WO2024011536A1 - Copper composite current collector, preparation method therefor and application thereof - Google Patents

Abstract

The present invention relates to the field of lithium ion batteries, and specifically to a copper composite current collector, a preparation method therefor and an application thereof. The preparation method for a copper composite current collector comprises the following steps: providing a polymer film; by using vacuum evaporation technology, making the polymer film pass through a copper-plated roller, and dividing the temperature of the copper-plated roller into a first temperature area and a second temperature area in the axial direction of the copper-plated roller, wherein the temperature in the first temperature area is 40-50℃, and the temperature in the second temperature area is 10-20℃; and evaporating metal copper under a vacuum condition, so as to plate copper metal layers on two surfaces of the polymer film. The copper composite current collector prepared by means of the preparation method for a copper composite current collector has a high specific surface area, and can reduce the interface resistance of a battery.

Description

Copper composite current collector and its preparation method and application Technical field

The present invention relates to the field of lithium-ion batteries, and specifically to a copper composite current collector and its preparation method and application.

Background technique

At present, the surface of the copper metal layer on the surface of conventional copper composite current collectors is flat and very smooth. The surface roughness is low, the surface energy is low, and the specific surface area is also low. This causes the copper composite current collector to have difficulty in coating electrode slurry. The following problems will occur: 1) The electrode slurry is prone to leakage, which reduces the product quality and limits the coating speed; 2) Due to the low specific surface area of the copper metal layer, the active material layer in the battery and the copper metal layer The bonding area is small, resulting in a low bonding force between the active material layer and the composite current collector in the battery, which is prone to powder falling off; at the same time, the small bonding area also leads to a conductive channel between the active material and the composite current collector. Small, increasing the interface resistance between the active material and the composite current collector copper metal layer interface.

Contents of the invention

Based on this, it is necessary to provide a copper composite current collector that can increase the specific surface area while reducing the interface resistance and its preparation method and application.

On the one hand, the present invention provides a preparation method of copper composite current collector, which includes the following steps:

Provide polymer films;

Using vacuum evaporation technology, the polymer film is passed through a copper plating roller along the axial direction of the copper plating roller. The copper plating roller has a first temperature zone and a second temperature zone. The first temperature zone The temperature of the second temperature zone is 40°C to 50°C, and the temperature of the second temperature zone is 10°C to 20°C; and

Metal copper is evaporated under vacuum conditions to plate copper metal layers on both sides of the polymer film.

In one embodiment, the lengths of the first temperature zone and the second temperature zone of the copper plating roller are independently 5 mm to 10 mm.

In one embodiment, the vacuum degree for evaporating the metallic copper is 10-4Pa to 10-5Pa, the temperature is 1600°C to 1800°C, and the concentration of copper vapor is maintained at 60mol/L to 80mol/L.

In one embodiment, during the process of plating the copper metal layer, the movement speed of the polymer film is 10 m/min to 100 m/min.

In one embodiment, the material of the polymer film is selected from the group consisting of a composite of an insulating polymer material and an inorganic non-conductive filler, a composite of an insulating polymer material and a conductive filler, an insulating polymer material or a conductive polymer. Material, wherein the mass percentage of the insulating polymer material in the composite formed by the insulating polymer material and the inorganic non-conductive filler is ≥90%, and the insulation in the composite formed by the insulating polymer material and the conductive filler The mass percentage of polymer material is ≥90%.

In one embodiment, the insulating polymer material is selected from the group consisting of cellulose and its derivatives, starch and its derivatives, protein and its derivatives, polyvinyl alcohol and its cross-linked polymers, polyethylene glycol and its Cross-linked polymer, polyamide, polyterephthalate, polyimide, polyethylene, polypropylene, polystyrene, polyvinyl chloride, aramid, polyphenylenediamide, acrylonitrile-butan Diene-styrene copolymer, polyethylene terephthalate, polybutylene terephthalate, poly(p-phenylene terephthalamide), polypropylene, polyformaldehyde, epoxy resin, phenolic resin One or more of resin, polytetrafluoroethylene, polyvinylidene fluoride, silicone rubber and polycarbonate.

