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CN-121986391-A - Composite current collector for lithium battery, equipment for preparing composite current collector and method for preparing composite current collector of lithium battery

CN121986391ACN 121986391 ACN121986391 ACN 121986391ACN-121986391-A

Abstract

A composite current collector for a lithium battery, an apparatus for preparing the composite current collector, and a method of preparing the composite current collector for a lithium battery. The composite current collector includes a base film, an intermediate layer, and a metal layer. The intermediate layer comprises composite particles comprising an electrically conductive core and a thermoplastic cladding. The inner core is distributed on the base film in a full-wrapping or half-wrapping way by the wrapping layer so as to improve the mechanical strength of the composite current collector and enable the composite current collector not to be easily deformed by thermal shrinkage. The equipment comprises a conveying assembly, a spraying device and a coating assembly. The conveying component is used for conveying the base film. The spraying device is used for spraying the composite particles to form an intermediate layer on the base film. The coating component is used for forming a metal layer on the intermediate layer.

Inventors

  • SHEN XUEZHONG
  • GUO BEI

Assignees

  • 纳狮新材料股份有限公司
  • 东莞瀚晶纳米材料有限公司

Dates

Publication Date
20260505
Application Date
20231229

Claims (18)

  1. A composite current collector for a lithium battery, comprising: a base film, an intermediate layer, and a metal layer formed over the intermediate layer; The middle layer comprises composite particles, the composite particles comprise an inner core with conductivity and a coating layer with thermoplasticity, and the inner core is fully or semi-coated by the coating layer and distributed on the base film so as to improve the mechanical strength of the composite current collector, so that the composite current collector is not easy to be deformed by thermal shrinkage.
  2. The composite current collector of claim 1, wherein the composite current collector has an elongation at break in the range of 31.2% to 48.2%.
  3. The composite current collector of claim 1, wherein the peel strength of the composite current collector is in the range of 6.8-9.3N/cm.
  4. The composite current collector of claim 1, wherein the tensile strength of the composite current collector is in the range of 182-233 MPa.
  5. The composite current collector of claim 1 wherein said coating comprises any one or more of polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyamide, polyoxymethylene, polycarbonate, polyphenylene oxide, polysulfone, polyethylene terephthalate.
  6. The composite current collector of claim 5 wherein said cladding layer further comprises graphene.
  7. The composite current collector of claim 1, wherein the thickness of the cladding layer is in the range of less than 10 nm.
  8. The composite current collector of claim 7, wherein the thickness of the cladding layer is in the range of 6-8 nm.
  9. The composite current collector of claim 1 wherein said inner core comprises at least one of aluminum, copper, nickel, tin, zinc, chromium, iron, lithium, cobalt and oxides or alloys thereof.
  10. The composite current collector of claim 1 wherein the ratio of metal to metal oxide in the core is 1:1.
  11. The composite current collector of claim 1, wherein the diameter of the inner core is in the range of 0-100 nm.
  12. An apparatus for preparing a composite current collector, comprising: a transfer assembly for transferring the base film; A spraying device for spraying the composite particles to form an intermediate layer on the base film, and And the coating assembly is used for forming a metal layer on the intermediate layer.
  13. The apparatus of claim 12, wherein the spraying device comprises: A cavity; An air intake duct extending from one end of the cavity into the cavity; a feed port extending from one side of the cavity into the cavity; The nozzle is connected with the air inlet pipeline and the feed inlet in the cavity and extends to the other end of the cavity; Wherein the gas inlet conduit is configured to pass a carrier gas to the nozzle, the feed inlet is configured to pass the composite particles to the nozzle, the composite particles being sprayed from the nozzle to the base film by the carrier gas.
  14. The apparatus of claim 13, wherein the spray device further comprises: An auxiliary air inlet pipe connected to a discharge port adjacent to the nozzle and configured to introduce the carrier gas to change the angle at which the composite particles leave the discharge port.
  15. The apparatus of claim 12, wherein the angle between the outlet of the nozzle and the surface of the base film to be coated is in the range of 0 to 90 degrees.
  16. The apparatus of claim 15, wherein the nozzle outlet is at an angle of 45 degrees to the surface of the base film to be coated.
  17. The apparatus of claim 12 wherein the nozzle discharge orifice is spaced from the base film by a distance of between 100 and 300 millimeters, the spray flow is 3000sccm, and the spray power is in the range of 0 to 200 KW.
  18. A method of preparing a lithium battery composite current collector, comprising: forming an intermediate layer on a base film, the intermediate layer comprising composite particles comprising an electrically conductive core and a thermoplastic coating, the core being fully or semi-encased by the coating and being disposed on the base film, and A metal layer is formed over the composite particle layer.

