1:2-1:3;

optionally, the mass ratio of the halogenated amine salt to the ethanol is 1:1-1:3; preferably 1.5-1;

optionally, the temperature of the stirring reflux in the step (2) is 65-75 ℃, preferably 70-75 ℃;

optionally, in the step (3), the mass ratio of the reaction solution to the alkenyl imidazole solution is 1:0.2-1.5, mixing the two, reacting, drying to remove the solvent after the reaction is finished, and repeatedly washing the product with one or more of ethyl acetate, acetone and methanol to make the product reach constant weight to obtain a solid;

optionally, adding the solid into an alkali solution in the step (4), adjusting the pH =7.5-8, and then performing recrystallization purification;

optionally, step (5) is carried out by subjecting the obtained [ X ] to]VIm-NH ₂ And alkali metal lithium salt are respectively added into water, the mass concentration of the solution is 40-50 wt%, and when the two are mixed, the aqueous solution of the alkali metal lithium salt and [ X ] are mixed]VIm-NH ₂ The volume ratio of the aqueous solution is 1:1-1:3; mixing, stirring continuously for 16-32 hours at room temperature for anion exchange, and fully drying the product for 10-30 hours under the vacuum condition of 60-80 ℃ to obtain the difunctional ionic liquid VIm-NH ₂ [Y]。

The invention also provides the bifunctional ionic liquid prepared by the preparation method of the bifunctional ionic liquid.

The invention also discloses an elastomer electrolyte with self-adaptive deformation, which is prepared by the following steps: mixing an unsaturated ester monomer, the difunctional ionic liquid, an alkali metal salt, an initiator and a cross-linking agent, and curing the obtained precursor solution under the ultraviolet irradiation condition to obtain the self-adaptive deformation elastomer electrolyte;

preferably, the preparation method comprises the following steps:

s1, adding the alkali metal lithium salt into the unsaturated ester monomer, fully stirring in a protective gas atmosphere to completely dissolve the alkali metal lithium salt, then adding the cross-linking agent, and uniformly stirring to obtain a solution A;

s2, mixing the difunctional ionic liquid with the liquid A, and uniformly stirring in a protective gas atmosphere to obtain a liquid B;

s3, adding the initiator into the solution B, and uniformly stirring in a dark place in a protective gas atmosphere to obtain a precursor solution;

s4, adding the precursor solution into a mold, standing the precursor solution, then carrying out ultraviolet light treatment, and curing to form a film;

s5, drying the film in a vacuum oven to obtain the self-adaptive deformation elastomer electrolyte.

Further, the unsaturated ester monomer is at least one of polyethylene glycol diacrylate, n-butyl acrylate, methyl methacrylate, vinyl acetate, vinylene carbonate, ethylene carbonate, ethyl-2-cyanoacrylate, polyethylene glycol methyl ether acrylate, methyl ethyl-cyanoacrylate, ethoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate, ditrimethylolpropane tetraacrylate, 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, hydroxyethyl acrylate, and derivatives thereof; preferably, the unsaturated ester monomer is at least one of polyethylene glycol diacrylate and polyethylene glycol methyl ether acrylate;

optionally, the alkali metal salt is LiAsF ₆ 、LiDFOB、LiBOB、LiCF ₃ SO ₃ 、LiN(CF ₃ SO ₂ ) ₂ 、LiN(C ₂ F ₅ SO ₂ ) ₂ 、LiPF ₆ 、LiN(CF ₃ SO ₂ )(C ₄ F ₉ SO ₂ )、LiTDI、LiC(CF ₃ SO ₂ ) ₃ 、LiBF ₄ 、LiC(C ₂ F ₅ SO ₂ ) ₃ 、LiClO ₄ At least one of (1); preferably, the alkali metal salt is at least one of LiTFSI, liFSI, liBOB;

optionally, the initiator is a photoinitiator, preferably a free radical photoinitiator or a cationic photoinitiator, wherein: the free radical photoinitiator is preferably at least one of dialkoxyacetophenone, alpha-hydroxyalkylphenone, acylphosphine oxide, benzoins, diphenyl (2,4,6 trimethylbenzoyl) phosphine oxide, 2-methyl 1 (4 methylthiophenyl) 2 morpholine 1 acetone, 2-hydroxy-2-methylphenylpropane-1-one; the cationic photoinitiator is preferably at least one of onium salts, metallorganics, organosilanes, diaryliodonium salts, triarylsulfonium salts and arylferrocenium salts; optionally, the cross-linking agent is at least one of pentaerythritol tetramercaptoacetate, trimethylolpropane tris (3-mercaptopropionate), trimethylolpropane tris (2-mercaptoacetate)), pentaerythritol tetrakis (mercaptoacetate), mercapto) propylmethylsiloxane, and derivatives thereof.

Further, the adding amount of the alkali metal lithium salt in the S1 is 10-50% of the mass of the unsaturated ester monomer, and the adding amount of the cross-linking agent is 1-10% of the mass of the unsaturated ester monomer;

optionally, the adding amount of the bifunctional ionic liquid in the S2 is 10-60% of the mass of the liquid A;

optionally, the amount of the initiator in S3 is 0.1-2% of the mass of the liquid B.

Further, the molecular weight of the self-adaptive deformation elastomer electrolyte is 10000-100000, preferably 40000-50000; the crystallinity is 10-65%, preferably 20-30%; the thermal decomposition temperature is 250-550 ℃, preferably 300-400 ℃; the elastic modulus is 100-510%, preferably 200-300%; shore hardness is 10-50A, preferably 20-30A; young's modulus of 1-20GPa, preferably 10-15GPa; the tensile strength is 1-40MPa, preferably 30-40MPa; the conductivity is from 0.2 to 2.5mS/cm, preferably from 2.0 to 2.5mS/cm.

The invention also discloses an electrode containing the self-adaptive deformation elastomer electrolyte, and the preparation method comprises the steps of coating a mixed solution consisting of an active material, a conductive agent, a bonding agent and the precursor solution on the surface of a metal current collector, and obtaining the electrode after ultraviolet illumination, drying, rolling and slitting; preferably, the active material is lithium cobaltate, lithium iron phosphate or a lithium-rich positive electrode material.

The invention also protects a battery comprising said electrode, characterized in that: the number of cycles that the battery undergoes when its capacity decays to 80% of its first discharge capacity is 150-580, preferably 500-580.

