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CN-121976279-A - Micro-pore copper foil etching method

CN121976279ACN 121976279 ACN121976279 ACN 121976279ACN-121976279-A

Abstract

The invention relates to a microporous copper foil etching method, which comprises the steps of (1) copper foil substrate surface pretreatment, (2) etching solution configuration, (3) electrochemical etching and (4) post-treatment. In the invention, the main etchant provides etching driving force, the hole structure regulator regulates and controls the selectivity of etching sites through adsorption, the conductive medium promotes the conductivity of etching liquid, and chloride ions cooperatively control the growth direction and the aperture uniformity of holes. The pore diameter of the prepared microporous copper foil is uniformly distributed in the range of 0.1-200 mu m, the porosity can be flexibly regulated and controlled within the range of 0.05-40%, and the requirements of different battery systems on pore structures are met.

Inventors

  • Chu Changshun
  • MA XIANG
  • YANG TAO
  • JIANG YANG

Assignees

  • 九江德福科技股份有限公司

Dates

Publication Date
20260505
Application Date
20260113

Claims (10)

  1. 1. The micro-pore copper foil etching method is characterized by comprising the following steps of: (1) Using electrolytic copper foil as a base material, and carrying out oil removal and acid washing treatment on the surface of the base material; (2) Preparing an aqueous solution containing a main etchant, a pore structure regulator, a conductive medium and chloride ions as etching liquid; (3) Performing electrochemical etching by using the electrolytic copper foil in the step (1) as an anode by adopting direct current electroplating, and forming uniform micropores on the surface of the electrolytic copper foil; (4) And (5) cleaning, performing anti-oxidation treatment, and drying to obtain the microporous copper foil.
  2. 2. The method for etching the microporous copper foil according to claim 1, wherein the main etchant in the step (2) is one or more of sulfuric acid, nitric acid, sodium chlorate, sodium hypochlorite, sodium perchlorate, sodium persulfate and ammonium persulfate, and the concentration of the main etchant in the etching solution is 10 g/L-100 g/L.
  3. 3. The method for etching a microporous copper foil according to claim 1, wherein the pore structure modifier in the step (2) is a nitrogen-containing heterocyclic compound, an oxyacid salt or a surfactant, and the concentration of the pore structure modifier in the etching solution is 10g/L to 50g/L.
  4. 4. The method for etching the microporous copper foil according to claim 1, wherein the conductive medium in the step (2) is one or more of hydrochloric acid, sulfuric acid, sodium sulfate, ammonium sulfate and potassium nitrate, and the concentration of the conductive medium in the etching solution is 10g/L to 50g/L.
  5. 5. The method for etching a microporous copper foil according to claim 1, wherein the chloride ions in the step (2) are one or more of hydrochloric acid, sodium chloride, ammonium chloride, copper chloride and ferric chloride, and the concentration of the chloride ions in the etching solution is 2g/L to 30g/L.
  6. 6. The method for etching the microporous copper foil according to claim 1, wherein the electrochemical etching process parameters in the step (3) are that the direct current density is 0.1-20A/dm < 2 >, the etching time is 5-180 s, the etching temperature is 20-60 ℃, and the substrate moving speed is 0.1-10 m/min.
  7. 7. The method for etching a micro-porous copper foil according to claim 1, wherein the cathode in the electrochemical etching process in the step (3) is a titanium plate with a platinum, iridium or ruthenium coating on the surface.
  8. 8. The method for etching the microporous copper foil according to claim 1, wherein the etching solution is circularly filtered in the electrochemical etching process in the step (3), and the flow rate is controlled to be 5-30L/min.
  9. 9. A microporous copper foil obtained by the microporous copper foil etching method according to any one of claims 1 to 8.
  10. 10. Use of the microporous copper foil according to claim 9 in the field of secondary batteries.

Description

Micro-pore copper foil etching method Technical Field The invention belongs to the technical field of new energy material manufacturing, and particularly relates to a microporous copper foil etching method. Background With the high-speed development of new energy automobiles and energy storage industry, the demand of lithium ion batteries for high-performance current collectors is increasingly urgent. The copper foil is used as a core material of a lithium ion battery negative electrode current collector, and the microstructure and the surface property of the copper foil directly influence the energy density, the cycle life and the rate capability of the battery. However, the conventional copper foil has limited rate performance and cycle life due to poor adhesion of the active material and poor interfacial stability. The microporous copper foil replaces the traditional copper foil to be used as a key component of a current collector or an electrode material of the secondary battery, so that the microporous copper foil is favorable for loading more active materials, and the capacity of the battery is improved. In addition, the micropores are favorable for the penetration of etching liquid, promote ion transmission and improve the charge and discharge performance, especially the rate performance, of the battery. In addition, the microporous copper foil has lighter weight, so that the whole weight of the battery is reduced, and the energy density of the battery can be effectively improved. At present, the preparation method of the microporous copper foil mainly comprises a laser processing method, a template method, a chemical etching method, an electrochemical etching method and the like, but the method has obvious defects. Although the laser drilling process can realize the positioning of holes, the equipment cost is high, and the heat affected zone generated in the drilling process can cause lattice damage at the edges of the holes, so that the surface performance of the copper foil is deteriorated, and the large-scale application of the copper foil is limited. The template method relies on a cathode roller bump structure, the aperture is more than 60 mu m, the preparation process is complex, the production efficiency is low, and the chemical etching can realize rapid etching, but the surface is easy to excessively corrode, form irregular morphology and influence the mechanical property of the copper foil. Copper is often used as a cathode in the traditional electrochemical etching, the copper cathode is easy to dissolve in the etching process, micropores are blocked after a dissolution product enters etching liquid, the etching liquid is polluted, and the stability of the etching process and the yield of the microporous copper foil are seriously affected. In addition, the prior art has the problems of high control difficulty of micropore morphology, poor repeatability of production process and the like, and is difficult to meet the large-scale production requirement of the battery industry on high-performance and low-cost micropore copper foil. Therefore, development of a microporous copper foil manufacturing method capable of controlling a microporous structure, widening a porosity range, and improving production stability is desired. Disclosure of Invention The technical problem to be solved by the invention is to provide a microporous copper foil etching method, which effectively solves the three technical bottlenecks of difficult control of the microporous morphology, narrow porosity range and poor production stability in the prior art by optimizing the technological parameters and the etching liquid component design. The invention provides a micro-pore copper foil etching method, which comprises the following steps: (1) Using electrolytic copper foil as a base material, and carrying out oil removal and acid washing treatment on the surface of the base material; (2) Preparing an aqueous solution containing a main etchant, a pore structure regulator, a conductive medium and chloride ions as etching liquid; (3) Performing electrochemical etching by using the electrolytic copper foil in the step (1) as an anode by adopting direct current electroplating, and forming uniform micropores on the surface of the electrolytic copper foil; (4) And (5) cleaning, performing anti-oxidation treatment, and drying to obtain the microporous copper foil. Preferably, the main etchant in the step (2) is one or more of sulfuric acid, nitric acid, sodium chlorate, sodium hypochlorite, sodium perchlorate, sodium persulfate and ammonium persulfate, and the concentration of the main etchant in the etching solution is 10 g/L-100 g/L. Preferably, the pore structure regulator in the step (2) is a nitrogen-containing heterocyclic compound, an oxyacid salt or a surfactant, and the concentration of the pore structure regulator in the etching solution is 10 g/L-50 g/L. The pore structure modifier optionally comprises one or more of me