WO2022057226A1 - 一种凝胶电解质前驱体及其应用 - Google Patents

一种凝胶电解质前驱体及其应用 Download PDF

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WO2022057226A1
WO2022057226A1 PCT/CN2021/082142 CN2021082142W WO2022057226A1 WO 2022057226 A1 WO2022057226 A1 WO 2022057226A1 CN 2021082142 W CN2021082142 W CN 2021082142W WO 2022057226 A1 WO2022057226 A1 WO 2022057226A1
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gel electrolyte
pole piece
preparing
gel
battery
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PCT/CN2021/082142
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English (en)
French (fr)
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吕文彬
邓素祥
陈少杰
杨红新
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蜂巢能源科技股份有限公司
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Priority to JP2022551001A priority Critical patent/JP2023515547A/ja
Priority to EP21868065.0A priority patent/EP4092798A4/en
Priority to US18/027,081 priority patent/US20240120535A9/en
Priority to KR1020227034636A priority patent/KR20220150370A/ko
Publication of WO2022057226A1 publication Critical patent/WO2022057226A1/zh

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    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0565—Polymeric materials, e.g. gel-type or solid-type
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    • C08F120/00—Homopolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride, ester, amide, imide or nitrile thereof
    • C08F120/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
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    • C08F120/44—Acrylonitrile
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    • C08F20/00—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride, ester, amide, imide or nitrile thereof
    • C08F20/02—Monocarboxylic acids having less than ten carbon atoms, Derivatives thereof
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    • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
    • C08J9/28—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof by elimination of a liquid phase from a macromolecular composition or article, e.g. drying of coagulum
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    • C08K5/43—Compounds containing sulfur bound to nitrogen
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    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D4/00—Coating compositions, e.g. paints, varnishes or lacquers, based on organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond ; Coating compositions, based on monomers of macromolecular compounds of groups C09D183/00 - C09D183/16
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    • H01M10/00—Secondary cells; Manufacture thereof
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    • H01M10/052—Li-accumulators
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    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
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    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/04—Processes of manufacture in general
    • H01M4/0402—Methods of deposition of the material
    • H01M4/0407—Methods of deposition of the material by coating on an electrolyte layer
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    • H01M4/04—Processes of manufacture in general
    • H01M4/0402—Methods of deposition of the material
    • H01M4/0416—Methods of deposition of the material involving impregnation with a solution, dispersion, paste or dry powder
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    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/04—Processes of manufacture in general
    • H01M4/0471—Processes of manufacture in general involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis
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    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/139—Processes of manufacture
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/102—Primary casings; Jackets or wrappings characterised by their shape or physical structure
    • H01M50/105—Pouches or flexible bags
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/543—Terminals
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2333/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Derivatives of such polymers
    • C08J2333/18—Homopolymers or copolymers of nitriles
    • C08J2333/20—Homopolymers or copolymers of acrylonitrile
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/021—Physical characteristics, e.g. porosity, surface area
    • H—ELECTRICITY
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    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/023—Gel electrode
    • H—ELECTRICITY
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    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0017—Non-aqueous electrolytes
    • H01M2300/0065—Solid electrolytes
    • H01M2300/0082—Organic polymers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0085—Immobilising or gelification of electrolyte
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present disclosure belongs to the field of battery materials, and relates to a gel electrolyte precursor and applications thereof.
  • Lithium Ion Battery Lithium Ion Battery.
  • commercial lithium batteries have encountered energy density bottlenecks, and it is difficult to improve in terms of high energy density.
  • solid-state batteries have been mentioned in the forefront, but solid-state batteries are difficult to develop and require high process technology.
  • semi-solid batteries came into being as a transitional product.
  • All-solid-state batteries can exist more stably inside the cells because they do not contain electrolyte components, which has attracted widespread attention.
  • all-solid-state batteries Battery technology is still immature, and there is still a long way to go before industrialization.
  • semi-solid batteries can reduce the amount of electrolyte inside the cells and improve the safety of the cells to a certain extent. The performance is currently the closest and easiest transition product to mass production.
  • Solid-state batteries can be divided into: 1 semi-solid batteries; 2 all-solid-state batteries, in which the positive and negative diaphragms of all-solid-state batteries are in solid-solid contact, and the Li+ conduction resistance is relatively large, and the current performance is difficult to reach the traditional liquid state.
  • Battery level as a transition state between traditional liquid batteries and all-solid-state batteries, semi-solid-state batteries are superior to all-solid-state batteries in terms of preparation operability, battery rate performance and cycle performance.
  • the present disclosure provides a gel electrolyte precursor and applications thereof.
  • a gel electrolyte precursor in an embodiment of the present disclosure, includes a gel skeleton monomer, a flexibility additive, a polymerization initiator and a lithium salt, and the gel skeleton monomer includes propylene Nitrile monomers.
  • Electrolyte is the substance with the lowest flash point and the lowest boiling point in the battery system. Its flash point can be as low as 80°C, and it is also the most easily ignited substance. During the use of the battery, the electrolyte is the main cause of safety problems, so reduce the amount of electrolyte. It can avoid most safety problems.
  • the gel skeleton monomer serves as the skeleton of the gel electrolyte
  • the flexible additive acts to soften the gel electrolyte, which is subsequently mixed with the electrolyte, and then in-situ polymerized and gelled
  • a gel electrolyte with an elastic porous shape is obtained; it can absorb the electrolyte inside the battery, thereby reducing the presence of free electrolyte in the battery, and improving the safety performance of the battery due to the reduction in the amount of electrolyte.
  • the absorbed electrolyte and the elastic porous morphology gel electrolyte form a new gel electrolyte, which has high electrical conductivity, ensures the rate capability of the battery, and enables the obtained battery to have high electrical performance.
  • the gel backbone monomer includes nitrile monomers, because acrylonitrile monomers have a high reactivity rate, and can form linear polymers in a short time, and the linear polymers are intertwined with each other. Forms a network structure, thus eliminating the need for cross-linking agents.
  • the acrylonitrile-based monomer contains double bonds, and in the process of in-situ polymerization and gelation, the double bonds are opened into chains under the action of a polymer initiator, and are baked in a later stage. During the process, the volatile components are removed by baking, the volatile components form pores in the gel electrolyte, and the polymer skeleton structure is retained to form a skeleton structure with elasticity and pores. Moreover, the acrylonitrile-based monomer is used as a skeleton material, and the acrylonitrile-based polymer obtained by in-situ polymerization and gelation has good flame retardancy and high voltage resistance, thereby further improving the safety performance of the battery.
  • the acrylonitrile monomers include acrylonitrile, allyl nitrile, 2-bromoacrylonitrile, 1-cyclohexeneacetonitrile, 3,3-diphenylacrylonitrile, 3-cyclohexene -1-Nitrile, 1-cyclopenteneacetonitrile, 2-ethoxyacrylonitrile, 1,2-dicyanocyclobutene, cyclovinyl-1,2-dicarbonitrile, diaminomaleonitrile, 3, 3-dimethoxy-2-acrylonitrile, ethoxymethylene malononitrile, 2-tert-butyl maleonitrile, 2,2,3,4,4-pentafluoro-3-butenenitrile, At least one of 1-cyano-2-propenyl acetate and benzallyl malononitrile.
  • the acrylonitrile-based monomer is acrylonitrile.
  • the gel backbone monomers include acrylonitrile-based monomers, which form acrylonitrile-based polymers (such as polyacrylonitrile) in the process of in-situ polymerization and gelation when mixed with an electrolyte, and polyacrylonitrile has good properties. Flame retardant performance, and high voltage resistance, can significantly improve the safety of the battery during the use of the battery.
  • the gel electrolyte precursor after the gel electrolyte precursor is mixed with the electrolyte, it can be uniformly dip-coated on the positive electrode and/or the negative electrode.
  • the first effect and rate performance of the semi-solid battery obtained by using the gel electrolyte precursor described in the present disclosure are basically the same as those of the liquid battery, and the electrical properties of the battery are not affected.
  • the gel electrolyte obtained from the colloidal precursor can fix the electrolyte in the battery, so that the electrolyte cannot move freely in the battery, reducing the free electrolyte outside the bare cell, and reducing the safety problem in the safety test, Its safety is significantly better than that of liquid batteries.
  • the flexibility additive is selected from succinonitrile and/or ionic liquid.
  • the ionic liquid includes 1-methyl-1-propylpiperidine bis(trifluoromethanesulfonimide) salt (PP13TFSI), 1-butyl-1-methylpiperidine bis(trifluoromethanesulfonimide) Fluoromethanesulfonyl)imide (PP14TFSI), 1-butyl-1-methylpyrrolidine bis(trifluoromethanesulfonyl)imide (Pyr14TFSI), 1-methyl-1-propylpyrrolidinium Bis(fluorosulfonyl)imide (Pyr13FSI), 1-propyl-1-methylpyrrolidine bis-trifluoromethanesulfonimide salt (Pyr13TFSI), 1-ethyl-3-methylimidazole bis-trifluoromethane At least one of sulfonimide salt ([EMIM]TFSI) and 1-ethyl-3-methylimidazolium tetrafluoroborate
  • the flexible additive adopts succinonitrile and/or ionic liquid, which has the following characteristics: 1) Due to the high boiling points of succinonitrile and ionic liquid, the vapor pressure changes less with temperature, and It basically does not volatilize during the drying process, and basically remains in the system after other low-boiling solvents are completely volatilized; 2) The viscosity of succinonitrile and ionic liquid is relatively large, so it can play a role in softening the electrolyte; 3) D Dinitrile and ionic liquid substances themselves are inflammable and can improve the safety of electrolyte materials; therefore, the use of succinonitrile and ionic liquids can soften the electrolyte materials, and increasing the flexibility of the electrolyte will reduce the glass transition temperature of the electrolyte. So as to achieve the effect of improving the conductivity.
