阅读说明：本技术 一种自修复固态电解质及其制备方法、应用 (Self-repairing solid electrolyte and preparation method and application thereof ) 是由 徐林 左旭日 麦立强 于 2020-12-25 设计创作，主要内容包括：本发明提供了一种自修复固态电解质及其制备方法、应用,其制备方法具体步骤为：S1、将解离锂盐化合物与溶剂混合,超声得到解离液；S2、将自修复聚合物、交联剂、锂盐加入所述解离液中,混合均匀,升温反应获得自修复前驱体溶液；S3、将所述自修复前驱体溶液置于聚四氟乙烯板进行制膜,真空干燥,即得到自修复固态电解质。自修复固态电解质的制备过程简单、成本廉价易得、工艺绿色环保,且制得的自修复固态电解质具有稳定的自修复性能和优异的电化学性能。(The invention provides a self-repairing solid electrolyte and a preparation method and application thereof, wherein the preparation method comprises the following specific steps: s1, mixing the dissociated lithium salt compound with a solvent, and carrying out ultrasonic treatment to obtain a dissociation solution; s2, adding a self-repairing polymer, a cross-linking agent and lithium salt into the dissociation liquid, uniformly mixing, and heating to react to obtain a self-repairing precursor solution; s3, placing the self-repairing precursor solution on a polytetrafluoroethylene plate to prepare a membrane, and drying in vacuum to obtain the self-repairing solid electrolyte. The preparation process of the self-repairing solid electrolyte is simple, the cost is low, the self-repairing solid electrolyte is easy to obtain, the process is green and environment-friendly, and the prepared self-repairing solid electrolyte has stable self-repairing performance and excellent electrochemical performance.)

1. A preparation method of a self-repairing solid electrolyte is characterized by comprising the following specific steps:

s1, mixing the dissociated lithium salt compound with a solvent, and carrying out ultrasonic treatment to obtain a dissociation solution;

s2, adding a self-repairing polymer, a cross-linking agent and lithium salt into the dissociation liquid, uniformly mixing, and heating to react to obtain a self-repairing precursor solution;

s3, placing the self-repairing precursor solution on a polytetrafluoroethylene plate to prepare a membrane, and drying in vacuum to obtain the self-repairing solid electrolyte.

2. The method of claim 1, wherein in S1, the dissociated lithium salt compound comprises at least one of polyethylene glycol, polyvinylidene fluoride-hexafluoropropylene, polyethylene oxide, polypropylene carbonate, poly (ethylene glycol) methyl ether methacrylate, polyethylene carbonate, and polytrimethylene carbonate;

the solvent includes at least one of N-N dimethylformamide, tetrahydrofuran, N-methylpyrrolidone, N-N dimethylformamide, acetonitrile, acetone, and dimethyl sulfoxide.

3. The method for producing a self-healing solid electrolyte according to claim 1 or 2, wherein in S2, the self-healing polymer is DL- α -lipoic acid;

the lithium salt comprises at least one of lithium trifluoromethanesulfonylimide, lithium hexafluorophosphate, lithium perchlorate, lithium tetrafluoroborate, lithium nitrate, lithium difluorophosphate, lithium dioxalate borate, lithium hexafluoroarsenate, lithium difluorosulfonylimide and lithium difluorooxalateborate;

the crosslinking agent comprises a covalent crosslinking agent and a non-covalent crosslinking agent, and the covalent crosslinking agent comprises at least one of 1, 3-diisopropenyl benzene, ionic liquid containing mono-olefin and ionic liquid containing diene; the non-covalent crosslinking agent comprises a ferric salt.

4. The method for preparing the self-repairing solid electrolyte of claim 3, wherein the mass fraction of the dissociated lithium salt compound in the self-repairing solid electrolyte is 10-70%, the mass fraction of the self-repairing polymer is 40-80%, the mass fraction of the lithium salt is 5-50%, the mass fraction of the covalent crosslinking agent is 4.99-20%, and the mass fraction of the non-covalent crosslinking agent is 0.01-1%.