Has the advantages that:

in the invention, the difunctional ionic liquid can form a chain after polymerization, and a dynamic hydrogen bond formed by the side chain of the difunctional polyionic liquid has good compatibility and adaptability between the electrolyte matrix and the positive and negative electrodes, thereby greatly improving the energy density and the cycle life of the battery.

Moreover, the self-adaptive elastomer all-solid-state electrolyte provided by the invention can be used for grafting the bifunctional ionic liquid by matching different polyester flexible chain segments and a rigid thiol cross-linking agent as a matrix, which is also one of the reasons that the polymer electrolyte has high elasticity. The polymer film formed by photocuring can improve the mechanical property of the solid electrolyte due to a high crosslinking structure.

Furthermore, the all-solid-state electrolyte of the self-adaptive elastomer provided by the invention has the optimal cross-linked network density, shows a high elastic state and certain toughness macroscopically, has better flexibility, and has basic conditions for large-scale preparation. Compared with a PEO-based electrolyte, the self-adaptive elastomer all-solid-state electrolyte provided by the invention has high ionic conductivity at room temperature, good thermal stability and good interface stability, and can form a compact interface contact layer.

In a word, the preparation process provided by the invention is simple, curing agents, solvents and heating are not needed in the production and processing processes, the environment is friendly, and the industrial production and the commercial application are easy to realize. And because the reaction does not need a solvent, the all-solid electrolyte can be used for preparing an all-battery in an in-situ curing mode, and the interface contact between the electrolyte and an electrode is greatly optimized. The electrolyte system without liquid greatly reduces the occurrence of potential safety hazard and conforms to the future development planning of the battery industry.

Drawings

In order to illustrate the technical solution of the present invention more clearly, the drawings will be briefly described below, and it is apparent that the drawings in the following description relate only to some embodiments of the present invention and are not intended to limit the present invention.

FIG. 1 shows the bifunctional ionic liquid monomer VIm-NH prepared in example 1 of the present invention ₂ [TFSI]Nuclear magnetic H spectrum of (1).

FIG. 2 is a diagram of a bifunctional ionic liquid prepared in example 1 of the present invention.

FIG. 3 is a pictorial representation of a self-adaptive deformation elastomeric polymer electrolyte membrane prepared in accordance with example 7 of the present invention.

FIG. 4 is an SEM image of a self-adaptive deformation elastomeric polymer electrolyte membrane prepared in example 7 of the present invention, at 150 times magnification.

FIG. 5 is a SEM image of a cross section of a lithium ion battery of the invention carrying the adaptively deformed elastomeric polymer electrolyte membrane, taken after cycling, at 100 times magnification.

Detailed Description

Preferred embodiments of the present invention will be described in more detail below. While the following describes preferred embodiments of the present invention, it should be understood that the present invention may be embodied in various forms and should not be limited by the embodiments set forth herein. The examples do not specify particular techniques or conditions, and are performed according to the techniques or conditions described in the literature in the art or according to the product specifications. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available. In the following examples, "%" means weight percent, unless otherwise specified.

The test methods used below included:

before testing the number average molecular weight and the crystallinity of the polymer, the elastomer solid electrolyte is firstly treated in dimethyl sulfoxide at 80 ℃ for 24 hours, filtered to obtain supernatant, then subjected to column chromatography separation to obtain the polymer, and then the polymer obtained by separation is tested for the number average molecular weight and the crystallinity. The number average molecular weight and crystallinity of the polymer were measured as follows:

polymer number average molecular weight test: dissolving the polymer in a solvent to form a uniform liquid system, carrying out suction filtration on the uniform liquid system, taking a sample, detecting the sample in a gel chromatograph of Japan Shimadzu GPC 20A, and collecting molecular weight information.

Polymer crystallinity test: the polymer is ground into powder, an Shimadzu XRD-7000 type X-ray diffractometer is adopted, a theta/theta scanning mode is adopted, a sample is horizontally placed, and the crystallinity of the polymer is tested. The polymer crystallinity, based on the X-ray scattering intensity being proportional to the mass of the scattering material, separates crystalline scattering from amorphous scattering on the diffraction diagram, 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 as follows: the thermal properties of the prepared SPEs were characterized by thermogravimetric analysis on a Perkin Elmer apparatus at a heating rate of 10 ℃/min in the range of 30-600 ℃.

The polymer elastic modulus was tested as follows: the stress-strain curve of the SPE was obtained using a tensile tester at a tensile speed of 0.2 cm/min.

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

The method for testing the ionic conductivity of the solid electrolyte comprises the following steps: the ionic conductivity of the solid polymer electrolyte is tested by adopting an alternating current impedance method, and the used instrument is an electrochemical workstation of CHI660E model of Shanghai Chenghua Instrument Limited. In an argon glove box, a button cell is assembled according to the sequence of a positive electrode shell, a stainless steel gasket, a solid polymer electrolyte, a stainless steel gasket, a spring plate and a negative electrode shell, the alternating current impedance test frequency is 100 mHz-1000 KHz, the amplitude voltage is 5mV, and the test temperature is 30 ℃. The ionic conductivity of the solid polymer electrolyte is calculated by the formula:

σ＝L/(R·S)

wherein R is the bulk impedance (Ω) of the solid polymer electrolyte; l is 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: and (3) placing the lithium ion battery on a blue battery charging and discharging test cabinet to carry out charging and discharging cycle test, wherein the test conditions are 30 ℃ and 0.5C/0.5C charging and discharging, and recording the cycle times when the capacity is attenuated to 80% of the first discharge capacity. The improvement of the interface by the adaptive elastomer polymer electrolyte is judged by measuring the change of the interface impedance before and after the cycle.

Example 1:

1-vinyl imidazole and ethanol in a mass ratio of 1:1 were charged into a four-necked flask equipped with a reflux condenser, and first stirred well at room temperature for 0.5 hour. Then mixing the 2-chloroethylamine hydrochloride and the ethanol according to the mass ratio of 1:1 in a beaker, and then stirring and refluxing for 0.5 hour at 70 ℃ under the nitrogen atmosphere. The fully reacted 2-chloroethylamine hydrochloride/ethanol solution was added dropwise to the 1-vinylimidazole/ethanol solution (volume ratio 1:1) and the reaction was continued at room temperature for 16 hours. Finally, the ethanol was removed by continuous drying under vacuum at high temperature for 2 hours. The product was washed repeatedly with ethyl acetate to reach constant weight. The pH of the mixture was adjusted to 8 by addition of 3M aqueous KOH. Subsequently, an amino-vinyl bifunctional imidazole ionic liquid with a Cl element ([ Cl ] was obtained by recrystallization in ethanol]VIm-NH ₂ ). The obtained [ Cl ]]VIm-NH ₂ And a LiTFSI salt were dissolved in water, respectively, to give a 40wt% solution. Dripping the aqueous solution of LiTFSI into [ Cl ]]VIm-NH ₂ Anion exchange in aqueous solution and stirring at room temperature for 16 hours to allow [ Cl]Exchange to anions in lithium salts of alkali metals [ TFSI]. The crude product was thoroughly washed with distilled water to remove excess lithium salt. Product VIm-NH ₂ [TFSI]Fully drying under vacuum condition to be used as bifunctional ionic liquid monomer for standby.