  • the polymerization initiator is selected from azobisisobutyronitrile (AIBN) and/or azobisisoheptanenitrile (V65).
  • the polymerization initiator is azobisisobutyronitrile.
  • the lithium salt is selected from lithium perchlorate (LiClO 4 ), lithium bistrifluoromethanesulfonimide (LiTFSI), lithium bisfluorosulfonimide (LiFSI), bisoxalic acid boric acid At least one of lithium (LiBOB) and lithium tetrafluoroborate (LiBF 4 ).
  • the lithium salt is lithium bistrifluoromethanesulfonimide.
  • the gel electrolyte precursor includes the above-mentioned lithium salt, which can dissolve and dissociate lithium ions in the gel electrolyte precursor, and has high thermal stability, which is convenient for The formation of stable gel electrolytes with high electrical conductivity enables lithium-ion batteries to have high rate capability.
  • Electrolyte conductance in a lithium ion battery requires freely movable lithium ions.
  • the role of the lithium salt in the present disclosure is to provide mobile lithium ions, and the use of lithium salts to provide a lithium ion source is now a common method.
  • the commonality of the lithium ion source is naturally that it contains lithium ions, and can dissolve and dissociate lithium ions in the gel electrolyte precursor.
  • lithium salts can be screened according to the size of their anions, and the degree of dissociation and conductivity have both The difference is that the lithium salt in the present disclosure needs to be stable at high temperature, and the above lithium salts are relatively stable at high temperature; while lithium hexafluorophosphate has the problem of high temperature instability and easy decomposition, so it is not recommended to use.
  • the gel electrolyte precursor includes the following components based on the sum of the mass of the gel backbone monomer, the flexibility additive and the polymerization initiator as 100%:
  • Polymerization initiator 1-10% in the gel precursor, the mass of the gel skeleton monomer, the flexibility additive and the polymerization initiator is 100%, and in the gel electrolyte precursor, the gel skeleton is The mass percentage of the monomer is 30-80%, such as 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70% or 75%, etc.
  • the mass percentage of the flexible additive is 20 to 60%, such as 25%, 30%, 35%, 40%, 45%, 50% or 55%, etc.
  • the mass percentage of the polymerization initiator is 1 to 10%, such as 2%, 3%, 5% %, 7% or 9% etc.
  • the ratio of the molar amount of the lithium salt to the volume of the gel skeleton monomer is 0.1-2 mol/L, such as 0.3 mol/L, 0.5 mol/L, 0.8 mol/L, 1 mol/L. L, 1.2mol/L, 1.5mol/L or 1.8mol/L, etc.
  • the ratio of the molar amount of the lithium salt to the volume of the gel skeleton monomer is 0.5-1.5 mol/L.
  • each component of the gel electrolyte precursor satisfies the above-mentioned composition, which is conducive to subsequent in-situ polymerization and gelation, and baking to form an elastic porous shape; further, it is beneficial to its use in batteries It absorbs the electrolyte to form a new gel electrolyte, maintains high conductivity, and ensures the rate performance of the battery; in addition, it reduces the amount of electrolyte and free electrolyte outside the bare cell, and improves the safety performance of the battery.
  • the gel electrolyte precursor includes the following components based on the sum of the mass of the gel backbone monomer, the flexibility additive and the polymerization initiator as 100%:
  • the mass percentage of the gel skeleton monomer is 50% to 65%, such as 55%, 60% or 65%, etc.
  • the mass percentage of the flexible additive is 30 to 45%, such as 33%, 35%, 38%, 40%, 42% or 44%, etc.
  • the molar content of the polymerization initiator is 2-5%, for example, 3%, 4%, and the like.
  • a solution for preparing a gel electrolyte is provided, wherein the solution includes the gel electrolyte precursor and an electrolyte solution according to an embodiment.
  • a gel electrolyte precursor is mixed with an electrolyte, and gelled to obtain a gel electrolyte.
  • the ratio of the electrolyte is not limited here, for example, the solvent of the electrolyte
  • the mass ratio of the gel electrolyte precursor to the electrolyte in the solution for preparing the gel electrolyte is 0.1:9.9 ⁇ 9.9:0.1, such as 1:9, 2:8, 3:7 , 5:5, 6:4, 7:3, 8:2 or 9:1, etc.
  • the mass ratio of the gel electrolyte precursor to the electrolyte in the solution for preparing the gel electrolyte is 4:6-6:4.
  • the solution for preparing the gel electrolyte is prepared by the following method, the method includes mixing the precursor of the gel electrolyte with an electrolyte to obtain the solution for preparing the gel electrolyte .
  • a method for preparing a gel electrolyte includes subjecting the solution for preparing a gel electrolyte as described in an embodiment to gelation by in-situ polymerization, and then baking to obtain a the gel electrolyte.
  • the gel electrolyte precursor is mixed with an electrolyte, and then in-situ polymerized, gelled, and baked to obtain a gel electrolyte with an elastic porous shape, which can be absorbed inside the battery. electrolyte, thereby reducing the presence of free electrolyte in the battery and improving the safety of the battery.
  • the temperature of the in-situ polymerization and gelation is 70-75°C, for example, 71°C, 72°C, 73°C, or 74°C.
  • the baking is vacuum baking.
  • the vacuum degree of the vacuum baking is less than or equal to 0.1 kPa; for example, 0.01 kPa, 0.03 kPa, 0.05 kPa, or 0.08 kPa, and the like.
  • the baking temperature is 80-85°C, for example, 81°C, 82°C, 83°C, or 84°C.
  • the above-mentioned gel electrolyte precursor is mixed with an electrolyte to perform in-situ polymerization and gelation, and then part of the solvent in the electrolyte is removed by baking and volatilization to form an elastic porous gel electrolyte, which is composed of To assemble a semi-solid battery, just add a small amount of electrolyte.
  • a gel electrolyte prepared by the method described in the embodiment is provided, wherein the gel electrolyte is in a porous form.
  • the gel electrolyte is in an elastic porous form.
  • the gel electrolyte in the elastic porous shape can absorb the electrolyte, thereby reducing the presence of free electrolyte in the battery.
  • the absorbed electrolyte and the gel electrolyte in the elastic porous shape form a new gel electrolyte, which has high electrical conductivity to ensure The high electrical conductivity of the electrolyte ensures the rate performance and electrical performance of the battery, and it reduces the amount of electrolyte, and achieves the purpose of improving the safety of the battery.
  • the gel electrolyte described in the present disclosure can be applied to the positive electrode and/or the negative electrode of the battery, for example, both the positive electrode and the negative electrode adopt the gel electrolyte described in the present disclosure, any one of the positive electrode or the negative electrode adopts the gel electrolyte described in the present disclosure, and the other one adopts the gel electrolyte described in the present disclosure.
  • the pole piece adopts other electrolyte for example, the other pole piece adopts other gel electrolyte, does not add gel electrolyte or adopts other type of electrolyte, etc.
  • a method for preparing a pole piece containing a gel electrolyte includes: coating the pole piece with the solution for preparing a gel electrolyte according to an embodiment, and in-situ Polymerization, drying, and obtaining a pole piece containing a gel electrolyte.
  • the pole piece includes a positive pole piece and/or a negative pole piece.
  • the pole piece here is the prepared positive pole piece and/or negative pole piece.
  • the gel electrolyte precursor can be applied to the positive and negative electrode materials of any lithium ion battery
  • the positive electrode active material can be lithium cobalt oxide (LCO), lithium nickel oxide (LNO), Lithium manganate (LMO), nickel cobalt manganese (NCM) or high nickel system
  • the negative electrode active material can be artificial graphite, natural graphite, silicon oxygen, silicon carbon or lithium metal systems.
  • the method of coating includes dip coating.
  • the method of dip coating includes placing the pole piece in a solution for preparing a gel electrolyte.
  • the pole piece is dipped in a solution encapsulated in a solution for preparing a gel electrolyte, and in this process, the pole piece fully absorbs the gel through capillary effect Mixed solution of electrolyte precursor and electrolyte; after enough time, take out the pole piece from the aluminum plastic film, wipe the surface of the pole piece to complete the dip coating of the pole piece; the dip coating method of the positive pole piece and the negative pole piece is the same.
  • the pole pieces are placed vertically in the solution used to prepare the gel electrolyte.
  • the method further includes wiping the surface of the pole piece.
  • the wiping is done with clean paper.
  • the temperature of the in-situ polymerization is 70-75°C, such as 70°C, 71°C, 72°C, 73°C, 74°C, or 75°C, and the like.
  • the in-situ polymerization temperature is controlled within the above-mentioned range, which is conducive to rapid gelation.
  • the polymerization temperature is too low, the gelation process is longer, and the engineering time and engineering ability will be affected. Influence; when the polymerization temperature is too high, the polymerization reaction is too violent, and the polymerization cannot be fully completed, and the gel may not be formed, and a good gel system cannot be formed, which will be detrimental to the safety of the battery.