5. The method for preparing the self-repairing solid electrolyte of claim 1, wherein in S2, the temperature-raising reaction conditions include a reaction temperature of 50-90 ℃ and a reaction time of 40min-12 h.

6. The preparation method of the self-repairing solid electrolyte of claim 1, wherein in S2, the self-repairing polymer, the cross-linking agent, and the lithium salt are added to the dissociation solution, mixed uniformly, and subjected to a temperature-raising reaction to obtain a self-repairing precursor solution, specifically comprising the steps of:

s21, dissolving the lithium salt in the ionic liquid, and uniformly stirring to obtain a lithium salt mixed solution;

s22, adding the self-repairing polymer, the lithium salt mixed solution and the cross-linking agent into the dissociation solution, and heating to react to obtain a self-repairing precursor solution.

7. The method of producing a self-healing solid-state electrolyte according to claim 6, the ionic liquid includes at least one of 1-allyl-3-vinylimidazole bistrifluoromethylsulfonyl imide salt, 1-allyl-3-vinylimidazole tetrafluoroborate, 1-allyl-3-vinylimidazole hexafluorophosphate, 1-vinyl-3-butylimidazole bistrifluoromethylsulfonyl imide salt, 1-vinyl-3-butylimidazole tetrafluoroborate, 1-vinyl-3-butylimidazole hexafluorophosphate, 1-allyl-3-methylimidazole bistrifluoromethylsulfonyl imide salt, 1-allyl-3-methylimidazole tetrafluoroborate, and 1-allyl-3-methylimidazole hexafluorophosphate.

8. A self-repairing solid electrolyte prepared by the preparation method of the self-repairing solid electrolyte as claimed in any one of claims 1 to 7, wherein the self-repairing solid electrolyte comprises a self-repairing polymer, a dissociated lithium salt compound, a lithium salt and a cross-linking agent, and the dissociated lithium salt compound and the lithium salt are uniformly dispersed in the self-repairing solid electrolyte.

9. The self-healing solid-state electrolyte of claim 8, wherein the self-healing polymer comprises coordination, reversible covalent, and hydrogen bonds.

10. Use of the self-healing solid-state electrolyte according to claim 9, wherein the self-healing solid-state electrolyte is applied in the field of solid-state lithium batteries.

Technical Field

The invention relates to the technical field of solid-state batteries, in particular to a self-repairing solid electrolyte and a preparation method and application thereof.

Background

Lithium ion batteries are rapidly developed in the fields of portable electronic devices, electric vehicles, energy storage power systems and the like, and gradually occupy the leading position of the energy storage market. At present, the liquid electrolyte has high ionic conductivity and excellent wettability, and is absolutely superior in the electrolyte market of commercial lithium ion batteries, but the liquid electrolyte has many problems, including reaction of electrodes and electrolyte, inevitable lithium dendrite growth, unstable solid electrolyte membrane (SEI), and meanwhile, the flammability of the commercial electrolyte and penetration of lithium dendrite into a diaphragm have important influence on the safety problem of the battery. In recent years, solid-state batteries having better safety, higher energy density, and wider operating temperature range have been the focus of research.

However, solid-state batteries still face some challenges, on one hand, in the field of flexible wearable electronics, complex deformations such as impact, bending, stretching, folding and twisting are often encountered, which results in damage inside the electrolyte material, and on the other hand, the electrolyte material is easily structurally damaged during cycling. These structural damages and damages are often difficult to detect and repair, which reduces the service life of the battery and even causes safety problems such as battery fire. Therefore, how to make a solid-state battery have the capacity of bearing volume change and complex deformation, even repairing damage, while improving the electrochemical performance of the solid-state battery is a problem to be solved at present.

Disclosure of Invention

In view of the above, the present invention is directed to a self-repairing solid electrolyte, and a preparation method and an application thereof, so as to solve the problems of poor stability and low applicability of energy storage and release of a solid-state battery in an extreme environment.