(1) Unsaturated ester polyethylene glycol diacrylate (PEGDA), photoinitiator diphenyl (2,4,6 Trimethylbenzoyl) Phosphine Oxide (TPO), and cross-linking agent pentaerythritolAlcohol tetramercaptoacetate (PETMP) and bifunctional ionic liquid monomer (VIm-NH) ₂ [TFSI]) And lithium bistrifluoromethanesulfonimide (LiTFSI) was previously dried in a vacuum oven.

(2) The PEGDA and the LiTFSI (EO ratio of 18) are added into a screw bottle in a glove box, and stirred for 2.5h (rotation speed of 600 r/min) at a constant temperature of 50 ℃ until the lithium salt is completely dissolved.

(3) And (3) adding PETMP into the solution obtained in the step (2) (the mass ratio is 2.5%), and stirring for 1.5 hours at the constant temperature of 50 ℃ (the rotating speed is 600 r/min) until the solution is uniform and transparent.

(4) Simultaneously, TPO and VIm-NH were mixed in a glove box ₂ [TFSI](the mass ratio is 1.

(5) And (3) adding the solutions obtained in the steps (3) and (4) into a screw bottle (the volume ratio is 2:1), and stirring for 1h (the rotating speed is 400 r/min) in a dark place at the constant temperature of 50 ℃ until the system is uniformly mixed.

(6) And (4) putting the mixed solution obtained in the step (5) into a glove box transition cabin, vacuumizing, carrying out ultrasonic treatment for 0.5h in a dark place, and removing bubbles in the mixed solution. And (3) casting the precursor solution into a PTFE plate, irradiating the PTFE plate for 1 hour under ultraviolet light until the surface of the solution has no flow sign, and then putting the solution into a vacuum drying oven at 80 ℃ for overnight drying to obtain the elastomer solid electrolyte.

(7) Cutting the all-solid-state electrolyte material in the step (6) into a disc shape with the diameter of 16mm, and assembling the disc shape into a battery in a glove box filled with argon.

(8) The preparation method of the lithium ion battery of the embodiment is as follows: s1: dissolving 50g of positive electrode materials (LFP, LCO and LRO), 4.2g of conductive carbon black, 7.3g of precursor liquid obtained in the step (5) 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 obtaining a positive plate after ultraviolet irradiation, drying, rolling and slitting; s2: and preparing a solid lithium ion battery cell from the obtained positive plate, the solid electrolyte and the negative electrode Li plate in a lamination mode, and packaging to obtain the lithium ion battery.

For the product VIm-NH prepared above ₂ [TFSI]Performing nuclear magnetic detection to obtain nucleiThe magnetic H spectrum is shown in FIG. 1, from which it can be seen that the product VIm-NH ₂ [TFSI]The ionic liquid has two functional groups of alkenyl-amino for designing the structure, and can be used as a bifunctional ionic liquid monomer.

Product VIm-NH ₂ [TFSI]The physical representation of (A) is shown in FIG. 2. From FIG. 2, it can be seen that the product VIm-NH ₂ [TFSI]Is a clear liquid.

Example 2:

1-vinylimidazole and ethanol were charged in a mass ratio of 1.5 into a four-necked flask equipped with a reflux condenser, and sufficiently stirred at room temperature for 1 hour. Then, 2-chloroethylamine hydrochloride and ethanol are mixed in a beaker according to the mass ratio of 1.5, and then stirred and refluxed for 1 hour at 70 ℃ under the nitrogen atmosphere. The 2-chloroethylamine hydrochloride/ethanol solution which had completely reacted was added dropwise to the 1-vinylimidazole/ethanol solution (volume ratio 1.5), and then the reaction was continued at room temperature for 16 hours. Finally, the ethanol was removed by drying under vacuum at high temperature for 4 hours. The product was washed repeatedly with ethyl acetate to reach constant weight. The pH of the mixture was adjusted to 7 by the addition of 3M aqueous KOH. Subsequently, an amino-vinyl bifunctional imidazole ionic liquid with a Cl element ([ Cl ] was obtained by recrystallization in ethanol]VIm-NH ₂ ). The [ Cl ] obtained]VIm-NH ₂ And the LiTFSI salt were dissolved in water, respectively, to give a 50wt% solution. Dripping the aqueous solution of LiTFSI into [ Cl ]]VIm-NH ₂ Anion exchange in aqueous solution and stirring at room temperature for 16 hours to allow [ Cl]Exchange into anions of lithium salts of alkali metals [ TFSI]. The crude product was thoroughly washed with distilled water to remove excess lithium salt. The product VIm-NH ₂ [TFSI]Drying thoroughly under vacuum.

(1) Unsaturated ester polyethylene glycol diacrylate (PEGDA), photoinitiator diphenyl (2,4,6 Trimethylbenzoyl) Phosphine Oxide (TPO), cross-linking agent pentaerythritol tetramercaptoacetate (PETMP), bifunctional ionic liquid monomer (VIm-NH 2[ TFSI ]) and lithium bistrifluoromethanesulfonylimide (LiTFSI) are pre-dried in a vacuum oven.

(3) And (3) adding PETMP into the solution in the step (2) (the mass ratio is 2.5%), and stirring for 1.5 hours (the rotating speed is 600 r/min) at the constant temperature of 50 ℃ until the solution is uniform and transparent.

(7) And (4) cutting the all-solid-state electrolyte material in the step (6) into a disc shape with the diameter of 16mm, and assembling the disc-shaped all-solid-state electrolyte material into a battery in a glove box filled with argon.

(8) The preparation method of the lithium ion battery of this embodiment is the same as that of embodiment 1, and is not described herein again.