  • the in-situ polymerization conditions of the gel electrolyte of the positive pole piece can be different.
  • the in-situ polymerization condition of the negative pole piece is 75°C in-situ polymerization for 24h
  • the in-situ polymerization condition of the positive pole piece is 75°C in-situ polymerization for 17h.
  • the dip-coated pole piece is placed in an aluminum-plastic film before the in-situ polymerization starts; here, the aluminum-plastic film is a clean aluminum-plastic film.
  • the time of the in-situ polymerization is 16-32h, such as 17h, 19h, 21h, 24h, 28h or 30h, and the like.
  • the method further includes wiping the tabs of the pole pieces.
  • the solvent used for wiping the tabs of the pole piece is dimethyl sulfoxide.
  • the precursor may stick to the tabs, which will affect the subsequent welding performance.
  • the above-mentioned solvent is used to wipe the tabs after in-situ polymerization, which is conducive to ensuring the quality of subsequent welding. If you can find a way not to stick to the tabs, this step can be removed.
  • the in-situ polymerization further includes drying.
  • the in-situ polymerized pole piece is wrapped with dust-free paper before the drying.
  • the drying process of the positive pole piece and the negative pole piece is not carried out in the same oven to avoid cross contamination; and after drying, if it is not used immediately, it needs to be packaged with aluminum plastic film to avoid absorbing moisture in the air.
  • the drying is vacuum drying.
  • the drying temperature is 80-85°C, for example, 82°C, 84°C, or 85°C.
  • vacuum drying is performed at the above temperature to remove part of the solvent in the electrolyte, thereby forming a pole piece containing an elastic porous state gel electrolyte.
  • the temperature is too low, the low-boiling point components are not completely volatilized and cannot be formed well. Porous structure, after adding the electrolyte in the later stage, the electrolyte cannot be completely infiltrated, the conductivity of the battery system is low, and the rate performance will be affected; when the temperature is too high, the structure of the lithium salt in the electrolyte will be destroyed, and the elasticity of the electrolyte will be destroyed. The electrolyte becomes brittle and the conductivity decreases.
  • the method includes the steps of:
  • step (2) Put the dip-coated pole piece in step (1) in an aluminum plastic film, put it at 70-75°C for in-situ polymerization for 24 hours, then take out the pole piece and wipe the pole ears with dimethyl sulfoxide ;
  • step (3) wrapping the pole piece after in-situ polymerization in step (2) with dust-free paper, placing it in an oven, and vacuum drying at 80-85° C. to obtain a pole piece containing a gel electrolyte.
  • a pole piece comprising a gel electrolyte prepared by the method described in the embodiment is provided.
  • a semi-solid battery is provided, and at least one of the positive electrode or the negative electrode of the semi-solid battery adopts the electrode including the gel electrolyte as described in the embodiment.
  • the semi-solid battery includes at least one of a soft pack battery, a cylindrical battery and a square aluminum shell battery.
  • the semi-solid battery is a soft pack battery.
  • the assembly method of the semi-solid battery includes a lamination type and/or a winding type.
  • the manufacturing method of the semi-solid battery includes assembling the positive pole piece and the negative pole piece by winding or laminating, then injecting liquid, standing at 40-50° C., and then forming into the battery.
  • Semi-solid battery; the process of liquid injection and chemical formation is not limited here.
  • Fig. 1 is the process flow of the dip coating process of positive pole piece in one embodiment of the present disclosure
  • FIG. 2 is a process flow diagram of in-situ polymerization and gelation of positive pole pieces after dip-coating in one embodiment of the present disclosure
  • FIG. 3 is a SEM+EDX picture of the surface of a positive electrode plate including a gel electrolyte in an embodiment of the present disclosure
  • FIG. 4 is a SEM image of the surface of a positive electrode sheet including a gel electrolyte according to an embodiment of the present disclosure, wherein the boxed area is marked as area A, that is, the lower area;
  • FIG. 5 is a SEM image of the surface of a positive electrode sheet including a gel electrolyte in an embodiment of the present disclosure, wherein the boxed area is marked as area B, that is, the upper area;
  • FIG. 7 is an optical image of a needle stick safety test of a semi-solid battery (PVCA gel state NCM-Gr battery) in one embodiment of the present disclosure.
  • a method for preparing a positive electrode sheet containing a gel electrolyte is provided.
  • the schematic diagram of the preparation process of the method is shown in FIG. 1 and FIG. 2 , including the following steps:
  • step (c) placing the positive pole piece vertically in the aluminum plastic film of step (b) to perform dip coating of the positive pole piece;
  • step (e) place the positive electrode piece in step (d) again in a new aluminum plastic film, and perform in-situ polymerization (for example, in-situ polymerization at 75°C for 24h);
  • step (g) vacuum-drying the positive electrode sheet of step (f) to obtain a positive electrode electrode sheet containing a gel electrolyte; the gel electrolyte is in an elastic porous state.
  • the gel electrolyte precursor includes the following components: a gel skeleton monomer, a flexible additive, a polymerization initiator and a lithium salt;
  • the gel backbone monomer is acrylonitrile monomer
  • the flexibility additive is succinonitrile
  • the polymerization initiator is azobisisobutyronitrile
  • the lithium salt is lithium bistrifluoromethanesulfonimide.
  • the gel electrolyte precursor includes the following components:
  • the ratio of the molar amount of the lithium salt to the volume of the gel skeleton monomer is 1 mol/L;
  • the mass ratio of the gel electrolyte precursor mixed with the electrolyte is 1:1;
  • Positive pole piece the current collector is 12 ⁇ m aluminum foil, the positive electrode active material is NCM622, the binder is PVDF 5130, and the conductive agent SP;
  • Negative pole piece the current collector is 8 ⁇ m copper foil, the negative electrode active material is a mixture of artificial graphite and hard carbon, the conductive agent is SP, and the binder is CMC&SBR;
  • step (2) Put the negative pole piece after dip-coating in step (1) in a new aluminum plastic film, and put it at 75°C for in-situ polymerization for 24 hours, then take out the pole piece and wipe the pole piece with dimethyl sulfoxide. Ear;
  • step (3) Wrap the pole piece after in-situ polymerization in step (2) with dust-free paper, put it in an oven, and vacuum dry at 85° C. for 24 hours to obtain a pole piece containing a gel electrolyte.
  • the only difference between the preparation method of the positive electrode sheet containing the gel electrolyte and the negative electrode electrode sheet is that the in-situ polymerization conditions are replaced by in-situ polymerization at 75°C for 17 h; and different ovens are used to avoid cross-contamination, and other conditions are the same.
  • a semi-solid battery is prepared by lamination. After lamination, it is injected with liquid (1.5g/Ah) and allowed to stand at 45°C to form a semi-solid battery, which is recorded as polyacrylonitrile (PAN-SN) gel. state NCM-Gr battery.
  • PAN-SN polyacrylonitrile
  • the uniformity of the gel formation of the negative electrode sheet containing the gel electrolyte obtained in Example 1 was tested, and the test method was SEM+EDX; the S element in LiTFSI was used for calibration, and its electron microscope image was shown in Figure 3, It can be seen from the SEM+EDX pictures that the S element is uniformly distributed, and the gel in the pole piece is uniformly distributed from top to bottom; the element percentage is used to calibrate, as shown in Figure 4 (lower area) and Figure 5 (upper area) , the same pole piece, the S element content of the upper and lower positions are respectively the upper part: 4.1%, the lower part: 4.01%; in the range of 4 ⁇ 0.2%; the gel formation is very uniform.
  • the gel electrolyte precursor includes the following components based on the sum of the mass of the gel backbone monomer, the flexibility additive and the polymerization initiator being 100%:
  • the ratio of the molar amount of the lithium salt to the volume of the gel skeleton monomer is 2mol/L;
  • the gel electrolyte precursor includes the following components based on the sum of the mass of the gel backbone monomer, the flexibility additive and the polymerization initiator being 100%:
  • the ratio of the molar amount of the lithium salt to the volume of the gel skeleton monomer is 0.1 mol/L;
  • the gel electrolyte precursor includes the following components based on the sum of the mass of the gel backbone monomer, the flexibility additive and the polymerization initiator being 100%:
  • the ratio of the molar amount of the lithium salt to the volume of the gel skeleton monomer is 1.5mol/L;
  • Example 1 The difference between this example and Example 1 is that the mass ratio of the gel electrolyte precursor to the electrolyte is replaced from 1:1 to 9:1, and other parameters and conditions are exactly the same as those in Example 1.
  • Example 1 The difference between this example and Example 1 is that the mass ratio of the gel electrolyte precursor to the electrolyte is replaced from 1:1 to 1:9, and other parameters and conditions are exactly the same as those in Example 1.
  • Example 1 The difference between this example and Example 1 is that the quality of the flexible additive is replaced with ionic liquid, and the composition of the ionic liquid is 1-butyl-1-methylpiperidine bis(trifluoromethanesulfonyl)imide salt ( PP14TFSI), other parameters and conditions were exactly the same as in Example 1.
  • ionic liquid is 1-butyl-1-methylpiperidine bis(trifluoromethanesulfonyl)imide salt ( PP14TFSI)
  • Example 1 The difference between this example and Example 1 is that the equimolar amount of lithium salt in the precursor is replaced with lithium perchlorate, and other parameters and conditions are exactly the same as those in Example 1.
  • Example 1 The difference between this example and Example 1 is that the equimolar amount of lithium salt in the precursor is replaced with lithium tetrafluoroborate, and other parameters and conditions are exactly the same as those in Example 1.
