A lithium battery composite current collector and a manufacturing method thereof

Abstract

The application discloses a lithium battery composite current collector and a manufacturing method thereof. The current collector comprises a plastic film, a first prefabricated adhesive layer, a first copper metal layer and a second copper metal layer arranged on one side of the plastic film, and a second prefabricated adhesive layer, a first aluminum metal layer and a second aluminum metal layer arranged on the other side of the plastic film. The first copper metal layer and the first aluminum metal layer are formed by magnetron sputtering coating, and the second copper metal layer and the second aluminum metal layer are formed by vacuum evaporation coating. The lithium battery composite current collector can realize the manufacturing of a bipolar ultrathin current collector by continuous coating on a single device, and the density of the film is high. The manufacturing process can effectively avoid the problems of corrosion and peeling of the film layer.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of lithium ion batteries, in particular to a lithium battery composite current collector and a manufacturing method thereof. BACKGROUND

[0002] High conductivity, high strength, high flexibility and ultra-thin current collector are the development trend of future lithium battery current collector. The commonly used positive and negative current collectors of lithium battery mainly include ductile copper foil, electrolytic copper foil and ductile aluminum foil. Among them, the ductile copper foil and aluminum foil can be usually made to 10-16 um by rolling, but it is difficult to continue to be thin, and the finished product quality cannot be further improved. The electrolytic copper solution can produce 6-8 um copper foil, but the characteristics of electrolysis will cause the roughness of the two sides of the copper foil to be too large, and additional surface treatment process is needed. The processing technology of electrolyte is easy to cause additional pollution, resulting in a too complex overall process. Especially for the process of combining the positive current collector and the negative current collector into one, it is more difficult to realize due to the incomplete compatibility of the electrolyte to the metal of opposite polarity. SUMMARY

[0003] In view of the above problems, the present application provides a lithium battery composite current collector and a manufacturing method thereof, which realizes high density and anti-peeling ability of the bipolar current collector by combining magnetron sputtering and vacuum evaporation film plating, and avoids the corrosion of electrolyte to the metal layer.

[0004] To solve the above technical problems, the present application provides a lithium battery composite current collector, characterized in that the lithium battery composite current collector comprises: a plastic film, a first pre-prepared adhesive layer, a first copper metal layer and a second copper metal layer arranged on one side of the plastic film; a second pre-prepared adhesive layer, a first aluminum metal layer and a second aluminum metal layer arranged on the other side of the plastic film. The first copper metal layer and the first aluminum metal layer are formed by magnetron sputtering film plating; the second copper metal layer and the second aluminum metal layer are formed by vacuum evaporation film plating.

[0005] Further, the thickness of the first copper metal layer is 30-150 nm; the thickness of the second copper metal layer is 300-1500 nm.

[0006] Further, the thickness of the first aluminum metal layer is 30-150 nm; the thickness of the second aluminum metal layer is 300-1500 nm.

[0007] Further, the material of the plastic film is any one of PP, PET and PI.

[0008] Further, the thickness of the plastic film is 2-20 um.

[0009] Further, the material of the first pre-prepared adhesive layer is any one of nickel, nickel copper, titanium and silicon, and the thickness is 2-10 nm.

[0010] Further, the material of the second pre-preparation adhesive layer is any one of nickel, titanium and silicon, and the thickness is 2-10 nm;

[0011] Further, an ITO protective layer is further arranged on the second copper metal layer, and the thickness of the ITO protective layer is 5-20 nm;

[0012] The application further provides a manufacturing method of the lithium battery composite current collector.

[0013] A plastic film is provided.

[0014] A first pre-preparation adhesive layer and a first copper metal layer are sequentially plated on one side of the plastic film by a magnetron sputtering plating technology, and a second copper metal layer is plated by a vacuum evaporation plating technology.

[0015] A second pre-preparation adhesive layer and a first aluminum metal layer are sequentially plated on the other side of the plastic film by the magnetron sputtering plating technology, and a second aluminum metal layer is plated by the vacuum evaporation plating technology.

[0016] Further, the manufacturing method of the lithium battery composite current collector further comprises the step that an ITO protective layer is plated on the second copper metal layer by the magnetron sputtering plating technology.

