WO2024000167A1 - Polymère et son procédé de préparation, plaque d'électrode, batterie secondaire, module de batterie, bloc-batterie et dispositif électrique - Google Patents

Polymère et son procédé de préparation, plaque d'électrode, batterie secondaire, module de batterie, bloc-batterie et dispositif électrique Download PDF

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WO2024000167A1
WO2024000167A1 PCT/CN2022/101939 CN2022101939W WO2024000167A1 WO 2024000167 A1 WO2024000167 A1 WO 2024000167A1 CN 2022101939 W CN2022101939 W CN 2022101939W WO 2024000167 A1 WO2024000167 A1 WO 2024000167A1
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polymer
structural unit
lithium
alkyl
optionally
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PCT/CN2022/101939
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Chinese (zh)
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张玉玺
艾少华
周鑫
陈煜�
曾琦
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宁德时代新能源科技股份有限公司
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Priority to CN202280060003.7A priority Critical patent/CN117941106A/zh
Priority to PCT/CN2022/101939 priority patent/WO2024000167A1/fr
Publication of WO2024000167A1 publication Critical patent/WO2024000167A1/fr

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    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers

Definitions

  • the present application relates to the field of battery technology, and in particular to a polymer and its preparation method, pole pieces, secondary batteries, battery modules, battery packs and electrical devices.
  • lithium-ion batteries are widely used in energy storage power systems such as hydraulic, thermal, wind and solar power stations, as well as power tools, electric bicycles, electric motorcycles, electric Automobiles, military equipment, aerospace and other fields. Due to the great development of lithium-ion batteries, higher requirements have been put forward for their energy density, cycle performance and safety performance. In addition, the requirements for the standby time or cruising range of products such as portable electronic products and new energy vehicles are getting higher and higher. Therefore, higher requirements are placed on the energy density of lithium-ion batteries.
  • the negative active material easily reacts with the electrolyte, causing the loss of active material, thereby reducing the energy density of the lithium-ion battery. Therefore, the energy density of existing lithium-ion batteries still needs to be improved.
  • This application was made in view of the above-mentioned issues, and provides a polymer and its preparation method, pole pieces, secondary batteries, battery modules, battery packs and electrical devices to solve the problem of low energy density of lithium-ion batteries. The problem.
  • the first aspect of the present application provides a polymer.
  • the polymer includes a first structural unit, a second structural unit and a third structural unit; wherein the first structural unit has the structural formula shown in formula I,
  • R 1 and R 2 are independently selected from H or C 1-18 alkyl, optionally H or C 1-6 alkyl;
  • the second structural unit has the structural formula shown in Formula II,
  • R 3 , R 4 , R 5 , R 6 and R 7 are independently selected from one of H, C 1 to 18 alkyl, C 1 to 18 alkoxy or lithium oxy, and R 3 , R 4. At least one of R 5 , R 6 and R 7 is lithium oxy group, optionally H, C 1 to 6 alkyl group, C 1 to 6 alkoxy group or lithium oxy group, R 8 is selected from H or C 6 ⁇ 18 aryl group, optionally H or phenyl;
  • the third structural unit has the structural formula shown in formula III,
  • R a and R b are selected from Or one of CN, R 9 and R 10 are independently selected from H or C 1-18 alkyl, optionally H or C 1-6 alkyl.
  • a polymer containing a lithium oxygen functional group monomer on the benzene ring is used as a binder in a lithium ion battery.
  • the lithium oxygen functional group on the benzene ring of the polymer It is oxidized into benzoquinone and releases lithium ions.
  • the released lithium ions participate in the formation of SEI film on the surface of the negative electrode during the first charge, thereby reducing the consumption of reversible lithium of the positive active material, improving the reversible capacity of the positive active material, and further increasing the lithium Ion battery energy density.
  • the phenol oxygen contained in the lithium oxygen group on the benzene ring in the polymer can be oxidized into benzoquinone and release lithium ions even at a lower operating voltage than the lithium-ion battery (usually 4.2V), thereby making the battery It can maintain high energy density during charging and discharging.
  • R 8 has the structural formula shown in formula IV,
  • R 11 , R 12 , R 13 , R 14 and R 15 are independently selected from one of H, C 1 to 18 alkyl, C 1 to 18 alkoxy or lithium oxy, and R 11 , R 12. At least one of R 13 , R 14 and R 15 is a lithium oxygen group, optionally one of H, C 1 to 6 alkyl groups, C 1 to 6 alkoxy groups or lithium oxygen groups, # represents connection Location.
  • the second structural unit has two benzene rings, and both benzene rings have lithium oxygen functional groups, which increases the ability of the polymer to provide lithium, thereby improving the lithium supplement for lithium-ion batteries. quantity.
  • the second structural unit is selected from
  • Chemical activity enabling more favorable release of lithium ions from polymers.
  • the first structural unit is derived from an acrylate monomer, and the acrylate monomer is selected from the group consisting of acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, and n-butyl acrylate. , isobutyl acrylate, tert-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate or One or more of the C 9 to C 16 alkyl methacrylates.
  • these specific alternative examples of acrylate monomers can provide good polymer processing and bonding properties.
  • the third structural unit is derived from an acrylamide monomer or an acrylonitrile monomer; the acrylamide monomer is selected from acrylamide, N-isopropylacrylamide, N- One or more of (3-dimethylaminopropyl)methacrylamide or N,N'-methylenebisacrylamide.
  • these specific optional acrylate monomer examples can provide good polymer processing properties and solubility properties, thereby allowing the polymer to have better performance with the cathode active material and the optional conductive agent. compatibility.
  • these specific examples of optional acrylic ester monomers have good affinity with the electrolyte and are conducive to the wetting of the electrolyte.
  • the molar ratio of the first structural unit, the second structural unit and the third structural unit of the polymer is 1:(0.02 ⁇ 3):(0.2 ⁇ 5).
  • the polymer is a copolymer including a first structural unit, a second structural unit and a third structural unit, and the molar ratio of the first structural unit, the second structural unit and the third structural unit is within an appropriate range.
  • the polymer has a structural formula represented by Formula V,
  • a is selected from 0 to 5000
  • b and c are independently selected from 500 to 50000
  • d is selected from 10 to 5000.
  • the lithium oxygen group on the benzene ring in the polymer is more active, and the lithium oxygen group on the benzene ring in the polymer can be removed by a voltage below 3.6V. Oxidized to benzoquinone, lithium ions are released, thereby maintaining a high energy density during rapid charge and discharge.