In order to achieve the purpose, the technical scheme of the invention is realized as follows: a preparation method of a self-repairing solid electrolyte comprises the following specific steps:

s1, mixing the dissociated lithium salt compound with a solvent, and carrying out ultrasonic treatment to obtain a dissociation solution;

s2, adding a self-repairing polymer, a cross-linking agent and lithium salt into the dissociation liquid, uniformly mixing, and heating to react to obtain a self-repairing precursor solution;

s3, placing the self-repairing precursor solution on a polytetrafluoroethylene plate to prepare a membrane, and drying in vacuum to obtain the self-repairing solid electrolyte.

Optionally, in S1, the dissociated lithium salt compound includes at least one of polyethylene glycol, polyvinylidene fluoride-hexafluoropropylene, polyethylene oxide, polypropylene carbonate, poly (ethylene glycol) methyl ether methacrylate, polyethylene carbonate, and polytrimethylene carbonate;

the solvent includes at least one of N-N dimethylformamide, tetrahydrofuran, N-methylpyrrolidone, N-N dimethylformamide, acetonitrile, acetone, and dimethyl sulfoxide.

Optionally, in S2, the self-healing polymer is DL- α -lipoic acid;

the lithium salt comprises at least one of lithium trifluoromethanesulfonylimide, lithium hexafluorophosphate, lithium perchlorate, lithium tetrafluoroborate, lithium nitrate, lithium difluorophosphate, lithium dioxalate borate, lithium hexafluoroarsenate, lithium difluorosulfonylimide and lithium difluorooxalateborate;

the crosslinking agent comprises a covalent crosslinking agent and a non-covalent crosslinking agent, and the covalent crosslinking agent comprises at least one of 1, 3-diisopropenyl benzene, ionic liquid containing mono-olefin and ionic liquid containing diene; the non-covalent crosslinking agent comprises a ferric salt.

Optionally, in the self-repairing solid electrolyte, the mass fraction of the dissociated lithium salt compound is 10 to 70%, the mass fraction of the self-repairing polymer is 40 to 80%, the mass fraction of the lithium salt is 5 to 50%, the mass fraction of the covalent crosslinking agent is 4.99 to 20%, and the mass fraction of the non-covalent crosslinking agent is 0.01 to 1%.

Optionally, in S2, the temperature-increasing reaction conditions include a reaction temperature of 50 to 90 ℃ and a reaction time of 40min to 12 h.

Optionally, in S2, the self-repair polymer, the cross-linking agent, and the lithium salt are added to the dissociation solution, mixed uniformly, and heated to react to obtain the self-repair precursor solution, which specifically includes the steps of:

s21, dissolving the lithium salt in the ionic liquid, and uniformly stirring to obtain a lithium salt mixed solution;

s22, adding the self-repairing polymer, the lithium salt mixed solution and the cross-linking agent into the dissociation solution, and heating to react to obtain a self-repairing precursor solution.

Optionally, the ionic liquid comprises at least one of 1-allyl-3-vinylimidazole bistrifluoromethylsulfonyl imide salt, 1-allyl-3-vinylimidazole tetrafluoroborate, 1-allyl-3-vinylimidazole hexafluorophosphate, 1-vinyl-3-butylimidazole bistrifluoromethylsulfonyl imide salt, 1-vinyl-3-butylimidazole tetrafluoroborate, 1-vinyl-3-butylimidazole hexafluorophosphate, 1-allyl-3-methylimidazole bistrifluoromethylsulfonyl imide salt, 1-allyl-3-methylimidazole tetrafluoroborate, and 1-allyl-3-methylimidazole hexafluorophosphate.

Compared with the prior art, the preparation method of the self-repairing solid electrolyte provided by the invention has the following advantages:

the self-repairing solid electrolyte is prepared by mixing a self-repairing polymer with a dissociated lithium salt compound and a lithium salt and performing simple heating copolymerization, and has three dynamic chemical bonds: the solid electrolyte has the advantages of tensile property, room-temperature self-repairing property and repeatable processing property due to the synergistic effect of the three dynamic chemical bonds. In addition, the preparation process of the self-repairing solid electrolyte is simple, the cost is low, the self-repairing solid electrolyte is easy to obtain, the process is green and environment-friendly, and the self-repairing solid electrolyte has important industrial popularization significance.