[0017] The application has the following advantages:

[0018] (1) The first copper metal layer and the first aluminum metal layer are formed by the vacuum magnetron sputtering plating method, the film layer structure is dense, the adhesion is good, and the plastic film substrate has better bonding force; since the formed film layer is thin, the problem of slow deposition rate also avoids affecting the production efficiency;

[0019] (2) The second copper metal layer or the second aluminum metal layer is formed on the first copper metal layer or the first aluminum metal layer by the vacuum evaporation plating to achieve the required metal film thickness, and the production efficiency is improved;

[0020] (3) The positive electrode current collector and the negative electrode current collector can be continuously plated on a single device to realize the manufacturing of the bipolar ultrathin current collector, and the problem of film layer corrosion and peeling is also avoided;

[0021] In summary, the lithium battery composite current collector of the application, the positive electrode current collector and the negative electrode current collector can be continuously plated on a single device to realize the manufacturing of the bipolar ultrathin current collector, and the film is dense, and the manufacturing process can effectively avoid the problem of film layer corrosion and peeling. BRIEF DESCRIPTION OF DRAWINGS

[0022] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0023] Figure 1 This is a schematic diagram of a lithium battery composite current collector structure provided by the present invention;

[0024] Figure 2 The present invention provides a manufacturing process for a lithium battery composite current collector;

[0025] Figure 3 This is a schematic diagram of another lithium battery composite current collector structure provided by the present invention;

[0026] Figure 4 Another process for manufacturing a lithium battery composite current collector provided by the present invention;

[0027] Explanation of reference numerals in the attached drawings: plastic film 10, first pre-adhesive layer 20, first copper metal layer 30, second copper metal layer 31, second pre-adhesive layer 21, first aluminum metal layer 40, second aluminum metal layer 41, ITO protective layer 50. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0029] Example 1

[0030] like Figure 1 As shown, the present invention provides a lithium battery composite current collector, comprising: a plastic film 10 and a first pre-adhesive layer 20, a first copper metal layer 30, and a second copper metal layer 31 disposed on one side of the plastic film; and a second pre-adhesive layer 21, a first aluminum metal layer 40, and a second aluminum metal layer 41 disposed on the other side of the plastic film. The first copper metal layer 30 and the first aluminum metal layer 40 are formed by magnetron sputtering; the second copper metal layer 31 and the second aluminum metal layer 41 are formed by vacuum evaporation; the thickness of the first copper metal layer is 30-150 nm; the thickness of the second copper metal layer is 300-1500 nm; the thickness of the first aluminum metal layer is 30-150 nm; the thickness of the second aluminum metal layer is 300-1500 nm; the plastic film material is any one of PP, PET, and PI; the thickness of the plastic film is 2-20 μm; the material of the first pre-adhesive layer is any one of nickel, nickel-copper, titanium, and silicon; the material of the second pre-adhesive layer is any one of nickel, titanium, and silicon; the thickness of the first and second pre-adhesive layers is 2-10 nm.

[0031] As Figure 2 shown, the application also provides a method for manufacturing the lithium battery composite current collector, comprising the steps of:

[0032] A plastic film is provided, which can be made of any one of PP, PET and PI, and can be smooth or roughened by existing technology, and has a thickness of 2-20 um;

[0033] A first pre-prepared adhesive layer 2-10 nm and a first copper metal layer 30-150 nm are sequentially plated on one side of the plastic film by magnetron sputtering plating technology, and a second copper metal layer 300-1500 nm is plated by vacuum evaporation plating technology;

[0034] A second pre-prepared adhesive layer 2-10 nm and a first aluminum metal layer 30-150 nm are sequentially plated on the other side of the plastic film by magnetron sputtering plating technology, and a second aluminum metal layer 300-1500 nm is plated by vacuum evaporation plating technology;

[0035] Example 2

[0036] The application also provides another lithium battery composite current collector, which is different from example 1 in that an ITO protective layer 50 is further provided on the surface of the second copper metal layer 31, and the ITO protective layer has a thickness of 5-20 nm. The structure of the lithium battery composite current collector is shown in Figure 3 .

