CN106159316A - A current collector for the positive electrode of a lithium ion battery and a battery comprising the current collector - Google Patents

Abstract

The invention relates to a current collector for a lithium ion battery anode and a battery comprising the current collector, relates to a high-power lithium ion battery, and belongs to the technical field of secondary batteries. A current collector for a lithium ion battery anode comprises an aluminum foil substrate, wherein a graphene layer is deposited on at least one surface of the aluminum foil substrate by a microwave plasma chemical vapor deposition method. According to the invention, microwave plasma chemical vapor deposition is adopted, the preparation of a low-temperature graphene film can be realized, the graphene film can be suitable for modification on an aluminum foil current collector of a lithium ion battery anode, the first graphene layer and an aluminum foil substrate have good binding force, the conductivity of the current collector is increased, and the service life of an electrode is prolonged; the second graphene layer greatly improves the adhesive force of the current collector and the electrode active material, reduces the interface contact resistance of the current collector and the active material, and accordingly improves the high-power discharge capacity of the lithium ion battery.

Description

A current collector for the positive electrode of a lithium ion battery and a battery comprising the current collector

technical field

The invention relates to a current collector for the positive electrode of a lithium ion battery and a battery containing the current collector, relates to a high-power lithium ion battery, and belongs to the technical field of secondary batteries.

Background technique

Lithium-ion battery is a high-performance secondary battery, which has the advantages of high working voltage, large volume and energy density, long service life and small self-discharge, and is widely used in various digital products, mobile communication equipment and power tools and other fields. With the application of lithium-ion batteries in electric vehicles and electric vehicles, the high-speed discharge capability of lithium-ion batteries, that is, high-power batteries, is increasingly required. The conductivity of the electrode sheet directly affects the output power of the battery.

The current collector is a structure or component that collects current in a lithium-ion battery. Its main function is to gather the current generated by the active materials of the battery, provide electron channels, accelerate charge transfer, and improve the coulombic efficiency of charge and discharge. As a current collector, it needs to meet the characteristics of high electrical conductivity, good mechanical properties, light weight, internal resistance, and small contact resistance with the active material surface.

The positive electrode sheet of a lithium-ion battery is composed of a current collector and an active positive electrode material coated on its surface. The active material is added with carbon-based conductive agent and binder to make a slurry, which is coated on the surface of the current collector. As a power battery, the commonly used positive electrode collector is aluminum foil, and the commonly used positive electrode active material is safe and stable lithium iron phosphate or ternary material. However, lithium iron phosphate and ternary materials are used as positive electrode materials for high-power lithium-ion batteries, and their conductivity is insufficient. A large amount of carbon-based conductive agent needs to be added, and the binding force between the active material and the current collector is also insufficient. The high-speed discharge capacity of the battery and Life expectancy needs to be further improved.

Graphene is an elemental substance of carbon, which is an allotrope of carbon equivalent to diamond and graphite. Graphene has a perfect two-dimensional structure, which has good electronic conductivity, and it is also an ultra-light material. Coating graphene on the surface of the current collector substrate will help reduce the contact resistance between the active material layer and the current collector, improve the binding force between the current collector and the active material layer, and improve the current collection ability of the current collector and the conductivity of the electrode. Thereby improving the high-speed discharge capability of the lithium-ion battery.

The invention patent application with the publication number CN 104319364 A discloses a positive electrode sheet for reducing the DC internal resistance of the battery and a preparation method thereof. Containing nano-carbon fiber slurry coating, the above-mentioned single graphene coating is formed by coating a single graphene slurry, and the above-mentioned nano-carbon fiber-containing slurry coating is formed by containing nano-carbon fiber slurry. The nano-carbon fiber-containing slurry is a slurry formed of active materials, binders, solvents, and nano-carbon fibers. The graphene layer of the invention is formed by slurry coating.