Example 3:

1-vinyl imidazole and ethanol were charged in a mass ratio of 1:2 in a four-necked flask with a reflux condenser, and first stirred well at room temperature for 1 hour. Then mixing the 2-chloroethylamine hydrochloride and the ethanol according to the mass ratio of 1:2 in a beaker, and then stirring and refluxing for 2 hours at 70 ℃ in a nitrogen atmosphere. The fully reacted 2-chloroethylamine hydrochloride/ethanol solution was added dropwise to the 1-vinylimidazole/ethanol solution (volume ratio 1:2) and the reaction was continued at room temperature for 16 hours. Finally, the ethanol was removed by continuous drying under vacuum at high temperature for 5 hours. The product was washed repeatedly with ethyl acetate and acetone to reach constant weight. The pH of the mixture was adjusted to 7.5 by the addition of 3M aqueous KOH. Subsequently, an amino-vinyl bifunctional imidazolium ionic liquid ([ Cl ] with Cl element) was obtained by recrystallization in ethanol]VIm-NH ₂ ). The obtained [ Cl ]]VIm-NH ₂ And the LiTFSI salt were dissolved in water, respectively, to give a 45wt% solution. Dripping the aqueous solution of LiTFSI into [ Cl ]]VIm-NH ₂ Anion exchange in aqueous solution and stirring at room temperature for 16 hours to allow [ Cl]Exchange into anions of lithium salts of alkali metals [ TFSI]. The crude product was thoroughly washed with distilled water to remove excess lithium salt. Product VIm-NH ₂ [TFSI]Drying thoroughly under vacuum.

(1) Unsaturated ester polyethylene glycol diacrylate (PEGDA), photoinitiator diphenyl (2,4,6 Trimethylbenzoyl) Phosphine Oxide (TPO), cross-linking agent pentaerythritol tetramercaptoacetate (PETMP), and bifunctional ionic liquid monomer (VIm-NH) ₂ [TFSI]) And lithium bistrifluoromethanesulfonimide (LiTFSI) was previously dried in a vacuum oven.

(4) Meanwhile, TPO and VIm-NH2[ TFSI ] (mass ratio is 1: 50) are added into a screw bottle in a glove box, and stirred for 3h (rotating speed is 600 r/min) under the conditions of constant temperature of 50 ℃ and light shielding until TPO is completely dissolved.

Example 4:

1-vinylimidazole and ethanol were charged in a mass ratio of 1:2.5 into a four-necked flask with a reflux condenser, and stirred thoroughly at room temperature for 2 hours. Then, 2-chloroethylamine hydrochloride and ethanol are mixed in a beaker according to the mass ratio of 1. The 2-chloroethylamine hydrochloride/ethanol solution which had completely reacted was added dropwise to the 1-vinylimidazole/ethanol solution (volume ratio 1: 2.5), and then the reaction was continued at room temperature for 16 hours. Finally, the ethanol was removed by continuous drying under vacuum at high temperature for 5 hours. The product was washed repeatedly with ethyl acetate and acetone to reach constant weight. The pH of the mixture was adjusted to 8 by the addition of 3M aqueous KOH. Subsequently, an amino-vinyl bifunctional imidazole ionic liquid with a Cl element ([ Cl ] was obtained by recrystallization in ethanol]VIm-NH ₂ ). The obtained [ Cl ]]VIm-NH ₂ And the LiTFSI salt were dissolved in water, respectively, to give a 50wt% solution. Dripping the aqueous solution of LiTFSI into [ Cl ]]VIm-NH ₂ Anion exchange in aqueous solution and stirring at room temperature for 16 hours to allow [ Cl]Exchange into anions of lithium salts of alkali metals [ TFSI]. The crude product was thoroughly washed with distilled water to remove excess lithium salt. Product VIm-NH2[ TFSI]Drying thoroughly under vacuum.

(4) At the same time, in a glove boxIn the reaction of TPO and VIm-NH ₂ [TFSI](the mass ratio is 1.

(5) Adding the solutions obtained in the steps (3) and (4) into a screw bottle (the volume ratio is 2:1), and stirring for 1h (the rotating speed is 400 r/min) in a dark place at the constant temperature of 50 ℃ until the system is uniformly mixed.

Example 5:

1-vinyl imidazole and ethanol were charged in a mass ratio of 1:3 in a four-necked flask with a reflux condenser, and first stirred well at room temperature for 2 hours. Then mixing the 2-chloroethylamine hydrochloride and the ethanol according to the mass ratio of 1:3 in a beaker, and then stirring and refluxing for 3 hours at 70 ℃ in a nitrogen atmosphere. The fully reacted 2-chloroethylamine hydrochloride/ethanol solution was added dropwise to the 1-vinylimidazole/ethanol solution (volume ratio 1:3) and the reaction was continued at room temperature for 16 hours. Finally, the ethanol was removed by continuous drying under vacuum at high temperature for 5 hours. The product was washed repeatedly with ethyl acetate and acetone to reach constant weight. The pH of the mixture was adjusted to 8 by addition of 3M aqueous KOH. Subsequently, an amino-vinyl bifunctional imidazole ionic liquid with a Cl element ([ Cl ] was obtained by recrystallization in ethanol]VIm-NH ₂ ). The obtained [ Cl ]]VIm-NH ₂ And the LiTFSI salt were dissolved in water, respectively, to give a 50wt% solution. Dripping the aqueous solution of LiTFSI into [ Cl ]]VIm-NH ₂ Anion exchange in aqueous solution and stirring at room temperature for 16 hours to allow [ Cl]Exchange into anions in alkali metal lithium saltsSeed [ TFSI ]]. The crude product was thoroughly washed with distilled water to remove excess lithium salt. Product VIm-NH ₂ [TFSI]Drying thoroughly under vacuum.

Comparative example 1:

this example VIm-NH ₂ [TFSI]The preparation method is the same as that of example 1, and is not repeated herein.

(1) Polyethylene glycol methyl ether acrylate, photoinitiator diphenyl (2,4,6 Trimethylbenzoyl) Phosphine Oxide (TPO), cross-linking agent trimethylolpropane tris (3-mercaptopropionate) (TMPMP), and bifunctional ionic liquid monomer (VIm-NH) ₂ [TFSI]) And lithium bistrifluoromethanesulfonimide (LiTFSI) was previously dried in a vacuum oven.

(2) Adding polyethylene glycol methyl ether acrylate and LiTFSI (EO ratio of 20) into a screw-top bottle in a glove box, and stirring for 2.5h (rotating speed of 600 r/min) at constant temperature of 50 ℃ until the lithium salt is completely dissolved.

