WO2024066507A1 - Bab-type block copolymer, preparation method, binder, positive pole piece, secondary battery, and electrical apparatus - Google Patents

Bab-type block copolymer, preparation method, binder, positive pole piece, secondary battery, and electrical apparatus Download PDF

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Publication number
WO2024066507A1
WO2024066507A1 PCT/CN2023/101439 CN2023101439W WO2024066507A1 WO 2024066507 A1 WO2024066507 A1 WO 2024066507A1 CN 2023101439 W CN2023101439 W CN 2023101439W WO 2024066507 A1 WO2024066507 A1 WO 2024066507A1
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Prior art keywords
poly
acrylic acid
block
acrylate
polyvinylidene fluoride
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PCT/CN2023/101439
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French (fr)
Chinese (zh)
Inventor
曾子鹏
李�诚
刘会会
孙成栋
王景明
Original Assignee
宁德时代新能源科技股份有限公司
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Priority claimed from CN202211206844.2A external-priority patent/CN115286805A/en
Priority claimed from PCT/CN2022/128035 external-priority patent/WO2024087112A1/en
Application filed by 宁德时代新能源科技股份有限公司 filed Critical 宁德时代新能源科技股份有限公司
Publication of WO2024066507A1 publication Critical patent/WO2024066507A1/en

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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G81/00—Macromolecular compounds obtained by interreacting polymers in the absence of monomers, e.g. block polymers
    • C08G81/02—Macromolecular compounds obtained by interreacting polymers in the absence of monomers, e.g. block polymers at least one of the polymers being obtained by reactions involving only carbon-to-carbon unsaturated bonds
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • 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
    • 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
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers

