CN108933284B

CN108933284B - Flexible all-solid-state lithium ion secondary battery and preparation method thereof

Info

Publication number: CN108933284B
Application number: CN201710385193.0A
Authority: CN
Inventors: 李林; 刘凤泉; 周建军; 方芳
Original assignee: Beijing Normal University
Current assignee: Beijing Normal University
Priority date: 2017-05-26
Filing date: 2017-05-26
Publication date: 2020-11-06
Anticipated expiration: 2037-05-26
Also published as: CN108933284A

Abstract

The invention discloses a flexible all-solid-state lithium ion secondary battery and a preparation method thereof, the flexible all-solid-state lithium ion secondary battery is characterized in that a positive electrode and a negative electrode or an optional diaphragm for the lithium ion secondary battery are arranged in a gellable system without forming solid electrolyte by infiltration or by adopting a coating mode, so that the surfaces and the inside of the positive electrode and the negative electrode are infiltrated by the gellable system, and enters the gaps inside the positive and negative electrodes, after the gel system is solidified to form a solid electrolyte, the solid electrolyte can be formed on the surfaces of the positive and negative pole pieces and in the lithium ion secondary battery prepared by the method in situ, and a conductive network can be formed in the whole battery, so that the internal resistance of the lithium ion secondary battery can be greatly reduced, thereby improving the conductivity and the rate performance and solving the potential safety hazard brought by the liquid electrolyte.

Description

Flexible all-solid-state lithium ion secondary battery and preparation method thereof

Technical Field

The invention belongs to the technical field of lithium ion batteries, and particularly relates to a flexible all-solid-state lithium ion secondary battery and a preparation method thereof.

Background

Technological advances have led to the rapid development of lithium ion secondary batteries for providing power to consumer electronics, however, lithium ion secondary batteries also present non-trivial safety hazards during their use, such as: leakage, burning, explosion, etc. of the electrolyte. Since batteries must be safe on the premise of satisfying normal production and life of human beings, the safety of lithium ion secondary batteries is also a hot topic to be searched by researchers. At present, the main solution for solving the electrolyte leakage of the lithium ion secondary battery is to adopt a solid electrolyte, which has the incomparable advantages of a liquid electrolyte, and is likely to become a technical approach for solving the safety problem of the lithium ion secondary battery. Moreover, compared with a liquid lithium ion secondary battery, the all-solid-state lithium ion secondary battery has great advantages in the aspects of widening the working temperature range, improving the energy density of the battery, prolonging the service life and the like.

Solid electrolytes can be classified into polymer composite lithium ion electrolytes and all-solid-state thin film lithium ion electrolytes according to their components. The polymer composite lithium ion electrolyte mainly adopts a coordination structure formed by a high molecular polymer and a lithium salt so as to realize the conduction of lithium ions, and a certain amount of silicon dioxide (SiO) is often added for improving the conductivity of the lithium ions₂) Alumina (Al)₂O₃) And inorganic fillers such as zeolite.

The currently reported method for using a solid electrolyte in a lithium ion secondary battery generally places a solid electrolyte membrane between a positive electrode and a negative electrode, and although the preparation method can effectively block the contact between the positive electrode and the negative electrode, the interface resistance between the solid electrolyte and the positive electrode and between the solid electrolyte and the negative electrode cannot be overcome, and the electrolyte is a solid film, so that the inside of an electrode plate cannot be fully contacted with the solid electrolyte, and the prepared lithium ion secondary battery has the defects of poor conductivity, large interface internal resistance, poor rate capability and the like.

Meanwhile, all solid-state lithium ion secondary batteries used at present are rigid, and have the defects of heavy weight, easiness in crushing, poor strain property, poor restorability, poor electrochemical performance of the batteries, poor cycle performance, short endurance time and the like.

Disclosure of Invention

In order to solve the above problems in the prior art, an object of the present invention is to provide a flexible all-solid-state lithium ion secondary battery and a method for manufacturing the same.

The inventor researches and discovers that in the currently used solid-state lithium ion secondary battery, the conventional liquid electrolyte is often replaced by the solid-state electrolyte, even the diaphragm is replaced, however, in the solid-state lithium ion secondary battery prepared in the way, because the solid-state electrolyte can only contact with the surface of the electrode, a conductive network can only be formed on the surface of the electrode, but a conductive network cannot be formed in the electrode, and in addition, huge interface resistance can also be formed in the part which is not in contact with the electrode, active materials in the positive electrode and the negative electrode cannot be fully utilized, so that the electrochemical performance, the cycling stability and the cycle life of the lithium ion secondary battery are severely limited. The invention adopts a gellable system as the solid electrolyte for the lithium ion secondary battery, before the solid electrolyte is formed, the anode and the cathode for the lithium ion secondary battery can be placed in the gellable system without the solid electrolyte through infiltration or in a coating mode, so that the surfaces and the inside of the anode and the cathode are infiltrated by the gellable system and enter the gaps inside the anode and the cathode, and after the gellable system is solidified, the gellable system can form the solid electrolyte on the surfaces of the anode and the cathode and in the inside of the anode and the cathode in situ. The lithium ion secondary battery prepared by the method forms a conductive network in the whole battery, so that the active substances can fully play a role, the internal resistance of the lithium ion secondary battery is greatly reduced, the conductivity and the rate capability are improved, the potential safety hazard caused by liquid electrolyte can be solved, and the lithium ion secondary battery has good strainability and recoverability and is portable and easy to carry. In addition, by controlling the types and the contents of the components in the gellable system for preparing the solid electrolyte, the solid electrolyte with adjustable strength, adjustable formation time (namely, the state of the solid electrolyte which can be freely flowed is converted into the state of the non-flowable solid electrolyte), adjustable transition temperature (namely, the lowest temperature when the state of the electrolyte which can be non-flowable is converted into the state of the liquid which can be freely flowed), namely, the solid electrolytes with different strengths can be prepared according to specific requirements so as to meet different requirements. The solid electrolyte also has good reversibility, and when the temperature reaches the transition temperature of the solid electrolyte, the fluidity of the solid electrolyte is enhanced, and when the temperature drops below the transition temperature, the solid electrolyte is reformed, and the property of the solid electrolyte is not influenced. The present invention has been completed based on the above-described concept.

The purpose of the invention is realized by the following technical scheme:

a method for preparing a flexible all-solid-state lithium ion secondary battery, comprising the steps of:

1) preparing a gellable system;

2) pressing a negative electrode current collector and a negative electrode material into a negative electrode, and then placing the negative electrode in the gellable system in the step 1) for infiltration; or coating the gellable system obtained in the step 1) on the surface of a negative electrode formed by pressing a negative electrode current collector and a negative electrode material;

3) pressing a positive electrode current collector and a positive electrode material into a positive electrode, and then placing the positive electrode in the gellable system in the step 1) for infiltration; or coating the gellable system obtained in the step 1) on the surface of the positive electrode pressed by the positive electrode current collector and the positive electrode material;

4) pressing the soaked or coated negative electrode, optional diaphragm and positive electrode into a whole in a battery pressing mould to form a pre-liquid injection all-solid-state battery, namely the flexible all-solid-state lithium ion secondary battery;

wherein the gellable system comprises the following components: lithium salt and ether compounds, wherein the ether compounds are selected from one of cyclic ether compounds or linear ether compounds; the mass percentage of the gellable polymer and/or the gellable prepolymer in the system is 1wt% or less.