(3) And adding TMPMP into the solution obtained in the step (2) (the mass ratio is 3%), and stirring for 1.5 hours at the constant temperature of 50 ℃ (the rotating speed is 600 r/min) until the solution is uniform and transparent.

(5) And (3) adding the solutions obtained in the steps (3) and (4) into a screw bottle (the volume ratio is 2.5.

(6) And (5) putting the mixed solution in the step (5) into a glove box transition cabin, vacuumizing, carrying out ultrasonic treatment for 1 hour in a dark place, and removing bubbles in the mixed solution. And (3) casting the precursor solution into a PTFE plate, irradiating the PTFE plate for 2 hours under ultraviolet light until the surface of the solution has no flow sign, and then putting the solution into a vacuum drying oven at 80 ℃ for overnight drying to obtain the elastomer solid electrolyte.

(8) The preparation method of the lithium ion battery of this embodiment is the same as that of embodiment 1, and is not repeated herein.

Comparative example 2:

this example VIm-NH ₂ [TFSI]The preparation method is the same as that of example 2, and the details are not repeated here

(1) Polyethylene glycol methyl ether acrylate, photoinitiator diphenyl (2,4,6 Trimethylbenzoyl) Phosphine Oxide (TPO)) Trimethylolpropane tris (3-mercaptopropionate) (TMPMP) serving as a crosslinking agent and bifunctional ionic liquid monomer (VIm-NH) ₂ [TFSI]) And lithium bistrifluoromethanesulfonimide (LiTFSI) was previously dried in a vacuum oven.

Comparative example 3:

the preparation method of VIm-NH2[ TFSI ] in this example is the same as that in example 3, and is not repeated here

(1) Polyethylene glycol methyl ether acrylate, photoinitiator diphenyl (2,4,6 Trimethylbenzoyl) Phosphine Oxide (TPO), cross-linking agent trimethylolpropane tris (3-mercaptopropionate) (TMPMP), and bifunctional ionic liquid monomer (VIm-NH) ₂ [TFSI]) And bis (trifluoromethanesulfonylidine)Lithium amide (LiTFSI) was pre-dried in a vacuum oven.

Comparative example 4:

the preparation method of VIm-NH2[ TFSI ] in this example is the same as that in example 4, and is not repeated here

(6) And (5) putting the mixed solution in the step (5) into a glove box transition cabin, vacuumizing, carrying out ultrasonic treatment for 1 hour in a dark place, and removing bubbles in the mixed solution. And (3) casting the precursor solution into a PTFE plate, irradiating the PTFE plate for 2 hours under ultraviolet light until the surface of the solution has no flow sign, and then putting the PTFE plate into a vacuum drying oven at 80 ℃ for overnight drying to obtain the elastomer solid electrolyte.

Comparative example 5:

the preparation method of VIm-NH2[ TFSI ] in this example is the same as that in example 5, and is not repeated here

Example 6:

1-vinyl imidazole and ethanol in a mass ratio of 1:1 were charged into a four-necked flask equipped with a reflux condenser, and first stirred well at room temperature for 0.5 hour. Then mixing the 2-chloroethylamine hydrochloride and the ethanol according to the mass ratio of 1:1 in a beaker, and then stirring and refluxing for 0.5 hour at 70 ℃ under the nitrogen atmosphere. The fully reacted 2-chloroethylamine hydrochloride/ethanol solution was added dropwise to the 1-vinylimidazole/ethanol solution (volume ratio 1:1) and the reaction was continued at room temperature for 16 hours. Finally, the ethanol was removed by continuous drying under vacuum at high temperature for 2 hours. The product was washed repeatedly with ethyl acetate to reach constant weight. The pH of the mixture was adjusted to 8 by the addition of 3M aqueous KOH. Subsequently, an amino-vinyl bifunctional imidazole ionic liquid with a Cl element ([ Cl ] was obtained by recrystallization in ethanol]VIm-NH ₂ ). The obtained [ Cl ]]VIm-NH ₂ And LiThe FSI salts were dissolved in water to give 50wt% solutions. Dropping LiFSI aqueous solution into [ Cl]VIm-NH ₂ Anion exchange in aqueous solution and stirring at room temperature for 16 hours to allow [ Cl]By exchange for anions of lithium salts of alkali metals [ FSI]. The crude product was thoroughly washed with distilled water to remove excess lithium salt. The product VIm-NH ₂ [FSI]Drying thoroughly under vacuum.

(1) Unsaturated ester polyethylene glycol diacrylate (PEGDA), photoinitiator diphenyl (2,4,6 Trimethylbenzoyl) Phosphine Oxide (TPO), cross-linking agent pentaerythritol tetramercaptoacetate (PETMP), bifunctional ionic liquid monomer (VIm-NH) ₂ [FSI]) And LiFSI pre-drying treatment in a vacuum oven.

(2) PEGDA and LiFSI (EO ratio of 20) are added into a screw-top bottle in a glove box, and stirred for 2.5h (rotation speed of 600 r/min) at a constant temperature of 50 ℃ until the lithium salt is completely dissolved.

(4) Simultaneously, TPO and VIm-NH were mixed in a glove box ₂ [FSI](the mass ratio is 1.

Example 7:

1-vinyl imidazole and ethanol in a mass ratio of 1:1 were charged into a four-necked flask equipped with a reflux condenser, and first stirred well at room temperature for 0.5 hour. Then mixing the 2-chloroethylamine hydrochloride and the ethanol according to the mass ratio of 1:1 in a beaker, and then stirring and refluxing for 0.5 hour at 70 ℃ under the nitrogen atmosphere. The fully reacted 2-chloroethylamine hydrochloride/ethanol solution was added dropwise to the 1-vinylimidazole/ethanol solution (volume ratio 1:1) and the reaction was continued at room temperature for 16 hours. Finally, the ethanol was removed by continuous drying under vacuum at high temperature for 2 hours. The product was washed repeatedly with ethyl acetate to reach constant weight. The pH of the mixture was adjusted to 8 by addition of 3M aqueous KOH. Subsequently, an amino-vinyl bifunctional imidazole ionic liquid with a Cl element ([ Cl ] was obtained by recrystallization in ethanol]VIm-NH ₂ ). The obtained [ Cl ]]VIm-NH ₂ And LiBOB salt were dissolved in water, respectively, to obtain a 50wt% solution. Dripping LiBOB aqueous solution into [ Cl]VIm-NH ₂ Anion exchange in aqueous solution and stirring at room temperature for 16 hours to allow [ Cl]Exchange into anions [ BOB ] in lithium salts of alkali metals]. The crude product was thoroughly washed with distilled water to remove excess lithium salt. Product VIm-NH ₂ [BOB]Drying thoroughly under vacuum.