In one embodiment, the conductive polymer material is selected from doped polysulfide nitride and/or doped polyacetylene.

In one embodiment, the inorganic non-conductive filler is selected from one or more of ceramic materials, glass materials and ceramic composite materials.

In one embodiment, the conductive filler is selected from the group consisting of carbon black, carbon nanotubes, graphite, acetylene black, graphene, nickel, iron, copper, aluminum, alloys, nickel-coated graphite powder, and nickel-coated carbon fiber. one or more of them.

In one aspect, the present invention also provides a copper composite current collector, which is prepared by the above-mentioned preparation method of a copper composite current collector.

In one embodiment, the copper composite current collector has at least one of the following properties:

(1) Surface roughness＞0.2μm;

(2) Specific surface area >20m ² /g;

(3) The number of surface pores is >10/m ² and the pore diameter is ≥10nm;

(4) Puncture strength ≥200gf;

(5) Longitudinal tensile strength ≥ 150MPa, longitudinal elongation ≥ 10%, transverse tensile strength ≥ 150Mpa, transverse elongation ≥ 10%.

In another aspect, the present invention further provides a negative electrode, which includes the above-mentioned copper composite current collector and a negative electrode active material layer located on one or both sides of the copper composite current collector.

In yet another aspect, the present invention provides a lithium ion battery, which includes the above-mentioned negative electrode.

In another aspect, the present invention provides an electrical device that uses the above-mentioned lithium-ion battery as a power source.

The preparation method of the above-mentioned copper composite current collector regulates the temperature of the copper plating roller so that it has different temperature zones, so that the copper metal layer can be plated on the surface of the polymer film at different speeds, thereby increasing the growth of copper crystals in the copper metal layer. The speed is different to form a hole structure on the surface of the copper metal layer. The formation of the pore structure increases the roughness and specific surface area of the copper composite current collector, thereby increasing the contact area between the active material and the copper composite current collector in the battery, increasing the coating amount of the active material, and reducing the internal temperature of the battery. resistance, improve battery capacity and energy density, and extend battery cycle life.

Description of drawings

In order to more clearly explain the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings that need to be used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description The drawings illustrate some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without exerting any creative effort.

Figure 1 is an SEM image of the copper composite current collector prepared in Example 1.

Detailed ways

Reference will now be made in detail to embodiments of the invention, one or more examples of which are described below. Each example is provided by way of explanation, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For example, features illustrated or described as part of one embodiment can be used in another embodiment, to yield still further embodiments.

Thus, it is intended that the present invention cover such modifications and variations as come within the scope of the appended claims and their equivalents. Other objects, features, and aspects of the invention are disclosed in, or are apparent from, the following detailed description. Those of ordinary skill in the art will appreciate that this discussion is merely a description of exemplary embodiments and is not intended to limit the broader aspects of the invention.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which the invention belongs. The terminology used herein in the description of the invention is for the purpose of describing specific embodiments only and is not intended to limit the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Except as shown in the operating examples or otherwise indicated, all numbers used in the specification and claims to express amounts, physicochemical properties, etc. of ingredients are to be understood to be adjusted in all cases by the term "about." For example, therefore, unless stated to the contrary, the numerical parameters set forth in the foregoing specification and appended claims are approximations, and those skilled in the art will be able to seek to obtain the desired properties using the teachings disclosed herein, as appropriate. Change these approximations. The use of numerical ranges expressed by endpoints includes all numbers within that range and any range within that range, for example, 1 to 5 includes 1, 1.1, 1.3, 1.5, 2, 2.75, 3, 3.80, 4, and 5, etc. .

