WO2025112709A1 - 复合集流体、极片、二次电池以及用电装置 - Google Patents

复合集流体、极片、二次电池以及用电装置 Download PDF

Info

Publication number
WO2025112709A1
WO2025112709A1 PCT/CN2024/114336 CN2024114336W WO2025112709A1 WO 2025112709 A1 WO2025112709 A1 WO 2025112709A1 CN 2024114336 W CN2024114336 W CN 2024114336W WO 2025112709 A1 WO2025112709 A1 WO 2025112709A1
Authority
WO
WIPO (PCT)
Prior art keywords
layer
current collector
metal
composite current
thickness
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/CN2024/114336
Other languages
English (en)
French (fr)
Inventor
蔡启果
刘欣
黄起森
李铭领
李铖
刘向辉
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Contemporary Amperex Technology Co Ltd
Original Assignee
Contemporary Amperex Technology Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Contemporary Amperex Technology Co Ltd filed Critical Contemporary Amperex Technology Co Ltd
Publication of WO2025112709A1 publication Critical patent/WO2025112709A1/zh
Anticipated expiration legal-status Critical
Pending legal-status Critical Current

Links

Classifications

    • 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
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • H01M4/665—Composites
    • 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
    • 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
    • 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
    • H01M4/04—Processes of manufacture in general
    • 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
    • H01M4/04—Processes of manufacture in general
    • H01M4/0402—Methods of deposition of the material
    • H01M4/0404—Methods of deposition of the material by coating on electrode collectors
    • 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
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • 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
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • H01M4/665—Composites
    • H01M4/667—Composites in the form of layers, e.g. coatings
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present application relates to the technical field of secondary batteries, and in particular to a composite current collector, a pole piece, a secondary battery and an electrical device.
  • the first aspect of the present application provides a composite current collector, including a substrate layer, a bonding layer and a metal layer; the substrate layer has a first surface and a second surface relative to each other; the bonding layer and the metal layer are provided on at least one of the first surface and the second surface, and the bonding layer is located between the substrate layer and the metal layer; the metal layer includes a metal seed layer and a metal thickening layer, and the metal seed layer is located between the bonding layer and the metal thickening layer.
  • the bonding force between the substrate layer and the metal layer can be improved by setting the adhesive layer, and at the same time, the metal thickening layer is set on the metal seed layer, so that the metal layer has a suitable thickness. Therefore, in the above composite current collector, by designing the structure of the current collector, the metal layer and the substrate layer can have a good bonding force, and the metal layer can have a more suitable thickness.
  • the bonding layer comprises a polymer having a melting point of ⁇ 80°C.
  • the melting point of the polymer may be within this range. So that the bonding layer maintains good stability, reduces the risk of holes appearing on the surface of the bonding layer when preparing the metal seed layer, and further improves the bonding force between the metal seed layer and the bonding layer.
  • the bonding layer contains a polymer with a melting point of 80°C to 400°C.
  • the bonding layer contains at least one of polyolefin, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, polyurethane, epoxy resin, styrene-isoprene-styrene copolymer, styrene-butadiene-styrene copolymer, styrene-ethylene-butylene-styrene copolymer, styrene-ethylene-propylene-styrene copolymer, silicone rubber, phenolic resin, urea-formaldehyde resin and polyimide.
  • polyolefin ethylene-propylene copolymer
  • ethylene-vinyl acetate copolymer ethylene-vinyl alcohol copolymer
  • polyurethane epoxy resin
  • styrene-isoprene-styrene copolymer sty
  • the thickness of the bonding layer is 200 nm to 1500 nm.
  • the thickness of the bonding layer within this range can maintain a relatively suitable overall thickness of the composite current collector on the basis of exerting a good bonding effect, thereby reducing the risk of the composite current collector being too thick.
  • the thickness of the bonding layer is 300 nm to 700 nm.
  • the metal seed layer includes at least one of a sputtered metal seed layer, an evaporated metal seed layer, and a sprayed metal seed layer.
  • the thickness of the metal seed layer is 1 nm to 200 nm.
  • the metal seed layer within this thickness range is easy to prepare and can maintain good bonding with the bonding layer.
  • the thickness of the metal seed layer is 20 nm to 100 nm.
  • the metal seed layer includes at least one of copper, a copper alloy, aluminum, and an aluminum alloy.
  • the metal thickening layer includes an electroplated metal thickening layer.
  • the electroplated metal thickening layer may be a metal thickening layer formed by electroplating.
  • the metal seed layer has good conductivity, which facilitates electroplating to form the metal thickening layer.
  • the thickness of the metal thickening layer is 0.2 ⁇ m to 2 ⁇ m.
  • the thickness of the metal thickening layer within this range can make the metal layer have a relatively suitable thickness as a whole, so that the composite current collector takes into account a relatively suitable metal layer thickness and internal resistance.
  • the thickness of the metal thickening layer is 0.5 ⁇ m to 1.5 ⁇ m.
  • the substrate layer comprises at least one of polyamide, polyimide, polyethylene terephthalate, polybutylene terephthalate, poly(p-phenylene terephthalamide), polyethylene, polypropylene, polypropylene, polytetrafluoroethylene, polyvinylidene fluoride, polystyrene, polyvinyl chloride, acrylonitrile-butadiene-styrene copolymer, polyoxymethylene, epoxy resin, phenolic resin, silicone rubber and polycarbonate.
  • the substrate layer has a thickness of 2 ⁇ m to 10 ⁇ m, and optionally 3 ⁇ m to 8 ⁇ m.
  • the second aspect of the present application provides a method for preparing a composite current collector comprising the following steps:
  • the metal seed layer is prepared by at least one of sputtering, evaporation and spraying.
  • the metal thickening layer is prepared by electroplating.
  • a third aspect of the present application provides a pole piece, comprising at least one of the composite current collector and the composite current collector prepared by the preparation method.
  • a fourth aspect of the present application provides a secondary battery, comprising the pole piece.
  • a fifth aspect of the present application provides an electrical device, comprising at least one of the composite current collector, the composite current collector prepared by the preparation method, the pole piece, and the secondary battery.
  • 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 one embodiment of the present application shown in FIG. 1 .
  • FIG. 3 is a schematic diagram of an electrical device using a secondary battery as a power source according to an embodiment of the present application.
  • FIG. 4 is a schematic diagram of the structure of a composite current collector in one embodiment of the present application.
  • FIG. 5 is a schematic diagram of the structure of a composite current collector in another embodiment of the present application.
  • the "range” disclosed in the present application can be 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 the end values, and any end value can be included or excluded independently, 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 to 120 and 80 to 110 is listed for a specific parameter, it is understood that the range of 60 to 110 and 80 to 120 is also expected.
  • the numerical range "a to b" represents an abbreviation of any real number combination 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" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations.
  • a parameter is expressed as an integer ⁇ 2 it is equivalent to listing the parameter as, for example, integers 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.
  • a parameter is expressed as an integer selected from "2-10", it is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9 and 10.
  • each step is written does not mean a strict order of execution and does not constitute any limitation on the implementation process, and the detailed order of execution of each step should be determined by its function and possible internal logic. If there is no special explanation, all steps of the present application can be performed sequentially or randomly, preferably sequentially.
  • the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or steps (b) and (a) performed sequentially.
  • the method may also include step (c), indicating that step (c) can be added to the method in any order, for example, the method may include steps (a), (b) and (c), or steps (a), (c) and (b), or steps (c), (a) and (b), etc.
  • A (such as B) means that B is a non-limiting example of A, and it can be understood that A is not limited to B.
  • An embodiment of the present application provides a composite current collector.
  • the composite current collector includes a substrate layer, a bonding layer and a metal layer.
  • the substrate layer has a first surface and a second surface relative to each other.
  • a bonding layer and a metal layer are provided on at least one of the first surface and the second surface, and the bonding layer is located between the substrate layer and the metal layer.
  • the metal layer includes a metal seed layer and a metal thickening layer, and the metal seed layer is located between the bonding layer and the metal thickening layer.
  • the bonding force between the substrate layer and the metal layer can be improved by setting the bonding layer, and at the same time, the metal thickening layer is set on the metal seed layer, so that the metal layer can have a suitable thickness. Therefore, in the composite current collector of this embodiment, by designing the structure of the current collector, the metal layer and the substrate layer can have a good bonding force, and the metal layer can have a more suitable thickness.
  • FIG. 4 shows the structure of a composite current collector 3 in one embodiment of the present application.
  • the composite current collector 3 includes a substrate layer 31, a bonding layer 32, and a metal layer.
  • the substrate layer 31 has a first surface and a second surface relative to each other.
  • the bonding layer 32 and the metal layer are provided on the first surface or the second surface, and the bonding layer 32 is located between the substrate layer 31 and the metal layer.
  • the metal layer includes a metal seed layer 33 and a metal thickening layer 34, and the metal seed layer 33 is located between the bonding layer 32 and the metal thickening layer 34.
  • FIG. 5 shows the structure of a composite current collector 3 in another embodiment of the present application.
  • the composite current collector 3 includes a substrate layer 31, a bonding layer 32, and a metal layer.
  • the substrate layer 31 has a first surface and a second surface relative to each other.
  • the bonding layer 32 and the metal layer are provided on the first surface and the second surface, and the bonding layer 32 is located between the substrate layer 31 and the metal layer.
  • the metal layer includes a metal seed layer 33 and a metal thickening layer 34, and the metal seed layer 33 is located between the bonding layer 32 and the metal thickening layer 34.
  • the thickness of the metal layer can reduce the overall thickness and manufacturing cost of the composite current collector to a certain extent.
  • a metal layer with a smaller thickness may bring a larger internal resistance, so it is necessary to make the metal layer The thickness is kept in a relatively suitable range.
  • the metal layer can have a relatively suitable thickness, and at the same time, the substrate layer and the metal layer have a good bonding force.
  • the bonding layer comprises a polymer having a melting point of ⁇ 80 degrees Celsius (°C).
  • the bonding layer comprises a polymer having a melting point of 80°C to 400°C.