(1) Unsaturated ester polyethylene glycol diacrylate (PEGDA), photoinitiator diphenyl (2,4,6 Trimethylbenzoyl) Phosphine Oxide (TPO), cross-linking agent pentaerythritol tetramercaptoacetate (PETMP), and bifunctional ionic liquid monomer (VIm-NH) ₂ [BOB]) And LiBOB is pre-dried in a vacuum oven.

(2) The PEGDA and LiBOB (EO ratio of 20) were added to a screw bottle in a glove box and stirred at a constant temperature of 50 ℃ for 2.5 hours (600 r/min) until the lithium salt was completely dissolved.

(4) Simultaneously, TPO and VIm-NH were mixed in a glove box ₂ [BOB](the mass ratio is 1600 r/min) until TPO is completely dissolved.

Comparative example 6:

this example VIm-NH ₂ [FSI]The preparation method is the same as that of example 6, and the details are not repeated herein

(1) Polyethylene glycol methyl ether acrylate, photoinitiator diphenyl (2,4,6 Trimethylbenzoyl) Phosphine Oxide (TPO), cross-linking agent trimethylolpropane tris (3-mercaptopropionate) (TMPMP), and bifunctional ionic liquid monomer (VIm-NH) ₂ [FSI]) And LiFSI is pre-dried in a vacuum oven.

(2) Adding polyethylene glycol methyl ether acrylate and LiFSI (EO ratio of 20) into a screw-top bottle in a glove box, and stirring for 2.5h (rotating speed of 600 r/min) at a constant temperature of 50 ℃ until lithium salt is completely dissolved.

Comparative example 7:

this example VIm-NH ₂ [BOB]The preparation method is the same as that of example 7, and the details are not repeated herein

(1) Polyethylene glycol methyl ether acrylate, a photoinitiator diphenyl (2,4,6 Trimethylbenzoyl) Phosphine Oxide (TPO), a cross-linking agent trimethylolpropane tris (3-mercaptopropionate) (TMPMP), and a bifunctional ionic liquid monomer (VIm-NH) ₂ [BOB]) And LiBOB is pre-dried in a vacuum oven.

(2) Adding polyethylene glycol methyl ether acrylate and LiBOB (EO ratio is 20) into a screw-top bottle in a glove box, and stirring for 2.5h (rotation speed is 600 r/min) at the constant temperature of 50 ℃ until the lithium salt is completely dissolved.

(4) Simultaneously, TPO and VIm-NH were mixed in a glove box ₂ [BOB](the mass ratio is 1.

The physical representation of the all-solid electrolyte is shown in FIG. 3, which shows the electrolyte that has been cut into disks, which can be seen as a milky white film.

The results of SEM examination of the all-solid electrolyte are shown in fig. 4, and it can be seen from fig. 4 that the all-solid electrolyte thin film has a uniform texture and a flat and smooth film layer.

Example 8:

1-vinyl imidazole and ethanol in a mass ratio of 1:1 were charged into a four-necked flask equipped with a reflux condenser, and first stirred well at room temperature for 0.5 hour. Then mixing the 2-chloroethylamine hydrochloride and the ethanol according to the mass ratio of 1:1 in a beaker, and then stirring and refluxing for 0.5 hour at 70 ℃ under the nitrogen atmosphere. The fully reacted 2-chloroethylamine hydrochloride/ethanol solution was added dropwise to the 1-vinylimidazole/ethanol solution (volume ratio 1:1) and the reaction was continued at room temperature for 16 hours. Finally, the ethanol was removed by continuous drying under vacuum at high temperature for 2 hours. The product was washed repeatedly with ethyl acetate to reach constant weight. The pH of the mixture was adjusted to 8 by addition of 3M aqueous KOH. Subsequently, an amino-vinyl bifunctional imidazole ionic liquid with a Cl element ([ Cl ] was obtained by recrystallization in ethanol]VIm-NH ₂ ). The obtained [ Cl ]]VIm-NH ₂ And LiFSI salt were dissolved in water, respectively, to obtain a 50wt% solution. Dropping LiFSI aqueous solution into [ Cl]VIm-NH ₂ Anion exchange in aqueous solution and stirring at room temperature for 16 hours to allow [ Cl]By exchange for anions of lithium salts of alkali metals [ FSI]. The crude product was thoroughly washed with distilled water to remove excess lithium salt. Product VIm-NH ₂ [FSI]Under vacuumDrying fully under the condition.

(1) Ethyl 2-cyanoacrylate, diphenyl photoinitiator (2,4,6 Trimethylbenzoyl) Phosphine Oxide (TPO), pentaerythritol tetramercapto acetate (PETMP) serving as a cross-linking agent, and a bifunctional ionic liquid monomer (VIm-NH) ₂ [FSI]) And LiFSI pre-drying treatment in a vacuum oven.

(2) Adding the ethyl 2-cyanoacrylate and LiFSI (EO ratio of 20) into a screw-top bottle in a glove box, and stirring for 2.5 hours (rotating speed of 600 r/min) at a constant temperature of 50 ℃ until the lithium salt is completely dissolved.

The elastomer solid electrolytes prepared in the above examples and comparative examples, i.e., the products of step (6), were subjected to physical parameter measurements, and the characterization results are shown in table 1.

TABLE 1 characterization of physical parameters of elastomer solid electrolyte

As can be seen from table 1, the molecular weight of the elastomer solid electrolyte is 10000 to 100000; the crystallinity is 10 to 65 percent; the thermal decomposition temperature is 250-550 ℃; the elastic modulus is 100-510%. When the unsaturated ester monomer adopts polyethylene glycol diacrylate, the crystallinity of the product is low, and the mechanical property is good. When LiTFSI is used as the alkali metal salt, the elastic deformation of the product is improved.

The elastomer solid electrolytes prepared in the above examples and comparative examples were subjected to mechanical property tests, and the test results are shown in table 2.

TABLE 2 table of the results of mechanical property test of elastomer solid electrolyte

As can be seen from table 2, the shore hardness of the elastomer solid electrolyte was 10-50A; young modulus is 1-20GPa; the tensile strength is 1-40MPa. When the unsaturated ester monomer adopts polyethylene glycol diacrylate, the hardness of the product is moderate, and the modulus is better. When the alkali metal salt adopts LiTFSI, the glass transition temperature of the product is lower, which is beneficial to the migration of ions.