According to the present invention, the method for manufacturing the flexible all-solid-state lithium ion secondary battery further comprises the steps of:

5) injecting the gellable system in the step 1) into the all-solid-state battery before injection in the step 4);

6) and (3) carrying out secondary pressing on the all-solid-state battery injected with the gel system, taking out the all-solid-state battery from a battery pressing die, and standing to prepare the flexible all-solid-state lithium ion secondary battery.

According to the invention, the gellable system may also comprise at least one of inorganic nanoparticles, other solvents and/or electrolytes, additives such as polyesters or blends thereof.

According to the invention, in step 1), the sum of the percentages by weight of the components in the gellable system is 100 wt.%.

According to the invention, the mass percentage of the lithium salt is more than or equal to 20wt% and less than or equal to 75 wt%; the mass percentage of the ether compound is more than or equal to 25 wt% and less than or equal to 80 wt%; the mass percentage of the other solvents and/or the electrolyte is more than or equal to 0wt% and less than or equal to 75 wt%; the mass percentage of the inorganic nano particles is more than or equal to 0wt% and less than or equal to 30 wt%; the mass percentage of the additive is more than or equal to 0wt% and less than or equal to 60 wt%.

Preferably, the mass percentage content of the lithium salt is more than or equal to 20wt% and less than or equal to 30 wt%; the mass percentage of the ether compound is more than or equal to 70wt% and less than or equal to 80 wt%; the mass percentage of the other solvents and/or the electrolyte is more than or equal to 0wt% and less than or equal to 60 wt%; the mass percentage of the inorganic nano particles is more than or equal to 0wt% and less than or equal to 20 wt%; the mass percentage of the additive is more than or equal to 0wt% and less than or equal to 20 wt%.

According to the invention, in step 1), the process for preparing the gelable system comprises in particular the following steps:

mixing an ether compound, a lithium salt, other optional solvents and/or electrolyte, inorganic nanoparticles and additives, and stirring to obtain a mixed solution, namely the gellable system.

Preferably, the process for the preparation of said gelable system comprises in particular the following steps:

adding an ether compound into a lithium salt, stirring to obtain an ether compound solution of the lithium salt, and optionally adding other solvents and/or electrolytes and/or inorganic nano particles and/or additives into a linear ether compound solution of the lithium salt, namely the gellable system.

According to the invention, the ether compound, the lithium salt, the optional inorganic nanoparticles, the optional other solvent and/or electrolyte and the optional additive are subjected to a preliminary water removal treatment; preferably, the ether compound, the lithium salt, the optional inorganic nanoparticles, the optional other solvent and/or electrolyte and the optional additive are subjected to a preliminary water removal treatment by using a molecular sieve and/or vacuum drying method.

According to the invention, in steps 2) and 3), the pressing of the positive electrode or the negative electrode into a whole is carried out under dry conditions.

According to the invention, in the steps 2) and 3), the coating is selected from at least one of spraying, blade coating, coating roller, coating brush and the like.

In the invention, in the steps 2) and 3), the soaking time and the soaking temperature are not limited; when the soaking temperature is lower than the transition temperature of the solid electrolyte formed by the gellable system, the soaking time is preferably less than the time for the gellable system to form the solid electrolyte; alternatively, when the soaking temperature is higher than the transition temperature of the solid electrolyte formed by the gellable system, it is understood by those skilled in the art that the gellable system cannot form a gel, and thus the soaking time is not limited.

According to the present invention, there is no limitation on the selection of the negative electrode current collector, the negative electrode material, the separator, the positive electrode material, and the positive electrode current collector, and those skilled in the art can understand that the flexible all-solid-state lithium ion secondary battery of the present invention may be applied.

Preferably, the negative electrode current collector is selected from at least one of copper foil, copper alloy, silver foil, stainless steel sheet, and carbon material.

Preferably, the negative electrode material is selected from at least one of metal-based negative electrode materials (such as metallic lithium, lithium alloy and the like), inorganic non-metal-based negative electrode materials (such as carbon materials, silicon materials and other composite materials of different non-metals and the like).

Preferably, the separator is selected from at least one of a solid electrolyte separator prepared from the gellable system of the invention or a polyolefin porous membrane, such as a polyethylene microporous membrane, a polypropylene microporous membrane and a three-layer composite separator.

Preferably, the positive electrode material is selected from lithium cobalt oxide, lithiumNickel oxide, lithium manganese oxide, ternary nickel cobalt manganese oxide, nano-grade positive electrode material (such as nano-crystal spinel LiMn)₂O₄Barium-magnesium-manganese ore type MnO₂Nano-fiber and polypyrrole coated spinel type LiMn₂O₄Nanotube, polypyrrole/V₂O₅Nano composite material, etc.), blended electrodes, vanadium oxide, layered compounds (such as ferric oxychloride modified by aniline, etc.).

Preferably, the positive electrode current collector is selected from at least one of aluminum foil and aluminum alloy.

According to the invention, in step 6), the time of standing is the formation time of the gellable system used to transform into a solid electrolyte, and the temperature of standing is room temperature.

The invention also provides a flexible all-solid-state lithium ion secondary battery, which is prepared by adopting the method.

According to the present invention, the lithium ion secondary battery includes a lithium ion battery, a lithium sulfur battery, a lithium air battery, and the like.

The invention has the beneficial effects that:

the invention provides a flexible all-solid-state lithium ion secondary battery and a preparation method thereof, the flexible all-solid-state lithium ion secondary battery is characterized in that the positive and negative electrodes or optional diaphragms for the lithium ion secondary battery are arranged in a gellable system without solid electrolyte by soaking or adopting a coating mode, so that the surfaces and the inside of the positive and negative electrodes are soaked by the gellable system, and enters the gaps inside the positive and negative electrodes, after the gel system is solidified to form a solid electrolyte, the solid electrolyte can be formed on the surfaces of the positive and negative pole pieces and in the lithium ion secondary battery prepared by the method in situ, and a conductive network can be formed in the whole battery, so that the internal resistance of the lithium ion secondary battery can be greatly reduced, thereby improving the conductivity and the rate performance and solving the potential safety hazard brought by the liquid electrolyte.

Drawings

Fig. 1 is a graph of rate performance of a battery obtained in the formulation formula of example 2.

Fig. 2 is a graph of rate performance of the battery obtained in the charge formula of example 4.

Fig. 3 is a graph of rate performance of a battery obtained in the charge formula of example 6.

Detailed Description

[ lithium salt ]

The gellable system of the present invention includes a lithium salt, which may be selected from one or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium hexafluoroarsenate, lithium perchlorate, lithium trifluoromethanesulfonate, lithium perfluorobutanesulfonate, lithium bistrifluoromethanesulfonylimide, lithium aluminate, lithium chloroaluminate, lithium fluorosulfonylimide, lithium chloride and lithium iodide; preferably, the lithium salt is selected from one or two of lithium hexafluorophosphate, lithium perchlorate and the like.

[ Ether Compound ]

The gellable system of the present invention includes an ether compound, and the ether compound is selected from one of a cyclic ether compound and a linear ether compound.

[ Cyclic ether Compound ]

The ether compound of the present invention may be selected from cyclic ether compounds containing one oxygen, two oxygen, three oxygen or more oxygen.

In the present invention, the cyclic ether compound is selected from C containing at least 1 oxygen atom₂～C₂₀Cycloalkanes (i.e. having 2 to 20 carbon atoms in the ring structure) or C containing at least 1 oxygen atom₃～C₂₀Cyclic olefins (i.e., cyclic structures having 3 to 20 carbon atoms) which contain at least one carbon-carbon double bond.