It can be understood that the surface of traditional copper composite current collectors is relatively flat and smooth, making it difficult to coat more battery active materials on the surface, and the coating quality is poor. To this end, the present invention provides a method for preparing a copper composite current collector. This method regulates the temperature of the copper plating roller so that it has different temperature zones, thereby increasing the plating speed of the copper metal layer on the surface of the polymer film. Different growth rates of copper crystals in the copper metal layer are different to form a hole structure on the surface of the copper metal layer. The formation of the pore structure increases the roughness and specific surface area of the copper composite current collector (at least an increase of 20% compared to traditional copper composite current collectors), thereby increasing the contact between the active material and the copper composite current collector in the battery. area, increases the coating amount of active materials (at least 5% increase compared to traditional copper composite current collectors), and can reduce the internal resistance of the battery, increase the battery capacity and energy density, and extend the cycle life of the battery.

On the one hand, the present invention relates to a preparation method of a copper composite current collector, which includes the following steps:

Provide polymer films;

Using vacuum evaporation technology, the above-mentioned polymer film is passed through a copper plating roller, wherein along the axial direction of the copper plating roller, the copper plating roller has a first temperature zone and a second temperature zone, and the temperature of the first temperature zone is 40 ℃～50℃, the temperature of the second temperature zone is 10℃～20℃; and

Metallic copper is evaporated under vacuum conditions to plate copper metal layers on both sides of the polymer film.

In some embodiments, the temperature of the first temperature zone can be any value between 40°C and 50°C, for example, it can also be 41°C, 42°C, 43°C, 44°C, 45°C, 46°C, or 47°C. , 48℃, 49℃.

In some embodiments, the temperature of the second temperature zone can be any value between 10°C and 20°C, for example, it can also be 11°C, 12°C, 13°C, 14°C, 15°C, 16°C, 17°C , 18℃, 19℃.

In some embodiments, the copper plating roller has a first temperature zone and a length of the second temperature zone that are independently any value between 5 mm and 10 mm, for example, they may also be 6 mm, 7 mm, 8 mm, or 9 mm.

In some embodiments, the vacuum degree of evaporating metallic copper can be 10 ^-4 Pa to 10 ^-5 Pa, the temperature can be 1600°C to 1800°C, and the concentration of copper vapor is maintained at 60 mol/L to 80 mol/L.

In some embodiments, during the process of plating the copper metal layer, the movement speed of the polymer film can be 10m/min～100m/min, or can also be 20m/min, 30m/min, 40m/min, 50m/min, 60m/min, 70m/min, 80m/min, 90m/min.

In some embodiments, the copper metal layer has a purity of ≥99.8%.

In some embodiments, the material of the polymer film is not limited, and any polymer material known in the art can be used, including, but not limited to, composites of insulating polymer materials and inorganic non-conductive fillers, insulating polymer materials and conductive fillers, insulating polymer materials or conductive polymer materials, wherein the mass percentage of insulating polymer materials in the composite formed of insulating polymer materials and inorganic non-conductive fillers is ≥90%, insulating polymer materials and The mass percentage of the insulating polymer material in the composite formed by the conductive filler is ≥90%.

In some embodiments, the insulating polymer material may be selected from cellulose and its derivatives, starch and its derivatives, proteins and its derivatives, polyvinyl alcohol and its cross-linked polymers, polyethylene glycol and its cross-linked Polymer, polyamide, polyterephthalate, polyimide, polyethylene, polypropylene, polystyrene, polyvinyl chloride, aramid, polyphenylenediamide, acrylonitrile-butadiene -Styrene copolymer, polyethylene terephthalate, polybutylene terephthalate, poly(p-phenylene terephthalamide), polypropylene, polyformaldehyde, epoxy resin, phenolic resin, One or more of polytetrafluoroethylene, polyvinylidene fluoride, silicone rubber and polycarbonate.

In some embodiments, the conductive polymer material may be selected from doped polysulfide nitride and/or doped polyacetylene.

In some embodiments, the inorganic non-conductive filler may be selected from one or more of ceramic materials, glass materials and ceramic composite materials.