  • the melting point of the polymer within this range can maintain good stability of the bonding layer, reduce the risk of holes appearing on the surface of the bonding layer when preparing the metal seed layer, and further improve the bonding force between the metal seed layer and the bonding layer.
  • the reduction of holes can also reduce the risk of lithium precipitation in the pole piece.
  • the bonding layer comprises at least one of polyolefin, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, polyurethane, epoxy resin, styrene-isoprene-styrene copolymer, styrene-butadiene-styrene copolymer, styrene-ethylene-butylene-styrene copolymer, styrene-ethylene-propylene-styrene copolymer, silicone rubber, phenolic resin, urea-formaldehyde resin and polyimide.
  • the melting point of the polymer contained in the adhesive layer can be 80°C, 100°C, 120°C, 150°C, 180°C, 200°C, 220°C, 250°C, 280°C, 300°C, 320°C, 350°C, 380°C, 400°C, etc.
  • the melting point of the bonding layer is greater than the melting point of the substrate layer. In this case, it is not easy to form holes on the surface of the bonding layer when preparing the metal seed layer, which is conducive to further improving the bonding force between the metal seed layer and the bonding layer.
  • the thickness of the bonding layer is 200 nanometers (nm) to 1500nm.
  • the thickness of the bonding layer within this range can keep the composite current collector at a relatively suitable overall thickness on the basis of exerting a good bonding effect, reducing the risk of excessive thickness of the composite current collector.
  • the thickness of the bonding layer can be 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1000nm, 1100nm, 1200nm, 1300nm, 1400nm, 1500nm, etc. Further optionally, the thickness of the bonding layer is 300nm to 700nm.
  • the metal seed layer includes at least one of a sputtered metal seed layer, an evaporated metal seed layer, and a sprayed metal seed layer.
  • the sputtered metal seed layer may be a metal seed layer formed by a sputtering method such as magnetron sputtering.
  • the evaporated metal seed layer may be a metal seed layer formed by evaporation.
  • the sprayed metal seed layer may be a metal seed layer formed by spraying.
  • the sputtered metal seed layer, the evaporated metal seed layer, and the sprayed metal seed layer may maintain good adhesion with the bonding layer, which is beneficial to improving the overall stability of the composite current collector structure.
  • the metal seed layer includes a sprayed metal seed layer. The temperature of the sprayed metal seed layer is relatively low during the formation process, which can reduce the impact on the bonding layer when preparing the metal seed layer and reduce the risk of holes in the bonding layer due to high temperature.
  • the thickness of the metal seed layer is 1 nm to 200 nm.
  • the metal seed layer within this thickness range is easy to prepare and can maintain good bonding strength with the bonding layer. and spraying.
  • the thickness of the metal seed layer can be 1nm, 5nm, 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 120nm, 150nm, 180nm, etc. Further optionally, the thickness of the metal seed layer is 20nm to 100nm.
  • the metal seed layer includes at least one of copper, a copper alloy, aluminum, and an aluminum alloy.
  • the metal thickening layer includes an electroplated metal thickening layer. It is understood that the electroplated metal thickening layer can be a metal thickening layer formed by electroplating.
  • the metal seed layer has good conductivity, which is convenient for electroplating to form the metal thickening layer.
  • the thickness of the metal thickening layer is 0.2 micrometers ( ⁇ m) to 2 ⁇ m.
  • the thickness of the metal thickening layer within this range can make the metal layer as a whole have a more suitable thickness, so that the composite current collector takes into account a more suitable metal layer thickness and internal resistance.
  • the thickness of the metal thickening layer can be 0.2 ⁇ m, 0.5 ⁇ m, 0.8 ⁇ m, 1 ⁇ m, 1.2 ⁇ m, 1.5 ⁇ m, 1.5 ⁇ m, 1.8 ⁇ m, 2 ⁇ m, etc. Further optionally, the thickness of the metal thickening layer is 0.5 ⁇ m to 1.5 ⁇ m.
  • the substrate layer comprises at least one of polyamide, polyimide, polyethylene terephthalate, polybutylene terephthalate, poly(p-phenylene terephthalamide), polyethylene, polypropylene, polypropylene, polytetrafluoroethylene, polyvinylidene fluoride, polystyrene, polyvinyl chloride, acrylonitrile-butadiene-styrene copolymer, polyoxymethylene, epoxy resin, phenolic resin, silicone rubber and polycarbonate.
  • the thickness of the substrate layer is 2 ⁇ m to 10 ⁇ m.
  • the thickness of the substrate layer can be 2 ⁇ m, 3 ⁇ m, 4 ⁇ m, 5 ⁇ m, 6 ⁇ m, 7 ⁇ m, 8 ⁇ m, 9 ⁇ m, 10 ⁇ m, etc. Further optionally, the thickness of the substrate layer is 3 ⁇ m to 8 ⁇ m.
  • Another embodiment of the present application provides a method for preparing a composite current collector.
  • the method for preparing the composite current collector comprises the following steps: providing a substrate layer, the substrate layer having a first surface and a second surface opposite to each other. Sequentially preparing a bonding layer, a metal seed layer and a metal thickening layer on the first surface and/or the second surface.
  • the metal seed layer is prepared by at least one of sputtering, evaporation and spraying, and the metal thickening layer is prepared by electroplating.
  • the method for preparing the bonding layer includes: coating a slurry containing raw materials for the bonding layer on a surface of the substrate layer, and then aging to form the bonding layer.
  • the slurry can be coated by gravure coating.
  • a metal seed layer is prepared on the surface of the slurry and then matured. This can improve the surface hardness of the bonding layer on the one hand, and further improve the bonding force between the metal seed layer and the bonding layer on the other hand.
  • the maturation temperature is 80°C to 90°C
  • the maturation time is 4 seconds (s) to 8s.
  • the cured product is rolled to ensure that the metal seed layer and the bonding layer are fully adhered to each other and to improve the uniformity of the thickness of the bonding layer.
  • the preparation method of the composite current collector includes the following steps: coating a slurry containing raw materials for a bonding layer on at least one surface of a substrate layer; preparing a metal seed layer on the surface of the slurry; maturing the slurry; rolling the matured product; maturing again after rolling; and preparing a metal thickening layer on the surface of the metal seed layer of the matured product.
  • the two surfaces of the substrate layer can be operated separately or simultaneously.
  • the secondary battery includes the above-mentioned electrode sheet.
  • Another embodiment of the present application provides an electrical device, which includes at least one of the composite current collector, the composite current collector prepared by the preparation method, the pole piece, and the secondary battery.
  • a secondary battery includes a positive electrode sheet, a negative electrode sheet, an electrolyte and a separator.
  • active ions are embedded and released back and forth between the positive electrode sheet and the negative electrode sheet.
  • the electrolyte plays the role of conducting ions between the positive electrode sheet and the negative electrode sheet.
  • the separator is set between the positive electrode sheet and the negative electrode sheet, mainly to prevent the positive and negative electrodes from short-circuiting, while allowing ions to pass through.
  • 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, wherein the positive electrode film layer includes a positive electrode active material.
  • the positive electrode current collector has two surfaces opposite to each other in its thickness direction, and the positive electrode active material 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.
  • aluminum foil may be used as the metal foil.
  • the composite current collector may be the above-mentioned composite current collector.
  • the composite current collector may also include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer.
  • the composite current collector may be obtained by forming a metal material on a polymer material substrate.
  • the metal material may include one or more of aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy.
  • non-limiting examples of the polymer material substrate may include one or more of substrates such as polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.
  • substrates such as polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.
  • 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 one or more of the following materials: an olivine-structured lithium-containing phosphate, Lithium transition metal oxides 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 can also be used. These positive electrode active materials can be used alone or in combination of two or more.
  • lithium transition metal oxides may include, but are not limited to, one or more of lithium cobalt oxide (such as LiCoO2 ), lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide and their modified compounds.
  • lithium-containing phosphates with an olivine structure may include, but are not limited to, one or more of lithium iron phosphate, a composite material of lithium iron phosphate and carbon, lithium manganese phosphate, a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon.
  • Non-limiting examples of lithium cobalt oxides may include LiCoO2 ; non-limiting examples of lithium nickel oxides may include LiNiO2 ; non-limiting examples of lithium manganese oxides may include LiMnO2 , LiMn2O4 , etc .; non-limiting examples of lithium nickel cobalt manganese oxides may include 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 ) , etc.
  • Non-limiting examples of lithium nickel cobalt aluminum oxide may include LiNi 0.8 Co 0.15 Al 0.05 O 2 .
  • the positive electrode active material layer may also optionally include a binder.
  • the binder may include one or more of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorine-containing acrylate resin.
  • PVDF polyvinylidene fluoride
  • PTFE polytetrafluoroethylene
  • PTFE polytetrafluoroethylene
  • vinylidene fluoride-tetrafluoroethylene-propylene terpolymer vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer
  • the positive electrode active material layer may further include a conductive agent.
  • the conductive agent may include one or more 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 the following method: 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 to form a positive electrode slurry; the positive electrode slurry is coated on at least one side of the positive electrode collector, and after drying, cold pressing and other processes, the positive electrode sheet can be obtained.
  • the type of solvent can be selected from but not limited to any one of the aforementioned embodiments, such as N-methylpyrrolidone (NMP).
  • NMP N-methylpyrrolidone
  • the surface of the positive electrode collector coated with the positive electrode slurry can be on a single surface of the positive electrode collector or on both surfaces of the positive electrode collector.
  • the surface of the positive electrode collector coated with the positive electrode slurry can be on a single surface of the positive electrode collector or on both surfaces of the positive electrode collector.
  • the solid content of the positive electrode slurry can be 40 weight % (wt%) to 80wt%.
  • the viscosity of the positive electrode slurry at room temperature can be adjusted to 5000 millipascals ⁇ seconds (mPa ⁇ s) to 25000 mPa ⁇ s.
  • the coating unit area density based on dry weight (excluding solvent) can be 15 mg/ cm2 to 35 mg/ cm2 .
  • the compaction density of the positive electrode sheet can be 3.0 g/ cm3 to 3.6 g/ cm3 , and can be 3.3 g/ cm3 to 3.5 g/ cm3 .
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector, wherein the negative electrode active material layer includes a negative electrode active material.
  • the negative electrode current collector has two surfaces opposite to each other in its own thickness direction, and the negative electrode active material 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.
  • copper foil may be used as the metal foil.
  • the composite current collector may be the above-mentioned composite current collector.
  • the composite current collector may also include a polymer material base layer and a metal layer formed on at least one surface of the polymer material substrate.
  • the composite current collector may be obtained by forming a metal material on a polymer material substrate.