In the present invention, the cycloalkane or cycloalkene is a monocyclic ring, a fused ring (e.g., bicyclic ring), a spiro ring or a bridged ring; when the cycloalkane or cycloalkene is a spiro ring or bridged ring and contains two or more oxygen atoms, the oxygen atoms may be in one ring or in a plurality of rings.

In the present invention, the cyclic ether compound is selected from C containing at least 1 oxygen atom₂～C₂₀Preferably selected from C containing at least 1 oxygen atom₃～C₂₀Such as one of the following first compounds:

in the present invention, the cyclic ether compound is selected from C containing at least 1 oxygen atom₄～C₂₀The fused cycloalkane of (a) is, for example, one of the following second classes of compounds:

in the present invention, the cyclic ether compound is selected from C containing at least 1 oxygen atom₄～C₂₀For example, one of the following compounds of the third class:

in the present invention, the cyclic ether compound is selected from C containing at least 1 oxygen atom₄～C₂₀The spirocycloalkane of (a) is, for example, one of the following fourth classes of compounds:

in the present invention, the compound in which at least one of the C — C bonds in the ring structure in the above-mentioned four groups is replaced with C ═ C and which is stably present is the above-mentioned C having at least 1 oxygen atom₃～C₂₀Cyclic olefins, which are one of the preferred cyclic ether compounds of the present invention.

In the present invention, when the cycloalkane or cycloalkene is monocyclic or fused, carbon atoms on the ring may be substituted with 1 or more R1 groups; where the cycloalkane or cycloalkene is a bridged ring, its unbridged ring carbon atoms may be substituted with 1 or more R1 groups; when the cycloalkane or cycloalkene is a spiro ring, the carbon atoms on the ring may be substituted with 1 or more R1 groups; the R1 group is selected from one of the following groups: alkyl, alkenyl, alkynyl, alkoxy, alkylthio, haloalkyl, cycloalkyl, cycloalkyloxy, cycloalkylthio, heterocyclyl, heterocyclyloxy, heterocyclylthio, aryl, aryloxy, heteroaryl, heteroaryloxy, hydroxy, mercapto, nitro, carboxy, amino, ester, halogen, acyl, aldehyde.

In the present invention, the cyclic ether compound containing one oxygen is selected from substituted or unsubstituted oxetane, substituted or unsubstituted tetrahydrofuran, and substituted or unsubstituted tetrahydropyran; the number of the substituents may be one or more; the substituent is the R1 group described above.

In the present invention, the cyclic ether compound containing one oxygen is selected from the group consisting of 3, 3-dichloromethyloxetane, 2-chloromethyloxetane, 2-chloromethylpropylene oxide, 1, 4-epoxycyclohexane, 1, 3-epoxycyclohexane, tetrahydrofuran, 2-methyltetrahydrofuran, 3-methyltetrahydrofuran, tetrahydropyran, 2-methyltetrahydropyran, oxepane, oxepin, oxprenane and oxprenane.

In the invention, the cyclic ether compound containing two oxygens is selected from substituted or unsubstituted 1, 3-Dioxolane (DOL) and substituted or unsubstituted 1, 4-dioxane; the number of the substituents may be one or more; the substituent is the R1 group described above.

In the invention, the cyclic ether compound containing three oxygens is selected from substituted or unsubstituted trioxymethylene; the number of the substituents may be one or more; the substituent is the R1 group described above.

In the present invention, the ether compound containing more oxygen is selected from the group consisting of substituted or unsubstituted 18-crown-6, substituted or unsubstituted 12-crown-4, and substituted or unsubstituted 24-crown-8; the number of the substituents may be one or more; the substituent is the R1 group described above.

[ straight-chain ether compound ]

In the invention, the general formula of the linear ether compound is shown as formula (1):

R₁—O—(R₂—O)_n—R₃formula (1)

Wherein n is an integer greater than 0;

R₂selected from straight or branched C₁-C₆Alkylene, straight or branched C₂-C₆Alkenylene of (a); the R is₂H on the carbon atom(s) may be substituted with at least one of the following groups: alkenyl, alkynyl, alkoxy, alkylthio, cycloalkyl, cycloalkyloxy, cycloalkylthio, heterocyclyl, heterocyclyloxy, heterocyclylthio, aryl, aryloxy, heteroaryl, heteroaryloxy, hydroxy, mercapto, nitro, carboxy, amino, ester, halogen, acyl, aldehyde group;

R₁and R₃The alkyl, the cycloalkyl, the heterocyclic radical, the alkenyl and the alkynyl are selected from one or more of hydrogen atoms, alkyl, cycloalkyl, heterocyclic radical, alkenyl and alkynyl; the R is₁And R₃H on the carbon atom of (a) may be substituted with at least one of the following groups: alkenyl, alkynyl, alkoxy, alkylthio, cycloalkyl, cycloalkyloxy, cycloalkylthio, heterocyclyl, heterocyclyloxy, heterocyclylthio, aryl, aryloxy, hydroxy, mercapto, nitro, carboxy, amino, ester, halogen, acyl, aldehyde group.

Preferably, n is an integer between 1 and 6;

R₂selected from straight or branched C₁-C₄Alkylene, straight or branched C₂-C₆Alkenylene of (a);

R₁and R₃Identical or different, independently of one another, from straight-chain or branched C₁-C₆Alkyl group of (1).

More preferably, R₂Selected from methyl, ethyl, propyl, isopropyl, butyl, isobutyl, vinyl;

R₁and R₃Identical or different, independently of one another, from the group consisting of methyl, ethyl, propyl.

Still preferably, the linear ether compound is one or more selected from ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol methyl ethyl ether, 1, 4-butanediol dimethyl ether, 1, 4-butanediol diethyl ether, 1, 4-butanediol methyl ethyl ether, and the like.

In the present invention, the linear ether compound is, for example, one of the following compounds:

[ gellable System ]

In a preferred embodiment of the invention, the gellable system comprises a lithium salt and an ether compound selected from cyclic ether compounds.

In a preferred embodiment of the present invention, the gellable system comprises a lithium salt, an ether compound selected from cyclic ether compounds, and other solvents and/or electrolytes.

In a preferred embodiment of the present invention, the gellable system comprises a lithium salt, an ether compound selected from cyclic ether compounds, and inorganic nanoparticles.

In a preferred embodiment of the present invention, the gellable system comprises a lithium salt, an ether compound selected from cyclic ether compounds, other solvents and/or electrolytes, and inorganic nanoparticles.

In a preferred embodiment of the present invention, the gellable system comprises a lithium salt, an ether compound selected from cyclic ether compounds, and an additive.

In a preferred embodiment of the invention, the gellable system comprises a lithium salt and an ether compound selected from linear ethers.

In a preferred embodiment of the present invention, the gellable system comprises a lithium salt, an ether compound selected from linear ether compounds, and other solvents and/or electrolytes.

In a preferred embodiment of the present invention, the gellable system comprises a lithium salt, an ether compound selected from linear ether compounds, and inorganic nanoparticles.

In a preferred embodiment of the present invention, the gellable system comprises a lithium salt, an ether compound selected from linear ether compounds, other solvents and/or electrolytes, and inorganic nanoparticles.