  • the polymer has a weight average molecular weight of 20,000 to 2,000,000, optionally 100,000 to 1,000,000.
  • the weight average molecular weight of the polymer if the weight average molecular weight of the polymer is too low, the adhesive force of the polymer to the active material will be insufficient; if the weight average molecular weight of the polymer is too high, the polymer, cathode active material and optional The processing performance of the positive electrode film layer formed by the conductive agent will deteriorate.
  • the second aspect of the application also provides a method for preparing a polymer, including:
  • the monomer corresponding to the first structural unit has the structural formula shown in formula I-a,
  • R 1 and R 2 are independently selected from H or C 1-18 alkyl, optionally H or C 1-6 alkyl;
  • the monomer corresponding to the second structural unit has the structural formula shown in formula II-a,
  • R 3 , R 4 , R 5 , R 6 and R 7 are independently selected from one of H, C 1 to 18 alkyl, C 1 to 18 alkoxy or lithium oxy, and R 3 , R 4. At least one of R 5 , R 6 and R 7 is lithium oxy group, optionally H, C 1 to 6 alkyl group, C 1 to 6 alkoxy group or lithium oxy group, R 8 is selected from H or C 6 ⁇ 18 aryl group, optionally H or phenyl;
  • the monomer corresponding to the third structural unit has the structural formula shown in formula III-a,
  • R a and R b are selected from Or one of CN, R 9 and R 10 are independently selected from H or C 1-18 alkyl, optionally H or C 1-6 alkyl.
  • each raw material is first mixed with an emulsifier, an initiator and a dispersion medium to form an emulsion, and then a polymerization reaction is initiated at a certain temperature to prepare a polymer.
  • Its preparation process is simple, easy to control, and has high manufacturability.
  • the total mass of the monomer corresponding to the first structural unit, the monomer corresponding to the second structural unit and the monomer corresponding to the third structural unit, emulsifier, initiator and dispersion is 100:(0.6 ⁇ 10):(0.6 ⁇ 2):(100 ⁇ 300), optionally 100:(2 ⁇ 3):(0.8 ⁇ 1.2):(110 ⁇ 130).
  • the molecular weight of the prepared polymer is adjusted, and the prepared polymer can effectively exert the effect of a binder.
  • the heating temperature is greater than 80°C; the heating time is 2h to 5h.
  • polymerization occurs by reacting derivatized radicals through heat treatment to obtain a polymer.
  • the heating temperature and heating time will directly affect the molecular weight of the polymer. Such settings can ensure that the polymer has an appropriate molecular weight.
  • a third aspect of the present application provides a pole piece, including the polymer of the first aspect of the present application or a polymer prepared by the preparation method of the second aspect of the present application.
  • a fourth aspect of the present application provides a secondary battery, including the pole piece of the third aspect.
  • a fifth aspect of the present application provides a battery module including the secondary battery of the fourth aspect of the present application.
  • a sixth aspect of the present application provides a battery pack, including the battery module of the fifth aspect of the present application.
  • a seventh aspect of the present application provides an electrical device, including at least one selected from the secondary battery of the fourth aspect of the present application, the battery module of the fifth aspect of the present application, or the battery pack of the sixth aspect of the present application. kind.
  • FIG. 1 is a schematic diagram of a secondary battery according to an embodiment of the present application.
  • FIG. 2 is an exploded view of the secondary battery according to the embodiment of the present application shown in FIG. 1 .
  • FIG. 3 is a schematic diagram of a battery module according to an embodiment of the present application.
  • Figure 4 is a schematic diagram of a battery pack according to an embodiment of the present application.
  • FIG. 5 is an exploded view of the battery pack according to an embodiment of the present application shown in FIG. 4 .
  • FIG. 6 is a schematic diagram of a power consumption device using a secondary battery as a power source according to an embodiment of the present application. .
  • Ranges disclosed herein are defined in terms of lower and upper limits. A given range is defined by selecting a lower limit and an upper limit that define the boundaries of the particular range. Ranges defined in this manner may be inclusive or exclusive of the endpoints, and may be arbitrarily combined, that is, any lower limit may be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a particular parameter, understand that ranges of 60-110 and 80-120 are also expected. Furthermore, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2- 3, 2-4 and 2-5.
  • the numerical range “a-b” represents an abbreviated representation of any combination of real numbers between a and b, where a and b are both real numbers.
  • the numerical range “0-5" means that all real numbers between "0-5" have been listed in this article, and "0-5" is just an abbreviation of these numerical combinations.
  • a certain parameter is an integer ⁇ 2
  • 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.
  • step (c) means that step (c) may be added to the method in any order.
  • the method may include steps (a), (b) and (c). , may also include steps (a), (c) and (b), may also include steps (c), (a) and (b), etc.
  • condition "A or B” is satisfied by any of the following conditions: 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).
  • Lithium-ion batteries have many advantages such as long cycle life, high energy density, and green environmental protection. They have been rapidly developed in fields such as portable electronic products, new energy vehicles, smart grids, and distributed energy storage. In addition, the requirements for the standby time or cruising range of products such as portable electronic products and new energy vehicles are getting higher and higher. Therefore, higher requirements are placed on the energy density of lithium-ion batteries.
  • graphite-based negative electrode active materials react with the electrolyte during the first charging of the lithium-ion battery and form a solid electrolyte interface (SEI) film on the surface of the negative electrode to prevent further side reactions between the electrolyte and the negative electrode. In this case, the first charge Coulombic efficiency of the negative active material is low, usually less than 93%.
  • the first charge Coulombic efficiency of positive active materials can reach more than 98%.
  • the Coulombic efficiency of the positive active material is much higher than that of the negative active material.
  • the lithium ions released from the positive active material are used to form the SEI film, which is consumed by the negative electrode surface and cannot be embedded in the negative active material.
  • the reversible capacity is formed within the cathode active material, so that the positive active material cannot exert its maximum reversible capacity, resulting in a low energy density of the lithium-ion battery. Therefore, how to increase the maximum reversible capacity is an effective way to increase the energy density of lithium-ion batteries.
  • the applicant improved the binder and realized a polymer (binder) that can be used as another active lithium source by introducing specific structural units.
  • Such an additional lithium source can Effectively replenishes the irreversible loss of active lithium capacity due to the first charge and discharge.