Description

Composite current collector for lithium battery, equipment for preparing composite current collector and method for preparing composite current collector of lithium battery Technical Field The invention belongs to the field of lithium battery composite current collectors, and particularly relates to a composite current collector for a lithium battery, equipment for preparing the composite current collector and a method for preparing the lithium battery composite current collector. Background Along with the continuous growth of new energy automobile industry, the demand of lithium ion batteries also rises rapidly, and a current collector is used as one of indispensable component parts in the lithium ion batteries, so that the current collector not only can bear active substances, but also can collect and output current generated by electrode active substances. The composite current collector is a three-layer composite structure of metal-high polymer material-metal formed by stacking metal atoms on two sides of a composite material by taking a raw material film such as PET/PP as a base film through a vacuum coating process and the like. At present, common vacuum preparation modes are basically one or combination of magnetron sputtering and evaporation coating, after a nm-level priming layer is formed on the surface of the magnetron sputtering, a metal layer is thickened by adopting a vacuum evaporation method and the like, and in the process, how to ensure good adhesion between a base film and a coating layer is a key for the subsequent stable operation of a composite current collector. Disclosure of Invention In view of the above, the present application proposes a composite current collector for a lithium battery, an apparatus for preparing the composite current collector, and a method of preparing the composite current collector for a lithium battery to solve the above problems. According to an embodiment of the present application, a composite current collector for a lithium battery is provided. The composite current collector includes a base film, an intermediate layer, and a metal layer formed over the intermediate layer. The intermediate layer includes composite particles. The composite particles include an electrically conductive core and a thermoplastic cladding. The inner core is distributed on the base film in a full-wrapping or half-wrapping mode by the wrapping layer so as to improve the mechanical strength of the composite current collector, and the composite current collector is not easy to be subjected to thermal shrinkage deformation. In certain embodiments, the elongation at break of the composite current collector is in the range of 31.2% -48.2%. In certain embodiments, the composite current collector has a peel strength in the range of 6.8-9.3N/cm. In certain embodiments, the tensile strength of the composite current collector is in the range of 182-233 MPa. In certain embodiments, the coating comprises any one or more of polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyamide, polyoxymethylene, polycarbonate, polyphenylene oxide, polysulfone, polyethylene terephthalate. In certain embodiments, the coating further comprises graphene. In certain embodiments, the thickness of the cladding layer is in the range of less than 10 nm. In certain embodiments, the thickness of the cladding layer is in the range of 6-8 nm. In certain embodiments, the inner core comprises at least one of aluminum, copper, nickel, tin, zinc, chromium, iron, lithium, cobalt, oxides or alloys thereof, and the like. In certain embodiments, the ratio of metal to metal oxide in the core is 1:1. In certain embodiments, the diameter of the inner core is in the range of 0-100 nm. According to an embodiment of the present application, an apparatus for preparing a composite current collector is provided. The equipment comprises a conveying assembly, a spraying device and a coating assembly. The conveying component is used for conveying the base film. The spraying device is used for spraying composite particles to form an intermediate layer on the base film. The coating component is used for forming a metal layer on the intermediate layer. In certain embodiments, the spray device includes a chamber, an air inlet conduit, a feed inlet, and a nozzle. The air inlet pipe extends from one end of the cavity into the cavity. The nozzle is connected with the air inlet pipeline and the feed inlet in the cavity and extends towards the other end of the cavity. The gas inlet conduit is configured to pass a carrier gas to the nozzle, and the feed port is configured to pass the composite particles to the nozzle. The composite particles are sprayed from the nozzle toward the base film by the carrier gas. In some embodiments, the spray coating device further comprises an auxiliary air inlet pipe. The auxiliary air inlet pipe is connected to a discharge port adjacent to the nozzle. The auxiliary air inlet pipe is configured to in