[ inorganic nanoparticles ]

In the present invention, the inorganic nanoparticles are selected from one or more of silicon dioxide, aluminum oxide, silicon nitride, zinc oxide, titanium dioxide, silicon carbide, silicate, calcium carbonate, barium sulfate, clay, ferroferric oxide, cerium oxide, nanocarbon materials, iron oxide, etc.; preferably, the inorganic nanoparticles are selected from one or more of silica, alumina, titania, zinc oxide.

[ other solvents and/or electrolytes ]

In the present invention, the gellable system further comprises other solvents and/or electrolytes, and the other solvents and/or electrolytes comprise at least one of an electrolyte for a lithium sulfur battery, a solvent for an electrolyte for a lithium sulfur battery, an electrolyte for a lithium ion battery, and a solvent for an electrolyte for a lithium ion battery.

In a preferred embodiment of the present invention, the electrolyte for a lithium ion battery is selected from an ester mixture containing a lithium salt for a lithium ion battery, for example, lithium hexafluorophosphate (LiPF) containing 1M₆) Wherein the volume ratio of the Ethylene Carbonate (EC) to the dimethyl carbonate (DMC) is 1: 1.

In a preferred embodiment of the present invention, the solvent for the electrolyte of a lithium ion battery is at least one selected from the group consisting of a cyclic nonaqueous organic solvent for the electrolyte of a lithium ion battery and a chain-like nonaqueous organic solvent for the electrolyte of a lithium ion battery.

In a preferred embodiment of the present invention, the cyclic non-aqueous organic solvent of the electrolyte for a lithium ion battery is selected from at least one of Ethylene Carbonate (EC), Propylene Carbonate (PC), fluoroethylene carbonate (FEC), γ -butyrolactone (GBL), Ethylene Sulfite (ES), Propylene Sulfite (PS), Sulfolane (SL), Glycerol Carbonate (GC).

In a preferred embodiment of the present invention, the chain non-aqueous organic solvent of the electrolyte for a lithium ion battery is selected from at least one of diethyl carbonate (DEC), dimethyl carbonate (DMC), Ethyl Methyl Carbonate (EMC), Methyl Propyl Carbonate (MPC), dipropyl carbonate (DPC), Ethyl Propyl Carbonate (EPC), Ethyl Acetate (EA), Propyl Acetate (PA), Ethyl Propionate (EP), Ethyl Butyrate (EB), Methyl Butyrate (MB), dimethyl sulfite (DMS), diethyl sulfite (DES), Ethyl Methyl Sulfite (EMS), dimethyl sulfone (MSM), dimethyl sulfoxide (DMSO).

In a preferred embodiment of the present invention, the electrolyte for a lithium-sulfur battery is selected from an ether-based mixed solution containing a lithium salt, for example: the liquid mixture contains 1M lithium bistrifluoromethanesulfonimide (LiTFSI) and 1, 3-Dioxolane (DOL) and ethylene glycol dimethyl ether (DME), wherein the volume ratio of the 1, 3-Dioxolane (DOL) to the ethylene glycol dimethyl ether (DME) is 1: 1.

In a preferred embodiment of the present invention, the solvent of the electrolyte for a lithium sulfur battery is selected from one or more of 1, 3-dioxolane, 1, 2-dimethoxyethane, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, fluoroethylene carbonate, polyethylene glycol borate, 1 ', 2, 2' -tetrafluoroethyl-2, 2 ', 3, 3' -tetrafluoropropylene ether.

[ additives ]

In the invention, the additive is selected from one or more of polyester or blends thereof; wherein the polyester is obtained by polycondensation of polybasic acid or anhydride and polyalcohol; the polybasic acid is selected from dibasic acid, tribasic acid or higher, and the polyhydric alcohol is selected from dihydric alcohol, trihydric alcohol or higher.

In a preferred embodiment of the invention, the polyacid is selected from one or two or three or more of the following substituted or unsubstituted polyacids: oxalic acid, malonic acid, succinic acid, butenedioic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, azelaic acid, tricarballylic acid; the number of the substituents may be one or more; when the substituent is plural, it may form a ring; the substituent is one or more of alkyl, cycloalkyl, aryl, hydroxyl, amino, ester group, halogen, acyl, aldehyde group, sulfhydryl, alkoxy and the like.

In a preferred embodiment of the invention, the anhydride is selected from one or two or three or more of the following substituted or unsubstituted anhydrides: oxalic anhydride, malonic anhydride, succinic anhydride, maleic anhydride, glutaric anhydride, adipic anhydride, pimelic anhydride, suberic anhydride, sebacic anhydride, azelaic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride; the number of the substituents may be one or more; when the substituent is plural, it may form a ring; the substituent is one or more of alkyl, cycloalkyl, aryl, hydroxyl, amino, ester group, halogen, acyl, aldehyde group, sulfhydryl, alkoxy and the like.

In a preferred embodiment of the present invention, the polyol is selected from one or more of the following substituted or unsubstituted polyols: propylene glycol, butylene glycol, pentylene glycol, hexylene glycol, heptylene glycol, octylene glycol, nonylene glycol, decylene glycol, polyethylene glycol, glycerol; the number of the substituents may be one or more; when the substituent is plural, it may form a ring; the substituent is one or more of alkyl, cycloalkyl, aryl, hydroxyl, amino, ester group, halogen, acyl, aldehyde group, sulfhydryl, alkoxy and the like.

In a preferred embodiment of the present invention, the polyol is selected from polyethylene glycol, or a combination of polyethylene glycol and one or more of the following polyols: propylene glycol, butylene glycol, pentylene glycol, hexylene glycol, heptylene glycol, octylene glycol, nonylene glycol, decylene glycol.

In a preferred embodiment of the present invention, the polymerization degree of the polyethylene glycol is 100-. Wherein the weight ratio of the polyethylene glycol to other polyols is 1 (0-1), preferably 1 (0-0.9), and more preferably 1 (0-0.8).

[ terms and definitions ]

Unless otherwise indicated, the definitions of groups and terms described in the specification and claims of the present application, including definitions thereof as examples, exemplary definitions, preferred definitions, definitions described in tables, definitions of specific compounds in the examples, and the like, may be arbitrarily combined and coupled with each other. Such combinations and definitions of groups and structures of compounds after combination are intended to fall within the scope of the present application.

The term "gel" in the present invention has a meaning well known in the art, and the term "gelation" also has a meaning well known in the art.

The gellable polymer and/or gellable prepolymer in the present invention means a polymer and/or prepolymer which can form a gel or can be gelled under certain conditions.

Without limitation, the gellable polymer and/or gellable prepolymer of the present invention may be selected from one or more of polyethylene oxide (PEO), polyethylene glycol (PEG), polyvinylidene fluoride (PVDF), polyvinyl chloride (PVC), Polystyrene (PS), Polyacrylonitrile (PAN), polyvinyl acetate (PVAC), polyvinylpyrrolidone (PVP), polydivinyl sulfide (PVS), polytrimethylene carbonate (PTMC), polymethyl methacrylate (PMMA), polyethylene glycol dimethacrylate (PEGDM), polypropylene oxide (PPO), Polydimethylsiloxane (PDMSO) or prepolymers thereof, or copolymers thereof, or blends thereof.