Definitions

  • the present application relates to the technical field of secondary batteries, and in particular to a BAB-type block copolymer, a preparation method, a binder, a positive electrode sheet, a secondary battery and an electrical device.
  • secondary batteries have been widely used in energy storage power systems such as hydropower, thermal, wind and solar power stations, as well as in power tools, electric bicycles, electric motorcycles, electric vehicles, military equipment, aerospace and other fields.
  • Binders are commonly used materials in secondary batteries and are widely used in battery pole pieces, separators, packaging, etc.
  • traditional binders have high production costs, insufficient production capacity, great environmental hazards, and are prone to gelation during the preparation process, resulting in poor slurry stability and high processing costs.
  • the pole pieces prepared with them have poor flexibility, low adhesion, high resistance, and low yield.
  • the battery has a high DC impedance growth rate, low cycle capacity retention rate, and unstable performance, which makes it difficult to meet the market's requirements for battery cost and performance. Therefore, existing binders still need to be improved.
  • the present application is made in view of the above-mentioned problems, and its purpose is to provide a BAB
  • the binder prepared with the BAB type block copolymer can effectively slow down the gelation phenomenon of the slurry, improve the stability of the slurry, improve the flexibility of the pole piece, improve the bonding force, reduce the membrane resistance, reduce the DC impedance growth rate of the battery, and/or improve the cycle capacity retention rate of the battery.
  • the first aspect of the present application provides a BAB type block copolymer, characterized in that it comprises an A-block and a B-block, wherein the A-block contains a structural unit derived from a monomer represented by formula I, and the B-block contains a structural unit derived from a monomer represented by formula II;
  • the A-block contains structural units derived from the monomers of formula II
  • the B-block contains structural units derived from the monomers of formula I
  • R 1 , R 2 , and R 3 are each independently selected from one or more of hydrogen, fluorine, and C 1-3 alkyl containing at least one fluorine atom; and R 4 , R 5 , and R 6 are each independently selected from hydrogen, and substituted or unsubstituted C 1-5 alkyl.
  • the binder prepared with the BAB type block copolymer can maximize the weight average molecular weight of the fluorine-containing block and the non-fluorine block, give full play to the respective advantages of the fluorine-containing binder and the non-fluorine binder, and achieve the role of complementary advantages.
  • the binder can effectively slow down the gelation phenomenon of the slurry, improve the stability of the slurry, improve the flexibility of the pole piece, improve the bonding force, reduce the membrane resistance, reduce the DC impedance growth rate of the battery, and/or improve the cycle capacity retention rate of the battery.
  • the B-block further comprises a structural unit derived from a monomer of formula III; or the A-block further comprises a structural unit derived from a monomer of formula III,
  • R 7 , R 8 and R 9 are each independently selected from hydrogen, substituted or unsubstituted C 1-5 alkyl, and R 10 is selected from one of ester group, cyano group and amide group.
  • the molar content of the structural unit derived from the monomer represented by formula I is 30%-70%, and optionally 40%-60%.
  • Controlling the molar content of the structural unit derived from the monomer represented by Formula I within a suitable range can effectively slow down the gelation of the slurry, improve the stability of the slurry, increase the flexibility of the pole piece, reduce the membrane resistance, and improve the cycle capacity retention rate of the battery.
  • the weight average molecular weight of the block copolymer is 400,000-2,000,000, the weight average molecular weight of the block copolymer can be selected to be 1.2 million-2,000,000, and the weight average molecular weight of the block copolymer can be selected to be 1.2 million-1.5 million.
  • Controlling the weight-average molecular weight of the block copolymer within an appropriate range can effectively slow down the gelation of the slurry, improve the stability of the slurry, increase the flexibility of the pole piece, increase the bonding force, reduce the membrane resistance, reduce the DC impedance growth rate of the battery, and improve the cycle capacity retention rate of the battery.
  • the weight average molecular weight of the A-block is 200,000 to 1,050,000.
  • Controlling the weight average molecular weight of the A-block in the block copolymer within a suitable range can effectively slow down the gelation of the slurry, improve the stability of the slurry, increase the flexibility of the pole piece, reduce the membrane resistance, and improve the cycle capacity retention rate of the battery.
  • the weight average molecular weight of each B-block is 100,000 to 500,000.
  • Controlling the weight average molecular weight of each B-block in the block copolymer within a suitable range can improve the bonding force and increase the cycle capacity retention rate of the battery.
  • the monomer represented by formula I is selected from one or more of vinylidene fluoride, tetrafluoroethylene, vinyl fluoride, and hexafluoropropylene.
  • the bonding force can be improved, and the cycle capacity retention rate of the battery can be improved.
  • the monomer represented by formula II is selected from acrylic acid, methacrylic acid, One or more of acrylic acid, ethacrylic acid.
  • the monomer represented by formula III is selected from one or more of acrylamide, acrylate, and acrylonitrile.
  • the gelation phenomenon of the slurry can be effectively slowed down, the stability of the slurry can be improved, the flexibility of the electrode can be improved, the membrane resistance can be reduced, and the cycle capacity retention rate of the battery can be improved.
  • the above raw materials are simple and easy to obtain, and compared with traditional adhesives, they can significantly reduce production costs and increase output.
  • the block copolymer is a polyacrylic acid-polyvinylidene fluoride-polyacrylic acid triblock copolymer, a polyacrylic acid-polyvinyl fluoride-polyacrylic acid triblock copolymer, a polyacrylic acid-polytetrafluoroethylene-polyacrylic acid triblock copolymer, a poly(acrylic acid-acrylate)-polyvinylidene fluoride-poly(acrylic acid-acrylate) triblock copolymer, a poly(acrylic acid-acrylate)-polyvinyl fluoride-poly(acrylic acid-acrylate) triblock copolymer, a poly(acrylic acid-acrylate)-polyvinyl fluoride-poly(acrylic acid-acrylate) triblock copolymer, a poly(acrylic acid-acrylate)-polyvinyl fluoride-poly(acrylic acid-acrylate) triblock copolymer, a poly(acrylic
  • the second aspect of the present application also provides a method for preparing a BAB type block copolymer, characterized in that it comprises the following steps:
  • Preparing the A-block polymerizing at least one monomer represented by formula I to prepare the A-block;
  • the A-block is prepared by polymerizing monomer units, wherein the monomer units include at least one monomer represented by formula II,
  • R 1 , R 2 , and R 3 are each independently selected from one or more of hydrogen, fluorine, and a C 1-3 alkyl group containing at least one fluorine atom; and R 4 , R 5 , and R 6 are each independently selected from one or more of hydrogen, substituted or unsubstituted Substituted C 1-5 alkyl;
  • B-block polymerizing monomer units to prepare B-block, wherein the monomer units include at least one monomer represented by formula II,
  • At least one monomer of formula I is polymerized to prepare a B-block
  • Preparation of a BAB type block copolymer The A-block and the B-block are joined to prepare a BAB type block copolymer, wherein the A-block and the B-block contain different structural units.
  • this preparation method can maximize the weight average molecular weight of the fluorine-containing block and the non-fluorine block, give full play to the advantages of the fluorine-containing binder and the non-fluorine binder, and achieve the role of complementary advantages.
  • the binder of the BAB-type triblock copolymer prepared by this method can effectively slow down the gelation phenomenon of the slurry, improve the stability of the slurry, improve the flexibility of the pole piece, improve the bonding force, reduce the membrane resistance, reduce the DC impedance growth rate of the battery, and/or improve the cycle capacity retention rate of the battery.
  • the monomer unit further comprises at least one monomer represented by formula III,
  • R 7 , R 8 and R 9 are each independently selected from hydrogen, substituted or unsubstituted C 1-5 alkyl, and R 10 is selected from one of ester group, cyano group and amide group.
  • the method for preparing the B-block comprises:
  • At least one monomer or monomer unit represented by formula I, a chain transfer agent and a first initiator are subjected to reversible addition-fragmentation chain transfer polymerization at a reaction temperature of 60-80° C. for 4.5-7 hours to obtain the B-block having an alkynyl group or an azide group as an end group.
  • controllable polymerization can be achieved, and the molecular weight distribution of the product is relatively narrow.
  • the method for preparing the A-block comprises:
  • At least one monomer or monomer unit of Formula I and a second initiator are polymerized at a reaction temperature of 80-95° C. for 2.5-5 hours, and the end groups of the products are substituted to prepare
  • the A-block has an azide group or an alkynyl group as a terminal group at both ends.
  • the method for preparing a BAB type block copolymer comprises:
  • the A-block having an azide group or an alkynyl group as an end group at both ends is mixed with the B-block having an alkynyl group or an azide group as an end group at the end, and a click reaction is performed to prepare a BAB type block copolymer, wherein the end groups of the A-block and the B-block are different.
  • the above preparation method has the advantages of high efficiency, stability and high specificity, and improves the yield rate of the product.
  • the chain transfer agent is a RAFT chain transfer agent containing a terminal alkynyl or azide group.
  • the first initiator is an azo initiator, selected from one or both of azobisisobutyronitrile and azobisisoheptanenitrile.
  • the second initiator is a symmetrical bifunctional initiator selected from 4-(chloromethyl)benzoyl peroxide.
  • the third aspect of the present application provides the use of the BAB type block copolymer in any embodiment or the BAB type block copolymer prepared by the preparation method in any embodiment in a secondary battery.
  • the fourth aspect of the present application provides a positive electrode plate, including a positive electrode current collector and a positive electrode film layer arranged on at least one surface of the positive electrode current collector, the positive electrode film layer includes a positive electrode active material, a conductive agent and a binder, and the binder is a BAB type block copolymer in any embodiment or a BAB type block copolymer prepared by the preparation method in any embodiment.
  • the positive electrode sheet has excellent flexibility and adhesion, as well as low membrane resistance.
  • the mass fraction of the binder is 0.1%-3%, and the mass fraction of the binder can be optionally 1%-3%, based on the total mass of the positive electrode active material.
  • Controlling the mass fraction of the binder within a reasonable range can significantly slow down the gelation of the slurry, improve the stability of the slurry, increase the flexibility of the electrode, and increase the cycle capacity of the battery. Holding rate.
  • the bonding force per unit length between the positive electrode film layer and the positive electrode current collector is not less than 8 N/m, and optionally, the bonding force per unit length between the positive electrode film layer and the positive electrode current collector is not less than 10 N/m.
  • the positive electrode film layer of the pole piece has high bonding strength with the positive electrode current collector. During use, the positive electrode film layer is not easy to fall off from the positive electrode current collector, which helps to improve the cycle performance and safety of the battery.
  • the positive electrode plate after the positive electrode plate has been subjected to no less than three bending tests, the positive electrode plate becomes light-transmissive.
  • the electrode has excellent flexibility and is not prone to cracking during the production process, which helps to improve the yield rate.
  • the diaphragm resistance of the positive electrode plate is ⁇ 0.52 ⁇ , and optionally the diaphragm resistance of the positive electrode plate is ⁇ 0.46 ⁇ .
  • a secondary battery comprising an electrode assembly and an electrolyte, wherein the electrode assembly comprises a separator, a negative electrode plate and the positive electrode plate of the fourth aspect of the present application.
  • the secondary battery comprises at least one of a lithium ion battery, a sodium ion battery, a magnesium ion battery and a potassium ion battery.
  • an electrical device comprising the secondary battery of the fifth aspect of the present application.
  • FIG1 is a schematic diagram of the preparation of a BAB type block copolymer according to an embodiment of the present application.
  • FIG2 is a schematic diagram of a secondary battery according to an embodiment of the present application.
  • FIG3 is an exploded view of the secondary battery of one embodiment of the present application shown in FIG2 ;
  • FIG4 is a schematic diagram of a battery module according to an embodiment of the present application.
  • FIG5 is a schematic diagram of a battery pack according to an embodiment of the present application.
  • FIG6 is an exploded view of the battery pack according to an embodiment of the present application shown in FIG5 ;
  • FIG. 7 is a diagram of an electric device in which a secondary battery is used as a power source in one embodiment of the present application. intention.
  • range disclosed in the present application is defined in the form of a lower limit and an upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of a particular range.
  • the range defined in this way can be inclusive or exclusive of end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range. For example, if a range of 60-120 and 80-110 is listed for a specific parameter, it is understood that the range of 60-110 and 80-120 is also expected.
  • the numerical range "a-b" represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers.
  • the numerical range "0-5" represents that all real numbers between "0-5" have been fully listed herein, and "0-5" is just the abbreviation of these numerical combinations.
  • a parameter is expressed as an integer ⁇ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.
  • the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially.
  • the method may further include step (c), which means that step (c) may be added to the method in any order.
  • the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.
  • the “include” and “comprising” mentioned in this application represent open-ended or closed-ended expressions.
  • the “include” and “comprising” may represent that other components not listed may also be included or only the listed components may be included or only the listed components may be included.
  • the term "or” is inclusive.
  • the phrase “A or B” means “A, B, or both A and B”. More specifically, any of the following conditions satisfies the condition "A or B”: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).
  • binders have high production costs, insufficient production capacity, and great environmental hazards. They are prone to gelation during the preparation process, resulting in poor slurry stability and high processing costs.
  • the pole pieces prepared with them have poor flexibility, low bonding force, high resistance, and low yield.
  • the battery has a high DC impedance growth rate, low cycle capacity retention rate, and unstable performance, making it difficult to meet the market's requirements for battery cost and performance. Therefore, existing binders still need to be improved.
  • a BAB type block copolymer comprising an A-block and a B-block, wherein the A-block contains a structural unit derived from a monomer represented by formula I, and the B-block contains a structural unit derived from a monomer represented by formula II;
  • the A-block contains structural units derived from the monomers of formula II
  • the B-block contains structural units derived from the monomers of formula I
  • R 1 , R 2 , and R 3 are each independently selected from one or more of hydrogen, fluorine, and C 1-3 alkyl containing at least one fluorine atom; and R 4 , R 5 , and R 6 are each independently selected from hydrogen, and substituted or unsubstituted C 1-5 alkyl.
  • the B-block further comprises a structural unit derived from a monomer of formula III,
  • R 7 , R 8 and R 9 are each independently selected from hydrogen, substituted or unsubstituted C 1-5 alkyl, and R 10 is selected from one of ester group, cyano group and amide group.
  • binder refers to a chemical compound, polymer or mixture that forms a colloidal solution or colloidal dispersion in a dispersion medium.
  • block copolymer refers to a special type of polymer made by linking two or more polymer segments with different properties. Block polymers with specific structures will exhibit different properties from simple linear polymers, many random copolymers, and even mixtures of homopolymers. Common types include AB and BAB types, in which A and B are both long chain segments; there are also (AB)n type multi-segment copolymers, in which A and B segments are relatively short.
  • BAB type block copolymer refers to a triblock copolymer with an A-block in the middle and B-blocks on both sides.
  • the A-block and the B-block are polymer segments with a predetermined weight average molecular weight formed by polymerization of different monomers.
  • the A-block is a long sequence segment formed by polymerization of a fluorinated monomer
  • the B-block is a polymer segment formed by polymerization of one or more monomers.
  • A-blocks and B-blocks are covalently bonded in an orderly manner to form a BAB type block copolymer.
  • Example 1 of the present application wherein A-block is polyvinylidene fluoride, and the weight average molecular weight is 450,000 g/mol, which is formed by polymerization of vinylidene fluoride monomers; B-block is poly (acrylic acid-acrylamide-ethyl methacrylate), and the weight average molecular weight is 400,000 g/mol, which is formed by polymerization of acrylic acid, ethyl methacrylate and acrylamide monomers;
  • the BAB type block copolymer finally synthesized is poly (acrylic acid-acrylamide-ethyl methacrylate)-polyvinylidene fluoride-poly (acrylic acid-acrylamide-ethyl methacrylate) triblock copolymer, and the weight average molecular weight is 1.2 million g/mol.
  • the A-block of the BAB-type block copolymer contains structural units derived from the monomer of Formula I, and the B-block contains structural units derived from the monomer of Formula II.
  • the A-block in the BAB-type block copolymer contains structural units derived from the monomers represented by Formula I, and the B-block contains structural units derived from the monomers represented by Formula II and Formula III.
  • the A-block in the BAB-type block copolymer contains structural units derived from the monomer represented by Formula II, and the B-block contains structural units derived from the monomer represented by Formula I.
  • the A-block in the BAB type block copolymer contains structural units derived from monomers represented by Formula II and Formula III, and the B-block contains structural units derived from monomers represented by Formula I.
  • the A-block is a long sequence segment formed by the polymerization of one or more fluorine-free monomers
  • the B-block is a long sequence segment formed by the polymerization of one or more fluorine-containing monomers.
  • the A-block and the B-block are covalently bonded in an orderly manner to form a BAB type block copolymer.
  • the A-block is poly (acrylic acid-acrylamide-ethyl methacrylate), which is polymerized by acrylic acid, acrylamide, and ethyl methacrylate monomers, and the weight average molecular weight is 660,000 g/mol;
  • the B-block is polyvinylidene fluoride, which is polymerized by vinylidene fluoride monomers, and the weight average molecular weight is 270,000 g/mol;
  • the end groups on both sides of the B-block and the A-block are bonded to obtain polyvinylidene fluoride-poly (acrylic acid-acrylamide-ethyl methacrylate)-polyvinylidene fluoride block copolymer (BAB type block copolymer), and the weight average molecular weight of the block copolymer is 1.2 million g/mol.
  • polymer includes, on the one hand, a collection of macromolecules that are chemically uniform but differ in degree of polymerization, molar mass and chain length, prepared by polymerization.
  • the term also includes, on the other hand, derivatives of such a collection of macromolecules formed by polymerization, i.e. compounds that can be obtained by reaction, for example addition or substitution, of functional groups in the above-mentioned macromolecules and can be chemically uniform or chemically heterogeneous.
  • ester group refers to a -COOR 11 group, wherein R 11 is selected from an alkyl group which may be substituted or unsubstituted.
  • amide group refers to R 12 and R 13 are each independently selected from hydrogen, and substituted or unsubstituted alkyl.
  • cyano refers to a -CN group.
  • the dispersion medium of the binder is an aqueous solvent, such as water, that is, the binder is dissolved in the aqueous solvent.
  • the dispersion medium of the binder is an oily solvent, examples of which include but are not limited to dimethylacetamide, N,N-dimethylformamide, N-methylpyrrolidone, acetone, dimethyl carbonate, ethyl cellulose, and polycarbonate. That is, the binder is dissolved in the oily solvent.
  • a binder is used to hold the electrode material and/or the conductive agent in place and adhere them to the conductive metal part to form an electrode.
  • the binder is used as a positive electrode binder to bind the positive electrode active material and/or the conductive agent to form an electrode.
  • the binder is used as a negative electrode binder to bind the negative electrode active material and/or the conductive agent to form an electrode.
  • C 1-3 alkyl refers to a straight or branched hydrocarbon chain radical consisting solely of carbon and hydrogen atoms, with no unsaturation in the radical, having from one to three carbon atoms, and attached to the remainder of the molecule by a single bond.
  • Examples of C 1-3 alkyl include, but are not limited to: methyl, ethyl, n-propyl, n-butyl, 1-methylethyl (isopropyl).
  • C 1-5 alkyl refers to a straight or branched chain consisting only of carbon and hydrogen atoms.
  • a hydrocarbon chain radical with no unsaturation in the radical, having from one to five carbon atoms, and attached to the rest of the molecule by a single bond.
  • Examples of C 1-5 alkyl groups include, but are not limited to: methyl, ethyl, n-propyl, 1-methylethyl (isopropyl), n-butyl, tert-butyl, isopentyl.
  • substituted means that at least one hydrogen atom of the compound or chemical moiety is replaced by another chemical moiety with a substituent, wherein the substituent is independently selected from: hydroxyl, thiol, amino, cyano, nitro, aldehyde, halogen atom, alkenyl, alkynyl, aryl, heteroaryl, C 1-6 alkyl, C 1-6 alkoxy.
  • R 1 in Formula I is fluorine
  • R 2 and R 3 are each independently selected from hydrogen, fluorine, chlorine or trifluoromethyl.
  • trifluoromethyl refers to a -CF3 group.
  • the molar content of the structural units derived from the monomers shown in Formula I in the A-block is 30%-70%, based on the total moles of all structural units in the block copolymer.
  • the molar content of the structural units derived from the monomers shown in Formula I in the A-block can be selected from 30%-35%, 35%-40%, 40%-45%, 45%-50%, 50%-55%, 55%-60%, 60%-65%, 65%-70%, 30%-40%, 40%-50%, 50%-60%, 60%-70%, 35%-45%, 45%-55%, 55%-65%, 30%-45%, 45%-60% %, 35%-50%, 50%-65%, 40%-55%, 55%-70%, 30%-50%, 50%-70%, 35%-55%, 40%-60%, 45%-65%, 30%-55%, 35%-60%, 40%-65%, 45%-70%, 30%-60%, 35%-65%, 40%-70%, 30%-65%, 35%-70%, based on the total moles of all structural units
  • the bonding force of the electrode will decrease; if the molar content of the structural unit derived from the monomer shown in Formula I in the A-block is too high, the gelation of the slurry will be accelerated, the slurry stability will be reduced, and the membrane resistance will increase.
  • Controlling the molar content of the structural unit derived from the monomer represented by Formula I in the A-block within a suitable range can effectively slow down the gelation of the slurry, improve the stability of the slurry, increase the flexibility of the pole piece, reduce the membrane resistance, and improve the cycle capacity retention rate of the battery.
  • the structural units derived from the monomers of Formula I in the A-block are The molar content is 40%-60%, based on the total moles of all structural units in the block copolymer.
  • the molar content of the structural unit derived from the monomer shown in Formula I in the A-block can be selected from any one of 40%-45%, 45%-50%, 50%-55%, 55%-60%, 40%-50%, 50%-60%, 45%-55%, 45%-60%, 40%-55%, 40%-60%, 45%-65%, based on the total moles of all structural units in the block copolymer.
  • the DC impedance growth rate and the cycle capacity retention rate of the battery can be taken into account, thereby comprehensively improving the electrochemical performance of the battery.
  • the molar content of the structural unit derived from the monomer shown in Formula I in the B-block is 30%-70%, based on the total moles of all structural units in the block copolymer.
  • the molar content of the structural unit derived from the monomer shown in Formula I in the B-block can be selected from 30%-35%, 35%-40%, 40%-45%, 45%-50%, 50%-55%, 55%-60%, 60%-65%, 65%-70%, 30%-40%, 40%-50%, 50%-60%, 60%-70%, 35%-45%, 45%-55%, 55%-65%, 30%-45%, 45%-60% %, 35%-50%, 50%-65%, 40%-55%, 55%-70%, 30%-50%, 50%-70%, 35%-55%, 40%-60%, 45%-65%, 30%-55%, 35%-60%, 40%-65%, 45%-70%, 30%-60%, 35%-65%, 40%-70%, 30%-65%, 35%-70%, based on the total moles of all structural units
  • Controlling the molar content of the structural unit derived from the monomer represented by Formula I in the B-block within a suitable range can slow down the gelation of the slurry, improve the stability of the slurry, reduce the film resistance of the pole piece, and reduce the DC impedance growth rate of the battery.
  • the molar content of the structural unit derived from the monomer shown in Formula I in the B-block is 40%-60%, based on the total moles of all structural units in the block copolymer. In some embodiments, the molar content of the structural unit derived from the monomer shown in Formula I in the B-block can be selected from any one of 40%-45%, 45%-50%, 50%-55%, 55%-60%, 40%-50%, 50%-60%, 45%-55%, 45%-60%, 35%-50%, 50%-65%, 40%-55%, 40%-60%, based on the total moles of all structural units in the block copolymer.
  • the weight average molecular weight of the block copolymer is 400,000-2,000,000. In some embodiments, the weight average molecular weight of the block copolymer can be selected from 400,000-600,000, 600,000-800,000, 800,000-1,000,000, 1,000,000-1,200,000, 1,200,000-1,400,000, 1,400,000-1,600,000, 1,600,000-1,800,000, 1,800,000-2,000,000, 600,000-900,000, 900,000-1,200,000, 1,200,000-1,500,000, 1,500,000-1,800,000, 1,800,000-2,000,000, and any one of 1,200,000-2,000,000.
  • weight average molecular weight refers to the sum of the products of the weight fractions of molecules with different molecular weights in a polymer and their corresponding molecular weights.
  • the binder will be difficult to dissolve and will easily agglomerate with the conductive agent, increasing the internal resistance of the diaphragm.
  • the viscosity of the slurry will be relatively large, reducing the dispersion of the bonding and affecting the flexibility of the electrode.
  • the weight-average molecular weight of the block copolymer is too small, it will be difficult to form a three-dimensional network bonding structure, and it will not be able to play an effective bonding role.
  • the internal resistance of the diaphragm will increase.
  • Controlling the weight-average molecular weight of the block copolymer within an appropriate range can effectively slow down the gelation of the slurry, improve the stability of the slurry, increase the flexibility of the pole piece, increase the bonding force, reduce the membrane resistance, reduce the DC impedance growth rate of the battery, and improve the cycle capacity retention rate of the battery.
  • the weight average molecular weight of the A-block containing the structural unit derived from the monomer shown in Formula I is 200,000-1,050,000. In some embodiments, the weight average molecular weight of the A-block containing the structural unit derived from the monomer shown in Formula I can be selected from any one of 200,000-300,000, 300,000-400,000, 400,000-500,000, 500,000-600,000, 600,000-700,000, 700,000-800,000, 800,000-900,000, 900,000-1,050,000, 400,000-600,000, 400,000-800,000, and 400,000-1,050,000.
  • the weight average molecular weight of the A-block containing the structural unit derived from the monomer shown in Formula I in the block copolymer is too large, the structural unit derived from the monomer shown in Formula I has too many strong polar groups, which affects the stability of the slurry; if the block copolymer contains the structural unit derived from the monomer shown in Formula I If the weight average molecular weight of the A-block of the unit is too small, the bonding strength of the electrode sheet will decrease.
  • Controlling the weight average molecular weight of the A-block containing the structural unit derived from the monomer represented by Formula I in the block copolymer within a suitable range can effectively slow down the gelation of the slurry, improve the stability of the slurry, improve the flexibility of the pole piece, reduce the membrane resistance, and improve the cycle capacity retention rate of the battery.
  • the weight average molecular weight of the A-block containing the structural unit derived from the monomer shown in formula II or the structural unit derived from the monomer shown in formula II and the structural unit derived from the monomer shown in formula III is 200,000-1,050,000.
  • the weight average molecular weight of the A-block containing the structural unit derived from the monomer shown in formula II or the structural unit derived from the monomer shown in formula II and the structural unit derived from the monomer shown in formula III can be selected from any one of 200,000-300,000, 300,000-400,000, 400,000-500,000, 500,000-600,000, 600,000-700,000, 700,000-800,000, 800,000-900,000, 900,000-1,050,000, 400,000-600,000, 400,000-800,000, and 400,000-1,050,000.
  • the bonding force of the pole piece can be improved and the DC impedance growth rate of the battery can be reduced.
  • the weight average molecular weight of each B-block containing a structural unit derived from a monomer shown in formula II or containing a structural unit derived from a monomer shown in formula II and a structural unit derived from a monomer shown in formula III is 100,000-500,000.
  • the weight average molecular weight of each B-block containing a structural unit derived from a monomer shown in formula II or containing a structural unit derived from a monomer shown in formula II and a structural unit derived from a monomer shown in formula III can be selected from any one of 100,000-200,000, 200,000-300,000, 300,000-400,000, 400,000-500,000, 200,000-400,000, and 200,000-500,000.
  • Controlling the weight average molecular weight of each B-block in the block copolymer containing a structural unit derived from the monomer shown in formula II or containing a structural unit derived from the monomer shown in formula II and a structural unit derived from the monomer shown in formula III within a suitable range can improve the bonding force and improve the cycle capacity retention rate of the battery.
  • each of the block copolymers contains a The weight average molecular weight of the B-block containing the structural unit derived from the monomer shown in Formula I is 100,000-500,000. In some embodiments, the weight average molecular weight of each B-block containing the structural unit derived from the monomer shown in Formula I can be selected from any one of 100,000-200,000, 200,000-300,000, 300,000-400,000, 400,000-500,000, 200,000-400,000, and 200,000-500,000.
  • Controlling the weight average molecular weight of each B-block containing a structural unit derived from the monomer represented by Formula I in the block copolymer within a suitable range can effectively slow down the gelation of the slurry, improve the stability of the slurry, reduce the membrane resistance, and reduce the DC impedance growth rate of the battery.
  • the monomer represented by formula I is selected from one or more of vinylidene fluoride, tetrafluoroethylene, vinyl fluoride, and hexafluoropropylene.
  • the monomer represented by formula II is selected from one or more of acrylic acid, methacrylic acid, and ethacrylic acid.
  • the monomer of formula III is selected from one or more of acrylamide, acrylate, and acrylonitrile. In some embodiments, the monomer of formula III is selected from one or more of acrylamide, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, methyl ethyl acrylate, ethyl ethyl acrylate, and acrylonitrile. In some embodiments, the monomer of formula III is selected from one or more of acrylamide, ethyl methacrylate, and acrylonitrile.
  • the BAB-block copolymer is a polyacrylic acid-polyvinylidene fluoride-polyacrylic acid triblock copolymer, a polyacrylic acid-polyvinyl fluoride-polyacrylic acid triblock copolymer, a polyacrylic acid-polytetrafluoroethylene-polyacrylic acid triblock copolymer, a poly(acrylic acid-acrylate)-polyvinylidene fluoride-poly(acrylic acid-acrylate) triblock copolymer, a poly(acrylic acid-acrylate)-polyvinyl fluoride-poly(acrylic acid-acrylate) triblock copolymer, a poly(acrylic acid-acrylate)-polyvinyl fluoride-poly(acrylic acid-acrylate) triblock copolymer, a poly(acrylic acid-acrylate)-polyvinyl fluoride-poly(acrylic acid-acrylate) triblock copolymer, a poly
  • the BAB-block copolymer is a poly(vinylidene fluoride-hexafluoropropylene)-poly(acrylic acid-acrylamide-acrylate)-poly(vinylidene fluoride-hexafluoropropylene) triblock copolymer, a polyvinyl fluoride-polyacrylic acid-polyvinyl fluoride, a polytetrafluoroethylene-polyacrylic acid-polytetrafluoroethylene triblock copolymer, a polyvinylidene fluoride-poly(acrylic acid-acrylate)-polyvinylidene fluoride triblock copolymer, a polyvinyl fluoride-poly(acrylic acid-acrylate)-polyvinylidene fluoride triblock copolymer, a polytetrafluoroethylene-poly(acrylic acid-acrylate)-polytetrafluoroethylene triblock copolymer
  • the present invention relates to a polyvinylidene fluoride triblock copolymer, a polyvinyl fluoride-poly(acrylic acid-acrylamide-acrylate)-polyvinylidene fluoride triblock copolymer, a polytetrafluoroethylene-poly(acrylic acid-acrylamide-acrylate)-polytetrafluoroethylene triblock copolymer, a polyvinylidene fluoride-poly(acrylic acid-acrylonitrile)-polyvinylidene fluoride triblock copolymer, a polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylamide)-polyvinylidene fluoride triblock copolymer, a polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylamide)-polyvinylidene fluoride triblock copolymer, a polyvinylidene fluoride-poly(acryl
  • acrylate refers to the general term for esters of acrylic acid and its homologues, examples of which include, but are not limited to, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, and the like.
  • the fluorine element contained in the A-block forms hydrogen bonds with the hydroxyl and/or carboxyl groups on the surface of the positive electrode active material and the current collector, so that the pole piece has excellent adhesion.
  • the strong polar group carboxyl group in the B-block can form strong hydrogen bonds and dipole-dipole interactions with the hydroxyl groups on the surface of the positive electrode active material, thereby improving the adhesion of the pole piece, improving the dispersibility of the binder for the substances in the slurry, and reducing the membrane resistance.
  • the amount of binder added to the slurry can be reduced.
  • the strong polar group carboxyl group can enhance the stability of the molecular structure, increase the glass transition temperature of the copolymer, improve the rigidity and thermal stability of the copolymer, help improve the oxidation stability of the positive electrode material, and greatly improve the cycle performance of the battery.
  • the binder prepared with the BAB type block copolymer can maximize the weight average molecular weight of the fluorine-containing block and the non-fluorine block, give full play to the respective advantages of the fluorine-containing binder and the non-fluorine binder, and achieve the role of complementary advantages.
  • the binder prepared with BAB type block copolymer can effectively slow down the gelation phenomenon of the slurry, improve the stability of the slurry, improve the flexibility of the electrode, improve the bonding force, reduce the membrane resistance, reduce the DC impedance growth rate of the battery, and/or improve the cycle capacity retention rate of the battery.
  • the fluorine element contained in the B-block forms hydrogen bonds with the hydroxyl and/or carboxyl groups on the surface of the positive electrode active material and the current collector, so that the pole piece has excellent adhesion.
  • the strong polar group carboxyl group in the A-block can form strong hydrogen bonds and dipole-dipole interactions with the hydroxyl groups on the surface of the positive electrode active material, thereby improving the adhesion of the pole piece, improving the dispersibility of the binder for the substances in the slurry, and reducing the membrane resistance.
  • the amount of binder added to the slurry can be reduced.
  • the strong polar group carboxyl group can enhance the stability of the molecular structure, increase the glass transition temperature of the copolymer, improve the rigidity and thermal stability of the copolymer, help improve the oxidation stability of the positive electrode material, and can greatly improve the electrical The circulation performance of the pool.
  • the binder prepared with the BAB type block copolymer can maximize the weight average molecular weight of the fluorine-containing block and the non-fluorine block, give full play to the respective advantages of the fluorine-containing binder and the non-fluorine binder, and achieve the role of complementary advantages.
  • the binder prepared with BAB type block copolymer can effectively slow down the gelation phenomenon of the slurry, improve the stability of the slurry, improve the flexibility of the electrode, improve the bonding force, reduce the membrane resistance, reduce the DC impedance growth rate of the battery, and/or improve the cycle capacity retention rate of the battery.
  • a method for preparing a BAB type block copolymer comprising the following steps:
  • Preparation of A-block polymerizing at least one monomer represented by formula I to prepare A-block,
  • the A-block is prepared by polymerizing monomer units, wherein the monomer units include at least one monomer represented by formula II,
  • R 1 , R 2 , and R 3 are each independently selected from one or more of hydrogen, fluorine, and C 1-3 alkyl containing at least one fluorine atom; and R 4 , R 5 , and R 6 are each independently selected from hydrogen, and substituted or unsubstituted C 1-5 alkyl;
  • B-block polymerizing monomer units to prepare B-block, wherein the monomer units include at least one monomer represented by formula II,
  • At least one monomer of formula I is polymerized to prepare a B-block
  • Preparation of a BAB type block copolymer The A-block and the B-block are joined to prepare a BAB type block copolymer, wherein the A-block and the B-block contain different structural units.
  • the monomer unit further comprises at least one monomer represented by formula III,
  • R 7 , R 8 and R 9 are each independently selected from hydrogen, substituted or unsubstituted C 1-5 alkyl, and R 10 is selected from one of ester group, cyano group and amide group.
  • a method for preparing a BAB type block copolymer comprising the following steps:
  • Preparation of A-block polymerizing at least one monomer represented by formula I to prepare A-block,
  • B-block polymerizing at least one monomer represented by formula II to prepare B-block,
  • BAB-type block copolymers A-blocks and B-blocks are joined to prepare BAB-type block copolymers, wherein the A-blocks and the B-blocks contain different structural units.
  • a method for preparing a BAB type block copolymer comprising the following steps:
  • Preparation of A-block polymerizing at least one monomer represented by formula I to prepare A-block,
  • B-block polymerizing at least one monomer represented by formula II and at least one monomer represented by formula III to prepare B-block,
  • BAB-type block copolymers A-blocks and B-blocks are joined to prepare BAB-type block copolymers, wherein the A-blocks and the B-blocks contain different structural units.
  • a method for preparing a BAB type block copolymer comprising the following steps:
  • Preparation of A-block polymerizing at least one monomer represented by formula II to prepare A-block,
  • B-block polymerizing at least one monomer represented by formula I to prepare B-block,
  • BAB-type block copolymers A-blocks and B-blocks are joined to prepare BAB-type block copolymers, wherein the A-blocks and the B-blocks contain different structural units.
  • a method for preparing a BAB type block copolymer comprising the following steps:
  • Preparation of A-block polymerizing at least one monomer represented by formula II and at least one monomer represented by formula III to prepare A-block,
  • B-block polymerizing at least one monomer represented by formula I to prepare B-block,
  • BAB-type block copolymers A-blocks and B-blocks are joined to prepare BAB-type block copolymers, wherein the A-blocks and the B-blocks contain different structural units.
  • FIG1 a schematic diagram of a method for preparing a BAB-type block copolymer 6 is shown in FIG1 , wherein the end groups 611 of an A-block 61 prepared by polymerization of a monomer or monomer unit shown in Formula I are active groups, and the terminal groups 621 of a B-block 62 prepared by polymerization of a monomer unit or a monomer shown in Formula I are active groups, and the end groups 611 of the A-block react with the terminal groups 621 of the B-block to achieve bonding of polymer segments, thereby preparing a BAB-type block copolymer 6.
  • the preparation method has cheap raw materials, can reduce costs, reduce environmental pollution, and is conducive to the improvement of binder production.
  • the binder prepared by the method can effectively slow down the gelation phenomenon of the slurry, improve the stability of the slurry, improve the flexibility of the pole piece, improve the bonding force, reduce the membrane resistance, reduce the DC impedance growth rate of the battery, and/or improve the cycle capacity retention rate of the battery.
  • the method of preparing the A-block comprises:
  • At least one monomer or monomer unit represented by formula I and a second initiator are polymerized at a reaction temperature of 80-95° C. for 2.5-5 hours, and the terminal groups of the product are substituted to prepare the A-block having azide groups or alkynyl groups as terminal groups at both ends.
  • azide group refers to a -N3 group.
  • alkynyl refers to a -C ⁇ C group.
  • the method of preparing the A-block comprises:
  • At least one monomer represented by formula I and a second initiator are polymerized at a reaction temperature of 80-95° C. for 2.5-5 hours, and the terminal groups of the products are substituted to prepare the A-block having azide groups or alkynyl groups as terminal groups at both ends.
  • the synthesis route of the A-block is as follows: under the action of the second initiator, the monomer shown in Formula I undergoes a polymerization reaction to generate the A-block. Since the terminal groups on both sides of the second initiator are halogen-substituted alkyl or trimethylsilyl acetylene groups, the halogen or trimethylsilyl groups on both sides of the A-block are easily substituted, so that both ends of the A-block have azide groups. or alkynyl.
  • the azide-terminated A-block prepared by the preparation method facilitates the A-block to be connected with the B-block in an efficient and mild manner to generate a BAB-type block copolymer.
  • At least one monomer unit and a second initiator are polymerized at a reaction temperature of 80-95° C. for 2.5-5 hours, and the end groups of the product are subjected to a substitution reaction to prepare the A-block having azide groups or alkynyl groups as end groups at both ends.
  • the synthesis route of the A-block is as follows, and under the action of the second initiator, the monomer unit undergoes a polymerization reaction to generate the A-block. Since the end groups on both sides of the second initiator are halogen-substituted alkyl or trimethylsilyl acetylene groups, the halogen or trimethylsilyl groups on both sides of the A-block are easily substituted, so that both ends of the A-block have an azide group or an alkynyl group.
  • x is the degree of polymerization of the structural unit derived from the monomer shown in formula II
  • y is the degree of polymerization of the structural unit derived from the monomer shown in formula III
  • x is a positive integer greater than zero
  • y can be zero or a positive integer greater than zero.
  • the A-block contains structural units derived from the monomer shown in formula II and structural units derived from the monomer shown in formula III
  • the A-block can be a random copolymer, a block copolymer or an alternating copolymer.
  • the method of preparing the B-block comprises:
  • At least one monomer or monomer unit of formula I, a chain transfer agent and a first initiator are subjected to reversible addition-fragmentation chain transfer polymerization at a reaction temperature of 60-80° C. for 4.5-7 hours to obtain the B-block having an alkynyl or azide group as an end group.
  • RAFT polymerization is a type of reversibly deactivated free radical polymerization, also known as a "living"/controlled free radical polymerization method.
  • the main principle of RAFT polymerization is to add a RAFT agent as a chain transfer agent to the free radical polymerization, and protect the easily terminated free radicals through chain transfer, so that most of the free radicals in the polymerization reaction are converted into dormant free radicals.
  • dormant segments and active segments exist at the same time and are constantly and rapidly switched with each other through dynamic reversible reactions, resulting in only a few polymer chains existing in the form of active chains and growing at any one time, which ultimately makes the growth probability of each polymer segment roughly equal, thus showing the characteristics of living polymerization.
  • the monomer unit, chain transfer agent and first initiator are polymerized by reversible addition-fragmentation chain transfer at a reaction temperature of 60-80° C. for 4.5-7 hours to obtain the B-block having an alkynyl group or an azide group as a terminal group.
  • the synthesis route of the B-block is as follows, wherein the chain transfer agent is trithiocarbonate, Z' is an active group containing an alkynyl or azide group at the end, and R is an alkyl group.
  • the B-block having an alkynyl or azide group at the end is prepared by the following reaction, wherein m is the degree of polymerization of the structural unit derived from the monomer represented by formula II, n is the degree of polymerization of the structural unit derived from the monomer represented by formula III, m is a positive integer greater than zero, and n can be zero or A positive integer greater than 0.
  • the B-block may be a random copolymer, a block copolymer or an alternating copolymer.
  • random copolymer refers to a disordered copolymer formed by copolymerization of two or more monomers.
  • alternating copolymer refers to a copolymer in which two or more structural units are arranged alternately in a polymer chain.
  • the method of preparing the B-block comprises:
  • At least one monomer of formula I, a chain transfer agent and a second initiator are polymerized by reversible addition-fragmentation chain transfer at a reaction temperature of 60-80° C. for 4.5-7 hours to obtain a B-block having an alkynyl or azide group at the end.
  • the synthesis route of the B-block is shown in the figure below, wherein the chain transfer agent is trithiocarbonate, Z' is an active group having an alkynyl or azide group at the end, and R is an alkyl group.
  • the B-block having an alkynyl or azide group at the end is prepared by the following reaction.
  • the reversible addition-fragmentation chain transfer polymerization can achieve controllable polymerization, and the molecular weight distribution of the product is relatively narrow.
  • the B-block only has an alkynyl or azide group at the end, which is convenient for directing the bonding with the A-block in an efficient and gentle manner to generate a BAB-type triblock. Block copolymer.
  • the method of preparing a BAB-type block copolymer comprises:
  • the A-block having an azide group or an alkynyl group as an end group at both ends is mixed with the B-block having an alkynyl group or an azide group as an end group at the end, and a click reaction is performed to prepare a BAB type block copolymer, wherein the end groups of the A-block and the B-block are different.
  • click reaction refers to a cycloaddition reaction between an alkynyl group and an azide group, so that the A-block is connected to the B-block.
  • the click reaction is carried out in the presence of a Cu(I) catalyst at room temperature and pressure.
  • the terminal group of the A-block is an azide group and the terminal group of the B-block is an alkynyl group.
  • the terminal group of the A-block is an alkynyl group and the terminal group of the B-block is an azide group.
  • the above preparation method has the advantages of high yield, harmless by-products, simple and mild reaction conditions, and readily available reaction raw materials. It can achieve controlled polymerization of block polymers, which is beneficial to improving the yield rate of products.
  • the chain transfer agent is a RAFT chain transfer agent containing a terminal alkynyl or azide group. In some embodiments, the chain transfer agent is a trithiocarbonate containing a terminal alkynyl or azide group. In some embodiments, the structural formula of the chain transfer agent is selected from the following formula,
  • the RAFT chain transfer agent containing terminal alkynyl or azide groups makes the terminal of B-block carry alkynyl or azide groups during the synthesis of B-block, which is the point of occurrence of B-block and A-block. It provides a basis for the knock-in reaction, avoids complicated post-processing steps, and can improve the reaction efficiency.
  • the first initiator is an azo initiator selected from one or more of azobisisobutyronitrile and azobisisoheptanenitrile.
  • Azo initiator is a commonly used free radical polymerization initiator, which is easy to decompose to form free radicals, and is convenient for initiating free radical polymerization.
  • the second initiator is a symmetrical bifunctional initiator selected from 4-(chloromethyl)benzoyl peroxide.
  • the symmetrical bifunctional initiator allows both sides of the A-block to symmetrically carry the same active functional groups, which helps to achieve simultaneous azidation or alkyneation of the terminal groups on both sides of the A-block.
  • the BAB type block copolymer may be used in a secondary battery.