The invention also aims to provide a self-repairing solid electrolyte to solve the problems of poor stability and low applicability of energy storage and release of a solid battery in an extreme environment.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

the self-repairing solid electrolyte comprises a self-repairing polymer, a dissociated lithium salt compound, a lithium salt and a cross-linking agent, wherein the dissociated lithium salt compound and the lithium salt are uniformly dispersed in the self-repairing solid electrolyte.

Optionally, the self-healing polymer contains coordination bonds, reversible covalent bonds, and hydrogen bonds.

The third purpose of the invention is to provide the application of the self-repairing solid electrolyte, so as to solve the problems of poor stability and low applicability of energy storage and release of the solid battery in an extreme environment.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

the self-repairing solid electrolyte is applied to the field of solid lithium batteries.

The self-repairing solid electrolyte and the use of the self-repairing solid electrolyte have the same advantages as the preparation method of the self-repairing solid electrolyte in comparison with the prior art, and are not repeated herein.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, a brief description will be given below to the drawings required for the description of the embodiments or the prior art, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.

FIG. 1 is an optical picture of the self-healing of a self-healing solid electrolyte in example 1 of the present invention;

FIG. 2 is a schematic view of a field emission scanning electron microscope of the self-repairing solid electrolyte in example 2 of the present invention;

FIG. 3 is a schematic view of a field emission scanning electron microscope of the self-repairing solid electrolyte in example 2 of the present invention;

FIG. 4 is a stress-strain curve diagram of the self-healing solid electrolyte in example 1 of the present invention after healing;

FIG. 5 is a lithium symmetric battery cycling curve for a self-healing solid electrolyte of example 1 in accordance with the present invention;

fig. 6 is a schematic flow chart of a method for preparing a self-repairing solid electrolyte according to an embodiment of the present invention.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

The principles and features of this invention are described below in conjunction with the following drawings, which are set forth by way of illustration only and are not intended to limit the scope of the invention.

Self-repairing means that the material can automatically repair invisible cracks caused by the outside (or under the condition of applying external stimulation), so that the cracks are basically healed, and the aim of basically maintaining the performance is fulfilled. The solid electrolyte with self-repairing capability can ensure good electrode-electrolyte interface contact and a continuous lithium ion transmission path of the solid lithium battery in the repeated charge and discharge process, simultaneously prevent the side reaction of the metal lithium and the solid electrolyte interface, and relieve the interface compatibility problems of stress generated by the volume expansion of an electrode material and the like. In recent years, scientists design and prepare solid electrolytes with self-repairing capability and capable of obviously improving service life and safety by using self-repairing materials, however, the solid electrolytes have the problems of low room temperature conductivity and poor mechanical strength; some of the electrolyte is extremely sensitive to water oxygen conditions, so that the application of the solid electrolyte in the field of water-based batteries is limited; and the cycle performance is poor, and the introduction of multiple hydrogen bonds influences the stability of the electrochemical window of the polymer electrolyte.

In order to solve the above problems, with reference to fig. 1 and 6, an embodiment of the present invention provides a method for preparing a self-repairing solid electrolyte, which includes the following specific steps:

s1, mixing the dissociated lithium salt compound with a solvent, and carrying out ultrasonic treatment to obtain a dissociation solution;

s2, adding the self-repairing polymer, the cross-linking agent and the lithium salt into the dissociation liquid, uniformly mixing, and heating to react to obtain a self-repairing precursor solution;

and S3, placing the self-repairing precursor solution on a polytetrafluoroethylene plate to prepare a membrane, and drying in vacuum to obtain the self-repairing solid electrolyte.

Specifically, in step S1, the dissociated lithium salt compound includes at least one of polyethylene glycol, polyvinylidene fluoride-hexafluoropropylene, polyethylene oxide, polypropylene carbonate, poly (ethylene glycol) methyl ether methacrylate, polyethylene carbonate, and polytrimethylene carbonate; the solvent includes at least one of N-N dimethylformamide, tetrahydrofuran, N-methylpyrrolidone, N-N dimethylformamide, acetonitrile, acetone, and dimethyl sulfoxide.