Where a range of numerical values is recited in the specification and claims herein, and where the range of numerical values is defined as an "integer," it is understood that the two endpoints of the range are recited and each integer within the range is recited. For example, "an integer of 0 to 10" should be understood to describe each integer of 0, 1,2, 3,4, 5, 6, 7, 8, 9, and 10. When a range of values is defined as "a number," it is understood that the two endpoints of the range, each integer within the range, and each decimal within the range are recited. For example, "a number of 0 to 10" should be understood to not only recite each integer of 0, 1,2, 3,4, 5, 6, 7, 8, 9, and 10, but also to recite at least the sum of each integer and 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, respectively.

"halogen" as used herein refers to fluorine, chlorine, bromine and iodine.

"alkyl" used herein alone or as a suffix or prefix, is intended to include both branched and straight chain saturated aliphatic hydrocarbon groups having from 1 to 20, preferably 1-6, carbon atoms (or the particular number of carbon atoms if provided). For example, "C_1-6Alkyl "denotes straight-chain and branched alkyl groups having 1,2, 3,4, 5 or 6 carbon atoms. Examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, and hexyl.

"haloalkyl" or "alkyl halide" used herein alone or as a suffix or prefix, is intended to include both branched and straight chain saturated aliphatic hydrocarbon groups having at least one halogen substituent and having from 1 to 20, preferably from 1 to 6, carbon atoms (or the particular number of carbon atoms if provided). For example, "C_1-10Haloalkyl "denotes haloalkyl having 0, 1,2, 3,4, 5, 6, 7, 8, 9, 10 carbon atoms. Examples of haloalkyl groups include, but are not limited to, fluoromethyl, difluoromethyl, trifluoromethyl, chlorofluoromethyl, 1-fluoroethyl, 3-fluoropropyl, 2-chloropropyl, 3, 4-difluorobutyl, and the like.

"alkenyl" as used herein alone or as a suffix or prefix, is intended to include both branched and straight chain aliphatic hydrocarbon radicals containing alkenyl or alkene radicals having from 2 to 20, preferably 2-6, carbon atoms (or the particular number of carbon atoms if provided). For example, "C_2-6Alkenyl "denotes alkenyl having 2,3, 4, 5 or 6 carbon atoms. Examples of alkenyl groups include, but are not limited to, vinyl, allyl, 1-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 2-methylbut-2-enyl, 3-methylbut-1-enyl, 1-pentenyl, 3-pentenyl, and 4-hexenyl.

"alkynyl" used herein alone or as a suffix or prefix is intended to include both branched and straight chain aliphatic hydrocarbon radicals containing alkynyl groups or alkynes having 2 to 20, preferably 2-6 carbon atoms (or the particular number of carbon atoms if provided). For example ethynyl, propynyl (e.g., l-propynyl, 2-propynyl), 3-butynyl, pentynyl, hexynyl and 1-methylpent-2-ynyl.

The term "aryl" as used herein refers to an aromatic ring structure made up of 5 to 20 carbon atoms. For example: the aromatic ring structure containing 5, 6, 7 and 8 carbon atoms may be a monocyclic aromatic group such as phenyl; the ring structure containing 8, 9, 10, 11, 12, 13 or 14 carbon atoms may be polycyclic, for example naphthyl. The aromatic ring may be substituted at one or more ring positions with those substituents described above. The term "aryl" also includes polycyclic ring systems having two or more cyclic rings in which two or more carbons are common to two adjoining rings (the rings are "fused rings"), wherein at least one of the rings is aromatic and the other cyclic rings can be, for example, cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, and/or heterocyclyl. Examples of polycyclic rings include, but are not limited to, 2, 3-dihydro-1, 4-benzodioxine and 2, 3-dihydro-1-benzofuran.

The term "cycloalkyl" as used herein is intended to include saturated cyclic groups having the specified number of carbon atoms. These terms may include fused or bridged polycyclic ring systems. Cycloalkyl groups have 3 to 40 carbon atoms in their ring structure. In one embodiment, the cycloalkyl group has 3,4, 5, or 6 carbon atoms in its ring structure. For example, "C_3-6Cycloalkyl "denotes a group such as cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl.

As used herein, "heteroaryl" refers to a heteroaromatic heterocycle having at least one ring heteroatom (e.g., sulfur, oxygen, or nitrogen). Heteroaryl groups include monocyclic ring systems and polycyclic ring systems (e.g., having 2,3, or 4 fused rings). Examples of heteroaryl groups include, but are not limited to, pyridyl, pyrimidinyl, pyrazinyl, pyridazinyl, triazinyl, furyl, quinolinyl, isoquinolinyl, thienyl, imidazolyl, thiazolyl, indolyl, pyrrolyl, oxazolyl, benzofuryl, benzothienyl, benzothiazolyl, isoxazolyl, pyrazolyl, triazolyl, tetrazolyl, indazolyl, 1,2, 4-thiadiazolyl, isothiazolyl, benzothienyl, purinyl, carbazolyl, benzimidazolyl, benzoxazolyl, azabenzoxazolyl, imidazothiazolyl, benzo [1,4] dioxanyl, benzo [1,3] dioxolyl, and the like. In some embodiments, heteroaryl groups have from 3 to 40 carbon atoms and in other embodiments from 3 to 20 carbon atoms. In some embodiments, heteroaryl groups contain 3 to 14, 4 to 14, 3 to 7, or 5 to 6 ring-forming atoms. In some embodiments, heteroaryl has 1 to 4, 1 to 3, or 1 to 2 heteroatoms. In some embodiments, the heteroaryl group has 1 heteroatom.

The term "heterocyclyl", as used herein, unless otherwise specified, refers to a saturated, unsaturated or partially saturated monocyclic, bicyclic or tricyclic ring containing from 3 to 20 atoms, wherein 1,2, 3,4 or 5 ring atoms are selected from nitrogen, sulfur or oxygen, which may be attached through carbon or nitrogen, unless otherwise specified, wherein-CH is₂-the group is optionally replaced by-c (o) -; and wherein unless otherwise stated to the contrary, the ring nitrogen atom or the ring sulfur atom is optionally oxidized to form an N-oxide or S-oxide or the ring nitrogen atom is optionally quaternized; wherein-NH in the ring is optionally substituted with acetyl, formyl, methyl or methanesulfonyl; and the ring is optionally substituted with one or more halogens. It is understood that when the total number of S and O atoms in the heterocyclic group exceeds 1, these heteroatoms are not adjacent to each other. If the heterocyclyl is bicyclic or tricyclic, at least one ring may optionally be a heteroaromatic ring or an aromatic ring, provided that at least one ring is non-heteroaromatic. If the heterocyclic group is monocyclic, it is not necessarily aromatic. Examples of heterocyclyl groups include, but are not limited to, piperidinyl, N-acetylpiperidinyl, N-methylpiperidinyl, N-formylpiperazinyl, N-methylsulfonylpiperazinyl, homopiperazinyl, piperazinyl, azetidinyl, oxetanyl, morpholinyl, tetrahydroisoquinolinyl, tetrahydroquinolinyl, indolinyl, tetrahydropyranyl, dihydro-2H-pyranyl, tetrahydrofuranyl, tetrahydrothiopyranyl, tetrahydrothiopyran-1-oxide, tetrahydrothiopyran-1, 1-dioxide, 1H-pyridin-2-one, and 2, 5-dioxoimidazolidinyl.

In the present invention, the gellable system and the preparation method thereof are described in the patent of invention entitled "gellable system containing cyclic ether compound and preparation method and application thereof" filed on the same day by the applicant, which is incorporated herein by reference in its entirety.