  • alkyl refers to a saturated hydrocarbon group, including both straight-chain and branched-chain structures.
  • C 1 to 18 alkyl represents an alkyl group with 1 to 18 carbon atoms, examples of which include but are not limited to methyl, ethyl, propyl (such as n-propyl, isopropyl), butyl (such as n-butyl , isobutyl, sec-butyl, tert-butyl), pentyl (such as n-pentyl, isopentyl, neopentyl), etc.
  • alkoxy refers to -OR, where R is alkyl.
  • alkoxy groups include, but are not limited to, methoxy (CH 3 O-), ethoxy (C 2 H 5 O-), propoxy (C 3 H 7 O-), and the like.
  • lithium oxy refers to -OLi.
  • aryl refers to a closed aromatic ring or ring system.
  • C 6-18 aryl means an aryl group containing 6-18 ring carbon atoms.
  • Examples of C 6 to 18 aryl groups include, but are not limited to, phenyl, naphthyl, fluorenyl, indenyl, anthracenyl, phenanthrenyl, pyrenyl and similar aryl groups.
  • a first aspect of the application provides a polymer including a first structural unit, a second structural unit and a third structural unit.
  • the first structural unit in the polymer has the structural formula shown in Formula I,
  • R 1 and R 2 are independently selected from H or C 1 to 18 alkyl.
  • the second structural unit in the polymer has the structural formula shown in formula II,
  • R 3 , R 4 , R 5 , R 6 and R 7 are independently selected from one of H, C 1 to 18 alkyl, C 1 to 18 alkoxy or lithium oxy, and R 3 , R 4. At least one of R 5 , R 6 and R 7 is lithium oxy group, optionally H, C 1 to 6 alkyl group, C 1 to 6 alkoxy group or lithium oxy group, R 8 is selected from H or C 6 ⁇ 18 aryl group.
  • the third structural unit in the polymer has the structural formula shown in formula III,
  • R a and R b are selected from Or one of CN, R 9 and R 10 are independently selected from H or C 1 to 18 alkyl.
  • the polymer may be used as a binder in, for example, an active material film layer of a lithium-ion battery electrode plate to firmly bond the positive active material and optional conductive agent to the positive current collector.
  • the second structural unit of the polymer has a structural formula shown in formula II,
  • R 3 , R 4 , R 5 , R 6 and R 7 are independently selected from one of H, C 1 to 18 alkyl, C 1 to 18 alkoxy or lithium oxy, and R 3 , R 4. At least one of R 5 , R 6 and R 7 is a lithium oxygen group, and R 8 is selected from H or C 6 to 18 aryl groups. That is to say, the benzene ring in the second structural unit of the polymer of the present application contains a lithium oxygen functional group.
  • this polymer when used as a binder, for example, in the electrode film layer of a lithium-ion battery, during the first charging process of the lithium-ion battery, the lithium oxygen functional group on the benzene ring is oxidized to benzoquinone and releases lithium ions.
  • the released lithium ions can replenish lithium.
  • the released lithium ions can participate in the formation of the solid electrolyte interface (SEI) film on the surface of the negative electrode, thereby reducing the consumption of reversible lithium in the positive electrode active material, improving the reversible capacity of the positive electrode active material, and further increasing the energy density of lithium-ion batteries.
  • SEI solid electrolyte interface
  • the phenol oxygen of the second structural unit can be oxidized to form benzoquinone even under lower voltage conditions, releasing lithium ions. Therefore, when the polymer of the present application is used as a binder for the active material film layer of a lithium-ion battery pole piece, lithium ions can be reliably released during the first charging process of the battery.
  • R 3 , R 4 , R 5 , R 6 and R 7 are independently selected from one of H, C 1 to 6 alkyl, C 1 to 6 alkoxy or lithium oxy, and At least one of R 3 , R 4 , R 5 , R 6 and R 7 is a lithium oxy group.
  • two of R 3 , R 4 , R 5 , R 6 and R 7 are lithium oxygen groups, and the others are selected from H, C 1 to 6 alkyl groups, and C 1 to 6 alkoxy groups.
  • one of R 3 , R 4 , R 5 , R 6 and R 7 is a lithium oxygen group, and the others are selected from H, C 1 to 6 alkyl groups, and C 1 to 6 alkoxy groups.
  • two of R 3 , R 4 , R 5 , R 6 and R 7 are lithium oxygen groups and are located at positions adjacent to each other on the benzene ring, and the others are selected from H.
  • the first structural unit included in the polymer has the structural formula shown in Formula I,
  • R 1 and R 2 are independently selected from H or C 1 to 18 alkyl.
  • the first structural unit is derived from an acrylic ester monomer, and therefore, the first structural unit enables the polymer to have the properties of an acrylic ester polymer.
  • the first structural unit can give the polymer a certain flexibility and cohesive strength, and can ensure the adhesiveness of the polymer, so that the polymer can be used as a binder to combine the positive active material and the optional conductive agent. Firmly bonded together and firmly bonded to the positive electrode current collector.
  • R 1 is selected from H or C 1-6 alkyl. Alternatively, R 1 is selected from H or C 2-4 alkyl. More optionally, R1 is H.
  • R 2 is selected from H or C 1-6 alkyl. Alternatively, R 2 is selected from H or C 2-4 alkyl. More optionally, R 2 is selected from C 2 to 4 alkyl.
  • the third structural unit included in the polymer has the structural formula shown in Formula III,
  • R a and R b are selected from Or one of CN, R 9 and R 10 are independently selected from H or C 1 to 18 alkyl.
  • the third structural unit is derived from an acrylamide monomer or acrylonitrile. Therefore, the third structural unit enables the polymer to have the properties of an acrylamide polymer or an acrylonitrile polymer.
  • the third structural unit can adjust the polarity and solubility parameters of the polymer so that the polymer can be dissolved in a suitable organic solvent, thereby making the polymer have excellent process performance as a binder and making it easier to realize cathode active materials and reusable materials. Uniform dispersion of selected conductive agent in polymer binder.
  • the first Coulombic efficiency of the positive active material of a lithium-ion battery can reach more than 98%. For example, taking the first Coulombic efficiency of 98% as an example, if the positive active material oxidizes and releases 100M lithium ions during the first charge, it can embed 98M lithium ions during discharge. The first Coulombic efficiency of lithium-ion battery negative active materials usually does not exceed 93%.