The invention patent with the publication number CN 102208598 A discloses an electrode pole piece of a graphene-coated modified lithium secondary battery, including a current collector foil, and graphene layers are coated on both sides of the current collector foil , an electrode active material layer is coated on the graphene layer. The graphene-coated modified lithium secondary battery pole piece of the invention, the electrode pole piece comprises a current collector foil and a graphene layer coated on both sides of the current collector foil, and a graphene layer coated on the graphene layer The electrode active material layer of the obtained graphene-modified lithium secondary battery pole piece, because graphene has good electrical conductivity and thermal conductivity, therefore, the conductivity of the electrode pole piece and the overall performance of the battery are improved. The graphene layer of this invention is also formed by slurry coating.

The invention patent with the notification number 103545530 B discloses a current collector used in batteries, which includes a graphene film and a support structure, the graphene film is arranged on the surface of the support structure, and the graphene film includes at least A layer of graphene. The invention further provides a lithium ion battery using the current collector. The invention is characterized by at least one layer of graphene on the surface of the current collector and an active material layer containing carbon fibers. The graphene film is formed by slurry coating or hot pressing.

Contents of the invention

In order to solve the deficiencies of the above technical solutions, the present invention provides a method for preparing a graphene-modified current collector for the positive electrode of a lithium-ion battery and a lithium-ion battery using the current collector, which are used to improve the binding force between the current collector and the electrode active material layer And reduce the contact resistance, improve the conductivity of the positive electrode sheet of the lithium-ion battery, thereby improving the high-power discharge capacity of the lithium-ion battery.

A current collector for the positive pole of a lithium ion battery comprises an aluminum foil substrate, and a graphene layer is deposited on at least one surface of the aluminum foil substrate by a microwave plasma chemical vapor deposition method.

In order to improve the binding force between the active material layer and the positive electrode current collector and the conductivity of the current collector, the present invention adopts a microwave plasma vapor deposition method to prepare a graphene modified layer on the aluminum foil substrate to make a graphene modified lithium ion battery positive electrode The current collector and the lithium-ion battery using the current collector utilize the characteristics of high conductivity and low contact resistance of graphene to realize high-power discharge of the lithium-ion battery.

In the above technical solution, the graphene layer is deposited on one or both sides of the surface of the aluminum foil substrate by a microwave plasma chemical vapor deposition method.

Further, the microwave plasma chemical vapor deposition method is:

The method is carried out in a microwave plasma chemical vapor deposition device:

1) Place the aluminum foil substrate in the resonant cavity of the vacuum container, the aluminum foil substrate is connected to the cathode, and the vacuum container is the anode;

2) Evacuate the air in the vacuum container; at the same time, heat the aluminum foil substrate to 280-600°C;

3) At the reaction temperature and the argon pressure of 0.1-5Pa, apply a DC pulse voltage on the aluminum foil substrate to form plasma, treat the aluminum foil substrate for 10-30 minutes, and activate the surface of the aluminum foil substrate, wherein the aluminum foil substrate is applied The DC pulse voltage value is 400~600V;

4) After the aluminum foil substrate is activated, a 2.4GHz microwave and a mixed gas of hydrocarbon gas and argon gas are introduced into the resonant cavity of the vacuum container, and the temperature is kept at 280-600°C, the atmosphere pressure is 0.5Pa-10Pa, and the deposition process is carried out for 10 Minutes to 60 minutes, stop introducing microwaves and hydrocarbon gases, reduce the air pressure in the vacuum container to below 0.1Pa, and cool to room temperature with the furnace to obtain a lithium-ion battery cathode current collector with a graphene layer deposited on the surface of the aluminum foil material.

Wherein, the hydrocarbon gas is one of methanol or ethanol gas.

In the above technical solution, the "evacuation of the air in the vacuum container" is carried out as follows: evacuate the vacuum container to below 0.1 Pa, fill it with argon to 50-70 Pa, repeat 3 times, and then evacuate to 0.1 Pa. Below Pa.