In the present invention, the gellable system and the preparation method thereof are described in the patent of invention entitled "gellable system for lithium ion battery and preparation method and application thereof" filed on the same day by the applicant, which is incorporated herein by reference in its entirety.

In the present invention, the gellable system and the preparation method thereof are described in the patent of invention entitled "gellable system for lithium-sulfur battery and preparation method and application thereof" filed on the same day by the applicant, which is incorporated herein by reference in its entirety.

In the present invention, the gellable system and the preparation method thereof are described in the patent of invention entitled "gellable system containing inorganic nanoparticles and preparation method and application thereof" filed on the same day by the applicant, which is incorporated herein by reference in its entirety.

In the present invention, the gellable system and the method for preparing the gellable system are described in the patent of the invention entitled "a gel having adjustable strength and/or transition temperature, and the method for preparing the gel and the use thereof", filed on the same day by the applicant, which is incorporated herein by reference in its entirety.

In the present invention, the gellable system and the preparation method thereof are described in the patent of invention entitled "gellable system containing linear ether compound and preparation method and application thereof" filed on the same day by the applicant, which is incorporated herein by reference in its entirety.

The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are only for illustrating the present invention and are not intended to limit the scope of the present invention. Furthermore, it should be understood that various changes or modifications can be made by those skilled in the art after reading the description of the present invention, and equivalents may fall within the scope of the present invention.

Preparation example 1

Preparation of solid electrolyte film

Lithium bistrifluoromethanesulfonimide (LiTFSI): polyethylene oxide (PEO): tetraethylene glycol dimethyl ether (TEGDME): grinding and Mixing Benzophenone (MBP) according to the proportion of 10:41.3:41.2:7.5, then uniformly coating the mixture on a polytetrafluoroethylene plate to obtain a film, and carrying out ultraviolet radiation crosslinking polymerization to obtain a solid electrolyte film with the room-temperature conductivity of about 10^-3S/cm。

The specific preparation method of the Solid Electrolyte membrane can be referred to Luca Porcarlli et al SuperSoft All-Ethylene Oxide Polymer Electrolyte for Safe All-Solid lithium batteries scientific Reports,2016,6,1-14.

Example 1

(1) Preparation of gellable systems

1.2g of the lithium fluorosulfonylimide solid is weighed into a reagent bottle, and 1.5mL of a conventional lithium battery electrolyte (containing 1mol/L LiPF) is added₆The volume ratio of dimethyl carbonate (DMC) to Ethylene Carbonate (EC) is 1:1, the lithium salt is completely dissolved under magnetic stirring, 5.5mL of tetrahydropyran is added into the mixed solution, and the mixed solution is fully mixed and stands for standby.

(2) Preparation of battery material and assembly of battery

Positive electrode of lithium ion battery: uniformly mixing lithium cobaltate with conductive graphite, conductive agent acetylene black (super p) and adhesive polyvinylidene fluoride (PVDF) according to a mass ratio of 85:5:5:5, preparing the mixture into slurry by using N-methyl-pyrrolidone (NMP), uniformly coating the slurry on an aluminum foil, and drying the slurry in a vacuum oven at 120 ℃ for 24 hours for later use;

negative electrode of lithium ion battery: a lithium sheet;

and respectively soaking the positive plate and the negative plate into the prepared electrolyte solution which is not formed into the solid electrolyte, and taking out the soaked positive plate and negative plate before the solid electrolyte is formed.

A diaphragm: polypropylene (PP) porous films;

and placing the diaphragm between the positive and negative pole pieces soaked with the electrolyte, injecting the electrolyte which is not formed into the solid electrolyte into the battery, pressing and packaging the battery, standing until the electrolyte forms the solid electrolyte, and testing the electrochemical performance of the battery by using the blue-electricity battery pack.

The performance parameters of the solid electrolyte and the battery prepared are shown in table 1.

Example 2

(1) Preparation of gellable systems

Weighing 0.75g of lithium chloroaluminate and 0.1g of lithium bis (fluorosulfonyl) imide into a reagent bottle, adding 1.2mL of triethylene glycol dimethyl ether, completely dissolving the lithium chloroaluminate and the lithium bis (fluorosulfonyl) imide under magnetic stirring, adding 2.5mL of tetrahydropyran and 1.2mL of 1, 3-dioxolane, fully mixing, and standing for later use.

(2) Preparation of battery material and assembly of battery

Positive electrode of lithium-sulfur battery: uniformly mixing a carbon-sulfur composite material, a conductive agent acetylene black (super p) and a binder polyvinylidene fluoride (PVDF) according to a mass ratio of 8:1:1, preparing the mixture into slurry by using N-methyl-pyrrolidone (NMP), uniformly coating the slurry on an aluminum foil, and drying the slurry in a vacuum oven at 60 ℃ for 24 hours for later use;

negative electrode of lithium ion battery: fully mixing 90.5 parts of negative active material conductive graphite, 6 parts of acetylene black, 1 part of hydroxymethyl cellulose and 2.5 parts of styrene butadiene rubber binder by using an ethanol-water mixed solution to obtain negative slurry, coating the negative slurry on a copper foil, and drying the negative slurry in a vacuum oven at 60 ℃ for 24 hours for later use;

and respectively soaking the obtained positive plate and the negative plate into the prepared electrolyte solution which is not formed into the solid electrolyte, and taking out the soaked positive plate and the soaked negative plate before the solid electrolyte is formed.

A diaphragm: polypropylene (PP) porous films;

Example 3

The preparation methods of the positive electrode, the negative electrode and the solid electrolyte are the same as that in the example 1, the positive electrode plate and the negative electrode plate are soaked by the electrolyte before forming the solid electrolyte in the example 1, the difference is only that the solid electrolyte film prepared in the preparation example 1 is adopted to replace a polypropylene diaphragm, the electrolyte which is not formed into the solid electrolyte is not injected into the battery, the processes of packaging, standing, testing the battery and the like of the battery are the same as those in the example 1, and the performance parameters of the battery are listed in the table 1.

Example 4

The preparation methods of the positive electrode, the negative electrode and the solid electrolyte are the same as that of the embodiment 2, the positive electrode plate and the negative electrode plate are soaked by the electrolyte before forming the solid electrolyte in the embodiment 2, the difference is only that the solid electrolyte film prepared in the preparation example 1 is adopted to replace a polypropylene diaphragm, the electrolyte which is not formed into the solid electrolyte is not injected into the battery, the processes of packaging, standing, testing the battery and the like of the battery are the same as those in the embodiment 2, and the performance parameters of the battery are listed in the table 1.

Example 5

The synthesis method of the positive electrode, the negative electrode and the solid electrolyte is the same as that in the embodiment 3, except that the positive and negative electrode plates are not soaked in the electrolyte before forming the solid electrolyte, the solid electrolyte film prepared in the preparation example 1 is used for replacing a polypropylene diaphragm, the electrolyte which is not formed into the solid electrolyte is not injected into the battery for assembling the battery, the processes of standing, battery testing and the like are completely the same as those in the embodiment 3, and the performance parameters of the battery are listed in the table 1.

Example 6

The synthesis methods of the positive electrode, the negative electrode and the solid electrolyte are the same as those in the embodiment 4, the difference is only that the positive and negative electrode plates are not soaked in the electrolyte before the solid electrolyte is formed, the solid electrolyte film prepared in the preparation example 1 is used for replacing a polypropylene diaphragm, the electrolyte which is not formed into the solid electrolyte is not injected into the battery for assembling the battery, the processes of standing, battery testing and the like are completely the same as those in the embodiment 3, and the performance parameters of the battery are listed in the table 1.