In some embodiments, the conductive filler may be selected from the group consisting of carbon black, carbon nanotubes, graphite, acetylene black, graphene, nickel, iron, copper, aluminum, alloys, nickel-coated graphite powder, and nickel-coated carbon fiber. one or more. The alloy may include one or more of nickel, iron, copper and aluminum.

In some embodiments, after plating copper metal layers on both sides of the polymer film, a step of winding is further included;

Optionally, the winding tension may be 5N to 25N.

In one aspect, the present invention also provides a copper composite current collector, which is prepared by the above-mentioned preparation method of a copper composite current collector.

In some embodiments, the copper composite current collector has at least one of the following properties:

(1) Surface roughness＞0.2μm;

(2) Specific surface area >20m ² /g;

(3) The number of surface pores is >10/m ² and the pore diameter is ≥10nm;

(4) Puncture strength ≥200gf;

(5) Longitudinal (MD) tensile strength ≥ 150MPa, longitudinal (MD) elongation ≥ 10%, transverse (TD) tensile strength ≥ 150Mpa, transverse (TD) elongation ≥ 10%.

In some embodiments, the specific surface area of the copper composite current collector can also be 25m ² /g, 28m ² /g, 30m ² /g, 35m ² /g, and the number of surface pores is >100/m ² , for example, it can also be 150 pieces/m ² , 200 pieces/m ² , 300 pieces/m ² , 400 pieces/m ² , 500 pieces/m ² .

In some embodiments, the thickness of the copper composite current collector may be 1.6 μm ~ 31 μm. Preferably, the thickness of the polymer film may be 1 μm ~ 25 μm, and the thickness of the copper metal layer may be 0.3 μm ~ 3 μm. More preferably, the thickness of the polymer film is 2 μm to 8 μm. Regulating the thickness of the polymer film within this range can not only reduce the production cost of copper composite current collectors, but also avoid the problem of polymer film breakage during processing.

In some embodiments, the polymer film meets at least one of the following properties:

(1)Puncture strength ≥200gf;

(2) Longitudinal (MD) tensile strength ≥ 160MPa, longitudinal (MD) elongation ≥ 30%, transverse (TD) tensile strength ≥ 160Mpa, transverse (TD) elongation ≥ 30%.

In another aspect, the present invention further provides a negative electrode, which includes the above-mentioned copper composite current collector and a negative electrode active material layer located on one or both sides of the copper composite current collector.

In some embodiments, the material of the negative active material layer is not limited and can be composed of commonly used negative active materials, conductive agents, and negative binders; wherein the negative active material can be graphite, lithium titanate, or lithium, The negative electrode binder may be at least one of styrene-butadiene latex, acrylate, and sodium carboxymethyl cellulose, and the conductive agent may be at least one of carbon nanotubes and conductive carbon black.

In yet another aspect, the present invention provides a lithium ion battery, which includes the above-mentioned negative electrode.

In some embodiments, a lithium-ion battery may also include a positive electrode and an electrolyte.

The positive electrode includes a positive electrode current collector and a positive electrode active material layer located on the surface of the positive electrode current collector. The positive electrode current collector can be an aluminum current collector. The material of the positive electrode active material layer is not limited and can be made of commonly used positive electrode active materials, It is composed of conductive agent and positive electrode binder; among which, the positive electrode active material can be any positive electrode active material commonly used in this field, such as lithium cobalt oxide, lithium iron phosphate, NCA, NCM, lithium manganate, lithium nickelate, NCMA or cobalt-free Positive electrode; the positive electrode binder can be at least one of PVDF and acrylate, and the conductive agent can be at least one of carbon nanotubes and conductive carbon black;.

In some embodiments, the electrolyte can be a solid electrolyte, a semi-solid electrolyte or a liquid electrolyte, wherein the solid electrolyte and semi-solid electrolyte can be an oxide or sulfide electrolyte, and the solute in the liquid electrolyte can be lithium hexafluorophosphate.

