CN-115440985-B - Preparation method and preparation device of composite current collector

CN115440985BCN 115440985 BCN115440985 BCN 115440985BCN-115440985-B

Abstract

The invention relates to a preparation method and a preparation device of a composite current collector, which are characterized in that an active area is formed in the middle of the surface of a base material belt through selective pretreatment, and a blank area is not treated in the pretreatment process, so that the edges of the two sides of the base material belt are not damaged. In addition, in the process of forming the metal layer, the operation is performed only on the active region, and the metal layer is not formed in the blank region. In addition, damage such as perforation to the base material tape during formation of the metal layer often occurs at the edge of the metal layer. Therefore, damage to the edge of the base material belt can be reduced as much as possible in the preparation process, so that the high mechanical strength of the base material belt is maintained. Moreover, damage at the edge of the metal layer can be subsequently removed. Therefore, the preparation method of the composite current collector can remarkably improve the yield.

Inventors

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Assignees

上海先导慧能技术有限公司

Dates

Publication Date: 20260508
Application Date: 20220906

Claims (8)

1. A method of preparing a composite current collector, comprising the steps of: Providing a base material strip; Forming an active area in the middle of the surface of the base material belt, and forming a blank area at two side edges of the base material belt along the width direction, wherein the active area and the blank area are both strip-shaped and extend along the length direction of the base material belt; the step of forming a metal layer in the active region when the composite current collector is a negative composite current collector includes electroless plating the base material tape to form a metal film attached to the active region, electroplating the base material tape subjected to electroless plating to form the metal layer of a preset thickness on the surface of the metal film, and when the composite current collector is a positive composite current collector, forming a metal layer in the active region includes electroless plating the base material tape to form the metal layer of a preset thickness in the active region; And cutting off edge parts of the two sides of the metal layer along the width direction or the blank area to prepare the composite current collector.
2. The method of preparing a composite current collector according to claim 1, wherein the step of forming an active region in a middle portion of the surface of the base material tape and forming a blank region at both side edges of the base material tape in the width direction comprises: Coarsening the middle part of the surface of the base material belt; Coating a sensitization activating solution on the coarsened area to form the active area; wherein the blank-retaining region is formed in a region where both side edges of the base material belt in the width direction are not roughened and are not coated with the sensitization-activation liquid.
3. The method for preparing a composite current collector according to claim 2, wherein the roughening the middle of the surface of the base material tape comprises roughening a plurality of stripe-shaped regions of the surface of the base material tape, the stripe-shaped regions being located at the middle of the surface of the base material tape and being disposed at intervals in a width direction of the base material tape; And coating sensitization activating solution on the strip-shaped areas after roughening treatment to form the active areas, wherein the blank area is formed in the areas which are not roughened and are not coated with sensitization activating solution between adjacent strip-shaped areas.
4. The method of preparing a composite current collector according to claim 1, wherein said base material strip is electroplated by means of brush plating.
5. The method of preparing a composite current collector according to claim 1, further comprising the step of forming an oxidation resistant layer on a surface of said metal layer facing away from said base material strip after said step of forming a metal layer in said active region.
6. The method for preparing a composite current collector according to claim 1, wherein the base material tape is unwound in a continuous tape-feeding manner, and the prepared composite current collector is wound in a continuous tape-feeding manner.
7. A composite current collector preparation apparatus, comprising: The unreeling mechanism is used for providing a base material belt; The pretreatment mechanism is used for forming an active area in the middle of the surface of the base material belt, and forming a blank area at two side edges of the base material belt along the width direction, wherein the active area and the blank area are both strip-shaped and extend along the length direction of the base material belt; the coating mechanism is used for forming a metal layer in the active area; when the composite current collector is a cathode composite current collector, the coating mechanism can carry out chemical plating on the base material belt to form a metal film attached to the active area, and electroplate the base material belt subjected to chemical plating to form the metal layer with preset thickness on the surface of the metal film; And the trimming mechanism is used for cutting off edge parts of the two sides of the metal layer along the width direction or the blank area so as to prepare the composite current collector.
8. The composite current collector manufacturing apparatus of claim 7, wherein the unwind mechanism is capable of continuously unwinding the base material strip, the composite current collector manufacturing apparatus further comprising a wind-up mechanism capable of continuously winding the composite current collector.