  • the first Coulombic efficiency of 93% if the positive active material takes out 100M lithium ions during the first charge, only 93M lithium ions are embedded in the negative active material. . That is to say, when the lithium-ion battery is discharged, the effective reversible capacity formed from the inside of the negative electrode active material is only 93M, and the remaining 7M lithium ions are used to form an SEI film on the surface of the negative electrode and are consumed, forming an ineffective irreversible capacity. It can be seen that because the first Coulombic efficiency of the negative active material is lower than that of the positive active material, the lithium-ion battery can release 93M electron power instead of 98M electron power when discharging.
  • the benzene ring in the polymer of the present application contains lithium oxygen functional groups, and the polymer can be used as a binder for, for example, the active material film layer of the positive electrode sheet of a lithium-ion battery, that is, the positive electrode film layer.
  • the binder in the positive electrode film layer is oxidized to release lithium ions, and an SEI film is formed on the surface of the negative electrode, thus making up for the reversible loss of lithium in the positive electrode active material and increasing the discharge capacity of the positive electrode active material ( reversible lithium ion).
  • the positive active material is oxidized to release 100M lithium ions during the first charge, and the binder is oxidized to release 5M lithium ions, and the first Coulombic efficiency of the positive active material is 98%, then a total of 105M lithium ions can be released from the positive electrode during charging, and 105M lithium ions can be released from the positive electrode during discharge.
  • the positive active material can embed 98M lithium ions.
  • a polymer containing a lithium oxygen functional group monomer on the benzene ring is used as a binder in a lithium ion battery.
  • the lithium oxygen functional group on the benzene ring of the polymer It is oxidized into benzoquinone and releases lithium ions.
  • the released lithium ions participate in the formation of SEI film on the surface of the negative electrode during the first charge, thereby reducing the consumption of reversible lithium of the positive active material, improving the reversible capacity of the positive active material, and further increasing the lithium Ion battery energy density.
  • the phenol oxygen contained in the lithium oxygen group on the benzene ring in the polymer can be oxidized into benzoquinone and release lithium ions even at a lower operating voltage than the lithium-ion battery (usually 4.2V), thereby making the battery It can maintain high energy density during charging and discharging.
  • R 8 is selected from H or C 6 to 10 aryl groups. More optionally, R 8 is phenyl.
  • R 8 has the structural formula shown in Formula IV,
  • R 11 , R 12 , R 13 , R 14 and R 15 are independently selected from one of H, C 1 to 18 alkyl, C 1 to 18 alkoxy or lithium oxy, and R 11 , R At least one of 12 , R 13 , R 14 and R 15 is a lithium oxy group, and # represents the connection position.
  • R 11 , R 12 , R 13 , R 14 and R 15 are independently selected from one of H, C 1 to 6 alkyl, C 1 to 6 alkoxy or lithium oxygen, And at least one of R 11 , R 12 , R 13 , R 14 and R 15 is a lithium oxy group.
  • two of R 11 , R 12 , R 13 , R 14 and R 15 are lithium oxygen groups, and the others are selected from H, C 1 to 6 alkyl groups, and C 1 to 6 alkoxy groups.
  • one of R 11 , R 12 , R 13 , R 14 and R 15 is a lithium oxygen group, and the others are selected from H, C 1 to 6 alkyl groups, and C 1 to 6 alkoxy groups.
  • two of R 11 , R 12 , R 13 , R 14 and R 15 are lithium oxygen groups and are located at positions adjacent to each other on the benzene ring, and the others are selected from H.
  • the second structural unit has two benzene rings, and both benzene rings contain lithium oxygen groups, thereby increasing the polymer's ability to provide lithium, thereby increasing the amount of lithium supplement for the lithium-ion battery.
  • precise and efficient lithium replenishment for lithium-ion batteries can be achieved by controlling the molar amount of the second structural unit in the polymer.
  • the second structural unit is selected from one or more of the following:
  • the benzene rings in the second structural unit each contain two lithium oxy groups, and the two lithium oxy groups are located adjacent to each other on the benzene ring, thereby more effectively increasing the electrochemical activity of the polymer. Lithium ions can be released from the polymer more favorably.
  • the first structural unit is derived from an acrylate monomer selected from acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, acrylic acid Tert-butyl ester, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate or methacrylic acid C 9 ⁇ C One or more of the 16 alkyl esters.
  • an acrylate monomer selected from acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, acrylic acid Tert-butyl ester, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, 2-e
  • the acrylate monomer is selected from one or more of acrylic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate or tert-butyl acrylate.
  • the acrylate monomer is selected from one or more of methyl acrylate, ethyl acrylate, n-butyl acrylate or isobutyl acrylate.
  • the third structural unit is derived from an acrylamide-based monomer or an acrylonitrile-based monomer.
  • the acrylamide monomer is selected from one of acrylamide, N-isopropylacrylamide, N-(3-dimethylaminopropyl)methacrylamide or N,N'-methylenebisacrylamide, or Several kinds.
  • the acrylonitrile monomer is acrylonitrile.
  • these specific optional monomer examples of the third structural unit can give the polymer good process performance and suitable solubility properties, so that the polymer has better performance with the cathode active material and the optional conductive agent. compatibility. Moreover, these specific optional monomer examples have good affinity with the electrolyte, which is beneficial to the electrolyte soaking into the polymer.
  • the molar ratio of the first structural unit, the second structural unit and the third structural unit of the polymer is 1:(0.02 ⁇ 3):(0.2 ⁇ 5).
  • the first structural unit, the second structural unit and the third structural unit are connected in a random copolymerization manner.
  • the polymer is a copolymer including a first structural unit, a second structural unit and a third structural unit, and the molar ratio of the first structural unit, the second structural unit and the third structural unit is within an appropriate range.
  • the polymer has the structural formula shown in Formula V,
  • a is selected from 0 to 5000
  • b and c are independently selected from 500 to 50000
  • d is selected from 10 to 5000.
  • a, b, c, and d represent the degree of polymerization of each structural unit, that is, the statistical average of the number of structural units contained in the polymer molecular chain, and do not necessarily mean that the structural units form a block of a certain length.
  • the polymer may be a random copolymer containing the structural units indicated.
  • the lithium oxygen group on the benzene ring in the polymer is more active.
  • the lithium oxygen group on the benzene ring can be oxidized into benzoquinone, releasing It produces lithium ions and maintains a high energy density during rapid charging and discharging.