Table 1 solid electrolyte properties of examples 1-6 and performance parameters of the batteries prepared

Fig. 1 is a graph of rate performance of a battery obtained in the formulation formula of example 2. As can be seen from the figure, the soaked positive and negative electrode plates can show better rate performance after a certain amount of electrolyte which is not solid electrolyte is added under the condition of the diaphragm.

Fig. 2 is a graph of rate performance of the battery obtained in the charge formula of example 4. As can be seen from the figure, the soaked positive and negative electrode plates are separated by the solid electrolyte membrane, and the cell shows better rate performance.

Fig. 3 is a graph of rate performance of a battery obtained in the charge formula of example 6. As can be seen from the figure, the positive and negative pole pieces are not soaked, the positive and negative poles are separated by a pure solid electrolyte membrane and serve as a conductor on the surface, and the multiplying power performance is poor.

As can be seen from table 1, compared with the battery assembled by the non-infiltrated positive and negative electrodes, the battery assembled by the positive and negative electrodes infiltrated by the pre-solution of the solid electrolyte shows excellent rate capability, which means that a conductive network is formed inside the infiltrated positive and negative electrodes, which is beneficial to the transmission of electrons and ions, and can bear larger rate charge and discharge, while the non-infiltrated positive and negative electrodes have no conductive network inside, and the electrochemical performance of the battery can be exerted only by the contact part of the electrode and the solid electrolyte to transmit electrons and ions, so the rate capability of the battery is poorer.

The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiment. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A preparation method of a flexible all-solid-state lithium ion secondary battery is characterized by comprising the following steps:

1) preparing a gellable system;

4) pressing the soaked or coated negative electrode, diaphragm and positive electrode into a whole in a battery pressing mould to form a pre-liquid injection all-solid-state battery, namely the flexible all-solid-state lithium ion secondary battery;

wherein the gellable system consists of the following components: lithium salt, ether compound, solvent for electrolyte, inorganic nanoparticles and additive; the mass percentage of the lithium salt is more than or equal to 20wt% and less than or equal to 30 wt%; the mass percentage of the ether compound is more than or equal to 70wt% and less than or equal to 80 wt%; the mass percentage of the solvent of the electrolyte is more than or equal to 0wt% and less than or equal to 60 wt%; the mass percentage of the inorganic nano particles is more than or equal to 0wt% and less than or equal to 20 wt%; the mass percentage of the additive is more than or equal to 0wt% and less than or equal to 20 wt%;

the ether compound is at least one of cyclic ether compound or linear ether compound; the additive is selected from one or more of polyester or blends thereof; the general formula of the linear ether compound is shown as the formula (1):

R₁—O—(R₂—O)_n—R₃formula (1)

Wherein n is an integer greater than 0;

R₂selected from straight or branched C₁-C₆An alkylene group of (a); the R is₂Carbon ofH on the atom is substituted by at least one of the following groups: alkoxy, alkylthio, cycloalkyl, cycloalkyloxy, cycloalkylthio, heterocyclyl, heterocyclyloxy, heterocyclylthio, hydroxy, mercapto, nitro, amino, halogen;

R₁and R₃The same or different, independently selected from one or more of hydrogen atom, alkyl, cycloalkyl and heterocyclic radical; the R is₁And R₃Is substituted with at least one of the following groups: alkoxy, alkylthio, cycloalkyl, cycloalkyloxy, cycloalkylthio, heterocyclyl, heterocyclyloxy, heterocyclylthio, hydroxy, mercapto, nitro, amino, halogen;

the cyclic ether compound is selected from C containing one oxygen, two oxygen, three oxygen or more oxygen₂~C₂₀One or more of cycloalkanes; the cycloalkane is a monocyclic ring, a fused ring, a spiro ring or a bridged ring;

the lithium salt is selected from one or more of lithium hexafluorophosphate, lithium hexafluoroarsenate, lithium perchlorate, lithium trifluoromethanesulfonate, lithium perfluorobutylsulfonate, lithium bistrifluoromethanesulfonylimide, lithium difluorosulfonylimide, lithium aluminate, lithium chloroaluminate, lithium fluorosulfonylimide, lithium chloride and lithium iodide.

2. A preparation method of a flexible all-solid-state lithium ion secondary battery is characterized by comprising the following steps:

1) preparing a gellable system;

wherein the gellable system consists of the following components: lithium salt, ether compound, electrolyte, inorganic nanoparticles and additive; the mass percentage of the lithium salt is more than or equal to 20wt% and less than or equal to 30 wt%; the mass percentage of the ether compound is more than or equal to 70wt% and less than or equal to 80 wt%; the mass percentage of the electrolyte is more than or equal to 0wt% and less than or equal to 60 wt%; the mass percentage of the inorganic nano particles is more than or equal to 0wt% and less than or equal to 20 wt%; the mass percentage of the additive is more than or equal to 0wt% and less than or equal to 20 wt%;

R₁—O—(R₂—O)_n—R₃formula (1)

Wherein n is an integer greater than 0;

R₂selected from straight or branched C₁-C₆An alkylene group of (a); the R is₂H on the carbon atom(s) is substituted with at least one of the following groups: alkoxy, alkylthio, cycloalkyl, cycloalkyloxy, cycloalkylthio, heterocyclyl, heterocyclyloxy, heterocyclylthio, hydroxy, mercapto, nitro, amino, halogen;

the cyclic ether compound is selected from C containing one oxygen, two oxygen, three oxygen or more oxygen₂~C₂₀One kind of cycloalkane orA plurality of types; the cycloalkane is a monocyclic ring, a fused ring, a spiro ring or a bridged ring;

3. The method according to claim 1, wherein the system further comprises a gellable polymer and/or a gellable prepolymer, and the mass percentage of the gellable polymer and/or the gellable prepolymer is less than or equal to 1 wt%.

4. The method according to claim 2, wherein the system further comprises a gellable polymer and/or a gellable prepolymer, and the mass percentage of the gellable polymer and/or the gellable prepolymer is less than or equal to 1 wt%.

5. The production method according to any one of claims 1 to 4, characterized in that the production method of the flexible all-solid-state lithium-ion secondary battery further comprises the steps of:

6. The method according to claim 1 or 3, wherein the gellable system is composed of a lithium salt, an ether compound selected from at least one of a cyclic ether compound and a linear ether compound, and a solvent for the electrolyte.

7. The method according to claim 2 or 4, wherein the gellable system is composed of a lithium salt, an ether compound selected from at least one of a cyclic ether compound and a linear ether compound, and an electrolyte.

8. The method according to any one of claims 1 to 4, wherein the gellable system is composed of a lithium salt, an ether compound selected from at least one of a cyclic ether compound and a linear ether compound, and inorganic nanoparticles.

9. The method according to claim 1 or 3, wherein the gellable system is composed of a lithium salt, an ether compound selected from at least one of a cyclic ether compound and a linear ether compound, a solvent for an electrolyte, and inorganic nanoparticles.

10. The method according to claim 2 or 4, wherein the gellable system is composed of a lithium salt, an ether compound selected from at least one of a cyclic ether compound and a linear ether compound, an electrolyte, and inorganic nanoparticles.

11. The process according to any one of claims 1 to 4, characterized in that the gellable system consists of additives of lithium salts, ethers selected from cyclic ethers, and polyesters or blends thereof.