The batteries prepared in the above examples and comparative examples were subjected to tests for solid electrolyte ionic conductivity and cycle performance of lithium ion batteries. The test results are shown in Table 3.

TABLE 3 Battery test results Table

As can be seen from the data in table 3, the adaptive elastomeric polymer electrolyte of the present invention has higher room temperature ionic conductivity, excellent interfacial properties, and the lithium ion battery assembled using the solid electrolyte of the present invention has better cycle performance. Taking example 1 and comparative example 1 as examples, neglecting the slight difference of the cross-linking agent, compared with the solid electrolyte prepared by polymerization prepared by using unsaturated ester polyethylene glycol diacrylate (PEGDA) in example 1 and polyethylene glycol methyl ether acrylate in comparative example 1, the mechanical property is improved, but the lithium conductivity is poor, and the cycle performance of the assembled solid battery is poor.

The comparison between examples 2 to 7 and their corresponding comparative examples corresponds to that between example 1 and comparative example 1, and no additional analysis is carried out here.

In comparison with example 6, comparative example 6 and example 1, the lithium salt used in example 1 was LiTFSI, and in example 6 and comparative example 6, liFSI was used, and the electrolytes prepared in example 6 and comparative example 6 had relatively low conductivities, resulting in excessively rapid capacity fade of the solid-state battery.

Example 1 compared to example 8, when the solid electrolyte prepared by polymerization prepared by using ethyl 2-cyanoacrylate was used in preparing the solid electrolyte, the ion conductivity of the solid electrolyte and the cycle performance of the lithium ion battery were slightly superior to those of the polymer solid electrolyte prepared by PEGDA and the lithium ion battery.

Fig. 5 is a cross-sectional SEM image of the battery prepared in example 4 after charge and discharge cycles, and it can be seen from fig. 5 that the electrode/electrolyte interface contact remains tightly attached and no dendrite occurs after completing 500 cycles due to the excellent self-adaptability and mechanical properties of the polymer electrolyte.

Example 9

1-allyl imidazole and ethanol according to the weight ratio of 1:1 into with a reflux condenser four neck flask, first room temperature fully stirred for 0.5 hours. Then 2-chloroethylamine hydrochloride and ethanol are mixed in a beaker according to the mass ratio of 1:1, and then the mixture is stirred and refluxed for 0.5 hour at the temperature of 65 ℃ under the nitrogen atmosphere.The 2-chloroethylamine hydrochloride/ethanol solution which had completely reacted was added dropwise to the 1-propenyl imidazole/ethanol solution (volume ratio 1:1), and the reaction was continued at room temperature for 16 hours. Finally, the ethanol was removed by continuous drying under vacuum at high temperature for 2 hours. The product was washed repeatedly with ethyl acetate to reach constant weight. The pH of the mixture was adjusted to 8 by the addition of 3M aqueous KOH. Subsequently, an amino-propenyl bifunctional imidazole ionic liquid with a Cl element ([ Cl ] was obtained by recrystallization in ethanol]VIm-NH ₂ ). The obtained [ Cl ]]VIm-NH ₂ And the LiTFSI salt were dissolved in water, respectively, to give a 50wt% solution. Dripping the aqueous solution of LiTFSI into [ Cl ]]VIm-NH ₂ Anion exchange in aqueous solution and stirring at room temperature for 16 hours to allow [ Cl]Exchange into anions of lithium salts of alkali metals [ TFSI]. The crude product was thoroughly washed with distilled water to remove excess lithium salt. Product VIm-NH ₂ [TFSI]Drying thoroughly under vacuum.

(1) Unsaturated ester methyl methacrylate, photoinitiator diphenyl (2,4,6-Trimethylbenzoyl) Phosphine Oxide (TPO), cross-linking agent pentaerythritol tetramercaptoacetate (PETMP), and bifunctional ionic liquid monomer (VIm-NH) ₂ [TFSI]) And lithium bistrifluoromethanesulfonimide (LiTFSI) was previously dried in a vacuum oven.

(2) The methyl methacrylate and LiTFSI (EO ratio of 18) were added to a screw bottle in a glove box and stirred at a constant temperature of 50 ℃ for 2.5 hours (600 r/min) until the lithium salt was completely dissolved.

Example 10

1-allyl imidazole and ethanol according to the weight ratio of 1:1 into with a reflux condenser four neck flask, first room temperature fully stirred for 0.5 hours. Then mixing 2-bromoethylamine hydrobromide and ethanol according to the mass ratio of 1:1 in a beaker, and then stirring and refluxing for 0.5 hour at the temperature of 65 ℃ under the atmosphere of nitrogen. The fully reacted 2-bromoethylamine hydrobromide/ethanol solution was added dropwise to the 1-propenyl imidazole/ethanol solution (volume ratio 1:1) and the reaction was continued at room temperature for 16 hours. Finally, the ethanol was removed by continuous drying under vacuum at high temperature for 2 hours. The product was washed repeatedly with ethyl acetate to reach constant weight. The pH of the mixture was adjusted to 8 by addition of 3M aqueous KOH. Subsequently, an amino-propenyl bifunctional imidazole ionic liquid with Br element ([ Br ]) was obtained by recrystallization in ethanol]VIm-NH ₂ ). Reacting the obtained [ Br ]]VIm-NH ₂ And the LiTFSI salt were dissolved in water, respectively, to give a 50wt% solution. Dripping LiTFSI aqueous solution into [ Br ]]VIm-NH ₂ Anion exchange was carried out in aqueous solution and stirring was continued at room temperature for 16 hours to allow [ Br ]]Exchange to anions in lithium salts of alkali metals [ TFSI]. The crude product was thoroughly washed with distilled water to remove excess lithium salt. Product VIm-NH ₂ [TFSI]Drying thoroughly under vacuum.

(1) Unsaturated ester tripropylene glycol diacrylate, photoinitiator diphenyl (2,4,6-Trimethylbenzoyl) Phosphine Oxide (TPO), cross-linking agent (mercapto) propyl methyl siloxane, bifunctional ionic liquid monomer (VIm-NH) ₂ [TFSI]) And lithium bistrifluoromethanesulfonimide (LiTFSI) was previously dried in a vacuum oven.

(2) Tripropylene glycol diacrylate and LiTFSI (EO ratio of 18) are added into a screw bottle in a glove box, and stirred for 2.5 hours (rotating speed of 600 r/min) at a constant temperature of 50 ℃ until the lithium salt is completely dissolved.