  • Example 1 The only difference between this example and Example 1 is that a coating method is used in the preparation process of the negative pole piece and the positive pole piece containing the gel electrolyte, that is, dip coating is not used; The mixed solution is coated on the surface of the pole piece, then in-situ polymerized and baked to obtain a negative pole piece and a positive pole piece containing a gel electrolyte.
  • a coating method is used in the preparation process of the negative pole piece and the positive pole piece containing the gel electrolyte, that is, dip coating is not used;
  • the mixed solution is coated on the surface of the pole piece, then in-situ polymerized and baked to obtain a negative pole piece and a positive pole piece containing a gel electrolyte.
  • Other parameters and conditions are exactly the same as those in Example 1.
  • a coating method was used to coat the gel electrolyte precursor on the surface of the positive electrode.
  • the results of elemental analysis using SEM+EDX showed that the surface of the electrode had a high content of gel electrolyte, and the bottom of the electrode (near the bottom of the electrode) Current collector side) electrolyte content ⁇ 0%; after dip coating, the content of the upper and bottom of the pole piece is very uneven, and the purpose of complete infiltration is not achieved.
  • Example 1 The only difference between this comparative example and Example 1 is that the positive electrode and negative electrode do not contain gel electrolyte, and the fabricated positive electrode and negative electrode are directly laminated, and then injected with liquid (2.65g/Ah) , stand, and form into a liquid battery, which is denoted as a liquid NCM-Gr (positive electrode ternary material, negative electrode graphite and hard carbon) battery.
  • a liquid NCM-Gr positive electrode ternary material, negative electrode graphite and hard carbon
  • Example 1 The optical pictures of the battery acupuncture safety test in Comparative Example 1 and Example 1 are shown in Figure 6 and Figure 7, respectively.
  • Example 1 the semi-solid battery can pass the acupuncture test, but in Comparative Example 1, acupuncture caught fire; This shows that the semi-solid battery obtained by using the gel electrolyte precursor of the present disclosure has higher safety.
  • Example 1 The difference between this comparative example and Example 1 is that the gel electrolyte precursor does not contain a flexible additive, and other parameters and conditions are exactly the same as those in Example 1.
  • Example 1 The difference between this comparative example and Example 1 is that the gel electrolyte precursor does not contain lithium salt, and other parameters and conditions are exactly the same as those in Example 1.
  • Example 1 The difference between this comparative example and Example 1 is that the lithium salt in Example 1 is replaced by LiPF6, and other parameters and conditions are exactly the same as those in Example 1.
  • This comparative example uses LiPF6 as the lithium salt of the gel electrolyte precursor. After gelation at 75 °C, the gel cannot be completely formed, and the material part is still liquid, and the color becomes dark brown.
  • the battery obtained in the embodiment and the comparative example is carried out to the test of rate performance, first effect, cycle performance and safety (needle punch test), and the test results are as shown in Table 5:
  • the rate performance of 1C/0.33C is obtained by the test, and the test parameters of rate performance of 1C/0.5C, 1C/1C and 1C/2C under other conditions refer to the above conditions.
  • the first effect test conditions the ambient temperature is 25 °C;
  • Cycle performance test conditions the test temperature is 25 °C;
  • the gel electrolyte obtained by in-situ polymerization and coagulation of the gel electrolyte precursor described in the present disclosure mixed with the electrolyte solution significantly improves the safety of the battery assembled from the gel electrolyte, and the obtained semi-solid battery has a
  • the electrical performance can be similar to that of the liquid battery, and the effect of improving the safety of the battery is achieved while maintaining high electrical performance.
