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CN-121976272-A - High-compactness functional current collector and preparation method and application thereof

CN121976272ACN 121976272 ACN121976272 ACN 121976272ACN-121976272-A

Abstract

The invention discloses a high-compactness functional current collector, a preparation method and application thereof, and relates to the technical field of current collectors. The invention prepares the high-compactness functional current collector by magnetron sputtering copper plating on the surface of the PET base film and matching with a pulse plating process, the conductive seed layer obtained by magnetron sputtering and the thickened copper layer obtained by pulse plating are controlled to be single-oriented in the growth process of crystal grains on the surface of the base material, the compactness of the functional copper foil is optimized, the conductivity is improved, the product performance is optimized, the surface tension of the electroplating solution is reduced by adding the surfactant into the electroplating solution under the condition that the performance of the high-compactness functional current collector is not influenced, the surface of a cathode is easier to be wetted by the solution, the interface defect of a plating layer is reduced, and the compactness, the copper plating rate and the uniformity of the copper layer are improved by adding the composite additive into the electroplating solution.

Inventors

  • YIN YIN
  • LI XUEFA

Assignees

  • 扬州纳力新材料科技股份有限公司

Dates

Publication Date
20260505
Application Date
20260206

Claims (10)

  1. 1. A preparation method of a high-compactness functional current collector is characterized by comprising the following steps: s1, taking a copper target, performing surface treatment, and performing magnetron sputtering copper plating on the upper surface and the lower surface of a base film to obtain a conductive seed layer; S2, immersing the conductive seed layer in citric acid for 20-30S to obtain a pretreated seed layer; And S3, preparing electroplating solution, immersing the pretreated seed layer into the electroplating solution added with the composite additive, plating copper by adopting pulse electroplating to form a thickened copper layer, and washing and drying to obtain the high-compactness functional current collector.
  2. 2. The method for preparing the high-compactness functional current collector as claimed in claim 1, wherein the magnetron sputtering process is characterized in that sputtering power is 6-10 KW, vacuum degree is 0.003-0.005 Pa, argon flow is 130-150 sccm, cooling temperature of a sputtering main roller is-35-0 ℃, copper target power is 8-12 KW, and winding speed is 5-8 m/min.
  3. 3. The method for preparing the high-compactness functional current collector as claimed in claim 1, wherein the pulse plating process is carried out at a plating temperature of 30-40 ℃, a plating linear speed of 3-5 m/min, a pulse current density of 2-10A/dm 2 and a pulse frequency of 0.2-1 Hz.
  4. 4. The method for preparing the high-compactness functional current collector as claimed in claim 1, wherein the electroplating solution comprises the following components, by mass, 80-130 g/L copper sulfate, 80-160 g/L sulfuric acid, 50-60ppm chloride ions, and the balance of water.
  5. 5. The method for preparing the high-compactness functional current collector as claimed in claim 1, wherein the concentration of the composite additive in the electroplating solution is 200-300 mg/L.
  6. 6. The method for preparing a high-compactness functional current collector as claimed in claim 5, wherein the composite additive is prepared by the following process: Dissolving maleic anhydride in N-methyl pyrrolidone, adding 6-mercaptopurine, heating for reaction, filtering and drying to obtain a monomer compound; adding N-methyl pyrrolidone and hydroxyethyl acrylate into a reaction kettle, heating for reaction, adding a monomer compound, slowly dropwise adding an ammonium persulfate solution, reacting at constant temperature, cooling to room temperature, washing, filtering and drying to obtain a copolymer; And thirdly, mixing the copolymer and the sodium polydithio-dipropyl sulfonate, adding polyether, heating, and dispersing in high shear to obtain the composite additive.
  7. 7. The preparation method of the high-compactness functional current collector as claimed in claim 6, wherein the mass ratio of maleic anhydride to N-methylpyrrolidone to 6-mercaptopurine is 1:10-20:1-3.
  8. 8. The method for preparing the high-compactness functional current collector as claimed in claim 6, wherein the mass ratio of N-methyl pyrrolidone, hydroxyethyl acrylate, a monomer compound and ammonium persulfate is (10-20) to 1:1 to (0.5-2).
  9. 9. The method for preparing a high-compactness functional current collector as claimed in claim 6, wherein the mass ratio of the copolymer to the sodium polydithio-dipropyl sulfonate to the polyether is 1:0.1-0.5:0.1-0.5.
  10. 10. The use of a high-density functional current collector prepared by the preparation method according to any one of claims 1-9, characterized by the use in the preparation of lithium battery materials.

