CN217955456U

CN217955456U - Conductive film replacing metal plastic film

Info

Publication number: CN217955456U
Application number: CN202221979881.2U
Authority: CN
Inventors: 刘志康; 严超; 汪茹; 焦鑫鹏
Original assignee: Zhejiang Rouzhen Technology Co ltd
Current assignee: Zhejiang Rouzhen Technology Co ltd
Priority date: 2022-07-29
Filing date: 2022-07-29
Publication date: 2022-12-02
Anticipated expiration: 2032-07-29

Abstract

The utility model provides a replace metal plastic film's conductive film, including metal level and the porous thin layer of polymer, the metal level sets up the both sides of the porous thin layer of polymer, be equipped with on the conductive film and run through the hole of metal level and the porous thin layer of polymer, partial hole packing has metal particle in order to switch on the metal level of the porous thin layer both sides of polymer. The utility model utilizes the metal layer structure filled with partial holes of the polymer film to communicate the metal layers on the two sides of the polymer film layer, thus improving the conductivity of the conductive film, improving the welding effect of the tab and reducing the resistance of the tab; the unfilled holes of the polymer film can be used as ion transmission channels, which is favorable for the uniform distribution of electrolyte. The conductive film can effectively solve the problems that the traditional metal plastic film is single-sided conductive, poor in tab welding effect, incapable of supporting ions to penetrate through and the like.

Description

Conductive film replacing metal plastic film

Technical Field

The utility model belongs to the technical field of the conducting film is relevant, more specifically relates to a replace metal plastic film's conducting film.

Background

Lithium ion batteries have been widely used as energy storage devices in various mobile devices. The market demands for energy density and safety of lithium ion batteries are constantly increasing. The current collectors of the current commercial lithium ion batteries are mainly pure copper foils and pure aluminum foils, but the copper foils and the aluminum foils have very high densities, and the copper foils and the aluminum foils do not contribute to the improvement of the energy density of the lithium ion batteries.

In order to reduce the mass of the current collector, a metal plastic film is adopted to replace a pure metal film as the current collector of the lithium ion battery. Compared with a metal current collector, the metal plastic film composite current collector is lighter in weight, lower in cost and better in safety performance.

Chinese patent CN 110600745A discloses a copper-plated composite current collector prepared based on a polyimide film, and chinese patent CN 106910897A discloses a composite current collector prepared by using a polymeric positive temperature sensitive material (PPTC) as a substrate layer to load metal aluminum or metal copper. However, when such a metal plastic film is used as a current collector, the metal layers on both sides of the polymer film are isolated from each other, which brings about a series of problems: (1) the conductivity is low, and the rate performance of the battery is seriously influenced; (2) in the process of welding with the pole lugs, the welding effect is poor, the required energy is high, and the high internal resistance and even electronic insulation of the welding part are easily caused, so that the multiplying power performance and the energy density of the battery are influenced.

SUMMERY OF THE UTILITY MODEL

To the above defect of prior art or improve the demand, the utility model provides a replace metal plastic film's conductive film, through the metal level of intercommunication conductive film both sides, can obtain showing of conductivity and promote to effectively improve the welding effect of utmost point ear department, reduce the resistance of utmost point ear department. And an ion transmission channel is reserved on the conductive film, so that the electrolyte can be freely diffused in the whole battery, and the function of the conductive film is expanded.

In order to realize the utility model discloses a purpose, the utility model discloses a technical scheme do:

the conductive film for replacing the metal plastic film comprises a metal layer and a high-molecular porous film layer, wherein the metal layer is arranged on two sides of the high-molecular porous film layer, holes penetrating through the metal layer and the high-molecular porous film layer are formed in the conductive film, and metal particles are filled in part of the holes to conduct the metal layer on two sides of the high-molecular porous film layer.

Further, the thickness of the metal layer is 10-10000nm.

Further, the thickness of the polymer porous film layer is 1-40 μm.

Further, the diameter of the holes in the polymer porous film layer is 1-10000nm.

Further, the material of the metal layer includes, but is not limited to, copper (Cu), aluminum (Al), iron (Fe), cobalt (Co), nickel (Ni), titanium (Ti), and the like.

Further, the material of the porous polymer film layer includes, but is not limited to, polymer materials such as polypropylene (PP), polyethylene terephthalate (PET), polyimide (PI), polyethylene (PE), or polyethylene naphthalate (PEN).

Furthermore, the preparation method of the metal layer includes but is not limited to one or a combination of several processes of evaporation coating, magnetron sputtering coating, electroplating and chemical coating.

The utility model has the advantages that:

1. aiming at the problem of insufficient conductivity caused by single-side conduction of a common metal plastic film, the conductivity of the conductive film is obviously enhanced by effectively communicating electron conduction of metal layers on two sides, and the power density of the battery is favorably and fully exerted.

2. The structure that the metal layers on both sides communicate is favorable to improving the welding effect of utmost point ear, reduces the resistance of utmost point ear department, ensures the effective performance of battery multiplying power performance and energy density.