  • the content of each component in the gel electrolyte precursor described in the present disclosure will affect the performance of the semi-solid battery.
  • the electrical properties of the obtained semi-solid battery The improvement of safety performance and safety performance is more obvious: the gel electrolyte precursor includes the following components based on the sum of the mass of the gel skeleton monomer, the flexible additive and the polymerization initiator as 100%: the mass of the gel skeleton monomer is 100%.
  • the sub-content is 50-65%, the mass percentage of the flexible additive is 30-45%, and the mass percentage of the polymerization initiator is 2-5%.
  • Comparing Example 1 and Comparative Example 1 it can be seen that the battery assembled with the gel electrolyte obtained from the gel electrolyte precursor described in the present disclosure can achieve electrical performance similar to that of the liquid battery, and has higher safety.
  • Comparative Example 2 there is no flexible additive, so gel cannot be formed.
  • the polymerization of backbone monomers will increase the crystallinity of the material, resulting in pulverization and precipitation of the material;
  • Comparative Example 3 does not contain lithium salt, and gel can be formed , but the conductivity of the gel system will decrease, the performance will be worse than that of adding lithium salt, and the safety will also become worse.

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Abstract

本公开提供了一种凝胶电解质前驱体及其应用，凝胶电解质前驱体包括凝胶骨架单体、柔性添加剂、聚合引发剂及锂盐，凝胶骨架单体包括丙烯腈类单体。采用其应用于半固态电池具有良好的电性能，还减少了电解液的用量，丙烯腈类单体原位聚合凝胶化得到的丙烯腈类聚合物具有很好的阻燃性能且耐高电压，提高了电池的安全性能。

Description

一种凝胶电解质前驱体及其应用 技术领域
本公开属于电池材料领域，涉及一种凝胶电解质前驱体及其应用。
背景技术
随着社会的快速发展和进步，能源短缺及环境污染问题日益严重，人们对于清洁能源需求变得日益重视；同时，新能源汽车日益普及，能源动力发展日益扩大，促使人们开发更高能量密度的锂离子电池。目前商用锂电池已经出现能量密度的瓶颈，在高能量密度方面很难有提升，固态电池作为下一代电池已经被提到了前沿位置，但是固态电池研发难度大，工艺要求较高，目前还不能马上实现量产，因此半固态电池作为一种过渡产品应运而生。
新能源汽车自燃现象层出不穷，人们一直尝试开发更加安全可靠的新型电池，全固态电池因其不含电解液成分，在电芯内部可以更加稳定地存在，引起人们的普遍关注；但是，目前全固态电池技术尚不成熟，距离工业化还有很长的路要走，半固态电池作为液态电池与全固态电池的中间产品，可以减少电芯内部电解液的用量，在一定程度上改善电芯的安全性能，是目前最接近也最易实现量产的过渡产品。
固态电池从制备方法上划分主要可以分为：①半固态电池；②全固态电池，其中全固态电池正负极隔膜之间是固固接触，Li+传导阻力较大，目前性能很难达到传统液态电池水准；半固态电池作为传统液态电池到全固态电池中间的过渡态，在制备的可操作性、电池的倍率性能及循环性能都优于全固态电池。
半固态电池作为传统液态电池到全固态电池的过渡产品，需要兼具传统液态电池优良的倍率及循环性能，同时又要有全固态电池的安全性能，为了提高 电池的安全性能就要尽可能地减少电解液的用量，电解液是电池体系内部闪点最低，沸点最低的物质，也是最容易燃烧的物质，所以减少液态电解液的使用量，是提高电池安全性的重要手段，凝胶态电解质作为安全的电解质非常受到关注。
因此，开发一种适于用半固态电池使得电池具有与传统液态电池相当的电性能，且具有更高的安全性的凝胶电解质前驱体仍具有重要意义。
公开内容
本公开提供了一种凝胶电解质前驱体及其应用。
本公开在一实施例中提供了一种凝胶电解质前驱体，所述凝胶电解质前驱体包括凝胶骨架单体、柔性添加剂、聚合引发剂及锂盐，所述凝胶骨架单体包括丙烯腈类单体。
电解液是电池体系内部闪点最低、沸点最低的物质，其闪点最低可以到80℃，也是最容易点燃的物质，在电池使用过程中，电解液是引发安全问题的主因，所以减少电解液的使用量，能避免绝大多数安全问题。
在本公开提供的一实施例中，凝胶骨架单体作为凝胶电解质的骨架，柔性添加剂起到柔化凝胶电解质的作用，后续将其与电解液混合，之后原位聚合凝胶化、烘烤后得到弹性多孔形态的凝胶电解质；其在电池内部能吸收电解液，从而减少电池中游离电解液的存在，由于减少了电解液的用量，进而提高了电池的安全性能。同时，被吸收的电解液与弹性多孔形态凝胶电解质形成新的凝胶电解质，其具有高的电导率，保证了电池的倍率性能，使所得电池具有高的电性能。
在本公开提供的一实施例中，所述凝胶骨架单体包括腈类单体，因为丙烯腈类单体本身竞聚率较高，在短时间可以形成线性高分子，线性高分子互相缠绕形成网状结构，因此无需采用交联剂。
在本公开提供的一实施例中，丙烯腈类单体包含双键，在原位聚合凝胶化的过程中，其在聚合物引发剂的作用下双键打开成链状，在后期烘烤过程中将易挥发组分烘烤除去，易挥发组分在凝胶电解质中形成孔隙，聚合物骨架结构 保留，形成具有弹性和孔隙的骨架结构。而且，丙烯腈类单体作为骨架材料，其原位聚合凝胶化得到的丙烯腈类聚合物具有很好的阻燃性能，而且耐高电压，进而达到进一步提高电池的安全性能的目的。
在一实施例中，所述丙烯腈类单体包括丙烯腈、烯丙基腈、2-溴丙烯腈、1-环己烯乙腈、3,3-二苯基丙烯腈、3-环己烯-1-腈、1-环戊烯乙腈、2-乙氧基丙烯腈、1,2-二氰基环丁烯、环乙烯基-1,2-二腈、二氨基马来腈、3,3-二甲氧基-2-丙烯腈、乙氧基亚甲基丙二腈、2-叔丁基顺丁烯二腈、2,2,3,4,4-五氟-3-丁烯腈、1-氰基-2-丙烯基乙酸酯及苄烯丙二腈中的至少一种。
在一实施例中，所述丙烯腈类单体为丙烯腈。
所述凝胶骨架单体包括丙烯腈类单体，其在与电解液混合，原位聚合凝胶化的过程中形成丙烯腈类聚合物(例如聚丙烯腈)，聚丙烯腈具有很好的阻燃性能，而且耐高电压，在电池使用过程中，能明显改善电池的安全性。
在本公开提供的一实施例中，凝胶电解质前驱体与电解液混合后，其能均匀地浸涂在正极极片和/或负极极片上。
在本公开提供的一实施例中，采用本公开所述凝胶电解质前驱体得到的半固态电池的首效、倍率性能与液态电池基本一致，没有影响电池的电性能，而本公开所述凝胶态前驱体得到的凝胶态电解质能固定电池中的电解液，使得电解液在电池内不能自由移动，减少了裸电芯外部的游离电解液，在安全测试中，减少了安全性问题，其安全性明显优于液态电池。
在一实施例中，所述柔性添加剂选自丁二腈和/或离子液体。
在一实施例中，所述离子液体包括1-甲基-1-丙基哌啶双三氟甲基磺酰亚胺盐(PP13TFSI)、1-丁基-1-甲基哌啶双(三氟甲磺酰基)亚胺盐(PP14TFSI)、1-丁基-1-甲基吡咯烷双(三氟甲磺酰)亚胺盐(Pyr14TFSI)、1-甲基-1-丙基吡咯烷鎓双(氟磺酰)亚胺(Pyr13FSI)、1-丙基-1-甲基吡咯烷双三氟甲磺酰亚胺盐(Pyr13TFSI)、1-乙基-3-甲基咪唑双三氟甲磺酰亚胺盐([EMIM]TFSI)及1-乙基-3-甲基咪唑四氟硼酸盐([EMIM]BF4)中的至少一种。
在本公开提供的一实施例中，柔性添加剂采用丁二腈和/或离子液体，其具有以下特点：1)由于丁二腈和离子液体的沸点较高，蒸气压随温度变化较小，在干燥过程中基本不会发生挥发，在其他低沸点的溶剂挥发完全后基本保留在体系中；2)丁二腈和离子液体的粘度较大，所以可以起到柔化电解质的作用； 3)丁二腈和离子液体类物质本身难燃，可以提高电解质材料安全性；因此，采用丁二腈和离子液体可以起到柔化电解质材料的作用，增加电解质的柔韧性会降低电解质的玻璃化温度，从而达到提高电导率的作用。
在一实施例中，所述聚合引发剂选自偶氮二异丁腈(AIBN)和/或偶氮二异庚腈(V65)。