Description

High-compactness functional current collector and preparation method and application thereof Technical Field The invention relates to the technical field of current collectors, in particular to a high-compactness functional current collector, and a preparation method and application thereof. Background The current collector is a key component for bearing current collection and transmission functions in the lithium ion battery, and has the core functions of providing an electron transmission channel for positive and negative active substances and supporting the distribution of the active substances, and is generally composed of high-conductivity metal foils (such as copper foil and aluminum foil). The copper foil and aluminum foil current collector used in most current methods has higher cost and quality, is unfavorable for the control of battery cost and the improvement of energy density, and compared with the traditional foil, the sandwich structure of the functional foil has obvious advantages, wherein the inner layer is a polymer layer, and the two sides are metal layers. A compact and fine magnetic control copper seed layer is formed on a traditional functional current collector through magnetic control sputtering, and then a thickened copper layer is electroplated. Copper ions are randomly deposited on the magnetron copper seed layer to form an electroplated copper transition layer with random copper grain orientation at the beginning of electroplating, and then copper grains with the same orientation are continuously deposited on the electroplated copper transition layer to form a thickened copper layer, but the copper grains in the thickened copper layer are randomly oriented due to the fact that the copper grains in the electroplated copper transition layer grow along the copper grain direction in the electroplated copper transition layer in an epitaxial mode, irregular dislocation is serious in arrangement of interface grain boundaries among the grains, defect holes are extremely easy to form, and therefore compactness of the functional current collector is poor, and sheet resistance and tensile strength of the functional current collector are greatly reduced. Therefore, the invention provides a high-compactness functional current collector, and a preparation method and application thereof, so as to solve the technical problems. Disclosure of Invention The invention aims to provide a high-compactness functional current collector as well as a preparation method and application thereof, so as to solve the problems in the prior art. In order to achieve the above purpose, the present invention provides the following technical solutions: The high-compactness functional current collector comprises a base film and copper layers arranged on the upper surface and the lower surface of the base film, wherein the copper layers are composed of a conductive seed layer and a thickened copper layer, and the conductive seed layer is positioned between the base film and the thickened copper layer. Further, the thickness of the conductive seed layer is 40-100 nm. Further, the thickness of the thickened copper layer is 0.5-5 μm. Further, the base film is a PET film. Further, the thickness of the base film is 4-6 μm. A preparation method of a high-compactness functional current collector comprises the following steps: s1, taking a copper target, performing surface treatment, and performing magnetron sputtering copper plating on the upper surface and the lower surface of a base film to obtain a conductive seed layer; S2, immersing the conductive seed layer in citric acid for 20-30S to obtain a pretreated seed layer; And S3, preparing electroplating solution, immersing the pretreated seed layer into the electroplating solution added with the composite additive, plating copper by adopting pulse electroplating to form a thickened copper layer, and washing and drying to obtain the high-compactness functional current collector. Further, the electroplating solution comprises the following components, by mass, 80-130 g/L of copper sulfate, 80-160 g/L of sulfuric acid, 50-60ppm of chloride ions, and the balance of water. Further, in the step S1, the specific process of the surface treatment is that 70-80 vt% acetone solution is adopted for 3-4 times, and nitrogen is used for purging for 10-20 min at the pressure of 0.3-0.5 MPa. Further, the magnetron sputtering process conditions are that the sputtering power is 6-10 KW, the vacuum degree is 0.003-0.005 Pa, the argon flow is 130-150 sccm, the cooling temperature of a sputtering main roller is-35-0 ℃, the copper target power is 8-12 KW, and the winding speed is 5-8 m/min. Further, the concentration of the citric acid solution is 0.5-2 mol/L. Further, the process conditions of the pulse plating are that the plating temperature is 30-40 ℃, the plating linear speed is 3-5 m/min, the pulse current density is 2-10A/dm 2, the pulse frequency is 0.2-1 Hz, the plating period is 4-6 s, t