  • non-limiting examples of the metal material may include one or more of copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy.
  • non-limiting examples of the polymer material substrate may include one or more of substrates such as polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.
  • substrates such as polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.
  • the negative electrode active material may adopt the negative electrode active material for batteries known in the art.
  • the negative electrode active material may include one or more 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 include one or more of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys.
  • the tin-based material may include one or more 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 active material layer may further include a binder.
  • the binder may include one or more 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 active material layer may further include a conductive agent, which may include one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.
  • a conductive agent which may include one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.
  • the negative electrode active material layer may further 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 by the following method: dispersing the above components for preparing the negative electrode sheet, such as the negative electrode active material, the conductive agent, the binder and any other components in a solvent (a non-limiting example of the solvent is deionized water) to form a negative electrode slurry; coating the negative electrode slurry on at least one side of the negative electrode current collector, drying, After cold pressing and other processes, the negative electrode sheet can be obtained.
  • the surface of the negative electrode collector coated with the negative electrode slurry can be on a single surface of the negative electrode collector or on both surfaces of the negative electrode collector.
  • the solid content of the negative electrode slurry can be 40wt% to 60wt%.
  • the viscosity of the negative electrode slurry at room temperature can be adjusted to 2000mPa ⁇ s to 10000mPa ⁇ s.
  • the coating unit area density based on dry weight (excluding solvent) can be 75 grams per square meter (g/m 2 ) to 220g/m 2 .
  • the compacted density of the negative electrode sheet can be 1.0g/cm 3 to 1.8g/cm 3 .
  • the electrolyte has the function of conducting ions between the positive electrode and the negative electrode.
  • the present application has no particular restrictions on the type of electrolyte, which can be selected according to needs.
  • the electrolyte can be liquid, gel or all-solid.
  • the electrolyte is an electrolyte solution, which includes an electrolyte salt and a solvent.
  • the electrolyte salt may include one or more of lithium hexafluorophosphate (LiPF 6 ), lithium tetrafluoroborate (LiBF 4 ), lithium perchlorate (LiClO 4 ), lithium hexafluoroarsenate (LiAsF 6 ), lithium bisfluorosulfonyl imide (LiFSI), lithium bistrifluoromethanesulfonyl imide (LiTFSI), lithium trifluoromethanesulfonate (LiTFS), lithium difluorophosphate (LiPO 2 F 2 ), lithium difluorooxalatoborate (LiDFOB), lithium dioxalatoborate (LiBOB), lithium difluorobisoxalatophosphate (LiDFOP), and lithium tetrafluorooxalatophosphate (LiTFOP).
  • LiPF 6 lithium hexafluorophosphate
  • LiBF 4 lithium perchlorate
  • the solvent may include ethylene carbonate (EC, ), propylene carbonate (PC, ), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), butylene carbonate
  • EC ethylene carbonate
  • PC propylene carbonate
  • EMC diethyl carbonate
  • DMC dimethyl carbonate
  • DPC dipropyl carbonate
  • MPC methyl propyl carbonate
  • EPC methyl propyl carbonate
  • EPC methyl propyl carbonate
  • EPC methyl propyl carbonate
  • MPC methyl propyl carbonate
  • EPC methyl propyl carbonate
  • EPC methyl propyl carbonate
  • MPC methyl propyl carbonate
  • EPC methyl propyl carbonate
  • EPC methyl propyl carbonate
  • MPC methyl
  • 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 additives in the electrolyte may include, but are not limited to, one or more of fluoroethylene carbonate (FEC), difluoroethylene carbonate (DFEC), trifluoromethylethylene carbonate (TFPC), and the like.
  • FEC fluoroethylene carbonate
  • DFEC difluoroethylene carbonate
  • TFPC trifluoromethylethylene carbonate
  • 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 may include one or more of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride.
  • the isolation membrane may be a single-layer film or a multi-layer composite film, without particular limitation.
  • the materials of each layer may be the same or different, without particular limitation.
  • the isolation film has a thickness of 6 ⁇ m to 40 ⁇ m, and may be 12 ⁇ m to 20 ⁇ m.
  • the positive electrode sheet, the negative electrode sheet and the separator can 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 can be a hard shell, such as a hard plastic shell, an aluminum shell, a steel shell, etc.
  • the outer packaging of the secondary battery can also be a soft package, such as a bag-type soft package.
  • the material of the soft package can be plastic, and further, non-limiting examples of plastic can include one or more of polypropylene, polybutylene terephthalate, and polybutylene succinate.
  • the secondary battery includes at least one battery cell.
  • the secondary battery may include one or more battery cells.
  • battery cell refers to a basic unit that can realize the mutual conversion of chemical energy and electrical energy, and further, generally speaking, at least includes a positive electrode sheet, a negative electrode sheet and an electrolyte.
  • active ions are embedded and released back and forth between the positive electrode sheet and the negative electrode sheet.
  • the electrolyte plays the role of conducting active ions between the positive electrode sheet and the negative electrode sheet.
  • FIG1 is a battery cell 1 of a square structure as an example.
  • the outer packaging may include a shell 11 and a cover plate 13.
  • the shell 11 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 11 has an opening connected to the receiving cavity, and the cover plate 13 can be covered on the opening to close the receiving cavity.
  • the positive electrode sheet, the negative electrode sheet and the isolation membrane can form an electrode assembly 12 through a winding process or a lamination process.
  • the electrode assembly 12 is encapsulated in the receiving cavity.
  • the electrolyte is infiltrated in the electrode assembly 12.
  • the number of electrode assemblies 12 contained in the battery cell 1 may be one or more, and those skilled in the art can select according to actual needs.
  • the secondary battery may be a battery module or a battery pack.
  • the battery module includes at least one battery cell.
  • the number of battery cells contained in the battery module can be one or more, and those skilled in the art can select a suitable number according to the application and capacity of the battery module.
  • the plurality of battery cells may be arranged in sequence along the length direction of the battery module. Of course, they may also be arranged in any other manner. Further, the plurality of battery cells may be fixed by fasteners.
  • the battery module may further include a housing having an accommodation space, and the plurality of battery cells are accommodated in the accommodation space.
  • the battery modules may be assembled into a battery pack.
  • the battery pack may contain one or more battery modules. Those skilled in the art may select a suitable number according to the application and capacity of the battery pack.
  • the battery pack may include a battery box and a plurality of battery modules disposed in the battery box.
  • the battery box includes an upper box body and a lower box body, and the upper box body can be covered on the lower box body to form a closed space for accommodating the battery modules.
  • the plurality of battery modules can be arranged in the battery box in any manner.
  • the present application also provides an electrical device, which includes a secondary battery provided by the present application.
  • the secondary battery can be used as a power source for the electrical device, or as an energy storage unit for the electrical device.
  • the electrical device may include mobile devices, electric vehicles, electric trains, ships and satellites, energy storage systems, etc., but are not limited thereto.
  • the mobile device may be, for example, a mobile phone, a laptop computer, etc.;
  • the electric vehicle may be, for example, a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric bicycle, an electric scooter, an electric golf cart, an electric truck, etc., but are not limited thereto.
  • a secondary battery can be selected according to its usage requirements.
  • Fig. 3 is an example of an electric device 2.
  • the electric device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc.
  • 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.
  • S103 baking the product obtained in S102 at 80° C. to 90° C. for 4 to 8 seconds to mature the slurry to form a bonding layer.
  • S106 Electroplating the surface of the metal seed layer of the product obtained in S105 to prepare a metal thickening layer.
  • the electroplating speed is 4 meters/minute (m/min) to 8 m/min. After electroplating, the composite current collector in this embodiment is obtained.
  • S103 baking the product obtained in S102 at 80° C. to 90° C. for 4 to 8 seconds to mature the slurry to form a bonding layer.
  • S106 preparing a metal seed layer on the surface of the slurry by magnetron sputtering.
  • S107 Bake the product obtained in S106 at 80° C. to 90° C. for 4 to 8 seconds to mature the slurry to form a bonding layer.
  • S110 Electroplating the surfaces of the two metal seed layers of the product obtained in S109 simultaneously to prepare a metal thickening layer.
  • the electroplating speed is 4 m/min to 8 m/min. After electroplating, the composite current collector in this embodiment is obtained.
  • Example 3 Compared with Example 2, the differences between Examples 3 to 18 are that the material of the substrate layer, the thickness of the substrate layer, the material of the bonding layer, the thickness of the bonding layer, the material of the metal seed layer, the preparation method of the metal seed layer, the thickness of the metal seed layer, the thickness of the metal thickening layer, etc. are different. The details are shown in Table 1.
  • Comparative Examples 1 to 3 Compared with Example 2, the differences of Comparative Examples 1 to 3 are that the composite current collector does not include a bonding layer, and the materials of the substrate layer are different.
  • (1) Metal layer peel strength test After laminating the sample with the non-corona surface of the EAA film, cover the EAA film with 12 ⁇ m PET and place it on a heat sealer at a temperature of 120°C and a pressure of 0.2 MPa for lamination. Cut the sample after lamination into a sample with a length of 100 mm and a width of 20 mm, and use 3M double-sided tape to stick the non-laminated surface of the metal layer on a steel plate; clamp the sample on the fixture of the tensile machine with a spacing of 50 mm and a speed of 300 mm/min for a 180°C peel test, read the peel force and convert it into Newton/meter (N/m), and take the average peel force of 5 parallel samples.
  • N/m Newton/meter
  • Composite current collector hole test Use an online CCD high-speed camera to test the number of holes in a composite current collector with a length of 1000 meters (m), and then divide it by the area of the current collector in the test section to calculate the number of holes per square meter.
  • Composite current collector square resistance test Use a four-probe square resistance tester to test the square resistance of the large surface of the sample metal layer. Randomly test 30 points and take the average square resistance of the 30 points.
  • the unit of the thickness of the substrate layer is ⁇ m.
  • the melting point indicates the melting point of the polymer contained in the adhesive layer, and the unit is °C.
  • the unit of the thickness of the adhesive layer is nm.
  • the unit of the thickness of the metal seed layer is nm.
  • the unit of the thickness of the metal thickening layer is ⁇ m.
  • the unit of the metal layer peel strength is N/m.
  • the unit of the number of holes is pieces/square meter (pieces/m 2 ).
  • the unit of the square resistance is milliohm per square (m ⁇ / ⁇ ).