在一实施例中，所述聚合引发剂为偶氮二异丁腈。
在一实施例中，所述锂盐选自高氯酸锂(LiClO 4)、双三氟甲烷磺酰亚胺锂(LiTFSI)、双氟磺酰亚胺锂(LiFSI)、双乙二酸硼酸锂(LiBOB)及四氟硼酸锂(LiBF 4)中的至少一种。
在一实施例中，所述锂盐为双三氟甲烷磺酰亚胺锂。
在本公开提供的一实施例中，所述凝胶电解质前驱体中包含上述锂盐，其能在凝胶电解质前驱体中溶解并解离出锂离子，且具有较高的热稳定性，便于形成稳定的凝胶电解质，且具有高的电导率，使得锂离子电池具有高的倍率性能。
锂离子电池中电解质电导需要有能够自由移动的锂离子，本公开所述锂盐的作用是提供可迁移的锂离子，使用锂盐提供锂离子源是现在通用的方法。锂离子源的共性自然是要含有锂离子，并在凝胶电解质前驱体中能溶解并解离出锂离子，其中，不同锂盐可以根据其阴离子大小进行筛选，解离程度及电导率都有所不同，而且本公开中锂盐需要高温稳定，以上锂盐在高温中都较稳定；而六氟磷酸锂则存在高温不稳定，很容易发生分解的问题，所以不建议使用。
在一实施例中，以凝胶骨架单体、柔性添加剂和聚合引发剂的质量之和为100％计，所述凝胶电解质前驱体包括以下组分：
凝胶骨架单体30～80％
柔性添加剂20～60％
聚合引发剂1～10％。在本公开提供的一实施例中，所述凝胶前驱体中，以凝胶骨架单体、柔性添加剂和聚合引发剂的质量之和为100％计，凝胶电解质前驱体中，凝胶骨架单体的质量百分含量为30～80％，例如35％、40％、45％、50％、55％、60％、65％、70％或75％等，柔性添加剂的质量百分含量为20～60％，例如25％、30％、35％、40％、45％、50％或55％等，聚合引发剂的质量百分含量为1～10％，例如2％、3％、5％、7％或9％等。
在一实施例中，所述锂盐的摩尔量与所述凝胶骨架单体的体积之比为0.1～2mol/L，例如0.3mol/L、0.5mol/L、0.8mol/L、1mol/L、1.2mol/L、1.5mol/L或1.8mol/L等。
在一实施例中，所述锂盐的摩尔量与所述凝胶骨架单体的体积之比为0.5～1.5mol/L。
在本公开提供的一实施例中，所述凝胶电解质前驱体中各组分满足上述组成，其有利于后续原位聚合凝胶化，烘烤形成弹性多孔形态；进而有利于其在电池中吸收电解液，形成新的凝胶电解质，保持高的电导率，保证电池的倍率性能；另外，减少了电解液的用量，减少裸电芯外部的游离电解液，提高了电池的安全性能。
在一实施例中，以凝胶骨架单体、柔性添加剂和聚合引发剂的质量之和为100％计，所述凝胶电解质前驱体包括以下组分：
凝胶骨架单体50～65％
柔性添加剂30～45％
聚合引发剂2～5％。
在本公开提供的一实施例中，以凝胶骨架单体、柔性添加剂和聚合引发剂的质量之和为100％计，凝胶电解质前驱体中，凝胶骨架单体的质量百分含量为50％～65％，例如55％、60％或65％等，柔性添加剂的质量百分含量为30～45％，例如33％、35％、38％、40％、42％或44％等，聚合引发剂的摩尔百分含量为2～5％，例如3％、4％等。
本公开在一实施例中提供了一种用于制备凝胶电解质的溶液，所述溶液中包含如一实施例所述的凝胶电解质前驱体和电解液。
在本公开提供的一实施例中，将凝胶电解质前驱体与电解液混合，将其进行凝胶化处理得到凝胶电解质，此处对电解液的配比不作限定，例如，电解液的溶剂可采用碳酸乙烯酯(EC)、碳酸二甲酯(DMC)及碳酸甲乙酯(EMC)的混合液(例如EC:DMC:EMC＝2:4:4)，其中，六氟磷酸锂(LiPF6)含量为1.15mol/L，还含有7wt％氟代碳酸乙烯酯(FEC)。
在一实施例中，所述用于制备凝胶电解质的溶液中凝胶电解质前驱体与电解液的质量之比为0.1:9.9～9.9:0.1，例如1:9、2:8、3:7、5:5、6:4、7:3、8:2或9:1等。
在一实施例中，所述用于制备凝胶电解质的溶液中凝胶电解质前驱体与电解液的质量之比为4:6～6:4。
在一实施例中，所述用于制备凝胶电解质的溶液通过如下方法制备得到，所述方法包括将所述凝胶电解质前驱体与电解液混合，得到所述用于制备凝胶电解质的溶液。
本公开在一实施例中提供了一种凝胶电解质的制备方法，所述方法包括将如一实施例所述的用于制备凝胶电解质的溶液经原位聚合凝胶化，之后烘烤，得到所述凝胶电解质。
在本公开提供的一实施例中，将所述凝胶电解质前驱体与电解液混合，之后原位聚合凝胶化、烘烤后能得到弹性多孔形态的凝胶电解质，其在电池内部能吸收电解液，从而减少电池中游离电解液的存在，提高电池的安全性。
在一实施例中，所述原位聚合凝胶化的温度为70～75℃，例如71℃、72℃、73℃或74℃等。
在一实施例中，所述烘烤为真空烘烤。
在一实施例中，所述真空烘烤的真空度≤0.1kPa；例如0.01kPa、0.03kPa、0.05kPa或0.08kPa等。
在一实施例中，所述烘烤的温度为80～85℃，例如81℃、82℃、83℃或84℃等。
在本公开提供的一实施例中，采用上述凝胶电解质前驱体与电解液混合进行原位聚合凝胶化，之后烘烤挥发除去电解液中的部分溶剂，形成弹性多孔形态凝胶电解质，由其组装半固态电池，添加少量电解液即可。
本公开在一实施例中提供了一种如一实施例所述的方法制备得到的凝胶电解质，所述凝胶电解质为多孔形态。
在一实施例中，所述凝胶电解质为弹性多孔形态。弹性多孔形态的凝胶电解质能吸收电解液，从而减少电池中游离电解液的存在，同时被吸收的电解液与弹性多孔形态凝胶电解质形成新的凝胶电解质，其具有高的电导率，保证电解质高的电导率，保证了电池的倍率性能和电性能，且其减少了电解液的用量，达到了提高电池的安全性的目的。
本公开所述凝胶电解质能适用于电池的正极和/或负极，例如正极和负极均采用本公开所述凝胶电解质、正极或负极中的任意一个采用本公开所述凝胶电 解质，另一个极片采用其他电解质，例如另一个极片采用其他凝胶电解质、不加入凝胶电解质或采用其他类型电解质等。
本公开在一实施例中提供了一种包含凝胶电解质的极片的制备方法，所述制备方法包括：将极片涂覆如一实施例所述的用于制备凝胶电解质的溶液，原位聚合，干燥，得到包含凝胶电解质的极片。
在一实施例中，所述极片包括正极极片和/或负极极片。
此处极片为制作好的正极极片和/或负极极片。
在本公开提供的一实施例中，凝胶电解质前驱体可以应用在任何锂离子电池的正负极材料中，例如，正极活性材料可以为钴酸锂(LCO)、镍酸锂(LNO)、锰酸锂(LMO)、镍钴锰(NCM)或高镍体系；负极活性材料可以为人造石墨、天然石墨、硅氧、硅碳或锂金属等体系。
在一实施例中，所述涂覆的方法包括浸涂。
在一实施例中，所述浸涂的方法包括将所述极片放置在用于制备凝胶电解质的溶液中。
在本公开提供的一实施例中，所述极片浸涂的过程中将极片浸涂在封装有用于制备凝胶电解质的溶液中，在此过程中，极片通过毛细效应充分吸收凝胶电解质前驱体和电解液的混合溶液；放置足够时间后，从铝塑膜中取出极片，擦拭极片表面后完成极片的浸涂；正极极片和负极极片的浸涂方法相同。
在一实施例中，所述极片竖直放置在用于制备凝胶电解质的溶液中。
在一实施例中，浸涂结束后还包括擦拭极片表面。
在一实施例中，所述擦拭采用无尘纸擦拭。
在一实施例中，所述原位聚合的温度为70～75℃，例如70℃、71℃、72℃、73℃、74℃或75℃等。
在本公开提供的一实施例中，所述原位聚合温度控制在上述范围内，其有利于快速凝胶化，当聚合温度过低，凝胶化过程较长，对工程时间及工程能力会有影响；当聚合温度过高，聚合反应过于剧烈，不能够充分完成聚合，可能不会形成凝胶，不能形成很好的凝胶体系，会不利于电池安全性。
此处正极极片的凝胶电解质的原位聚合条件可不同，例如负极极片的原位聚合条件为75℃原位聚合24h，正极极片的原位聚合条件为75℃原位聚合17h。
在一实施例中，所述原位聚合开始前将浸涂后的极片置于铝塑膜中；此处 铝塑膜为干净的铝塑膜。
在一实施例中，所述原位聚合的时间为16-32h，例如17h、19h、21h、24h、28h或30h等。
在一实施例中，所述原位聚合后还包括擦拭极片的极耳。
在一实施例中，所述擦拭极片的极耳采用的溶剂为二甲基亚砜。
浸涂过程中，可能会有前驱体粘到极耳，会影响后面焊接性能，此处原位聚合后采用上述溶剂擦拭极耳，有利于保证后续焊接质量。若能找到方法不粘到极耳，此步骤可以去掉。
在一实施例中，所述原位聚合后还包括干燥。
在一实施例中，所述干燥前将原位聚合后的极片用无尘纸包裹。
正极极片和负极极片的干燥过程不在同一个烘箱中进行，避免交叉污染；且干燥完成后，如果不马上使用，需要使用铝塑膜封装，避免吸收空气中水分。
在一实施例中，所述干燥为真空干燥。
在一实施例中，所述干燥的温度为80～85℃，例如82℃、84℃或85℃等。
此处在上述温度下进行真空干燥，去除电解液中的部分溶剂，从而形成包含弹性多孔状态凝胶电解质的极片，当温度过低时，低沸点组分挥发不完全，不能很好地形成多孔结构，在后期加入电解液后，电解液不能够完全浸润，电池体系电导率较低，倍率性能会受到影响；当温度过高时，会破坏电解质里面锂盐的结构，破坏电解质的弹性，电解质会变脆，电导率降低。
在一实施例中，所述方法包括以下步骤：
(1)将极片竖直放置在封装有用于制备凝胶电解质的溶液的铝塑膜中，竖直放置20～30h，之后取出极片，使用无尘纸擦拭极片表面，完成极片浸涂；
(2)将步骤(1)中浸涂后的极片置于铝塑膜中，将其置于70～75℃下原位聚合24h，之后取出极片，用二甲基亚砜擦拭极耳；
(3)将步骤(2)中原位聚合后的极片用无尘纸包裹，放入烘箱中，80～85℃真空干燥，得到包含凝胶电解质的极片。
本公开在一实施例中提供了一种如一实施例所述的方法制备得到的包含凝胶电解质的极片。
本公开在一实施例中提供了一种半固态电池，所述半固态电池的正极极片或负极极片中的至少一种采用如一实施例所述的包含凝胶电解质的极片。
在一实施例中，所述半固态电池包括软包电池、圆柱电池及方形铝壳电池中的至少一种。
在一实施例中，所述半固态电池为软包电池。
在一实施例中，所述半固态电池的组装方式包括叠片式和/或卷绕式。