In step S2, the self-repairing polymer is DL-alpha-lipoic acid; the lithium salt includes at least one of lithium trifluoromethanesulfonylimide, lithium hexafluorophosphate, lithium perchlorate, lithium tetrafluoroborate, lithium nitrate, lithium difluorophosphate, lithium dioxalate borate, lithium hexafluoroarsenate, lithium difluorosulfonylimide, and lithium difluorooxalateborate.

The crosslinking agent comprises a covalent crosslinking agent and a non-covalent crosslinking agent, wherein the covalent crosslinking agent is a diene-containing compound and comprises at least one of 1, 3-diisopropenyl benzene, monoolefin-containing ionic liquid and diene-containing ionic liquid; the non-covalent cross-linking agent is a ferric salt, such as anhydrous ferric chloride, which participates in coordination and complexation.

In the self-repairing solid electrolyte, the mass fraction of the dissociated lithium salt compound is 10-70%, the mass fraction of the self-repairing polymer is 40-80%, the mass fraction of the lithium salt is 5-50%, the mass fraction of the covalent cross-linking agent is 4.99-20%, and the mass fraction of the non-covalent cross-linking agent is 0.01-1%.

In step S2, after the self-repairing polymer, the cross-linking agent, and the lithium salt are added to the dissociation liquid, the temperature rise reaction conditions include a reaction temperature of 50 to 90 ℃ and a reaction time of 40min to 12 h.

In order to improve the reaction degree and enable the self-repairing solid electrolyte to have better self-repairing capability, preferably, in S2, the self-repairing polymer, the cross-linking agent and the lithium salt are added into the dissociation liquid, mixed uniformly, and subjected to a temperature rise reaction to obtain a self-repairing precursor solution, specifically comprising the following steps:

s21, dissolving lithium salt in the ionic liquid, and uniformly stirring to obtain a lithium salt mixed solution;

and S22, adding the self-repairing polymer, the lithium salt mixed solution and the cross-linking agent into the dissociation solution, and heating to react to obtain the self-repairing precursor solution.

Wherein the ionic liquid comprises at least one of 1-allyl-3-vinylimidazole bistrifluoromethylsulfonyl imide salt, 1-allyl-3-vinylimidazole tetrafluoroborate, 1-allyl-3-vinylimidazole hexafluorophosphate, 1-vinyl-3-butylimidazole bistrifluoromethylsulfonyl imide salt, 1-vinyl-3-butylimidazole tetrafluoroborate, 1-vinyl-3-butylimidazole hexafluorophosphate, 1-allyl-3-methylimidazole bistrifluoromethylsulfonyl imide salt, 1-allyl-3-methylimidazole tetrafluoroborate, and 1-allyl-3-methylimidazole hexafluorophosphate.

The lithium salt is dissolved in the ionic liquid to obtain a lithium salt mixed solution, and then the lithium salt mixed solution, the self-repairing polymer and the cross-linking agent are added into the dissociation liquid, so that the electrolyte can keep higher conductivity, and the safety of the battery is improved.

The preparation method of the self-repairing solid electrolyte provided by the embodiment of the invention utilizes the self-repairing polymer to mix with the dissociated lithium salt compound and the lithium salt, and obtains the self-repairing solid electrolyte through simple heating copolymerization, and the self-repairing solid electrolyte realizes self-repairing through three dynamic bonds, namely the coordination of carboxyl and ferric ion in the chain segment structure of the self-repairing polymer, the disulfide bond function in the structure of the self-repairing polymer, and the hydrogen bond function of the chain segment carboxyl and the dissociated lithium salt compound, so that the self-repairing solid electrolyte has three dynamic chemical bonds: the solid electrolyte has the advantages of tensile property, room-temperature self-repairing property and repeatable processing property due to the synergistic effect of the three dynamic chemical bonds. In addition, the preparation process of the self-repairing solid electrolyte is simple, the cost is low, the self-repairing solid electrolyte is easy to obtain, the process is green and environment-friendly, and the self-repairing solid electrolyte has important industrial popularization significance.