  • the polymer has a weight average molecular weight of 20,000 to 2,000,000, optionally 100,000 to 1,000,000.
  • the weight average molecular weight of a polymer can be measured using conventional means in the art.
  • the weight average molecular weight of a polymer can be measured using laser light scattering techniques, which are well known to those skilled in the art. If the weight average molecular weight of the polymer is too low, the binding force to the active material is insufficient. If the weight average molecular weight of the polymer is too high, the processing performance of the cathode film layer formed by the polymer, cathode active material, and optional conductive agent will deteriorate.
  • the preparation method of the polymer includes the following steps:
  • the monomer corresponding to the first structural unit, the monomer corresponding to the second structural unit and the monomer corresponding to the third structural unit are mixed with an emulsifier, an initiator and a dispersion medium to form an emulsion, and the emulsion is heated to react to obtain a polymer.
  • the monomer corresponding to the first structural unit in the polymer has the structural formula shown in formula I-a,
  • R 1 and R 2 are independently selected from H or C 1-18 alkyl, optionally H or C 1-6 alkyl.
  • the monomer corresponding to the second structural unit in the polymer has the structural formula shown in formula II-a,
  • R 3 , R 4 , R 5 , R 6 and R 7 are independently selected from one of H, C 1 to 18 alkyl, C 1 to 18 alkoxy or lithium oxy, and R 3 , R 4. At least one of R 5 , R 6 and R 7 is lithium oxy group, optionally H, C 1 to 6 alkyl group, C 1 to 6 alkoxy group or lithium oxy group, R 8 is selected from H or C 6 ⁇ 18 aryl group, optionally H or phenyl.
  • the monomer corresponding to the third structural unit in the polymer has the structural formula shown in formula III-a,
  • R a and R b are selected from Or one of CN, R 9 and R 10 are independently selected from H or C 1-18 alkyl, optionally H or C 1-6 alkyl.
  • each raw material is first mixed with an emulsifier, an initiator and a dispersion medium to form an emulsion, and then a polymerization reaction is initiated at a certain temperature to prepare a polymer.
  • Its preparation process is simple, easy to control, and has high manufacturability.
  • the step of forming an emulsion specifically includes: mixing the monomer corresponding to the first structural unit, the monomer corresponding to the second structural unit, and the monomer corresponding to the third structural unit under stirring to obtain a mixture, and then The mixture is emulsified with emulsifier, initiator and dispersion medium under stirring to form an emulsion.
  • the mixture, emulsifier, initiator and dispersion medium are stirred for 20 to 30 minutes, and the stirring speed is 500 rpm. Therefore, appropriate stirring speed and stirring time make the emulsion droplets have a suitable size, thereby obtaining a polymer with a suitable molecular weight after polymerization.
  • the dispersion medium is water.
  • the emulsifier can be a commonly used surfactant suitable for aqueous emulsion polymerization, such as sodium lauryl sulfate emulsifier.
  • the initiator may be a common free radical initiator suitable for aqueous emulsion polymerization, such as ammonium persulfate. .
  • heating the emulsion to carry out the reaction specifically includes: passing protective gas into the emulsion, heating the emulsion to carry out the reaction, and then adjusting the pH value of the reactant to 6-8. Therefore, the introduction of protective gas can effectively prevent the occurrence of side reactions; adjusting the pH of the reactants to 6 to 8 can effectively prevent the polymer from releasing H + during the charging process of the lithium-ion battery, thus avoiding the occurrence of gas generation.
  • the mass ratio of the total mass of the monomer corresponding to the first structural unit, the monomer corresponding to the second structural unit and the monomer corresponding to the third structural unit, the emulsifier, the initiator and the dispersion medium is 100: (0.6 ⁇ 10):(0.6 ⁇ 2):(100 ⁇ 300).
  • the mass ratio of the total mass of the monomer corresponding to the first structural unit, the monomer corresponding to the second structural unit and the monomer corresponding to the third structural unit, the emulsifier, the initiator and the dispersion medium is 100:(2 ⁇ 3): (0.8 ⁇ 1.2): (110 ⁇ 130).
  • the mass ratio of each raw material is controlled to adjust the molecular weight of the prepared polymer, so that the prepared polymer can effectively exert the effect of a binder.
  • the heating temperature is greater than 80°C.
  • the heating time is 2h ⁇ 5h.
  • the heating temperature is 80°C to 120°C. More optionally, the heating temperature is 80°C to 100°C.
  • the heating time is 2h to 4h. More optionally, the heating time is 3 hours.
  • the present application also provides a pole piece, including the polymer sheet of the first aspect of the present application or the polymer prepared by the preparation method of the second aspect of the present application.
  • the pole piece is a positive pole piece.
  • the positive electrode sheet includes a positive electrode current collector and a positive electrode film layer disposed on at least one surface of the positive electrode current collector.
  • the positive electrode film layer includes a positive electrode active material and the polymer sheet of the first aspect of the application or is prepared by the preparation method of the second aspect of the application. obtained polymer.
  • the polymer serves as a binder to bind the positive electrode active materials together to form a positive electrode film layer, and to bond the positive electrode film layer to the positive electrode current collector.
  • the positive electrode current collector has two surfaces facing each other in its own 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 can 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.
  • Composite current collectors can be formed by forming metal materials (aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver and silver alloys, etc.) on polymer material substrates (such as polypropylene (PP), polyterephthalate It is formed on substrates such as ethylene glycol ester (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).
  • PP polypropylene
  • PBT polybutylene terephthalate
  • PS polystyrene
  • PE polyethylene
  • the cathode active material may be a cathode active material known in the art for batteries.
  • the cathode 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 of batteries can also be used. Only one type of these positive electrode active materials may be used alone, or two or more types may be used in combination.
  • lithium transition metal oxides may include, but are not limited to, lithium cobalt oxides (such as LiCoO 2 ), lithium nickel oxides (such as LiNiO 2 ), lithium manganese oxides (such as LiMnO 2 , LiMn 2 O 4 ), lithium Nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1/3 Co 1/3 Mn 1/3 O 2 (also referred to as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O 2 (can also be abbreviated to NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O 2 (can also be abbreviated to NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O 2 (can also be abbreviated to NCM 622 ), LiNi At least one of 0.8 Co 0.1 Mn 0.1 O 2 (also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as Li Li
  • the olivine structure contains Examples of lithium phosphates may include, but are not limited to, lithium iron phosphate (such as LiFePO 4 (also referred to as LFP)), composites of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO 4 ), lithium manganese phosphate and carbon. At least one of composite materials, lithium iron manganese phosphate, and composite materials of lithium iron manganese phosphate and carbon.
