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CN-122000363-A - Double-sided communicated functional current collector and preparation method and application thereof

CN122000363ACN 122000363 ACN122000363 ACN 122000363ACN-122000363-A

Abstract

The invention provides a double-sided communication type functional current collector, a preparation method and application thereof, wherein the double-sided communication type functional current collector comprises a macromolecule-based film layer and metal layers arranged on the surfaces of two sides of the macromolecule-based film layer, through holes are distributed on the surfaces of the double-sided communication type functional current collector, and the metal layers cover the inner walls of the through holes, so that the metal layers on the surfaces of the two sides of the macromolecule based film layer are directly conducted. The preparation method comprises the steps of (1) punching a polymer base film to obtain a polymer base film layer with through holes distributed on the surface, (2) depositing metal layers on the two side surfaces of the polymer base film layer and the inner walls of the through holes in a chemical plating mode, and (3) thickening the metal layers to a target thickness in a water electroplating mode to obtain the double-sided communication type functional current collector. The functional current collector provided by the invention effectively solves the problems of difficult conduction, limited flow conductivity and low electrolyte infiltration efficiency of the conventional composite copper foil double-sided metal layer, and remarkably improves the battery performance.

Inventors

  • LIU KE
  • ZHU ZHONGYA
  • HAN MENGJIE
  • XIA JIANZHONG
  • LI XUEFA

Assignees

  • 扬州纳力新材料科技股份有限公司

Dates

Publication Date
20260508
Application Date
20260202

Claims (10)

  1. 1. The double-sided communication type functional current collector comprises a macromolecule-based film layer and metal layers arranged on the surfaces of two sides of the macromolecule-based film layer, and is characterized in that through holes are distributed on the surfaces of the double-sided communication type functional current collector, and the metal layers cover the inner walls of the through holes, so that the metal layers on the surfaces of two sides of the macromolecule-based film layer are directly conducted.
  2. 2. The double-sided communication functional current collector of claim 1, wherein the through-hole satisfies at least one of the following conditions: the average pore diameter of the through holes is 5-500 mu m; The hole spacing between adjacent through holes is 0.1-10mm; at least one side of the through hole is in an annular bulge structure; the coverage rate of the metal layer on the inner wall of the through hole is 100%; the strength ratio of (111)/(200) of the metal layer on the inner wall of the through hole is (1-5): 1; the carbon-containing mass ratio of the inner wall of the through hole is 0.1-20%, and more preferably 0.1-5%; The thickness of the metal layer on the inner wall of the through hole is thinner than that of the metal layers on the surfaces on two sides of the high polymer base film layer.
  3. 3. The double-sided communication functional current collector of claim 2, wherein the thickness of the metal layer on the inner wall of the through hole is 1/5 to 4/5 of the thickness of the metal layer on the two side surfaces of the polymer-based film layer.
  4. 4. The double-sided communication type functional current collector according to claim 2 or 3, wherein the through holes are in non-uniform pore size distribution along the length direction of the functional current collector, and the pore size of the through holes of the tab welding region is larger than that of the non-tab welding region; Wherein the aperture of the through hole of the tab welding area is 50-100 mu m; and/or the aperture of the through hole of the non-tab welding area is 5-50 μm.
  5. 5. The double-sided communication type functional current collector according to claim 2 or 3, wherein the through holes are distributed with non-uniform hole pitch along the length direction of the functional current collector, and the hole pitch of the tab welding area is smaller than that of the non-tab welding area; The hole spacing of the tab welding area is 0.1-5mm; And/or the hole spacing of the non-tab welding area is 5-10mm.
  6. 6. The double-sided communication functional current collector according to claim 2 or 3, wherein a primer layer is further provided between the polymer-based film layer and the metal layer; wherein, the material of the priming layer comprises metal palladium; And/or the thickness of the bottom layer is 20-100nm.
  7. 7. The double-sided communication functional current collector of claim 2 or 3, wherein the polymer-based film layer comprises at least one of polyethylene terephthalate, polypropylene, or polyimide; And/or the thickness of the macromolecule-based film layer is 2-8 μm; And/or the material of the metal layer comprises at least one of copper, aluminum, zinc, iron, nickel, titanium, gold, silver or chromium; and/or the thickness of the metal layer is 0.8-1.2 μm; and/or the metal layers on the two side surfaces of the polymer base film layer are the same or different in material.
  8. 8. A method for preparing the double-sided communication type functional current collector as claimed in any one of claims 1 to 7, wherein the preparation method comprises the following steps: (1) Punching the polymer-based film to obtain a polymer-based film layer with through holes distributed on the surface; (2) Depositing metal layers on the surfaces of the two sides of the polymer base film layer and the inner wall of the through hole in a chemical plating mode; (3) And thickening the metal layer to a target thickness by adopting a water electroplating mode to obtain the double-sided communicated functional current collector.
  9. 9. The method for preparing a double-sided communication functional current collector according to claim 8, wherein the punching treatment in the step (1) comprises laser punching; Wherein the laser type adopted by the laser drilling comprises nanosecond laser; And/or, cleaning and ion beam treatment are sequentially carried out on the macromolecule-based film layer before the electroless plating in the step (2); And/or, the activating solution used in the electroless plating in the step (2) contains palladium salt and a reducing agent; and/or, the current intensity adopted by the hydropower plating in the step (3) is 4-25A; And/or, after the step (3) of water electroplating, washing, antioxidation, drying and rolling the functional current collector in sequence.
  10. 10. A bipolar battery comprising the double-sided communication type functional current collector as claimed in any one of claims 1 to 7, wherein the materials of the metal layers on both side surfaces of the polymer sub-film layer of the double-sided communication type functional current collector are different, one side is used for leading out positive current, the other side is used for leading out negative current, the surface of the current collector for leading out positive current is provided with a positive active material layer, and the surface of the current collector for leading out negative current is provided with a negative active material layer.