Further, preferably, the vacuum container is evacuated to 0.05-0.1 Pa, filled with argon gas to 50-70 Pa, repeated three times, and then evacuated to 0.1-5 Pa.

In all the technical proposals of the current collector for the positive electrode of the lithium ion battery described in the present invention, the surface of the aluminum foil substrate is a rough surface with asperities with a height of 0.5-5 microns.

In all the technical solutions of the current collector for the positive electrode of the lithium-ion battery in the present invention, preferably, the thickness of the aluminum foil substrate is 8 microns to 40 microns, and the thickness of the graphene layer is 0.1 microns to 20 microns.

In all the technical solutions of the current collector for the positive electrode of the lithium-ion battery in the present invention, preferably, the volume ratio of hydrocarbon gas: argon gas in the mixed gas of hydrocarbon gas and argon gas is 1:0.2˜1:2.

Another object of the present invention is to provide a method for preparing the current collector for the positive electrode of the lithium-ion battery.

A preparation method of a current collector for a positive electrode of a lithium-ion battery is a plasma chemical vapor deposition method:

The method is carried out in a microwave plasma chemical vapor deposition device:

1) Place the aluminum foil substrate in the resonant cavity of the vacuum container, the aluminum foil substrate is connected to the cathode, and the vacuum container is the anode;

2) Evacuate the air in the vacuum container; at the same time, heat the aluminum foil substrate to 280-600°C;

3) Under the reaction temperature and the argon pressure of 0.1-5Pa, apply a DC pulse voltage on the aluminum foil substrate to form a plasma treatment. The aluminum foil substrate is activated for 10 to 30 minutes to activate the surface of the aluminum foil substrate, wherein the aluminum foil substrate is applied The DC pulse voltage value is 400~600V;

4) After the aluminum foil substrate is activated, a 2.4GHz microwave and a mixed gas of hydrocarbon gas and argon gas are introduced into the resonant cavity of the vacuum container, and the temperature is kept at 280-600°C, the atmosphere pressure is 0.5Pa-10Pa, and the deposition process is carried out for 10 Minutes to 60 minutes, stop introducing microwaves and hydrocarbon gases, reduce the air pressure in the vacuum container to below 0.1Pa, and cool to room temperature with the furnace to obtain a lithium-ion battery cathode current collector with a graphene layer deposited on the surface of the aluminum foil material.

Wherein, the hydrocarbon gas is one of methanol or ethanol gas.

Still another object of the present invention is to provide a battery including the above current collector.

A lithium ion battery, the battery includes an electrode group and a non-aqueous electrolyte, the electrode group and the non-aqueous electrolyte are sealed in a battery package; the electrode group includes a positive pole, a negative pole and a separator; the positive pole includes a positive electrode collector Fluid and coated and/or filled positive electrode active material on the positive electrode current collector; the negative electrode includes the negative electrode current collector and the negative electrode active material coated and/or filled on the negative electrode current collector; the separator is polymer porous film or composite film,

The positive current collector includes an aluminum foil substrate, and a graphene layer is deposited on at least one surface of the aluminum foil substrate by microwave plasma chemical vapor deposition; the negative current collector is copper foil.

The beneficial effects of the present invention are: graphene is a kind of carbon material with SP2 hybrid two-dimensional structure, has excellent electronic conductivity, adopts microwave plasma chemical vapor deposition, can realize the preparation of low temperature graphene film, can be applicable to The aluminum foil current collector of the positive electrode of the lithium-ion battery is modified. The first graphene layer has a good bonding force with the aluminum foil substrate, which increases the conductivity of the current collector and improves the life of the electrode. The second graphene layer greatly improves the current collector. The adhesion of the electrode active material reduces the interface contact resistance between the current collector and the active material, thereby improving the high-power discharge capacity of the lithium-ion battery.

Description of drawings

Fig. 1 is a structural diagram of a microwave plasma vapor deposition device, and the reference signs are as follows: 101, microwave generator, 102, microwave tube, 103, air inlet, 104, plasma, 105, aluminum foil substrate, 106, substrate Bracket, 107, vacuum port, 108, DC power supply, 109, coupling regulator, 110, vacuum vessel resonant cavity, 111, vacuum vessel.