3. The electrolyte can be freely diffused in the whole battery by reserving an ion transmission channel on the metal plastic film. The phenomenon of uneven electrolyte distribution caused by the fact that electrolytes on two sides of a traditional metal plastic film are isolated from each other is avoided.

Drawings

Fig. 1 is a cross-sectional view of the conductive film of the present invention.

Fig. 2 is a plan view of the conductive film of the present invention.

The metal layer, 2, the porous thin film layer of polymer, 3, first hole, 4, second hole wherein.

Detailed Description

In order to more clearly illustrate the present invention, the present invention will be further described in detail with reference to the following embodiments and drawings. It is to be understood by persons skilled in the art that the following detailed description is illustrative and not restrictive, and is not to be taken as limiting the scope of the invention.

As shown in fig. 1 and 2, the present invention provides a conductive film for replacing metal plastic film, which comprises a metal layer 1 and a polymer porous film layer 2, wherein the metal layer 1 is disposed on both sides of the polymer porous film layer 2, the conductive film is provided with holes penetrating through the metal layer 1 and the polymer porous film layer 2, the conductive film comprises a first hole 3 and a second hole 4, the first hole 3 is a hole filled with metal particles, so that electrons can be smoothly conducted between the two metal layers 1; the remaining second holes 4 may serve as a passage for ion migration from one end of the conductive film to the other end of the conductive film through the second holes 4.

Preferably, the thickness of the metal layer is 10-10000nm, the thickness of the polymer porous film layer is 1-40 μm, and the diameter of the holes on the polymer porous film layer is 1-10000nm.

Preferably, the material of the metal layer 1 includes, but is not limited to, copper (Cu), aluminum (Al), iron (Fe), cobalt (Co), nickel (Ni), titanium (Ti), etc.; the material of the porous polymer film layer 2 includes, but is not limited to, polymer materials such as polypropylene (PP), polyethylene terephthalate (PET), polyimide (PI), polyethylene (PE), or polyethylene naphthalate (PEN); the preparation method of the metal layer 1 includes but is not limited to one or a combination of several processes of evaporation coating, magnetron sputtering coating, electroplating and chemical coating. The materials and preparation methods of the metal layer 1 and the polymer porous film layer 2 are not specifically limited in the present application.

Comparative example

The common composite current collector takes a conventional PET film as a high polymer layer, the thickness of the common composite current collector is 6 microns, and aluminum layers with the thickness of 0.75 micron are evaporated on two sides of the PET film.

Example 1

The conductive film takes a porous PET film as a high-molecular porous film layer, the thickness is 6 microns, the aperture is 0.1 micron, and the evaporation process is controlled in two steps. Firstly, evaporating a layer of aluminum layer with the thickness about 100nm on two sides of a porous PET film, controlling the evaporation speed of an evaporation boat to change intermittently in the evaporation process, filling up the empty holes by larger aluminum particles (dozens to hundreds of nanometers) in a high-speed evaporation area (the speed of an aluminum wire is 1000 m/min), and filling up the size of the aluminum particles to dozens of nanometers in a low-speed area (the speed of the aluminum wire is 400 m/min) so as to obtain the empty hole area. And secondly, carrying out uniform aluminum layer evaporation, wherein the diameter of aluminum particles obtained by evaporation is from several nanometers to dozens of nanometers, the holes are reserved, and aluminum layers with the thickness of 0.75 micrometer are obtained except hole areas.

Example 2

The conductive film uses a porous PET film as a polymer porous film layer, the thickness of the porous PET film is 6 micrometers, the pore diameter of the porous PET film is 0.2 micrometer, aluminum layers with the thickness of 0.75 micrometer are evaporated on two sides of the porous PET film, and the processing method of a hole area is as shown in example 1.

The conductive films in comparative example and examples 1-2 were compared for sheet resistance, conductivity, and electrolyte contact angle:

the conductive film constructed by the polymer porous film layer and the metal layers can effectively communicate the electronic conduction of the metal layers on two sides, and compared with a common metal plastic film, the sheet resistance of the conductive film is obviously reduced, and the conductivity is obviously enhanced; after the welding of the electrode lug, the resistance of the electrode lug is obviously reduced; in addition, the holes of the partially unfilled porous polymer film layer can be infiltrated by the electrolyte, so that an ion transmission channel is provided, and the infiltration of the electrolyte is obviously enhanced.

It will be understood by those skilled in the art that the foregoing is merely a preferred embodiment of the present invention, and is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

Claims

1. The conductive film is characterized by comprising a metal layer and a high-molecular porous film layer, wherein the metal layer is arranged on two sides of the high-molecular porous film layer, holes penetrating through the metal layer and the high-molecular porous film layer are formed in the conductive film, and metal particles are filled in part of the holes to conduct the metal layer on two sides of the high-molecular porous film layer.

2. The conductive film as claimed in claim 1, wherein the metal layer has a thickness of 10 to 10000nm.

3. The conductive film as claimed in claim 1 or 2, wherein the thickness of the polymer porous film layer is 1 to 40 μm.

4. The conductive film as claimed in claim 1, wherein the diameter of the pores in the porous polymer film layer is 1-10000nm.