In some embodiments, the above-mentioned lithium ion battery may further include a separator, wherein the separator may be any separator known in the art, such as a PE wet separator, a PP dry separator or a double-layer PE/PP coated separator.

The shape of the lithium-ion battery is not limited, and may be cylindrical or square, for example.

In another aspect, the present invention provides an electrical device that uses the above-mentioned lithium-ion battery as a power source.

In some embodiments, specific types of electrical devices include, but are not limited to, mobile terminals (mobile phones, mobile computers, etc.), smart wearables, power tools (electric drills, electric motors, etc.), electric vehicles, mobile power supplies, etc.

The present invention will be further described in detail below with reference to specific examples and comparative examples.

Example 1

1. Preparation of copper composite current collector

A copper composite current collector was prepared using a vacuum evaporation process, and the polymer film was a biaxially oriented polypropylene (BOPP) film. Specific steps are as follows:

1) After evacuating the evaporation chamber of the vacuum ion evaporation equipment to a vacuum degree of 10 ^-5 Pa, pass the BOPP film with a thickness of 4 μm through a copper plating roller, where the copper plating roller has a first temperature of 45°C. zone and a second temperature zone with a temperature of 15°C, and the lengths of the copper plating rollers with the first temperature zone and the second temperature zone are both 6 mm;

2) Evaporate copper metal with a purity of 99.9% in the evaporation boat at 1800°C, maintain the concentration of copper vapor at 70 mol/L, and evaporate a copper metal layer with a thickness of 1 μm on both sides of the BOPP film in step 1), where , During the evaporation process, the movement speed of the BOPP film is 30m/min. The BOPP film with a copper metal layer evaporated was then rolled up under a tension of 5N and unrolled under 20N to prepare a copper composite current collector. The measured surface morphology of the copper composite current collector is shown in Figure 1, and the measured related properties of the copper composite current collector are shown in Table 1.

2. Battery assembly

Positive electrode: lithium iron phosphate;

Negative electrode: composed of the copper composite current collector prepared in step 1 and a graphite layer located on the surface of the copper composite current collector;

Electrolyte: liquid electrolyte with lithium hexafluorophosphate as solute;

Separator: polyethylene (PE) microporous separator;

Assemble the above components into a 100Ah ternary lithium-ion battery, and conduct relevant performance tests. The test results are shown in Table 2.

Example 2

The preparation method of this embodiment is basically the same as that of Example 1, except that the temperature of the copper plating roller and the copper metal evaporation parameters are different. Specific steps are as follows:

A copper composite current collector was prepared using a vacuum evaporation process, and the polymer film was a biaxially oriented polypropylene (BOPP) film. Specific steps are as follows:

1) After evacuating the evaporation chamber of the vacuum ion evaporation equipment to a vacuum degree of 10 ^-5 Pa, pass the BOPP film with a thickness of 4 μm through a copper plating roller, where the copper plating roller has a first temperature of 40°C. zone and a second temperature zone with a temperature of 10°C, and the lengths of the copper plating rollers with the first temperature zone and the second temperature zone are both 8 mm;

2) Evaporate copper metal with a purity of 99.9% in the evaporation boat at 1600°C, maintain the concentration of copper vapor at 60 mol/L, and evaporate a copper metal layer with a thickness of 1 μm on both sides of the BOPP film in step 1), where , During the evaporation process, the movement speed of the BOPP film is 20m/min. The BOPP film with a copper metal layer evaporated was then rolled up under a tension of 5N and unrolled under 20N to prepare a copper composite current collector.