在一实施例中，所述半固态电池的制作方法包括将正极极片、负极极片通过卷绕或叠片方式进行组装，之后注液，40～50℃静置，之后化成，得到所述半固态电池；此处对注液和化成的流程不作限定。
附图说明
附图用来提供对本公开技术方案的进一步理解，并且构成说明书的一部分，与本申请的实施例一起用于解释本公开的技术方案，并不构成对本公开技术方案的限制。
图1是本公开一个实施例中正极极片浸涂过程的工艺流程；
图2是本公开一个实施例中正极极片浸涂后原位聚合凝胶化的工艺流程图；
图3是本公开一个实施例中包含凝胶电解质的正极极片表面SEM+EDX图片；
图4是本公开一个实施例中包含凝胶电解质的正极极片表面的SEM图片，其中，方框区域记为区域A，即下部区域；
图5是本公开一个实施例中包含凝胶电解质的正极极片表面的SEM图片，其中，方框区域记为区域B，即上部区域；
图6是本公开对比例1中液体NCM-Cr电池的针刺安全性测试的光学图片；
图7是本公开一个实施例中半固态电池(PVCA凝胶态NCM-Gr电池)的针刺安全性测试的光学图片。
具体实施例
下面结合附图并通过具体实施方式来进一步说明本公开的技术方案。本领域技术人员应该明了，所述实施例仅仅是帮助理解本公开，不应视为对本公开的具体限制。
本公开在一实施例中提供一种包含凝胶电解质的正极极片的制备方法，该方法的制备流程示意图如图1及图2所示，包括以下步骤：
(a)配制凝胶电解质前驱体和电解液；
(b)将凝胶电解质前驱体和电解液混合，得到混合液，将混合液置于铝塑膜中；
(c)将正极极片竖直置于步骤(b)的铝塑膜中进行正极极片浸涂；
(d)对浸涂后的正极极片进行表面处理，即使用无尘纸擦拭正极极片表面；
(e)将步骤(d)中的正极极片重新置于新的铝塑膜中，进行原位聚合(例如75℃原位聚合24h)；
(f)将原位聚合后的正极极片的极耳进行擦拭，例如先采用DMSO擦拭极耳，再使用干燥无尘纸擦拭极耳；
(g)将步骤(f)的正极极片进行真空干燥，得到包含有凝胶电解质的正极极片；所述凝胶电解质为弹性多孔状态。
以下为本公开典型但非限制性实施例：
实施例1
本实施例中凝胶电解质前驱体中包含以下组成：凝胶骨架单体、柔性添加剂、聚合引发剂及锂盐；
其中，凝胶骨架单体为丙烯腈单体；
柔性添加剂为丁二腈；
聚合引发剂为偶氮二异丁腈；
锂盐为双三氟甲烷磺酰亚胺锂。
以凝胶骨架单体、柔性添加剂和聚合引发剂的质量之和为100％计，所述凝胶电解质前驱体包括以下组分：
凝胶骨架单体58％
柔性添加剂38％
聚合引发剂4％；
所述锂盐的摩尔量与所述凝胶骨架单体的体积之比为1mol/L；
电解液的组成：溶剂为体积比EC:DMC:EMC＝2:4:4，LiPF6含量1.15mol/L，还含有7％FEC；
凝胶电解质前驱体与电解液混合的质量比为1:1；
正极极片：集流体为12μm铝箔，正极活性材料使用NCM622，粘结剂为 PVDF 5130，导电剂SP；
负极极片：集流体为8μm铜箔，负极活性材料使用人造石墨和硬碳混合物，导电剂为SP，粘结剂为CMC&SBR；
包含有凝胶电解质的负极极片的制备方法：
(1)将制备好的负极极片竖直放置在封装有用于制备凝胶电解质的溶液的铝塑膜中，竖直放置24h，之后取出极片，使用无尘纸擦拭极片表面，完成负极极片浸涂；
(2)将步骤(1)中浸涂后的负极极片置于新的铝塑膜中，将其置于75℃下原位聚合24h，之后取出极片，用二甲基亚砜擦拭极耳；
(3)将步骤(2)中原位聚合后的极片用无尘纸包裹，放入烘箱中，85℃真空干燥24h，得到包含凝胶电解质的极片。
包含有凝胶电解质的正极极片的制备方法与负极极片的区别仅在于，原位聚合条件替换为75℃原位聚合17h；且采用不同的烘箱避免交叉污染，其他条件均相同。
组装半固态电池：
本实施例采用叠片的方式制备半固态电池，叠片后经注液(1.5g/Ah)、45℃静置，化成，得到半固态电池，记为聚丙烯腈(PAN-SN)凝胶态NCM-Gr电池。
对实施例1中得到的包含凝胶电解质的负极极片的凝胶形成的均匀性进行测试，测试方法采用SEM+EDX；使用LiTFSI中的S元素进行标定，其电镜图如图3所示，由SEM+EDX图片中可以看出，S元素分布均匀，极片中凝胶形成自上而下的均匀分布；使用元素百分比标定，如图4(下部区域)和图5(上部区域)所示，同一极片，上下部位置S元素含量分别为上部：4.1％，下部：4.01％；在4±0.2％的范围内；凝胶形成是非常均匀的。
图4中下部区域内元素分布表如表1所示：
表1
Figure PCTCN2021082142-appb-000001
Figure PCTCN2021082142-appb-000002
图5中上部区域内元素分布表如下表2所示：
表2
元素 原子数 净值 质量(％) 归一化质量(％) 原子
C 6 193057 87.54 84.54 89.57
N 7 579 2.16 1.5 1.36
O 8 4545 4.16 4.15 3.30
F 9 3019 2.13 1.6 1.07
S 16 8358 4.01 3.98 2.79
    总计： 100.00 100.00 100.00
实施例2
本实施例与实施例1的区别在于，以凝胶骨架单体、柔性添加剂和聚合引发剂的质量之和为100％计，所述凝胶电解质前驱体包括以下组分：
凝胶骨架单体75％
柔性添加剂20％
聚合引发剂5％；
所述锂盐的摩尔量与所述凝胶骨架单体的体积之比为2mol/L；
其他参数和条件与实施例1中完全相同。
实施例3
本实施例与实施例1的区别在于，以凝胶骨架单体、柔性添加剂和聚合引发剂的质量之和为100％计，所述凝胶电解质前驱体包括以下组分：
凝胶骨架单体30％
柔性添加剂60％
聚合引发剂10％；
所述锂盐的摩尔量与所述凝胶骨架单体的体积之比为0.1mol/L；
其他参数和条件与实施例1中完全相同。
实施例4
本实施例与实施例1的区别在于，以凝胶骨架单体、柔性添加剂和聚合引发剂的质量之和为100％计，所述凝胶电解质前驱体包括以下组分：
凝胶骨架单体65％
柔性添加剂30％
聚合引发剂5％；
所述锂盐的摩尔量与所述凝胶骨架单体的体积之比为1.5mol/L；
其他参数和条件与实施例1中完全相同。
实施例5
本实施例与实施例1的区别在于，凝胶电解质前驱体与电解液的质量之比由1:1替换为9:1，其他参数和条件与实施例1中相比完全相同。
实施例6
本实施例与实施例1的区别在于，凝胶电解质前驱体与电解液的质量之比由1:1替换为1:9，其他参数和条件与实施例1中相比完全相同。
实施例7
本实施例与实施例1的区别在于，将柔性添加剂等质量的替换为离子液体，离子液体的组成为1-丁基-1-甲基哌啶双(三氟甲磺酰基)亚胺盐(PP14TFSI)，其他参数和条件与实施例1中完全相同。
实施例8
本实施例与实施例1的区别在于，将前驱体中锂盐等摩尔量的替换为高氯酸锂，其他参数和条件与实施例1中完全相同。
实施例9
本实施例与实施例1的区别在于，将前驱体中锂盐等摩尔量的替换为四氟硼酸锂，其他参数和条件与实施例1中完全相同。
实施例10
本实施例与实施例1的区别仅在于，包含有凝胶电解质的负极极片和正极极片的制备过程中采用涂布的方法，即不采用浸涂；将凝胶电解质前驱体和电解液的混合溶液涂覆在极片的表面，之后原位聚合，烘烤，得到包含有凝胶电解质的负极极片和正极极片，其他参数和条件与实施例1中完全相同。
本实施例中采用涂布方法将凝胶电解质前驱体涂布在正极极片表面，原位聚合后使用SEM+EDX元素分析结果显示，极片表面凝胶电解质含量很高，极片底部(靠近集流体侧)电解质含量≈0％；浸涂后极片上部和底部含量很不均匀，没有达到完全浸润的目的。
对比例1
本对比例与实施例1的区别仅在于，正极极片和负极极片上不包含凝胶电解质，直接将制作好的正极极片和负极极片进行叠片，之后注液(2.65g/Ah)，静置，化成，得到液态电池，记为液态NCM-Gr(正极三元材料、负极石墨和硬碳)电池。
实施例1与对比例1中电池倍率性能测试结果如表3所示：
表3
Figure PCTCN2021082142-appb-000003
由表3可以看出，本公开所述PAN-SN凝胶态NCM-Gr电池的倍率性能与液态电池相近。
实施例1和对比例1中电池充放电容量及首效的测试结果如表4所示；
表4
Figure PCTCN2021082142-appb-000004
由表4可以看出，在同一体系下，使用PAN-SN电解质电池在充电容量，放电容量，首次效率方面跟传统NCM-Gr电池差异很小，说明本公开凝胶材料对电池没有副作用。
对比例1和实施例1中电池针刺安全性测试的光学图片分别如图6和图7所示，实施例1中半固态电池能通过针刺测试，而对比例1中针刺发生起火；由此说明采用本公开所述凝胶电解质前驱体得到的半固态电池具有更高的安全性。
对比例2
本对比例与实施例1的区别在于，凝胶电解质前驱体中不含柔性添加剂，其他参数和条件与实施例1中完全相同。
对比例3
本对比例与实施例1的区别在于，凝胶电解质前驱体中不含锂盐，其他参数和条件与实施例1中完全相同。
对比例4
本对比例与实施例1的区别在于，将实施例1中的锂盐替换为LiPF6，其他参数和条件与实施例1中完全相同。
本对比例使用LiPF6为凝胶电解质前驱体的锂盐，经过75℃凝胶化后不能够完全形成凝胶，材料部分仍是液体，且颜色变成黑褐色。
性能测试：
对实施例和对比例中得到的电池进行倍率性能、首效、循环性能和安全性(针刺测试)的测试，测试结果如表5所示：
其中，倍率性能测试条件：
a)恒流恒压充电：0.33C CC 4h to 4.25V，CV to 0.05C；
b)静置5min；
c)恒流放电：0.33C DC to 2.5V；
d)静置5min；
e)恒流恒压充电：0.33C CC 4h to 4.25V，CV to 0.05C；
f)静置5min；
g)恒流放电：1C DC to 2.5V。
测试得到1C/0.33C的倍率性能，其他条件下1C/0.5C、1C/1C、1C/2C的倍率性能测试参数参照上述条件。
首效测试条件：环境温度为25℃；
a)恒流恒压充电：0.05C CC 22h to 4.25V，CV to 0.01C；
b)静置10min；