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Composite Materials (AREA)
  • Cell Electrode Carriers And Collectors (AREA)

Abstract

一种复合集流体、极片、二次电池以及用电装置。复合集流体包括基材层、粘结层以及金属层；所述基材层具有相对的第一表面和第二表面；所述第一表面和/或所述第二表面上设有所述粘结层和所述金属层，所述粘结层位于所述基材层和所述金属层之间；所述金属层包括金属种子层和金属加厚层，所述金属种子层位于所述粘结层和所述金属加厚层之间。所述复合集流体中，通过对集流体的结构进行设计，可以使金属层和基材层之间具有较好的结合力，同时使金属层具有较为合适的厚度。

Description

复合集流体、极片、二次电池以及用电装置
相关申请
本申请要求2023年11月27日申请的，申请号为2023116012671，名称为“复合集流体、极片、二次电池以及用电装置”的中国专利申请的优先权，在此将其全文引入作为参考。
技术领域
本申请涉及二次电池技术领域，尤其涉及一种复合集流体、极片、二次电池以及用电装置。
背景技术
这里的陈述仅提供与本申请有关的背景信息，而不必然构成现有技术。
与金属集流体相比，复合集流体具有安全性能较高的优点。在的复合集流体中，由于基材层通常是由绝缘材料制备的，金属层和绝缘材料之间性能的差异制约了金属层和基材层之间结合力的改善。导致在传统的复合集流体中，为了使金属层与基材层具有较好的结合力，往往只能得到厚度较小的金属层。但是厚度较小的金属层具有较大的内阻，可能会给二次电池带来较大的内阻，影响电池的倍率性能。因此，传统的复合集流体中，金属层和基材层之间良好的结合力与合适的金属层厚度这两个方面往往难以较好地兼顾。
发明内容
为了实现上述目的，本申请的第一方面提供了一种复合集流体，包括基材层、粘结层以及金属层；所述基材层具有相对的第一表面和第二表面；所述第一表面和所述第二表面两者中的至少一者上设有所述粘结层和所述金属层，所述粘结层位于所述基材层和所述金属层之间；所述金属层包括金属种子层和金属加厚层，所述金属种子层位于所述粘结层和所述金属加厚层之间。
上述复合集流体中，通过粘结层的设置可以改善基材层和金属层之间的结合力，同时，金属加厚层在金属种子层之上设置，可以使金属层具有合适的厚度。因此，在上述复合集流体中，通过对集流体的结构进行设计，可以使金属层和基材层之间具有较好的结合力，同时使金属层具有较为合适的厚度。
在一些实施方式中，所述粘结层包含熔点≥80℃的聚合物。聚合物的熔点在该范围内可 以使粘结层保持良好的稳定性，降低制备金属种子层时，粘结层表面出现孔洞的风险，进一步提高金属种子层与粘结层之间的结合力。可选地，所述粘结层包含熔点为80℃～400℃的聚合物。可选地，所述粘结层包含聚烯烃、乙烯-丙烯共聚物、乙烯-醋酸乙烯共聚物、乙烯-乙烯醇共聚物、聚氨酯、环氧树脂、苯乙烯-异戊二烯-苯乙烯共聚物、苯乙烯-丁二烯-苯乙烯共聚物、苯乙烯-乙烯-丁烯-苯乙烯共聚物、苯乙烯-乙烯-丙烯-苯乙烯共聚物、硅橡胶、酚醛树脂、脲醛树脂以及聚酰亚胺中的至少一种。
在一些实施方式中，所述粘结层的厚度为200nm～1500nm。粘结层的厚度在该范围内可以在发挥较好粘结效果的基础上使复合集流体保持较为合适的整体厚度，降低复合集流体出现厚度过大的风险。可选地，所述粘结层的厚度为300nm～700nm。
在一些实施方式中，所述金属种子层包括溅射金属种子层、蒸镀金属种子层以及喷涂金属种子层中的至少一种。
在一些实施方式中，所述金属种子层的厚度为1nm～200nm。该厚度范围内的金属种子层便于制备得到，且能够与粘结层保持较好的结合力。可选地，所述金属种子层的厚度为20nm～100nm。
在一些实施方式中，所述金属种子层包含铜、铜合金、铝以及铝合金中的至少一种。
在一些实施方式中，所述金属加厚层包括电镀金属加厚层。电镀金属加厚层可以是通过电镀方式形成的金属加厚层。金属种子层具有较好的导电性，便于电镀形成金属加厚层。
在一些实施方式中，所述金属加厚层的厚度为0.2μm～2μm。金属加厚层的厚度在该范围内可以使金属层整体具有较为合适的厚度，使复合集流体兼顾较为合适的金属层厚度和内阻。可选地，所述金属加厚层的厚度为0.5μm～1.5μm。
在一些实施方式中，所述基材层包含聚酰胺、聚酰亚胺、聚对苯二甲酸乙二醇酯、聚对苯二甲酸丁二醇酯、聚对苯二甲酰对苯二胺、聚乙烯、聚丙烯、聚丙乙烯、聚四氟乙烯、聚偏氟乙烯、聚苯乙烯、聚氯乙烯、丙烯腈-丁二烯-苯乙烯共聚物、聚甲醛、环氧树脂、酚醛树脂、硅橡胶以及聚碳酸酯中的至少一种。
在一些实施方式中，所述基材层的厚度为2μm～10μm，可选地为3μm～8μm。
本申请第二方面提供了一种复合集流体的制备方法包括如下步骤：
提供基材层，所述基材层具有相对的第一表面和第二表面；
在所述第一表面和/或所述第二表面依次制备粘结层、金属种子层和金属加厚层。
在一些实施方式中，所述金属种子层通过溅射、蒸镀以及喷涂中的至少一种方式制备。
在一些实施方式中，所述金属加厚层通过电镀的方式制备。
本申请第三方面提供了一种极片，包括所述复合集流体和所述制备方法制备的复合集流体中的至少一种。
本申请第四方面提供了一种二次电池，包括所述极片。
本申请第五方面提供了一种用电装置，包括所述复合集流体、所述制备方法制备的复合集流体、所述极片以及所述二次电池中的至少一种。
附图说明
为了更好地描述和说明本申请提供的实施例或示例，可以参考一幅或多幅附图。用于描述附图的附加细节或示例不应当被认为是对所公开的申请、目前描述的实施例或示例以及目前理解的这些申请的最佳模式中的任何一者的范围的限制。而且在全部附图中，用相同的附图标号表示相同的部件。在附图中：
图1为本申请一实施方式的二次电池的示意图。
图2为图1所示的本申请一实施方式的二次电池的分解图。
图3为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。
图4为本申请一实施方式中复合集流体的结构示意图。
图5为本申请另一实施方式中复合集流体的结构示意图。
附图标记说明：
1、二次电池；11、壳体；12、电极组件；13、盖板；2、用电装置；3、复合集流体；31、
基材层；32、粘结层；33、金属种子层；34、金属加厚层。
具体实施方式
为了便于理解本申请，下面将参照相关附图对本申请进行更全面的描述。附图中给出了本申请的较佳实施例。但是，本申请可以以许多不同的形式来实现，并不限于本文所描述的实施例。相反地，提供这些实施例的目的是使对本申请的公开内容的理解更加透彻全面。
除非另有定义，本文所使用的所有的技术和科学术语与属于本申请的技术领域的技术人员通常理解的含义相同。本文中在本申请的说明书中所使用的术语只是为了描述具体的实施例的目的，不是旨在于限制本申请。本文所使用的术语“和/或”包括一个或多个相关的所列项目的任意的和所有的组合。
本申请所公开的“范围”可以采用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，任一个端值可以独立地被包括或不被包括，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，且如果还列出了最大范围值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，则相当于列出了该参数为例如整数2、3、4、5、6、7、8、9、10、11、12等。比如，当表述某个参数为选自“2～10”的整数，相当于列出了整数2、3、4、5、6、7、8、9和10。
本申请中涉及“多个”、“多种”等，如无特别限定，指在数量上大于2或等于2。例如，“一种或多种”表示一种或大于等于两种。
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。
在本文中提及“实施例”意味着，结合实施例描述的特定特征、结构或特性可以包含在本申请的至少一个实施例或实施方式中。在说明书中的各个位置出现该短语并不一定均是指相同的实施例，也不是与其它实施例互斥的独立的或备选的实施例。本领域技术人员显式地和隐式地理解的是，本文所描述的实施例可以与其它实施例相结合。在本文中提及的“实施方式”具有类似理解。
本领域技术人员可以理解，在各实施方式或实施例的方法中，各步骤的撰写顺序并不意味着严格的执行顺序而对实施过程构成任何限定，各步骤的详细执行顺序应当以其功能和可能的内在逻辑确定。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。
在本申请中，以“含有”、“包含”、“包括”等词语描述的开放式技术特征或技术方案中， 如无其他说明，不排除所列成员之外的额外成员，可视为既提供了由所列成员构成的封闭式特征或方案，还提供了在所列成员之外还包括额外成员的开放式特征或方案。例如，A包括a1、a2和a3，如无其他说明，可以还包括其他成员，也可以不包括额外成员，可视为既提供了“A由a1、a2和a3组成”的特征或方案，还提供了“A不仅包括a1、a2和a3，还包括其他成员”的特征或方案。
在本申请中，如无其他说明，A(如B)，表示B为A中的一种非限制性示例，可以理解A不限于为B。
在本申请中，“可选地”、“可选的”、“可选”，指可有可无，也即指选自“有”或“无”两种并列方案中的任一种。如果一个技术方案中出现多处“可选”，如无特别说明，且无矛盾之处或相互制约关系，则每项“可选”各自独立。
本申请一实施方式提供了一种复合集流体。复合集流体包括基材层、粘结层以及金属层。基材层具有相对的第一表面和第二表面。第一表面和第二表面两者中的至少一者上设有粘结层和金属层，粘结层位于基材层和金属层之间。金属层包括金属种子层和金属加厚层，金属种子层位于粘结层和金属加厚层之间。
在本实施方式的复合集流体中，通过粘结层的设置可以改善基材层和金属层之间的结合力，同时，金属加厚层在金属种子层之上设置，可以使金属层具有合适的厚度。因此，在本实施方式的复合集流体中，通过对集流体的结构进行设计，可以使金属层和基材层之间具有较好的结合力，同时使金属层具有较为合适的厚度。
请参阅图4，其中示出了本申请一实施方式中复合集流体3的结构。其中，复合集流体3包括基材层31、粘结层32以及金属层。基材层31具有相对的第一表面和第二表面。第一表面或第二表面上设有粘结层32和金属层，粘结层32位于基材层31和金属层之间。金属层包括金属种子层33和金属加厚层34，金属种子层33位于粘结层32和金属加厚层34之间。
请参阅图5，其中示出了本申请另一实施方式中复合集流体3的结构。其中，复合集流体3包括基材层31、粘结层32以及金属层。基材层31具有相对的第一表面和第二表面。第一表面和第二表面上均设有粘结层32和金属层，粘结层32位于基材层31和金属层之间。金属层包括金属种子层33和金属加厚层34，金属种子层33位于粘结层32和金属加厚层34之间。