Example 3

The preparation method of this embodiment is basically the same as that of Example 1, except that the polymer film is a polyethylene terephthalate film, the thickness of the polymer film and the thickness of the copper metal layer are different, the temperature of the copper plating roller, Copper metal evaporation parameters are different. Specific steps are as follows:

A copper composite current collector was prepared using a vacuum evaporation process, and the polymer film was a polyethylene terephthalate film. Specific steps are as follows:

1) After evacuating the evaporation chamber of the vacuum ion evaporation equipment to a vacuum degree of 10-5Pa, pass a polyethylene terephthalate film with a thickness of 6 μm through a copper plating roller, where the copper plating roller has a temperature The first temperature zone is 50°C and the second temperature zone is 20°C, and the lengths of the copper plating rollers with the first temperature zone and the second temperature zone are both 10 mm;

2) Evaporate the copper metal with a purity of 99.9% in the evaporation boat at 1800°C, and maintain the concentration of copper vapor at 80 mol/L to achieve the evaporation thickness on both sides of the polyethylene terephthalate film in step 1) It is a copper metal layer of 2 μm. During the evaporation process, the movement speed of the polyethylene terephthalate film is 80m/min. Then, the polyethylene terephthalate film evaporated with a copper metal layer was rolled up under a tension of 5N and unrolled under 20N to prepare a copper composite current collector.

Comparative example 1

1. Preparation of copper composite current collector

A copper composite current collector was prepared using a vacuum evaporation process, and the polymer film was a biaxially oriented polypropylene (BOPP) film. Specific steps are as follows:

1) After evacuating the evaporation chamber of the vacuum ion evaporation equipment to a vacuum degree of 10 ^-5 Pa, pass the BOPP film with a thickness of 4 μm through a copper plating roller, where the temperature of the copper plating roller is 30°C;

2) Evaporate copper metal with a purity of 99.9% in the evaporation boat at 1700°C, maintain the concentration of copper vapor at 150 mol/L, and evaporate a copper metal layer with a thickness of 1 μm on both sides of the BOPP film in step 1), where , During the evaporation process, the movement speed of the BOPP film is 50m/min. The BOPP film with a copper metal layer evaporated was then rolled up under a tension of 5N and unrolled under 20N to prepare a copper composite current collector. The measured relevant properties of the copper composite current collector are shown in Table 1.

2. Battery assembly

Positive electrode: lithium iron phosphate;

Negative electrode: composed of the copper composite current collector prepared in step 1 and a graphite layer located on the surface of the copper composite current collector;

Electrolyte: liquid electrolyte with lithium hexafluorophosphate as solute;

Separator: polyethylene (PE) microporous separator;

Assemble the above components into a 100Ah ternary lithium-ion battery, and conduct relevant performance tests. The test results are shown in Table 2.

Table 1

Performance test results Example 1 Comparative example 1 Thickness(μm) 6 6 Specific surface area (m ² /g) 28 10 MD elongation (%) 95 92 TD elongation (%) 90 88 Number of surface hole structures (pieces/m ² ) 500 0

Relevant performance tests of ternary lithium-ion batteries:

The peeling force test, battery internal resistance test and charge and discharge cycle performance test refer to the national standard GB18287_2000, and the test results are shown in Table 2.

1) Peeling force test: Test the peeling force between the aluminum composite current collector and the cathode active material layer in the lithium iron phosphate batteries assembled in 10 PCS Example 1 and Comparative Examples 1 to 3 respectively, and take the average value;

2) Battery internal resistance test: Test the internal resistance of 10 PCS lithium iron phosphate batteries assembled in Example 1 and Comparative Examples 1 to 3 respectively, and take the average value;

3) Charge and discharge cycle performance test: When the capacity retention rate is 80%, test 10 PCS lithium iron phosphate batteries assembled in Example 1 and Comparative Examples 1 to 3 at 1C rate charging and 1C rate discharge (1C/1C) respectively. cycle performance and take the average value.

Table 2

Test indicators Example 1 Comparative example 1 Peeling force(N/m) 35 25 Internal resistance(mΩ) 10 18 Number of charge and discharge cycles (weeks) 2000 1400

The technical features of the above embodiments can be combined in any way. To simplify the description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, All should be considered to be within the scope of this manual.