  • lithium iron phosphate such as LiFePO 4 (also referred to as LFP)
  • composites of lithium iron phosphate and carbon such as LiMnPO 4
  • LiMnPO 4 lithium manganese phosphate and carbon.
  • At least one of composite materials, lithium iron manganese phosphate, and composite materials of lithium iron manganese phosphate and carbon At least one of composite materials, lithium iron manganese phosphate, and composite materials of lithium iron manganese phosphate and carbon.
  • the positive electrode film layer optionally further includes a conductive agent.
  • the conductive agent may include 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 by dispersing the above-mentioned components for preparing the positive electrode sheet, such as positive active material, conductive agent, binder and any other components in a solvent (such as N -methylpyrrolidone) to form a positive electrode slurry; the positive electrode slurry is coated on the positive electrode current collector, and after drying, cold pressing and other processes, the positive electrode piece can be obtained.
  • a solvent such as N -methylpyrrolidone
  • FIG. 1 is a schematic diagram of a secondary battery according to an embodiment of the present application.
  • FIG. 2 is an exploded view of the secondary battery according to the embodiment of the present application shown in FIG. 1 .
  • Figure 3 is a schematic diagram of a battery module according to an embodiment of the present application.
  • Figure 4 is a schematic diagram of a battery pack according to an embodiment of the present application.
  • FIG. 5 is an exploded view of the battery pack according to an embodiment of the present application shown in FIG. 4 .
  • FIG. 6 is a schematic diagram of a power consumption device using a secondary battery as a power source according to an embodiment of the present application.
  • a fourth aspect of the present application provides a secondary battery, including the pole piece of the third aspect of the present application.
  • a secondary battery typically includes a positive electrode plate, a negative electrode plate, an electrolyte and a separator.
  • active ions are inserted and detached back and forth between the positive and negative electrodes.
  • the electrolyte plays a role in conducting ions between the positive and negative electrodes.
  • the isolation film is placed between the positive electrode piece and the negative electrode piece. It mainly prevents the positive and negative electrodes from short-circuiting and allows ions to pass through.
  • the positive electrode piece may be the above-mentioned electrode piece of the third aspect of the present application. Therefore, the previous description of the embodiments of the pole piece according to the present application is also applicable to the positive pole piece in the secondary battery, and the same content will not be described again.
  • 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, where the negative electrode film layer includes a negative electrode active material.
  • the negative electrode current collector has two opposite surfaces in its own 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.
  • 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 material.
  • the composite current collector can be formed by forming metal materials (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as polypropylene (PP), polyterephthalate It is formed on substrates such as ethylene glycol ester (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).
  • PP polypropylene
  • PBT polybutylene terephthalate
  • PS polystyrene
  • PE polyethylene
  • the negative active material may be a negative active material known in the art for batteries.
  • the negative 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, and the like.
  • 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 battery negative electrode active materials can also be used. Only one type of these negative electrode active materials may be used alone, or two or more types may be used in combination.
  • the negative electrode film layer optionally further includes a binder.
  • the binder can be selected from styrene-butadiene rubber (SBR), polyacrylic acid (PAA), polyacrylic acid sodium (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), poly At least one of methacrylic acid (PMAA) and carboxymethyl chitosan (CMCS).
  • the negative electrode film layer optionally further includes a conductive agent.
  • the conductive agent 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 optionally includes other auxiliaries, such as thickeners (such as sodium carboxymethyl cellulose (CMC-Na)) and the like.
  • auxiliaries such as thickeners (such as sodium carboxymethyl cellulose (CMC-Na)) and the like.
  • the negative electrode sheet can be prepared by dispersing the above-mentioned components for preparing the negative electrode sheet, such as negative active materials, conductive agents, binders and any other components in a solvent (such as deionized water) to form a negative electrode slurry; the negative electrode slurry is coated on the negative electrode current collector, and after drying, cold pressing and other processes, the negative electrode piece can be obtained.
  • a solvent such as deionized water
  • the electrolyte plays a role in conducting ions between the positive electrode piece and the negative electrode piece.
  • the type of electrolyte in this application can be selected according to needs.
  • the electrolyte can be liquid, gel, or completely solid.
  • the electrolyte is an electrolyte solution.
  • the electrolyte solution includes electrolyte salts and solvents.
  • the electrolyte salt may be NaPF 6 , NaClO 4 , NaBF 4 , KPF 6 , KClO 4 , KBF 4 , LiPF 6 , LiClO 4 , LiBF 4 , Zn(PF 6 ) 2 , Zn(ClO 4 ) 2 , one or more of Zn(BF 4 ) 2 .
  • the electrolyte salt can be selected from one or more of NaPF 6 , NaClO 4 , and NaBF 4 .
  • the solvent may be selected from the group consisting of ethylene carbonate, propylene carbonate, methylethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methylpropyl carbonate, ethylpropyl carbonate, Butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate At least one of ester, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone.
  • the electrolyte optionally further includes additives.
  • additives may include negative electrode film-forming additives, positive electrode film-forming additives, and may also include additives that can improve certain properties of the battery, such as additives that improve battery overcharge performance, additives that improve battery high-temperature or low-temperature performance, etc.
  • isolation membrane there is no particular restriction on the type of isolation membrane, and any well-known porous structure isolation membrane with good chemical stability and mechanical stability can be used.
  • 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 film can be a single-layer film or a multi-layer composite film, with no special restrictions. When the isolation film is a multi-layer composite film, the materials of each layer can be the same or different, and there is no particular limitation.
  • the positive electrode piece, the negative electrode piece, and the separator film can be made into an electrode assembly through a winding process or a lamination process.
  • the secondary battery may include an outer packaging.
  • the outer packaging can be used to package the above-mentioned electrode assembly and 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 bag, such as a bag-type soft bag.
  • the material of the soft bag may be plastic, and examples of the plastic include polypropylene, polybutylene terephthalate, polybutylene succinate, and the like.
  • FIG. 1 shows a square-structured secondary battery 5 as an example.
  • the outer package may include a housing 51 and a cover 53 .