可以理解的是，在复合集流体中，金属层的厚度降低可以在一定程度上减少复合集流体的整体厚度和制造成本。但是厚度较小的金属层可能会带来较大的内阻，因此需要使金属层 的厚度保持在较为合适的范围。同时，由于基材层与金属层的差异，一体式厚度较大的金属层难以与基材层之间形成较为稳定的结合力。在本实施方式中，通过粘结层、金属种子层以及金属加厚层的设置，可以使金属层具有较为合适的厚度，同时使基材层和金属层之间具有较好的结合力。
在一些实施方式中，粘结层包含熔点≥80摄氏度(℃)的聚合物。可选地，粘结层包含熔点为80℃～400℃的聚合物。聚合物的熔点在该范围内可以使粘结层保持良好的稳定性，降低制备金属种子层时，粘结层表面出现孔洞的风险，进一步提高金属种子层与粘结层之间的结合力。另外，孔洞的减少还可以降低极片中析锂的风险。进一步可选地，粘结层包含聚烯烃、乙烯-丙烯共聚物、乙烯-醋酸乙烯共聚物、乙烯-乙烯醇共聚物、聚氨酯、环氧树脂、苯乙烯-异戊二烯-苯乙烯共聚物、苯乙烯-丁二烯-苯乙烯共聚物、苯乙烯-乙烯-丁烯-苯乙烯共聚物、苯乙烯-乙烯-丙烯-苯乙烯共聚物、硅橡胶、酚醛树脂、脲醛树脂以及聚酰亚胺中的至少一种。进一步可选地，粘结层包含的聚合物的熔点可以是80℃、100℃、120℃、150℃、180℃、200℃、220℃、250℃、280℃、300℃、320℃、350℃、380℃、400℃等。
在一些实施方式中，粘结层的熔点大于基材层的熔点。此时，在制备金属种子层时不易在粘结层的表面形成孔洞，有利于进一步提高金属种子层与粘结层之间的结合力。
在一些实施方式中，粘结层的厚度为200纳米(nm)～1500nm。粘结层的厚度在该范围内可以在发挥较好粘结效果的基础上使复合集流体保持较为合适的整体厚度，降低复合集流体出现厚度过大的风险。可选地，粘结层的厚度可以是200nm、300nm、400nm、500nm、600nm、700nm、800nm、900nm、1000nm、1100nm、1200nm、1300nm、1400nm、1500nm等。进一步可选地，粘结层的厚度为300nm～700nm。
在一些实施方式中，金属种子层包括溅射金属种子层、蒸镀金属种子层以及喷涂金属种子层中的至少一种。可以理解的是，溅射金属种子层可以是通过诸如磁控溅射等溅射方式形成的金属种子层。蒸镀金属种子层可以是通过蒸镀方式形成的金属种子层。喷涂金属种子层可以是通过喷涂方式形成的金属种子层。溅射金属种子层、蒸镀金属种子层以及喷涂金属种子层可以与粘结层保持较好的粘结力，有利于提高复合集流体结构的整体稳定性。可选地，金属种子层包括喷涂金属种子层。喷涂金属种子层在形成过程中温度相对较低，可以减小制备金属种子层时对粘结层的影响，降低粘结层因为高温而出现孔洞的风险。
在一些实施方式中，金属种子层的厚度为1nm～200nm。该厚度范围内的金属种子层便于制备得到，且能够与粘结层保持较好的结合力。可选地，金属种子层可以通过溅射、蒸镀以 及喷涂中的至少一种方式制备。可选地，金属种子层的厚度可以是1nm、5nm、10nm、20nm、30nm、40nm、50nm、60nm、70nm、80nm、90nm、100nm、120nm、150nm、180nm等。进一步可选地，金属种子层的厚度为20nm～100nm。
在一些实施方式中，金属种子层包含铜、铜合金、铝以及铝合金中的至少一种。
在一些实施方式中，金属加厚层包括电镀金属加厚层。可以理解的是，电镀金属加厚层可以是通过电镀方式形成的金属加厚层。金属种子层具有较好的导电性，便于电镀形成金属加厚层。
在一些实施方式中，金属加厚层的厚度为0.2微米(μm)～2μm。金属加厚层的厚度在该范围内可以使金属层整体具有较为合适的厚度，使复合集流体兼顾较为合适的金属层厚度和内阻。可选地，金属加厚层的厚度可以是0.2μm、0.5μm、0.8μm、1μm、1.2μm、1.5μm、1.5μm、1.8μm、2μm等。进一步可选地，金属加厚层的厚度为0.5μm～1.5μm。
在一些实施方式中，基材层包含聚酰胺、聚酰亚胺、聚对苯二甲酸乙二醇酯、聚对苯二甲酸丁二醇酯、聚对苯二甲酰对苯二胺、聚乙烯、聚丙烯、聚丙乙烯、聚四氟乙烯、聚偏氟乙烯、聚苯乙烯、聚氯乙烯、丙烯腈-丁二烯-苯乙烯共聚物、聚甲醛、环氧树脂、酚醛树脂、硅橡胶以及聚碳酸酯中的至少一种。可选地，基材层的厚度为2μm～10μm。比如，基材层的厚度可以是2μm、3μm、4μm、5μm、6μm、7μm、8μm、9μm、10μm等。进一步可选地，基材层的厚度为3μm～8μm。
本申请还有一实施方式提供了一种复合集流体的制备方法。该复合集流体的制备方法包括如下步骤：提供基材层，基材层具有相对的第一表面和第二表面。在第一表面和/或第二表面依次制备粘结层、金属种子层和金属加厚层。
可选地，金属种子层通过溅射、蒸镀以及喷涂中的至少一种方式制备。金属加厚层通过电镀的方式制备。
在一些实施方式中，粘结层的制备方法包括：将包含粘结层的原料的浆料涂布在基材层的表面，然后熟化形成粘结层。
可选地，可以采用凹版涂布的方式涂布浆料。可选地，在浆料表面制备金属种子层，然后再熟化。这样一方面可以提高粘结层的表层硬度，另一方面还可以进一步提高金属种子层与粘结层之间的结合力。可选地，熟化的温度为80℃～90℃，熟化的时间为4秒(s)～8s。
进一步可选地，对熟化之后的产品进行辊压，以使金属种子层和粘结层充分粘附，并可以提高粘结层厚度的均匀性。
在一些实施方式中，复合集流体的制备方法包括如下步骤：在基材层的至少一个表面涂布包含粘结层的原料的浆料；在浆料表面制备金属种子层；对浆料进行熟化；对熟化后的产品进行辊压；辊压之后再次熟化；在熟化后的产品的金属种子层的表面制备金属加厚层。
可以理解的是，在基材的两个表面分别制备粘结层和金属种子层时，可以对基材层的两个表面分别进行操作，也可以对基材层的两个表面同时操作。
本申请还有一实施方式提供了一种极片。极片包括上述复合集流体和上述制备方法制备的复合集流体中的至少一种。
本申请还有一实施方式提供了一种二次电池。二次电池包括上述极片。
本申请还有一实施方式提供了一种用电装置。用电装置包括上述复合集流体、上述制备方法制备的复合集流体、上述极片以及上述二次电池中的至少一种。
以下适当参照附图对本申请的二次电池和用电装置进行说明。
通常情况下，二次电池包括正极极片、负极极片、电解质和隔离膜。在电池充放电过程中，活性离子在正极极片和负极极片之间往返嵌入和脱出。电解质在正极极片和负极极片之间起到传导离子的作用。隔离膜设置在正极极片和负极极片之间，主要起到防止正负极短路的作用，同时可以使离子通过。
正极极片
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材料。
作为非限制性示例，正极集流体具有在其自身厚度方向相对的两个表面，正极活性材料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。
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。复合集流体可采用上述复合集流体。复合集流体也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形成在高分子材料基材上而获得。所述正极集流体中，该金属材料的非限制性示例可以包括铝、铝合金、镍、镍合金、钛、钛合金、银及银合金等中的一种或多种。所述正极集流体中，该高分子材料基材的非限制性示例可以包括聚丙烯(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)等基材中的一种或多种。
在其中一些实施例中，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。作为非限制性示例，正极活性材料可包括以下材料中的一种或多种：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、锂锰氧化物、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、锂镍钴铝氧化物及其改性化合物等中的一种或多种。橄榄石结构的含锂磷酸盐的非限制性示例可包括但不限于磷酸铁锂、磷酸铁锂与碳的复合材料、磷酸锰锂、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一种或多种。锂钴氧化物的非限制性示例可以包括LiCoO2；锂镍氧化物的非限制性示例可以包括LiNiO2；锂锰氧化物的非限制性示例可以包括LiMnO2、LiMn2O4等；锂镍钴锰氧化物的非限制性示例可以包括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)等。锂镍钴铝氧化物的非限制性示例可以包括LiNi0.8Co0.15Al0.05O2。
在其中一些实施例中，正极活性材料层还可选地包括粘结剂。作为非限制性示例，粘结剂可以包括聚偏氟乙烯(PVDF)、聚四氟乙烯(PTFE)、偏氟乙烯-四氟乙烯-丙烯三元共聚物、偏氟乙烯-六氟丙烯-四氟乙烯三元共聚物、四氟乙烯-六氟丙烯共聚物及含氟丙烯酸酯树脂中的一种或多种。
在其中一些实施例中，正极活性材料层还可选地包括导电剂。作为非限制性示例，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一种或多种。
在其中一些实施例中，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中，形成正极浆料；将正极浆料涂覆在正极集流体的至少一侧表面上，经烘干、冷压等工序后，即可得到正极极片。溶剂的种类可以选自但不限于前述实施方式中的任一种，例如N-甲基吡咯烷酮(NMP)。正极浆料所涂覆的正极集流体表面可以为正极集流体的单个表面上，也可以为正极集流体的两个表面上。正极浆料所涂覆的正极集流体表面可以为正极集流体的单个表面上，也可以为正极集流体的两个表面上。正极浆料的固含量可以为40重量％(wt％)～80wt％。正极浆料在室温下的粘度可以调整到5000毫帕·秒(mPa·s)～25000mPa·s。涂覆正极浆料时，以干重计(扣除溶剂)的涂布单位面密度可以为15毫克/平方厘米(mg/cm2)～35mg/cm2。正极极片的压实密度可以为3.0克/立方厘米(g/cm3)～3.6g/cm3，可选为3.3g/cm3～3.5g/cm3。
负极极片
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活性材料层，负极活性材料层包括负极活性材料。
作为非限制性示例，负极集流体具有在其自身厚度方向相对的两个表面，负极活性材料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。
在其中一些实施例中，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。复合集流体可采用上述复合集流体。复合集流体也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形成在高分子材料基材上而获得。所述负极集流体中，该金属材料的非限制性示例可以包括铜、铜合金、镍、镍合金、钛、钛合金、银及银合金等中的一种或多种。所述负极集流体中，该高分子材料基材的非限制性示例可以包括聚丙烯(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)等基材中的一种或多种。