  • the secondary battery includes at least one of a lithium ion battery, a sodium ion battery, a magnesium ion battery, and a potassium ion battery.
  • the positive electrode plate includes a positive electrode current collector and a positive electrode film layer arranged on at least one surface of the positive electrode current collector, wherein the positive electrode film layer includes a positive electrode active material, a conductive agent and a binder, wherein the binder is a BAB type block copolymer in some embodiments or a BAB type block copolymer prepared by a preparation method in some embodiments.
  • the positive electrode sheet has excellent flexibility, adhesion and/or low film resistance.
  • the mass fraction of the binder is 0.1%-3%, based on the total mass of the positive electrode active material. In some embodiments, the mass fraction of the binder can be selected from any one of 0.1%-0.2%, 0.1%-1%, 0.1%-1.2%, 0.2%-1%, 0.2%-1.2%, 0.2%-3%, 1%-1.2%, 1%-3%, 1.2%-3%, based on the total mass of the positive electrode active material.
  • the binder When the binder content is too low, the binder cannot exert sufficient bonding effect. On the one hand, the binder cannot fully disperse the conductive agent and active material, resulting in an increase in the film resistance of the electrode; on the other hand, the positive electrode active material and conductive agent in the slurry cannot be tightly combined with the binder, and the positive electrode active material and conductive agent particles settle and agglomerate, and the stability of the slurry decreases.
  • Controlling the mass fraction of the binder within a reasonable range can significantly slow down the gelation of the slurry, improve the stability of the slurry, increase the flexibility of the electrode, and improve the cycle capacity retention rate of the battery.
  • the bonding force per unit length between the positive electrode film layer and the positive electrode current collector is not less than 8 N/m. In some embodiments, the bonding force per unit length between the positive electrode film layer and the positive electrode current collector is not less than 10 N/m.
  • the bonding force per unit length between the positive electrode film layer and the positive electrode current collector can be tested by any means known in the art, such as testing with reference to GB-T2790-1995 national standard "Adhesive 180° Peel Strength Test Method".
  • the positive electrode sheet is cut into a test sample of 20mm ⁇ 100mm size for standby use; the electrode sheet is bonded to one side of the positive electrode film layer with double-sided tape, and compacted with a roller to make the double-sided tape and the electrode sheet completely fit; the other side of the double-sided tape is attached to the stainless steel surface, and one end of the sample is bent in the opposite direction with a bending angle of 180°; the high-speed rail tensile machine is used for testing, one end of the stainless steel is fixed to the lower fixture of the tensile machine, the bent end of the sample is fixed to the upper fixture, the angle of the sample is adjusted to ensure that the upper and lower ends are in a vertical position, and then the sample is stretched at a speed of 50mm/min until the
  • the force when the force is balanced divided by the width of the electrode attached to the double-sided tape (the width direction of the electrode is perpendicular to the peeling direction) is taken as the bonding force of the electrode per unit length.
  • the width of the electrode is 20mm.
  • the positive electrode film layer of the pole piece has high bonding strength with the positive electrode current collector. During use, the positive electrode film layer is not easy to fall off from the positive electrode current collector, which helps to improve the cycle performance and safety of the battery.
  • the positive electrode plate after the positive electrode plate has been subjected to no less than three bending tests, the positive electrode plate becomes light-transmissive.
  • the bending test also known as the flexibility test, can be used to test the flexibility of the electrode.
  • the test can be performed by any means known in the art.
  • the cold-pressed positive electrode is cut into a test specimen of 20mm ⁇ 100mm in size; it is folded in half, flattened with a 2kg roller, and unfolded to check whether there is light transmission through the gap. If no light is transmitted, Then fold it in the opposite direction, flatten it with a 2kg roller, and check it again against the light. Repeat this process until light is translucent through the gap and record the number of folds. Take at least three samples for testing and take the average value as the test result of the bending test.
  • the electrode can undergo no less than 3 bending tests, indicating that the electrode has good flexibility and is not prone to cracking during the production process or brittle breakage during use, which helps to improve the yield rate of the battery and improve the safety performance of the battery.
  • the sheet resistance of the positive electrode sheet is ⁇ 0.52 ⁇ . In some embodiments, the sheet resistance of the positive electrode sheet is ⁇ 0.46 ⁇ .
  • the diaphragm resistance test can be used to test the resistance of the electrode.
  • the test can be performed by any means known in the art. As an example, cut small discs with a diameter of 20 mm from the left, middle, and right sides of the electrode; turn on the indicator light of the Yuanneng Technology electrode resistance meter, place the probe in the appropriate position of the diaphragm resistance meter, click the "start" button, wait for the reading to stabilize, and then read it; test two positions of each small disc, and finally calculate the average of six measurements, which is the diaphragm resistance of the electrode.
  • the positive electrode current collector has two surfaces opposite to each other in its thickness direction, and the positive electrode film layer is disposed on any one or both of the two opposite surfaces of the positive electrode current collector.
  • the positive electrode current collector may be a metal foil or a composite current collector.
  • the metal foil aluminum foil may be used.
  • the composite current collector may include a polymer material base and a metal layer formed on at least one surface of the polymer material base.
  • the composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).
  • PP polypropylene
  • PET polyethylene terephthalate
  • PBT polybutylene terephthalate
  • PS polystyrene
  • PE polyethylene
  • the positive electrode active material may be a positive electrode active material for a battery known in the art.
  • the positive electrode active material may include at least one of the following materials: an olivine-structured lithium-containing phosphate, a lithium transition metal oxide, and their respective modified compounds.
  • the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials for batteries may also be used.
  • These positive electrode active materials may be used alone, Two or more kinds may be used in combination.
  • lithium transition metal oxides may include, but are not limited to , lithium cobalt oxide (such as LiCoO2 ), lithium nickel oxide (such as LiNiO2 ), lithium manganese oxide (such as LiMnO2 , LiMn2O4 ), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi1 / 3Co1 / 3Mn1 / 3O2 (also referred to as NCM333 ), LiNi0.5Co0.2Mn0.3O2 (also referred to as NCM523 ) , LiNi0.5Co0.25Mn0.25O2 (also referred to as NCM211 ) , LiNi0.6Co0.2Mn0.2O2 (also referred to as NCM622 ), LiNi0.8Co0.1Mn0.1O2 (also referred to as NCM811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05
  • lithium-containing phosphates with an olivine structure may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO 4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO 4 ), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon.
  • lithium iron phosphate such as LiFePO 4 (also referred to as LFP)
  • LiMnPO 4 lithium manganese phosphate
  • LiMnPO 4 lithium manganese phosphate
  • LiMnPO 4 lithium manganese phosphate and carbon
  • the positive electrode film layer may further include a conductive agent, which may include, for example, at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.
  • a conductive agent which may include, for example, at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.
  • the positive electrode sheet can be prepared in the following manner: the components for preparing the positive electrode sheet, such as the positive electrode active material, the conductive agent, the binder and any other components are dispersed in a solvent (such as N-methylpyrrolidone) to form a positive electrode slurry; the positive electrode slurry is coated on the positive electrode collector, and after drying, cold pressing and other processes, the positive electrode sheet can be obtained.
  • a solvent such as N-methylpyrrolidone
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode film layer disposed on at least one surface of the negative electrode current collector, wherein the negative electrode film layer includes a negative electrode active material.
  • the negative electrode current collector has two surfaces opposite to each other in its thickness direction, and the negative electrode film layer is disposed on any one or both of the two opposite surfaces of the negative electrode current collector.
  • the negative electrode current collector may be a metal foil or a composite current collector.
  • a metal foil a copper foil may be used.
  • the composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer.
  • the fluid can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).
  • PP polypropylene
  • PET polyethylene terephthalate
  • PBT polybutylene terephthalate
  • PS polystyrene
  • PE polyethylene
  • the negative electrode active material may adopt the negative electrode active material for the battery known in the art.
  • the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc.
  • the silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys.
  • the tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys.
  • the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.
  • the negative electrode film layer may further include a binder.
  • the binder may be selected from at least one of styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA) and carboxymethyl chitosan (CMCS).
  • the negative electrode film layer may further include a conductive agent, which may be selected from at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.
  • a conductive agent which may be selected from at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.
  • the negative electrode film layer may optionally include other additives, such as a thickener (eg, sodium carboxymethyl cellulose (CMC-Na)).
  • a thickener eg, sodium carboxymethyl cellulose (CMC-Na)
  • the negative electrode sheet can be prepared in the following manner: the components for preparing the negative electrode sheet, such as the negative electrode active material, the conductive agent, the binder and any other components are dispersed in a solvent (such as deionized water) to form a negative electrode slurry; the negative electrode slurry is coated on the negative electrode collector, and after drying, cold pressing and other processes, the negative electrode sheet can be obtained.
  • a solvent such as deionized water
  • the electrolyte plays the role of conducting ions between the positive electrode and the negative electrode.
  • the present application has no specific restrictions on the type of electrolyte, which can be selected according to needs.
  • the substance can be liquid, gel or completely solid.
  • the electrolyte is an electrolyte solution, which includes an electrolyte salt and a solvent.
  • the electrolyte salt can be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.
  • the solvent can be selected from at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclopentane sulfone, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone.
  • the electrolyte may further include additives, such as negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain battery properties, such as additives that improve battery overcharge performance, additives that improve battery high or low temperature performance, etc.
  • additives such as negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain battery properties, such as additives that improve battery overcharge performance, additives that improve battery high or low temperature performance, etc.
  • the secondary battery further includes a separator.
  • the present application has no particular limitation on the type of separator, and any known porous separator with good chemical stability and mechanical stability can be selected.
  • the material of the isolation membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride.
  • the isolation membrane can be a single-layer film or a multi-layer composite film, without particular limitation.
  • the materials of each layer can be the same or different, without particular limitation.
  • the positive electrode sheet, the negative electrode sheet, and the separator may be formed into an electrode assembly by a winding process or a lamination process.
  • the secondary battery may include an outer package, which may be used to encapsulate the electrode assembly and the electrolyte.
  • the outer packaging of the secondary battery may be a hard shell, such as a hard plastic shell, an aluminum shell, a steel shell, etc.
  • the outer packaging of the secondary battery may also be a soft package, such as a bag-type soft package.
  • the material of the soft package may be plastic, and examples of the plastic include polypropylene, polybutylene terephthalate, and polybutylene succinate.
  • FIG2 is a secondary battery 5 of a square structure as an example.
  • the secondary battery may also be a sodium ion battery, a magnesium ion battery, or a potassium ion battery.
  • the outer package may include a shell 51 and a cover plate 53.
  • the shell 51 may include a bottom plate and a side plate connected to the bottom plate, and the bottom plate and the side plate enclose a receiving cavity.
  • the shell 51 has an opening connected to the receiving cavity, and the cover plate 53 can be covered on the opening to close the receiving cavity.
  • the positive electrode sheet, the negative electrode sheet and the isolation film can form an electrode assembly 52 through a winding process or a lamination process.
  • the electrode assembly 52 is encapsulated in the receiving cavity.
  • the electrolyte is infiltrated in the electrode assembly 52.
  • the number of electrode assemblies 52 contained in the secondary battery 5 can be one or more, and those skilled in the art can select according to specific actual needs.
  • secondary batteries may be assembled into a battery module.
  • the number of secondary batteries contained in the battery module may be one or more, and the specific number may be selected by those skilled in the art according to the application and capacity of the battery module.
  • FIG4 is a battery module 4 as an example.
  • a plurality of secondary batteries 5 may be arranged in sequence along the length direction of the battery module 4. Of course, they may also be arranged in any other manner. Further, the plurality of secondary batteries 5 may be fixed by fasteners.
  • the battery module 4 may further include a housing having a housing space, and the plurality of secondary batteries 5 are housed in the housing space.
  • the battery modules can also be assembled into a battery pack.
  • the number of battery modules included may be one or more, and the specific number can be selected by those skilled in the art according to the application and capacity of the battery pack.
  • FIG5 and FIG6 are battery packs 1 as an example.
  • the battery pack 1 may include a battery box and a plurality of battery modules 4 disposed in the battery box.
  • the battery box includes an upper box body 2 and a lower box body 3, and the upper box body 2 can be covered on the lower box body 3 to form a closed space for accommodating the battery modules 4.
  • the plurality of battery modules 4 can be arranged in the battery box in any manner.
  • an electric device comprising at least one of a secondary battery of any embodiment, a battery module of any embodiment, or a battery pack of any embodiment.
  • the electrical device includes at least one of the secondary battery, battery module, or battery pack provided in the present application.
  • the secondary battery, battery module, or battery pack can be used as a power source for the electrical device, and can also be used as an energy storage unit for the electrical device.
  • the electrical device may include mobile devices (such as mobile phones, laptops, etc.), electric vehicles (such as pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc., but are not limited thereto.
  • a secondary battery, a battery module or a battery pack may be selected according to its usage requirements.
  • FIG7 is an example of an electric device.
  • the electric device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle.
  • a battery pack or a battery module may be used.
  • a device may be a mobile phone, a tablet computer, a notebook computer, etc. Such a device is usually required to be thin and light, and a secondary battery may be used as a power source.
  • Preparation of B-block using an alkynyl compound as a chain transfer agent to prepare alkynyl-terminated poly(acrylic acid-acrylamide-ethyl methacrylate) by polymerization reaction;
  • Acrylic acid, ethyl methacrylate and acrylamide were weighed in a molar ratio of 8:1:1, 500 ml of tetrahydrofuran was measured, added to a four-necked flask, a large amount of nitrogen was introduced, and the stirring speed was gradually increased to 1200 rpm, 1% of the monomer mass of RAFT chain transfer agent (CTA-alkyne) and 0.1% of the monomer mass of azobisisobutyronitrile were added, and the temperature was raised to 75°C. After 6 hours of reaction, the reaction was terminated by cooling in liquid nitrogen, and the solution was precipitated in excess methanol. The polymer was collected by filtration and reprecipitated twice from chloroform with methanol.
  • CTA-alkyne RAFT chain transfer agent
  • azobisisobutyronitrile azobisisobutyronitrile
  • the resulting product was vacuum dried overnight at room temperature to remove all traces of residual solvents to obtain a poly (acrylic acid-acrylamide-ethyl methacrylate) with an alkynyl-capped single end having a weight average molecular weight of 400,000, i.e., a B-block polymer.
  • Polyvinylidene fluoride blocked at both ends by azide, poly(acrylic acid-acrylamide-ethyl methacrylate) blocked at one end by alkyne, and cuprous bromide were added to a dry Schlenk tube in a molar ratio of 1:2.5:4. After degassing, 4 ml of anhydrous N,N-dimethylformamide (DMF) and 0.14 mmol N,N,N',N,'N"-pentamethyldiethylenetriamine (PMDETA) were added. The reaction was stirred at 60°C for 3 days and terminated by exposure to air.
  • DMF N,N-dimethylformamide
  • PMDETA 0.14 mmol N,N,N',N,'N"-pentamethyldiethylenetriamine
  • the reaction mixture was filtered through a neutral alumina column to remove the copper catalyst, the solution was concentrated under reduced pressure and precipitated in a 20-fold excess of a mixed solvent (methanol to water volume ratio of 1:1), the product was collected by filtration, and vacuum dried to obtain a triblock copolymer of poly(acrylic acid-acrylamide-ethyl methacrylate)-polyvinylidene fluoride-poly(acrylic acid-acrylamide-ethyl methacrylate) with a weight average molecular weight of 1.2 million, which was used as a battery binder.
  • Lithium nickel cobalt manganese (LiNi 0.8 Mn 0.1 Co 0.1 O 2 ) material, conductive agent carbon black, the binder prepared in Example 1, and N-methylpyrrolidone (NMP) were stirred and mixed in a weight ratio of 96.9:2.1:1:21 to obtain a positive electrode slurry with a solid content of 73%.
  • the positive electrode slurry was then evenly coated on a positive electrode current collector, and then dried, cold pressed, and cut to obtain a positive electrode sheet.
  • the active material artificial graphite, the conductive agent carbon black, the binder styrene-butadiene rubber (SBR), and the thickener sodium hydroxymethyl cellulose (CMC) are dissolved in the solvent deionized water in a weight ratio of 96.2:0.8:0.8:1.2, and the negative electrode slurry is prepared after being evenly mixed; the negative electrode slurry is evenly coated on the negative electrode collector copper foil once or multiple times, and the negative electrode sheet is obtained after drying, cold pressing, and slitting.
  • Polypropylene film is used as the isolation film.
  • the positive electrode sheet, the separator, and the negative electrode sheet of Example 1 are stacked in order, so that the separator is between the positive and negative electrode sheets to play an isolating role, and then wound to obtain a bare cell, and the bare cell is welded with a pole ear, and the bare cell is placed in an aluminum shell, and baked at 80°C to remove water, and then the electrolyte is injected and sealed to obtain an uncharged battery.
  • the uncharged battery is then subjected to the processes of static, hot and cold pressing, formation, shaping, and capacity testing in sequence to obtain the lithium-ion battery product of Example 1.
  • the battery of Example 2-11 is similar to the battery preparation method of Example 1, but the weight average molecular weight of the poly(acrylic acid-acrylamide-ethyl methacrylate)-polyvinylidene fluoride-poly(acrylic acid-acrylamide-ethyl methacrylate) triblock copolymer is adjusted by adjusting the polymerization reaction temperature and reaction temperature of the A-block and the B-block, respectively, adjusting the polymerization degree of the A-block and the B-block, and adjusting the weight average molecular weight of the A-block and the B-block.
  • the specific parameters are shown in Tables 1 and 3.
  • Example 12-15 The preparation methods of the batteries of Examples 12-15 are similar to those of Example 1, but the mass fractions of the binder are adjusted to 0.1% (Example 12), 0.2% (Example 13), 1.2% (Example 14), and 3% (Example 15), respectively, based on the mass of the positive electrode active material.
  • the remaining parameters are the same as those of Example 1, and the specific parameters are shown in Table 3.
  • the preparation method of the battery of Example 16 is similar to that of the battery of Example 5, except that the A-block is replaced with a polyvinyl fluoride block.
  • the specific parameters are shown in Table 3.
  • the preparation method is as follows:
  • A-block 1% of the monomer mass of 4-(chloromethyl)benzoyl peroxide was dissolved in 300ml of anhydrous acetonitrile, introduced into a high-pressure reactor and purged with N2 for 30 minutes. 3.8g of vinyl fluoride was transferred to the reactor at room temperature. The temperature inside the reactor was raised to 90°C, and the reaction mixture was stirred at 500 rpm for 4.7 hours. After the reaction was completed, the solvent was removed, and the resulting solid was washed with chloroform several times to remove the initiator residues, and vacuum dried at 45°C to obtain a white product, namely chlorine-terminated polyvinyl fluoride.
  • the preparation method of the battery of Example 17 is similar to that of the battery of Example 5, but the A-block is replaced by a polytetrafluoroethylene block.
  • the specific parameters are shown in Table 3.
  • the preparation method is as follows:
  • A-block 1% of the monomer mass of 4-(chloromethyl)benzoyl peroxide was dissolved in 300ml of anhydrous acetonitrile, introduced into a high-pressure reactor and purged with N2 for 30 minutes. 4.2g of tetrafluoroethylene was transferred to the reactor at room temperature, the internal temperature of the reactor was raised to 90°C, and the reaction mixture was stirred at 500 rpm for 4.7 hours. After the reaction was completed, the solvent was removed, and the obtained solid was washed with chloroform several times to remove the initiator residues, and vacuum dried at 45°C to obtain a white product, namely chlorine-terminated polytetrafluoroethylene.
  • the preparation method of the battery of Example 18 is similar to that of the battery of Example 5, but the B-block is replaced with poly(acrylic acid-acrylonitrile-ethyl methacrylate).
  • the specific parameters are shown in Table 3.
  • the preparation method is as follows:
  • B-block Acrylic acid, ethyl methacrylate and acrylonitrile were weighed in a molar ratio of 8:1:1, 500 ml of tetrahydrofuran was measured, added to a four-necked flask, a large amount of nitrogen was introduced, and the stirring speed was gradually increased to 1200 rpm, 1% of the monomer mass of RAFT chain transfer agent (CTA-alkyne) and 0.1% of the monomer mass of azobisisobutyronitrile were added, and the temperature was raised to 75°C. After 5 hours of reaction, the reaction was terminated by cooling in liquid nitrogen, and the solution was precipitated in excess methanol.
  • RAFT chain transfer agent CTA-alkyne
  • azobisisobutyronitrile azobisisobutyronitrile
  • the polymer was collected by filtration and reprecipitated twice from chloroform with methanol. The resulting product was vacuum dried overnight at room temperature to remove all traces of residual solvents to obtain a single-end poly (acrylic acid-acrylonitrile-ethyl methacrylate) with an alkynyl-capped weight average molecular weight of 250,000, i.e., a B-block polymer.
  • Example 19 The battery of Example 19 is prepared in a similar manner to the battery of Example 5, except that the B- The segment is replaced with poly(acrylic acid-ethyl methacrylate), the specific parameters are shown in Table 3, and the preparation method is as follows:
  • B-block Weigh acrylic acid and ethyl methacrylate in a molar ratio of 8:1, measure 500 ml of tetrahydrofuran, add to a four-necked flask, pass a large amount of nitrogen, and gradually increase the stirring speed to 1200 rpm, add 1% of the monomer mass of RAFT chain transfer agent (CTA-alkyne) and 0.1% of the monomer mass of azobisisobutyronitrile, and heat to 60°C. After 7 hours of reaction, the reaction was terminated by cooling in liquid nitrogen, and the solution was precipitated in excess methanol. The polymer was collected by filtration and reprecipitated twice from chloroform with methanol.
  • RAFT chain transfer agent CTA-alkyne
  • azobisisobutyronitrile azobisisobutyronitrile
  • the resulting product was vacuum dried overnight at room temperature to remove all traces of residual solvent to obtain a single-end poly (acrylic acid-ethyl methacrylate) with an alkynyl-capped weight average molecular weight of 250,000, i.e., a B-block polymer.
  • the preparation method of the battery of Example 20 is similar to that of the battery of Example 5, but the B-block is replaced with polyacrylic acid.
  • the specific parameters are shown in Table 3.
  • the preparation method is as follows:
  • B-block Weigh acrylic acid, measure 500 ml of tetrahydrofuran, add to a four-necked flask, pass a large amount of nitrogen, and gradually increase the stirring speed to 1200 rpm, add 1% of the monomer mass of RAFT chain transfer agent (CTA-alkyne) and 0.1% of the monomer mass of azobisisobutyronitrile, and heat to 60°C. After reacting for 7 hours, the reaction is terminated by cooling in liquid nitrogen, and the solution is precipitated in excess methanol. The polymer is collected by filtration and reprecipitated twice from chloroform with methanol.
  • RAFT chain transfer agent CTA-alkyne
  • azobisisobutyronitrile azobisisobutyronitrile
  • the resulting product is vacuum dried overnight at room temperature to remove all traces of residual solvents to obtain a single-end polyacrylic acid with an alkynyl capping having a weight average molecular weight of 250,000, i.e., a B-block polymer.
  • the preparation method of the battery of Example 21 is similar to that of the battery of Example 5, but the B-block is replaced with poly(acrylic acid-acrylonitrile).
  • the specific parameters are shown in Table 3.
  • the preparation method is as follows:
  • B-block Weigh acrylic acid and acrylonitrile at a molar ratio of 8:1, measure 500 ml of tetrahydrofuran, add them into a four-necked flask, introduce a large amount of nitrogen, gradually increase the stirring speed to 1200 rpm, add 1% of the monomer weight of RAFT chain transfer agent (CTA-alkyne) and 0.1% of the monomer weight of azobisisobutyronitrile, and heat to 60°C. After reacting for 7 hours, The reaction was terminated by cooling in liquid nitrogen, and the solution was precipitated in excess methanol. The polymer was collected by filtration and reprecipitated twice from chloroform with methanol.
  • RAFT chain transfer agent CTA-alkyne
  • azobisisobutyronitrile azobisisobutyronitrile
  • the resulting product was vacuum dried overnight at room temperature to remove all traces of residual solvent to obtain an alkynyl-capped single-end poly(acrylic acid-acrylonitrile) with a weight average molecular weight of 250,000, i.e., a B-block polymer.
  • the preparation method of the battery of Example 22 is similar to that of the battery of Example 5, but the B-block is replaced with poly(acrylic acid-acrylamide).
  • the specific parameters are shown in Table 3.
  • the preparation method is as follows:
  • B-block Weigh acrylic acid and acrylamide at a molar ratio of 8:1, measure 500 ml of tetrahydrofuran, add to a four-necked flask, pass a large amount of nitrogen, and gradually increase the stirring speed to 1200 rpm, add 1% of the monomer mass of RAFT chain transfer agent (CTA-alkyne) and 0.1% of the monomer mass of azobisisobutyronitrile, and heat to 60°C. After 7 hours of reaction, the reaction is terminated by cooling in liquid nitrogen, and the solution is precipitated in excess methanol. The polymer is collected by filtration and reprecipitated twice from chloroform with methanol.
  • RAFT chain transfer agent CTA-alkyne
  • azobisisobutyronitrile azobisisobutyronitrile
  • the resulting product is vacuum dried overnight at room temperature to remove all traces of residual solvent to obtain a poly (acrylic acid-acrylamide) with an alkynyl capping at one end with a weight average molecular weight of 250,000, i.e., a B-block polymer.
  • the preparation method of the battery of Example 23 is similar to that of the battery of Example 5, but the B-block is replaced with poly(acrylic acid-acrylonitrile-acrylamide), the specific parameters are shown in Table 3, and the preparation method is as follows:
  • B-block Weigh acrylic acid, acrylonitrile and acrylamide in a molar ratio of 8:1:1, measure 500 ml of tetrahydrofuran, add to a four-necked flask, pass a large amount of nitrogen, and gradually increase the stirring speed to 1200 rpm, add 1% of the monomer mass of RAFT chain transfer agent (CTA-alkyne) and 0.1% of the monomer mass of azobisisobutyronitrile, and heat to 75°C. After 5 hours of reaction, the reaction is terminated by cooling in liquid nitrogen, and the solution is precipitated in excess methanol. The polymer is collected by filtration and reprecipitated twice from chloroform with methanol.
  • RAFT chain transfer agent CTA-alkyne
  • azobisisobutyronitrile azobisisobutyronitrile
  • the resulting product is vacuum dried overnight at room temperature to remove all traces of residual solvent to obtain a poly (acrylic acid-acrylonitrile-acrylamide) with an alkynyl capping at one end with a weight average molecular weight of 250,000, i.e., a B-block polymer.
  • the preparation method of the battery of Example 24 is similar to that of the battery of Example 5, but the A-block is replaced with a poly(vinylidene fluoride-hexafluoropropylene) block.
  • the specific parameters are shown in Table 3.
  • the preparation method is as follows:
  • A-block 1% of the monomer mass of 4-(chloromethyl)benzoyl peroxide was dissolved in 300ml of anhydrous acetonitrile, introduced into a high-pressure reactor and purged with N2 for 30 minutes. 15g of vinylidene fluoride and 5g of hexafluoropropylene were transferred to the reactor at room temperature, the internal temperature of the reactor was raised to 90°C, and the reaction mixture was stirred at 500 rpm for 4.7 hours.
  • the polymer solution was concentrated and precipitated three times in a mixed solvent (the volume ratio of methanol to water was 1:1), and vacuum dried at 45°C to obtain azide-terminated poly(vinylidene fluoride-hexafluoropropylene), namely A-block polymer.
  • RAFT chain transfer agent CTA-alkyne
  • polymerization reaction is used to prepare acetylene-terminated polyvinylidene fluoride; wherein the structural formula of RAFT chain transfer agent is as follows
  • A-block using azide as an initiator, a polymerization reaction is performed to prepare azide-terminated poly(acrylic acid-acrylamide-ethyl methacrylate);
  • Poly(acrylic acid-acrylamide-ethyl methacrylate) having azide groups at both ends and polyvinylidene fluoride having alkynyl groups at the ends and cuprous bromide were added to a dry Schlenk tube in a molar ratio of 1:2.5:4. After degassing, 4 ml of anhydrous N,N-dimethylformamide (DMF) and 0.14 mmol N,N,N',N,'N"-pentamethyldiethylenetriamine (PMDETA) were added. The reaction was stirred at 60°C for 3 days and terminated by exposure to air.
  • DMF N,N-dimethylformamide
  • PMDETA 0.14 mmol N,N,N',N,'N"-pentamethyldiethylenetriamine
  • the reaction mixture was filtered through a neutral alumina column to remove the copper catalyst, the solution was concentrated under reduced pressure and precipitated in a 20-fold excess of a mixed solvent (the volume ratio of methanol to water was 1:1), the product was collected by filtration, and vacuum dried to obtain a polyvinylidene fluoride-poly(acrylic acid-acrylamide-ethyl methacrylate)-polyvinylidene fluoride block copolymer with a weight average molecular weight of 1.2 million, which was used as a battery binder.
  • the batteries of Examples 26-35 are prepared in a similar manner to the battery of Example 25, but The weight average molecular weight of polyvinylidene fluoride-poly(acrylic acid-acrylamide-ethyl methacrylate)-polyvinylidene fluoride was adjusted by adjusting the polymerization reaction temperature and reaction temperature of the A-block and the B-block, adjusting the polymerization degree of the A-block and the B-block, and adjusting the weight average molecular weight of the A-block and the B-block. The specific parameters are shown in Table 2.
  • Example 36-39 The preparation methods of the batteries of Examples 36-39 are similar to those of Example 25, but the mass fraction of the binder is adjusted to 0.1% (Example 36), 0.2% (Example 37), 1.2% (Example 38), and 3% (Example 39), respectively, based on the mass of the positive electrode active material.
  • the remaining parameters are the same as those of Example 25, and the specific parameters are shown in Tables 1 and 2.
  • the preparation method of the battery of Example 40 is similar to that of Example 25, but the B-block is replaced by a polyvinyl fluoride block.
  • the specific parameters are shown in Table 3.
  • the preparation method is as follows:
  • Example 41 The battery preparation method of Example 41 is similar to that of Example 25, but the B-block is replaced with a polytetrafluoroethylene block.
  • the specific parameters are shown in Table 3.
  • the preparation method is as follows:
  • the preparation method of the battery of Example 42 is similar to that of Example 25, but the B-block is replaced with a poly(vinylidene fluoride-hexafluoropropylene) block.
  • the specific parameters are shown in Table 3.
  • the preparation method is as follows:
  • Example 43 The battery preparation method of Example 43 is similar to that of Example 26, but the A-block is replaced with a polyacrylic acid block.
  • the specific parameters are shown in Table 3.
  • the preparation method is as follows:
  • the polymer was vacuum dried at 45°C to obtain a white product.
  • 3 mmol of chlorine-terminated polyacrylic acid and 60 mmol of sodium azide (NaN 3 ) were dissolved in 600 ml of N,N-dimethylformamide (DMF) and stirred at 60°C overnight.
  • the polymer solution was concentrated and precipitated three times in a mixed solvent (the volume ratio of methanol to water was 1:1).
  • the pale yellow product was then vacuum dried at 45°C to obtain a polyacrylic acid block containing azides at both ends, i.e., A-block polymer.
  • Example 44 The battery preparation method of Example 44 is similar to that of Example 26, but the A-block is replaced with a poly(acrylic acid-acrylamide) block.
  • the specific parameters are shown in Table 3.
  • the preparation method is as follows:
  • Example 45 The battery preparation method of Example 45 is similar to that of Example 26, but the A-block is replaced with a poly(acrylic acid-acrylonitrile-acrylamide) block.
  • the specific parameters are shown in Table 3.
  • the preparation method is as follows:
  • the preparation method of the battery of Comparative Example 1 is similar to that of the battery of Example 1, but the binder is polyvinylidene fluoride, the specific parameters of which are shown in Table 3, and the binder is 5130 purchased from Solvay Group.
  • the preparation method of the battery of Comparative Example 2 is similar to that of the battery of Example 1, but the binder is polyacrylic acid.
  • the specific parameters are shown in Table 3.
  • the preparation method is as follows:
  • the preparation method of the battery of Comparative Example 3 is similar to that of the battery of Example 1, but the binder is poly(acrylic acid-ethyl methacrylate), the specific parameters are shown in Table 3, and the preparation method is as follows:
  • Acrylic acid and ethyl methacrylate were weighed in a molar ratio of 8:1, 500ml of tetrahydrofuran was measured, added to a four-necked flask, a large amount of nitrogen was introduced, and the stirring speed was gradually increased to 1200 rpm, 1% of the monomer mass of RAFT chain transfer agent (CTA-alkyne) and 0.1% of the monomer mass of azobisisobutyronitrile were added, and the temperature was raised to 60°C. After reacting for 7 hours, the reaction was terminated by cooling in liquid nitrogen, and the solution was precipitated in excess methanol. The polymer was collected by filtration and reprecipitated twice from chloroform with methanol. The resulting polymer was vacuum dried overnight at room temperature to remove all traces of residual solvent to obtain the target binder.
  • RAFT chain transfer agent CTA-alkyne
  • azobisisobutyronitrile azobisisobutyronitrile
  • the preparation method of the battery of Comparative Example 4 is similar to that of the battery of Example 1, but the binder is poly(acrylic acid-acrylonitrile-ethyl methacrylate), the specific parameters are shown in Table 3, and the preparation method is as follows:
  • Acrylic acid, ethyl methacrylate and acrylonitrile were weighed in a molar ratio of 8:1:1, 500ml of tetrahydrofuran was measured, added to a four-necked flask, a large amount of nitrogen was introduced, and the stirring speed was gradually increased to 1200 rpm, 1% of the monomer mass of RAFT chain transfer agent (CTA-alkyne) and 0.1% of the monomer mass of azobisisobutyronitrile were added, and the temperature was raised to 60°C. After reacting for 7 hours, the reaction was terminated by cooling in liquid nitrogen, and the solution was precipitated in excess methanol. The polymer was collected by filtration and reprecipitated twice from chloroform with methanol. The resulting polymer was vacuum dried overnight at room temperature to remove all traces of residual solvent to obtain the target binder.
  • RAFT chain transfer agent CTA-alkyne
  • azobisisobutyronitrile azobisisobuty
  • the battery of Comparative Example 5 is prepared in a similar manner to the battery of Example 1, but the binder is poly(acrylic acid-acrylamide-ethyl methacrylate).
  • the specific parameters are shown in Table 3. Methods as below:
  • Acrylic acid, ethyl methacrylate and acrylamide were weighed in a molar ratio of 8:1:1, 500 ml of tetrahydrofuran was measured, added to a four-necked flask, a large amount of nitrogen was introduced, and the stirring speed was gradually increased to 1200 rpm, 1% of the monomer mass of RAFT chain transfer agent (CTA-alkyne) and 0.1% of the monomer mass of azobisisobutyronitrile were added, and the temperature was raised to 60 ° C. After reacting for 7 hours, the reaction was terminated by cooling in liquid nitrogen, and the solution was precipitated in excess methanol. The polymer was collected by filtration and reprecipitated twice from chloroform with methanol. The resulting polymer was vacuum dried overnight at room temperature to remove all traces of residual solvent to obtain the target binder.
  • RAFT chain transfer agent CTA-alkyne
  • azobisisobutyronitrile azobisisobuty
  • the preparation method of the battery of Comparative Example 6 is similar to that of the battery of Example 1, but the binder is a blend of polyvinylidene fluoride and poly(acrylic acid-acrylamide-ethyl methacrylate), the specific parameters are shown in Table 3, and the preparation method is as follows:
  • Blending The poly(acrylic acid-acrylamide-ethyl methacrylate) in Comparative Example 5 and the polyvinylidene fluoride in Comparative Example 1 are blended in a molar ratio of 6:4 to obtain a blend adhesive of polyvinylidene fluoride and poly(acrylic acid-acrylamide-ethyl methacrylate).
  • the preparation method of the battery of Comparative Example 7 is similar to that of the battery of Example 1, but the binder is a blend of polyvinylidene fluoride and polyacrylic acid.
  • the specific parameters are shown in Table 3.
  • the preparation method is as follows:
  • Blending The polyacrylic acid in Comparative Example 2 and the polyvinylidene fluoride in Comparative Example 1 are blended in a molar ratio of 6:4 to obtain a blend adhesive of polyvinylidene fluoride and polyacrylic acid.
  • test After re-stirring the slurry for 30 minutes, take a certain amount of slurry and pour it into the sample bottle of the stability instrument. After putting it into the sample bottle, close the test tower cover, open the test tower cover, and a scanning curve will begin to appear on the test interface, and the sample stability test will begin. The test will be completed after more than 48 hours of continuous testing.
  • the positive electrode sheet was cut into a test sample of 20mm ⁇ 100mm size for standby use; the sheet was bonded to one side of the positive electrode film layer with double-sided tape, and compacted with a roller to make the double-sided tape and the sheet completely fit; the other side of the double-sided tape was pasted to the stainless steel surface, and one end of the sample was bent in the opposite direction with a bending angle of 180°; the high-speed rail tensile machine was used for testing, one end of the stainless steel was fixed to the lower fixture of the tensile machine, and the bent end of the sample was fixed to the upper fixture, and the angle of the sample was adjusted to ensure that the upper and lower ends were in a vertical position, and then the sample was stretched at a speed of 50mm/min until the current collector was completely peeled off from the positive electrode film, and the displacement and force during the process were recorded.
  • the force at the time of force balance divided by the width of the sheet bonded to the double-sided tape (the width direction of the sheet is perpendicular to the peeling direction) is taken as the bonding force of the sheet per unit length.
  • the width of the sheet bonded to the double-sided tape is 20mm.
  • the cold-pressed positive electrode sheet is cut into test specimens of 20mm ⁇ 100mm size; after folding it in the forward direction, it is flattened with a 2kg roller, and unfolded to check whether there is light transmittance through the gap. If there is no light transmittance, fold it in the reverse direction, flatten it with a 2kg roller, and check again against the light. Repeat this process until light transmittance appears in the gap, and record the number of folding times; repeat the test three times, and take the average value as the reference data for the flexibility of the electrode sheet.
  • the battery capacity retention rate data corresponding to the embodiment or comparative example in Table 4 is the data measured after 500 cycles under the above test conditions, that is, the value of P500.
  • the test process of the comparative example and other embodiments is the same as above.
  • the battery DC impedance test process is as follows: at 25°C, charge the battery at a constant current of 1/3C to 4.3V, then charge at a constant voltage of 4.3V to a current of 0.05C, leave it for 5 minutes, and record the voltage V1. Then discharge it at 1/3C for 30s, record the voltage V2, and then (V2-V1)/(1/3C) is the internal resistance DCR1 of the battery after the first cycle.
  • the battery internal resistance increase ratio of Example 1 in Table 4 (DCRn-DCR1)/DCR1 ⁇ 100%, and the test process of the comparative example and other examples is the same as above.
  • the data in Table 4 are measured after 100 cycles under the above test conditions.
  • a Waters 2695 Isocratic HPLC gel chromatograph (differential refractive index detector 2141) was used.
  • a polystyrene solution sample with a mass fraction of 3.0% was used as a reference, and a matching chromatographic column (oily: Styragel HT5 DMF7.8*300mm+Styragel HT4) was selected.
  • a 3.0% polymer gel solution was prepared with purified N-methylpyrrolidone (NMP) solvent, and the prepared solution was allowed to stand for one day for use.
  • NMP N-methylpyrrolidone
  • tetrahydrofuran was first drawn with a syringe, rinsed, and repeated several times. Then 5 ml of the experimental solution was drawn, the air in the syringe was removed, and the needle tip was wiped dry. Finally, the sample solution was slowly injected into the injection port. Data was obtained after the indication was stable.
  • the binders in Examples 1-45 all contain polymers, and the polymers all contain A-blocks and B-blocks, wherein the A-blocks of Examples 1-24 contain structural units derived from monomers shown in Formula I, and the B-blocks contain structural units derived from monomers shown in Formula II or structural units derived from monomers shown in Formula II and structural units derived from monomers shown in Formula III.
  • the A blocks of Examples 25-45 contain structural units derived from monomers shown in Formula II or structural units derived from monomers shown in Formula II and structural units derived from monomers shown in Formula III, and the B blocks contain structural units derived from monomers shown in Formula I.
  • the binder can effectively slow down the gelation of the slurry, improve the stability of the slurry, improve the flexibility of the pole piece, improve the bonding force, reduce the membrane resistance, reduce the DC impedance growth rate of the battery, and/or improve the cycle capacity retention rate of the battery.
  • the monomer represented by formula II in the B block is selected from one or more of acrylic acid, methacrylic acid, and ethacrylic acid
  • the monomer represented by formula III in the B block is selected from one or more of acrylamide, acrylate, and acrylonitrile.
  • the B block is selected from one or more of poly(acrylic acid-acrylamide-ethyl methacrylate), poly(acrylic acid-acrylonitrile-ethyl methacrylate), polyacrylic acid, poly(acrylic acid-ethyl methacrylate), poly(acrylic acid-acrylonitrile), poly(acrylic acid-acrylamide), and poly(acrylic acid-acrylonitrile-acrylamide), the gel phenomenon of the slurry can be effectively slowed down, the stability of the slurry can be improved, the flexibility of the electrode sheet can be improved, the membrane resistance can be reduced, and the cycle capacity retention rate of the battery can be improved.
  • the gelation phenomenon of the slurry can be effectively slowed down, the stability of the slurry can be improved, the flexibility of the electrode sheet can be improved, the bonding force can be improved, the membrane resistance can be reduced, the DC impedance growth rate of the battery can be reduced, and the cycle capacity retention rate of the battery can be improved.
  • the monomer represented by Formula II in the A-block is selected from one or more of acrylic acid, methacrylic acid, and ethacrylic acid
  • the monomer represented by Formula III in the A-block is selected from one or more of acrylamide, acrylate, and acrylonitrile.
  • the monomer represented by Formula III in the A-block is selected from one or more of acrylamide, ethyl methacrylate, and acrylonitrile
  • the A-block is selected from one or more of poly(acrylic acid-acrylamide-ethyl methacrylate), polyacrylic acid, poly(acrylic acid-acrylamide), and poly(acrylic acid-acrylonitrile-acrylamide)
  • it can effectively slow down the gelation of the slurry, improve the stability of the slurry, reduce the membrane resistance, and reduce the DC impedance growth rate of the battery.
  • the block copolymers are polyacrylic acid-polyvinylidene fluoride-polyacrylic acid triblock copolymer, poly(acrylic acid-ethyl methacrylate)-polyvinylidene fluoride-poly(acrylic acid-ethyl methacrylate) triblock copolymer, poly(acrylic acid-acrylonitrile-ethyl methacrylate)-polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-ethyl methacrylate) triblock copolymer, poly(acrylic acid-acrylamide-ethyl methacrylate)-polyvinylidene fluoride-poly(acrylic acid-acrylamide-ethyl methacrylate) triblock copolymers of poly(acrylic acid-acrylamide-ethyl methacrylate)-polyvinyl fluoride-poly(acrylic acid-acrylamide-ethyl methacrylate) triblock copolymers
  • the block copolymer is a triblock copolymer of poly(acrylic acid-acrylamide-ethyl methacrylate)-polyvinyl fluoride-poly(acrylic acid-acrylamide-ethyl methacrylate), a triblock copolymer of poly(acrylic acid-acrylamide-ethyl methacrylate)-polytetrafluoroethylene-poly(acrylic acid-acrylamide-ethyl methacrylate), and a triblock copolymer of poly(acrylic acid-acrylamide-acrylate)-poly(vinylidene fluoride-hexafluoropropylene)-poly(acrylic acid-acrylamide-ethyl methacrylate), the adhesion can be improved, and the cycle capacity retention rate of the battery can be improved.
  • Example 18 From the comparison of Example 18 with Comparative Examples 1 and 4, it can be seen that when the block copolymer is a triblock copolymer of poly(acrylic acid-acrylonitrile-ethyl methacrylate)-polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-ethyl methacrylate), the adhesion can be improved, the DC impedance growth rate of the battery can be reduced, and the cycle capacity retention rate of the battery can be improved.
  • Example 19 From the comparison between Example 19 and Comparative Examples 1 and 3, it can be seen that when the block copolymer is a triblock copolymer of poly(acrylic acid-ethyl methacrylate)-polyvinylidene fluoride-poly(acrylic acid-ethyl methacrylate), the flexibility of the pole piece can be improved, the DC impedance growth rate of the battery can be reduced, and the cycle capacity retention rate of the battery can be improved.
  • Example 20 From the comparison between Example 20 and Comparative Examples 1-2 and 7, it can be seen that when the block copolymer is a triblock copolymer of polyacrylic acid-polyvinylidene fluoride-polyacrylic acid, the bonding force can be improved and the cycle capacity retention rate of the battery can be improved.
  • the block copolymer is a triblock copolymer of polyvinylidene fluoride-poly(acrylic acid-acrylamide-ethyl methacrylate)-polyvinylidene fluoride, polyvinyl fluoride-poly(acrylic acid-acrylamide-ethyl methacrylate)- One or more of the following: polyvinyl fluoride triblock copolymer, polytetrafluoroethylene-poly(acrylic acid-acrylamide-ethyl methacrylate)-polytetrafluoroethylene triblock copolymer, poly(vinylidene fluoride-hexafluoropropylene)-poly(acrylic acid-acrylamide-ethyl methacrylate)-poly(vinylidene fluoride-hexafluoropropylene) triblock copolymer, polyvinylidene fluoride-
  • block copolymer is a triblock copolymer of polyvinyl fluoride-poly(acrylic acid-acrylamide-ethyl methacrylate)-polyvinyl fluoride, polytetrafluoroethylene-poly(acrylic acid-acrylamide-ethyl methacrylate)-polytetrafluoroethylene, poly(vinylidene fluoride-hexafluoropropylene)-poly(acrylic acid-acrylamide-ethyl methacrylate)-poly(vinylidene fluoride-hexafluoropropylene), it can reduce the membrane resistance, improve the bonding force, and reduce the DC impedance growth rate of the battery.
  • Example 43 From the comparison between Example 43 and Comparative Examples 1-2 and 7, it can be seen that when the block copolymer is a triblock copolymer of polyvinylidene fluoride-polyacrylic acid-polyvinylidene fluoride, it can reduce the membrane resistance, improve the adhesion, reduce the DC impedance growth rate of the battery, and improve the battery's cycle capacity retention rate.