The embodiment of the invention also provides a self-repairing solid electrolyte which is prepared by adopting the preparation method of the self-repairing solid electrolyte, the self-repairing solid electrolyte comprises a self-repairing polymer, a dissociated lithium salt compound, a lithium salt and a cross-linking agent, the dissociated lithium salt compound and the lithium salt are uniformly dispersed in the self-repairing solid electrolyte, and the self-repairing polymer contains a coordination bond, a reversible covalent bond and a hydrogen bond.

Therefore, the solid electrolyte has the advantages of tensile property, room-temperature self-repairing property and repeatable processing property due to the coordination bond, the reversible covalent bond and the hydrogen bond and the synergistic effect of the three dynamic chemical bonds, and meanwhile, the self-repairing solid electrolyte membrane has the advantages of safety, non-flammability, high ionic conductivity and the like, is expected to replace flammable commercial electrolyte, and is widely applied to the latest solid battery field.

The invention also provides the application of the self-repairing solid electrolyte, the self-repairing solid electrolyte can be applied to the field of solid lithium batteries, the self-repairing composite solid electrolyte is bendable in dry basis, flexible and self-repairing, can inhibit the growth of lithium dendrites, solves the problems of poor stability and low applicability of energy storage and release of the solid batteries in extreme environments, and has a self-repairing function, so that the service life of the lithium batteries can be effectively prolonged, and the self-repairing solid electrolyte has a wide application prospect.

The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. The following examples are examples of experimental procedures not specified under specific conditions, generally according to the conditions recommended by the manufacturer. Unless otherwise indicated, percentages and parts are by mass.

Example 1

The embodiment provides a preparation method of a self-repairing solid electrolyte, which comprises the following specific steps:

1) preparation of dissociation liquid

2g of polyvinylidene fluoride and N-N dimethylformamide (molecular sieve treatment) are uniformly mixed to obtain a dissociation liquid.

2) Preparation of self-repairing precursor solution

Adding 4g of DL-alpha-lipoic acid, 0.4g of 1, 3-diisopropenylbenzene and 0.2g of polyethylene glycol diacrylate into the dissociation solution, reacting at 75 ℃ and stirring for 10 minutes, then adding 10mg of anhydrous ferric chloride, and continuing to heat for a period of time until the anhydrous ferric chloride is completely dissolved in the solution; and cooling to room temperature, adding 0.2g of lithium perchlorate, and stirring for 12 hours to obtain the self-repairing precursor solution.

3) Preparation of self-repairing solid electrolyte

And (3) placing the self-repairing precursor solution in a polytetrafluoroethylene mold, uniformly mixing, and placing the mold in a 70 ℃ oven for drying for 24h to obtain the self-repairing solid electrolyte.

Example 2

The difference between the present embodiment and embodiment 1 is that the present embodiment provides a method for preparing a self-repairing solid electrolyte, which includes the following specific steps:

1) preparation of dissociation liquid

3g of polyvinylidene fluoride-hexafluoropropylene and acetonitrile are uniformly mixed to obtain dissociation liquid.

2) Preparation of self-repairing precursor solution

188mg of lithium bistrifluoromethylsulfonyl imide was dissolved in 812mg of 1-allyl-3-vinylimidazole bistrifluoromethylsulfonyl imide salt, and the mixture was stirred for 2 hours to obtain a lithium salt mixture.

Adding 6g of DL-alpha-lipoic acid and 1g of lithium salt mixed solution into the dissociation solution, uniformly stirring, heating at 75 ℃ for 10 minutes, injecting 1.2g of 1, 3-diisopropenylbenzene and 15mg of anhydrous ferric chloride by using an injector, and continuously heating at 75 ℃ for 30 minutes to obtain the self-repairing precursor solution.

3) Preparation of self-repairing solid electrolyte

And (3) placing the self-repairing precursor solution in a polytetrafluoroethylene mold, uniformly mixing, and placing the mold in a 70 ℃ oven for drying for 24h to obtain the self-repairing solid electrolyte.