在其中一些实施例中，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。作为非限制性示例，负极活性材料可包括以下材料中的一种或多种：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。硅基材料可以包括单质硅、硅氧化合物、硅碳复合物、硅氮复合物以及硅合金中的一种或多种。锡基材料可以包括单质锡、锡氧化合物以及锡合金中的一种或多种。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。
在其中一些实施例中，负极活性材料层还可选地包括粘结剂。粘结剂可以包括丁苯橡胶(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)中的一种或多种。
在其中一些实施例中，负极活性材料层还可选地包括导电剂。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一种或多种。
在其中一些实施例中，负极活性材料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。
在其中一些实施例中，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(溶剂的非限制性示例如去离子水)中，形成负极浆料；将负极浆料涂覆在负极集流体的至少一侧表面上，经烘干、 冷压等工序后，即可得到负极极片。负极浆料所涂覆的负极集流体表面可以为负极集流体的单个表面上，也可以为负极集流体的两个表面上。负极浆料的固含量可以为40wt％～60wt％。负极浆料在室温下的粘度可以调整到2000mPa·s～10000mPa·s。涂覆负极浆料时，以干重计(扣除溶剂)的涂布单位面密度可以为75克/平方米(g/m2)～220g/m2。负极极片的压实密度可以为1.0g/cm3～1.8g/cm3。
电解质
电解质具有在正极极片和负极极片之间传导离子的作用。本申请对电解质的种类没有特别的限制，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。
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。
在其中一些实施例中，电解质盐可以包括六氟磷酸锂(LiPF6)、四氟硼酸锂(LiBF4)、高氯酸锂(LiClO4)、六氟砷酸锂(LiAsF6)、双氟磺酰亚胺锂(LiFSI)、双三氟甲磺酰亚胺锂(LiTFSI)、三氟甲磺酸锂(LiTFS)、二氟磷酸锂(LiPO2F2)、二氟草酸硼酸锂(LiDFOB)、二草酸硼酸锂(LiBOB)、二氟二草酸磷酸锂(LiDFOP)及四氟草酸磷酸锂(LiTFOP)中的一种或多种。
在其中一些实施例中，溶剂可以包括碳酸乙烯酯(EC，)、碳酸丙烯酯(PC，)、碳酸甲乙酯(EMC)、碳酸二乙酯(DEC)、碳酸二甲酯(DMC)、碳酸二丙酯(DPC)、碳酸甲丙酯(MPC)、碳酸乙丙酯(EPC)、碳酸丁烯酯氟代碳酸乙烯酯(FEC)、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一种或多种。
在其中一些实施例中，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。
在一些实施方式中，电解液中的添加剂可以包括但不限于氟代碳酸乙烯酯(FEC)、二氟碳酸乙烯酯(DFEC)、三氟甲基碳酸乙烯酯(TFPC)等中的一种或多种。
隔离膜
在其中一些实施例中，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。
在其中一些实施例中，隔离膜的材质可以包括玻璃纤维、无纺布、聚乙烯、聚丙烯及聚偏二氟乙烯中的一种或多种。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。
在一些实施方式中，所述隔离膜的厚度为6μm～40μm，可选为12μm～20μm。
在其中一些实施例中，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。
在其中一些实施例中，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。
在其中一些实施例中，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，进一步地，塑料的非限制性示例可以包括聚丙烯、聚对苯二甲酸丁二醇酯以及聚丁二酸丁二醇酯等中的一种或多种。
二次电池中包括至少一个电池单体。二次电池可以包括1个或多个电池单体。
在本申请中，如无其他说明，“电池单体”指能够实现化学能和电能相互转化的基本单元，进一步地，通常而言至少包括正极极片、负极极片和电解质。在电池充放电过程中，活性离子在正极极片和负极极片之间往返嵌入和脱出。电解质在正极极片和负极极片之间起到传导活性离子的作用。
本申请对电池单体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1是作为一个示例的方形结构的电池单体1。
在其中一些实施例中，参照图2，外包装可包括壳体11和盖板13。其中，壳体11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11具有与容纳腔连通的开口，盖板13能够盖设于开口，以封闭容纳腔。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12。电极组件12封装于容纳腔内。电解液浸润于电极组件12中。电池单体1所含电极组件12的数量可以为一个或多个，本领域技术人员可根据实际需求进行选择。
二次电池可以为电池模块或电池包。
电池模块包括至少一个电池单体。电池模块所含电池单体的数量可以为一个或多个，本领域技术人员可根据电池模块的应用和容量选择合适的数量。
在电池模块中，多个电池单体可以是沿电池模块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电池单体进行固定。
可选地，电池模块还可以包括具有容纳空间的外壳，多个电池单体容纳于该容纳空间。
在其中一些实施例中，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，本领域技术人员可根据电池包的应用和容量选择合适的数量。
在电池包中可以包括电池箱和设置于电池箱中的多个电池模块。电池箱包括上箱体和下箱体，上箱体能够盖设于下箱体，并形成用于容纳电池模块的封闭空间。多个电池模块可以按照任意的方式排布于电池箱中。
另外，本申请还提供一种用电装置，用电装置包括本申请提供的二次电池。二次电池可以用作用电装置的电源，也可以用作用电装置的能量存储单元。用电装置可以包括移动设备、电动车辆、电气列车、船舶及卫星、储能系统等，但不限于此。其中，移动设备例如可以是手机、笔记本电脑等；电动车辆例如可以是纯电动车、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，但不限于此。
作为用电装置，可以根据其使用需求来选择二次电池。
图3是作为一个示例的用电装置2。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。
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。
实施例
为了使本申请所解决的技术问题、技术方案及有益效果更加清楚，以下将结合实施例和附图对本申请进行进一步详细说明。显然，所描述的实施例仅仅是本申请一部分实施例，而不是全部的实施例。以下对至少一个示例性实施例的描述实际上仅仅是说明性的，决不作为对本申请及其应用的任何限制。基于本申请中的实施例，本领域普通技术人员在没有付出创造性劳动前提下所获得的所有其他实施例都属于本申请保护的范围。
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。
实施例1
本实施例中复合集流体的制备方法包括如下步骤：
S101：在基材层的一个表面采用凹版涂布包含粘结层的原料的浆料。
S102：在浆料的表面采用磁控溅射的方式制备金属种子层。
S103：将S102得到的产品在80℃～90℃下烘烤4s～8s，对浆料进行熟化以形成粘结层。
S104：对S103得到的产品进行辊压处理。
S105：对辊压处理之后的产品进行再次熟化，熟化温度85℃，熟化时间72小时(h)。
S106：在S105得到的产品的金属种子层的表面电镀制备金属加厚层。电镀的速度为4米/分钟(m/min)～8m/min。电镀之后得到本实施例中的复合集流体。
实施例2
本实施例中复合集流体的制备方法包括如下步骤：
S101：在基材层的一个表面采用凹版涂布包含粘结层的原料的浆料。
S102：在浆料的表面采用磁控溅射的方式制备金属种子层。
S103：将S102得到的产品在80℃～90℃下烘烤4s～8s，对浆料进行熟化以形成粘结层。
S104：对S103得到的产品进行辊压处理。
S105：在基材层的另一个表面采用凹版涂布包含粘结层的原料的浆料。
S106：在浆料的表面采用磁控溅射的方式制备金属种子层。
S107：将S106得到的产品在80℃～90℃下烘烤4s～8s，对浆料进行熟化以形成粘结层。
S108：对S107得到的产品进行辊压处理。
S109：对辊压处理之后的产品进行再次熟化，熟化温度85℃，熟化时间72h。
S110：在S109得到的产品的两个金属种子层的表面同时电镀制备金属加厚层。电镀的速度为4m/min～8m/min。电镀之后得到本实施例中的复合集流体。
实施例3～实施例18
与实施例2相比，实施例3～实施例18的不同之处在于基材层的材料、基材层的厚度、粘结层的材料、粘结层的厚度、金属种子层的材料、金属种子层的制备方式、金属种子层的厚度、金属加厚层的厚度等有所不同。具体如表1中所示。
对比例1～对比例3
与实施例2相比，对比例1～对比例3的不同之处在于，复合集流体不包括粘结层，且基材层的材料有所不同。
测试例
(1)金属层剥离强度测试：将样品与EAA薄膜非电晕面贴合后，再将12μmPET覆盖在EAA薄膜上，将其放在热封机上，温度120℃，压力0.2兆帕(Mpa)进行贴合。将贴合后得样品裁切成长100mm，宽20mm的样品，用3M双面胶将金属层未贴合面贴在钢板上；将样品夹在拉力机的夹具上，间距50mm，速度300毫米/分钟(mm/min)进行180℃剥离试验，读取剥离力大小换算成牛/米(N/m)单位，平行样5条，最终取剥离力平均值。
(2)复合集流体孔洞测试：用在线CCD高速相机测试1000米(m)长度复合集流体孔洞数量，然后除以测试段集流体的面积，计算得出每平方米孔洞数量。
(3)复合集流体方阻测试：使用四探针方阻测试仪对样品金属层大面进行方阻测试，随机测试30个点，取30个点方阻平均值。
表1