Abstract

The present application relates to a BAB-type block copolymer, a preparation method, a binder, a positive pole piece, a secondary battery, and an electrical apparatus. In particular, the present application provides a BAB-type block copolymer, which comprises an A-block and a B-block. The A-block comprises a structural unit derived from a monomer represented by formula I, and the B-block comprises a structural unit derived from a monomer represented by formula II; or the A-block comprises a structural unit derived from a monomer represented by formula II, and the B-block comprises a structural unit derived from a monomer represented by I. The binder prepared from the BAB-type block copolymer can effectively slow down the gelatinization of a slurry, improve the stability of the slurry, improve the flexibility of the pole piece, improve the bonding force, reduce the resistance of a diaphragm, reduce the direct-current impedance growth rate of the battery, and/or improve the cycle capacity retention rate of the battery.

Description

BAB型嵌段共聚物、制备方法、粘结剂、正极极片、二次电池及用电装置BAB type block copolymer, preparation method, binder, positive electrode sheet, secondary battery and electrical device
交叉引用cross reference
本申请引用于2022年9月30日递交的名称为“BAB型嵌段共聚物、制备方法、粘结剂、正极极片、二次电池及用电装置”的第202211206844.2号中国专利申请以及于2022年10月27日递交的名称为“BAB型嵌段共聚物、制备方法、正极极片、二次电池、电池模板、电池包及用电装置”的第PCT/CN2022/128035号专利申请，其通过引用被全部并入本申请。This application refers to Chinese Patent Application No. 202211206844.2 filed on September 30, 2022, entitled “BAB-type block copolymer, preparation method, binder, positive electrode sheet, secondary battery and electrical device” and Patent Application No. PCT/CN2022/128035 filed on October 27, 2022, entitled “BAB-type block copolymer, preparation method, positive electrode sheet, secondary battery, battery template, battery pack and electrical device”, which are all incorporated into this application by reference.
技术领域Technical Field
本申请涉及二次电池技术领域，尤其涉及一种BAB型嵌段共聚物、制备方法、粘结剂、正极极片、二次电池和用电装置。The present application relates to the technical field of secondary batteries, and in particular to a BAB-type block copolymer, a preparation method, a binder, a positive electrode sheet, a secondary battery and an electrical device.
背景技术Background technique
近年来，二次电池广泛应用于水力、火力、风力和太阳能电站等储能电源***，以及电动工具、电动自行车、电动摩托车、电动汽车、军事装备、航空航天等多个领域。In recent years, secondary batteries have been widely used in energy storage power systems such as hydropower, thermal, wind and solar power stations, as well as in power tools, electric bicycles, electric motorcycles, electric vehicles, military equipment, aerospace and other fields.
粘结剂是二次电池中的常用材料，广泛应用于电池极片、隔离膜、封装处等。但是传统的粘结剂生产成本高、产能不足，对环境危害大，且在制备过程中容易出现凝胶，导致浆料稳定性差、加工成本高，以其制备的极片柔性差、粘结力低、电阻高、良品率低，电池的直流阻抗增长率高、循环容量保持率低、性能不稳定，难以满足市场对于电池成本和性能的要求。因此，现有的粘结剂仍有待改进。Binders are commonly used materials in secondary batteries and are widely used in battery pole pieces, separators, packaging, etc. However, traditional binders have high production costs, insufficient production capacity, great environmental hazards, and are prone to gelation during the preparation process, resulting in poor slurry stability and high processing costs. The pole pieces prepared with them have poor flexibility, low adhesion, high resistance, and low yield. The battery has a high DC impedance growth rate, low cycle capacity retention rate, and unstable performance, which makes it difficult to meet the market's requirements for battery cost and performance. Therefore, existing binders still need to be improved.
发明内容Summary of the invention
本申请是鉴于上述课题而进行的，其目的在于，提供一种BAB 型嵌段共聚物，以BAB型嵌段共聚物制备的粘结剂能够有效减缓浆料的凝胶现象，提高浆料的稳定性，提高极片的柔性，提高粘结力，降低膜片电阻，降低电池的直流阻抗增长率，和/或提高电池的循环容量保持率。The present application is made in view of the above-mentioned problems, and its purpose is to provide a BAB The binder prepared with the BAB type block copolymer can effectively slow down the gelation phenomenon of the slurry, improve the stability of the slurry, improve the flexibility of the pole piece, improve the bonding force, reduce the membrane resistance, reduce the DC impedance growth rate of the battery, and/or improve the cycle capacity retention rate of the battery.
本申请的第一方面提供了一种BAB型嵌段共聚物，其特征在于，包含A-嵌段和B-嵌段，所述A-嵌段含有衍生自式I所示单体的结构单元，所述B-嵌段含有衍生自式II所示单体的结构单元；The first aspect of the present application provides a BAB type block copolymer, characterized in that it comprises an A-block and a B-block, wherein the A-block contains a structural unit derived from a monomer represented by formula I, and the B-block contains a structural unit derived from a monomer represented by formula II;
或者所述A-嵌段含有衍生自式II所示单体的结构单元，所述B-嵌段含有衍生自I所示单体的结构单元，
Alternatively, the A-block contains structural units derived from the monomers of formula II, and the B-block contains structural units derived from the monomers of formula I,
其中R1、R2、R3各自独立地选自氢、氟、至少含有一个氟原子的C1-3烷基中的一种或多种，R4、R5、R6各自独立地选自氢、取代或未取代的C1-5烷基。R 1 , R 2 , and R 3 are each independently selected from one or more of hydrogen, fluorine, and C 1-3 alkyl containing at least one fluorine atom; and R 4 , R 5 , and R 6 are each independently selected from hydrogen, and substituted or unsubstituted C 1-5 alkyl.
以BAB型嵌段共聚物制备的粘结剂，可以将含氟嵌段和非氟嵌段的重均分子量最大化，充分发挥含氟粘结剂和非氟粘结剂各自的优势，实现优势互补的作用。该粘结剂能够有效减缓浆料的凝胶现象，提高浆料的稳定性，提高极片的柔性，提高粘结力，降低膜片电阻，降低电池的直流阻抗增长率，和/或提高电池的循环容量保持率。The binder prepared with the BAB type block copolymer can maximize the weight average molecular weight of the fluorine-containing block and the non-fluorine block, give full play to the respective advantages of the fluorine-containing binder and the non-fluorine binder, and achieve the role of complementary advantages. The binder can effectively slow down the gelation phenomenon of the slurry, improve the stability of the slurry, improve the flexibility of the pole piece, improve the bonding force, reduce the membrane resistance, reduce the DC impedance growth rate of the battery, and/or improve the cycle capacity retention rate of the battery.
在任意实施方式中，所述B-嵌段还含有衍生自式III所示单体的结构单元；或者所述A-嵌段还包含衍生自式III所示单体的结构单元，
In any embodiment, the B-block further comprises a structural unit derived from a monomer of formula III; or the A-block further comprises a structural unit derived from a monomer of formula III,
其中R7、R8、R9各自独立地选自氢、取代或未取代的C1-5烷基，R10选自酯基、氰基、酰胺基中的一种。R 7 , R 8 and R 9 are each independently selected from hydrogen, substituted or unsubstituted C 1-5 alkyl, and R 10 is selected from one of ester group, cyano group and amide group.
在任意实施方式中，基于所述嵌段共聚物中所有结构单元的总摩尔数计，所述衍生自式I所示单体的结构单元的摩尔含量为30％-70％，可选为40％-60％。In any embodiment, based on the total molar number of all structural units in the block copolymer, the molar content of the structural unit derived from the monomer represented by formula I is 30%-70%, and optionally 40%-60%.
控制衍生自式I所示单体的结构单元的摩尔含量在合适范围内，能够有效减缓浆料的凝胶现象，提高浆料的稳定性，提高极片的柔性，降低膜片电阻，并提高电池的循环容量保持率。Controlling the molar content of the structural unit derived from the monomer represented by Formula I within a suitable range can effectively slow down the gelation of the slurry, improve the stability of the slurry, increase the flexibility of the pole piece, reduce the membrane resistance, and improve the cycle capacity retention rate of the battery.
在任意实施方式中，所述嵌段共聚物的重均分子量为40万-200万，所述嵌段共聚物的重均分子量可选为120万-200万，所述嵌段共聚物的重均分子量可选为120万-150万。In any embodiment, the weight average molecular weight of the block copolymer is 400,000-2,000,000, the weight average molecular weight of the block copolymer can be selected to be 1.2 million-2,000,000, and the weight average molecular weight of the block copolymer can be selected to be 1.2 million-1.5 million.
控制嵌段共聚物的重均分子量在合适范围内，能够有效减缓浆料的凝胶现象，提高浆料的稳定性，提高极片的柔性，提高粘结力，降低膜片电阻，降低电池的直流阻抗增长率，并提高电池的循环容量保持率。Controlling the weight-average molecular weight of the block copolymer within an appropriate range can effectively slow down the gelation of the slurry, improve the stability of the slurry, increase the flexibility of the pole piece, increase the bonding force, reduce the membrane resistance, reduce the DC impedance growth rate of the battery, and improve the cycle capacity retention rate of the battery.
在任意实施方式中，所述嵌段共聚物中，所述A-嵌段的重均分子量为20万-105万。In any embodiment, in the block copolymer, the weight average molecular weight of the A-block is 200,000 to 1,050,000.
控制嵌段共聚物中A-嵌段的重均分子量在合适范围内，能够有效减缓浆料的凝胶现象，提高浆料的稳定性，提高极片的柔性，降低膜片电阻，并提高电池的循环容量保持率。Controlling the weight average molecular weight of the A-block in the block copolymer within a suitable range can effectively slow down the gelation of the slurry, improve the stability of the slurry, increase the flexibility of the pole piece, reduce the membrane resistance, and improve the cycle capacity retention rate of the battery.
在任意实施方式中，所述嵌段共聚物中，每个B-嵌段的重均分子量为10万-50万。In any embodiment, in the block copolymer, the weight average molecular weight of each B-block is 100,000 to 500,000.
控制嵌段共聚物中每个B-嵌段的重均分子量在合适范围内，能够提高粘结力，并提高电池的循环容量保持率。Controlling the weight average molecular weight of each B-block in the block copolymer within a suitable range can improve the bonding force and increase the cycle capacity retention rate of the battery.
在任意实施方式中，所述式I所示的单体选自偏氟乙烯、四氟乙烯、氟乙烯、六氟丙烯中的一种或多种。此时，能够提高粘结力，并提高电池的循环容量保持率。In any embodiment, the monomer represented by formula I is selected from one or more of vinylidene fluoride, tetrafluoroethylene, vinyl fluoride, and hexafluoropropylene. In this case, the bonding force can be improved, and the cycle capacity retention rate of the battery can be improved.
在任意实施方式中，所述式II所示单体选自丙烯酸、甲基丙烯 酸、乙基丙烯酸中的一种或多种。In any embodiment, the monomer represented by formula II is selected from acrylic acid, methacrylic acid, One or more of acrylic acid, ethacrylic acid.
在任意实施方式中，所述式III所示单体选自丙烯酰胺、丙烯酸酯、丙烯腈中的一种或多种。In any embodiment, the monomer represented by formula III is selected from one or more of acrylamide, acrylate, and acrylonitrile.
此时，能够有效减缓浆料的凝胶现象，提高浆料的稳定性，提高极片的柔性，降低膜片电阻，并提高电池的循环容量保持率。At this time, the gelation phenomenon of the slurry can be effectively slowed down, the stability of the slurry can be improved, the flexibility of the electrode can be improved, the membrane resistance can be reduced, and the cycle capacity retention rate of the battery can be improved.
上述原材料简单易得，相比于传统粘结剂能够大幅度降低生产成本，提高产量。The above raw materials are simple and easy to obtain, and compared with traditional adhesives, they can significantly reduce production costs and increase output.
在任意实施方式中，所述嵌段共聚物为聚丙烯酸-聚偏二氟乙烯-聚丙烯酸三嵌段共聚物、聚丙烯酸-聚氟乙烯-聚丙烯酸三嵌段共聚物、聚丙烯酸-聚四氟乙烯-聚丙烯酸三嵌段共聚物、聚(丙烯酸-丙烯酸酯)-聚偏二氟乙烯-聚(丙烯酸-丙烯酸酯)三嵌段共聚物、聚(丙烯酸-丙烯酸酯)-聚氟乙烯-聚(丙烯酸-丙烯酸酯)三嵌段共聚物、聚(丙烯酸-丙烯酸酯)-聚四氟乙烯-聚(丙烯酸-丙烯酸酯)三嵌段共聚物、聚(丙烯酸-丙烯腈-丙烯酸酯)-聚偏二氟乙烯-聚(丙烯酸-丙烯腈-丙烯酸酯)三嵌段共聚物、聚(丙烯酸-丙烯腈-丙烯酸酯)-聚氟乙烯-聚(丙烯酸-丙烯腈-丙烯酸酯)三嵌段共聚物、聚(丙烯酸-丙烯腈-丙烯酸酯)-聚四氟乙烯-聚(丙烯酸-丙烯腈-丙烯酸酯)三嵌段共聚物、聚(丙烯酸-丙烯酰胺-丙烯酸酯)-聚偏二氟乙烯-聚(丙烯酸-丙烯酰胺-丙烯酸酯)三嵌段共聚物、聚(丙烯酸-丙烯酰胺-丙烯酸酯)-聚氟乙烯-聚(丙烯酸-丙烯酰胺-丙烯酸酯)三嵌段共聚物、聚(丙烯酸-丙烯酰胺-丙烯酸酯)-聚四氟乙烯-聚(丙烯酸-丙烯酰胺-丙烯酸酯)三嵌段共聚物、聚(丙烯酸-丙烯腈)-聚偏二氟乙烯-聚(丙烯酸-丙烯腈)三嵌段共聚物、聚(丙烯酸-丙烯腈-丙烯酰胺)-聚偏二氟乙烯-聚(丙烯酸-丙烯腈-丙烯酰胺)三嵌段共聚物、聚(丙烯酸-丙烯腈-丙烯酸酯)-聚偏二氟乙烯-聚(丙烯酸-丙烯腈-丙烯酸酯)三嵌段共聚物、聚(丙烯酸-丙烯酰胺)-聚偏二氟乙烯-聚(丙烯酸-丙烯酰胺)三嵌段共聚物、聚(丙烯酸-丙烯腈-丙烯酰胺)-聚偏二氟乙烯-聚(丙烯酸-丙烯腈-丙烯酰胺)三嵌段共聚物、聚(偏二氟乙烯-六氟丙烯)-聚(丙烯酸-丙烯酰胺-丙烯酸酯)-聚(偏二氟乙烯-六氟丙烯) 三嵌段共聚物、聚氟乙烯-聚丙烯酸-聚氟乙烯、聚四氟乙烯-聚丙烯酸-聚四氟乙烯三嵌段共聚物、聚偏二氟乙烯-聚(丙烯酸-丙烯酸酯)-聚偏二氟乙烯三嵌段共聚物、聚氟乙烯-聚(丙烯酸-丙烯酸酯)-聚氟乙烯三嵌段共聚物、聚四氟乙烯-聚(丙烯酸-丙烯酸酯)-聚四氟乙烯三嵌段共聚物、聚偏二氟乙烯-聚(丙烯酸-丙烯腈-丙烯酸酯)-聚偏二氟乙烯三嵌段共聚物、聚氟乙烯-聚(丙烯酸-丙烯腈-丙烯酸酯)-聚氟乙烯三嵌段共聚物、聚四氟乙烯-聚(丙烯酸-丙烯腈-丙烯酸酯)-聚四氟乙烯三嵌段共聚物、聚偏二氟乙烯-聚(丙烯酸-丙烯酰胺-丙烯酸酯)-聚偏二氟乙烯三嵌段共聚物、聚氟乙烯-聚(丙烯酸-丙烯酰胺-丙烯酸酯)-聚氟乙烯三嵌段共聚物、聚四氟乙烯-聚(丙烯酸-丙烯酰胺-丙烯酸酯)-聚四氟乙烯三嵌段共聚物、聚偏二氟乙烯-聚(丙烯酸-丙烯腈)-聚偏二氟乙烯三嵌段共聚物、聚偏二氟乙烯-聚(丙烯酸-丙烯腈-丙烯酰胺)-聚偏二氟乙烯三嵌段共聚物、聚偏二氟乙烯-聚(丙烯酸-丙烯腈-丙烯酸酯)-聚偏二氟乙烯三嵌段共聚物、聚偏二氟乙烯-聚(丙烯酸-丙烯酰胺)-聚偏二氟乙烯三嵌段共聚物、聚偏二氟乙烯-聚(丙烯酸-丙烯腈-丙烯酰胺)-聚偏二氟乙烯三嵌段共聚物、聚(偏二氟乙烯-六氟丙烯)-聚(丙烯酸-丙烯酰胺-丙烯酸酯)-聚(偏二氟乙烯-六氟丙烯)三嵌段共聚物中的一种或多种。此时，能够提高电池的循环容量保持率。In any embodiment, the block copolymer is a polyacrylic acid-polyvinylidene fluoride-polyacrylic acid triblock copolymer, a polyacrylic acid-polyvinyl fluoride-polyacrylic acid triblock copolymer, a polyacrylic acid-polytetrafluoroethylene-polyacrylic acid triblock copolymer, a poly(acrylic acid-acrylate)-polyvinylidene fluoride-poly(acrylic acid-acrylate) triblock copolymer, a poly(acrylic acid-acrylate)-polyvinyl fluoride-poly(acrylic acid-acrylate) triblock copolymer, a poly(acrylic acid-acrylate)-polyvinyl fluoride-poly(acrylic acid-acrylate) triblock copolymer, a poly(acrylic acid-acrylate)-polytetrafluoroethylene-poly(acrylic acid-acrylate) triblock copolymer, a poly(acrylic acid-acrylonitrile-acrylate)-polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylate) triblock copolymer, a poly(acrylic acid-acrylonitrile-acrylate)-polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylate) triblock copolymer, a poly(acrylic acid-acrylamide-acrylate)-polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylate) triblock copolymer triblock copolymers of poly(acrylic acid-acrylamide-acrylate) and polyvinyl fluoride-poly(acrylic acid-acrylamide-acrylate) triblock copolymers, poly(acrylic acid-acrylamide-acrylate)-polytetrafluoroethylene-poly(acrylic acid-acrylamide-acrylate) triblock copolymers, poly(acrylic acid-acrylonitrile)-polyvinylidene fluoride-poly(acrylic acid-acrylonitrile) triblock copolymers, poly(acrylic acid-acrylonitrile-acrylamide)-polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylamide) Triblock copolymer, poly(acrylic acid-acrylonitrile-acrylate)-polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylate) triblock copolymer, poly(acrylic acid-acrylamide)-polyvinylidene fluoride-poly(acrylic acid-acrylamide) triblock copolymer, poly(acrylic acid-acrylonitrile-acrylamide)-polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylamide) triblock copolymer, poly(vinylidene fluoride-hexafluoropropylene)-poly(acrylic acid-acrylamide-acrylate)-poly(vinylidene fluoride-hexafluoropropylene) triblock copolymer, polyvinyl fluoride-polyacrylic acid-polyvinyl fluoride, polytetrafluoroethylene-polyacrylic acid-polytetrafluoroethylene triblock copolymer, polyvinylidene fluoride-poly(acrylic acid-acrylate)-polyvinylidene fluoride triblock copolymer, polyvinyl fluoride-poly(acrylic acid-acrylate)-polyvinylidene fluoride triblock copolymer, polytetrafluoroethylene-poly(acrylic acid-acrylate)-polytetrafluoroethylene triblock copolymer, polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylate)-polyvinylidene fluoride triblock copolymer, polyvinyl fluoride-poly(acrylic acid-acrylonitrile-acrylate)-polyvinylidene fluoride triblock copolymer, polytetrafluoroethylene-poly(acrylic acid-acrylonitrile-acrylate)-polyvinylidene fluoride triblock copolymer, polytetrafluoroethylene-poly(acrylic acid-acrylamide-acrylate)-polyvinylidene fluoride triblock copolymer, polyvinyl fluoride-poly(acrylic acid- The present invention relates to a kind of fluorocarbon-containing battery, wherein the present invention comprises one or more of the following: a polyacrylamide-acrylate)-polyvinyl fluoride triblock copolymer, a polytetrafluoroethylene-poly(acrylic acid-acrylamide-acrylate)-polytetrafluoroethylene triblock copolymer, a polyvinylidene fluoride-poly(acrylic acid-acrylonitrile)-polyvinylidene fluoride triblock copolymer, a polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylamide)-polyvinylidene fluoride triblock copolymer, a polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylate)-polyvinylidene fluoride triblock copolymer, a polyvinylidene fluoride-poly(acrylic acid-acrylamide)-polyvinylidene fluoride triblock copolymer, a polyvinylidene fluoride-poly(acrylic acid-acrylamide-polyvinylidene fluoride triblock copolymer, a polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylamide)-polyvinylidene fluoride triblock copolymer, and a poly(vinylidene fluoride-hexafluoropropylene)-poly(acrylic acid-acrylamide-acrylate)-poly(vinylidene fluoride-hexafluoropropylene) triblock copolymer. At this time, the cycle capacity retention rate of the battery can be improved.
本申请的第二方面还提供一种BAB型嵌段共聚物的制备方法，其特征在于，包括以下步骤：The second aspect of the present application also provides a method for preparing a BAB type block copolymer, characterized in that it comprises the following steps:
制备A-嵌段：将至少一种式I所示的单体聚合制备A-嵌段；Preparing the A-block: polymerizing at least one monomer represented by formula I to prepare the A-block;
或者将单体单元聚合制备A-嵌段，所述单体单元包括至少一种式II所示的单体，
Alternatively, the A-block is prepared by polymerizing monomer units, wherein the monomer units include at least one monomer represented by formula II,
其中R1、R2、R3各自独立地选自氢、氟、至少含有一个氟原子的C1-3烷基中的一种或多种，R4、R5、R6各自独立地选自氢、取代或未 取代的C1-5烷基；wherein R 1 , R 2 , and R 3 are each independently selected from one or more of hydrogen, fluorine, and a C 1-3 alkyl group containing at least one fluorine atom; and R 4 , R 5 , and R 6 are each independently selected from one or more of hydrogen, substituted or unsubstituted Substituted C 1-5 alkyl;
制备B-嵌段：将单体单元聚合制备B-嵌段，所述单体单元包括至少一种式II所示的单体，Preparation of B-block: polymerizing monomer units to prepare B-block, wherein the monomer units include at least one monomer represented by formula II,
或者将至少一种式I所示的单体聚合制备B-嵌段；Alternatively, at least one monomer of formula I is polymerized to prepare a B-block;
制备BAB型嵌段共聚物：将所述A-嵌段和所述B-嵌段接合制备BAB型嵌段共聚物，其中所述A-嵌段和所述B-嵌段含有不同的结构单元。Preparation of a BAB type block copolymer: The A-block and the B-block are joined to prepare a BAB type block copolymer, wherein the A-block and the B-block contain different structural units.
该制备方法相对于传统的共聚方法可以将含氟嵌段和非氟嵌段的重均分子量最大化，充分发挥含氟粘结剂和非氟粘结剂各自的优势，实现优势互补的作用。该方法制备的BAB型三嵌段共聚物的粘结剂能够有效减缓浆料的凝胶现象，提高浆料的稳定性，提高极片的柔性，提高粘结力，降低膜片电阻，降低电池的直流阻抗增长率，和/或提高电池的循环容量保持率。Compared with the traditional copolymerization method, this preparation method can maximize the weight average molecular weight of the fluorine-containing block and the non-fluorine block, give full play to the advantages of the fluorine-containing binder and the non-fluorine binder, and achieve the role of complementary advantages. The binder of the BAB-type triblock copolymer prepared by this method can effectively slow down the gelation phenomenon of the slurry, improve the stability of the slurry, improve the flexibility of the pole piece, improve the bonding force, reduce the membrane resistance, reduce the DC impedance growth rate of the battery, and/or improve the cycle capacity retention rate of the battery.
在任意实施方式中，所述单体单元还包括至少一种式III所示的单体，
In any embodiment, the monomer unit further comprises at least one monomer represented by formula III,
其中R7、R8、R9各自独立地选自氢、取代或未取代的C1-5烷基，R10选自酯基、氰基、酰胺基中的一种。R 7 , R 8 and R 9 are each independently selected from hydrogen, substituted or unsubstituted C 1-5 alkyl, and R 10 is selected from one of ester group, cyano group and amide group.
在任意实施方式中，所述制备B-嵌段的方法包括：In any embodiment, the method for preparing the B-block comprises:
将至少一种式I所示的单体或所述单体单元、链转移剂和第一引发剂在60-80℃的反应温度下通过可逆加成-裂解链转移聚合，反应4.5-7小时，得到末端具有炔基或叠氮基团作为端基的所述B-嵌段。At least one monomer or monomer unit represented by formula I, a chain transfer agent and a first initiator are subjected to reversible addition-fragmentation chain transfer polymerization at a reaction temperature of 60-80° C. for 4.5-7 hours to obtain the B-block having an alkynyl group or an azide group as an end group.
采用该制备方法，可实现可控聚合，且产物分子量分布较窄。By adopting the preparation method, controllable polymerization can be achieved, and the molecular weight distribution of the product is relatively narrow.
在任意实施方式中，所述制备A-嵌段的方法包括：In any embodiment, the method for preparing the A-block comprises:
将至少一种式I所示单体或所述单体单元、第二引发剂在80-95℃的反应温度下聚合反应2.5-5小时，对产物的端基进行取代反应，制 备两端均具有叠氮基团或炔基作为端基的所述A-嵌段。At least one monomer or monomer unit of Formula I and a second initiator are polymerized at a reaction temperature of 80-95° C. for 2.5-5 hours, and the end groups of the products are substituted to prepare The A-block has an azide group or an alkynyl group as a terminal group at both ends.
采用该制备方法，成功制备出末端叠氮化或末端炔基化的A-嵌段。Using this preparation method, the terminal azidated or terminal alkynylated A-block was successfully prepared.
在任意实施方式中，所述制备BAB型嵌段共聚物的方法包括：In any embodiment, the method for preparing a BAB type block copolymer comprises:
将两端均具有叠氮基团或炔基作为端基的所述A-嵌段与末端具有炔基或叠氮基团作为端基的所述B-嵌段混合，进行点击反应，制备BAB型嵌段共聚物，其中所述A-嵌段和所述B-嵌段的端基不同。The A-block having an azide group or an alkynyl group as an end group at both ends is mixed with the B-block having an alkynyl group or an azide group as an end group at the end, and a click reaction is performed to prepare a BAB type block copolymer, wherein the end groups of the A-block and the B-block are different.
上述制备方法，具有高效稳定，高特异性的优点，提高产品的良品率。The above preparation method has the advantages of high efficiency, stability and high specificity, and improves the yield rate of the product.
在任意实施方式中，链转移剂为含末端炔基或叠氮基团的RAFT链转移剂。In any embodiment, the chain transfer agent is a RAFT chain transfer agent containing a terminal alkynyl or azide group.
在任意实施方式中，所述第一引发剂为偶氮引发剂，选自偶氮二异丁腈，偶氮二异庚腈的一种或两种。In any embodiment, the first initiator is an azo initiator, selected from one or both of azobisisobutyronitrile and azobisisoheptanenitrile.
在任意实施方式中，所述第二引发剂为对称型双官能度引发剂，选自4-(氯甲基)过氧化苯甲酰。In any embodiment, the second initiator is a symmetrical bifunctional initiator selected from 4-(chloromethyl)benzoyl peroxide.
本申请的第三方面提供任意实施方式中的BAB型嵌段共聚物或任意实施方式中的制备方法制备的BAB型嵌段共聚物在二次电池中的应用。The third aspect of the present application provides the use of the BAB type block copolymer in any embodiment or the BAB type block copolymer prepared by the preparation method in any embodiment in a secondary battery.
本申请的第四方面提供一种正极极片，包括正极集流体以及设置在正极集流体至少一个表面的正极膜层，所述正极膜层包括正极活性物质、导电剂和粘结剂，所述粘结剂为任意实施方式中的BAB型嵌段共聚物或任意实施方式中的制备方法制备的BAB型嵌段共聚物。The fourth aspect of the present application provides a positive electrode plate, including a positive electrode current collector and a positive electrode film layer arranged on at least one surface of the positive electrode current collector, the positive electrode film layer includes a positive electrode active material, a conductive agent and a binder, and the binder is a BAB type block copolymer in any embodiment or a BAB type block copolymer prepared by the preparation method in any embodiment.
该正极极片具有优异的柔韧性和粘结力，同时具有较低的膜片电阻。The positive electrode sheet has excellent flexibility and adhesion, as well as low membrane resistance.
在任意实施方式中，所述粘结剂的质量分数为0.1％-3％，所述粘结剂的质量分数可选为1％-3％，基于所述正极活性物质的总质量计。In any embodiment, the mass fraction of the binder is 0.1%-3%, and the mass fraction of the binder can be optionally 1%-3%, based on the total mass of the positive electrode active material.
控制粘结剂的质量分数在合理范围内，能够显著减缓浆料的凝胶现象，提高浆料稳定性，提高极片的柔性，并提高电池的循环容量保 持率。Controlling the mass fraction of the binder within a reasonable range can significantly slow down the gelation of the slurry, improve the stability of the slurry, increase the flexibility of the electrode, and increase the cycle capacity of the battery. Holding rate.
在任意实施方式中，所述正极膜层与所述正极集流体间单位长度的粘结力不小于8N/m，可选地正极膜层与所述正极集流体间单位长度的粘结力不小于10N/m。In any embodiment, the bonding force per unit length between the positive electrode film layer and the positive electrode current collector is not less than 8 N/m, and optionally, the bonding force per unit length between the positive electrode film layer and the positive electrode current collector is not less than 10 N/m.
该极片的正极膜层与正极集流体之间具有高的粘结强度，在使用过程中，正极膜层不容易从正极集流体上脱落，有助于提高电池的循环性能和安全性。The positive electrode film layer of the pole piece has high bonding strength with the positive electrode current collector. During use, the positive electrode film layer is not easy to fall off from the positive electrode current collector, which helps to improve the cycle performance and safety of the battery.
在任意实施方式中，所述正极极片在经过不少于3次的弯折测试后，所述正极极片出现透光现象。In any embodiment, after the positive electrode plate has been subjected to no less than three bending tests, the positive electrode plate becomes light-transmissive.
该极片具有优异的柔韧性，不易在生产过程中出现极片崩裂的现象，有助于提高良品率。The electrode has excellent flexibility and is not prone to cracking during the production process, which helps to improve the yield rate.
在任意实施方式中，所述正极极片的膜片电阻≤0.52Ω，可选地正极极片的膜片电阻≤0.46Ω。In any embodiment, the diaphragm resistance of the positive electrode plate is ≤0.52Ω, and optionally the diaphragm resistance of the positive electrode plate is ≤0.46Ω.
在本申请的第五方面，提供一种二次电池，包括电极组件和电解液，所述电极组件包括隔离膜、负极极片和本申请第四方面的正极极片，可选地，所述二次电池包括锂离子电池、钠离子电池、镁离子电池、钾离子电池中的至少一种。In the fifth aspect of the present application, a secondary battery is provided, comprising an electrode assembly and an electrolyte, wherein the electrode assembly comprises a separator, a negative electrode plate and the positive electrode plate of the fourth aspect of the present application. Optionally, the secondary battery comprises at least one of a lithium ion battery, a sodium ion battery, a magnesium ion battery and a potassium ion battery.
在本申请的第六方面，提供一种用电装置，包括本申请第五方面的二次电池。In a sixth aspect of the present application, an electrical device is provided, comprising the secondary battery of the fifth aspect of the present application.
附图说明BRIEF DESCRIPTION OF THE DRAWINGS
图1是本申请一实施方式的BAB型嵌段共聚物的制备示意图；FIG1 is a schematic diagram of the preparation of a BAB type block copolymer according to an embodiment of the present application;
图2是本申请一实施方式的二次电池的示意图；FIG2 is a schematic diagram of a secondary battery according to an embodiment of the present application;
图3是图2所示的本申请一实施方式的二次电池的分解图；FIG3 is an exploded view of the secondary battery of one embodiment of the present application shown in FIG2 ;
图4是本申请一实施方式的电池模块的示意图；FIG4 is a schematic diagram of a battery module according to an embodiment of the present application;
图5是本申请一实施方式的电池包的示意图；FIG5 is a schematic diagram of a battery pack according to an embodiment of the present application;
图6是图5所示的本申请一实施方式的电池包的分解图；FIG6 is an exploded view of the battery pack according to an embodiment of the present application shown in FIG5 ;
图7是本申请一实施方式的二次电池用作电源的用电装置的示 意图。FIG. 7 is a diagram of an electric device in which a secondary battery is used as a power source in one embodiment of the present application. intention.
附图标记说明：Description of reference numerals:
1电池包；2上箱体；3下箱体；4电池模块；5二次电池；51壳体；52电极组件；53盖板；6BAB型嵌段共聚物；61A-嵌段；611A-嵌段的两端基团；62B-嵌段；621B-嵌段的末端基团。1 battery pack; 2 upper box; 3 lower box; 4 battery module; 5 secondary battery; 51 shell; 52 electrode assembly; 53 cover plate; 6BAB type block copolymer; 61A-block; 611A-two end groups of the block; 62B-block; 621B-end groups of the block.
具体实施方式Detailed ways
以下，适当地参照附图详细说明具体公开了本申请的正极活性材料及其制造方法、正极极片、二次电池、电池模块、电池包和电学装置的实施方式。但是会有省略不必要的详细说明的情况。例如，有省略对已众所周知的事项的详细说明、实际相同结构的重复说明的情况。这是为了避免以下的说明不必要地变得冗长，便于本领域技术人员的理解。此外，附图及以下说明是为了本领域技术人员充分理解本申请而提供的，并不旨在限定权利要求书所记载的主题。Below, the embodiments of the positive electrode active material and its manufacturing method, positive electrode sheet, secondary battery, battery module, battery pack and electrical device of the present application are specifically disclosed with appropriate reference to the drawings. However, there are cases where unnecessary detailed descriptions are omitted. For example, there are cases where detailed descriptions of well-known matters and repeated descriptions of actually the same structure are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the drawings and the following descriptions are provided for those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.
本申请所公开的“范围”以下限和上限的形式来限定，给定范围是通过选定一个下限和一个上限进行限定的，选定的下限和上限限定了特别范围的边界。这种方式进行限定的范围可以是包括端值或不包括端值的，并且可以进行任意地组合，即任何下限可以与任何上限组合形成一个范围。例如，如果针对特定参数列出了60-120和80-110的范围，理解为60-110和80-120的范围也是预料到的。此外，如果列出的最小范围值1和2，和如果列出了最大范围值3，4和5，则下面的范围可全部预料到：1-3、1-4、1-5、2-3、2-4和2-5。在本申请中，除非有其他说明，数值范围“a-b”表示a到b之间的任意实数组合的缩略表示，其中a和b都是实数。例如数值范围“0-5”表示本文中已经全部列出了“0-5”之间的全部实数，“0-5”只是这些数值组合的缩略表示。另外，当表述某个参数为≥2的整数，则相当于公开了该参数为例如整数2、3、4、5、6、7、8、9、10、11、12等。The "range" disclosed in the present application is defined in the form of a lower limit and an upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of a particular range. The range defined in this way can be inclusive or exclusive of end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range. For example, if a range of 60-120 and 80-110 is listed for a specific parameter, it is understood that the range of 60-110 and 80-120 is also expected. In addition, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4 and 5 are listed, the following ranges can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present application, unless otherwise specified, the numerical range "a-b" represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers. For example, the numerical range "0-5" represents that all real numbers between "0-5" have been fully listed herein, and "0-5" is just the abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.
如果没有特别的说明，本申请的所有实施方式以及可选实施方式 可以相互组合形成新的技术方案。Unless otherwise specified, all embodiments and optional embodiments of the present application are They can be combined with each other to form new technical solutions.
如果没有特别的说明，本申请的所有技术特征以及可选技术特征可以相互组合形成新的技术方案。Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.
如果没有特别的说明，本申请的所有步骤可以顺序进行，也可以随机进行，优选是顺序进行的。例如，所述方法包括步骤(a)和(b)，表示所述方法可包括顺序进行的步骤(a)和(b)，也可以包括顺序进行的步骤(b)和(a)。例如，所述提到所述方法还可包括步骤(c)，表示步骤(c)可以任意顺序加入到所述方法，例如，所述方法可以包括步骤(a)、(b)和(c)，也可包括步骤(a)、(c)和(b)，也可以包括步骤(c)、(a)和(b)等。If there is no special explanation, all steps of the present application can be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.
如果没有特别的说明，本申请所提到的“包括”和“包含”表示开放式，也可以是封闭式。例如，所述“包括”和“包含”可以表示还可以包括或包含没有列出的其他组分，也可以仅包括或包含列出的组分。If there is no special explanation, the "include" and "comprising" mentioned in this application represent open-ended or closed-ended expressions. For example, the "include" and "comprising" may represent that other components not listed may also be included or only the listed components may be included or only the listed components may be included.
如果没有特别的说明，在本申请中，术语“或”是包括性的。举例来说，短语“A或B”表示“A，B，或A和B两者”。更具体地，以下任一条件均满足条件“A或B”：A为真(或存在)并且B为假(或不存在)；A为假(或不存在)而B为真(或存在)；或A和B都为真(或存在)。If not specifically stated, in this application, the term "or" is inclusive. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, any of the following conditions satisfies the condition "A or B": A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).
传统的粘结剂生产成本高、产能不足，对环境危害大，且在制备过程中容易出现凝胶，导致浆料稳定性差、加工成本高，以其制备的极片柔性差、粘结力低、电阻高、良品率低，电池的直流阻抗增长率高、循环容量保持率低、性能不稳定，难以满足市场对于电池成本和性能的要求。因此，现有的粘结剂仍有待改进。Traditional binders have high production costs, insufficient production capacity, and great environmental hazards. They are prone to gelation during the preparation process, resulting in poor slurry stability and high processing costs. The pole pieces prepared with them have poor flexibility, low bonding force, high resistance, and low yield. The battery has a high DC impedance growth rate, low cycle capacity retention rate, and unstable performance, making it difficult to meet the market's requirements for battery cost and performance. Therefore, existing binders still need to be improved.
[粘结剂][Binder]
基于此，本申请提出了一种BAB型嵌段共聚物，包含A-嵌段和B-嵌段，所述A-嵌段含有衍生自式I所示单体的结构单元，所述B-嵌段含有衍生自式II所示单体的结构单元；Based on this, the present application proposes a BAB type block copolymer, comprising an A-block and a B-block, wherein the A-block contains a structural unit derived from a monomer represented by formula I, and the B-block contains a structural unit derived from a monomer represented by formula II;
或者所述A-嵌段含有衍生自式II所示单体的结构单元，所述B-嵌段含有衍生自I所示单体的结构单元，
Alternatively, the A-block contains structural units derived from the monomers of formula II, and the B-block contains structural units derived from the monomers of formula I,
其中R1、R2、R3各自独立地选自氢、氟、至少含有一个氟原子的C1-3烷基中的一种或多种，R4、R5、R6各自独立地选自氢、取代或未取代的C1-5烷基。R 1 , R 2 , and R 3 are each independently selected from one or more of hydrogen, fluorine, and C 1-3 alkyl containing at least one fluorine atom; and R 4 , R 5 , and R 6 are each independently selected from hydrogen, and substituted or unsubstituted C 1-5 alkyl.
在一些实施方式中，B-嵌段还含有衍生自式III所示单体的结构单元，
In some embodiments, the B-block further comprises a structural unit derived from a monomer of formula III,
其中R7、R8、R9各自独立地选自氢、取代或未取代的C1-5烷基，R10选自酯基、氰基、酰胺基中的一种。R 7 , R 8 and R 9 are each independently selected from hydrogen, substituted or unsubstituted C 1-5 alkyl, and R 10 is selected from one of ester group, cyano group and amide group.
在本文中，术语“粘结剂”是指在分散介质中形成胶体溶液或胶体分散液的化学化合物、聚合物或混合物。As used herein, the term "binder" refers to a chemical compound, polymer or mixture that forms a colloidal solution or colloidal dispersion in a dispersion medium.
在本文中，术语“嵌段共聚物”是将两种或两种以上性质不同的聚合物链段连在一起制备而成的一种特殊聚合物。具有特定结构的嵌段聚合物会表现出与简单线形聚合物，以及许多无规共聚物甚至均聚物的混合物不同的性质。常见的有AB型和BAB型，其中A、B都是长链段；也有(AB)n型多段共聚物，其中A、B链段相对较短。In this article, the term "block copolymer" refers to a special type of polymer made by linking two or more polymer segments with different properties. Block polymers with specific structures will exhibit different properties from simple linear polymers, many random copolymers, and even mixtures of homopolymers. Common types include AB and BAB types, in which A and B are both long chain segments; there are also (AB)n type multi-segment copolymers, in which A and B segments are relatively short.
在本文中，术语“BAB型嵌段共聚物”是指中间为A-嵌段，两侧为B-嵌段的三嵌段共聚物。其中，A-嵌段和B-嵌段分别是由不同的单体聚合形成的具有预定重均分子量的聚合物链段。在一些实施方式中，A-嵌段是由含氟单体聚合形成的长序列链段，B-嵌段是由一种或 多种不含氟单体聚合形成的长序列链段。A-嵌段和B-嵌段以有序的方式经共价键结合形成BAB型嵌段共聚物。以本申请的实施例1为例，其中A-嵌段为聚偏二氟乙烯，重均分子量为45万g/mol，由偏氟乙烯单体聚合形成；B-嵌段为聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)，重均分子量为40万g/mol，由丙烯酸、甲基丙烯酸乙酯以及丙烯酰胺单体聚合形成；最终合成得到的BAB型嵌段共聚物为聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)-聚偏二氟乙烯-聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)三嵌段共聚物，重均分子量为120万g/mol。In this article, the term "BAB type block copolymer" refers to a triblock copolymer with an A-block in the middle and B-blocks on both sides. The A-block and the B-block are polymer segments with a predetermined weight average molecular weight formed by polymerization of different monomers. In some embodiments, the A-block is a long sequence segment formed by polymerization of a fluorinated monomer, and the B-block is a polymer segment formed by polymerization of one or more monomers. A long sequence segment formed by polymerization of a variety of fluorine-free monomers. A-blocks and B-blocks are covalently bonded in an orderly manner to form a BAB type block copolymer. Taking Example 1 of the present application as an example, wherein A-block is polyvinylidene fluoride, and the weight average molecular weight is 450,000 g/mol, which is formed by polymerization of vinylidene fluoride monomers; B-block is poly (acrylic acid-acrylamide-ethyl methacrylate), and the weight average molecular weight is 400,000 g/mol, which is formed by polymerization of acrylic acid, ethyl methacrylate and acrylamide monomers; The BAB type block copolymer finally synthesized is poly (acrylic acid-acrylamide-ethyl methacrylate)-polyvinylidene fluoride-poly (acrylic acid-acrylamide-ethyl methacrylate) triblock copolymer, and the weight average molecular weight is 1.2 million g/mol.
在一些实施方式中，BAB型嵌段共聚物中A-嵌段含有衍生自式I所示单体的结构单元，B-嵌段含有衍生自式II所示单体的结构单元。In some embodiments, the A-block of the BAB-type block copolymer contains structural units derived from the monomer of Formula I, and the B-block contains structural units derived from the monomer of Formula II.
在一些实施方式中，BAB型嵌段共聚物中A-嵌段含有衍生自式I所示单体的结构单元，B-嵌段含有衍生自式II和式III所示单体的结构单元。In some embodiments, the A-block in the BAB-type block copolymer contains structural units derived from the monomers represented by Formula I, and the B-block contains structural units derived from the monomers represented by Formula II and Formula III.
在一些实施方式中，BAB型嵌段共聚物中A-嵌段含有衍生自式II所示单体的结构单元，B-嵌段含有衍生自式I所示单体的结构单元。In some embodiments, the A-block in the BAB-type block copolymer contains structural units derived from the monomer represented by Formula II, and the B-block contains structural units derived from the monomer represented by Formula I.
在一些实施方式中，BAB型嵌段共聚物中A-嵌段含有衍生自式II和式III所示单体的结构单元，B-嵌段含有衍生自式I所示单体的结构单元。In some embodiments, the A-block in the BAB type block copolymer contains structural units derived from monomers represented by Formula II and Formula III, and the B-block contains structural units derived from monomers represented by Formula I.
在一些实施方式中，A-嵌段是由一种或多种不含氟单体聚合形成的长序列链段，B-嵌段是由一种或多种含氟单体聚合形成的长序列链段。A-嵌段和B-嵌段以有序的方式经共价键结合形成BAB型嵌段共聚物。以实施例25中制备的BAB型嵌段聚合物为例，其中A-嵌段为聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)，由丙烯酸、丙烯酰胺、甲基丙烯酸乙酯单体聚合形成，重均分子量为66万g/mol；B-嵌段为聚偏二氟乙烯，由偏二氟乙烯单体聚合形成，重均分子量为27万g/mol；B-嵌段和A-嵌段的两侧的端基键合得到聚偏二氟乙烯-聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)-聚偏二氟乙烯嵌段共聚物(BAB型嵌段共聚物)，该嵌段共聚物的重均分子量为120万g/mol。 In some embodiments, the A-block is a long sequence segment formed by the polymerization of one or more fluorine-free monomers, and the B-block is a long sequence segment formed by the polymerization of one or more fluorine-containing monomers. The A-block and the B-block are covalently bonded in an orderly manner to form a BAB type block copolymer. Taking the BAB type block polymer prepared in Example 25 as an example, the A-block is poly (acrylic acid-acrylamide-ethyl methacrylate), which is polymerized by acrylic acid, acrylamide, and ethyl methacrylate monomers, and the weight average molecular weight is 660,000 g/mol; the B-block is polyvinylidene fluoride, which is polymerized by vinylidene fluoride monomers, and the weight average molecular weight is 270,000 g/mol; the end groups on both sides of the B-block and the A-block are bonded to obtain polyvinylidene fluoride-poly (acrylic acid-acrylamide-ethyl methacrylate)-polyvinylidene fluoride block copolymer (BAB type block copolymer), and the weight average molecular weight of the block copolymer is 1.2 million g/mol.
在本文中，术语“聚合物”一方面包括通过聚合反应制备的化学上均一的、但在聚合度、摩尔质量和链长方面不同的大分子的集合体。该术语另一方面也包括由聚合反应形成的这样的大分子集合体的衍生物，即可以通过上述大分子中的官能团的反应，例如加成或取代获得的并且可以是化学上均一的或化学上不均一的化合物。In this context, the term "polymer" includes, on the one hand, a collection of macromolecules that are chemically uniform but differ in degree of polymerization, molar mass and chain length, prepared by polymerization. The term also includes, on the other hand, derivatives of such a collection of macromolecules formed by polymerization, i.e. compounds that can be obtained by reaction, for example addition or substitution, of functional groups in the above-mentioned macromolecules and can be chemically uniform or chemically heterogeneous.
在本文中，术语“酯基”指的是-COOR11基团，R11选自被取代基取代或未取代的烷基。As used herein, the term "ester group" refers to a -COOR 11 group, wherein R 11 is selected from an alkyl group which may be substituted or unsubstituted.
在本文中，术语“酰胺基”指的是R12、R13各自独立地选自氢、取代或未取代基的烷基。As used herein, the term "amide group" refers to R 12 and R 13 are each independently selected from hydrogen, and substituted or unsubstituted alkyl.
在本文中，术语“氰基”是指-CN基团。As used herein, the term "cyano" refers to a -CN group.
在一些实施方式中，粘结剂的分散介质是水性溶剂，如水。即粘结剂溶解于水性溶剂中。In some embodiments, the dispersion medium of the binder is an aqueous solvent, such as water, that is, the binder is dissolved in the aqueous solvent.
在一些实施方式中，粘结剂的分散介质是油性溶剂，油性溶剂的示例包括但不限于二甲基乙酰胺、N,N-二甲基甲酰胺、N-甲基吡咯烷酮、丙酮、碳酸二甲酯、乙基纤维素、聚碳酸酯。即，粘结剂溶解于油性溶剂中。In some embodiments, the dispersion medium of the binder is an oily solvent, examples of which include but are not limited to dimethylacetamide, N,N-dimethylformamide, N-methylpyrrolidone, acetone, dimethyl carbonate, ethyl cellulose, and polycarbonate. That is, the binder is dissolved in the oily solvent.
在一些实施方式中，粘结剂用于将电极材料及/或导电剂固定在合适位置并将它们粘附在导电金属部件以形成电极。In some embodiments, a binder is used to hold the electrode material and/or the conductive agent in place and adhere them to the conductive metal part to form an electrode.
在一些实施方式中，粘结剂作为正极粘结剂，用于粘结正极活性材料及/或导电剂以形成电极。In some embodiments, the binder is used as a positive electrode binder to bind the positive electrode active material and/or the conductive agent to form an electrode.
在一些实施方式中，粘结剂作为负极粘结剂，用于粘结负极活性材料及/或导电剂以形成电极。In some embodiments, the binder is used as a negative electrode binder to bind the negative electrode active material and/or the conductive agent to form an electrode.
在本文中，术语“C1-3烷基”是指仅由碳和氢原子组成的直链或支链烃链基团，基团中不存在不饱和，具有从一至三个碳原子，并且通过单键附接到分子的其余部分。C1-3烷基的示例包括但不限于：甲基、乙基、正丙基、正丁基、1-甲基乙基(异丙基)。As used herein, the term "C 1-3 alkyl" refers to a straight or branched hydrocarbon chain radical consisting solely of carbon and hydrogen atoms, with no unsaturation in the radical, having from one to three carbon atoms, and attached to the remainder of the molecule by a single bond. Examples of C 1-3 alkyl include, but are not limited to: methyl, ethyl, n-propyl, n-butyl, 1-methylethyl (isopropyl).
在本文中，术语“C1-5烷基”是指仅由碳和氢原子组成的直链或支 链烃链基团，基团中不存在不饱和，具有从一至五个碳原子，并且通过单键附接到分子的其余部分。C1-5烷基的示例包括但不限于：甲基、乙基、正丙基、1-甲基乙基(异丙基)、正丁基、叔丁基、异戊基。In this context, the term "C 1-5 alkyl" refers to a straight or branched chain consisting only of carbon and hydrogen atoms. A hydrocarbon chain radical, with no unsaturation in the radical, having from one to five carbon atoms, and attached to the rest of the molecule by a single bond. Examples of C 1-5 alkyl groups include, but are not limited to: methyl, ethyl, n-propyl, 1-methylethyl (isopropyl), n-butyl, tert-butyl, isopentyl.