(3) And (mercapto) propyl methyl siloxane is added into the solution in the step (2) (the mass ratio is 5 percent), and the solution is stirred for 1.5 hours (the rotating speed is 600 r/min) at the constant temperature of 50 ℃ until the solution is uniform and transparent.

The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.

It should be noted that the various features described in the above embodiments may be combined in any suitable manner without departing from the scope of the invention. The invention is not described in detail in order to avoid unnecessary repetition.

In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.

Claims

1. A preparation method of bifunctional ionic liquid is characterized in that: the method comprises the following steps:

(5) Subjecting the obtained [ X ] to]VIm-NH ₂ And alkali metal lithium salt are respectively added into water, then mixed and continuously stirred to carry out anion exchange, so that [ X ] in the ionic liquid]By exchange for anions [ Y ] in lithium alkali metal salts]Obtaining the difunctional ionic liquid VIm-NH ₂ [Y]。

2. The method for preparing the bifunctional ionic liquid according to claim 1, wherein: the alkenyl imidazole is any one of 1-vinyl imidazole, 1-allyl-3-methyl imidazole chloride or 1-allyl-3-methyl imidazole;

3. A method of preparing a bifunctional ionic liquid as claimed in claim 1 or 2, characterized in that: the mass ratio of the alkenylimidazole to the solvent is 1:1-1:5, preferably 1:2-1:3;

optionally, the mass ratio of the reaction solution to the alkenyl imidazole solution in step (3) is 1:0.2-1.5, mixing the two, reacting, drying to remove the solvent after the reaction is finished, and repeatedly washing the product with one or more of ethyl acetate, acetone and methanol to make the product reach constant weight to obtain a solid;

4. The bifunctional ionic liquid prepared by the preparation method of any one of claims 1-3.

5. An adaptively deformable elastomer electrolyte, comprising: the preparation method comprises the following steps: mixing an unsaturated ester monomer, the bifunctional ionic liquid as defined in claim 4, an alkali metal salt, an initiator and a cross-linking agent, and curing the obtained precursor solution under the ultraviolet irradiation condition to obtain the self-adaptively deformable elastomer electrolyte;

preferably, the preparation method comprises the following steps:

s1, adding the alkali metal lithium salt into the unsaturated ester monomer, fully stirring under a protective gas atmosphere to completely dissolve the alkali metal lithium salt, then adding the cross-linking agent, and uniformly stirring to obtain a solution A;

6. An adaptively deformable elastomer electrolyte as defined in claim 5, wherein: the unsaturated ester monomer is at least one of polyethylene glycol diacrylate, n-butyl acrylate, methyl methacrylate, vinyl acetate, vinylene carbonate, ethylene carbonate, 2-ethyl cyanoacrylate, polyethylene glycol methyl ether acrylate, methyl ethyl-methyl cyanoacrylate, ethoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate, ditrimethylolpropane tetraacrylate, 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, hydroxyethyl acrylate and derivatives thereof; preferably, the unsaturated ester monomer is at least one of polyethylene glycol diacrylate and polyethylene glycol methyl ether acrylate;

optionally, the alkali metal salt is LiAsF ₆ 、LiDFOB、LiBOB、LiCF ₃ SO ₃ 、LiN(CF ₃ SO ₂ ) ₂ 、LiN(C ₂ F ₅ SO ₂ ) ₂ 、LiPF ₆ 、LiN(CF ₃ SO ₂ )(C ₄ F ₉ SO ₂ )、LiTDI、LiC(CF ₃ SO ₂ ) ₃ 、LiBF ₄ 、LiC(C ₂ F ₅ SO ₂ ) ₃ 、LiClO ₄ At least one of (a) and (b); preferably, the alkali metal salt is at least one of LiTFSI, liFSI, liBOB;

optionally, the initiator is a photoinitiator, preferably a free radical photoinitiator or a cationic photoinitiator, wherein: the free radical photoinitiator is preferably at least one of dialkoxyacetophenone, alpha-hydroxyalkylphenone, acylphosphine oxide, benzoins, diphenyl (2,4,6 trimethylbenzoyl) phosphine oxide, 2-methyl 1 (4 methylthiophenyl) 2 morpholine 1 acetone, 2-hydroxy-2-methylphenylpropane-1-one; the cationic photoinitiator is preferably at least one of onium salts, metallorganics, organosilanes, diaryliodonium salts, triarylsulfonium salts and arylferrocenium salts; optionally, the cross-linking agent is at least one of pentaerythritol tetramercaptoacetate, trimethylolpropane tris (3-mercaptopropionate), trimethylolpropane tris (2-mercaptoacetate)), pentaerythritol tetrakis (mercaptoacetate), (mercapto) propylmethylsiloxane, and derivatives thereof.

7. An adaptively deformable elastomeric electrolyte as defined in claim 5 or 6, wherein: the adding amount of the alkali metal lithium salt in the S1 is 10-50% of the mass of the unsaturated ester monomer, and the adding amount of the cross-linking agent is 1-10% of the mass of the unsaturated ester monomer;

8. An adaptively deformable elastomeric electrolyte as defined in claim 5 or 6, wherein: the molecular weight of the self-adaptive deformation elastomer electrolyte is 10000-100000, preferably 40000-50000; the crystallinity is 10 to 65 percent, preferably 20 to 30 percent; the thermal decomposition temperature is 250-550 ℃, preferably 300-400 ℃; the elastic modulus is 100-510%, preferably 200-300%; shore hardness is 10-50A, preferably 20-30A; young's modulus of 1-20GPa, preferably 10-15GPa; the tensile strength is 1-40MPa, preferably 30-40MPa; the conductivity is from 0.2 to 2.5mS/cm, preferably from 2.0 to 2.5mS/cm.

9. An electrode comprising the adaptively deformable elastomeric electrolyte of any of claims 5-8, wherein: the preparation method comprises the steps of coating a mixed solution consisting of an active material, a conductive agent, a bonding agent and the precursor solution of claim 5 on the surface of a metal current collector, and obtaining the electrode after ultraviolet irradiation, drying, rolling and slitting; preferably, the active material is lithium cobaltate, lithium iron phosphate or a lithium-rich cathode material.

10. A battery comprising the electrode of claim 9, wherein: the number of cycles that the battery undergoes when its capacity decays to 80% of its first discharge capacity is 150-580, preferably 500-580.