2 is a schematic diagram of a positive electrode sheet using a current collector deposited with a graphene layer, and the reference signs are as follows: 1. Current collector matrix aluminum foil, 2. Graphene layer, 3. Positive electrode active material layer.

detailed description

The following non-limiting examples can enable those skilled in the art to understand the present invention more fully, but do not limit the present invention in any way.

The test methods described in the following examples, unless otherwise specified, are conventional methods; the reagents and materials, unless otherwise specified, can be obtained from commercial sources.

The method is carried out in a microwave plasma chemical vapor deposition device. The microwave plasma chemical vapor deposition device used in the following examples has a structure as shown in Figure 1. The device includes a vacuum container 111, and the vacuum container is resonant Cavity 110, the vacuum vessel resonance cavity 110 is provided with a substrate support 106 for carrying the aluminum foil material substrate 105; the device also includes a DC power supply 108, wherein the aluminum foil material substrate 105 is connected to the cathode of the DC power supply 108, and the vacuum vessel 111 is connected to the DC power supply. The anode of the power supply 108; the vacuum container 111 is provided with an air inlet 103 for air intake, a vacuum port 107 for vacuuming and a microwave tube 102, one end of the microwave tube 102 is connected to the vacuum container 111, and the other end is connected to the microwave Generator 101. The device comprises a coupling regulator 109 for coupling the microwaves to the plasma 104 .

During the microwave plasma chemical vapor deposition process, the coupling regulator 109 is adjusted to couple the microwave to the plasma 104 to form a microwave plasma for deposition.

A preparation method of a current collector for a positive electrode of a lithium ion battery is a microwave plasma chemical vapor deposition method, and the process is as follows:

1) Place the aluminum foil substrate in the vacuum container resonant cavity 110, the aluminum foil substrate 105 is connected to the cathode, and the vacuum container 111 is the anode;

2) Vacuumize the vacuum container to 0.05-0.1Pa, fill it with argon gas to 50-70Pa, repeat 3 times, and then evacuate to 0.1-5Pa; at the same time, heat the aluminum foil substrate to 280-600°C;

3) Under the reaction temperature and the argon pressure of 0.1-5Pa, apply a DC pulse voltage on the aluminum foil substrate 105 to form a plasma 104, treat the aluminum foil substrate for 10-30 minutes, and activate the surface of the aluminum foil substrate 105, wherein the aluminum foil substrate The value of the DC pulse voltage applied on the substrate 105 is 400-600V;

4) After the aluminum foil substrate 105 is activated, a 2.4GHz microwave and a mixed gas of hydrocarbon gas and argon gas are introduced into the vacuum container resonant cavity 110 (the volume ratio of hydrocarbon gas: argon gas is 1:0.2～1:2) , keep the temperature at 280-600°C, and the atmospheric pressure at 0.5Pa-10Pa, conduct deposition treatment for 10 minutes to 60 minutes, stop introducing microwave and hydrocarbon gas, reduce the air pressure in the vacuum container 111 to below 0.1Pa, and cool with the furnace To room temperature, obtain the lithium ion battery positive electrode current collector that the graphene layer is deposited on the surface of the aluminum foil material,

Wherein, the hydrocarbon gas is one of methanol or ethanol gas.