在本文中，术语“取代的”是指该化合物或化学部分的至少一个氢原子被另一种化学部分被取代基取代，其中的取代基各自独立地选自：羟基、巯基、氨基、氰基、硝基、醛基、卤素原子、烯基、炔基、芳基、杂芳基、C1-6烷基、C1-6烷氧基。As used herein, the term "substituted" means that at least one hydrogen atom of the compound or chemical moiety is replaced by another chemical moiety with a substituent, wherein the substituent is independently selected from: hydroxyl, thiol, amino, cyano, nitro, aldehyde, halogen atom, alkenyl, alkynyl, aryl, heteroaryl, C 1-6 alkyl, C 1-6 alkoxy.
在一些实施方式中，式I中的R1为氟，R2、R3各自独立地选自氢、氟、氯或三氟甲基。In some embodiments, R 1 in Formula I is fluorine, and R 2 and R 3 are each independently selected from hydrogen, fluorine, chlorine or trifluoromethyl.
在本文中，术语“三氟甲基”是指-CF3基团。As used herein, the term "trifluoromethyl" refers to a -CF3 group.
在一些实施方式中，A-嵌段中衍生自式I所示单体的结构单元的摩尔含量为30％-70％，基于嵌段共聚物中所有结构单元的总摩尔数计。在一些实施方式中，A-嵌段中衍生自式I所示单体的结构单元的摩尔含量可选为30％-35％、35％-40％、40％-45％、45％-50％、50％-55％、55％-60％、60％-65％、65％-70％、30％-40％、40％-50％、50％-60％、60％-70％、35％-45％、45％-55％、55％-65％、30％-45％、45％-60％、35％-50％、50％-65％、40％-55％、55％-70％、30％-50％、50％-70％、35％-55％、40％-60％、45％-65％、30％-55％、35％-60％、40％-65％、45％-70％、30％-60％、35％-65％、40％-70％、30％-65％、35％-70％中的任意一种，基于嵌段共聚物中所有结构单元的总摩尔数计。In some embodiments, the molar content of the structural units derived from the monomers shown in Formula I in the A-block is 30%-70%, based on the total moles of all structural units in the block copolymer. In some embodiments, the molar content of the structural units derived from the monomers shown in Formula I in the A-block can be selected from 30%-35%, 35%-40%, 40%-45%, 45%-50%, 50%-55%, 55%-60%, 60%-65%, 65%-70%, 30%-40%, 40%-50%, 50%-60%, 60%-70%, 35%-45%, 45%-55%, 55%-65%, 30%-45%, 45%-60% %, 35%-50%, 50%-65%, 40%-55%, 55%-70%, 30%-50%, 50%-70%, 35%-55%, 40%-60%, 45%-65%, 30%-55%, 35%-60%, 40%-65%, 45%-70%, 30%-60%, 35%-65%, 40%-70%, 30%-65%, 35%-70%, based on the total moles of all structural units in the block copolymer.
若A-嵌段中衍生自式I所示单体的结构单元的摩尔含量过低，极片的粘结力下降；若A-嵌段中衍生自式I所示单体的结构单元的摩尔含量过高，加快浆料的凝胶现象，降低浆料稳定性，膜片电阻变大。If the molar content of the structural unit derived from the monomer shown in Formula I in the A-block is too low, the bonding force of the electrode will decrease; if the molar content of the structural unit derived from the monomer shown in Formula I in the A-block is too high, the gelation of the slurry will be accelerated, the slurry stability will be reduced, and the membrane resistance will increase.
控制A-嵌段中衍生自式I所示单体的结构单元的摩尔含量在合适范围内，能够有效减缓浆料的凝胶现象，提高浆料的稳定性，提高极片的柔性，降低膜片电阻，并提高电池的循环容量保持率。Controlling the molar content of the structural unit derived from the monomer represented by Formula I in the A-block within a suitable range can effectively slow down the gelation of the slurry, improve the stability of the slurry, increase the flexibility of the pole piece, reduce the membrane resistance, and improve the cycle capacity retention rate of the battery.
在一些实施方式中，A-嵌段中衍生自式I所示单体的结构单元的 摩尔含量为40％-60％，基于嵌段共聚物中所有结构单元的总摩尔数计。在一些实施方式中，A-嵌段中衍生自式I所示单体的结构单元的摩尔含量可选为40％-45％、45％-50％、50％-55％、55％-60％、40％-50％、50％-60％、45％-55％、45％-60％、40％-55％、40％-60％、45％-65％中的任意一种，基于嵌段共聚物中所有结构单元的总摩尔数计。In some embodiments, the structural units derived from the monomers of Formula I in the A-block are The molar content is 40%-60%, based on the total moles of all structural units in the block copolymer. In some embodiments, the molar content of the structural unit derived from the monomer shown in Formula I in the A-block can be selected from any one of 40%-45%, 45%-50%, 50%-55%, 55%-60%, 40%-50%, 50%-60%, 45%-55%, 45%-60%, 40%-55%, 40%-60%, 45%-65%, based on the total moles of all structural units in the block copolymer.
控制A-嵌段中衍生自式I所示单体的结构单元的摩尔含量在合适范围内，可以兼顾电池的直流阻抗增长率和循环容量保持率，综合改善电池的电化学性能。By controlling the molar content of the structural unit derived from the monomer represented by Formula I in the A-block within a suitable range, the DC impedance growth rate and the cycle capacity retention rate of the battery can be taken into account, thereby comprehensively improving the electrochemical performance of the battery.
在一些实施方式中，B-嵌段中衍生自式I所示单体的结构单元的摩尔含量为30％-70％，基于嵌段共聚物中所有结构单元的总摩尔数计。在一些实施方式中，B-嵌段中衍生自式I所示单体的结构单元的摩尔含量可选为30％-35％、35％-40％、40％-45％、45％-50％、50％-55％、55％-60％、60％-65％、65％-70％、30％-40％、40％-50％、50％-60％、60％-70％、35％-45％、45％-55％、55％-65％、30％-45％、45％-60％、35％-50％、50％-65％、40％-55％、55％-70％、30％-50％、50％-70％、35％-55％、40％-60％、45％-65％、30％-55％、35％-60％、40％-65％、45％-70％、30％-60％、35％-65％、40％-70％、30％-65％、35％-70％中的任意一种，基于嵌段共聚物中所有结构单元的总摩尔数计。In some embodiments, the molar content of the structural unit derived from the monomer shown in Formula I in the B-block is 30%-70%, based on the total moles of all structural units in the block copolymer. In some embodiments, the molar content of the structural unit derived from the monomer shown in Formula I in the B-block can be selected from 30%-35%, 35%-40%, 40%-45%, 45%-50%, 50%-55%, 55%-60%, 60%-65%, 65%-70%, 30%-40%, 40%-50%, 50%-60%, 60%-70%, 35%-45%, 45%-55%, 55%-65%, 30%-45%, 45%-60% %, 35%-50%, 50%-65%, 40%-55%, 55%-70%, 30%-50%, 50%-70%, 35%-55%, 40%-60%, 45%-65%, 30%-55%, 35%-60%, 40%-65%, 45%-70%, 30%-60%, 35%-65%, 40%-70%, 30%-65%, 35%-70%, based on the total moles of all structural units in the block copolymer.
控制B-嵌段中衍生自式I所示单体的结构单元的摩尔含量在合适范围内，能够减缓浆料的凝胶现象，提高浆料的稳定性，降低极片的膜片电阻，降低电池的直流阻抗增长率。Controlling the molar content of the structural unit derived from the monomer represented by Formula I in the B-block within a suitable range can slow down the gelation of the slurry, improve the stability of the slurry, reduce the film resistance of the pole piece, and reduce the DC impedance growth rate of the battery.
在一些实施方式中，B-嵌段中衍生自式I所示单体的结构单元的摩尔含量为40％-60％，基于嵌段共聚物中所有结构单元的总摩尔数计。在一些实施方式中，B-嵌段中衍生自式I所示单体的结构单元的摩尔含量可选为40％-45％、45％-50％、50％-55％、55％-60％、40％-50％、50％-60％、45％-55％、45％-60％、35％-50％、50％-65％、40％-55％、40％-60％中的任意一种，基于嵌段共聚物中所有结构单元的总摩尔数计。 In some embodiments, the molar content of the structural unit derived from the monomer shown in Formula I in the B-block is 40%-60%, based on the total moles of all structural units in the block copolymer. In some embodiments, the molar content of the structural unit derived from the monomer shown in Formula I in the B-block can be selected from any one of 40%-45%, 45%-50%, 50%-55%, 55%-60%, 40%-50%, 50%-60%, 45%-55%, 45%-60%, 35%-50%, 50%-65%, 40%-55%, 40%-60%, based on the total moles of all structural units in the block copolymer.
控制B-嵌段中衍生自式I所示单体的结构单元的摩尔含量在合适范围内，能够兼顾极片的膜片电阻和电池的循环容量保持率，综合改善电池的性能。By controlling the molar content of the structural unit derived from the monomer represented by Formula I in the B-block within a suitable range, it is possible to take into account both the film resistance of the electrode and the cycle capacity retention rate of the battery, thereby comprehensively improving the performance of the battery.
在一些实施方式中，嵌段共聚物的重均分子量为40万-200万。在一些实施方式中，嵌段共聚物的重均分子量可选为40万-60万、60万-80万、80万-100万、100万-120万、120万-140万、140万-160万、160万-180万、180万-200万、60万-90万、90万-120万、120万-150万、150万-180万、180万-200万、120万-200万中的任意一种。In some embodiments, the weight average molecular weight of the block copolymer is 400,000-2,000,000. In some embodiments, the weight average molecular weight of the block copolymer can be selected from 400,000-600,000, 600,000-800,000, 800,000-1,000,000, 1,000,000-1,200,000, 1,200,000-1,400,000, 1,400,000-1,600,000, 1,600,000-1,800,000, 1,800,000-2,000,000, 600,000-900,000, 900,000-1,200,000, 1,200,000-1,500,000, 1,500,000-1,800,000, 1,800,000-2,000,000, and any one of 1,200,000-2,000,000.
在本文中，术语“重均分子量”是指聚合物中用不同分子量的分子所占的重量分数与其对应的分子量乘积的总和。As used herein, the term "weight average molecular weight" refers to the sum of the products of the weight fractions of molecules with different molecular weights in a polymer and their corresponding molecular weights.
若嵌段共聚物的重均分子量过大，粘结剂溶解困难，易与导电剂团聚，膜片内阻增大，另外浆料的粘度较大，降低粘结的分散性，影响极片的柔韧性；若嵌段共聚物的重均分子量过小，较难形成三维网状粘结结构，无法起到有效的粘结作用，另外膜片内阻变大。If the weight-average molecular weight of the block copolymer is too large, the binder will be difficult to dissolve and will easily agglomerate with the conductive agent, increasing the internal resistance of the diaphragm. In addition, the viscosity of the slurry will be relatively large, reducing the dispersion of the bonding and affecting the flexibility of the electrode. If the weight-average molecular weight of the block copolymer is too small, it will be difficult to form a three-dimensional network bonding structure, and it will not be able to play an effective bonding role. In addition, the internal resistance of the diaphragm will increase.
控制嵌段共聚物的重均分子量在合适范围内，能够有效减缓浆料的凝胶现象，提高浆料的稳定性，提高极片的柔性，提高粘结力，降低膜片电阻，降低电池的直流阻抗增长率，并提高电池的循环容量保持率。Controlling the weight-average molecular weight of the block copolymer within an appropriate range can effectively slow down the gelation of the slurry, improve the stability of the slurry, increase the flexibility of the pole piece, increase the bonding force, reduce the membrane resistance, reduce the DC impedance growth rate of the battery, and improve the cycle capacity retention rate of the battery.
在一些实施方式中，所述嵌段共聚物中，含有衍生自式I所示单体的结构单元的A-嵌段的重均分子量为20万-105万。在一些实施方式中，含有衍生自式I所示单体的结构单元的A-嵌段的重均分子量可选为20万-30万、30万-40万、40万-50万、50万-60万、60万-70万、70万-80万、80万-90万、90万-105万、40万-60万、40万-80万、40万-105万中的任意一种。In some embodiments, in the block copolymer, the weight average molecular weight of the A-block containing the structural unit derived from the monomer shown in Formula I is 200,000-1,050,000. In some embodiments, the weight average molecular weight of the A-block containing the structural unit derived from the monomer shown in Formula I can be selected from any one of 200,000-300,000, 300,000-400,000, 400,000-500,000, 500,000-600,000, 600,000-700,000, 700,000-800,000, 800,000-900,000, 900,000-1,050,000, 400,000-600,000, 400,000-800,000, and 400,000-1,050,000.
若嵌段共聚物中含有衍生自式I所示单体的结构单元的A-嵌段的重均分子量过大，衍生自式I所示单体的结构单元强极性基团过多，影响浆料的稳定性；若嵌段共聚物中含有衍生自式I所示单体的结构 单元的A-嵌段的重均分子量过小，极片的粘结力下降。If the weight average molecular weight of the A-block containing the structural unit derived from the monomer shown in Formula I in the block copolymer is too large, the structural unit derived from the monomer shown in Formula I has too many strong polar groups, which affects the stability of the slurry; if the block copolymer contains the structural unit derived from the monomer shown in Formula I If the weight average molecular weight of the A-block of the unit is too small, the bonding strength of the electrode sheet will decrease.
控制嵌段共聚物中含有衍生自式I所示单体的结构单元的A-嵌段的重均分子量在合适范围内，能够有效减缓浆料的凝胶现象，提高浆料的稳定性，提高极片的柔性，降低膜片电阻，并提高电池的循环容量保持率。Controlling the weight average molecular weight of the A-block containing the structural unit derived from the monomer represented by Formula I in the block copolymer within a suitable range can effectively slow down the gelation of the slurry, improve the stability of the slurry, improve the flexibility of the pole piece, reduce the membrane resistance, and improve the cycle capacity retention rate of the battery.
在一些实施方式中，所述嵌段共聚物中，含有衍生自式II所示单体的结构单元或者含有衍生自式II所示单体的结构单元和衍生自式III所示单体的结构单元的A-嵌段的重均分子量为20万-105万。在一些实施方式中，含有衍生自式II所示单体的结构单元或者含有衍生自式II所示单体的结构单元和衍生自式III所示单体的结构单元的A-嵌段的重均分子量可选为20万-30万、30万-40万、40万-50万、50万-60万、60万-70万、70万-80万、80万-90万、90万-105万、40万-60万、40万-80万、40万-105万中的任意一种。In some embodiments, in the block copolymer, the weight average molecular weight of the A-block containing the structural unit derived from the monomer shown in formula II or the structural unit derived from the monomer shown in formula II and the structural unit derived from the monomer shown in formula III is 200,000-1,050,000. In some embodiments, the weight average molecular weight of the A-block containing the structural unit derived from the monomer shown in formula II or the structural unit derived from the monomer shown in formula II and the structural unit derived from the monomer shown in formula III can be selected from any one of 200,000-300,000, 300,000-400,000, 400,000-500,000, 500,000-600,000, 600,000-700,000, 700,000-800,000, 800,000-900,000, 900,000-1,050,000, 400,000-600,000, 400,000-800,000, and 400,000-1,050,000.
控制嵌段共聚物中含有衍生自式I所示单体的结构单元的A-嵌段的重均分子量在合适范围内，能够提高极片的粘结力，降低电池的直流阻抗增长率。By controlling the weight average molecular weight of the A-block containing the structural unit derived from the monomer represented by Formula I in the block copolymer within a suitable range, the bonding force of the pole piece can be improved and the DC impedance growth rate of the battery can be reduced.
在一些实施方式中，所述嵌段共聚物中，每个含有衍生自式II所示单体的结构单元或者含有衍生自式II所示单体的结构单元和衍生自式III所示单体的结构单元的B-嵌段的重均分子量为10万-50万。在一些实施方式中，每个含有衍生自式II所示单体的结构单元或者含有衍生自式II所示单体的结构单元和衍生自式III所示单体的结构单元的B-嵌段的重均分子量可选为10万-20万、20万-30万、30万-40万、40万-50万、20万-40万、20万-50万中的任意一种。In some embodiments, in the block copolymer, the weight average molecular weight of each B-block containing a structural unit derived from a monomer shown in formula II or containing a structural unit derived from a monomer shown in formula II and a structural unit derived from a monomer shown in formula III is 100,000-500,000. In some embodiments, the weight average molecular weight of each B-block containing a structural unit derived from a monomer shown in formula II or containing a structural unit derived from a monomer shown in formula II and a structural unit derived from a monomer shown in formula III can be selected from any one of 100,000-200,000, 200,000-300,000, 300,000-400,000, 400,000-500,000, 200,000-400,000, and 200,000-500,000.
控制嵌段共聚物中每个含有衍生自式II所示单体的结构单元或者含有衍生自式II所示单体的结构单元和衍生自式III所示单体的结构单元的B-嵌段的重均分子量在合适范围内，能够提高粘结力，并提高电池的循环容量保持率。Controlling the weight average molecular weight of each B-block in the block copolymer containing a structural unit derived from the monomer shown in formula II or containing a structural unit derived from the monomer shown in formula II and a structural unit derived from the monomer shown in formula III within a suitable range can improve the bonding force and improve the cycle capacity retention rate of the battery.
在一些实施方式中，所述嵌段共聚物中，每个含有衍生自式I所 示单体的结构单元的B-嵌段的重均分子量为10万-50万。在一些实施方式中，每个含有衍生自式I所示单体的结构单元的B-嵌段的重均分子量可选为10万-20万、20万-30万、30万-40万、40万-50万、20万-40万、20万-50万中的任意一种。In some embodiments, each of the block copolymers contains a The weight average molecular weight of the B-block containing the structural unit derived from the monomer shown in Formula I is 100,000-500,000. In some embodiments, the weight average molecular weight of each B-block containing the structural unit derived from the monomer shown in Formula I can be selected from any one of 100,000-200,000, 200,000-300,000, 300,000-400,000, 400,000-500,000, 200,000-400,000, and 200,000-500,000.
控制嵌段共聚物中每个含有衍生自式I所示单体的结构单元的B-嵌段的重均分子量在合适范围内，能够有效减缓浆料的凝胶现象，提高浆料的稳定性，降低膜片电阻，降低电池的直流阻抗增长率。Controlling the weight average molecular weight of each B-block containing a structural unit derived from the monomer represented by Formula I in the block copolymer within a suitable range can effectively slow down the gelation of the slurry, improve the stability of the slurry, reduce the membrane resistance, and reduce the DC impedance growth rate of the battery.
在一些实施方式中，式I所示单体选自偏氟乙烯、四氟乙烯、氟乙烯、六氟丙烯中的一种或多种。In some embodiments, the monomer represented by formula I is selected from one or more of vinylidene fluoride, tetrafluoroethylene, vinyl fluoride, and hexafluoropropylene.
在一些实施方式中，式II所示单体选自丙烯酸、甲基丙烯酸、乙基丙烯酸中的一种或多种。In some embodiments, the monomer represented by formula II is selected from one or more of acrylic acid, methacrylic acid, and ethacrylic acid.
在一些实施方式中，式III所示单体选自丙烯酰胺、丙烯酸酯、丙烯腈中的一种或多种。在一些实施方式中，式III所示单体选自丙烯酰胺、丙烯酸甲酯、丙烯酸乙酯、甲基丙烯酸甲酯、甲基丙烯酸乙酯、乙基丙烯酸甲酯、乙基丙烯酸乙酯、丙烯腈中的一种或多种。在一些实施方式中，式III所示单体选自丙烯酰胺、甲基丙烯酸乙酯、丙烯腈中的一种或多种。In some embodiments, the monomer of formula III is selected from one or more of acrylamide, acrylate, and acrylonitrile. In some embodiments, the monomer of formula III is selected from one or more of acrylamide, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, methyl ethyl acrylate, ethyl ethyl acrylate, and acrylonitrile. In some embodiments, the monomer of formula III is selected from one or more of acrylamide, ethyl methacrylate, and acrylonitrile.
在一些实施方式中，BAB-嵌段共聚物为聚丙烯酸-聚偏二氟乙烯-聚丙烯酸三嵌段共聚物、聚丙烯酸-聚氟乙烯-聚丙烯酸三嵌段共聚物、聚丙烯酸-聚四氟乙烯-聚丙烯酸三嵌段共聚物、聚(丙烯酸-丙烯酸酯)-聚偏二氟乙烯-聚(丙烯酸-丙烯酸酯)三嵌段共聚物、聚(丙烯酸-丙烯酸酯)-聚氟乙烯-聚(丙烯酸-丙烯酸酯)三嵌段共聚物、聚(丙烯酸-丙烯酸酯)-聚四氟乙烯-聚(丙烯酸-丙烯酸酯)三嵌段共聚物、聚(丙烯酸-丙烯腈-丙烯酸酯)-聚偏二氟乙烯-聚(丙烯酸-丙烯腈-丙烯酸酯)三嵌段共聚物、聚(丙烯酸-丙烯腈-丙烯酸酯)-聚氟乙烯-聚(丙烯酸-丙烯腈-丙烯酸酯)三嵌段共聚物、聚(丙烯酸-丙烯腈-丙烯酸酯)-聚四氟乙烯-聚(丙烯酸-丙烯腈-丙烯酸酯)三嵌段共聚物、聚(丙烯酸-丙烯酰胺-丙烯酸酯)-聚偏二氟乙烯-聚(丙烯酸-丙烯酰胺-丙烯酸酯)三嵌段共聚物、聚(丙烯 酸-丙烯酰胺-丙烯酸酯)-聚氟乙烯-聚(丙烯酸-丙烯酰胺-丙烯酸酯)三嵌段共聚物、聚(丙烯酸-丙烯酰胺-丙烯酸酯)-聚四氟乙烯-聚(丙烯酸-丙烯酰胺-丙烯酸酯)三嵌段共聚物、聚(丙烯酸-丙烯腈)-聚偏二氟乙烯-聚(丙烯酸-丙烯腈)三嵌段共聚物、聚(丙烯酸-丙烯腈-丙烯酰胺)-聚偏二氟乙烯-聚(丙烯酸-丙烯腈-丙烯酰胺)三嵌段共聚物、聚(丙烯酸-丙烯腈-丙烯酸酯)-聚偏二氟乙烯-聚(丙烯酸-丙烯腈-丙烯酸酯)三嵌段共聚物、聚(丙烯酸-丙烯酰胺)-聚偏二氟乙烯-聚(丙烯酸-丙烯酰胺)三嵌段共聚物、聚(丙烯酸-丙烯腈-丙烯酰胺)-聚偏二氟乙烯-聚(丙烯酸-丙烯腈-丙烯酰胺)三嵌段共聚物中的一种或多种。In some embodiments, the BAB-block copolymer is a polyacrylic acid-polyvinylidene fluoride-polyacrylic acid triblock copolymer, a polyacrylic acid-polyvinyl fluoride-polyacrylic acid triblock copolymer, a polyacrylic acid-polytetrafluoroethylene-polyacrylic acid triblock copolymer, a poly(acrylic acid-acrylate)-polyvinylidene fluoride-poly(acrylic acid-acrylate) triblock copolymer, a poly(acrylic acid-acrylate)-polyvinyl fluoride-poly(acrylic acid-acrylate) triblock copolymer, a poly(acrylic acid-acrylate)-polyvinyl fluoride-poly(acrylic acid-acrylate) triblock copolymer, a poly(acrylic acid-acrylate)-polytetrafluoroethylene-poly(acrylic acid-acrylate) triblock copolymer, block copolymer, poly(acrylic acid-acrylonitrile-acrylate)-polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylate) triblock copolymer, poly(acrylic acid-acrylonitrile-acrylate)-polyvinyl fluoride-poly(acrylic acid-acrylonitrile-acrylate) triblock copolymer, poly(acrylic acid-acrylonitrile-acrylate)-polyvinyl fluoride-poly(acrylic acid-acrylonitrile-acrylate) triblock copolymer, poly(acrylic acid-acrylonitrile-acrylate)-polytetrafluoroethylene-poly(acrylic acid-acrylonitrile-acrylate) triblock copolymer, poly(acrylic acid-acrylamide-acrylate)-polyvinylidene fluoride-poly(acrylic acid-acrylamide-acrylate) triblock copolymer, poly(acrylic acid-acrylamide-acrylate) The invention further comprises one or more of a poly(acrylic acid-acrylamide-acrylate)-polyvinyl fluoride-poly(acrylic acid-acrylamide-acrylate) triblock copolymer, a poly(acrylic acid-acrylamide-acrylate)-polytetrafluoroethylene-poly(acrylic acid-acrylamide-acrylate) triblock copolymer, a poly(acrylic acid-acrylonitrile)-polyvinylidene fluoride-poly(acrylic acid-acrylonitrile) triblock copolymer, a poly(acrylic acid-acrylonitrile-acrylamide)-polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylamide) triblock copolymer, a poly(acrylic acid-acrylonitrile-acrylate)-polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylate) triblock copolymer, a poly(acrylic acid-acrylamide)-polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylate) triblock copolymer, a poly(acrylic acid-acrylamide)-polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylate) triblock copolymer, and a poly(acrylic acid-acrylonitrile-acrylamide)-polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylamide) triblock copolymer.
在一些实施方式中，BAB-嵌段共聚物为聚(偏二氟乙烯-六氟丙烯)-聚(丙烯酸-丙烯酰胺-丙烯酸酯)-聚(偏二氟乙烯-六氟丙烯)三嵌段共聚物、聚氟乙烯-聚丙烯酸-聚氟乙烯、聚四氟乙烯-聚丙烯酸-聚四氟乙烯三嵌段共聚物、聚偏二氟乙烯-聚(丙烯酸-丙烯酸酯)-聚偏二氟乙烯三嵌段共聚物、聚氟乙烯-聚(丙烯酸-丙烯酸酯)-聚氟乙烯三嵌段共聚物、聚四氟乙烯-聚(丙烯酸-丙烯酸酯)-聚四氟乙烯三嵌段共聚物、聚偏二氟乙烯-聚(丙烯酸-丙烯腈-丙烯酸酯)-聚偏二氟乙烯三嵌段共聚物、聚氟乙烯-聚(丙烯酸-丙烯腈-丙烯酸酯)-聚氟乙烯三嵌段共聚物、聚四氟乙烯-聚(丙烯酸-丙烯腈-丙烯酸酯)-聚四氟乙烯三嵌段共聚物、聚偏二氟乙烯-聚(丙烯酸-丙烯酰胺-丙烯酸酯)-聚偏二氟乙烯三嵌段共聚物、聚氟乙烯-聚(丙烯酸-丙烯酰胺-丙烯酸酯)-聚氟乙烯三嵌段共聚物、聚四氟乙烯-聚(丙烯酸-丙烯酰胺-丙烯酸酯)-聚四氟乙烯三嵌段共聚物、聚偏二氟乙烯-聚(丙烯酸-丙烯腈)-聚偏二氟乙烯三嵌段共聚物、聚偏二氟乙烯-聚(丙烯酸-丙烯腈-丙烯酰胺)-聚偏二氟乙烯三嵌段共聚物、聚偏二氟乙烯-聚(丙烯酸-丙烯腈-丙烯酸酯)-聚偏二氟乙烯三嵌段共聚物、聚偏二氟乙烯-聚(丙烯酸-丙烯酰胺)-聚偏二氟乙烯三嵌段共聚物、聚偏二氟乙烯-聚(丙烯酸-丙烯腈-丙烯酰胺)-聚偏二氟乙烯三嵌段共聚物、聚(偏二氟乙烯-六氟丙烯)-聚(丙烯酸-丙烯酰胺-丙烯酸酯)-聚(偏二氟乙烯-六氟丙烯)三嵌段共聚物中的一种 或多种。In some embodiments, the BAB-block copolymer is a poly(vinylidene fluoride-hexafluoropropylene)-poly(acrylic acid-acrylamide-acrylate)-poly(vinylidene fluoride-hexafluoropropylene) triblock copolymer, a polyvinyl fluoride-polyacrylic acid-polyvinyl fluoride, a polytetrafluoroethylene-polyacrylic acid-polytetrafluoroethylene triblock copolymer, a polyvinylidene fluoride-poly(acrylic acid-acrylate)-polyvinylidene fluoride triblock copolymer, a polyvinyl fluoride-poly(acrylic acid-acrylate)-polyvinylidene fluoride triblock copolymer, a polytetrafluoroethylene-poly(acrylic acid-acrylate)-polytetrafluoroethylene triblock copolymer, a polyvinylidene fluoride-poly(acrylic acid-acrylamide-acrylate)-polyvinylidene fluoride triblock copolymer, a polyvinylidene fluoride-poly(acrylic acid-acrylamide-acrylate)-polyvinylidene fluoride triblock copolymer, a polyvinylidene fluoride-poly(acrylic acid-acrylamide-acrylate)-polyvinylidene fluoride triblock copolymer, a polyvinylidene fluoride-poly(acrylic acid-acrylamide-acrylate)-polyvinylidene fluoride triblock copolymer, a polyvinylidene fluoride-poly(acrylic acid-acrylamide-acrylate)-polyvinylidene fluoride triblock copolymer, and a polyvinylidene fluoride-poly(acrylic acid-acrylamide-acrylate)-polyvinylidene fluoride triblock copolymer. The present invention relates to a polyvinylidene fluoride triblock copolymer, a polyvinyl fluoride-poly(acrylic acid-acrylamide-acrylate)-polyvinylidene fluoride triblock copolymer, a polytetrafluoroethylene-poly(acrylic acid-acrylamide-acrylate)-polytetrafluoroethylene triblock copolymer, a polyvinylidene fluoride-poly(acrylic acid-acrylonitrile)-polyvinylidene fluoride triblock copolymer, a polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylamide)-polyvinylidene fluoride triblock copolymer, a polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylate)-polyvinylidene fluoride triblock copolymer, a polyvinylidene fluoride-poly(acrylic acid-acrylamide)-polyvinylidene fluoride triblock copolymer, a polyvinylidene fluoride-poly(acrylic acid-acrylamide-acrylate)-polyvinylidene fluoride triblock copolymer, a polyvinylidene fluoride-poly(acrylic acid-acrylamide-acrylate)-polyvinylidene fluoride triblock copolymer, a polyvinylidene fluoride-poly(acrylic acid-acrylamide-acrylate)-polyvinylidene fluoride triblock copolymer, a polyvinylidene fluoride-poly(acrylic acid-acrylamide-acrylate)-polyvinylidene fluoride triblock copolymer, a polyvinylidene fluoride-hexafluoropropylene triblock copolymer, a poly(vinylidene fluoride-hexafluoropropylene)-poly(acrylic acid-acrylamide-acrylate)-poly(vinylidene fluoride-hexafluoropropylene) triblock copolymer or more.
在本文中，术语“丙烯酸酯”是指丙烯酸及其同系物的酯类的总称。其实例包括但不限于，丙烯酸甲酯、丙烯酸乙酯、甲基丙烯酸甲酯、甲基丙烯酸乙酯等。In this document, the term "acrylate" refers to the general term for esters of acrylic acid and its homologues, examples of which include, but are not limited to, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, and the like.
在一些实施方式中，A-嵌段含有的氟元素与正极活性材料表面及集流体表面的羟基或/和羧基形成氢键作用，使得极片具有优异的粘结力。B-嵌段中的强极性基团羧基可以与正极活性材料表面上的羟基形成强氢键和偶极-偶极相互作用，提高极片的粘结力，提高粘结剂对于浆料中物质的分散性，降低膜片电阻，相比于传统聚偏氟乙烯，可以减少浆料中粘结剂的添加量。另外强极性基团羧基可以增强分子结构的稳定性，可以提高共聚物的玻璃化转变温度，改善共聚物的刚性和的热稳定性，有助于提高正极材料的氧化稳定性，能够大大提升电池的循环性能。In some embodiments, the fluorine element contained in the A-block forms hydrogen bonds with the hydroxyl and/or carboxyl groups on the surface of the positive electrode active material and the current collector, so that the pole piece has excellent adhesion. The strong polar group carboxyl group in the B-block can form strong hydrogen bonds and dipole-dipole interactions with the hydroxyl groups on the surface of the positive electrode active material, thereby improving the adhesion of the pole piece, improving the dispersibility of the binder for the substances in the slurry, and reducing the membrane resistance. Compared with traditional polyvinylidene fluoride, the amount of binder added to the slurry can be reduced. In addition, the strong polar group carboxyl group can enhance the stability of the molecular structure, increase the glass transition temperature of the copolymer, improve the rigidity and thermal stability of the copolymer, help improve the oxidation stability of the positive electrode material, and greatly improve the cycle performance of the battery.
以BAB型嵌段共聚物制备的粘结剂，可以将含氟嵌段和非氟嵌段的重均分子量最大化，充分发挥含氟粘结剂和非氟粘结剂各自的优势，实现优势互补的作用。The binder prepared with the BAB type block copolymer can maximize the weight average molecular weight of the fluorine-containing block and the non-fluorine block, give full play to the respective advantages of the fluorine-containing binder and the non-fluorine binder, and achieve the role of complementary advantages.
综上所述，以BAB型嵌段共聚物制备的粘结剂，能够有效减缓浆料的凝胶现象，提高浆料的稳定性，提高极片的柔性，提高粘结力，降低膜片电阻，降低电池的直流阻抗增长率，和/或提高电池的循环容量保持率。In summary, the binder prepared with BAB type block copolymer can effectively slow down the gelation phenomenon of the slurry, improve the stability of the slurry, improve the flexibility of the electrode, improve the bonding force, reduce the membrane resistance, reduce the DC impedance growth rate of the battery, and/or improve the cycle capacity retention rate of the battery.
在一些实施方式中，B-嵌段含有的氟元素与正极活性材料表面及集流体表面的羟基或/和羧基形成氢键作用，使得极片具有优异的粘结力。A-嵌段中的强极性基团羧基可以与正极活性材料表面上的羟基形成强氢键和偶极-偶极相互作用，提高极片的粘结力，提高粘结剂对于浆料中物质的分散性，降低膜片电阻，相比于传统聚偏氟乙烯，可以减少浆料中粘结剂的添加量。另外强极性基团羧基可以增强分子结构的稳定性，可以提高共聚物的玻璃化转变温度，改善共聚物的刚性和的热稳定性，有助于提高正极材料的氧化稳定性，能够大大提升电 池的循环性能。In some embodiments, the fluorine element contained in the B-block forms hydrogen bonds with the hydroxyl and/or carboxyl groups on the surface of the positive electrode active material and the current collector, so that the pole piece has excellent adhesion. The strong polar group carboxyl group in the A-block can form strong hydrogen bonds and dipole-dipole interactions with the hydroxyl groups on the surface of the positive electrode active material, thereby improving the adhesion of the pole piece, improving the dispersibility of the binder for the substances in the slurry, and reducing the membrane resistance. Compared with traditional polyvinylidene fluoride, the amount of binder added to the slurry can be reduced. In addition, the strong polar group carboxyl group can enhance the stability of the molecular structure, increase the glass transition temperature of the copolymer, improve the rigidity and thermal stability of the copolymer, help improve the oxidation stability of the positive electrode material, and can greatly improve the electrical The circulation performance of the pool.
以BAB型嵌段共聚物制备的粘结剂，可以将含氟嵌段和非氟嵌段的重均分子量最大化，充分发挥含氟粘结剂和非氟粘结剂各自的优势，实现优势互补的作用。The binder prepared with the BAB type block copolymer can maximize the weight average molecular weight of the fluorine-containing block and the non-fluorine block, give full play to the respective advantages of the fluorine-containing binder and the non-fluorine binder, and achieve the role of complementary advantages.
综上所述，以BAB型嵌段共聚物制备的粘结剂，能够有效减缓浆料的凝胶现象，提高浆料的稳定性，提高极片的柔性，提高粘结力，降低膜片电阻，降低电池的直流阻抗增长率，和/或提高电池的循环容量保持率。In summary, the binder prepared with BAB type block copolymer can effectively slow down the gelation phenomenon of the slurry, improve the stability of the slurry, improve the flexibility of the electrode, improve the bonding force, reduce the membrane resistance, reduce the DC impedance growth rate of the battery, and/or improve the cycle capacity retention rate of the battery.
本申请的一个实施方式中，提供一种BAB型嵌段共聚物的制备方法，包括以下步骤：In one embodiment of the present application, a method for preparing a BAB type block copolymer is provided, comprising the following steps:
制备A-嵌段：将至少一种式I所示的单体聚合制备A-嵌段，Preparation of A-block: polymerizing at least one monomer represented by formula I to prepare A-block,
或者将单体单元聚合制备A-嵌段，所述单体单元包括至少一种式II所示的单体，
Alternatively, the A-block is prepared by polymerizing monomer units, wherein the monomer units include at least one monomer represented by formula II,
其中R1、R2、R3各自独立地选自氢、氟、至少含有一个氟原子的C1-3烷基中的一种或多种，R4、R5、R6各自独立地选自氢、取代或未取代的C1-5烷基；wherein R 1 , R 2 , and R 3 are each independently selected from one or more of hydrogen, fluorine, and C 1-3 alkyl containing at least one fluorine atom; and R 4 , R 5 , and R 6 are each independently selected from hydrogen, and substituted or unsubstituted C 1-5 alkyl;
制备B-嵌段：将单体单元聚合制备B-嵌段，所述单体单元包括至少一种式II所示的单体，Preparation of B-block: polymerizing monomer units to prepare B-block, wherein the monomer units include at least one monomer represented by formula II,
或者将至少一种式I所示的单体聚合制备B-嵌段；Alternatively, at least one monomer of formula I is polymerized to prepare a B-block;
制备BAB型嵌段共聚物：将所述A-嵌段和所述B-嵌段接合制备BAB型嵌段共聚物，其中所述A-嵌段和所述B-嵌段含有不同的结构单元。Preparation of a BAB type block copolymer: The A-block and the B-block are joined to prepare a BAB type block copolymer, wherein the A-block and the B-block contain different structural units.
在一些实施方式中，所述单体单元还包括至少一种式III所示的单体，
In some embodiments, the monomer unit further comprises at least one monomer represented by formula III,
其中R7、R8、R9各自独立地选自氢、取代或未取代的C1-5烷基，R10选自酯基、氰基、酰胺基中的一种。R 7 , R 8 and R 9 are each independently selected from hydrogen, substituted or unsubstituted C 1-5 alkyl, and R 10 is selected from one of ester group, cyano group and amide group.
在一些实施方式中，提供一种BAB型嵌段共聚物的制备方法，包括以下步骤：In some embodiments, a method for preparing a BAB type block copolymer is provided, comprising the following steps:
制备A-嵌段：将至少一种式I所示单体聚合制备A-嵌段，Preparation of A-block: polymerizing at least one monomer represented by formula I to prepare A-block,
制备B-嵌段：将至少一种式II所示单体聚合制备B-嵌段，Preparation of B-block: polymerizing at least one monomer represented by formula II to prepare B-block,
制备BAB型嵌段共聚物：将A-嵌段和B-嵌段接合制备BAB型嵌段共聚物，其中A-嵌段和B-嵌段含有不同的结构单元。Preparation of BAB-type block copolymers: A-blocks and B-blocks are joined to prepare BAB-type block copolymers, wherein the A-blocks and the B-blocks contain different structural units.
在一些实施方式中，提供一种BAB型嵌段共聚物的制备方法，包括以下步骤：In some embodiments, a method for preparing a BAB type block copolymer is provided, comprising the following steps:
制备A-嵌段：将至少一种式I所示单体聚合制备A-嵌段，Preparation of A-block: polymerizing at least one monomer represented by formula I to prepare A-block,
制备B-嵌段：将至少一种式II所示单体和至少一种式III所示单体聚合制备B-嵌段，Preparation of B-block: polymerizing at least one monomer represented by formula II and at least one monomer represented by formula III to prepare B-block,
制备BAB型嵌段共聚物：将A-嵌段和B-嵌段接合制备BAB型嵌段共聚物，其中A-嵌段和B-嵌段含有不同的结构单元。Preparation of BAB-type block copolymers: A-blocks and B-blocks are joined to prepare BAB-type block copolymers, wherein the A-blocks and the B-blocks contain different structural units.
在一些实施方式中，提供一种BAB型嵌段共聚物的制备方法，包括以下步骤：In some embodiments, a method for preparing a BAB type block copolymer is provided, comprising the following steps:
制备A-嵌段：将至少一种式II所示单体聚合制备A-嵌段，Preparation of A-block: polymerizing at least one monomer represented by formula II to prepare A-block,
制备B-嵌段：将至少一种式I所示单体聚合制备B-嵌段，Preparation of B-block: polymerizing at least one monomer represented by formula I to prepare B-block,
制备BAB型嵌段共聚物：将A-嵌段和B-嵌段接合制备BAB型嵌段共聚物，其中A-嵌段和B-嵌段含有不同的结构单元。Preparation of BAB-type block copolymers: A-blocks and B-blocks are joined to prepare BAB-type block copolymers, wherein the A-blocks and the B-blocks contain different structural units.
在一些实施方式中，提供一种BAB型嵌段共聚物的制备方法，包括以下步骤：In some embodiments, a method for preparing a BAB type block copolymer is provided, comprising the following steps:
制备A-嵌段：将至少一种式II所示单体和至少一种式III所示单体聚合制备A-嵌段， Preparation of A-block: polymerizing at least one monomer represented by formula II and at least one monomer represented by formula III to prepare A-block,
制备B-嵌段：将至少一种式I所示单体聚合制备B-嵌段，Preparation of B-block: polymerizing at least one monomer represented by formula I to prepare B-block,
制备BAB型嵌段共聚物：将A-嵌段和B-嵌段接合制备BAB型嵌段共聚物，其中A-嵌段和B-嵌段含有不同的结构单元。Preparation of BAB-type block copolymers: A-blocks and B-blocks are joined to prepare BAB-type block copolymers, wherein the A-blocks and the B-blocks contain different structural units.
在一些实施方式中，BAB型嵌段共聚物6的制备方法示意图如图1所示，其中，由式I所示单体或单体单元聚合制备的A-嵌段61的两端基团611为活性基团，由单体单元或式I所示单体聚合制备的B-嵌段62的末端基团621为活性基团，A-嵌段的两端基团611与B-嵌段的末端基团621反应实现聚合物链段的接合，从而制备BAB型嵌段共聚物6。In some embodiments, a schematic diagram of a method for preparing a BAB-type block copolymer 6 is shown in FIG1 , wherein the end groups 611 of an A-block 61 prepared by polymerization of a monomer or monomer unit shown in Formula I are active groups, and the terminal groups 621 of a B-block 62 prepared by polymerization of a monomer unit or a monomer shown in Formula I are active groups, and the end groups 611 of the A-block react with the terminal groups 621 of the B-block to achieve bonding of polymer segments, thereby preparing a BAB-type block copolymer 6.
该制备方法原料便宜，可以降低成本，减少对环境的污染，有利于粘结剂产量的提升。同时该方法制备的粘结剂能够有效减缓浆料的凝胶现象，提高浆料的稳定性，提高极片的柔性，提高粘结力，降低膜片电阻，降低电池的直流阻抗增长率，和/或提高电池的循环容量保持率。The preparation method has cheap raw materials, can reduce costs, reduce environmental pollution, and is conducive to the improvement of binder production. At the same time, the binder prepared by the method can effectively slow down the gelation phenomenon of the slurry, improve the stability of the slurry, improve the flexibility of the pole piece, improve the bonding force, reduce the membrane resistance, reduce the DC impedance growth rate of the battery, and/or improve the cycle capacity retention rate of the battery.
在一些实施方式中，制备A-嵌段的方法包括：In some embodiments, the method of preparing the A-block comprises:
将至少一种式I所示单体或单体单元、第二引发剂在80-95℃的反应温度下聚合反应2.5-5小时，对产物的端基进行取代反应，制备两端均具有叠氮基团或炔基作为端基的所述A-嵌段。At least one monomer or monomer unit represented by formula I and a second initiator are polymerized at a reaction temperature of 80-95° C. for 2.5-5 hours, and the terminal groups of the product are substituted to prepare the A-block having azide groups or alkynyl groups as terminal groups at both ends.
在本文中，术语“叠氮基团”是指-N3基团。As used herein, the term "azide group" refers to a -N3 group.
在本文中，术语“炔基”是指-C≡C基团。As used herein, the term "alkynyl" refers to a -C≡C group.
在一些实施方式中，制备A-嵌段的方法包括：In some embodiments, the method of preparing the A-block comprises:
将至少一种式I所示单体、第二引发剂在80-95℃的反应温度下聚合反应2.5-5小时，对产物的端基进行取代反应，制备两端均具有叠氮基团或炔基作为端基的所述A-嵌段。At least one monomer represented by formula I and a second initiator are polymerized at a reaction temperature of 80-95° C. for 2.5-5 hours, and the terminal groups of the products are substituted to prepare the A-block having azide groups or alkynyl groups as terminal groups at both ends.
在一些实施方式中，A-嵌段的合成路线如下所示，在第二引发剂的作用下，式I所示单体发生聚合反应，生成A-嵌段。由于第二引发剂两侧的端基为卤素取代的烷基或三甲基硅基乙炔基团，A-嵌段两侧的卤素或三甲基硅基容易被取代，使得A-嵌段两端均具有叠氮基团 或炔基。
In some embodiments, the synthesis route of the A-block is as follows: under the action of the second initiator, the monomer shown in Formula I undergoes a polymerization reaction to generate the A-block. Since the terminal groups on both sides of the second initiator are halogen-substituted alkyl or trimethylsilyl acetylene groups, the halogen or trimethylsilyl groups on both sides of the A-block are easily substituted, so that both ends of the A-block have azide groups. or alkynyl.
采用该制备方法制备出的叠氮化物封端的A-嵌段，便于A-嵌段以高效温和的方式与B-嵌段发生嵌段间的连接，生成BAB型嵌段共聚物。The azide-terminated A-block prepared by the preparation method facilitates the A-block to be connected with the B-block in an efficient and mild manner to generate a BAB-type block copolymer.
在一些实施方式中，将至少一种单体单元、第二引发剂在80-95℃的反应温度下聚合反应2.5-5小时，对产物的端基进行取代反应，制备两端均具有叠氮基团或炔基作为端基的所述A-嵌段。In some embodiments, at least one monomer unit and a second initiator are polymerized at a reaction temperature of 80-95° C. for 2.5-5 hours, and the end groups of the product are subjected to a substitution reaction to prepare the A-block having azide groups or alkynyl groups as end groups at both ends.
在一些实施方式中，A-嵌段的合成路线如下所示，在第二引发剂的作用下，单体单元发生聚合反应，生成A-嵌段。由于第二引发剂两侧的端基为卤素取代的烷基或三甲基硅基乙炔基团，A-嵌段两侧的卤素或三甲基硅基容易被取代，使得A-嵌段两端均具有叠氮基团或炔基。其中x为衍生自式II所示单体的结构单元的聚合度，y为衍生自式III所示单体的结构单元的聚合度，x为大于零的正整数，y可以为零或大于零的正整数。当A-嵌段中含有衍生自式II所示单体的结构单元和衍生自式III所示单体的结构单元，A-嵌段可以为无规共聚物、嵌段共聚物或交替共聚物。
In some embodiments, the synthesis route of the A-block is as follows, and under the action of the second initiator, the monomer unit undergoes a polymerization reaction to generate the A-block. Since the end groups on both sides of the second initiator are halogen-substituted alkyl or trimethylsilyl acetylene groups, the halogen or trimethylsilyl groups on both sides of the A-block are easily substituted, so that both ends of the A-block have an azide group or an alkynyl group. Wherein x is the degree of polymerization of the structural unit derived from the monomer shown in formula II, y is the degree of polymerization of the structural unit derived from the monomer shown in formula III, x is a positive integer greater than zero, and y can be zero or a positive integer greater than zero. When the A-block contains structural units derived from the monomer shown in formula II and structural units derived from the monomer shown in formula III, the A-block can be a random copolymer, a block copolymer or an alternating copolymer.
在一些实施方式中，制备B-嵌段的方法包括：In some embodiments, the method of preparing the B-block comprises:
将至少一种式I所示单体或者所述单体单元、链转移剂和第一引发剂在60-80℃的反应温度下通过可逆加成-裂解链转移聚合，反应4.5-7小时，得到末端具有炔基或叠氮基团作为端基的所述B-嵌段。At least one monomer or monomer unit of formula I, a chain transfer agent and a first initiator are subjected to reversible addition-fragmentation chain transfer polymerization at a reaction temperature of 60-80° C. for 4.5-7 hours to obtain the B-block having an alkynyl or azide group as an end group.
在本文中，术语“可逆加成-裂解链转移聚合”(RAFT聚合)是一种可逆失活自由基聚合，也被称为“活性”/可控自由基聚合方法。RAFT聚合的主要原理是通过在自由基聚合中加入作为链转移试剂的RAFT试剂，将易终止的自由基通过链转移的方式保护起来使得聚合反应中大多数自由基转变为休眠种自由基，在反应过程中休眠链段与活性链段同时存在并通过动态可逆的反应不断进行快速的相互切换，从而导致在任一时刻只有少数的聚合物链以活性链形式存在并进行增长最终使得每条聚合物链段的增长几率大致相等进而表现出活性聚合的特征。In this article, the term "reversible addition-fragmentation chain transfer polymerization" (RAFT polymerization) is a type of reversibly deactivated free radical polymerization, also known as a "living"/controlled free radical polymerization method. The main principle of RAFT polymerization is to add a RAFT agent as a chain transfer agent to the free radical polymerization, and protect the easily terminated free radicals through chain transfer, so that most of the free radicals in the polymerization reaction are converted into dormant free radicals. During the reaction, dormant segments and active segments exist at the same time and are constantly and rapidly switched with each other through dynamic reversible reactions, resulting in only a few polymer chains existing in the form of active chains and growing at any one time, which ultimately makes the growth probability of each polymer segment roughly equal, thus showing the characteristics of living polymerization.
将所述单体单元、链转移剂和第一引发剂在60-80℃的反应温度下通过可逆加成-裂解链转移聚合，反应4.5-7小时，得到末端具有炔基或叠氮基团作为端基的所述B-嵌段。The monomer unit, chain transfer agent and first initiator are polymerized by reversible addition-fragmentation chain transfer at a reaction temperature of 60-80° C. for 4.5-7 hours to obtain the B-block having an alkynyl group or an azide group as a terminal group.
在一些实施方式中，B-嵌段的合成路线如下所示，其中，链转移剂为三硫代碳酸酯，Z’为末端含有炔基或叠氮基团的活性基团，R为烷基。通过下述反应，制备了末端具有炔基或叠氮基团的B-嵌段，其中m为衍生自式II所示单体的结构单元的聚合度，n为衍生自式III所示单体的结构单元的聚合度，m为大于零的正整数，n可以为零或 大于零的正整数。当B-嵌段中含有衍生自式II所示单体的结构单元和衍生自式III所示单体的结构单元，B-嵌段可以为无规共聚物、嵌段共聚物或交替共聚物。
In some embodiments, the synthesis route of the B-block is as follows, wherein the chain transfer agent is trithiocarbonate, Z' is an active group containing an alkynyl or azide group at the end, and R is an alkyl group. The B-block having an alkynyl or azide group at the end is prepared by the following reaction, wherein m is the degree of polymerization of the structural unit derived from the monomer represented by formula II, n is the degree of polymerization of the structural unit derived from the monomer represented by formula III, m is a positive integer greater than zero, and n can be zero or A positive integer greater than 0. When the B-block contains a structural unit derived from the monomer represented by formula II and a structural unit derived from the monomer represented by formula III, the B-block may be a random copolymer, a block copolymer or an alternating copolymer.
在本文中，术语“无规共聚物”是指无序共聚物，由两种或多种单体经共聚反应生成排列无序的产物。As used herein, the term "random copolymer" refers to a disordered copolymer formed by copolymerization of two or more monomers.
在本文中，术语“交替共聚物”是指在聚合链中，两种或两种以上的结构单元相互交替排列而构成的共聚物。As used herein, the term "alternating copolymer" refers to a copolymer in which two or more structural units are arranged alternately in a polymer chain.
在一些实施方式中，制备B-嵌段的方法包括：In some embodiments, the method of preparing the B-block comprises:
将至少一种式I所示单体、链转移剂和第二引发剂在60-80℃的反应温度下通过可逆加成-裂解链转移聚合，反应4.5-7h得到末端具有炔基或叠氮基团的B-嵌段。At least one monomer of formula I, a chain transfer agent and a second initiator are polymerized by reversible addition-fragmentation chain transfer at a reaction temperature of 60-80° C. for 4.5-7 hours to obtain a B-block having an alkynyl or azide group at the end.
在一些实施方式中，B-嵌段的合成路线示意图如下图所示，其中，链转移剂为三硫代碳酸酯，Z’为末端含有炔基或叠氮基团的活性基团，R为烷基。通过下述反应，制备了末端具有炔基或叠氮基团的B-嵌段。
In some embodiments, the synthesis route of the B-block is shown in the figure below, wherein the chain transfer agent is trithiocarbonate, Z' is an active group having an alkynyl or azide group at the end, and R is an alkyl group. The B-block having an alkynyl or azide group at the end is prepared by the following reaction.