The above-mentioned embodiments only express several implementation modes of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention. It should be noted that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the scope of protection of the patent of the present invention should be determined by the appended claims.

Claims (11)

A method for preparing a copper composite current collector, which is characterized by comprising the following steps: Provide polymer films; Using vacuum evaporation technology, the polymer film is passed through a copper plating roller along the axial direction of the copper plating roller. The copper plating roller has a first temperature zone and a second temperature zone. The first temperature zone The temperature of the second temperature zone is 40°C to 50°C, and the temperature of the second temperature zone is 10°C to 20°C; and Metal copper is evaporated under vacuum conditions to plate copper metal layers on both sides of the polymer film. The method for preparing a copper composite current collector according to claim 1, wherein the lengths of the first temperature zone and the second temperature zone of the copper plating roller are independently 5 mm to 10 mm. The preparation method of copper composite current collector according to claim 1, characterized in that the vacuum degree of evaporating the metallic copper is 10 ^-4 Pa ~ 10 ^-5 Pa, the temperature is 1600 ° C ~ 1800 ° C, and the concentration of copper vapor Maintain it at 60mol/L~80mol/L. The method for preparing a copper composite current collector according to claim 3, wherein during the process of plating the copper metal layer, the movement speed of the polymer film is 10 m/min to 100 m/min. The method for preparing a copper composite current collector according to claim 1, wherein the material of the polymer film is selected from the group consisting of a composite formed of an insulating polymer material and an inorganic non-conductive filler, an insulating polymer material and a conductive filler. A composite, insulating polymer material or conductive polymer material, wherein the mass percentage of the insulating polymer material in the composite formed by the insulating polymer material and the inorganic non-conductive filler is ≥90%, and the insulating polymer The mass percentage of the insulating polymer material in the composite formed by the material and the conductive filler is ≥90%. The method for preparing a copper composite current collector according to claim 5, wherein the insulating polymer material is selected from the group consisting of cellulose and its derivatives, starch and its derivatives, protein and its derivatives, polyvinyl alcohol and Its cross-linked polymer, polyethylene glycol and its cross-linked polymer, polyamide, polyterephthalate, polyimide, polyethylene, polypropylene, polystyrene, polyvinyl chloride, aramid, Polyphenylenediamide, acrylonitrile-butadiene-styrene copolymer, polyethylene terephthalate, polybutylene terephthalate, polyphenylene terephthalamide , one or more of polypropylene, polyformaldehyde, epoxy resin, phenolic resin, polytetrafluoroethylene, polyvinylidene fluoride, silicone rubber and polycarbonate; and/or The conductive polymer material is selected from doped polysulfide nitride and/or doped polyacetylene; and/or The inorganic non-conductive filler is selected from one or more of ceramic materials, glass materials and ceramic composite materials; and/or The conductive filler is selected from one or more of carbon black, carbon nanotubes, graphite, acetylene black, graphene, nickel, iron, copper, aluminum, alloy, nickel-coated graphite powder and nickel-coated carbon fiber. . A copper composite current collector, characterized in that it is produced by the preparation method of a copper composite current collector according to any one of claims 1 to 6. The copper composite current collector according to claim 7, characterized in that the copper composite current collector has at least one of the following properties: (1) Surface roughness＞0.2μm; (2) Specific surface area >20m ² /g; (3) The number of surface pores is >10/m ² and the pore diameter is ≥10nm; (4) Puncture strength ≥200gf; (5) Longitudinal tensile strength ≥ 150MPa, longitudinal elongation ≥ 10%, transverse tensile strength ≥ 150Mpa, transverse elongation ≥ 10%. A negative electrode, characterized by comprising the copper composite current collector according to claim 7 or 8 and a negative electrode active material layer located on one or both sides of the copper composite current collector. A lithium ion battery, characterized by comprising the negative electrode according to claim 9. An electrical device, characterized in that the lithium ion battery according to claim 10 is used as a power source.

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