Example 1

Preparation of graphene-modified cathode current collector:

(1) Place the cleaned and degreased 15-micron thick aluminum foil substrate in the vacuum resonance cavity of the microwave plasma equipment, connect the cathode, and the vacuum container is the anode;

(2) The vacuum container is evacuated to 0.1Pa, filled with argon to 50Pa, evacuated to 0.1Pa, and repeated 3 times; at the same time, the aluminum foil substrate is heated to a temperature of 350°C;

(3) Under 1.0Pa argon pressure, apply a DC pulse voltage of 600V to the aluminum foil, and use the formed plasma to activate the surface of the aluminum foil substrate for 20 minutes;

(4) Introduce 2.4GHz microwaves and hydrocarbon gas (mixed gas of ethanol: argon = 1:0.5) into the resonant cavity of the vacuum container, keep the reaction temperature of the resonant cavity at 380°C, and conduct the deposition process for 50 minutes at a pressure of 2Pa, then stop Introducing microwaves and hydrocarbon gas, reducing the pressure in the vacuum container to below 0.1 Pa, cooling to room temperature with the furnace, and obtaining a current collector for lithium-ion battery cathodes with graphene layers deposited on aluminum foil. The graphene layer thickness is 3.0 microns.

Preparation of positive electrode using aluminum foil current collector deposited with graphene: adding nickel-cobalt-manganese ternary positive electrode material, acetylene black, and polyvinylidene fluoride into N-methylpyrrolidone solvent at a mass ratio of 85:7:8, and mixing evenly; Coated on the prepared current collector, baked at 60°C for 30 minutes, and dried in a vacuum oven at 120°C to obtain the positive electrode sheet;

Negative electrode preparation: Add carbon-coated silicon powder with a particle size of 100-120 nanometers, acetylene black, and polyvinylidene fluoride into N-methylpyrrolidone solvent at a mass ratio of 80:10:10, mix evenly; On a 20-micron copper foil, bake at 60°C for 30 minutes, then dry in a vacuum oven at 120°C to obtain the negative electrode sheet;

After the dried positive electrode, PE/PP composite separator, and negative electrode are stacked in sequence, an electrolyte solution is added. The electrolyte solution is LiPF6/EC:DEC=1:1 (Vol), and sealed in a battery package to obtain a lithium-ion battery.

The comparative battery used the same steps and materials as in Example 1, except that the positive electrode current collector used a conventional aluminum foil current collector.

After testing, the internal resistance of the battery in Example 1 was 1.80 milliohms, and that of the comparative battery example was 4.85 milliohms, and the internal resistance of the battery in the embodiment decreased significantly.

Example 2

Preparation of graphene-modified cathode current collector:

(1) Place the cleaned and degreased 20-micron thick aluminum foil substrate in the vacuum resonance cavity of the microwave plasma equipment, connect the cathode, and the vacuum container is the anode;

(2) The vacuum container is evacuated to 0.1Pa, filled with argon to 50Pa, evacuated to 0.1Pa, and repeated 3 times; at the same time, the aluminum foil substrate is heated to a temperature of 550°C;

(3) Under 5.0Pa argon pressure, apply a DC pulse voltage of 500V to the aluminum foil, and use the formed plasma to activate the surface of the aluminum foil substrate for 20 minutes;

(4) Introduce 2.4GHz microwaves and hydrocarbon gas (ethanol: argon = 1:1 mixed gas) into the resonant cavity of the vacuum container, keep the resonant cavity reaction temperature at 500°C, and deposit for 30 minutes at a pressure of 5 Pa, then stop Introduce microwave and hydrocarbon gas, reduce the air pressure in the vacuum container to below 0.1Pa, and cool down to room temperature with the furnace to obtain a current collector for lithium ion battery positive electrode with a graphene modified layer deposited on aluminum foil. The thickness of the graphene layer is 7.3 microns.

Preparation of positive electrode using aluminum foil current collector deposited with graphene: adding nickel-cobalt-manganese ternary positive electrode material, acetylene black, and polyvinylidene fluoride into N-methylpyrrolidone solvent at a mass ratio of 85:7:8, and mixing evenly; Coated on the prepared current collector, baked at 60°C for 30 minutes, and dried in a vacuum oven at 120°C to obtain the positive electrode sheet;

Negative electrode preparation: Add carbon-coated silicon powder with a particle size of 100-120 nanometers, acetylene black, and polyvinylidene fluoride into N-methylpyrrolidone solvent at a mass ratio of 80:10:10, mix evenly; On a 20-micron copper foil, bake at 60°C for 30 minutes, then dry in a vacuum oven at 120°C to obtain the negative electrode sheet;

After the dried positive electrode, PE/PP composite separator, and negative electrode are stacked in sequence, an electrolyte solution is added. The electrolyte solution is LiPF6/EC:DEC=1:1 (Vol), and sealed in a battery package to obtain a lithium-ion battery.