[0037] As Figure 4 shown, the method for manufacturing the lithium battery composite current collector is different from example 1 in that the method further comprises the step of plating an ITO protective layer 5-20 nm on the surface of the second copper metal layer after the completion of the second copper metal layer by magnetron sputtering plating technology. The specific process comprises:

[0038] A plastic film is provided, which can be made of any one of PP, PET and PI, and can be smooth or roughened by existing technology, and has a thickness of 2-20 um;

[0039] A first pre-prepared adhesive layer 2-10 nm and a first copper metal layer 30-150 nm are sequentially plated on one side of the plastic film by magnetron sputtering plating technology, and a second copper metal layer 300-1500 nm is plated by vacuum evaporation plating technology; an ITO protective layer 5-20 nm is plated by magnetron sputtering plating technology; the ITO protective layer plays a role in preventing oxidation of the copper metal layer and reducing the impact on the conductivity;

[0040] A second pre-preparation bonding layer 2-10nm and a first aluminum metal layer 30-150nm are coated on the other side of the plastic film by magnetron sputtering coating technology, and a second aluminum metal layer 300-1500nm is coated by vacuum evaporation coating technology.

[0041] The lithium battery composite current collector, the positive electrode current collector and the negative electrode current collector of the application can be continuously coated on a single device, the production of bipolar ultra-thin current collectors is realized, the density of the film is high, and the production process can effectively avoid the problems of corrosion and peeling of the film layer.

[0042] The above merely describes the preferred embodiments of the present application, and is not intended to limit the present application. Any modification, equivalent replacement and improvement within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A lithium battery composite current collector, characterized by: The current collector comprises a plastic film, a first pre-prepared adhesive layer, a first copper metal layer and a second copper metal layer arranged on one side of the plastic film, a second pre-prepared adhesive layer, a first aluminum metal layer and a second aluminum metal layer arranged on the other side of the plastic film; the first copper metal layer and the first aluminum metal layer are formed by magnetron sputtering film plating; the second copper metal layer and the second aluminum metal layer are formed by vacuum evaporation film plating; the thickness of the first copper metal layer is 30-150 nm; the thickness of the second copper metal layer is 300-1500 nm; the thickness of the first aluminum metal layer is 30-150 nm; the thickness of the second aluminum metal layer is 300-1500 nm; the thickness of the first pre-prepared adhesive layer is 2-10 nm; the thickness of the second pre-prepared adhesive layer is 2-10 nm; an ITO protective layer is further arranged on the second copper metal layer; the thickness of the ITO protective layer is 5-20 nm.

2. The lithium battery composite current collector of claim 1, further characterized by: The plastic film is made of one of PP, PET and PI, and has a thickness of 2-20 um.

3. The lithium battery composite current collector of claim 1, further comprising: The first pre-prepared adhesive layer is made of any one of nickel, nickel-copper, titanium and silicon.

4. The lithium battery composite current collector of claim 1, further comprising: The second pre-prepared adhesive layer is made of any one of nickel, titanium and silicon.

5. The method of claim 1-4, wherein: The method for manufacturing the lithium battery composite current collector comprises the following steps: providing a plastic film; arranging a first pre-prepared adhesive layer and a first copper metal layer on one side of the plastic film by magnetron sputtering film plating, and arranging a second copper metal layer by vacuum evaporation film plating; arranging a second pre-prepared adhesive layer and a first aluminum metal layer on the other side of the plastic film by magnetron sputtering film plating, and arranging a second aluminum metal layer by vacuum evaporation film plating.

6. The method of claim 5, further comprising: The method for manufacturing the lithium battery composite current collector comprises the following steps: providing a plastic film; arranging a first pre-prepared adhesive layer and a first copper metal layer on one side of the plastic film by magnetron sputtering film plating, arranging a second copper metal layer by vacuum evaporation film plating, and arranging an ITO protective layer on the second copper metal layer by magnetron sputtering film plating; arranging a second pre-prepared adhesive layer and a first aluminum metal layer on the other side of the plastic film by magnetron sputtering film plating, and arranging a second aluminum metal layer by vacuum evaporation film plating.

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