  • the housing 51 may include a bottom plate and side plates connected to the bottom plate, and the bottom plate and the side plates enclose a receiving cavity.
  • the housing 51 has an opening communicating with the accommodation cavity, and the cover plate 53 can cover the opening to close the accommodation cavity.
  • the positive electrode piece, the negative electrode piece and the isolation film can be formed into the electrode assembly 52 through a winding process or a lamination process.
  • the electrode assembly 52 is packaged in the containing cavity.
  • the electrolyte soaks into 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 can be assembled into battery modules, and the number of secondary batteries contained in the battery module can be one or more. Those skilled in the art can select the specific number according to the application and capacity of the battery module.
  • FIG. 3 shows 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 .
  • the plurality of secondary batteries 5 can be fixed by fasteners.
  • the battery module 4 may further include a housing having a receiving space in which a plurality of secondary batteries 5 are received.
  • the above-mentioned battery modules can also be assembled into a battery pack.
  • the number of battery modules contained in the battery pack can be one or more. Those skilled in the art can select the specific number according to the application and capacity of the battery pack.
  • 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 2 and a lower box 3 .
  • the upper box 2 can be covered with the lower box 3 and form a closed space for accommodating the battery module 4 .
  • Multiple battery modules 4 can be arranged in the battery box in any manner.
  • the present application also provides an electrical device, which includes at least one of the secondary battery, battery module, or battery pack provided by the present application.
  • the secondary battery, battery module, or battery pack may be used as a power source for the electrical device, or may be used as an energy storage unit for the electrical device.
  • the electric 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, and electric golf carts). , electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc., but are not limited to these.
  • a secondary battery, a battery module or a battery pack can be selected according to its usage requirements.
  • FIG. 6 shows an electrical device as an example.
  • the electric device is a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, etc.
  • a battery pack or battery module can be used.
  • the device may be a mobile phone, a tablet, a laptop, etc.
  • This device is usually required to be thin and light, and secondary batteries can be used as power sources.
  • the polymer has the following structural formula:
  • a 500
  • b 4000
  • c 4500
  • d 1000.
  • Example 2 The difference between Example 2 and Example 1 is: 51.44g n-butyl acrylate, 22.29g monomer corresponding to the second structural unit, 4.97g N,N-dimethylacrylamide and 21.30g acrylonitrile, 500 is x, b is 4000, c is 4000, and d is 1500.
  • Example 3 The difference between Example 3 and Example 1 is: 49.10g n-butyl acrylate, 28.36g monomer corresponding to the second structural unit, 4.75g N, N-dimethylacrylamide and 17.79g acrylonitrile, a in the polymer is 500, b is 4000, c is 3500, and d is 2000.
  • the polymer has the following structural formula:
  • a 500
  • b 3000
  • c 4500
  • d 2000.
  • Example 5 The difference between Example 5 and Example 4 is: 37.52g ethyl acrylate, 37.95g monomer corresponding to the second structural unit, 4.64g N, N-dimethylacrylamide and 19.89g acrylonitrile, a in the polymer is 500 , b is 4000, c is 4000, and d is 1500.
  • Example 6 44.92g ethyl acrylate, 36.35g monomer corresponding to the second structural unit, 4.45g N, N-dimethylacrylamide and 14.28g acrylonitrile, a in the polymer is 500 , b is 5000, c is 3000, and d is 1500.
  • Example 7 The difference between Example 7 and Example 4 is: 33.57g ethyl acrylate, 38.81g monomer corresponding to the second structural unit, 4.75g N, N-dimethylacrylamide and 22.88g acrylonitrile polymer in which a is 500, b is 3500, c is 4500, and d is 1500.
  • Example 8 The difference between Example 8 and Example 4 is: 33.40g ethyl acrylate, 45.05g monomer corresponding to the second structural unit, 8.27g N, N-dimethylacrylamide and 13.28g acrylonitrile, a in the polymer is 1000 , b is 4000, c is 3000, and d is 2000.
  • Example 9 39.85g ethyl acrylate, 26.87g monomer corresponding to the second structural unit, 14.8g N, N-dimethylacrylamide and 18.48g acrylonitrile, a in the polymer is 1500 , b is 4000, c is 3500, and d is 1000.
  • the polymer is PVDF.
  • Comparative Example 2 no ethyl acrylate, 14.39g N,N-dimethylacrylamide and 33.37g acrylonitrile, 52.25g monomer corresponding to the second structural unit, the polymer has the following Structural formula.
  • a 1500
  • c 6500
  • d 2000
  • Comparative Example 3 there is no monomer corresponding to the second structural unit, 45.84g ethyl acrylate, 19.45g N,N-dimethylacrylamide and 34.71g acrylonitrile.
  • the polymer has the following Structural formula
  • a 1500
  • b 3500
  • c 5000
  • Comparative Example 4 The difference between Comparative Example 4 and Example 4 is that there is no N,N-dimethylacrylamide and acrylonitrile, 46.38g of ethyl acrylate, and 53.62g of the monomer corresponding to the second structural unit.
  • b 7000 and d is 3000.
  • Comparative Example 5 22.09g ethyl acrylate, 68.10g monomer corresponding to the second structural unit, 3.12g N,N-dimethylacrylamide and 6.69g acrylonitrile, a in the polymer is 500 , b is 3500, c is 2000, and d is 4000.
  • Comparative Example 6 The difference between Comparative Example 6 and Example 4 is: 45.92g ethyl acrylate, 3.54g monomer corresponding to the second structural unit, 12.99g N,N-dimethylacrylamide and 37.55g acrylonitrile, a in the polymer is 1000 , b is 3500, c is 5400, and d is 100.
  • Comparative Example 7 The difference between Comparative Example 7 and Example 4 is: 9.26g ethyl acrylate, 13.76g N,N-dimethylacrylamide and 27.00g acrylonitrile, 49.97g monomer corresponding to the second structural unit, a in the polymer is 1500 , b is 1000, c is 5500, and d is 2000.
  • Comparative Example 8 The difference between Comparative Example 8 and Example 4 is: 40.93g ethyl acrylate, 4.05g N,N-dimethylacrylamide and 10.85g acrylonitrile, 44.16g monomer corresponding to the second structural unit, a in the polymer is 500 , b is 5000, c is 2500, and d is 2000.