采用可逆加成-裂解链转移聚合，可实现可控聚合，且产物分子量分布较窄。而且通过上述反应，B-嵌段只在末端具有炔基或叠氮基团，方便以高效温和的方式定向的与A-嵌段发生接合，生成BAB型三嵌 段共聚物。The reversible addition-fragmentation chain transfer polymerization can achieve controllable polymerization, and the molecular weight distribution of the product is relatively narrow. Moreover, through the above reaction, the B-block only has an alkynyl or azide group at the end, which is convenient for directing the bonding with the A-block in an efficient and gentle manner to generate a BAB-type triblock. Block copolymer.
在一些实施方式中，制备BAB型嵌段共聚物的方法包括：In some embodiments, the method of preparing a BAB-type block copolymer comprises:
将两端均具有叠氮基团或炔基作为端基的所述A-嵌段与末端具有炔基或叠氮基团作为端基的所述B-嵌段混合，进行点击反应，制备BAB型嵌段共聚物，其中所述A-嵌段和所述B-嵌段的端基不同。The A-block having an azide group or an alkynyl group as an end group at both ends is mixed with the B-block having an alkynyl group or an azide group as an end group at the end, and a click reaction is performed to prepare a BAB type block copolymer, wherein the end groups of the A-block and the B-block are different.
在本文中，术语“点击反应”是指炔基与叠氮基发生环加成反应，使得A-嵌段与B-嵌段相连的反应。在一些实施方式中，点击反应在Cu(I)催化剂的存在下，常温常压下进行。Herein, the term "click reaction" refers to a cycloaddition reaction between an alkynyl group and an azide group, so that the A-block is connected to the B-block. In some embodiments, the click reaction is carried out in the presence of a Cu(I) catalyst at room temperature and pressure.
在一些实施方式中，A-嵌段的端基为叠氮基团，B-嵌段的端基为炔基。In some embodiments, the terminal group of the A-block is an azide group and the terminal group of the B-block is an alkynyl group.
在一些实施方式中，A-嵌段的端基为炔基，B-嵌段的端基为叠氮基团。In some embodiments, the terminal group of the A-block is an alkynyl group and the terminal group of the B-block is an azide group.
上述制备方法，具有产率高、副产物无害、反应条件简单温和、反应原料易得的优点，能够实现嵌段聚合物的可控聚合，有利于提高产品的良品率。The above preparation method has the advantages of high yield, harmless by-products, simple and mild reaction conditions, and readily available reaction raw materials. It can achieve controlled polymerization of block polymers, which is beneficial to improving the yield rate of products.
在一些实施方式中，链转移剂为含末端炔基或叠氮基团的RAFT链转移剂。在一些实施方式中，链转移剂为含末端炔基或叠氮基团的三硫代碳酸酯。在一些实施方式中，链转移剂的结构式选自下式，
In some embodiments, the chain transfer agent is a RAFT chain transfer agent containing a terminal alkynyl or azide group. In some embodiments, the chain transfer agent is a trithiocarbonate containing a terminal alkynyl or azide group. In some embodiments, the structural formula of the chain transfer agent is selected from the following formula,
含末端炔基或叠氮基团的RAFT链转移剂在B-嵌段合成的同时使得B-嵌段的末端带有炔基或叠氮基团，为B-嵌段与A-嵌段发生点 击反应提供了基础，避免了复杂的后处理步骤，能够提高反应效率。The RAFT chain transfer agent containing terminal alkynyl or azide groups makes the terminal of B-block carry alkynyl or azide groups during the synthesis of B-block, which is the point of occurrence of B-block and A-block. It provides a basis for the knock-in reaction, avoids complicated post-processing steps, and can improve the reaction efficiency.
在一些实施方式中，第一引发剂为偶氮引发剂，选自偶氮二异丁腈，偶氮二异庚腈的一种或多种。偶氮引发剂是一种常用的自由基聚合引发剂，易于分解形成自由基，便于引发自由基聚合。In some embodiments, the first initiator is an azo initiator selected from one or more of azobisisobutyronitrile and azobisisoheptanenitrile. Azo initiator is a commonly used free radical polymerization initiator, which is easy to decompose to form free radicals, and is convenient for initiating free radical polymerization.
在一些实施方式中，第二引发剂为对称型双官能度引发剂，选自4-(氯甲基)过氧化苯甲酰。对称型双官能度引发剂使得A-嵌段两侧能够对称地带有相同的活性官能团，有助于A-嵌段两侧端基叠氮化或炔化的同时实现。In some embodiments, the second initiator is a symmetrical bifunctional initiator selected from 4-(chloromethyl)benzoyl peroxide. The symmetrical bifunctional initiator allows both sides of the A-block to symmetrically carry the same active functional groups, which helps to achieve simultaneous azidation or alkyneation of the terminal groups on both sides of the A-block.
在一些实施方式中，BAB型嵌段共聚物可以应用在二次电池中，可选地，所述二次电池包括锂离子电池、钠离子电池、镁离子电池、钾离子电池中的至少一种。In some embodiments, the BAB type block copolymer may be used in a secondary battery. Optionally, the secondary battery includes at least one of a lithium ion battery, a sodium ion battery, a magnesium ion battery, and a potassium ion battery.
[正极极片][Positive electrode]
正极极片包括正极集流体以及设置在正极集流体至少一个表面的正极膜层，所述正极膜层包括正极活性物质、导电剂和粘结剂，该粘结剂为一些实施方式中的BAB型嵌段共聚物或一些实施方式中的制备方法制备的BAB型嵌段共聚物。The positive electrode plate includes a positive electrode current collector and a positive electrode film layer arranged on at least one surface of the positive electrode current collector, wherein the positive electrode film layer includes a positive electrode active material, a conductive agent and a binder, wherein the binder is a BAB type block copolymer in some embodiments or a BAB type block copolymer prepared by a preparation method in some embodiments.
该正极极片具有优异的柔韧性、粘结力和/或较低的膜片电阻。The positive electrode sheet has excellent flexibility, adhesion and/or low film resistance.
在一些实施方式中，粘结剂的质量分数为0.1％-3％，基于正极活性物质的总质量计。在一些实施方式中，粘结剂的质量分数可选为0.1％-0.2％、0.1％-1％、0.1％-1.2％、0.2％-1％、0.2％-1.2％、0.2％-3％、1％-1.2％、1％-3％、1.2％-3％中的任意一种，基于正极活性物质的总质量计。In some embodiments, the mass fraction of the binder is 0.1%-3%, based on the total mass of the positive electrode active material. In some embodiments, the mass fraction of the binder can be selected from any one of 0.1%-0.2%, 0.1%-1%, 0.1%-1.2%, 0.2%-1%, 0.2%-1.2%, 0.2%-3%, 1%-1.2%, 1%-3%, 1.2%-3%, based on the total mass of the positive electrode active material.
当粘结剂含量过低时，粘结剂无法发挥足够的粘结效果。一方面粘结剂无法充分分散导电剂和活性物质，导致极片的膜片电阻升高；另一方面浆料中的正极活性物质和导电剂无法与粘结剂紧密结合，正极活性物质和导电剂颗粒沉降及团聚，浆料的稳定性下降。When the binder content is too low, the binder cannot exert sufficient bonding effect. On the one hand, the binder cannot fully disperse the conductive agent and active material, resulting in an increase in the film resistance of the electrode; on the other hand, the positive electrode active material and conductive agent in the slurry cannot be tightly combined with the binder, and the positive electrode active material and conductive agent particles settle and agglomerate, and the stability of the slurry decreases.
相反，粘结剂含量过高时，浆料的粘度过大，会导致包覆于正极活性物质表面的粘结剂包覆层过厚，在电池循环过程中影响电子和离 子的传输，膜片内阻增大。On the contrary, when the binder content is too high, the viscosity of the slurry is too high, which will cause the binder coating on the surface of the positive electrode active material to be too thick, affecting the electron and ion bonding during the battery cycle. The transmission of electrons increases and the internal resistance of the diaphragm increases.
控制粘结剂的质量分数在合理范围内，能够显著减缓浆料的凝胶现象，提高浆料稳定性，提高极片的柔性，并提高电池的循环容量保持率。Controlling the mass fraction of the binder within a reasonable range can significantly slow down the gelation of the slurry, improve the stability of the slurry, increase the flexibility of the electrode, and improve the cycle capacity retention rate of the battery.
在一些实施方式中，所述正极膜层与所述正极集流体间单位长度的粘结力不小于8N/m。在一些实施方式中，所述正极膜层与所述正极集流体间单位长度的粘结力不小于10N/m。In some embodiments, the bonding force per unit length between the positive electrode film layer and the positive electrode current collector is not less than 8 N/m. In some embodiments, the bonding force per unit length between the positive electrode film layer and the positive electrode current collector is not less than 10 N/m.
正极膜层与正极集流体间单位长度的粘结力可以采用本领域公知的任意手段进行测试，如参照GB-T2790-1995国标《胶粘剂180°剥离强度实验方法》进行测试。作为示例，将正极极片裁剪为20mm×100mm尺寸的测试试样，备用；极片用双面胶粘接正极膜层一面，并用压辊压实，使双面胶与极片完全贴合；双面胶的另外一面粘贴于不锈钢表面，将试样一端反向弯曲，弯曲角度为180°；采用高铁拉力机测试，将不锈钢一端固定于拉力机下方夹具，试样弯曲末端固定于上方夹具，调整试样角度，保证上下端位于垂直位置，然后以50mm/min的速度拉伸试样，直到正极集流体全部从正极膜片剥离，记录过程中的位移和作用力。以受力平衡时的力除以与双面胶贴合的极片的宽度(极片的宽度方向垂直于剥离方向)做为单位长度的极片的粘结力，本测试中极片的宽度为20mm。The bonding force per unit length between the positive electrode film layer and the positive electrode current collector can be tested by any means known in the art, such as testing with reference to GB-T2790-1995 national standard "Adhesive 180° Peel Strength Test Method". As an example, the positive electrode sheet is cut into a test sample of 20mm×100mm size for standby use; the electrode sheet is bonded to one side of the positive electrode film layer with double-sided tape, and compacted with a roller to make the double-sided tape and the electrode sheet completely fit; the other side of the double-sided tape is attached to the stainless steel surface, and one end of the sample is bent in the opposite direction with a bending angle of 180°; the high-speed rail tensile machine is used for testing, one end of the stainless steel is fixed to the lower fixture of the tensile machine, the bent end of the sample is fixed to the upper fixture, the angle of the sample is adjusted to ensure that the upper and lower ends are in a vertical position, and then the sample is stretched at a speed of 50mm/min until the positive electrode current collector is completely peeled off from the positive electrode film, and the displacement and force during the process are recorded. The force when the force is balanced divided by the width of the electrode attached to the double-sided tape (the width direction of the electrode is perpendicular to the peeling direction) is taken as the bonding force of the electrode per unit length. In this test, the width of the electrode is 20mm.
该极片的正极膜层与正极集流体之间具有高的粘结强度，在使用过程中，正极膜层不容易从正极集流体上脱落，有助于提高电池的循环性能和安全性。The positive electrode film layer of the pole piece has high bonding strength with the positive electrode current collector. During use, the positive electrode film layer is not easy to fall off from the positive electrode current collector, which helps to improve the cycle performance and safety of the battery.
在一些实施方式中，所述正极极片在经过不少于3次的弯折测试后，所述正极极片出现透光现象。In some embodiments, after the positive electrode plate has been subjected to no less than three bending tests, the positive electrode plate becomes light-transmissive.
弯折测试，也称为柔韧性测试，可以用于测试极片的柔韧性，该测试可以采用本领域公知的任意手段进行。作为示例，将冷压后的正极极片裁剪为20mm×100mm尺寸的测试试样；将其正向对折后，用2kg压辊压平，并展开对着光检查缝隙是否出现透光，如未出现透光， 则反向对折，用2kg压辊压平，并对着光再次检查，如此反复直至，缝隙出现透光现象，记录对折次数；取至少三个式样进行测试，并取平均值，作为弯折测试的测试结果。The bending test, also known as the flexibility test, can be used to test the flexibility of the electrode. The test can be performed by any means known in the art. As an example, the cold-pressed positive electrode is cut into a test specimen of 20mm×100mm in size; it is folded in half, flattened with a 2kg roller, and unfolded to check whether there is light transmission through the gap. If no light is transmitted, Then fold it in the opposite direction, flatten it with a 2kg roller, and check it again against the light. Repeat this process until light is translucent through the gap and record the number of folds. Take at least three samples for testing and take the average value as the test result of the bending test.
极片能经过不少于3次的弯折测试，表明极片具有良好的柔韧性，不易在生产过程中出现极片崩裂、使用过程中出现极片脆断的现象，有助于提高电池的良品率，提高电池的安全性能。The electrode can undergo no less than 3 bending tests, indicating that the electrode has good flexibility and is not prone to cracking during the production process or brittle breakage during use, which helps to improve the yield rate of the battery and improve the safety performance of the battery.
在一些实施方式中，所述正极极片的膜片电阻≤0.52Ω。在一些实施方式中，所述正极极片的膜片电阻≤0.46Ω。In some embodiments, the sheet resistance of the positive electrode sheet is ≤0.52Ω. In some embodiments, the sheet resistance of the positive electrode sheet is ≤0.46Ω.
膜片电阻测试可以用于测试极片的电阻，该测试可以采用本领域公知的任意手段进行。作为示例，将极片左、中、右处裁剪直径20mm的小圆片；打开元能科技极片电阻仪指示灯，将置于膜片电阻仪“探头”合适位置，点击“开始”按钮，待示数稳定，读取即可；每个小圆片测试两个位置，最后计算六次测量的平均值，即为该极片的膜片电阻。The diaphragm resistance test can be used to test the resistance of the electrode. The test can be performed by any means known in the art. As an example, cut small discs with a diameter of 20 mm from the left, middle, and right sides of the electrode; turn on the indicator light of the Yuanneng Technology electrode resistance meter, place the probe in the appropriate position of the diaphragm resistance meter, click the "start" button, wait for the reading to stabilize, and then read it; test two positions of each small disc, and finally calculate the average of six measurements, which is the diaphragm resistance of the electrode.
作为示例，正极集流体具有在其自身厚度方向相对的两个表面，正极膜层设置在正极集流体相对的两个表面的其中任意一者或两者上。As an example, the positive electrode current collector has two surfaces opposite to each other in its thickness direction, and the positive electrode film layer is disposed on any one or both of the two opposite surfaces of the positive electrode current collector.
在一些实施方式中，所述正极集流体可采用金属箔片或复合集流体。例如，作为金属箔片，可采用铝箔。复合集流体可包括高分子材料基层和形成于高分子材料基层至少一个表面上的金属层。复合集流体可通过将金属材料(铝、铝合金、镍、镍合金、钛、钛合金、银及银合金等)形成在高分子材料基材(如聚丙烯(PP)、聚对苯二甲酸乙二醇酯(PET)、聚对苯二甲酸丁二醇酯(PBT)、聚苯乙烯(PS)、聚乙烯(PE)等的基材)上而形成。In some embodiments, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum foil may be used. The composite current collector may include a polymer material base and a metal layer formed on at least one surface of the polymer material base. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).
在一些实施方式中，正极活性材料可采用本领域公知的用于电池的正极活性材料。作为示例，正极活性材料可包括以下材料中的至少一种：橄榄石结构的含锂磷酸盐、锂过渡金属氧化物及其各自的改性化合物。但本申请并不限定于这些材料，还可以使用其他可被用作电池正极活性材料的传统材料。这些正极活性材料可以仅单独使用一种， 也可以将两种以上组合使用。其中，锂过渡金属氧化物的示例可包括但不限于锂钴氧化物(如LiCoO2)、锂镍氧化物(如LiNiO2)、锂锰氧化物(如LiMnO2、LiMn2O4)、锂镍钴氧化物、锂锰钴氧化物、锂镍锰氧化物、锂镍钴锰氧化物(如LiNi1/3Co1/3Mn1/3O2(也可以简称为NCM333)、LiNi0.5Co0.2Mn0.3O2(也可以简称为NCM523)、LiNi0.5Co0.25Mn0.25O2(也可以简称为NCM211)、LiNi0.6Co0.2Mn0.2O2(也可以简称为NCM622)、LiNi0.8Co0.1Mn0.1O2(也可以简称为NCM811)、锂镍钴铝氧化物(如LiNi0.85Co0.15Al0.05O2)及其改性化合物等中的至少一种。橄榄石结构的含锂磷酸盐的示例可包括但不限于磷酸铁锂(如LiFePO4(也可以简称为LFP))、磷酸铁锂与碳的复合材料、磷酸锰锂(如LiMnPO4)、磷酸锰锂与碳的复合材料、磷酸锰铁锂、磷酸锰铁锂与碳的复合材料中的至少一种。In some embodiments, the positive electrode active material may be a positive electrode active material for a battery known in the art. As an example, the positive electrode active material may include at least one of the following materials: an olivine-structured lithium-containing phosphate, a lithium transition metal oxide, and their respective modified compounds. However, the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone, Two or more kinds may be used in combination. Among them, examples of lithium transition metal oxides may include, but are not limited to , lithium cobalt oxide (such as LiCoO2 ), lithium nickel oxide (such as LiNiO2 ), lithium manganese oxide (such as LiMnO2 , LiMn2O4 ), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi1 / 3Co1 / 3Mn1 / 3O2 (also referred to as NCM333 ), LiNi0.5Co0.2Mn0.3O2 (also referred to as NCM523 ) , LiNi0.5Co0.25Mn0.25O2 (also referred to as NCM211 ) , LiNi0.6Co0.2Mn0.2O2 (also referred to as NCM622 ), LiNi0.8Co0.1Mn0.1O2 (also referred to as NCM811 ), lithium nickel cobalt aluminum oxide ( such as LiNi 0.85 Co 0.15 Al 0.05 O 2 ) and at least one of modified compounds thereof. Examples of lithium-containing phosphates with an olivine structure may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO 4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO 4 ), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon.
在一些实施方式中，正极膜层还可选地包括导电剂。作为示例，所述导电剂可以包括超导碳、乙炔黑、炭黑、科琴黑、碳点、碳纳米管、石墨烯及碳纳米纤维中的至少一种。In some embodiments, the positive electrode film layer may further include a conductive agent, which may include, for example, at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.
在一些实施方式中，可以通过以下方式制备正极极片：将上述用于制备正极极片的组分，例如正极活性材料、导电剂、粘结剂和任意其他的组分分散于溶剂(例如N-甲基吡咯烷酮)中，形成正极浆料；将正极浆料涂覆在正极集流体上，经烘干、冷压等工序后，即可得到正极极片。In some embodiments, the positive electrode sheet can be prepared in the following manner: the components for preparing the positive electrode sheet, such as the positive electrode active material, the conductive agent, the binder and any other components are dispersed in a solvent (such as N-methylpyrrolidone) to form a positive electrode slurry; the positive electrode slurry is coated on the positive electrode collector, and after drying, cold pressing and other processes, the positive electrode sheet can be obtained.
[负极极片][Negative electrode]
负极极片包括负极集流体以及设置在负极集流体至少一个表面上的负极膜层，所述负极膜层包括负极活性材料。The negative electrode sheet includes a negative electrode current collector and a negative electrode film layer disposed on at least one surface of the negative electrode current collector, wherein the negative electrode film layer includes a negative electrode active material.
作为示例，负极集流体具有在其自身厚度方向相对的两个表面，负极膜层设置在负极集流体相对的两个表面中的任意一者或两者上。As an example, the negative electrode current collector has two surfaces opposite to each other in its thickness direction, and the negative electrode film layer is disposed on any one or both of the two opposite surfaces of the negative electrode current collector.
在一些实施方式中，所述负极集流体可采用金属箔片或复合集流体。例如，作为金属箔片，可以采用铜箔。复合集流体可包括高分子材料基层和形成于高分子材料基材至少一个表面上的金属层。复合集 流体可通过将金属材料(铜、铜合金、镍、镍合金、钛、钛合金、银及银合金等)形成在高分子材料基材(如聚丙烯(PP)、聚对苯二甲酸乙二醇酯(PET)、聚对苯二甲酸丁二醇酯(PBT)、聚苯乙烯(PS)、聚乙烯(PE)等的基材)上而形成。In some embodiments, the negative electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, a copper foil may be used. The composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer. The fluid can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).
在一些实施方式中，负极活性材料可采用本领域公知的用于电池的负极活性材料。作为示例，负极活性材料可包括以下材料中的至少一种：人造石墨、天然石墨、软炭、硬炭、硅基材料、锡基材料和钛酸锂等。所述硅基材料可选自单质硅、硅氧化合物、硅碳复合物、硅氮复合物以及硅合金中的至少一种。所述锡基材料可选自单质锡、锡氧化合物以及锡合金中的至少一种。但本申请并不限定于这些材料，还可以使用其他可被用作电池负极活性材料的传统材料。这些负极活性材料可以仅单独使用一种，也可以将两种以上组合使用。In some embodiments, the negative electrode active material may adopt the negative electrode active material for the battery known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.
在一些实施方式中，负极膜层还可选地包括粘结剂。所述粘结剂可选自丁苯橡胶(SBR)、聚丙烯酸(PAA)、聚丙烯酸钠(PAAS)、聚丙烯酰胺(PAM)、聚乙烯醇(PVA)、海藻酸钠(SA)、聚甲基丙烯酸(PMAA)及羧甲基壳聚糖(CMCS)中的至少一种。In some embodiments, the negative electrode film layer may further include a binder. The binder may be selected from at least one of styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA) and carboxymethyl chitosan (CMCS).
在一些实施方式中，负极膜层还可选地包括导电剂。导电剂可选自超导碳、乙炔黑、炭黑、科琴黑、碳点、碳纳米管、石墨烯及碳纳米纤维中的至少一种。In some embodiments, the negative electrode film layer may further include a conductive agent, which may be selected from at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.
在一些实施方式中，负极膜层还可选地包括其他助剂，例如增稠剂(如羧甲基纤维素钠(CMC-Na))等。In some embodiments, the negative electrode film layer may optionally include other additives, such as a thickener (eg, sodium carboxymethyl cellulose (CMC-Na)).
在一些实施方式中，可以通过以下方式制备负极极片：将上述用于制备负极极片的组分，例如负极活性材料、导电剂、粘结剂和任意其他组分分散于溶剂(例如去离子水)中，形成负极浆料；将负极浆料涂覆在负极集流体上，经烘干、冷压等工序后，即可得到负极极片。In some embodiments, the negative electrode sheet can be prepared in the following manner: the components for preparing the negative electrode sheet, such as the negative electrode active material, the conductive agent, the binder and any other components are dispersed in a solvent (such as deionized water) to form a negative electrode slurry; the negative electrode slurry is coated on the negative electrode collector, and after drying, cold pressing and other processes, the negative electrode sheet can be obtained.
[电解质][Electrolytes]
电解质在正极极片和负极极片之间起到传导离子的作用。本申请对电解质的种类没有具体的限制，可根据需求进行选择。例如，电解 质可以是液态的、凝胶态的或全固态的。The electrolyte plays the role of conducting ions between the positive electrode and the negative electrode. The present application has no specific restrictions on the type of electrolyte, which can be selected according to needs. The substance can be liquid, gel or completely solid.
在一些实施方式中，所述电解质采用电解液。所述电解液包括电解质盐和溶剂。In some embodiments, the electrolyte is an electrolyte solution, which includes an electrolyte salt and a solvent.
在一些实施方式中，电解质盐可选自六氟磷酸锂、四氟硼酸锂、高氯酸锂、六氟砷酸锂、双氟磺酰亚胺锂、双三氟甲磺酰亚胺锂、三氟甲磺酸锂、二氟磷酸锂、二氟草酸硼酸锂、二草酸硼酸锂、二氟二草酸磷酸锂及四氟草酸磷酸锂中的至少一种。In some embodiments, the electrolyte salt can be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.
在一些实施方式中，溶剂可选自碳酸亚乙酯、碳酸亚丙酯、碳酸甲乙酯、碳酸二乙酯、碳酸二甲酯、碳酸二丙酯、碳酸甲丙酯、碳酸乙丙酯、碳酸亚丁酯、氟代碳酸亚乙酯、甲酸甲酯、乙酸甲酯、乙酸乙酯、乙酸丙酯、丙酸甲酯、丙酸乙酯、丙酸丙酯、丁酸甲酯、丁酸乙酯、1,4-丁内酯、环丁砜、二甲砜、甲乙砜及二乙砜中的至少一种。In some embodiments, the solvent can be selected from at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclopentane sulfone, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone.
在一些实施方式中，所述电解液还可选地包括添加剂。例如添加剂可以包括负极成膜添加剂、正极成膜添加剂，还可以包括能够改善电池某些性能的添加剂，例如改善电池过充性能的添加剂、改善电池高温或低温性能的添加剂等。In some embodiments, the electrolyte may further include additives, such as negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain battery properties, such as additives that improve battery overcharge performance, additives that improve battery high or low temperature performance, etc.
[隔离膜][Isolation film]
在一些实施方式中，二次电池中还包括隔离膜。本申请对隔离膜的种类没有特别的限制，可以选用任意公知的具有良好的化学稳定性和机械稳定性的多孔结构隔离膜。In some embodiments, the secondary battery further includes a separator. The present application has no particular limitation on the type of separator, and any known porous separator with good chemical stability and mechanical stability can be selected.
在一些实施方式中，隔离膜的材质可选自玻璃纤维、无纺布、聚乙烯、聚丙烯及聚偏二氟乙烯中的至少一种。隔离膜可以是单层薄膜，也可以是多层复合薄膜，没有特别限制。在隔离膜为多层复合薄膜时，各层的材料可以相同或不同，没有特别限制。In some embodiments, the material of the isolation membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride. The isolation membrane can be a single-layer film or a multi-layer composite film, without particular limitation. When the isolation membrane is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation.
在一些实施方式中，正极极片、负极极片和隔离膜可通过卷绕工艺或叠片工艺制成电极组件。In some embodiments, the positive electrode sheet, the negative electrode sheet, and the separator may be formed into an electrode assembly by a winding process or a lamination process.
在一些实施方式中，二次电池可包括外包装。该外包装可用于封装上述电极组件及电解质。 In some embodiments, the secondary battery may include an outer package, which may be used to encapsulate the electrode assembly and the electrolyte.
在一些实施方式中，二次电池的外包装可以是硬壳，例如硬塑料壳、铝壳、钢壳等。二次电池的外包装也可以是软包，例如袋式软包。软包的材质可以是塑料，作为塑料，可列举出聚丙烯、聚对苯二甲酸丁二醇酯以及聚丁二酸丁二醇酯等。In some embodiments, the outer packaging of the secondary battery may be a hard shell, such as a hard plastic shell, an aluminum shell, a steel shell, etc. The outer packaging of the secondary battery may also be a soft package, such as a bag-type soft package. The material of the soft package may be plastic, and examples of the plastic include polypropylene, polybutylene terephthalate, and polybutylene succinate.
[二次电池][Secondary battery]
本申请对二次电池的形状没有特别的限制，其可以是圆柱形、方形或其他任意的形状。例如，图2是作为一个示例的方形结构的二次电池5。所述二次电池也可以为钠离子电池、镁离子电池、钾离子电池。The present application has no particular restrictions on the shape of the secondary battery, which may be cylindrical, square or any other shape. For example, FIG2 is a secondary battery 5 of a square structure as an example. The secondary battery may also be a sodium ion battery, a magnesium ion battery, or a potassium ion battery.
在一些实施方式中，参照图3，外包装可包括壳体51和盖板53。其中，壳体51可包括底板和连接于底板上的侧板，底板和侧板围合形成容纳腔。壳体51具有与容纳腔连通的开口，盖板53能够盖设于所述开口，以封闭所述容纳腔。正极极片、负极极片和隔离膜可经卷绕工艺或叠片工艺形成电极组件52。电极组件52封装于所述容纳腔内。电解液浸润于电极组件52中。二次电池5所含电极组件52的数量可以为一个或多个，本领域技术人员可根据具体实际需求进行选择。In some embodiments, referring to FIG. 3 , the outer package may include a shell 51 and a cover plate 53. Among them, the shell 51 may include a bottom plate and a side plate connected to the bottom plate, and the bottom plate and the side plate enclose a receiving cavity. The shell 51 has an opening connected to the receiving cavity, and the cover plate 53 can be covered on the opening to close the receiving cavity. The positive electrode sheet, the negative electrode sheet and the isolation film can form an electrode assembly 52 through a winding process or a lamination process. The electrode assembly 52 is encapsulated in the receiving cavity. The electrolyte is infiltrated in the electrode assembly 52. The number of electrode assemblies 52 contained in the secondary battery 5 can be one or more, and those skilled in the art can select according to specific actual needs.
[电池模块][Battery module]
在一些实施方式中，二次电池可以组装成电池模块，电池模块所含二次电池的数量可以为一个或多个，具体数量本领域技术人员可根据电池模块的应用和容量进行选择。In some embodiments, secondary batteries may be assembled into a battery module. The number of secondary batteries contained in the battery module may be one or more, and the specific number may be selected by those skilled in the art according to the application and capacity of the battery module.
图4是作为一个示例的电池模块4。参照图4，在电池模块4中，多个二次电池5可以是沿电池模块4的长度方向依次排列设置。当然，也可以按照其他任意的方式进行排布。进一步可以通过紧固件将该多个二次电池5进行固定。FIG4 is a battery module 4 as an example. Referring to FIG4 , in the battery module 4, a plurality of secondary batteries 5 may be arranged in sequence along the length direction of the battery module 4. Of course, they may also be arranged in any other manner. Further, the plurality of secondary batteries 5 may be fixed by fasteners.
可选地，电池模块4还可以包括具有容纳空间的外壳，多个二次电池5容纳于该容纳空间。Optionally, the battery module 4 may further include a housing having a housing space, and the plurality of secondary batteries 5 are housed in the housing space.
[电池包][Battery Pack]
在一些实施方式中，上述电池模块还可以组装成电池包，电池包 所含电池模块的数量可以为一个或多个，具体数量本领域技术人员可根据电池包的应用和容量进行选择。In some embodiments, the battery modules can also be assembled into a battery pack. The number of battery modules included may be one or more, and the specific number can be selected by those skilled in the art according to the application and capacity of the battery pack.
图5和图6是作为一个示例的电池包1。参照图5和图6，在电池包1中可以包括电池箱和设置于电池箱中的多个电池模块4。电池箱包括上箱体2和下箱体3，上箱体2能够盖设于下箱体3，并形成用于容纳电池模块4的封闭空间。多个电池模块4可以按照任意的方式排布于电池箱中。FIG5 and FIG6 are battery packs 1 as an example. Referring to FIG5 and FIG6 , the battery pack 1 may include a battery box and a plurality of battery modules 4 disposed in the battery box. The battery box includes an upper box body 2 and a lower box body 3, and the upper box body 2 can be covered on the lower box body 3 to form a closed space for accommodating the battery modules 4. The plurality of battery modules 4 can be arranged in the battery box in any manner.
[用电装置][Electrical devices]
本申请的一个实施方式中，提供一种用电装置，包括任意实施方式的二次电池、任意实施方式的电池模块或任意实施方式的电池包中的至少一种。In one embodiment of the present application, there is provided an electric device, comprising at least one of a secondary battery of any embodiment, a battery module of any embodiment, or a battery pack of any embodiment.
所述用电装置包括本申请提供的二次电池、电池模块、或电池包中的至少一种。所述二次电池、电池模块、或电池包可以用作所述用电装置的电源，也可以用作所述用电装置的能量存储单元。所述用电装置可以包括移动设备(例如手机、笔记本电脑等)、电动车辆(例如纯电动车、混合动力电动车、插电式混合动力电动车、电动自行车、电动踏板车、电动高尔夫球车、电动卡车等)、电气列车、船舶及卫星、储能***等，但不限于此。The electrical device includes at least one of the secondary battery, battery module, or battery pack provided in the present application. The secondary battery, battery module, or battery pack can be used as a power source for the electrical device, and can also be used as an energy storage unit for the electrical device. The electrical device may include mobile devices (such as mobile phones, laptops, etc.), electric vehicles (such as pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc., but are not limited thereto.
作为所述用电装置，可以根据其使用需求来选择二次电池、电池模块或电池包。As the electrical device, a secondary battery, a battery module or a battery pack may be selected according to its usage requirements.
图7是作为一个示例的用电装置。该用电装置为纯电动车、混合动力电动车、或插电式混合动力电动车等。为了满足该用电装置对二次电池的高功率和高能量密度的需求，可以采用电池包或电池模块。FIG7 is an example of an electric device. The electric device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle. In order to meet the electric device's requirements for high power and high energy density of secondary batteries, a battery pack or a battery module may be used.
作为另一个示例的装置可以是手机、平板电脑、笔记本电脑等。该装置通常要求轻薄化，可以采用二次电池作为电源。Another example of a device may be a mobile phone, a tablet computer, a notebook computer, etc. Such a device is usually required to be thin and light, and a secondary battery may be used as a power source.
实施例Example
以下，说明本申请的实施例。下面描述的实施例是示例性的，仅用于解释本申请，而不能理解为对本申请的限制。实施例中未注明具 体技术或条件的，按照本领域内的文献所描述的技术或条件或者按照产品说明书进行。所用试剂或仪器未注明生产厂商者，均为可以通过市购获得的常规产品。The following are examples of the present application. The examples described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. If specific techniques or conditions are required, they shall be carried out in accordance with the techniques or conditions described in the literature in this field or in accordance with the product instructions. Reagents or instruments used without indicating the manufacturer are all conventional products that can be purchased commercially.
一、制备方法1. Preparation method
实施例1Example 1
1)粘结剂的制备1) Preparation of binder
制备B-嵌段：利用炔基化合物作为链转移剂，聚合反应制备炔基封端的聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)；Preparation of B-block: using an alkynyl compound as a chain transfer agent to prepare alkynyl-terminated poly(acrylic acid-acrylamide-ethyl methacrylate) by polymerization reaction;
以8:1:1的摩尔比分别称取丙烯酸、甲基丙烯酸乙酯以及丙烯酰胺，量取500ml四氢呋喃，加入四口烧瓶，通入大量氮气，并逐渐加大搅拌速度，至1200转/分钟，加入单体质量1％的RAFT链转移剂(CTA-炔烃)和单体质量0.1％的偶氮二异丁腈，升温至75℃。反应6小时后，通过在液氮中冷却终止反应，溶液在过量的甲醇中沉淀。通过过滤收集聚合物，并用甲醇从氯仿中再沉淀两次。将所得产物在室温下真空干燥过夜以除去所有痕量的残留溶剂，得到重均分子量为40万的炔基封单端的聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)，即B-嵌段聚合物。Acrylic acid, ethyl methacrylate and acrylamide were weighed in a molar ratio of 8:1:1, 500 ml of tetrahydrofuran was measured, added to a four-necked flask, a large amount of nitrogen was introduced, and the stirring speed was gradually increased to 1200 rpm, 1% of the monomer mass of RAFT chain transfer agent (CTA-alkyne) and 0.1% of the monomer mass of azobisisobutyronitrile were added, and the temperature was raised to 75°C. After 6 hours of reaction, the reaction was terminated by cooling in liquid nitrogen, and the solution was precipitated in excess methanol. The polymer was collected by filtration and reprecipitated twice from chloroform with methanol. The resulting product was vacuum dried overnight at room temperature to remove all traces of residual solvents to obtain a poly (acrylic acid-acrylamide-ethyl methacrylate) with an alkynyl-capped single end having a weight average molecular weight of 400,000, i.e., a B-block polymer.
制备A-嵌段：利用叠氮化物作为引发剂，聚合反应制备叠氮化物封端的聚偏二氟乙烯；Preparation of A-block: using azide as an initiator, preparing azide-terminated polyvinylidene fluoride by polymerization reaction;
将单体质量1％的4-(氯甲基)过氧化苯甲酰溶解在300ml无水乙腈中，然后将溶液引入高压反应器中并用氮气(N2)吹扫30分钟。随后在室温下将4g的偏二氟乙烯单体转移到反应器中。将反应器内部的温度提高到90℃，并将反应混合物以500转/分钟的速度再搅拌3小时。将反应器用水冷却至室温并减压以除去未反应的单体。真空除去溶剂，所得固体用氯仿洗涤多次以除去引发剂残留物。最后将聚合物在45℃真空干燥，得到白色产物。将3mmol氯封端的聚偏氟乙烯和60mmol叠氮化钠(NaN3)溶解在600ml的N,N-二甲基甲酰胺(DMF)中并在60℃下搅拌过夜。将聚合物溶液浓缩并在混合溶剂 (甲醇与水的体积比为1:1)中沉淀三次。随后在45℃下真空干燥淡黄色产物，得到重均分子量为45万的叠氮化物封双端的聚偏二氟乙烯，即A-嵌段聚合物。1% of the monomer mass of 4-(chloromethyl)benzoyl peroxide was dissolved in 300 ml of anhydrous acetonitrile, and then the solution was introduced into a high-pressure reactor and purged with nitrogen (N 2 ) for 30 minutes. Subsequently, 4 g of vinylidene fluoride monomer was transferred to the reactor at room temperature. The temperature inside the reactor was raised to 90°C, and the reaction mixture was stirred at 500 rpm for another 3 hours. The reactor was cooled to room temperature with water and decompressed to remove unreacted monomers. The solvent was removed in vacuo, and the resulting solid was washed with chloroform several times to remove the initiator residues. Finally, the polymer was vacuum dried at 45°C to obtain a white product. 3 mmol of chlorine-terminated polyvinylidene fluoride and 60 mmol of sodium azide (NaN 3 ) were dissolved in 600 ml of N,N-dimethylformamide (DMF) and stirred at 60°C overnight. The polymer solution was concentrated and heated in a mixed solvent. The product was then vacuum dried at 45°C to obtain a polyvinylidene fluoride (PVDF) capped at both ends with azide and having a weight average molecular weight of 450,000, i.e., A-block polymer.
制备BAB型嵌段共聚物：Preparation of BAB type block copolymers:
将叠氮化物封双端的聚偏二氟乙烯、炔基封单端的聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)和溴化亚铜按照摩尔比1:2.5:4，添加到干燥的Schlenk管中，脱气处理后加入4ml无水N,N-二甲基甲酰胺(DMF)和0.14mmolN,N,N',N,'N”-五甲基二亚乙基三胺(PMDETA)。在60℃下搅拌反应3天，通过暴露于空气中终止反应。反应混合物通过中性氧化铝柱过滤除去铜催化剂，溶液减压浓缩并使用20倍过量的混合溶剂(甲醇与水的体积比为1:1)中进行沉淀，过滤收集产物，真空干燥得到重均分子量为120万的聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)-聚偏二氟乙烯-聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)三嵌段共聚物，其作为电池粘结剂使用。Polyvinylidene fluoride blocked at both ends by azide, poly(acrylic acid-acrylamide-ethyl methacrylate) blocked at one end by alkyne, and cuprous bromide were added to a dry Schlenk tube in a molar ratio of 1:2.5:4. After degassing, 4 ml of anhydrous N,N-dimethylformamide (DMF) and 0.14 mmol N,N,N',N,'N"-pentamethyldiethylenetriamine (PMDETA) were added. The reaction was stirred at 60°C for 3 days and terminated by exposure to air. The reaction mixture was filtered through a neutral alumina column to remove the copper catalyst, the solution was concentrated under reduced pressure and precipitated in a 20-fold excess of a mixed solvent (methanol to water volume ratio of 1:1), the product was collected by filtration, and vacuum dried to obtain a triblock copolymer of poly(acrylic acid-acrylamide-ethyl methacrylate)-polyvinylidene fluoride-poly(acrylic acid-acrylamide-ethyl methacrylate) with a weight average molecular weight of 1.2 million, which was used as a battery binder.
2)正极极片的制备2) Preparation of positive electrode
将锂镍钴锰(LiNi0.8Mn0.1Co0.1O2)材料、导电剂碳黑、实施例1制备的粘结剂、N-甲基吡咯烷酮(NMP)按重量比为96.9：2.1：1：21搅拌混合均匀，得到正极浆料，浆料的固含量为73％；之后将正极浆料均匀涂覆于正极集流体上，之后经过烘干、冷压、分切，得到正极极片。Lithium nickel cobalt manganese (LiNi 0.8 Mn 0.1 Co 0.1 O 2 ) material, conductive agent carbon black, the binder prepared in Example 1, and N-methylpyrrolidone (NMP) were stirred and mixed in a weight ratio of 96.9:2.1:1:21 to obtain a positive electrode slurry with a solid content of 73%. The positive electrode slurry was then evenly coated on a positive electrode current collector, and then dried, cold pressed, and cut to obtain a positive electrode sheet.
3)负极极片的制备3) Preparation of negative electrode sheet
将活性物质人造石墨、导电剂碳黑、粘结剂丁苯橡胶(SBR)、增稠剂羟甲基纤维素钠(CMC)按照重量比为96.2：0.8：0.8：1.2溶于溶剂去离子水中，混合均匀后制备成负极浆料；将负极浆料一次或多次均匀涂覆在负极集流体铜箔上，经过烘干、冷压、分切得到负极极片。The active material artificial graphite, the conductive agent carbon black, the binder styrene-butadiene rubber (SBR), and the thickener sodium hydroxymethyl cellulose (CMC) are dissolved in the solvent deionized water in a weight ratio of 96.2:0.8:0.8:1.2, and the negative electrode slurry is prepared after being evenly mixed; the negative electrode slurry is evenly coated on the negative electrode collector copper foil once or multiple times, and the negative electrode sheet is obtained after drying, cold pressing, and slitting.
4)隔离膜4) Isolation film
以聚丙烯膜作为隔离膜。 Polypropylene film is used as the isolation film.
5)电解液的制备5) Preparation of electrolyte
在氩气气氛手套箱中(H2O<0.1ppm，O2<0.1ppm)，将有机溶剂碳酸乙烯酯(EC)/碳酸甲乙酯(EMC)按照体积比3/7混合均匀，加入12.5％LiPF6锂盐溶解于有机溶剂中，搅拌均匀，得到实施例1的电解液。In an argon atmosphere glove box (H 2 O<0.1ppm, O 2 <0.1ppm), organic solvents ethylene carbonate (EC)/ethyl methyl carbonate (EMC) were mixed uniformly in a volume ratio of 3/7, 12.5% LiPF 6 lithium salt was added and dissolved in the organic solvent, and stirred uniformly to obtain the electrolyte of Example 1.
6)电池的制备6) Preparation of batteries
将实施例1正极极片、隔离膜、负极极片按顺序叠好，使隔离膜处于正、负极片之间起到隔离的作用，然后卷绕得到裸电芯，给裸电芯焊接极耳，并将裸电芯装入铝壳中，并在80℃下烘烤除水，随即注入电解液并封口，得到不带电的电池。不带电的电池再依次经过静置、热冷压、化成、整形、容量测试等工序，获得实施例1的锂离子电池产品。The positive electrode sheet, the separator, and the negative electrode sheet of Example 1 are stacked in order, so that the separator is between the positive and negative electrode sheets to play an isolating role, and then wound to obtain a bare cell, and the bare cell is welded with a pole ear, and the bare cell is placed in an aluminum shell, and baked at 80°C to remove water, and then the electrolyte is injected and sealed to obtain an uncharged battery. The uncharged battery is then subjected to the processes of static, hot and cold pressing, formation, shaping, and capacity testing in sequence to obtain the lithium-ion battery product of Example 1.
实施例2-11Example 2-11
实施例2-11的电池与实施例1的电池制备方法相似，但是通过分别调整A-嵌段以及B-嵌段的聚合反应温度和反应温度，调整A-嵌段以及B-嵌段的聚合度，调整A-嵌段以及B-嵌段的重均分子量，进而调整了聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)-聚偏二氟乙烯-聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)三嵌段共聚物的重均分子量，具体参数如表1和表3所示。The battery of Example 2-11 is similar to the battery preparation method of Example 1, but the weight average molecular weight of the poly(acrylic acid-acrylamide-ethyl methacrylate)-polyvinylidene fluoride-poly(acrylic acid-acrylamide-ethyl methacrylate) triblock copolymer is adjusted by adjusting the polymerization reaction temperature and reaction temperature of the A-block and the B-block, respectively, adjusting the polymerization degree of the A-block and the B-block, and adjusting the weight average molecular weight of the A-block and the B-block. The specific parameters are shown in Tables 1 and 3.
表1实施例2-11的聚合反应温度和时间参数
Table 1 Polymerization reaction temperature and time parameters of Examples 2-11
实施例12-15Examples 12-15
实施例12-15的电池与实施例1的电池制备方法相似，但是将粘结剂的质量分数分别调整为0.1％(实施例12)、0.2％(实施例13)、1.2％(实施例14)、3％(实施例15)，以正极活性物质的质量计，其余参数均与实施例1相同，具体参数如表3所示。The preparation methods of the batteries of Examples 12-15 are similar to those of Example 1, but the mass fractions of the binder are adjusted to 0.1% (Example 12), 0.2% (Example 13), 1.2% (Example 14), and 3% (Example 15), respectively, based on the mass of the positive electrode active material. The remaining parameters are the same as those of Example 1, and the specific parameters are shown in Table 3.
实施例16Example 16
实施例16的电池与实施例5的电池制备方法相似，但将A-嵌段替换成聚氟乙烯嵌段，具体参数如表3所示，制备方法如下：The preparation method of the battery of Example 16 is similar to that of the battery of Example 5, except that the A-block is replaced with a polyvinyl fluoride block. The specific parameters are shown in Table 3. The preparation method is as follows:
A-嵌段：将单体质量1％的4-(氯甲基)过氧化苯甲酰溶于300ml无水乙腈中，引入高压反应器中并用N2吹扫30分钟。在室温下将3.8g的氟乙烯转移到反应器中。将反应器内部的温度提高到90℃，反应混合物以500转/分钟的速度搅拌反应4.7小时。反应结束后除去溶剂，所得固体用氯仿多次洗涤以除去引发剂残留物，45℃真空干燥，得到白色产物，即氯封端的聚氟乙烯。将3mmol氯封端的聚氟乙烯和60mmolNaN3溶解在600mlDMF中并在60℃下搅拌过夜，聚合物溶液浓缩并在混合溶剂(甲醇与水的体积比为1:1)中沉淀三次。随后在45℃下真空干燥得到叠氮化物封双端的聚氟乙烯，即A-嵌段聚 合物。A-block: 1% of the monomer mass of 4-(chloromethyl)benzoyl peroxide was dissolved in 300ml of anhydrous acetonitrile, introduced into a high-pressure reactor and purged with N2 for 30 minutes. 3.8g of vinyl fluoride was transferred to the reactor at room temperature. The temperature inside the reactor was raised to 90°C, and the reaction mixture was stirred at 500 rpm for 4.7 hours. After the reaction was completed, the solvent was removed, and the resulting solid was washed with chloroform several times to remove the initiator residues, and vacuum dried at 45°C to obtain a white product, namely chlorine-terminated polyvinyl fluoride. 3mmol of chlorine-terminated polyvinyl fluoride and 60mmol of NaN3 were dissolved in 600ml of DMF and stirred at 60°C overnight. The polymer solution was concentrated and precipitated three times in a mixed solvent (the volume ratio of methanol to water was 1:1). Subsequently, it was vacuum dried at 45°C to obtain azide-terminated polyvinyl fluoride, namely A-block polyvinyl fluoride. Compound.
实施例17Embodiment 17
实施例17的电池与实施例5的电池制备方法相似，但是将A-嵌段替换成聚四氟乙烯嵌段，具体参数如表3所示，制备方法如下：The preparation method of the battery of Example 17 is similar to that of the battery of Example 5, but the A-block is replaced by a polytetrafluoroethylene block. The specific parameters are shown in Table 3. The preparation method is as follows:
A-嵌段：将单体质量1％的4-(氯甲基)过氧化苯甲酰溶于300ml无水乙腈，引入高压反应器中并用N2吹扫30分钟。室温下将4.2g的四氟乙烯转移到反应器中，反应器内部温度提高到90℃，将反应混合物以500转/分钟的速度搅拌4.7小时。反应结束后除去溶剂，所得固体用氯仿洗涤多次以除去引发剂残留物，45℃真空干燥，得到白色产物，即氯封端的聚四氟乙烯。将3mmol氯封端的聚四氟乙烯和60mmolNaN3溶解在600mlDMF中并在60℃下搅拌过夜。将聚合物溶液浓缩并在混合溶剂(甲醇与水的体积比为1:1)中沉淀三次，45℃下真空干燥得到叠氮化物封双端的聚四氟乙烯，即A-嵌段聚合物。A-block: 1% of the monomer mass of 4-(chloromethyl)benzoyl peroxide was dissolved in 300ml of anhydrous acetonitrile, introduced into a high-pressure reactor and purged with N2 for 30 minutes. 4.2g of tetrafluoroethylene was transferred to the reactor at room temperature, the internal temperature of the reactor was raised to 90°C, and the reaction mixture was stirred at 500 rpm for 4.7 hours. After the reaction was completed, the solvent was removed, and the obtained solid was washed with chloroform several times to remove the initiator residues, and vacuum dried at 45°C to obtain a white product, namely chlorine-terminated polytetrafluoroethylene. 3mmol of chlorine-terminated polytetrafluoroethylene and 60mmol of NaN3 were dissolved in 600ml of DMF and stirred at 60°C overnight. The polymer solution was concentrated and precipitated three times in a mixed solvent (the volume ratio of methanol to water was 1:1), and vacuum dried at 45°C to obtain azide-terminated polytetrafluoroethylene, namely A-block polymer.
实施例18Embodiment 18
实施例18的电池与实施例5的电池制备方法相似，但是将B-嵌段替换成聚(丙烯酸-丙烯腈-甲基丙烯酸乙酯)，具体参数如表3所示，制备方法如下：The preparation method of the battery of Example 18 is similar to that of the battery of Example 5, but the B-block is replaced with poly(acrylic acid-acrylonitrile-ethyl methacrylate). The specific parameters are shown in Table 3. The preparation method is as follows:
B-嵌段：以8:1:1的摩尔比分别称取丙烯酸、甲基丙烯酸乙酯以及丙烯腈，量取500ml四氢呋喃，加入四口烧瓶，通入大量氮气，并逐渐加大搅拌速度，至1200转/分钟，加入单体质量1％的RAFT链转移剂(CTA-炔烃)和单体质量0.1％的偶氮二异丁腈，升温至75℃。反应5小时后，通过在液氮中冷却终止反应，溶液在过量的甲醇中沉淀。通过过滤收集聚合物，并用甲醇从氯仿中再沉淀两次。将所得产物在室温下真空干燥过夜以除去所有痕量的残留溶剂，得到重均分子量为25万的炔基封单端的聚(丙烯酸-丙烯腈-甲基丙烯酸乙酯)，即B-嵌段聚合物。B-block: Acrylic acid, ethyl methacrylate and acrylonitrile were weighed in a molar ratio of 8:1:1, 500 ml of tetrahydrofuran was measured, added to a four-necked flask, a large amount of nitrogen was introduced, and the stirring speed was gradually increased to 1200 rpm, 1% of the monomer mass of RAFT chain transfer agent (CTA-alkyne) and 0.1% of the monomer mass of azobisisobutyronitrile were added, and the temperature was raised to 75°C. After 5 hours of reaction, the reaction was terminated by cooling in liquid nitrogen, and the solution was precipitated in excess methanol. The polymer was collected by filtration and reprecipitated twice from chloroform with methanol. The resulting product was vacuum dried overnight at room temperature to remove all traces of residual solvents to obtain a single-end poly (acrylic acid-acrylonitrile-ethyl methacrylate) with an alkynyl-capped weight average molecular weight of 250,000, i.e., a B-block polymer.
实施例19Embodiment 19
实施例19的电池与实施例5的电池制备方法相似，但是将B-嵌 段替换成聚(丙烯酸-甲基丙烯酸乙酯)，具体参数如表3所示，制备方法如下：The battery of Example 19 is prepared in a similar manner to the battery of Example 5, except that the B- The segment is replaced with poly(acrylic acid-ethyl methacrylate), the specific parameters are shown in Table 3, and the preparation method is as follows:
B-嵌段：以8:1的摩尔比分别称取丙烯酸以及甲基丙烯酸乙酯，量取500ml四氢呋喃，加入四口烧瓶，通入大量氮气，并逐渐加大搅拌速度，至1200转/分钟，加入单体质量1％的RAFT链转移剂(CTA-炔烃)和单体质量0.1％的偶氮二异丁腈，升温至60℃。反应7小时后，通过在液氮中冷却终止反应，溶液在过量的甲醇中沉淀。通过过滤收集聚合物，并用甲醇从氯仿中再沉淀两次。将所得产物在室温下真空干燥过夜以除去所有痕量的残留溶剂，得到重均分子量为25万的炔基封单端的聚(丙烯酸-甲基丙烯酸乙酯)，即B-嵌段聚合物。B-block: Weigh acrylic acid and ethyl methacrylate in a molar ratio of 8:1, measure 500 ml of tetrahydrofuran, add to a four-necked flask, pass a large amount of nitrogen, and gradually increase the stirring speed to 1200 rpm, add 1% of the monomer mass of RAFT chain transfer agent (CTA-alkyne) and 0.1% of the monomer mass of azobisisobutyronitrile, and heat to 60°C. After 7 hours of reaction, the reaction was terminated by cooling in liquid nitrogen, and the solution was precipitated in excess methanol. The polymer was collected by filtration and reprecipitated twice from chloroform with methanol. The resulting product was vacuum dried overnight at room temperature to remove all traces of residual solvent to obtain a single-end poly (acrylic acid-ethyl methacrylate) with an alkynyl-capped weight average molecular weight of 250,000, i.e., a B-block polymer.
实施例20Embodiment 20
实施例20的电池与实施例5的电池制备方法相似，但是将B-嵌段替换成聚丙烯酸，具体参数如表3所示，制备方法如下：The preparation method of the battery of Example 20 is similar to that of the battery of Example 5, but the B-block is replaced with polyacrylic acid. The specific parameters are shown in Table 3. The preparation method is as follows:
B-嵌段：称取丙烯酸，量取500ml四氢呋喃，加入四口烧瓶，通入大量氮气，并逐渐加大搅拌速度，至1200转/分钟，加入单体质量1％的RAFT链转移剂(CTA-炔烃)和单体质量0.1％的偶氮二异丁腈，升温至60℃。反应7小时后，通过在液氮中冷却终止反应，溶液在过量的甲醇中沉淀。通过过滤收集聚合物，并用甲醇从氯仿中再沉淀两次。将所得产物在室温下真空干燥过夜以除去所有痕量的残留溶剂，得到重均分子量为25万的炔基封单端的聚丙烯酸，即B-嵌段聚合物。B-block: Weigh acrylic acid, measure 500 ml of tetrahydrofuran, add to a four-necked flask, pass a large amount of nitrogen, and gradually increase the stirring speed to 1200 rpm, add 1% of the monomer mass of RAFT chain transfer agent (CTA-alkyne) and 0.1% of the monomer mass of azobisisobutyronitrile, and heat to 60°C. After reacting for 7 hours, the reaction is terminated by cooling in liquid nitrogen, and the solution is precipitated in excess methanol. The polymer is collected by filtration and reprecipitated twice from chloroform with methanol. The resulting product is vacuum dried overnight at room temperature to remove all traces of residual solvents to obtain a single-end polyacrylic acid with an alkynyl capping having a weight average molecular weight of 250,000, i.e., a B-block polymer.
实施例21Embodiment 21
实施例21的电池与实施例5的电池制备方法相似，但是将B-嵌段替换成聚(丙烯酸-丙烯腈)，具体参数如表3所示，制备方法如下：The preparation method of the battery of Example 21 is similar to that of the battery of Example 5, but the B-block is replaced with poly(acrylic acid-acrylonitrile). The specific parameters are shown in Table 3. The preparation method is as follows:
B-嵌段：以8:1的摩尔比分别称取丙烯酸、丙烯腈，量取500ml四氢呋喃，加入四口烧瓶，通入大量氮气，并逐渐加大搅拌速度，至1200转/分钟，加入单体质量1％的RAFT链转移剂(CTA-炔烃)和单体质量0.1％的偶氮二异丁腈，升温至60℃。反应7小时后，通过 在液氮中冷却终止反应，溶液在过量的甲醇中沉淀。通过过滤收集聚合物，并用甲醇从氯仿中再沉淀两次。将所得产物在室温下真空干燥过夜以除去所有痕量的残留溶剂，得到重均分子量为25万的炔基封单端的聚(丙烯酸-丙烯腈)，即B-嵌段聚合物。B-block: Weigh acrylic acid and acrylonitrile at a molar ratio of 8:1, measure 500 ml of tetrahydrofuran, add them into a four-necked flask, introduce a large amount of nitrogen, gradually increase the stirring speed to 1200 rpm, add 1% of the monomer weight of RAFT chain transfer agent (CTA-alkyne) and 0.1% of the monomer weight of azobisisobutyronitrile, and heat to 60°C. After reacting for 7 hours, The reaction was terminated by cooling in liquid nitrogen, and the solution was precipitated in excess methanol. The polymer was collected by filtration and reprecipitated twice from chloroform with methanol. The resulting product was vacuum dried overnight at room temperature to remove all traces of residual solvent to obtain an alkynyl-capped single-end poly(acrylic acid-acrylonitrile) with a weight average molecular weight of 250,000, i.e., a B-block polymer.
实施例22Embodiment 22
实施例22的电池与实施例5的电池制备方法相似，但是将B-嵌段替换成聚(丙烯酸-丙烯酰胺)，具体参数如表3所示，制备方法如下：The preparation method of the battery of Example 22 is similar to that of the battery of Example 5, but the B-block is replaced with poly(acrylic acid-acrylamide). The specific parameters are shown in Table 3. The preparation method is as follows:
B-嵌段：以8:1的摩尔比分别称取丙烯酸、丙烯酰胺，量取500ml四氢呋喃，加入四口烧瓶，通入大量氮气，并逐渐加大搅拌速度，至1200转/分钟，加入单体质量1％的RAFT链转移剂(CTA-炔烃)和单体质量0.1％的偶氮二异丁腈，升温至60℃。反应7小时后，通过在液氮中冷却终止反应，溶液在过量的甲醇中沉淀。通过过滤收集聚合物，并用甲醇从氯仿中再沉淀两次。将所得产物在室温下真空干燥过夜以除去所有痕量的残留溶剂，得到重均分子量为25万的炔基封单端的聚(丙烯酸-丙烯酰胺)，即B-嵌段聚合物。B-block: Weigh acrylic acid and acrylamide at a molar ratio of 8:1, measure 500 ml of tetrahydrofuran, add to a four-necked flask, pass a large amount of nitrogen, and gradually increase the stirring speed to 1200 rpm, add 1% of the monomer mass of RAFT chain transfer agent (CTA-alkyne) and 0.1% of the monomer mass of azobisisobutyronitrile, and heat to 60°C. After 7 hours of reaction, the reaction is terminated by cooling in liquid nitrogen, and the solution is precipitated in excess methanol. The polymer is collected by filtration and reprecipitated twice from chloroform with methanol. The resulting product is vacuum dried overnight at room temperature to remove all traces of residual solvent to obtain a poly (acrylic acid-acrylamide) with an alkynyl capping at one end with a weight average molecular weight of 250,000, i.e., a B-block polymer.
实施例23Embodiment 23
实施例23的电池与实施例5的电池制备方法相似，但是将B-嵌段替换成聚(丙烯酸-丙烯腈-丙烯酰胺)，具体参数如表3所示，制备方法如下：The preparation method of the battery of Example 23 is similar to that of the battery of Example 5, but the B-block is replaced with poly(acrylic acid-acrylonitrile-acrylamide), the specific parameters are shown in Table 3, and the preparation method is as follows:
B-嵌段：以8:1:1的摩尔比分别称取丙烯酸、丙烯腈、丙烯酰胺，量取500ml四氢呋喃，加入四口烧瓶，通入大量氮气，并逐渐加大搅拌速度，至1200转/分钟，加入单体质量1％的RAFT链转移剂(CTA-炔烃)和单体质量0.1％的偶氮二异丁腈，升温至75℃。反应5小时后，通过在液氮中冷却终止反应，溶液在过量的甲醇中沉淀。通过过滤收集聚合物，并用甲醇从氯仿中再沉淀两次。将所得产物在室温下真空干燥过夜以除去所有痕量的残留溶剂，得到重均分子量为25万的炔基封单端的聚(丙烯酸-丙烯腈-丙烯酰胺)，即B-嵌段聚合物。B-block: Weigh acrylic acid, acrylonitrile and acrylamide in a molar ratio of 8:1:1, measure 500 ml of tetrahydrofuran, add to a four-necked flask, pass a large amount of nitrogen, and gradually increase the stirring speed to 1200 rpm, add 1% of the monomer mass of RAFT chain transfer agent (CTA-alkyne) and 0.1% of the monomer mass of azobisisobutyronitrile, and heat to 75°C. After 5 hours of reaction, the reaction is terminated by cooling in liquid nitrogen, and the solution is precipitated in excess methanol. The polymer is collected by filtration and reprecipitated twice from chloroform with methanol. The resulting product is vacuum dried overnight at room temperature to remove all traces of residual solvent to obtain a poly (acrylic acid-acrylonitrile-acrylamide) with an alkynyl capping at one end with a weight average molecular weight of 250,000, i.e., a B-block polymer.
实施例24 Embodiment 24
实施例24的电池与实施例5的电池制备方法相似，但是将A-嵌段替换成聚(偏二氟乙烯-六氟丙烯)嵌段，具体参数如表3所示，制备方法如下：The preparation method of the battery of Example 24 is similar to that of the battery of Example 5, but the A-block is replaced with a poly(vinylidene fluoride-hexafluoropropylene) block. The specific parameters are shown in Table 3. The preparation method is as follows:
A-嵌段：将单体质量1％的4-(氯甲基)过氧化苯甲酰溶于300ml无水乙腈，引入高压反应器中并用N2吹扫30分钟。室温下将15g的偏二氟乙烯和5g的六氟丙烯转移到反应器中，反应器内部温度提高到90℃，将反应混合物以500转/分钟的速度搅拌4.7小时。反应结束后除去溶剂，所得固体用氯仿洗涤多次以除去引发剂残留物，45℃真空干燥，得到白色产物，即氯封端的聚(偏二氟乙烯-六氟丙烯)。将3mmol氯封端的聚(偏二氟乙烯-六氟丙烯)和60mmolNaN3溶解在600mlDMF中并在60℃下搅拌过夜。将聚合物溶液浓缩并在在混合溶剂(甲醇与水的体积比为1:1)中沉淀三次，45℃下真空干燥得到叠氮化物封双端的聚(偏二氟乙烯-六氟丙烯)，即A-嵌段聚合物。A-block: 1% of the monomer mass of 4-(chloromethyl)benzoyl peroxide was dissolved in 300ml of anhydrous acetonitrile, introduced into a high-pressure reactor and purged with N2 for 30 minutes. 15g of vinylidene fluoride and 5g of hexafluoropropylene were transferred to the reactor at room temperature, the internal temperature of the reactor was raised to 90°C, and the reaction mixture was stirred at 500 rpm for 4.7 hours. After the reaction was completed, the solvent was removed, and the obtained solid was washed with chloroform several times to remove the initiator residues, and vacuum dried at 45°C to obtain a white product, namely chlorine-terminated poly(vinylidene fluoride-hexafluoropropylene). 3mmol of chlorine-terminated poly(vinylidene fluoride-hexafluoropropylene) and 60mmol of NaN3 were dissolved in 600ml of DMF and stirred at 60°C overnight. The polymer solution was concentrated and precipitated three times in a mixed solvent (the volume ratio of methanol to water was 1:1), and vacuum dried at 45°C to obtain azide-terminated poly(vinylidene fluoride-hexafluoropropylene), namely A-block polymer.
实施例25Embodiment 25
制备B-嵌段：利用RAFT链转移剂(CTA-炔烃)作为链转移剂，聚合反应制备炔基封端的聚偏二氟乙烯；其中RAFT链转移剂的结构式如下所示
Preparation of B-block: Using RAFT chain transfer agent (CTA-alkyne) as chain transfer agent, polymerization reaction is used to prepare acetylene-terminated polyvinylidene fluoride; wherein the structural formula of RAFT chain transfer agent is as follows
称取4g偏二氟乙烯，量取500ml四氢呋喃，加入四口烧瓶，通入大量氮气，并逐渐加大搅拌速度，至1200rpm，加入单体质量1％的RAFT链转移剂(CTA-炔烃)和单体质量0.1％的偶氮二异丁腈，升温至75℃。反应6小时后，通过在液氮中冷却终止反应，溶液在大量过量的甲醇中沉淀。通过过滤收集聚合物并用甲醇从氯仿中再沉淀两次。将所得产物在室温下真空干燥过夜以除去所有痕量的残留溶剂，得到末端具有炔基的聚偏二氟乙烯，即B-嵌段聚合物。 Weigh 4g of vinylidene fluoride, measure 500ml of tetrahydrofuran, add a four-necked flask, pass a large amount of nitrogen, and gradually increase the stirring speed to 1200rpm, add 1% of the monomer mass RAFT chain transfer agent (CTA-alkyne) and 0.1% of the monomer mass azobisisobutyronitrile, and warm to 75°C. After 6 hours of reaction, the reaction is terminated by cooling in liquid nitrogen, and the solution is precipitated in a large amount of excess methanol. The polymer is collected by filtration and reprecipitated twice from chloroform with methanol. The product is vacuum dried overnight at room temperature to remove all traces of residual solvent to obtain polyvinylidene fluoride with alkynyl groups at the end, i.e., B-block polymer.
制备A-嵌段：利用叠氮化物作为引发剂，聚合反应制备叠氮化物封端的聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)；Preparation of A-block: using azide as an initiator, a polymerization reaction is performed to prepare azide-terminated poly(acrylic acid-acrylamide-ethyl methacrylate);
将单体质量1％的4-(氯甲基)过氧化苯甲酰溶解在300ml无水乙腈中，然后将溶液引入高压反应器中并用N2吹扫30分钟。随后在室温下，以8:1:1的摩尔比分别称取丙烯酸单体、丙烯酰胺单体以及甲基丙烯酸乙酯单体转移到反应器中。将反应器内部的温度提高到90℃，并将反应混合物以500rpm的速度再搅拌3小时。将反应器用水冷却至室温并减压以除去未反应的单体。真空除去溶剂，所得固体用氯仿洗涤多次以除去引发剂残留物。最后将聚合物在45℃真空干燥，得到白色产物。将3mmol氯封端的聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)和60mmol叠氮化钠(NaN3)溶解在600ml的N,N-二甲基甲酰胺(DMF)中并在60℃下搅拌过夜。将聚合物溶液浓缩并在混合溶剂(甲醇与水的体积比为1:1)中沉淀三次。随后在45℃下真空干燥淡黄色产物，得到两端均包含叠氮化物的聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)，即A-嵌段聚合物。1% of the monomer mass of 4-(chloromethyl)benzoyl peroxide was dissolved in 300 ml of anhydrous acetonitrile, and then the solution was introduced into a high-pressure reactor and purged with N 2 for 30 minutes. Subsequently, acrylic acid monomer, acrylamide monomer and ethyl methacrylate monomer were weighed and transferred to the reactor in a molar ratio of 8:1:1 at room temperature. The temperature inside the reactor was raised to 90°C, and the reaction mixture was stirred at 500 rpm for another 3 hours. The reactor was cooled to room temperature with water and decompressed to remove unreacted monomers. The solvent was removed in vacuo, and the obtained solid was washed with chloroform several times to remove the initiator residue. Finally, the polymer was dried in vacuo at 45°C to obtain a white product. 3 mmol of chlorine-terminated poly(acrylic acid-acrylamide-ethyl methacrylate) and 60 mmol of sodium azide (NaN 3 ) were dissolved in 600 ml of N,N-dimethylformamide (DMF) and stirred at 60°C overnight. The polymer solution was concentrated and precipitated three times in a mixed solvent (methanol to water volume ratio of 1:1). The pale yellow product was then dried in vacuo at 45° C. to obtain poly(acrylic acid-acrylamide-ethyl methacrylate) containing azides at both ends, ie, the A-block polymer.
制备BAB型嵌段共聚物：Preparation of BAB type block copolymers:
将两端均具有叠氮基团的聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)末端具有炔基的聚偏二氟乙烯和溴化亚铜按照摩尔比1:2.5:4，添加到干燥的Schlenk管中，脱气处理后加入4ml无水N,N-二甲基甲酰胺(DMF)和0.14mmolN,N,N',N,'N”-五甲基二亚乙基三胺(PMDETA)。在60℃下搅拌反应3天，通过暴露于空气中终止反应。反应混合物通过中性氧化铝柱过滤除去铜催化剂，将溶液减压浓缩并在20倍过量的混合溶剂(甲醇与水的体积比为1:1)中进行沉淀，过滤收集产物，真空干燥得到重均分子量为120万的聚偏二氟乙烯-聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)-聚偏二氟乙烯嵌段共聚物，其作为电池粘结剂使用。Poly(acrylic acid-acrylamide-ethyl methacrylate) having azide groups at both ends and polyvinylidene fluoride having alkynyl groups at the ends and cuprous bromide were added to a dry Schlenk tube in a molar ratio of 1:2.5:4. After degassing, 4 ml of anhydrous N,N-dimethylformamide (DMF) and 0.14 mmol N,N,N',N,'N"-pentamethyldiethylenetriamine (PMDETA) were added. The reaction was stirred at 60°C for 3 days and terminated by exposure to air. The reaction mixture was filtered through a neutral alumina column to remove the copper catalyst, the solution was concentrated under reduced pressure and precipitated in a 20-fold excess of a mixed solvent (the volume ratio of methanol to water was 1:1), the product was collected by filtration, and vacuum dried to obtain a polyvinylidene fluoride-poly(acrylic acid-acrylamide-ethyl methacrylate)-polyvinylidene fluoride block copolymer with a weight average molecular weight of 1.2 million, which was used as a battery binder.
实施例26-35Examples 26-35
实施例26-35的电池与实施例25的电池制备方法相似，但是通 过分别调整A-嵌段以及B-嵌段的聚合反应温度和反应温度，调整A-嵌段以及B-嵌段的聚合度，调整A-嵌段以及B-嵌段的重均分子量，进而调整了聚偏二氟乙烯-聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)-聚偏二氟乙烯的重均分子量，具体参数如表2所示。The batteries of Examples 26-35 are prepared in a similar manner to the battery of Example 25, but The weight average molecular weight of polyvinylidene fluoride-poly(acrylic acid-acrylamide-ethyl methacrylate)-polyvinylidene fluoride was adjusted by adjusting the polymerization reaction temperature and reaction temperature of the A-block and the B-block, adjusting the polymerization degree of the A-block and the B-block, and adjusting the weight average molecular weight of the A-block and the B-block. The specific parameters are shown in Table 2.
表2实施例26-35的聚合反应温度和时间参数
Table 2 Polymerization reaction temperature and time parameters of Examples 26-35
实施例36-39Examples 36-39
实施例36-39的电池与实施例25的电池制备方法相似，但是将粘结剂的质量分数分别调整为0.1％(实施例36)、0.2％(实施例37)、1.2％(实施例38)、3％(实施例39)，以正极活性物质的质量计，其余参数均与实施例25相同，具体参数如表1和表2所示。The preparation methods of the batteries of Examples 36-39 are similar to those of Example 25, but the mass fraction of the binder is adjusted to 0.1% (Example 36), 0.2% (Example 37), 1.2% (Example 38), and 3% (Example 39), respectively, based on the mass of the positive electrode active material. The remaining parameters are the same as those of Example 25, and the specific parameters are shown in Tables 1 and 2.
实施例40Embodiment 40
实施例40与实施例25的电池制备方法相似，但是将B-嵌段替换成聚氟乙烯嵌段，具体参数如表3所示，制备方法如下，The preparation method of the battery of Example 40 is similar to that of Example 25, but the B-block is replaced by a polyvinyl fluoride block. The specific parameters are shown in Table 3. The preparation method is as follows:
称取4g氟乙烯，量取500ml四氢呋喃，加入四口烧瓶，通入大 量氮气，并逐渐加大搅拌速度，至1200rpm，加入单体质量1％的RAFT链转移剂(CTA-炔烃)和单体质量0.1％的偶氮二异丁腈，升温至75℃。反应6小时后，通过在液氮中冷却终止反应，溶液在大量过量的甲醇中沉淀。通过过滤收集聚合物并用甲醇从氯仿中再沉淀两次。将所得产物在室温下真空干燥过夜以除去所有痕量的残留溶剂，得到末端具有炔基的聚氟乙烯，即B-嵌段聚合物。Weigh 4g of vinyl fluoride and 500ml of tetrahydrofuran into a four-necked flask and pass a large The mixture was stirred for 2 hours at 40 ° C. ...
实施例41Embodiment 41
实施例41与实施例25的电池制备方法相似，但是将B-嵌段替换成聚四氟乙烯嵌段，具体参数如表3所示，制备方法如下，The battery preparation method of Example 41 is similar to that of Example 25, but the B-block is replaced with a polytetrafluoroethylene block. The specific parameters are shown in Table 3. The preparation method is as follows:
称取4g四氟乙烯，量取500ml四氢呋喃，加入四口烧瓶，通入大量氮气，并逐渐加大搅拌速度，至1200rpm，加入单体质量1％的RAFT链转移剂(CTA-炔烃)和单体质量0.1％的偶氮二异丁腈，升温至75℃。反应6小时后，通过在液氮中冷却终止反应，溶液在大量过量的甲醇中沉淀。通过过滤收集聚合物并用甲醇从氯仿中再沉淀两次。将所得产物在室温下真空干燥过夜以除去所有痕量的残留溶剂，得到末端具有炔基的聚四氟乙烯，即B-嵌段聚合物。Weigh 4g tetrafluoroethylene, measure 500ml tetrahydrofuran, add to a four-necked flask, pass a large amount of nitrogen, and gradually increase the stirring speed to 1200rpm, add 1% of the monomer mass RAFT chain transfer agent (CTA-alkyne) and 0.1% of the monomer mass azobisisobutyronitrile, and warm to 75°C. After 6 hours of reaction, the reaction is terminated by cooling in liquid nitrogen, and the solution is precipitated in a large amount of excess methanol. The polymer is collected by filtration and reprecipitated twice from chloroform with methanol. The product therefrom is vacuum dried overnight at room temperature to remove all traces of residual solvent to obtain polytetrafluoroethylene with alkynyl groups at the end, i.e., B-block polymer.
实施例42Embodiment 42
实施例42与实施例25的电池制备方法相似，但是将B-嵌段替换成聚(偏二氟乙烯-六氟丙烯)嵌段，具体参数如表3所示，制备方法如下，The preparation method of the battery of Example 42 is similar to that of Example 25, but the B-block is replaced with a poly(vinylidene fluoride-hexafluoropropylene) block. The specific parameters are shown in Table 3. The preparation method is as follows:
称取15g的偏二氟乙烯和5g的六氟丙烯，量取500ml四氢呋喃，加入四口烧瓶，通入大量氮气，并逐渐加大搅拌速度，至1200rpm，加入单体质量1％的RAFT链转移剂(CTA-炔烃)和单体质量0.1％的偶氮二异丁腈，升温至75℃。反应6小时后，通过在液氮中冷却终止反应，溶液在大量过量的甲醇中沉淀。通过过滤收集聚合物并用甲醇从氯仿中再沉淀两次。将所得产物在室温下真空干燥过夜以除去所有痕量的残留溶剂，得到末端具有炔基的(偏二氟乙烯-六氟丙烯)，即B-嵌段聚合物。 Weigh 15g of vinylidene fluoride and 5g of hexafluoropropylene, measure 500ml of tetrahydrofuran, add a four-necked flask, pass a large amount of nitrogen, and gradually increase the stirring speed to 1200rpm, add 1% of the monomer mass RAFT chain transfer agent (CTA-alkyne) and 0.1% of the monomer mass azobisisobutyronitrile, and warm to 75°C. After 6 hours of reaction, the reaction is terminated by cooling in liquid nitrogen, and the solution is precipitated in a large amount of excess methanol. The polymer is collected by filtration and reprecipitated twice from chloroform with methanol. The product obtained is vacuum dried overnight at room temperature to remove all traces of residual solvent to obtain (vinylidene fluoride-hexafluoropropylene) with alkynyl groups at the end, i.e., B-block polymer.
实施例43Embodiment 43
实施例43与实施例26的电池制备方法相似，但是将A-嵌段替换成聚丙烯酸嵌段，具体参数如表3所示，制备方法如下，The battery preparation method of Example 43 is similar to that of Example 26, but the A-block is replaced with a polyacrylic acid block. The specific parameters are shown in Table 3. The preparation method is as follows:
将单体质量1％的4-(氯甲基)过氧化苯甲酰溶解在300ml无水乙腈中，然后将溶液引入高压反应器中并用N2吹扫30分钟。随后在室温下，称取一定量的丙烯酸单体转移到反应器中。将反应器内部的温度提高到90℃，并将反应混合物以500rpm的速度再搅拌3小时。将反应器用水冷却至室温并减压以除去未反应的单体。真空除去溶剂，所得固体用氯仿洗涤多次以除去引发剂残留物。最后将聚合物在45℃真空干燥，得到白色产物。将3mmol氯封端的聚丙烯酸和60mmol叠氮化钠(NaN3)溶解在600ml的N,N-二甲基甲酰胺(DMF)中并在60℃下搅拌过夜。将聚合物溶液浓缩并在混合溶剂(甲醇与水的体积比为1:1)中沉淀三次。随后在45℃下真空干燥淡黄色产物，得到两端均包含叠氮化物的聚丙烯酸嵌段，即A-嵌段聚合物。1% of the monomer mass of 4-(chloromethyl)benzoyl peroxide was dissolved in 300 ml of anhydrous acetonitrile, and then the solution was introduced into a high-pressure reactor and purged with N 2 for 30 minutes. Subsequently, at room temperature, a certain amount of acrylic acid monomer was weighed and transferred to the reactor. The temperature inside the reactor was raised to 90°C, and the reaction mixture was stirred at 500 rpm for another 3 hours. The reactor was cooled to room temperature with water and decompressed to remove unreacted monomers. The solvent was removed in vacuo, and the resulting solid was washed with chloroform several times to remove the initiator residues. Finally, the polymer was vacuum dried at 45°C to obtain a white product. 3 mmol of chlorine-terminated polyacrylic acid and 60 mmol of sodium azide (NaN 3 ) were dissolved in 600 ml of N,N-dimethylformamide (DMF) and stirred at 60°C overnight. The polymer solution was concentrated and precipitated three times in a mixed solvent (the volume ratio of methanol to water was 1:1). The pale yellow product was then vacuum dried at 45°C to obtain a polyacrylic acid block containing azides at both ends, i.e., A-block polymer.
实施例44Embodiment 44
实施例44与实施例26的电池制备方法相似，但是将A-嵌段替换成聚(丙烯酸-丙烯酰胺)嵌段，具体参数如表3所示，制备方法如下，The battery preparation method of Example 44 is similar to that of Example 26, but the A-block is replaced with a poly(acrylic acid-acrylamide) block. The specific parameters are shown in Table 3. The preparation method is as follows:
将单体质量1％的4-(氯甲基)过氧化苯甲酰溶解在300ml无水乙腈中，然后将溶液引入高压反应器中并用N2吹扫30分钟。随后在室温下，以8:1的摩尔比分别称取丙烯酸单体、丙烯酰胺转移到反应器中。将反应器内部的温度提高到90℃，并将反应混合物以500rpm的速度再搅拌3小时。将反应器用水冷却至室温并减压以除去未反应的单体。真空除去溶剂，所得固体用氯仿洗涤多次以除去引发剂残留物。最后将聚合物在45℃真空干燥，得到白色产物。将3mmol氯封端的聚(丙烯酸-丙烯酰胺)和60mmol叠氮化钠(NaN3)溶解在600ml的N,N-二甲基甲酰胺(DMF)中并在60℃下搅拌过夜。将聚合物溶液浓缩并在混合溶剂(甲醇与水的体积比为1:1)中沉淀三次。随后 在45℃下真空干燥淡黄色产物，得到两端均包含叠氮化物的聚(丙烯酸-丙烯酰胺)嵌段，即A-嵌段聚合物。1% of the monomer mass of 4-(chloromethyl)benzoyl peroxide was dissolved in 300 ml of anhydrous acetonitrile, and then the solution was introduced into a high-pressure reactor and purged with N2 for 30 minutes. Subsequently, at room temperature, acrylic acid monomer and acrylamide were weighed and transferred to the reactor in a molar ratio of 8:1. The temperature inside the reactor was raised to 90°C, and the reaction mixture was stirred at 500 rpm for another 3 hours. The reactor was cooled to room temperature with water and decompressed to remove unreacted monomers. The solvent was removed in vacuo, and the resulting solid was washed with chloroform several times to remove the initiator residues. Finally, the polymer was vacuum dried at 45°C to obtain a white product. 3 mmol of chlorine-terminated poly(acrylic acid-acrylamide) and 60 mmol of sodium azide ( NaN3 ) were dissolved in 600 ml of N,N-dimethylformamide (DMF) and stirred at 60°C overnight. The polymer solution was concentrated and precipitated three times in a mixed solvent (the volume ratio of methanol to water was 1:1). Subsequently The pale yellow product was dried in vacuo at 45°C to obtain a poly(acrylic acid-acrylamide) block containing azides at both ends, ie, an A-block polymer.
实施例45Embodiment 45
实施例45与实施例26的电池制备方法相似，但是将A-嵌段替换成聚(丙烯酸-丙烯腈-丙烯酰胺)嵌段，具体参数如表3所示，制备方法如下，The battery preparation method of Example 45 is similar to that of Example 26, but the A-block is replaced with a poly(acrylic acid-acrylonitrile-acrylamide) block. The specific parameters are shown in Table 3. The preparation method is as follows:
将单体质量1％的4-(氯甲基)过氧化苯甲酰溶解在300ml无水乙腈中，然后将溶液引入高压反应器中并用N2吹扫30分钟。随后在室温下，以8:1:1的摩尔比分别称取丙烯酸单体、丙烯腈单体以及丙烯酰胺单体转移到反应器中。将反应器内部的温度提高到90℃，并将反应混合物以500rpm的速度再搅拌3小时。将反应器用水冷却至室温并减压以除去未反应的单体。真空除去溶剂，所得固体用氯仿洗涤多次以除去引发剂残留物。最后将聚合物在45℃真空干燥，得到白色产物。将3mmol氯封端的聚(丙烯酸-丙烯腈-丙烯酰胺)和60mmol叠氮化钠(NaN3)溶解在600ml的N,N-二甲基甲酰胺(DMF)中并在60℃下搅拌过夜。将聚合物溶液浓缩并在混合溶剂(甲醇与水的体积比为1:1)中沉淀三次。随后在45℃下真空干燥淡黄色产物，得到两端均包含叠氮化物的聚(丙烯酸-丙烯腈-丙烯酰胺)嵌段，即A-嵌段聚合物。1% of the monomer mass of 4-(chloromethyl)benzoyl peroxide was dissolved in 300 ml of anhydrous acetonitrile, and then the solution was introduced into a high-pressure reactor and purged with N 2 for 30 minutes. Subsequently, acrylic acid monomer, acrylonitrile monomer and acrylamide monomer were weighed and transferred to the reactor in a molar ratio of 8:1:1 at room temperature. The temperature inside the reactor was raised to 90°C, and the reaction mixture was stirred at a speed of 500 rpm for another 3 hours. The reactor was cooled to room temperature with water and decompressed to remove unreacted monomers. The solvent was removed in vacuo, and the obtained solid was washed with chloroform several times to remove the initiator residue. Finally, the polymer was vacuum dried at 45°C to obtain a white product. 3 mmol of chlorine-terminated poly(acrylic acid-acrylonitrile-acrylamide) and 60 mmol of sodium azide (NaN 3 ) were dissolved in 600 ml of N,N-dimethylformamide (DMF) and stirred at 60°C overnight. The polymer solution was concentrated and precipitated three times in a mixed solvent (methanol to water volume ratio of 1:1). The pale yellow product was then dried in vacuo at 45° C. to obtain a poly(acrylic acid-acrylonitrile-acrylamide) block containing azides at both ends, namely, an A-block polymer.
对比例1Comparative Example 1
对比例1的电池与实施例1的电池制备方法相似，但是粘结剂为聚偏二氟乙烯，具体参数如表3所示，购买自索尔维集团的5130。The preparation method of the battery of Comparative Example 1 is similar to that of the battery of Example 1, but the binder is polyvinylidene fluoride, the specific parameters of which are shown in Table 3, and the binder is 5130 purchased from Solvay Group.
对比例2Comparative Example 2
对比例2的电池与实施例1的电池制备方法相似，但是粘结剂为聚丙烯酸，具体参数如表3所示，制备方法如下：The preparation method of the battery of Comparative Example 2 is similar to that of the battery of Example 1, but the binder is polyacrylic acid. The specific parameters are shown in Table 3. The preparation method is as follows:
称取丙烯酸，量取500ml四氢呋喃，加入四口烧瓶，通入大量氮气，并逐渐加大搅拌速度，至1200转/分钟，加入单体质量1％的RAFT链转移剂(CTA-炔烃)和单体质量0.1％的偶氮二异丁腈，升温至60℃。 反应7小时后，通过在液氮中冷却终止反应，溶液在过量的甲醇中沉淀。通过过滤收集聚合物，并用甲醇从氯仿中再沉淀两次。将所得聚合物在室温下真空干燥过夜以除去所有痕量的残留溶剂，得到目标粘结剂。Weigh acrylic acid and 500 ml of tetrahydrofuran, add them into a four-necked flask, introduce a large amount of nitrogen, and gradually increase the stirring speed to 1200 rpm. Add 1% of the monomer weight of RAFT chain transfer agent (CTA-alkyne) and 0.1% of the monomer weight of azobisisobutyronitrile, and raise the temperature to 60°C. After 7 hours of reaction, the reaction was terminated by cooling in liquid nitrogen and the solution was precipitated in excess methanol. The polymer was collected by filtration and reprecipitated twice from chloroform with methanol. The resulting polymer was dried overnight in vacuum at room temperature to remove all traces of residual solvent to obtain the target binder.
对比例3Comparative Example 3
对比例3的电池与实施例1的电池制备方法相似，但是粘结剂为聚(丙烯酸-甲基丙烯酸乙酯)，具体参数如表3所示，制备方法如下：The preparation method of the battery of Comparative Example 3 is similar to that of the battery of Example 1, but the binder is poly(acrylic acid-ethyl methacrylate), the specific parameters are shown in Table 3, and the preparation method is as follows:
以8:1的摩尔比分别称取丙烯酸以及甲基丙烯酸乙酯，量取500ml四氢呋喃，加入四口烧瓶，通入大量氮气，并逐渐加大搅拌速度，至1200转/分钟，加入单体质量1％的RAFT链转移剂(CTA-炔烃)和单体质量0.1％的偶氮二异丁腈，升温至60℃。反应7小时后，通过在液氮中冷却终止反应，溶液在过量的甲醇中沉淀。通过过滤收集聚合物，并用甲醇从氯仿中再沉淀两次。将所得聚合物在室温下真空干燥过夜以除去所有痕量的残留溶剂，得到目标粘结剂。Acrylic acid and ethyl methacrylate were weighed in a molar ratio of 8:1, 500ml of tetrahydrofuran was measured, added to a four-necked flask, a large amount of nitrogen was introduced, and the stirring speed was gradually increased to 1200 rpm, 1% of the monomer mass of RAFT chain transfer agent (CTA-alkyne) and 0.1% of the monomer mass of azobisisobutyronitrile were added, and the temperature was raised to 60°C. After reacting for 7 hours, the reaction was terminated by cooling in liquid nitrogen, and the solution was precipitated in excess methanol. The polymer was collected by filtration and reprecipitated twice from chloroform with methanol. The resulting polymer was vacuum dried overnight at room temperature to remove all traces of residual solvent to obtain the target binder.
对比例4Comparative Example 4
对比例4的电池与实施例1的电池制备方法相似，但是粘结剂为聚(丙烯酸-丙烯腈-甲基丙烯酸乙酯)，具体参数如表3所示，制备方法如下：The preparation method of the battery of Comparative Example 4 is similar to that of the battery of Example 1, but the binder is poly(acrylic acid-acrylonitrile-ethyl methacrylate), the specific parameters are shown in Table 3, and the preparation method is as follows:
以8:1:1的摩尔比分别称取丙烯酸、甲基丙烯酸乙酯以及丙烯腈，量取500ml四氢呋喃，加入四口烧瓶，通入大量氮气，并逐渐加大搅拌速度，至1200转/分钟，加入单体质量1％的RAFT链转移剂(CTA-炔烃)和单体质量0.1％的偶氮二异丁腈，升温至60℃。反应7小时后，通过在液氮中冷却终止反应，溶液在过量的甲醇中沉淀。通过过滤收集聚合物，并用甲醇从氯仿中再沉淀两次。将所得聚合物在室温下真空干燥过夜以除去所有痕量的残留溶剂，得到目标粘结剂。Acrylic acid, ethyl methacrylate and acrylonitrile were weighed in a molar ratio of 8:1:1, 500ml of tetrahydrofuran was measured, added to a four-necked flask, a large amount of nitrogen was introduced, and the stirring speed was gradually increased to 1200 rpm, 1% of the monomer mass of RAFT chain transfer agent (CTA-alkyne) and 0.1% of the monomer mass of azobisisobutyronitrile were added, and the temperature was raised to 60°C. After reacting for 7 hours, the reaction was terminated by cooling in liquid nitrogen, and the solution was precipitated in excess methanol. The polymer was collected by filtration and reprecipitated twice from chloroform with methanol. The resulting polymer was vacuum dried overnight at room temperature to remove all traces of residual solvent to obtain the target binder.
对比例5Comparative Example 5
对比例5的电池与实施例1的电池制备方法相似，但是粘结剂为聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)，具体参数如表3所示，制备 方法如下：The battery of Comparative Example 5 is prepared in a similar manner to the battery of Example 1, but the binder is poly(acrylic acid-acrylamide-ethyl methacrylate). The specific parameters are shown in Table 3. Methods as below:
以8:1:1的摩尔比分别称取丙烯酸、甲基丙烯酸乙酯以及丙烯酰胺，量取500ml四氢呋喃，加入四口烧瓶，通入大量氮气，并逐渐加大搅拌速度，至1200转/分钟，加入单体质量1％的RAFT链转移剂(CTA-炔烃)和单体质量0.1％的偶氮二异丁腈，升温至60℃。反应7小时后，通过在液氮中冷却终止反应，溶液在过量的甲醇中沉淀。通过过滤收集聚合物，并用甲醇从氯仿中再沉淀两次。将所得聚合物在室温下真空干燥过夜以除去所有痕量的残留溶剂，得到目标粘结剂。Acrylic acid, ethyl methacrylate and acrylamide were weighed in a molar ratio of 8:1:1, 500 ml of tetrahydrofuran was measured, added to a four-necked flask, a large amount of nitrogen was introduced, and the stirring speed was gradually increased to 1200 rpm, 1% of the monomer mass of RAFT chain transfer agent (CTA-alkyne) and 0.1% of the monomer mass of azobisisobutyronitrile were added, and the temperature was raised to 60 ° C. After reacting for 7 hours, the reaction was terminated by cooling in liquid nitrogen, and the solution was precipitated in excess methanol. The polymer was collected by filtration and reprecipitated twice from chloroform with methanol. The resulting polymer was vacuum dried overnight at room temperature to remove all traces of residual solvent to obtain the target binder.
对比例6Comparative Example 6
对比例6的电池与实施例1的电池制备方法相似，但是粘结剂为聚偏二氟乙烯与聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)的共混物，具体参数如表3所示，制备方法如下：The preparation method of the battery of Comparative Example 6 is similar to that of the battery of Example 1, but the binder is a blend of polyvinylidene fluoride and poly(acrylic acid-acrylamide-ethyl methacrylate), the specific parameters are shown in Table 3, and the preparation method is as follows:
共混：将对比例5中的聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)与对比例1中聚偏二氟乙烯共混按照摩尔比例6:4进行共混，得到聚偏二氟乙烯与聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)的共混物粘结剂。Blending: The poly(acrylic acid-acrylamide-ethyl methacrylate) in Comparative Example 5 and the polyvinylidene fluoride in Comparative Example 1 are blended in a molar ratio of 6:4 to obtain a blend adhesive of polyvinylidene fluoride and poly(acrylic acid-acrylamide-ethyl methacrylate).
对比例7Comparative Example 7
对比例7的电池与实施例1的电池制备方法相似，但是粘结剂为聚偏二氟乙烯与聚丙烯酸的共混物，具体参数如表3所示，制备方法如下：The preparation method of the battery of Comparative Example 7 is similar to that of the battery of Example 1, but the binder is a blend of polyvinylidene fluoride and polyacrylic acid. The specific parameters are shown in Table 3. The preparation method is as follows:
共混：将对比例2中的聚丙烯酸与对比例1中聚偏二氟乙烯共混按照摩尔比例6:4进行共混，得到聚偏二氟乙烯与聚丙烯酸-的共混物粘结剂。Blending: The polyacrylic acid in Comparative Example 2 and the polyvinylidene fluoride in Comparative Example 1 are blended in a molar ratio of 6:4 to obtain a blend adhesive of polyvinylidene fluoride and polyacrylic acid.
二、性能测试2. Performance Test
1、浆料性能测试1. Slurry performance test
1)浆料粘度测试1) Slurry viscosity test
浆料出货后，取500ml浆料放置在烧杯中，利用旋转粘度计，选取转子，转速设置为12转/分钟，转动时间设置为5分钟，数值稳定后，读取并记录粘度数值。 After the slurry is shipped, take 500 ml of the slurry and place it in a beaker. Use a rotational viscometer, select the rotor, set the speed to 12 rpm, and set the rotation time to 5 minutes. After the value stabilizes, read and record the viscosity value.
2)浆料稳定性测试2) Slurry stability test
将浆料复搅30分钟后，取一定量的浆料倒入稳定性仪的样品瓶，放入样品瓶后，关闭测试塔盖，打开测试塔盖，测试界面开始出现扫描曲线，开始测试样品稳定性，持续测试48小时以上完成测试。After re-stirring the slurry for 30 minutes, take a certain amount of slurry and pour it into the sample bottle of the stability instrument. After putting it into the sample bottle, close the test tower cover, open the test tower cover, and a scanning curve will begin to appear on the test interface, and the sample stability test will begin. The test will be completed after more than 48 hours of continuous testing.
2、极片性能测试2. Pole performance test
1)膜片电阻测试1) Diaphragm resistance test
将极片左、中、右处裁剪直径20mm小圆片。打开元能科技极片电阻仪指示灯，将置于膜片电阻仪“探头”合适位置，点击“开始”按钮，待示数稳定，读取即可。每个小圆片测试两个位置，最后计算六次测量的平均值，即为该极片的膜片电阻。Cut small discs with a diameter of 20mm from the left, middle and right sides of the electrode. Turn on the indicator light of Yuanneng Technology's electrode resistor meter, place the probe in the appropriate position of the membrane resistor meter, click the "start" button, and wait for the reading to stabilize before reading. Test two positions of each small disc, and finally calculate the average value of six measurements, which is the membrane resistance of the electrode.
2)粘结力测试2) Adhesion test
将正极极片裁剪为20mm×100mm尺寸的测试试样，备用；极片用双面胶粘接正极膜层一面，并用压辊压实，使双面胶与极片完全贴合；双面胶的另外一面粘贴于不锈钢表面，将试样一端反向弯曲，弯曲角度为180°；采用高铁拉力机测试，将不锈钢一端固定于拉力机下方夹具，试样弯曲末端固定于上方夹具，调整试样角度，保证上下端位于垂直位置，然后以50mm/min的速度拉伸试样，直到集流体全部从正极膜片剥离，记录过程中的位移和作用力。以受力平衡时的力除以与双面胶贴合的极片的宽度(极片的宽度方向垂直于剥离方向)作为单位长度的极片的粘结力，本测试中与双面胶贴合的极片的宽度为20mm。The positive electrode sheet was cut into a test sample of 20mm×100mm size for standby use; the sheet was bonded to one side of the positive electrode film layer with double-sided tape, and compacted with a roller to make the double-sided tape and the sheet completely fit; the other side of the double-sided tape was pasted to the stainless steel surface, and one end of the sample was bent in the opposite direction with a bending angle of 180°; the high-speed rail tensile machine was used for testing, one end of the stainless steel was fixed to the lower fixture of the tensile machine, and the bent end of the sample was fixed to the upper fixture, and the angle of the sample was adjusted to ensure that the upper and lower ends were in a vertical position, and then the sample was stretched at a speed of 50mm/min until the current collector was completely peeled off from the positive electrode film, and the displacement and force during the process were recorded. The force at the time of force balance divided by the width of the sheet bonded to the double-sided tape (the width direction of the sheet is perpendicular to the peeling direction) is taken as the bonding force of the sheet per unit length. In this test, the width of the sheet bonded to the double-sided tape is 20mm.
3)柔性测试(弯曲测试)3)Flexibility test (bending test)
将冷压后的正极极片裁剪为20mm×100mm尺寸的测试试样；将其正向对折后，用2kg压辊压平，并展开对着光检查缝隙是否出现透光，如未出现透光，则反向对折，用2kg压辊压平，并对着光再次检查，如此反复直至，缝隙出现透光现象，记录对折次数；重复三次测试，并取平均值，作为极片柔性的参考数据。The cold-pressed positive electrode sheet is cut into test specimens of 20mm×100mm size; after folding it in the forward direction, it is flattened with a 2kg roller, and unfolded to check whether there is light transmittance through the gap. If there is no light transmittance, fold it in the reverse direction, flatten it with a 2kg roller, and check again against the light. Repeat this process until light transmittance appears in the gap, and record the number of folding times; repeat the test three times, and take the average value as the reference data for the flexibility of the electrode sheet.
3、电池性能测试 3. Battery performance test
1)电池循环容量保持率(500ds)测试1) Battery cycle capacity retention rate (500ds) test
电池容量保持率测试过程如下：在25℃下，将制备的电池，以1/3C恒流充电至4.3V，再以4.3V恒定电压充电至电流为0.05C，搁置5min，再以1/3C放电至2.8V，所得容量记为初始容量C0。对上述同一个电池重复以上步骤，并同时记录循环第n次后电池的放电容量Cn，则每次循环后电池容量保持率Pn＝Cn/C0×100％，以P1、P2……P500这500个点值为纵坐标，以对应的循环次数为横坐标，得到电池容量保持率与循环次数的曲线图。该测试过程中，第一次循环对应n＝1、第二次循环对应n＝2、……第500次循环对应n＝500。表4中实施例或对比例对应的电池容量保持率数据是在上述测试条件下循环500次之后测得的数据，即P500的值。对比例以及其他实施例的测试过程同上。The battery capacity retention rate test process is as follows: at 25°C, the prepared battery is charged to 4.3V at a constant current of 1/3C, then charged to a current of 0.05C at a constant voltage of 4.3V, left for 5 minutes, and then discharged to 2.8V at 1/3C. The obtained capacity is recorded as the initial capacity C0. Repeat the above steps for the same battery mentioned above, and record the discharge capacity Cn of the battery after the nth cycle at the same time. Then, after each cycle, the battery capacity retention rate Pn=Cn/C0×100%, with the 500 point values of P1, P2...P500 as the ordinate, and the corresponding number of cycles as the abscissa, to obtain a curve chart of the battery capacity retention rate and the number of cycles. During the test, the first cycle corresponds to n=1, the second cycle corresponds to n=2, and...the 500th cycle corresponds to n=500. The battery capacity retention rate data corresponding to the embodiment or comparative example in Table 4 is the data measured after 500 cycles under the above test conditions, that is, the value of P500. The test process of the comparative example and other embodiments is the same as above.
2)电池直流阻抗增长率(100cls)测试2) Battery DC impedance growth rate (100cls) test
电池直流阻抗测试过程如下：在25℃下，将电池，以1/3C恒流充电至4.3V，再以4.3V恒定电压充电至电流为0.05C，搁置5min后，记录电压V1。然后再以1/3C放电30s，记录电压V2，则(V2-V1)/(1/3C)，得到第一次循环后电池的内阻DCR1。对上述同一个电池重复以上步骤，并同时记录循环第n次后电池的内阻DCRn(n＝1、2、3……100)，将上述DCR1、DCR2、DCR3……DCR100这100个点值为纵坐标，以对应的循环次数为横坐标，得到电池放电DCR与循环次数的曲线图。The battery DC impedance test process is as follows: at 25°C, charge the battery at a constant current of 1/3C to 4.3V, then charge at a constant voltage of 4.3V to a current of 0.05C, leave it for 5 minutes, and record the voltage V1. Then discharge it at 1/3C for 30s, record the voltage V2, and then (V2-V1)/(1/3C) is the internal resistance DCR1 of the battery after the first cycle. Repeat the above steps for the same battery, and record the internal resistance DCRn (n=1, 2, 3...100) of the battery after the nth cycle at the same time, and use the 100 point values of DCR1, DCR2, DCR3...DCR100 as the vertical coordinates, and the corresponding number of cycles as the horizontal coordinates to obtain a curve chart of battery discharge DCR and cycle number.
该测试过程中，第一次循环对应n＝1、第二次循环对应n＝2、……第100次循环对应n＝100。表4中实施例1的电池内阻增大比率＝(DCRn-DCR1)/DCR1×100％，对比例以及其他实施例的测试过程同上。表4中的数据是在上述测试条件下循环100次之后测得的数据。In this test process, the first cycle corresponds to n=1, the second cycle corresponds to n=2, ... the 100th cycle corresponds to n=100. The battery internal resistance increase ratio of Example 1 in Table 4 = (DCRn-DCR1)/DCR1×100%, and the test process of the comparative example and other examples is the same as above. The data in Table 4 are measured after 100 cycles under the above test conditions.
4、聚合物检测4. Polymer detection
1)重均分子量(W g/mol)测试方法 1) Weight average molecular weight (W g/mol) test method
采用Waters 2695 Isocratic HPLC型凝胶色谱仪(示差折光检测器2141)。质量分数为3.0％的聚苯乙烯溶液试样做参比，选择匹配的色谱柱(油性：Styragel HT5 DMF7.8*300mm+Styragel HT4)。用纯化后的N-甲基吡咯烷酮(NMP)溶剂配置3.0％的聚合物胶液，配置好的溶液静置一天，备用。测试时，先用注射器吸取四氢呋喃，进行冲洗，重复几次。然后吸取5ml实验溶液，排除注射器中的空气，将针尖擦干。最后将试样溶液缓缓注入进样口。待示数稳定后获取数据。A Waters 2695 Isocratic HPLC gel chromatograph (differential refractive index detector 2141) was used. A polystyrene solution sample with a mass fraction of 3.0% was used as a reference, and a matching chromatographic column (oily: Styragel HT5 DMF7.8*300mm+Styragel HT4) was selected. A 3.0% polymer gel solution was prepared with purified N-methylpyrrolidone (NMP) solvent, and the prepared solution was allowed to stand for one day for use. During the test, tetrahydrofuran was first drawn with a syringe, rinsed, and repeated several times. Then 5 ml of the experimental solution was drawn, the air in the syringe was removed, and the needle tip was wiped dry. Finally, the sample solution was slowly injected into the injection port. Data was obtained after the indication was stable.
三、各实施例、对比例测试结果分析 III. Analysis of test results of various embodiments and comparative examples
表3实施例和对比例制备参数与重均分子量测试结果