Description

Double-sided communicated functional current collector and preparation method and application thereof Technical Field The invention belongs to the technical field of battery manufacturing, and relates to a functional current collector, in particular to a double-sided communication functional current collector, and a preparation method and application thereof. Background Under the background of rapid development of new energy industry, the lithium battery is used as a core energy storage device, the energy density, the safety, the light weight and the production efficiency of the lithium battery become the core direction of technological breakthrough, and the current collector is used as a key component for bearing active materials and conducting current in the lithium battery, so that the comprehensive performance of the battery is directly affected. At present, a current collector adopted by the lithium battery is mainly made of traditional aluminum foil and copper foil, but the problems of high density and heavy weight exist, and the further improvement of the light weight and the energy density of the battery is restricted. Aiming at the problems, the composite copper foil realizes the advantages of weight reduction and thinning through the sandwich structure of the middle polymer base film and the double-sided metal layer, and the insulation characteristic of the polymer base film obviously improves the puncture safety of the battery, so the composite copper foil becomes an important development direction of the current collector technology. However, the structural characteristics of the composite copper foil also bring about a new technical problem that the middle polymer base film is in an insulating state and cannot realize direct conduction of the upper and lower double-sided metal layers, and the current conduction is the premise that the current collector plays a conductive function, so that the problem directly limits the industrialized application of the composite copper foil. In order to solve the problem of conduction of the AB surface metal layer, a transfer welding process is mainly adopted in the industry, namely two independent copper foils are respectively welded on the AB sides of the composite current collector to lead out current. However, the scheme needs to additionally increase a transfer welding process, so that the production flow of the battery cell is prolonged, the processing cost is increased, the welding width occupies the effective space of the tab position, more importantly, the current can be conducted only through the width of the welding wire, the flow guiding area is limited to the size of the welding wire, the flow guiding capacity is insufficient, and the internal resistance of the battery cell is further increased. In addition, the existing composite copper foil has the problem of low electrolyte infiltration efficiency. Due to the compact structure of the polymer base film and the metal layer, electrolyte is difficult to permeate into the pole piece rapidly, so that the injection time is prolonged, the production efficiency of the battery core is affected, meanwhile, the electrolyte is unevenly distributed, the concentration of local lithium ions is too low, so that the lithium precipitation phenomenon is caused, and the cycle life and the safety of the battery are reduced. Therefore, how to provide a current collector overcomes the defects of difficult conduction, limited flow conductivity and low electrolyte infiltration efficiency of the conventional composite copper foil double-sided metal layer, improves the battery performance, and becomes a problem to be solved by the current technicians in the field. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide a double-sided communication type functional current collector, a preparation method and application thereof, overcome the defects of difficult conduction, limited flow conductivity and low electrolyte infiltration efficiency of the conventional composite copper foil double-sided metal layer, and improve the performance of a battery. In order to achieve the aim of the invention, the invention adopts the following technical scheme: in a first aspect, the invention provides a double-sided communication type functional current collector, which comprises a macromolecule-based film layer and metal layers arranged on two side surfaces of the macromolecule-based film layer, wherein through holes are distributed on the surfaces of the double-sided communication type functional current collector, and the metal layers cover the inner walls of the through holes, so that the metal layers on the two side surfaces of the macromolecule-based film layer are directly conducted. According to the invention, the through holes are formed in the surface of the functional current collector, and the metal layers are covered on the inner walls of the through holes, so that the metal layers on t