c)恒流放电：0.05C DC to 2.5V。
循环性能测试条件：测试温度为25℃；
a)恒流恒压充电：1C CC to 4.25V，CV to 0.05C；
b)静置5min；c)恒流放电：1C DC to 2.5V；
d)循环步骤a)-步骤c)100次。
安全性(针刺测试)条件：
参照GBT31485-2015电动汽车用动力蓄电池安全要求及试验方法，步骤如下：
a)单体电池充电；
b)用φ6.5mm的耐高温钢针(针尖的圆锥角度为50°，针的表面光洁、无锈蚀、氧化层及油污)，以25mm/s的速度，从垂直于蓄电池极板的方向贯穿，贯穿位置靠近所刺面的几何中心，钢针停留在电池中；
c)观察1h。
上述测试结果如表5所示；
表5
Figure PCTCN2021082142-appb-000005
Figure PCTCN2021082142-appb-000006
由上表5可以看出，本公开所述凝胶电解质前驱体与电解液混合原位聚合凝化得到的凝胶电解质，由其组装得到的电池的安全性明显改善，且所得半固态电池的电性能可达到与液体电池相近，取得了在保持高的电性能的同时，提升了电池安全性的效果。
对比实施例1-4可以看出，本公开所述凝胶电解质前驱体中各组分的含量会影响半固态电池的性能，各组分的含量满足一下条件时，所得半固态电池的电性能和安全性能改善更为明显：以凝胶骨架单体、柔性添加剂和聚合引发剂的质量之和为100％计，所述凝胶电解质前驱体包括以下组分：凝胶骨架单体的质量百分含量为50～65％，柔性添加剂的质量百分含量为30～45％，聚合引发剂的质量百分含量为2～5％。
对比实施例1、5-6可以看出，凝胶电解质前驱体与电解液的质量比为0.1:9.9～9.9:1时，其均能得到较高的电化学性能及安全性，质量比为4:6～6:4时改善效果更佳，质量比为1:1时改善效果最佳。
对比实施例1、7可以看出，离子液体作为柔性添加剂加入，其得到的凝胶电解质前驱体与电解液混合得到的半固态电池的性能与液体电池相近，但离子液体存在成本较高的问题。
对比实施例1、8、9可以看出，本公开凝胶电解质前驱体中锂盐选用双三氟甲烷磺酰亚胺锂时半固态电池的性能优于采用高氯酸锂或硼酸锂。
对比实施例1、10可以看出，本公开所述方法采用浸涂，其更有利于提高电池的电化学性能及安全性。
对比实施例1和对比例1可以看出，本公开所述凝胶电解质前驱体得到的 凝胶电解质组装的电池可达到与液体电池相近的电性能，且具有更高的安全性。
对比例2中不含柔性添加剂，不能够形成凝胶，缺少柔性添加剂，骨架单体聚合会造成材料结晶度升高，导致材料粉化沉淀；对比例3中不含锂盐，可以形成凝胶，但是凝胶体系电导率会降低，性能会较加入锂盐的变差，且安全性也变差。
对比实施例1及对比例4可以看出，前驱体中锂盐采用六氟磷酸锂，无法完全形成凝胶，且颜色变黑，安全性差。

Claims (42)

  1. 一种凝胶电解质前驱体，所述凝胶电解质前驱体包括凝胶骨架单体、柔性添加剂、聚合引发剂及锂盐，其中，所述凝胶骨架单体包括丙烯腈类单体。
  2. 如权利要求1所述的凝胶电解质前驱体，其中，所述丙烯腈类单体包括丙烯腈、烯丙基腈、2-溴丙烯腈、1-环己烯乙腈、3,3-二苯基丙烯腈、3-环己烯-1-腈、1-环戊烯乙腈、2-乙氧基丙烯腈、1,2-二氰基环丁烯、环乙烯基-1,2-二腈、二氨基马来腈、3,3-二甲氧基-2-丙烯腈、乙氧基亚甲基丙二腈、2-叔丁基顺丁烯二腈、2,2,3,4,4-五氟-3-丁烯腈、1-氰基-2-丙烯基乙酸酯及苄烯丙二腈中的至少一种。
  3. 如权利要求1所述的凝胶电解质前驱体，其中，所述凝胶骨架单体为丙烯腈。
  4. 如权利要求1-3任一项所述的凝胶电解质前驱体，其中，所述柔性添加剂选自丁二腈和/或离子液体。
  5. 如权利要求4所述的凝胶电解质前驱体，其中，所述离子液体包括1-甲基-1-丙基哌啶双三氟甲基磺酰亚胺盐、1-丁基-1-甲基哌啶双(三氟甲磺酰基)亚胺盐、1-丁基-1-甲基吡咯烷双(三氟甲磺酰)亚胺盐、1-甲基-1-丙基吡咯烷鎓双(氟磺酰)亚胺、1-丙基-1-甲基吡咯烷双三氟甲磺酰亚胺盐、1-乙基-3-甲基咪唑双三氟甲磺酰亚胺盐及1-乙基-3-甲基咪唑四氟硼酸盐中的至少一种。
  6. 如权利要求1-3任一项所述的凝胶电解质前驱体，其中，所述聚合引发剂选自偶氮二异丁腈和/或偶氮二异庚腈。
  7. 如权利要求6所述的凝胶电解质前驱体，其中，所述聚合引发剂为偶氮二异丁腈。
  8. 如权利要求1-7任一项所述的凝胶电解质前驱体，其中，所述锂盐选自高氯酸锂、双三氟甲烷磺酰亚胺锂、双氟磺酰亚胺锂、双乙二酸硼酸锂及四氟硼酸锂中的至少一种。
  9. 如权利要求8所述的凝胶电解质前驱体，其中，所述锂盐为双三氟甲烷磺酰亚胺锂。
  10. 如权利要求1-9任一项所述的凝胶电解质前驱体，其中，以凝胶骨架单体、柔性添加剂和聚合引发剂的质量之和为100％计，所述凝胶电解质前驱体包括以下组分：
    凝胶骨架单体  30～80％
    柔性添加剂   20～60％
    聚合引发剂   1～10％。
  11. 如权利要求10所述的凝胶电解质前驱体，其中，所述锂盐的摩尔量与所述凝胶骨架单体的体积之比为0.1～2mol/L。
  12. 一种用于制备凝胶电解质的溶液，所述溶液中包含如权利要求1-11任一项所述的凝胶电解质前驱体和电解液。
  13. 如权利要求12所述的用于制备凝胶电解质的溶液，其中，所述用于制备凝胶电解质的溶液中，凝胶电解质前驱体与电解液的质量之比为0.1:9.9～9.9:0.1。
  14. 如权利要求13所述的用于制备凝胶电解质的溶液，其中，所述用于制备凝胶电解质的溶液中，凝胶电解质前驱体与电解液的质量之比为4:6～6:4。
  15. 如权利要求12-14任一项所述的用于制备凝胶电解质的溶液，其中，所述用于制备凝胶电解质的溶液通过如下方法制备得到，所述方法包括将所述凝胶电解质前驱体与电解液混合，得到所述用于制备凝胶电解质的溶液。
  16. 一种凝胶电解质的制备方法，所述方法包括将如权利要求12-15任一项所述的用于制备凝胶电解质的溶液经原位聚合凝胶化，之后烘烤，得到所述凝胶电解质。
  17. 如权利要求16所述的凝胶电解质的制备方法，其中，所述原位聚合凝胶化的温度为70～75℃。
  18. 如权利要求16或17所述的凝胶电解质的制备方法，其中，所述烘烤为真空烘烤。
  19. 如权利要求18所述的凝胶电解质的制备方法，其中，所述真空烘烤的真空度≤0.1kPa。
  20. 如权利要求16-19任一项所述的凝胶电解质的制备方法，其中，所述烘烤的温度为80～85℃。
  21. 一种如权利要求16-20任一项所述的方法制备得到的凝胶电解质，所述凝胶电解质为多孔形态。
  22. 如权利要求21所述的凝胶电解质，其中，所述凝胶电解质为弹性多孔形态。
  23. 一种包含凝胶电解质的极片的制备方法，所述制备方法包括：将极片 涂覆如权利要求12-15任一项所述的用于制备凝胶电解质的溶液，原位聚合，干燥，得到包含凝胶电解质的极片。
  24. 如权利要求23所述的包含凝胶电解质的极片的制备方法，其中，所述极片包括正极极片和/或负极极片。
  25. 如权利要求23或24所述的包含凝胶电解质的极片的制备方法，其中，所述涂覆的方法包括浸涂。
  26. 如权利要求25所述的包含凝胶电解质的极片的制备方法，其中，所述浸涂的方法包括将所述极片放置在用于制备凝胶电解质的溶液中。
  27. 如权利要求26所述的包含凝胶电解质的极片的制备方法，其中，所述极片竖直放置在用于制备凝胶电解质的溶液中。
  28. 如权利要求25-27任一项所述的包含凝胶电解质的极片的制备方法，其中，浸涂结束后还包括擦拭极片表面。
  29. 如权利要求28所述的包含凝胶电解质的极片的制备方法，其中，所述擦拭采用无尘纸擦拭。
  30. 如权利要求23-29任一项所述的包含凝胶电解质的极片的制备方法，其中，所述原位聚合的温度为70～75℃。
  31. 如权利要求23-30任一项所述的包含凝胶电解质的极片的制备方法，其中，所述原位聚合的时间为16-32h。
  32. 如权利要求23-31任一项所述的包含凝胶电解质的极片的制备方法，其中，所述原位聚合后还包括擦拭极片的极耳。
  33. 如权利要求32所述的包含凝胶电解质的极片的制备方法，其中，所述擦拭极片的极耳采用的溶剂为二甲基亚砜。
  34. 如权利要求23-33任一项所述的包含凝胶电解质的极片的制备方法，其中，所述干燥为真空干燥。
  35. 如权利要求23-34任一项所述的包含凝胶电解质的极片的制备方法，其中，所述干燥的温度为80～85℃。
  36. 如权利要求23-35任一项所述的包含凝胶电解质的极片的制备方法，其中，所述方法包括以下步骤：
    (1)将极片竖直放置在封装有用于制备凝胶电解质的溶液的铝塑膜中，竖直放置20～30h，之后取出极片，使用无尘纸擦拭极片表面，完成极片浸涂；
    (2)将步骤(1)中浸涂后的极片置于铝塑膜中，将其置于70～75℃下原位聚合24h，之后取出极片，用二甲基亚砜擦拭极耳；
    (3)将步骤(2)中原位聚合后的极片用无尘纸包裹，放入烘箱中，80～85℃真空干燥，得到包含凝胶电解质的极片。
  37. 一种如权利要求23-36任一项所述的方法制备得到的包含凝胶电解质的极片。
  38. 如权利要求37所述的包含凝胶电解质的极片，其中，所述包含凝胶电解质的极片上的凝胶电解质为多孔形态。
  39. 如权利要求38所述的包含凝胶电解质的极片，其中，所述包含凝胶电解质的极片上的凝胶电解质为弹性多孔形态。
  40. 一种半固态电池，所述半固态电池的正极极片或负极极片中的至少一种采用如权利要求37-39任一项所述的包含凝胶电解质的极片。
  41. 如权利要求40所述的半固态电池，其中，所述半固态电池包括软包电池、圆柱电池及方形铝壳电池中的至少一种。
  42. 如权利要求41所述的半固态电池，其中，所述半固态电池为软包电池。
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