Description

Preparation method and preparation device of composite current collector Technical Field The invention relates to the technical field of lithium battery equipment, in particular to a preparation method and a preparation device of a composite current collector. Background Composite current collectors employing polymeric materials as the substrate are receiving increasing attention from the standpoint of reducing the weight of lithium batteries, increasing the energy density of the batteries, and the like. The composite current collector comprises a substrate and metal layers formed on the upper surface and the lower surface of the substrate, wherein the substrate has a supporting function, and the metal layers on the two sides have a conducting function. At present, a common preparation method is to deposit metal films with certain thickness on two sides of a substrate through a physical vapor deposition method, and then electroplate or chemically plate the substrate with the metal films formed on the two sides, so that the metal films on the two sides are thickened until the conductivity and physical characteristics of the composite current collector meet the requirements of a lithium battery. The vacuum physical vapor deposition is accompanied with high temperature, and the substrate is easy to deform, wrinkle, blow-by, perforation, embrittlement and the like under the high temperature environment. Moreover, the substrate is very thin and light, and the impact of high-energy particles during vacuum sputtering, corrosion during electroless plating and edge current effect during electroplating are all easy to cause perforation and breakage of the substrate. Particularly, in the process of roll-to-roll preparation, the substrate is required to bear the tension of a travelling belt, so that the damage of the edge of the substrate is extremely easy to cause the breakage of the belt. Therefore, the existing method results in lower yield when preparing the composite current collector. Disclosure of Invention In view of the above, it is desirable to provide a method and an apparatus for manufacturing a composite current collector, which can improve yield. A method of preparing a composite current collector comprising the steps of: Providing a base material strip; Forming an active area in the middle of the surface of the base material belt, and forming a blank area at two side edges of the base material belt along the width direction, wherein the active area and the blank area are both strip-shaped and extend along the length direction of the base material belt; forming a metal layer in the active region; And cutting off edge parts of the two sides of the metal layer along the width direction or the blank area to prepare the composite current collector. In one embodiment, the step of forming an active region in the middle of the surface of the base material belt and forming a blank region at both side edges of the base material belt in the width direction includes: Coarsening the middle part of the surface of the base material belt; Coating a sensitization activating solution on the coarsened area to form the active area; wherein the blank-retaining region is formed in a region where both side edges of the base material belt in the width direction are not roughened and are not coated with the sensitization-activation liquid. In one embodiment, the roughening treatment of the middle part of the surface of the base material belt comprises roughening treatment of a plurality of strip-shaped areas of the surface of the base material belt, wherein the strip-shaped areas are positioned at the middle part of the surface of the base material belt and are arranged at intervals along the width direction of the base material belt; And coating sensitization activating solution on the strip-shaped areas after roughening treatment to form the active areas, wherein the blank area is formed in the areas which are not roughened and are not coated with sensitization activating solution between adjacent strip-shaped areas. In one embodiment, the composite current collector comprises a negative composite current collector, and the step of forming a metal layer in the active region comprises: Electroless plating the base material strip to form a metal film attached to the active region; Electroplating the base material strip subjected to electroless plating to form the metal layer with a preset thickness on the surface of the metal film. In one embodiment, the base material strip is electroplated by means of brush plating. In one embodiment, the composite current collector comprises a positive composite current collector, and the step of forming a metal layer in the active region comprises electroless plating the base material strip to form the metal layer of a predetermined thickness in the active region. In one embodiment, after the step of forming a metal layer in the active region, the method further comprises the step of forming