In order to test the performance of the self-repairing solid electrolyte prepared in the embodiments 1 and 2 of the present invention, the self-repairing solid electrolyte is assembled into a lithium symmetric battery, and a performance test is performed, wherein the specific test conditions are as follows:

the lithium symmetrical battery is assembled by a sandwich structure of a self-repairing solid electrolyte membrane of a lithium clamp, and the current density is 0.05mA/cm²The charging and discharging time is 1h respectively, and the testing temperature is 27 ℃.

Fig. 1 is a picture of self-repairing of the self-repairing solid electrolyte prepared in example 1 after being cut open at room temperature and in contact with the solid electrolyte for 10 minutes, and it can be seen from fig. 1 that the self-repairing solid electrolyte prepared in example 1 can complete self-repairing within about 2.5 hours, and the solid electrolyte after the self-repairing is completed has excellent flexibility and ductility.

Fig. 2 is a schematic view of a field emission scanning electron microscope of the self-repairing solid electrolyte prepared in example 1, and it can be seen from fig. 2 that the surface of the self-repairing polymer film prepared in example 1 is relatively smooth, and the polymer is uniformly dispersed.

Fig. 3 is a schematic view of a field emission scanning electron microscope of the self-repairing solid electrolyte prepared in example 2, and it can be seen from fig. 3 that the ionic liquid can be well dispersed in the self-repairing solid electrolyte prepared in example 2.

Fig. 4 is a mechanical property test chart of the self-repairing solid electrolyte prepared in example 1 after damage is recovered, and it can be seen from fig. 4 that the maximum tensile stress of the self-repairing solid electrolyte can reach 0.24 MPa.

Fig. 5 shows the cycle of the lithium symmetric battery assembled with the self-repairing solid electrolyte prepared in example 1, and it can be seen from fig. 5 that the self-repairing solid electrolyte prepared in example 1 shows a more stable polarization voltage after 500h of cycle.

The test shows that the self-repairing solid electrolyte prepared by the embodiment of the invention has higher room-temperature ionic conductivity, excellent stretchability and bendability, is not flammable under open fire conditions, has good safety, and has stable self-repairing performance and excellent electrochemical performance.

Example 3

This example differs from example 1 in that:

in the step 2), 8g of DL-alpha-lipoic acid, 0.24g of 1, 3-diisopropenylbenzene and 0.25g of polyethylene glycol diacrylate are added into the solution, and after the mixture reacts and is stirred for 10 minutes at 75 ℃, 1mg of anhydrous ferric chloride is added, and the heating is continued for a period of time until the anhydrous ferric chloride is completely dissolved in the solution; and cooling to room temperature, adding 0.5g of lithium perchlorate, and stirring for 12 hours to obtain the self-repairing precursor solution. That is, in the self-repairing solid electrolyte, the mass fraction of the dissociated lithium salt compound is 10%, the mass fraction of the self-repairing polymer is 80%, the mass fraction of the lithium salt is 5%, the mass fraction of the covalent crosslinking agent is 4.99%, and the mass fraction of the non-covalent crosslinking agent is 0.01%.

Other parameters were the same as in example 1.

Example 4

This example differs from example 2 in that:

in the step 2), 406mg of lithium bistrifluoromethylsulfonyl imide is dissolved in 812mg of 1-allyl-3-vinylimidazole bistrifluoromethylsulfonyl imide salt, and the mixture is stirred for 2 hours to obtain a lithium salt mixed solution;

adding 4g of DL-alpha-lipoic acid and 1.21g of lithium salt mixed solution into the dissociation solution, uniformly stirring, heating at 75 ℃ for 10 minutes, injecting 2.1g of 1, 3-diisopropenylbenzene and 0.1g of anhydrous ferric chloride by using an injector, and continuously heating at 75 ℃ for 30 minutes to obtain the self-repairing precursor solution. That is, in the self-repairing solid electrolyte, the mass fraction of the dissociated lithium salt compound is 70%, the mass fraction of the self-repairing polymer is 40%, the mass fraction of the lithium salt is 50%, the mass fraction of the covalent crosslinking agent is 21%, and the mass fraction of the non-covalent crosslinking agent is 1%.

Other parameters were the same as in example 1.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.