表1中，基材层厚度的单位为μm。熔点表示粘结层包含的聚合物的熔点，单位为℃。粘结层厚度的单位为nm。金属种子层厚度的单位为nm。金属加厚层厚度的单位为μm。金属层剥离强度的单位为N/m。孔洞数量的单位为个/平方米(个/m2)。方阻的单位为毫欧每平方(mΩ/□)。
由实施例1～实施例18和对比例1～对比例3可以看出，在基材层和金属层之间引入粘结层可以提高金属层的剥离强度。
由实施例11～实施例16可以看出，喷涂制备金属种子层时，可以减小复合集流体的孔洞数量，尤其是可以减少直径≤100μm的孔洞数量。
以上所述实施例的各技术特征可以进行任意的组合，为使描述简洁，未对上述实施例中的各个技术特征所有可能的组合都进行描述，然而，只要这些技术特征的组合不存在矛盾，都应当认为是本说明书记载的范围。
以上所述实施例仅表达了本申请的几种实施方式，其描述较为具体和详细，但并不能因此而理解为对发明专利范围的限制。应当指出的是，对于本领域的普通技术人员来说，在不 脱离本申请构思的前提下，还可以做出若干变形和改进，这些都属于本申请的保护范围。因此，本申请专利的保护范围应以所附权利要求为准。