12. The method according to any one of claims 1 to 4, wherein n is an integer of 1 to 6;

R₂selected from straight or branched C₁-C₄An alkylene group of (a);

13. The method of claim 12, wherein R is₂Selected from methyl, ethyl, propyl, isopropyl, butyl, isobutyl;

14. The method according to claim 13, wherein the linear ether compound is one or more selected from the group consisting of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol methyl ethyl ether, 1, 4-butanediol dimethyl ether, 1, 4-butanediol diethyl ether, and 1, 4-butanediol methyl ethyl ether.

15. The process according to any one of claims 1 to 4, wherein when the cycloalkane is a spiro ring or bridged ring and contains two or more oxygen atoms, the oxygen atoms are in one ring or in a plurality of rings.

16. The method according to claim 15, wherein the cyclic ether compound is at least one selected from the following first group of compounds:

。

17. the process according to any one of claims 1 to 4, wherein the cyclic ether compound is selected from the group consisting of C containing one oxygen, two oxygen, three oxygen and more oxygen₄~C₂₀Fused cycloalkane of (2).

18. The method according to claim 17, wherein the cyclic ether compound is at least one compound selected from the following second group of compounds:

。

19. the process according to any one of claims 1 to 4, wherein the cyclic ether compound is selected from the group consisting of C containing one oxygen, two oxygen, three oxygen and more oxygen₄~C₂₀Bridged cycloalkanes of (a).

20. The method according to claim 19, wherein the cyclic ether compound is at least one compound selected from the following third group of compounds:

21. the process according to any one of claims 1 to 4, wherein the cyclic ether compound is selected from the group consisting of C containing one oxygen, two oxygen, three oxygen and more oxygen₄~C₂₀Is used as the spiro cycloalkane.

22. The method according to claim 21, wherein the cyclic ether compound is at least one compound selected from the following fourth group:

。

23. the process according to any one of claims 1 to 4, wherein when the cycloalkane is a monocyclic ring or a fused ring, the hydrogen on the carbon atom on the ring is substituted with 1 or more R1 groups; when the cycloalkane is a bridged ring, the hydrogen on the carbon atom on the unbridged ring is substituted with 1 or more R1 groups; when the cycloalkane is a spiro ring, the hydrogen on the carbon atom on the ring is substituted with 1 or more R1 groups; the R1 group is selected from one of the following groups: alkyl, alkenyl, alkynyl, alkoxy, alkylthio, haloalkyl, cycloalkyl, cycloalkyloxy, cycloalkylthio, heterocyclyl, heterocyclyloxy, heterocyclylthio, aryl, aryloxy, heteroaryl, heteroaryloxy, hydroxy, mercapto, nitro, carboxy, amino, ester, halogen, acyl, aldehyde.

24. The process according to any one of claims 1 to 4, wherein the cyclic ether compound having one oxygen is selected from the group consisting of substituted or unsubstituted oxetane, substituted or unsubstituted tetrahydrofuran, substituted or unsubstituted tetrahydropyran; the number of the substituents is one or more; the substituent is a group R1 as described in claim 23.

25. The method according to claim 24, wherein the cyclic ether compound containing one oxygen is selected from the group consisting of 3, 3-dichloromethyloxetane, 2-chloromethyloxetane, 2-chloromethylpropylene oxide, 1, 3-epoxycyclohexane, 1, 4-epoxycyclohexane, tetrahydrofuran, 2-methyltetrahydrofuran, 3-methyltetrahydrofuran, tetrahydropyran, 2-methyltetrahydropyran, oxepane, oxecane, oxononane and oxecane.

26. The process according to any one of claims 1 to 4, wherein the cyclic ether compound having two oxygens is selected from the group consisting of substituted or unsubstituted 1, 3-dioxolane, substituted or unsubstituted 1, 4-dioxane; the number of the substituents is one or more; the substituent is a group R1 as described in claim 23.

27. The process according to any one of claims 1 to 4, wherein the cyclic ether compound containing three oxygens is selected from substituted or unsubstituted trioxymethylenes; the number of the substituents is one or more; the substituent is a group R1 as described in claim 23.

28. The process according to any one of claims 1 to 4, wherein the ether compound containing more oxygen is selected from the group consisting of substituted or unsubstituted 18-crown-6, substituted or unsubstituted 12-crown-4, substituted or unsubstituted 24-crown-8; the number of the substituents is one or more; the substituent is a group R1 as described in claim 23.

29. The process according to claim 1 or 3, characterized in that in step 1), the process for the preparation of the gellable system comprises in particular the following steps:

mixing an ether compound, a lithium salt, a solvent of an electrolyte, inorganic nano-particles and an additive, and stirring to obtain a mixed solution, namely the gellable system.

30. The process according to claim 2 or 4, characterized in that in step 1), the process for the preparation of the gellable system comprises in particular the following steps:

mixing an ether compound, a lithium salt, an electrolyte, inorganic nano-particles and an additive, and stirring to obtain a mixed solution, namely the gellable system.

31. The method according to claim 29, wherein the ether compound, the lithium salt, the inorganic nanoparticles, the solvent for the electrolyte, and the additive are subjected to preliminary water removal treatment.

32. The method according to claim 30, wherein the ether compound, the lithium salt, the inorganic nanoparticles, the electrolyte and the additive are subjected to preliminary water removal treatment.

33. The method of claim 31, wherein the ether compound, the lithium salt, the inorganic nanoparticles, the solvent of the electrolyte and the additive are subjected to a preliminary water removal treatment by using a molecular sieve and/or a vacuum drying method.

34. The method of claim 32, wherein the ether compound, the lithium salt, the inorganic nanoparticles, the electrolyte and the additive are subjected to a preliminary water removal treatment by using a molecular sieve and/or a vacuum drying method.

35. The production method according to any one of claims 1 to 4, wherein in steps 2) and 3), the process of pressing the positive or negative electrode into one body is performed under a dry condition.

36. The method according to any one of claims 1 to 4, wherein in steps 2) and 3), the coating is at least one selected from the group consisting of spray coating, blade coating, coating roll, and coating brush.

37. The production method according to any one of claims 1 to 4, wherein the negative electrode current collector is at least one selected from the group consisting of a copper foil, a copper alloy, a silver foil, a stainless steel sheet, and a carbon material.

38. The production method according to any one of claims 1 to 4, wherein the negative electrode material is at least one selected from a metal-based negative electrode material and an inorganic non-metal-based negative electrode material.

39. The production method according to any one of claims 1 to 4, wherein the separator is selected from a solid electrolyte separator or a polyolefin porous film produced from the gellable system.

40. The method according to any one of claims 1 to 4, wherein the positive electrode material is at least one selected from the group consisting of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, ternary nickel cobalt manganese oxide, nano-positive electrode material, blended electrode, vanadium oxide, and layered compound.

41. The method of claim 40, wherein the nano-cathode material is selected from nano-crystalline spinel LiMn₂O₄Barium-magnesium-manganese ore type MnO₂Nano-fiber and polypyrrole coated spinel type LiMn₂O₄Nanotube or polypyrrole/V₂O₅A nanocomposite material.

42. A flexible all-solid-state lithium ion secondary battery, characterized in that it is prepared by the method of any one of claims 1 to 41.

43. The flexible all solid-state lithium ion secondary battery according to claim 42, wherein the lithium ion secondary battery comprises a lithium ion battery, a lithium sulfur battery, or a lithium air battery.