  • the polymer has the structural formula shown below,
  • a 500
  • b 3500
  • c 4000
  • d 2000
  • the positive electrode active material, conductive agent Super P, and binder (polymers obtained in the above-mentioned Examples 1 to 9 and Comparative Examples 1 to 9) were thoroughly stirred and mixed in an appropriate amount of NMP at a mass ratio of 95:3:2. It forms a uniform cathode slurry.
  • the viscosity of the positive electrode slurry is 6200 mPas and the positive electrode slurry will not gel, layer or settle within 48 hours; the solid content of the positive electrode slurry is 70%; the positive electrode slurry is coated on the positive electrode current collector aluminum foil On the surface, after drying and cold pressing, the positive electrode piece is obtained.
  • EC ethylene carbonate
  • DEC diethyl carbonate
  • DMC dimethyl carbonate
  • the positive pole piece, the isolation film, and the negative pole piece are stacked and wound in order to obtain an electrode assembly, in which the tabs with the magnetic layer attract each other.
  • the electrode assembly is placed in the outer packaging, the electrolyte prepared above is added, and after processes such as packaging, standing, formation, and aging, a secondary battery is obtained.
  • the secondary batteries prepared in the examples and comparative examples were charged at a constant current of 0.1C to the upper limit of the charge and discharge cut-off voltage (4.2V).
  • the charging capacity is recorded as the first cycle charging specific capacity of the secondary battery;
  • Examples 1 to 9 have all achieved good results.
  • the first-cycle charge specific capacity and the first-cycle discharge specific capacity of the lithium-ion battery are both higher, thereby improving the energy density of the secondary battery.
  • a polymer containing a lithium oxygen functional group monomer on the benzene ring is used as a binder in lithium ion batteries.
  • the lithium oxygen functional group on the benzene ring of the polymer is oxidized into benzoquinone, and Lithium ions are released, and the released lithium ions participate in the formation of an SEI film on the surface of the negative electrode during the first charge, thereby reducing the consumption of reversible lithium of the positive active material, improving the reversible capacity of the positive active material, and further increasing the energy density of lithium-ion batteries.
  • the phenol oxygen contained in the lithium oxygen group on the benzene ring in the polymer can be oxidized into benzoquinone and release lithium ions even at a lower operating voltage than the lithium-ion battery (usually 4.2V), thereby making the battery It can maintain high energy density during charging and discharging.
  • the first-cycle charge specific capacity and first-cycle discharge specific capacity of Examples 4 to 9 are generally higher than those of Examples 1 to 3. This is due to the lithium replenishment efficiency of the binder. It is enhanced with the increase of lithium oxygen functional groups.
  • the monomer corresponding to the second structural unit is an important factor affecting the properties of the polymer.
  • the quality of the monomer corresponding to the second structural unit has an impact on the first cycle charge specific capacity and first cycle discharge specific capacity of the lithium-ion battery, which also illustrates that the second structural unit corresponds to The monomer realizes the binder as another source of active lithium, which can supplement the loss of irreversible capacity active lithium due to the first charge and discharge.
  • the monomer corresponding to the first structural unit is also an important factor affecting the performance of the cathode plate.
  • the monomer corresponding to the first structural unit can give the polymer a certain flexibility and can effectively improve the adhesiveness of the polymer, thereby enabling the polymer to be used as a binder.
  • the comparative example Polymers 2 and 8 have poor adhesion.
  • the third structural unit is also an important factor affecting the performance of the cathode plate.
  • the polymer of Comparative Example 4 has poor solubility and is not easy to mix with the positive electrode active material and conductive agent.
  • the monomer corresponding to the third structural unit can give the polymer a certain solubility, so that the polymer can be used as a binder and evenly dispersed with the cathode active material and conductive agent, making it easy to process and manufacture.

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Abstract

Les modes de réalisation de la présente demande concernent un polymère et son procédé de préparation, une plaque d'électrode, une batterie secondaire, un module de batterie, un bloc-batterie et un dispositif électrique. Le polymère de la présente demande comprend une première unité structurelle dont la formule structurelle est représentée par la formule I, une deuxième unité structurelle dont la formule structurelle est représentée par la formule II, et une troisième unité structurelle dont la formule structurelle est représentée par la formule III, R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, Ra et Rb étant respectivement tels que définis dans le présent document. En tant qu'autre source active de lithium, le polymère de la présente demande peut reconstituer le lithium actif perdu lors de la perte irréversible de capacité au cours de la charge-décharge initiale.
PCT/CN2022/101939 2022-06-28 2022-06-28 Polymère et son procédé de préparation, plaque d'électrode, batterie secondaire, module de batterie, bloc-batterie et dispositif électrique WO2024000167A1 (fr)

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PCT/CN2022/101939 WO2024000167A1 (fr) 2022-06-28 2022-06-28 Polymère et son procédé de préparation, plaque d'électrode, batterie secondaire, module de batterie, bloc-batterie et dispositif électrique

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103509500A (zh) * 2012-06-26 2014-01-15 湖州欧美化学有限公司 用于锂离子二次电池的水性粘合剂
US20160049660A1 (en) * 2014-08-12 2016-02-18 Samsung Electronics Co., Ltd. Polymer, binder and negative electrode including the polymer, and lithium battery including the negative electrode
CN108987751A (zh) * 2017-05-31 2018-12-11 宁德时代新能源科技股份有限公司 一种粘结剂及其二次电池
CN109616629A (zh) * 2018-11-26 2019-04-12 中南大学 一种补锂正极活性材料、正极材料、锂离子电池及其制备和应用
CN109994732A (zh) * 2019-04-15 2019-07-09 上海电气国轩新能源科技有限公司 酚类锂盐化合物的应用、锂离子二次电池及其制备方法

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103509500A (zh) * 2012-06-26 2014-01-15 湖州欧美化学有限公司 用于锂离子二次电池的水性粘合剂
US20160049660A1 (en) * 2014-08-12 2016-02-18 Samsung Electronics Co., Ltd. Polymer, binder and negative electrode including the polymer, and lithium battery including the negative electrode
CN108987751A (zh) * 2017-05-31 2018-12-11 宁德时代新能源科技股份有限公司 一种粘结剂及其二次电池
CN109616629A (zh) * 2018-11-26 2019-04-12 中南大学 一种补锂正极活性材料、正极材料、锂离子电池及其制备和应用
CN109994732A (zh) * 2019-04-15 2019-07-09 上海电气国轩新能源科技有限公司 酚类锂盐化合物的应用、锂离子二次电池及其制备方法

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