Claims (22)

  1. 一种复合集流体，包括基材层、粘结层以及金属层；所述基材层具有相对的第一表面和第二表面；所述第一表面和所述第二表面两者中的至少一者上设有所述粘结层和所述金属层，所述粘结层位于所述基材层和所述金属层之间；所述金属层包括金属种子层和金属加厚层，所述金属种子层位于所述粘结层和所述金属加厚层之间。
  2. 根据权利要求1所述的复合集流体，其中，所述粘结层包含熔点≥80℃的聚合物。
  3. 根据权利要求1或2所述的复合集流体，其中，所述粘结层包含熔点为80℃～400℃的聚合物。
  4. 根据权利要求1～3中任一项所述的复合集流体，其中，所述粘结层包含聚烯烃、乙烯-丙烯共聚物、乙烯-醋酸乙烯共聚物、乙烯-乙烯醇共聚物、聚氨酯、环氧树脂、苯乙烯-异戊二烯-苯乙烯共聚物、苯乙烯-丁二烯-苯乙烯共聚物、苯乙烯-乙烯-丁烯-苯乙烯共聚物、苯乙烯-乙烯-丙烯-苯乙烯共聚物、硅橡胶、酚醛树脂、脲醛树脂以及聚酰亚胺中的至少一种。
  5. 根据权利要求1～4中任一项所述的复合集流体，其中，所述粘结层的厚度为200nm～1500nm。
  6. 根据权利要求1～5中任一项所述的复合集流体，其中，所述粘结层的厚度为300nm～700nm。
  7. 根据权利要求1～6中任一项所述的复合集流体，其中，所述金属种子层包括溅射金属种子层、蒸镀金属种子层以及喷涂金属种子层中的至少一种。
  8. 根据权利要求1～7中任一项所述的复合集流体，其中，所述金属种子层的厚度为1nm～200nm。
  9. 根据权利要求1～8中任一项所述的复合集流体，其中，所述金属种子层的厚度为20nm～100nm。
  10. 根据权利要求1～9中任一项所述的复合集流体，其中，所述金属种子层包含铜、铜合金、铝以及铝合金中的至少一种。
  11. 根据权利要求1～10中任一项所述的复合集流体，其中，所述金属加厚层包括电镀金属加厚层。
  12. 根据权利要求1～11中任一项所述的复合集流体，其中，所述金属加厚层的厚度为0.2μm～2μm。
  13. 根据权利要求1～12中任一项所述的复合集流体，其中，所述金属加厚层的厚度为0.5μm～1.5μm。
  14. 根据权利要求1～13中任一项所述的复合集流体，其中，所述基材层包含聚酰胺、聚酰亚胺、聚对苯二甲酸乙二醇酯、聚对苯二甲酸丁二醇酯、聚对苯二甲酰对苯二胺、聚乙烯、聚丙烯、聚丙乙烯、聚四氟乙烯、聚偏氟乙烯、聚苯乙烯、聚氯乙烯、丙烯腈-丁二烯-苯乙烯共聚物、聚甲醛、环氧树脂、酚醛树脂、硅橡胶以及聚碳酸酯中的至少一种。
  15. 根据权利要求1～14中任一项所述的复合集流体，其中，所述基材层的厚度为2μm～10μm。
  16. 根据权利要求1～15中任一项所述的复合集流体，其中，所述基材层的厚度为3μm～8μm。
  17. 一种复合集流体的制备方法，包括如下步骤：
    提供基材层，所述基材层具有相对的第一表面和第二表面；
    在所述第一表面和/或所述第二表面依次制备粘结层、金属种子层和金属加厚层。
  18. 根据权利要求17所述的制备方法，其中，所述金属种子层通过溅射、蒸镀以及喷涂中的至少一种方式制备。
  19. 根据权利要求17或18所述的制备方法，其中，所述金属加厚层通过电镀的方式制备。
  20. 一种极片，其中，包括权利要求1～16中任一项所述的复合集流体和权利要求17～19中任一项所述的制备方法制备的复合集流体中的至少一种。
  21. 一种二次电池，包括权利要求20所述的极片。
  22. 一种用电装置，包括权利要求1～16中任一项所述的复合集流体、权利要求17～19中任一项所述的制备方法制备的复合集流体、权利要求20所述的极片以及权利要求21所述的二次电池中的至少一种。
PCT/CN2024/114336 2023-11-27 2024-08-23 复合集流体、极片、二次电池以及用电装置 Pending WO2025112709A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202311601267.1 2023-11-27
CN202311601267.1A CN120048915A (zh) 2023-11-27 2023-11-27 复合集流体、极片、二次电池以及用电装置

Publications (1)

Publication Number Publication Date
WO2025112709A1 true WO2025112709A1 (zh) 2025-06-05

Family

ID=95746875

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2024/114336 Pending WO2025112709A1 (zh) 2023-11-27 2024-08-23 复合集流体、极片、二次电池以及用电装置

Country Status (2)

Country Link
CN (1) CN120048915A (zh)
WO (1) WO2025112709A1 (zh)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111900413A (zh) * 2020-08-11 2020-11-06 珠海冠宇电池股份有限公司 一种集流体及其制备方法和应用
CN113707886A (zh) * 2021-06-16 2021-11-26 浙江柔震科技有限公司 一种多功能复合集流体及其制备方法
CN217009233U (zh) * 2022-03-03 2022-07-19 福建金石能源有限公司 一种锂电池复合集流体
CN218939731U (zh) * 2022-11-16 2023-04-28 浙江鑫柔科技有限公司 一种耐腐蚀柔性集流体
CN116895761A (zh) * 2023-06-21 2023-10-17 合肥源元科技股份有限公司 一种具有梯度多层结构金属层的柔性复合正极集流体及其制备方法
WO2023206689A1 (zh) * 2022-04-29 2023-11-02 扬州纳力新材料科技有限公司 集流体及其制备方法和应用

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111900413A (zh) * 2020-08-11 2020-11-06 珠海冠宇电池股份有限公司 一种集流体及其制备方法和应用
CN113707886A (zh) * 2021-06-16 2021-11-26 浙江柔震科技有限公司 一种多功能复合集流体及其制备方法
CN217009233U (zh) * 2022-03-03 2022-07-19 福建金石能源有限公司 一种锂电池复合集流体
WO2023206689A1 (zh) * 2022-04-29 2023-11-02 扬州纳力新材料科技有限公司 集流体及其制备方法和应用
CN218939731U (zh) * 2022-11-16 2023-04-28 浙江鑫柔科技有限公司 一种耐腐蚀柔性集流体
CN116895761A (zh) * 2023-06-21 2023-10-17 合肥源元科技股份有限公司 一种具有梯度多层结构金属层的柔性复合正极集流体及其制备方法

Also Published As

Publication number Publication date
CN120048915A (zh) 2025-05-27

Similar Documents

Publication Publication Date Title
CN113097441B (zh) 电化学装置及电子装置
WO2025077083A1 (zh) 负极极片、二次电池以及用电装置
WO2023060529A1 (zh) 锂离子电池
WO2025020400A1 (zh) 电极组件、电池和用电设备
CN115832184A (zh) 无锂负极极片及其制备方法、二次电池、电池模块、电池包及用电装置
CN116964766A (zh) 正极极片、二次电池、电池模块、电池包和用电装置
WO2025200884A1 (zh) 二次电池及用电装置
WO2025055185A1 (zh) 隔离膜及其制备方法、电池和用电装置
CN121100411A (zh) 电池和用电装置
WO2023070992A1 (zh) 电化学装置及包括其的电子装置
WO2023130204A1 (zh) 二次电池、电池模块、电池包和用电装置
CN115336068A (zh) 电化学装置及包括其的电子装置
CN219591429U (zh) 阴极极片、电极组件、电芯、电池单体、电池和用电装置
WO2025112299A1 (zh) 复合集流体、极片、二次电池和用电装置
WO2025112489A1 (zh) 负极极片、二次电池以及用电装置
WO2024169401A1 (zh) 负极极片及其制备方法、电池和用电装置
WO2024164109A1 (zh) 预锂化电极材料及其制备方法、二次电池和用电装置
WO2025112709A1 (zh) 复合集流体、极片、二次电池以及用电装置
WO2023184098A1 (zh) 含硅负极活性材料、以及包含其的负极极片、二次电池及用电装置
WO2025107779A1 (zh) 复合集流体、极片、二次电池和用电装置
WO2025112292A1 (zh) 正极复合集流体、正极极片、二次电池和用电装置
WO2025112715A9 (zh) 复合集流体及其制备方法、电极极片、电池和用电装置
WO2025112298A9 (zh) 复合集流体、极片、二次电池和用电装置
KR20260055479A (ko) 복합 집전체, 극판, 이차전지 및 전기기기
WO2024082280A1 (zh) 集流体、二次电池以及用电装置

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 24895810

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 1020267008966

Country of ref document: KR