Table 3 Preparation parameters and weight average molecular weight test results of examples and comparative examples







表4实施例和对比例的性能测试结果







Table 4 Performance test results of embodiments and comparative examples







根据上述结果可知，实施例1-45中的粘结剂均包含聚合物，聚合物均包含A-嵌段和B-嵌段，其中实施例1-24的A-嵌段含有衍生自式I所示单体的结构单元，B-嵌段含有衍生自式II所示单体的结构单元或者含有衍生自式II所示单体的结构单元和衍生自式III所示单体的结构单元。实施例25-45的A嵌段含有衍生自式II所示单体的结构单元或者含有衍生自式II所示单体的结构单元和衍生自式III所示单体的结构单元，B嵌段含有衍生自式I所示单体的结构单元。从实施例1-7、16-31、40-45和对比例1的对比可见，该粘结剂能够有效减缓浆料的凝胶现象，提高浆料的稳定性，提高极片的柔性，提高粘结力，降低膜片电阻，降低电池的直流阻抗增长率，和/或提高电池的循环容量保持率。According to the above results, the binders in Examples 1-45 all contain polymers, and the polymers all contain A-blocks and B-blocks, wherein the A-blocks of Examples 1-24 contain structural units derived from monomers shown in Formula I, and the B-blocks contain structural units derived from monomers shown in Formula II or structural units derived from monomers shown in Formula II and structural units derived from monomers shown in Formula III. The A blocks of Examples 25-45 contain structural units derived from monomers shown in Formula II or structural units derived from monomers shown in Formula II and structural units derived from monomers shown in Formula III, and the B blocks contain structural units derived from monomers shown in Formula I. From the comparison of Examples 1-7, 16-31, 40-45 and Comparative Example 1, it can be seen that the binder can effectively slow down the gelation of the slurry, improve the stability of the slurry, improve the flexibility of the pole piece, improve the bonding force, reduce the membrane resistance, reduce the DC impedance growth rate of the battery, and/or improve the cycle capacity retention rate of the battery.
从实施例1-7和18-23与对比例1的对比可见，A-嵌段衍生自式I所示单体的结构单元的摩尔含量为30％-70％时，基于所述嵌段共聚物中所有结构单元的总摩尔数计，能够有效减缓浆料的凝胶现象，提 高浆料的稳定性，提高极片的柔性，降低膜片电阻，并提高电池的循环容量保持率。From the comparison between Examples 1-7 and 18-23 and Comparative Example 1, it can be seen that when the molar content of the structural unit derived from the monomer represented by Formula I in the A-block is 30%-70%, based on the total molar number of all structural units in the block copolymer, the gelation phenomenon of the slurry can be effectively slowed down, and the High slurry stability improves the flexibility of the electrode, reduces the membrane resistance, and improves the battery's cycle capacity retention rate.
从实施例25-31和实施例43-45与对比例1对比可见，B-嵌段中衍生自式I所示单体的结构单元的摩尔含量为30％-70％时，基于所述嵌段共聚物中所有结构单元的总摩尔数计，能够减缓浆料的凝胶现象，提高浆料的稳定性，降低极片的膜片电阻，降低电池的直流阻抗增长率。From the comparison of Examples 25-31 and Examples 43-45 with Comparative Example 1, it can be seen that when the molar content of the structural unit derived from the monomer represented by Formula I in the B-block is 30%-70%, based on the total molar number of all structural units in the block copolymer, the gelation of the slurry can be slowed down, the stability of the slurry can be improved, the diaphragm resistance of the pole piece can be reduced, and the DC impedance growth rate of the battery can be reduced.
从实施例1-11、25-35与对比例6的对比可见，粘结剂的重均分子量为40万-200万时，能够有效减缓浆料的凝胶现象，提高浆料的稳定性，提高极片的柔性，提高粘结力，降低膜片电阻，降低电池的直流阻抗增长率，并提高电池的循环容量保持率。从实施例1-7、25-31和10-11、34-35与对比例1、5和6的对比可见，粘结剂的重均分子量为120万-200万时，能够提高极片的柔性，并提高粘结力。从实施例1-7、25-31和10、34与对比例1、5和6的对比可见，粘结剂的重均分子量为120万-150万时，能够提高极片的柔性，提高粘结力，并提高电池的循环容量保持率。From the comparison of Examples 1-11, 25-35 and Comparative Example 6, it can be seen that when the weight average molecular weight of the binder is 400,000-2 million, it can effectively slow down the gelation phenomenon of the slurry, improve the stability of the slurry, improve the flexibility of the pole piece, improve the bonding force, reduce the membrane resistance, reduce the DC impedance growth rate of the battery, and improve the battery's cycle capacity retention rate. From the comparison of Examples 1-7, 25-31 and 10-11, 34-35 and Comparative Examples 1, 5 and 6, it can be seen that when the weight average molecular weight of the binder is 1.2 million-2 million, it can improve the flexibility of the pole piece and improve the bonding force. From the comparison of Examples 1-7, 25-31 and 10, 34 and Comparative Examples 1, 5 and 6, it can be seen that when the weight average molecular weight of the binder is 1.2 million-1.5 million, it can improve the flexibility of the pole piece, improve the bonding force, and improve the battery's cycle capacity retention rate.
从实施例1-7和18-23与对比例1的对比可见，含有衍生自式I所示单体的结构单元的A-嵌段的重均分子量为20万-105万时，能够有效减缓浆料的凝胶现象，提高浆料的稳定性，提高极片的柔性，降低膜片电阻，并提高电池的循环容量保持率。从实施例25-31和实施例40-42与对比例5的对比可见，含有衍生自式II所示单体的结构单元或者含有衍生自式II所示单体的结构单元和衍生自式III所示单体的结构单元的A-嵌段的重均分子量为20万-105万时，能够提高极片的粘结力，降低电池的直流阻抗增长率。From the comparison of Examples 1-7 and 18-23 with Comparative Example 1, it can be seen that when the weight average molecular weight of the A-block containing the structural unit derived from the monomer shown in Formula I is 200,000-1,050,000, it can effectively slow down the gelation of the slurry, improve the stability of the slurry, improve the flexibility of the pole piece, reduce the membrane resistance, and improve the cycle capacity retention rate of the battery. From the comparison of Examples 25-31 and Examples 40-42 with Comparative Example 5, it can be seen that when the weight average molecular weight of the A-block containing the structural unit derived from the monomer shown in Formula II or the structural unit derived from the monomer shown in Formula II and the structural unit derived from the monomer shown in Formula III is 200,000-1,050,000, it can improve the bonding force of the pole piece and reduce the DC impedance growth rate of the battery.
从实施例1-7、16-17和24与对比例5的对比可见，B-嵌段的重均分子量为10万-50万时，能够提高粘结力，并提高电池的循环容量保持率。从实施例25-31和实施例43-45与对比例1对比可见，B-嵌 段的重均分子量为10万-50万时，能够有效减缓浆料的凝胶现象，提高浆料的稳定性，降低膜片电阻，降低电池的直流阻抗增长率。From the comparison between Examples 1-7, 16-17 and 24 and Comparative Example 5, it can be seen that when the weight average molecular weight of the B-block is 100,000-500,000, the adhesion can be improved and the cycle capacity retention rate of the battery can be improved. From the comparison between Examples 25-31 and Examples 43-45 and Comparative Example 1, it can be seen that the B-block When the weight average molecular weight of the segment is 100,000-500,000, it can effectively slow down the gelation phenomenon of the slurry, improve the stability of the slurry, reduce the membrane resistance, and reduce the DC impedance growth rate of the battery.
从实施例1-7、16-17和24与对比例5的对比可见，A-嵌段中的式I所示的单体选自偏氟乙烯、四氟乙烯、氟乙烯、六氟丙烯中的一种或多种时，特别地，A-嵌段选自聚偏氟乙烯、聚四氟乙烯、聚氟乙烯、聚(偏二氟乙烯-六氟丙烯)中的一种或多种时，能够提高粘结力，并提高电池的循环容量保持率。从实施例25-31、40-42与对比例5的对比可见，B-嵌段中的式I所示的单体选自偏氟乙烯、四氟乙烯、氟乙烯、六氟丙烯中的一种或多种时，特别地，B-嵌段选自聚偏氟乙烯、聚四氟乙烯、聚氟乙烯、聚(偏二氟乙烯-六氟丙烯)中的一种或多种时，能够提高极片的粘结力，降低电池的直流阻抗增长率。From the comparison of Examples 1-7, 16-17 and 24 with Comparative Example 5, it can be seen that when the monomer shown in Formula I in the A-block is selected from one or more of vinylidene fluoride, tetrafluoroethylene, vinyl fluoride, and hexafluoropropylene, in particular, when the A-block is selected from one or more of polyvinylidene fluoride, polytetrafluoroethylene, polyvinyl fluoride, and poly (vinylidene fluoride-hexafluoropropylene), the bonding force can be improved and the cycle capacity retention rate of the battery can be improved. From the comparison of Examples 25-31, 40-42 with Comparative Example 5, it can be seen that when the monomer shown in Formula I in the B-block is selected from one or more of vinylidene fluoride, tetrafluoroethylene, vinyl fluoride, and hexafluoropropylene, in particular, when the B-block is selected from one or more of polyvinylidene fluoride, polytetrafluoroethylene, polyvinyl fluoride, and poly (vinylidene fluoride-hexafluoropropylene), the bonding force of the pole piece can be improved and the DC impedance growth rate of the battery can be reduced.
从实施例1-7和18-23与对比例1的对比可见，B嵌段中的式II所示单体选自丙烯酸、甲基丙烯酸、乙基丙烯酸中的一种或多种，B-嵌段中的式III所示单体选自丙烯酰胺、丙烯酸酯、丙烯腈中的一种或多种，特别地B-嵌段中的式III所示单体选自丙烯酰胺、甲基丙烯酸乙酯、丙烯腈中的一种或多种时，特别地，B-嵌段选自聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)、聚(丙烯酸-丙烯腈-甲基丙烯酸乙酯)、聚丙烯酸、聚(丙烯酸-甲基丙烯酸乙酯)、聚(丙烯酸-丙烯腈)、聚(丙烯酸-丙烯酰胺)、聚(丙烯酸-丙烯腈-丙烯酰胺)中的一种或多种时，能够有效减缓浆料的凝胶现象，提高浆料的稳定性，提高极片的柔性，降低膜片电阻，并提高电池的循环容量保持率。实施例5、18和20-23与对比例1的对比可见，B-嵌段选自聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)、聚(丙烯酸-丙烯腈-甲基丙烯酸乙酯)、聚丙烯酸、聚(丙烯酸-丙烯腈)、聚(丙烯酸-丙烯酰胺)、聚(丙烯酸-丙烯腈-丙烯酰胺)中的一种或多种时，能够有效减缓浆料的凝胶现象，提高浆料的稳定性，提高极片的柔性，提高粘结力，降低膜片电阻，并提高电池的循环容量保持率。实施例5和18、21-23与对比例1的对比可见，B-嵌段选自聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)、聚(丙烯酸-丙烯腈-甲 基丙烯酸乙酯)、聚(丙烯酸-丙烯腈)、聚(丙烯酸-丙烯酰胺)、聚(丙烯酸-丙烯腈-丙烯酰胺)中的一种或多种时，能够有效减缓浆料的凝胶现象，提高浆料的稳定性，提高极片的柔性，提高粘结力，降低膜片电阻，降低电池的直流阻抗增长率，并提高电池的循环容量保持率。From the comparison of Examples 1-7 and 18-23 with Comparative Example 1, it can be seen that the monomer represented by formula II in the B block is selected from one or more of acrylic acid, methacrylic acid, and ethacrylic acid, and the monomer represented by formula III in the B block is selected from one or more of acrylamide, acrylate, and acrylonitrile. In particular, when the monomer represented by formula III in the B block is selected from one or more of acrylamide, ethyl methacrylate, and acrylonitrile, in particular, when the B block is selected from one or more of poly(acrylic acid-acrylamide-ethyl methacrylate), poly(acrylic acid-acrylonitrile-ethyl methacrylate), polyacrylic acid, poly(acrylic acid-ethyl methacrylate), poly(acrylic acid-acrylonitrile), poly(acrylic acid-acrylamide), and poly(acrylic acid-acrylonitrile-acrylamide), the gel phenomenon of the slurry can be effectively slowed down, the stability of the slurry can be improved, the flexibility of the electrode sheet can be improved, the membrane resistance can be reduced, and the cycle capacity retention rate of the battery can be improved. Comparison of Examples 5, 18, and 20-23 with Comparative Example 1 shows that when the B-block is selected from one or more of poly(acrylic acid-acrylamide-ethyl methacrylate), poly(acrylic acid-acrylonitrile-ethyl methacrylate), polyacrylic acid, poly(acrylic acid-acrylonitrile), poly(acrylic acid-acrylamide), and poly(acrylic acid-acrylonitrile-acrylamide), it can effectively slow down the gelation of the slurry, improve the stability of the slurry, improve the flexibility of the pole piece, improve the bonding force, reduce the membrane resistance, and improve the cycle capacity retention rate of the battery. Comparison of Examples 5, 18, and 21-23 with Comparative Example 1 shows that when the B-block is selected from one or more of poly(acrylic acid-acrylamide-ethyl methacrylate), poly(acrylic acid-acrylonitrile-ethyl methacrylate), polyacrylic acid, poly(acrylic acid-acrylonitrile), poly(acrylic acid-acrylamide), and poly(acrylic acid-acrylonitrile-acrylamide), it can effectively slow down the gelation of the slurry, improve the stability of the slurry, improve the flexibility of the pole piece, improve the bonding force, reduce the membrane resistance, and improve the cycle capacity retention rate of the battery. When one or more of poly(ethyl acrylate), poly(acrylic acid-acrylonitrile), poly(acrylic acid-acrylamide), and poly(acrylic acid-acrylonitrile-acrylamide) are added, the gelation phenomenon of the slurry can be effectively slowed down, the stability of the slurry can be improved, the flexibility of the electrode sheet can be improved, the bonding force can be improved, the membrane resistance can be reduced, the DC impedance growth rate of the battery can be reduced, and the cycle capacity retention rate of the battery can be improved.
从实施例25-31、43-45与对比例1对比可见，A-嵌段中的式II所示单体选自丙烯酸、甲基丙烯酸、乙基丙烯酸中的一种或多种，A-嵌段中的式III所示单体选自丙烯酰胺、丙烯酸酯、丙烯腈中的一种或多种，特别地A-嵌段中的式III所示单体选自丙烯酰胺、甲基丙烯酸乙酯、丙烯腈中的一种或多种时，特别地，A-嵌段选自聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)、聚丙烯酸、聚(丙烯酸-丙烯酰胺)、聚(丙烯酸-丙烯腈-丙烯酰胺)中的一种或多种时，能够有效减缓浆料的凝胶现象，提高浆料的稳定性，降低膜片电阻，降低电池的直流阻抗增长率。实施例25-31和43与对比例1的对比可见，A-嵌段选自聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)、聚丙烯酸中的一种或多种时，能够有效减缓浆料的凝胶现象，提高浆料的稳定性，提高极片的柔性，提高粘结力，降低膜片电阻，并降低电池的直流阻抗增长率，提高电池的循环容量保持率。From the comparison of Examples 25-31, 43-45 and Comparative Example 1, it can be seen that the monomer represented by Formula II in the A-block is selected from one or more of acrylic acid, methacrylic acid, and ethacrylic acid, and the monomer represented by Formula III in the A-block is selected from one or more of acrylamide, acrylate, and acrylonitrile. In particular, when the monomer represented by Formula III in the A-block is selected from one or more of acrylamide, ethyl methacrylate, and acrylonitrile, in particular, when the A-block is selected from one or more of poly(acrylic acid-acrylamide-ethyl methacrylate), polyacrylic acid, poly(acrylic acid-acrylamide), and poly(acrylic acid-acrylonitrile-acrylamide), it can effectively slow down the gelation of the slurry, improve the stability of the slurry, reduce the membrane resistance, and reduce the DC impedance growth rate of the battery. From the comparison of Examples 25-31 and 43 with Comparative Example 1, it can be seen that when the A-block is selected from one or more of poly(acrylic acid-acrylamide-ethyl methacrylate) and polyacrylic acid, it can effectively slow down the gelation of the slurry, improve the stability of the slurry, improve the flexibility of the pole piece, improve the bonding force, reduce the membrane resistance, and reduce the DC impedance growth rate of the battery, and improve the cycle capacity retention rate of the battery.
从实施例1-7和16-23与对比例1的对比可见，嵌段共聚物为聚丙烯酸-聚偏二氟乙烯-聚丙烯酸三嵌段共聚物、聚(丙烯酸-甲基丙烯酸乙酯)-聚偏二氟乙烯-聚(丙烯酸-甲基丙烯酸乙酯)三嵌段共聚物、聚(丙烯酸-丙烯腈-甲基丙烯酸乙酯)-聚偏二氟乙烯-聚(丙烯酸-丙烯腈-甲基丙烯酸乙酯)三嵌段共聚物、聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)-聚偏二氟乙烯-聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)三嵌段共聚物、聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)-聚氟乙烯-聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)三嵌段共聚物、聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)-聚四氟乙烯-聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)三嵌段共聚物、聚(丙烯酸-丙烯腈)-聚偏二氟乙烯-聚(丙烯酸-丙烯腈)三嵌段共聚物、聚(丙烯酸-丙烯酰胺)-聚偏二氟乙烯-聚(丙烯酸-丙烯酰胺)三嵌 段共聚物、聚(丙烯酸-丙烯腈-丙烯酰胺)-聚偏二氟乙烯-聚(丙烯酸-丙烯腈-丙烯酰胺)三嵌段共聚物、聚(丙烯酸-丙烯酰胺-丙烯酸酯)-聚(偏二氟乙烯-六氟丙烯)-聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)中的一种或多种时，能够有效减缓浆料的凝胶现象，提高浆料的稳定性，提高极片的柔性，提高粘结力，降低膜片电阻，降低电池的直流阻抗增长率，和/或提高电池的循环容量保持率。从实施例1-7与对比例1、5和6的对比可见，嵌段共聚物为聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)-聚偏二氟乙烯-聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)三嵌段共聚物时，能够提高极片的柔性，提高粘结力，并提高电池的循环容量保持率。从实施例16-17、24与对比例5的对比可见，嵌段共聚物为聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)-聚氟乙烯-聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)三嵌段共聚物、聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)-聚四氟乙烯-聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)三嵌段共聚物、聚(丙烯酸-丙烯酰胺-丙烯酸酯)-聚(偏二氟乙烯-六氟丙烯)-聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)中的一种或多种时，能够提高粘结力，并提高电池的循环容量保持率。从实施例18与对比例1和4的对比可见，嵌段共聚物为聚(丙烯酸-丙烯腈-甲基丙烯酸乙酯)-聚偏二氟乙烯-聚(丙烯酸-丙烯腈-甲基丙烯酸乙酯)三嵌段共聚物时，能够提高粘结力，降低电池的直流阻抗增长率，并提高电池的循环容量保持率。从实施例19与对比例1和3的对比可见，嵌段共聚物为聚(丙烯酸-甲基丙烯酸乙酯)-聚偏二氟乙烯-聚(丙烯酸-甲基丙烯酸乙酯)三嵌段共聚物时，能够提高极片的柔性，降低电池的直流阻抗增长率，并提高电池的循环容量保持率。从实施例20与对比例1-2、7的对比可见，嵌段共聚物为聚丙烯酸-聚偏二氟乙烯-聚丙烯酸三嵌段共聚物时，能够提高粘结力，并提高电池的循环容量保持率。From the comparison between Examples 1-7 and 16-23 and Comparative Example 1, it can be seen that the block copolymers are polyacrylic acid-polyvinylidene fluoride-polyacrylic acid triblock copolymer, poly(acrylic acid-ethyl methacrylate)-polyvinylidene fluoride-poly(acrylic acid-ethyl methacrylate) triblock copolymer, poly(acrylic acid-acrylonitrile-ethyl methacrylate)-polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-ethyl methacrylate) triblock copolymer, poly(acrylic acid-acrylamide-ethyl methacrylate)-polyvinylidene fluoride-poly(acrylic acid-acrylamide-ethyl methacrylate) triblock copolymers of poly(acrylic acid-acrylamide-ethyl methacrylate)-polyvinyl fluoride-poly(acrylic acid-acrylamide-ethyl methacrylate) triblock copolymers, poly(acrylic acid-acrylamide-ethyl methacrylate)-polytetrafluoroethylene-poly(acrylic acid-acrylamide-ethyl methacrylate) triblock copolymers, poly(acrylic acid-acrylonitrile)-polyvinylidene fluoride-poly(acrylic acid-acrylonitrile) triblock copolymers, poly(acrylic acid-acrylamide)-polyvinylidene fluoride-poly(acrylic acid-acrylamide) triblock copolymers When the block copolymer is one or more of poly(acrylic acid-acrylonitrile-acrylamide)-polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylamide) triblock copolymer, poly(acrylic acid-acrylamide-acrylate)-poly(vinylidene fluoride-hexafluoropropylene)-poly(acrylic acid-acrylamide-ethyl methacrylate), the gelation phenomenon of the slurry can be effectively slowed down, the stability of the slurry can be improved, the flexibility of the pole piece can be improved, the bonding force can be improved, the membrane resistance can be reduced, the DC impedance growth rate of the battery can be reduced, and/or the cycle capacity retention rate of the battery can be improved. From the comparison of Examples 1-7 with Comparative Examples 1, 5 and 6, it can be seen that when the block copolymer is a triblock copolymer of poly(acrylic acid-acrylamide-ethyl methacrylate)-polyvinylidene fluoride-poly(acrylic acid-acrylamide-ethyl methacrylate), the flexibility of the pole piece can be improved, the bonding force can be improved, and the cycle capacity retention rate of the battery can be improved. From the comparison of Examples 16-17 and 24 with Comparative Example 5, it can be seen that when the block copolymer is a triblock copolymer of poly(acrylic acid-acrylamide-ethyl methacrylate)-polyvinyl fluoride-poly(acrylic acid-acrylamide-ethyl methacrylate), a triblock copolymer of poly(acrylic acid-acrylamide-ethyl methacrylate)-polytetrafluoroethylene-poly(acrylic acid-acrylamide-ethyl methacrylate), and a triblock copolymer of poly(acrylic acid-acrylamide-acrylate)-poly(vinylidene fluoride-hexafluoropropylene)-poly(acrylic acid-acrylamide-ethyl methacrylate), the adhesion can be improved, and the cycle capacity retention rate of the battery can be improved. From the comparison of Example 18 with Comparative Examples 1 and 4, it can be seen that when the block copolymer is a triblock copolymer of poly(acrylic acid-acrylonitrile-ethyl methacrylate)-polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-ethyl methacrylate), the adhesion can be improved, the DC impedance growth rate of the battery can be reduced, and the cycle capacity retention rate of the battery can be improved. From the comparison between Example 19 and Comparative Examples 1 and 3, it can be seen that when the block copolymer is a triblock copolymer of poly(acrylic acid-ethyl methacrylate)-polyvinylidene fluoride-poly(acrylic acid-ethyl methacrylate), the flexibility of the pole piece can be improved, the DC impedance growth rate of the battery can be reduced, and the cycle capacity retention rate of the battery can be improved. From the comparison between Example 20 and Comparative Examples 1-2 and 7, it can be seen that when the block copolymer is a triblock copolymer of polyacrylic acid-polyvinylidene fluoride-polyacrylic acid, the bonding force can be improved and the cycle capacity retention rate of the battery can be improved.
从实施例25-31与实施例40-45与对比例1对比可见，嵌段共聚物为聚偏二氟乙烯-聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)-聚偏二氟乙烯三嵌段共聚物、聚氟乙烯-聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)- 聚氟乙烯三嵌段共聚物、聚四氟乙烯-聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)-聚四氟乙烯三嵌段共聚物、聚(偏二氟乙烯-六氟丙烯)-聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)-聚(偏二氟乙烯-六氟丙烯)三嵌段共聚物、聚偏二氟乙烯-聚丙烯酸-聚偏二氟乙烯三嵌段共聚物、聚偏二氟乙烯-聚(丙烯酸-丙烯酰胺)-聚偏二氟乙烯三嵌段共聚物、聚偏二氟乙烯-聚(丙烯酸-丙烯腈-丙烯酰胺)-聚偏二氟乙烯三嵌段共聚物中的一种或多种，能够有效减缓浆料的凝胶现象，提高浆料的稳定性，提高极片的柔性，提高粘结力，降低膜片电阻，降低电池的直流阻抗增长率。从实施例25-31与对比例1、5和6的对比可见，嵌段共聚物为聚偏二氟乙烯-聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)-聚偏二氟乙烯三嵌段共聚物时，能够有效减缓浆料的凝胶现象，提高浆料的稳定性，提高极片的柔性，提高粘结力，并降低电池的直流阻抗增长率，提高电池的循环容量保持率。从实施例40-42与对比例5的对比可见，嵌段共聚物为聚氟乙烯-聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)-聚氟乙烯三嵌段共聚物、聚四氟乙烯-聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)-聚四氟乙烯、聚(偏二氟乙烯-六氟丙烯)-聚(丙烯酸-丙烯酰胺-甲基丙烯酸乙酯)-聚(偏二氟乙烯-六氟丙烯)中的一种或多种时，能够降低膜片电阻，提高粘结力，并降低电池的直流阻抗增长率。从实施例43与对比例1-2、7的对比可见，嵌段共聚物为聚偏二氟乙烯-聚丙烯酸-聚偏二氟乙烯三嵌段共聚物时，能够降低膜片电阻，提高粘结力，并降低电池的直流阻抗增长率，提高电池的循环容量保持率。From the comparison between Examples 25-31 and Examples 40-45 and Comparative Example 1, it can be seen that the block copolymer is a triblock copolymer of polyvinylidene fluoride-poly(acrylic acid-acrylamide-ethyl methacrylate)-polyvinylidene fluoride, polyvinyl fluoride-poly(acrylic acid-acrylamide-ethyl methacrylate)- One or more of the following: polyvinyl fluoride triblock copolymer, polytetrafluoroethylene-poly(acrylic acid-acrylamide-ethyl methacrylate)-polytetrafluoroethylene triblock copolymer, poly(vinylidene fluoride-hexafluoropropylene)-poly(acrylic acid-acrylamide-ethyl methacrylate)-poly(vinylidene fluoride-hexafluoropropylene) triblock copolymer, polyvinylidene fluoride-polyacrylic acid-polyvinylidene fluoride triblock copolymer, polyvinylidene fluoride-poly(acrylic acid-acrylamide)-polyvinylidene fluoride triblock copolymer, and polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylamide)-polyvinylidene fluoride triblock copolymer can effectively slow down the gelation of the slurry, improve the stability of the slurry, improve the flexibility of the pole piece, improve the bonding force, reduce the membrane resistance, and reduce the DC impedance growth rate of the battery. From the comparison of Examples 25-31 with Comparative Examples 1, 5 and 6, it can be seen that when the block copolymer is a triblock copolymer of polyvinylidene fluoride-poly(acrylic acid-acrylamide-ethyl methacrylate)-polyvinylidene fluoride, the gelation phenomenon of the slurry can be effectively slowed down, the stability of the slurry can be improved, the flexibility of the pole piece can be improved, the bonding force can be improved, and the DC impedance growth rate of the battery can be reduced, and the cycle capacity retention rate of the battery can be improved. From the comparison of Examples 40-42 with Comparative Example 5, it can be seen that when the block copolymer is a triblock copolymer of polyvinyl fluoride-poly(acrylic acid-acrylamide-ethyl methacrylate)-polyvinyl fluoride, polytetrafluoroethylene-poly(acrylic acid-acrylamide-ethyl methacrylate)-polytetrafluoroethylene, poly(vinylidene fluoride-hexafluoropropylene)-poly(acrylic acid-acrylamide-ethyl methacrylate)-poly(vinylidene fluoride-hexafluoropropylene), it can reduce the membrane resistance, improve the bonding force, and reduce the DC impedance growth rate of the battery. From the comparison between Example 43 and Comparative Examples 1-2 and 7, it can be seen that when the block copolymer is a triblock copolymer of polyvinylidene fluoride-polyacrylic acid-polyvinylidene fluoride, it can reduce the membrane resistance, improve the adhesion, reduce the DC impedance growth rate of the battery, and improve the battery's cycle capacity retention rate.
从实施例1-7、25-31和12-15、36-39与对比例6的对比可见，粘结剂的质量分数为0.1％-3％时，基于所述正极活性物质的总质量计，能够显著减缓浆料的凝胶现象，提高浆料稳定性，提高极片的柔性，并提高电池的循环容量保持率。从实施例1-7、25-31和14-15、38-39与对比例6的对比可见，粘结剂的质量分数为1％-3％，基于所述正极活性物质的总质量计，能够显著减缓浆料的凝胶现象，提高浆料稳 定性，提高极片的柔性，提高粘结力，降低膜片电阻，降低电池的直流阻抗增长率，并提高电池的循环容量保持率。From the comparison between Examples 1-7, 25-31 and 12-15, 36-39 and Comparative Example 6, it can be seen that when the mass fraction of the binder is 0.1%-3%, based on the total mass of the positive electrode active material, the gelation phenomenon of the slurry can be significantly slowed down, the slurry stability can be improved, the flexibility of the pole piece can be improved, and the cycle capacity retention rate of the battery can be improved. From the comparison between Examples 1-7, 25-31 and 14-15, 38-39 and Comparative Example 6, it can be seen that when the mass fraction of the binder is 1%-3%, based on the total mass of the positive electrode active material, the gelation phenomenon of the slurry can be significantly slowed down, the slurry stability can be improved, the flexibility of the pole piece can be improved, and the cycle capacity retention rate of the battery can be improved. Qualitative, improve the flexibility of the electrode, improve the bonding force, reduce the membrane resistance, reduce the DC impedance growth rate of the battery, and improve the cycle capacity retention rate of the battery.
需要说明的是，本申请不限定于上述实施方式。上述实施方式仅为示例，在本申请的技术方案范围内具有与技术思想实质相同的构成、发挥相同作用效果的实施方式均包含在本申请的技术范围内。此外，在不脱离本申请主旨的范围内，对实施方式施加本领域技术人员能够想到的各种变形、将实施方式中的一部分构成要素加以组合而构筑的其它方式也包含在本申请的范围内。 It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims (29)

  1. 一种BAB型嵌段共聚物，其特征在于，包含A-嵌段和B-嵌段，所述A-嵌段含有衍生自式I所示单体的结构单元，所述B-嵌段含有衍生自式II所示单体的结构单元；A BAB type block copolymer, characterized in that it comprises an A-block and a B-block, wherein the A-block contains a structural unit derived from a monomer represented by formula I, and the B-block contains a structural unit derived from a monomer represented by formula II;
    或者所述A-嵌段含有衍生自式II所示单体的结构单元，所述B-嵌段含有衍生自I所示单体的结构单元，
    Alternatively, the A-block contains structural units derived from the monomers of formula II, and the B-block contains structural units derived from the monomers of formula I,
    其中R1、R2、R3各自独立地选自氢、氟、至少含有一个氟原子的C1-3烷基中的一种或多种，R4、R5、R6各自独立地选自氢、取代或未取代的C1-5烷基。R 1 , R 2 , and R 3 are each independently selected from one or more of hydrogen, fluorine, and C 1-3 alkyl containing at least one fluorine atom; and R 4 , R 5 , and R 6 are each independently selected from hydrogen, and substituted or unsubstituted C 1-5 alkyl.
  2. 根据权利要求1所述的BAB型嵌段共聚物，其特征在于，所述B-嵌段还含有衍生自式III所示单体的结构单元；The BAB type block copolymer according to claim 1, characterized in that the B-block further contains a structural unit derived from a monomer represented by formula III;
    或者所述A-嵌段还包含衍生自式III所示单体的结构单元，
    Alternatively, the A-block further comprises a structural unit derived from a monomer of formula III,
    其中R7、R8、R9各自独立地选自氢、取代或未取代的C1-5烷基，R10选自酯基、氰基、酰胺基中的一种。R 7 , R 8 and R 9 are each independently selected from hydrogen, substituted or unsubstituted C 1-5 alkyl, and R 10 is selected from one of ester group, cyano group and amide group.
  3. 根据权利要求1或2所述的BAB型嵌段共聚物，其特征在于，基于所述BAB型嵌段共聚物中所有结构单元的总摩尔数计，所述衍生自式I所示单体的结构单元的摩尔含量为30％-70％，可选为 40％-60％。The BAB-type block copolymer according to claim 1 or 2, characterized in that the molar content of the structural unit derived from the monomer represented by formula I is 30%-70% based on the total molar number of all structural units in the BAB-type block copolymer, which can be optionally 40%-60%.
  4. 根据权利要求1至3中任一项所述的BAB型嵌段共聚物，其特征在于，所述BAB型嵌段共聚物的重均分子量为40万-200万，可选为120万-200万，更可选为120万-150万。The BAB type block copolymer according to any one of claims 1 to 3, characterized in that the weight average molecular weight of the BAB type block copolymer is 400,000-2 million, optionally 1.2 million-2 million, and more optionally 1.2 million-1.5 million.
  5. 根据权利要求1至4中任一项所述的BAB型嵌段共聚物，其特征在于，所述BAB型嵌段共聚物中，所述A-嵌段的重均分子量为20万-105万。The BAB type block copolymer according to any one of claims 1 to 4, characterized in that in the BAB type block copolymer, the weight average molecular weight of the A-block is 200,000-1,050,000.
  6. 根据权利要求1至5中任一项所述的BAB型嵌段共聚物，其特征在于，所述BAB型嵌段共聚物中，每个B-嵌段的重均分子量为10万-50万。The BAB type block copolymer according to any one of claims 1 to 5, characterized in that in the BAB type block copolymer, the weight average molecular weight of each B-block is 100,000 to 500,000.
  7. 根据权利要求1至6中任一项所述的BAB型嵌段共聚物，其特征在于，所述式I所示的单体选自偏氟乙烯、四氟乙烯、氟乙烯、六氟丙烯中的一种或多种。The BAB type block copolymer according to any one of claims 1 to 6, characterized in that the monomer represented by formula I is selected from one or more of vinylidene fluoride, tetrafluoroethylene, vinyl fluoride, and hexafluoropropylene.
  8. 根据权利要求1至7中任一项所述的BAB型嵌段共聚物，其特征在于，所述式II所示单体选自丙烯酸、甲基丙烯酸、乙基丙烯酸中的一种或多种。The BAB type block copolymer according to any one of claims 1 to 7, characterized in that the monomer represented by formula II is selected from one or more of acrylic acid, methacrylic acid, and ethacrylic acid.
  9. 根据权利要求2至8中任一项所述的BAB型嵌段共聚物，其特征在于，所述式III所示单体选自丙烯酰胺、丙烯酸酯、丙烯腈中的一种或多种。The BAB type block copolymer according to any one of claims 2 to 8, characterized in that the monomer represented by formula III is selected from one or more of acrylamide, acrylate, and acrylonitrile.
  10. 根据权利要求1至9中任一项所述的BAB型嵌段共聚物，其特征在于，所述BAB型嵌段共聚物为聚丙烯酸-聚偏二氟乙烯-聚丙烯酸三嵌段共聚物、聚丙烯酸-聚氟乙烯-聚丙烯酸三嵌段共聚物、聚丙烯酸-聚四氟乙烯-聚丙烯酸三嵌段共聚物、聚(丙烯酸-丙烯酸酯)- 聚偏二氟乙烯-聚(丙烯酸-丙烯酸酯)三嵌段共聚物、聚(丙烯酸-丙烯酸酯)-聚氟乙烯-聚(丙烯酸-丙烯酸酯)三嵌段共聚物、聚(丙烯酸-丙烯酸酯)-聚四氟乙烯-聚(丙烯酸-丙烯酸酯)三嵌段共聚物、聚(丙烯酸-丙烯腈-丙烯酸酯)-聚偏二氟乙烯-聚(丙烯酸-丙烯腈-丙烯酸酯)三嵌段共聚物、聚(丙烯酸-丙烯腈-丙烯酸酯)-聚氟乙烯-聚(丙烯酸-丙烯腈-丙烯酸酯)三嵌段共聚物、聚(丙烯酸-丙烯腈-丙烯酸酯)-聚四氟乙烯-聚(丙烯酸-丙烯腈-丙烯酸酯)三嵌段共聚物、聚(丙烯酸-丙烯酰胺-丙烯酸酯)-聚偏二氟乙烯-聚(丙烯酸-丙烯酰胺-丙烯酸酯)三嵌段共聚物、聚(丙烯酸-丙烯酰胺-丙烯酸酯)-聚氟乙烯-聚(丙烯酸-丙烯酰胺-丙烯酸酯)三嵌段共聚物、聚(丙烯酸-丙烯酰胺-丙烯酸酯)-聚四氟乙烯-聚(丙烯酸-丙烯酰胺-丙烯酸酯)三嵌段共聚物、聚(丙烯酸-丙烯腈)-聚偏二氟乙烯-聚(丙烯酸-丙烯腈)三嵌段共聚物、聚(丙烯酸-丙烯腈-丙烯酰胺)-聚偏二氟乙烯-聚(丙烯酸-丙烯腈-丙烯酰胺)三嵌段共聚物、聚(丙烯酸-丙烯腈-丙烯酸酯)-聚偏二氟乙烯-聚(丙烯酸-丙烯腈-丙烯酸酯)三嵌段共聚物、聚(丙烯酸-丙烯酰胺)-聚偏二氟乙烯-聚(丙烯酸-丙烯酰胺)三嵌段共聚物、聚(丙烯酸-丙烯腈-丙烯酰胺)-聚偏二氟乙烯-聚(丙烯酸-丙烯腈-丙烯酰胺)三嵌段共聚物、聚(偏二氟乙烯-六氟丙烯)-聚(丙烯酸-丙烯酰胺-丙烯酸酯)-聚(偏二氟乙烯-六氟丙烯)三嵌段共聚物、聚氟乙烯-聚丙烯酸-聚氟乙烯、聚四氟乙烯-聚丙烯酸-聚四氟乙烯三嵌段共聚物、聚偏二氟乙烯-聚(丙烯酸-丙烯酸酯)-聚偏二氟乙烯三嵌段共聚物、聚氟乙烯-聚(丙烯酸-丙烯酸酯)-聚氟乙烯三嵌段共聚物、聚四氟乙烯-聚(丙烯酸-丙烯酸酯)-聚四氟乙烯三嵌段共聚物、聚偏二氟乙烯-聚(丙烯酸-丙烯腈-丙烯酸酯)-聚偏二氟乙烯三嵌段共聚物、聚氟乙烯-聚(丙烯酸-丙烯腈-丙烯酸酯)-聚氟乙烯三嵌段共聚物、聚四氟乙烯-聚(丙烯酸-丙烯腈-丙烯酸酯)-聚四氟乙烯三嵌段共聚物、聚偏二氟乙烯-聚(丙烯酸-丙烯酰胺-丙烯酸酯)-聚偏二氟乙烯三嵌段共聚物、聚氟乙烯-聚(丙烯酸-丙烯酰胺-丙烯酸酯)-聚氟乙烯三嵌段共聚物、聚四氟乙烯-聚(丙烯酸-丙烯酰胺-丙烯酸酯)-聚四氟乙烯三嵌段共聚物、聚偏二氟乙烯-聚(丙烯酸-丙烯腈)-聚偏二氟乙烯三嵌 段共聚物、聚偏二氟乙烯-聚(丙烯酸-丙烯腈-丙烯酰胺)-聚偏二氟乙烯三嵌段共聚物、聚偏二氟乙烯-聚(丙烯酸-丙烯腈-丙烯酸酯)-聚偏二氟乙烯三嵌段共聚物、聚偏二氟乙烯-聚(丙烯酸-丙烯酰胺)-聚偏二氟乙烯三嵌段共聚物、聚偏二氟乙烯-聚(丙烯酸-丙烯腈-丙烯酰胺)-聚偏二氟乙烯三嵌段共聚物、聚(偏二氟乙烯-六氟丙烯)-聚(丙烯酸-丙烯酰胺-丙烯酸酯)-聚(偏二氟乙烯-六氟丙烯)三嵌段共聚物中的一种或多种。The BAB type block copolymer according to any one of claims 1 to 9, characterized in that the BAB type block copolymer is a polyacrylic acid-polyvinylidene fluoride-polyacrylic acid triblock copolymer, a polyacrylic acid-polyvinyl fluoride-polyacrylic acid triblock copolymer, a polyacrylic acid-polytetrafluoroethylene-polyacrylic acid triblock copolymer, a poly(acrylic acid-acrylate)- Polyvinylidene fluoride-poly(acrylic acid-acrylic ester) triblock copolymer, poly(acrylic acid-acrylic ester)-polyvinyl fluoride-poly(acrylic acid-acrylic ester) triblock copolymer, poly(acrylic acid-acrylic ester)-polytetrafluoroethylene-poly(acrylic acid-acrylic ester) triblock copolymer, poly(acrylic acid-acrylonitrile-acrylate)-polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylate) triblock copolymer, poly(acrylic acid-acrylonitrile-acrylate)-polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylate) triblock copolymer, poly(acrylic acid-acrylonitrile-acrylate)-polyvinyl fluoride-poly(acrylic acid-acrylonitrile-acrylate) triblock copolymer, poly(acrylic acid-acrylonitrile-acrylate)-polytetrafluoroethylene-poly(acrylic acid-acrylonitrile-acrylate) triblock copolymer, poly(acrylic acid-acrylamide-acrylate)-poly Vinylidene fluoride-poly(acrylic acid-acrylamide-acrylate) triblock copolymer, poly(acrylic acid-acrylamide-acrylate)-polyvinyl fluoride-poly(acrylic acid-acrylamide-acrylate) triblock copolymer, poly(acrylic acid-acrylamide-acrylate)-polytetrafluoroethylene-poly(acrylic acid-acrylamide-acrylate) triblock copolymer, poly(acrylic acid-acrylonitrile)-polyvinylidene fluoride-poly(acrylic acid-acrylonitrile) triblock copolymer, poly(acrylic acid-acrylonitrile-acrylamide)-polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylamide) triblock copolymer, poly(acrylic acid-acrylonitrile-acrylate)-polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylate) triblock copolymer, poly(acrylic acid-acrylonitrile-acrylate)-polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylate) triblock copolymer, (Acrylic acid-acrylamide)-polyvinylidene fluoride-poly(acrylic acid-acrylamide) triblock copolymer, poly(acrylic acid-acrylonitrile-acrylamide)-polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylamide) triblock copolymer, poly(vinylidene fluoride-hexafluoropropylene)-poly(acrylic acid-acrylamide-acrylate)-poly(vinylidene fluoride-hexafluoropropylene) triblock copolymer, polyvinyl fluoride-polyacrylic acid-polyvinyl fluoride, polytetrafluoroethylene-polyacrylic acid-polytetrafluoroethylene triblock copolymer, polyvinylidene fluoride-poly(acrylic acid-acrylate)-polyvinylidene fluoride triblock copolymer, polyvinyl fluoride-poly(acrylic acid-acrylate)-polyvinylidene fluoride triblock copolymer, polytetrafluoroethylene-poly(acrylic acid-acrylate )-polytetrafluoroethylene triblock copolymer, polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylate)-polyvinylidene fluoride triblock copolymer, polyvinyl fluoride-poly(acrylic acid-acrylonitrile-acrylate)-polyvinyl fluoride triblock copolymer, polytetrafluoroethylene-poly(acrylic acid-acrylonitrile-acrylate)-polytetrafluoroethylene triblock copolymer, polyvinylidene fluoride-poly(acrylic acid-acrylamide-acrylate)-polyvinylidene fluoride triblock copolymer, polyvinylidene fluoride-poly(acrylic acid-acrylamide-acrylate)-polyvinylidene fluoride triblock copolymer, polytetrafluoroethylene-poly(acrylic acid-acrylamide-acrylate)-polyvinylidene fluoride triblock copolymer, polyvinylidene fluoride-poly(acrylic acid-acrylonitrile)-polyvinylidene fluoride triblock copolymer The invention can be selected from the group consisting of a polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylamide)-polyvinylidene fluoride triblock copolymer, a polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylate)-polyvinylidene fluoride triblock copolymer, a polyvinylidene fluoride-poly(acrylic acid-acrylamide)-polyvinylidene fluoride triblock copolymer, a polyvinylidene fluoride-poly(acrylic acid-acrylamide)-polyvinylidene fluoride triblock copolymer, a polyvinylidene fluoride-poly(acrylic acid-acrylonitrile-acrylamide)-polyvinylidene fluoride triblock copolymer, and a poly(vinylidene fluoride-hexafluoropropylene)-poly(acrylic acid-acrylamide-acrylate)-poly(vinylidene fluoride-hexafluoropropylene) triblock copolymer.
  11. 一种BAB型嵌段共聚物的制备方法，其特征在于，包括以下步骤：A method for preparing a BAB type block copolymer, characterized in that it comprises the following steps:
    制备A-嵌段：将至少一种式I所示的单体聚合制备A-嵌段，Preparation of A-block: polymerizing at least one monomer represented by formula I to prepare A-block,
    或者将单体单元聚合制备A-嵌段，所述单体单元包括至少一种式II所示的单体，
    Alternatively, the A-block is prepared by polymerizing monomer units, wherein the monomer units include at least one monomer represented by formula II,
    其中R1、R2、R3各自独立地选自氢、氟、至少含有一个氟原子的C1-3烷基中的一种或多种，R4、R5、R6各自独立地选自氢、取代或未取代的C1-5烷基；wherein R 1 , R 2 , and R 3 are each independently selected from one or more of hydrogen, fluorine, and C 1-3 alkyl containing at least one fluorine atom; and R 4 , R 5 , and R 6 are each independently selected from hydrogen, and substituted or unsubstituted C 1-5 alkyl;
    制备B-嵌段：将单体单元聚合制备B-嵌段，所述单体单元包括至少一种式II所示的单体，Preparation of B-block: polymerizing monomer units to prepare B-block, wherein the monomer units include at least one monomer represented by formula II,
    或者将至少一种式I所示的单体聚合制备B-嵌段；Alternatively, at least one monomer of formula I is polymerized to prepare a B-block;
    制备BAB型嵌段共聚物：将所述A-嵌段和所述B-嵌段接合制备BAB型嵌段共聚物，其中所述A-嵌段和所述B-嵌段含有不同的结构单元。Preparation of a BAB type block copolymer: The A-block and the B-block are joined to prepare a BAB type block copolymer, wherein the A-block and the B-block contain different structural units.
  12. 根据权利要求11所述的制备方法，其特征在于，所述单体单元还包括至少一种式III所示的单体，
    The preparation method according to claim 11, characterized in that the monomer unit further comprises at least one monomer represented by formula III,
    其中R7、R8、R9各自独立地选自氢、取代或未取代的C1-5烷基，R10选自酯基、氰基、酰胺基中的一种。R 7 , R 8 and R 9 are each independently selected from hydrogen, substituted or unsubstituted C 1-5 alkyl, and R 10 is selected from one of ester group, cyano group and amide group.
  13. 根据权利要求11或12所述的制备方法，其特征在于，所述制备B-嵌段的方法包括：The preparation method according to claim 11 or 12, characterized in that the method for preparing the B-block comprises:
    将至少一种式I所示的单体或所述单体单元、链转移剂、第一引发剂在60-80℃的反应温度下通过可逆加成-裂解链转移聚合，反应4.5-7小时，得到末端具有炔基或叠氮基团作为端基的所述B-嵌段。At least one monomer or monomer unit represented by formula I, a chain transfer agent, and a first initiator are subjected to reversible addition-fragmentation chain transfer polymerization at a reaction temperature of 60-80° C. for 4.5-7 hours to obtain the B-block having an alkynyl group or an azide group as an end group.
  14. 根据权利要求11至13中任一项所述的制备方法，其特征在于，所述制备A-嵌段的方法包括：The preparation method according to any one of claims 11 to 13, characterized in that the method for preparing the A-block comprises:
    将至少一种式I所示单体或所述单体单元、第二引发剂在80-95℃的反应温度下聚合反应2.5-5小时，对产物的端基进行取代反应，制备两端均具有叠氮基团或炔基作为端基的所述A-嵌段。At least one monomer represented by formula I or the monomer unit and a second initiator are polymerized at a reaction temperature of 80-95° C. for 2.5-5 hours, and the end groups of the product are substituted to prepare the A-block having azide groups or alkynyl groups as end groups at both ends.
  15. 根据权利要求11至14中任一项所述的制备方法，其特征在于，所述制备BAB型嵌段共聚物的方法包括：The preparation method according to any one of claims 11 to 14, characterized in that the method for preparing the BAB type block copolymer comprises:
    将两端均具有叠氮基团或炔基作为端基的所述A-嵌段与末端具有炔基或叠氮基团作为端基的所述B-嵌段混合，进行点击反应，制备BAB型嵌段共聚物，其中所述A-嵌段和所述B-嵌段的端基不同。The A-block having an azide group or an alkynyl group as an end group at both ends is mixed with the B-block having an alkynyl group or an azide group as an end group at the end, and a click reaction is performed to prepare a BAB type block copolymer, wherein the end groups of the A-block and the B-block are different.
  16. 根据权利要求13至15中任一项所述的制备方法，其特征在于，所述链转移剂为含末端炔基或叠氮基团的RAFT链转移剂。The preparation method according to any one of claims 13 to 15, characterized in that the chain transfer agent is a RAFT chain transfer agent containing a terminal alkynyl group or an azide group.
  17. 根据权利要求13至16中任一项所述的制备方法，其特征在于，所述第一引发剂包含偶氮引发剂。 The preparation method according to any one of claims 13 to 16, characterized in that the first initiator comprises an azo initiator.
  18. 根据权利要求13至16中任一项所述的制备方法，其特征在于，所述第一引发剂包含偶氮二异丁腈，偶氮二异庚腈的一种或两种。The preparation method according to any one of claims 13 to 16, characterized in that the first initiator comprises one or both of azobisisobutyronitrile and azobisisoheptanenitrile.
  19. 根据权利要求14至18中任一项所述的制备方法，其特征在于，所述第二引发剂包含对称型双官能度引发剂。The preparation method according to any one of claims 14 to 18, characterized in that the second initiator comprises a symmetrical bifunctional initiator.
  20. 根据权利要求14至18中任一项所述的制备方法，其特征在于，所述第二引发剂包含4-(氯甲基)过氧化苯甲酰。The preparation method according to any one of claims 14 to 18, characterized in that the second initiator comprises 4-(chloromethyl)benzoyl peroxide.
  21. 权利要求1至10中任一项所述的BAB型嵌段共聚物在二次电池中的应用。Use of the BAB type block copolymer according to any one of claims 1 to 10 in a secondary battery.
  22. 一种正极极片，包括正极集流体以及设置在正极集流体至少一个表面的正极膜层，所述正极膜层包括正极活性物质、导电剂和粘结剂，所述粘结剂为权利要求1至10中任一项所述的BAB型嵌段共聚物或权利要求11至20中任一项所述的制备方法制备的BAB型嵌段共聚物。A positive electrode sheet comprises a positive electrode current collector and a positive electrode film layer arranged on at least one surface of the positive electrode current collector, wherein the positive electrode film layer comprises a positive electrode active material, a conductive agent and a binder, wherein the binder is a BAB type block copolymer according to any one of claims 1 to 10 or a BAB type block copolymer prepared by the preparation method according to any one of claims 11 to 20.
  23. 根据权利要求22所述的正极极片，其特征在于，基于所述正极活性物质的总质量计，所述粘结剂的质量分数为0.1％-3％，可选为1％-3％。The positive electrode plate according to claim 22 is characterized in that, based on the total mass of the positive electrode active material, the mass fraction of the binder is 0.1%-3%, and can be optionally 1%-3%.
  24. 根据权利要求22或23所述的正极极片，其特征在于，所述正极膜层与所述正极集流体间单位长度的粘结力不小于8N/m，可选为不小于10N/m。The positive electrode plate according to claim 22 or 23 is characterized in that the bonding force per unit length between the positive electrode film layer and the positive electrode current collector is not less than 8 N/m, and can be optionally not less than 10 N/m.
  25. 根据权利要求22至24中任一项所述的正极极片，其特征在于，所述正极极片在经过不少于3次的弯折测试后，所述正极极片出 现透光现象。The positive electrode sheet according to any one of claims 22 to 24, characterized in that after the positive electrode sheet has been subjected to no less than 3 bending tests, the positive electrode sheet has Light transmission phenomenon occurs.
  26. 根据权利要求22至25中任一项所述的正极极片，其特征在于，所述正极极片的膜片电阻≤0.52Ω，可选为≤0.46Ω。The positive electrode plate according to any one of claims 22 to 25 is characterized in that the membrane resistance of the positive electrode plate is ≤0.52Ω, and can be optionally ≤0.46Ω.
  27. 一种二次电池，其特征在于，包括电极组件和电解液，所述电极组件包括隔离膜、负极极片和权利要求22至26中任一项所述的正极极片。A secondary battery, characterized in that it comprises an electrode assembly and an electrolyte, wherein the electrode assembly comprises a separator, a negative electrode sheet and the positive electrode sheet according to any one of claims 22 to 26.
  28. 根据权利要求27所述的二次电池，其特征在于，所述二次电池包括锂离子电池、钠离子电池、镁离子电池、钾离子电池中的至少一种。The secondary battery according to claim 27 is characterized in that the secondary battery includes at least one of a lithium ion battery, a sodium ion battery, a magnesium ion battery, and a potassium ion battery.
  29. 一种用电装置，其特征在于，包括权利要求27或28所述的二次电池。 An electrical device, characterized by comprising the secondary battery described in claim 27 or 28.
PCT/CN2023/101439 2022-09-30 2023-06-20 Bab-type block copolymer, preparation method, binder, positive pole piece, secondary battery, and electrical apparatus WO2024066507A1 (en)

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Publication number Priority date Publication date Assignee Title
JPH1145720A (en) * 1997-07-25 1999-02-16 Hitachi Maxell Ltd Lithium secondary battery
US20150057419A1 (en) * 2013-08-23 2015-02-26 University Of Connecticut Free radical and controlled radical polymerization processes using azide radical initiators
CN104610518A (en) * 2015-01-19 2015-05-13 巨化集团技术中心 Preparation method of PVDF-PAA (polyvinylidene fluoride-polyacrylic acid) block copolymer
CN108417836A (en) * 2018-01-31 2018-08-17 闽南师范大学 A kind of binders for electrodes of new type lithium ion battery and preparation method thereof
CN110156999A (en) * 2019-05-28 2019-08-23 济南大学 A kind of preparation method of click chemistry synthesizing amphipathic fluorine-containing block copolymer
CN115286805A (en) * 2022-09-30 2022-11-04 宁德时代新能源科技股份有限公司 BAB type block copolymer, preparation method, binder, positive pole piece, secondary battery and electric device

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH1145720A (en) * 1997-07-25 1999-02-16 Hitachi Maxell Ltd Lithium secondary battery
US20150057419A1 (en) * 2013-08-23 2015-02-26 University Of Connecticut Free radical and controlled radical polymerization processes using azide radical initiators
CN104610518A (en) * 2015-01-19 2015-05-13 巨化集团技术中心 Preparation method of PVDF-PAA (polyvinylidene fluoride-polyacrylic acid) block copolymer
CN108417836A (en) * 2018-01-31 2018-08-17 闽南师范大学 A kind of binders for electrodes of new type lithium ion battery and preparation method thereof
CN110156999A (en) * 2019-05-28 2019-08-23 济南大学 A kind of preparation method of click chemistry synthesizing amphipathic fluorine-containing block copolymer
CN115286805A (en) * 2022-09-30 2022-11-04 宁德时代新能源科技股份有限公司 BAB type block copolymer, preparation method, binder, positive pole piece, secondary battery and electric device

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