After testing, the internal resistance of the battery in Example 2 was 1.65 milliohms, and the internal resistance of the battery in the comparative battery example was 4.85 milliohms, and the internal resistance of the battery in the embodiment decreased significantly.

Example 3

Preparation of graphene-modified cathode current collector:

(1) Place the cleaned and degreased 20-micron thick aluminum foil substrate in the vacuum resonance cavity of the microwave plasma equipment, connect the cathode, and the vacuum container is the anode;

(2) The vacuum container is evacuated to 0.1Pa, filled with argon to 50Pa, evacuated to 0.1Pa, and repeated 3 times; at the same time, the aluminum foil substrate is heated to a temperature of 450°C;

(3) Under 10Pa argon pressure, apply a DC pulse voltage of 550V to the aluminum foil, and use the formed plasma to activate the surface of the aluminum foil substrate for 15 minutes;

(4) Introduce 2.4GHz microwaves and hydrocarbon gas (mixed gas of ethanol: argon = 1:2) into the resonant cavity of the vacuum vessel, keep the reaction temperature of the resonant cavity at 450°C, and conduct the deposition process for 25 minutes under the pressure of 8 Pa, then stop Introduce microwave and hydrocarbon gas, reduce the air pressure in the vacuum container to below 0.1Pa, and cool down to room temperature with the furnace to obtain a current collector for lithium ion battery positive electrode with a graphene modified layer deposited on aluminum foil. The graphene layer thickness is 12 microns.

Preparation of positive electrode using aluminum foil current collector deposited with graphene: add lithium ferrous phosphate positive electrode material, acetylene black, and polyvinylidene fluoride into N-methylpyrrolidone solvent at a mass ratio of 87:8:5, and mix evenly; Spread it on the prepared current collector, bake it at 60°C for 30 minutes, and then dry it in a vacuum oven at 120°C to obtain the positive electrode sheet;

Negative electrode preparation: Add carbon-coated silicon powder with a particle size of 100-120 nanometers, acetylene black, and polyvinylidene fluoride into N-methylpyrrolidone solvent at a mass ratio of 80:10:10, mix evenly; On a 20-micron copper foil, bake at 60°C for 30 minutes, then dry in a vacuum oven at 120°C to obtain the negative electrode sheet;

After the dried positive electrode, PE/PP composite separator, and negative electrode are stacked in sequence, an electrolyte solution is added. The electrolyte solution is LiPF6/EC:DEC=1:1 (Vol), and sealed in a battery package to obtain a lithium-ion battery.

A conventional aluminum foil current collector was used to prepare a positive electrode as a comparative example, and the preparation process was the same as that of Example 3.

After testing, the internal resistance of the battery in Example 3 was 3.73 milliohms, and the internal resistance of the battery in the comparative battery example was 7.34 milliohms, and the internal resistance of the battery in the embodiment decreased significantly.

Example 4

Preparation of graphene-modified cathode current collector:

(1) Place the cleaned and degreased 30-micron thick aluminum foil substrate in the vacuum resonance cavity of the microwave plasma equipment, connect the cathode, and the vacuum container is the anode;

(2) The vacuum container is evacuated to 0.1Pa, filled with argon to 50Pa, evacuated to 0.1Pa, and repeated 3 times; at the same time, the aluminum foil substrate is heated to a temperature of 580°C;

(3) Under 3Pa argon pressure, apply a DC pulse voltage of 480V to the aluminum foil, and use the formed plasma to activate the surface of the aluminum foil substrate for 12 minutes;

(4) Introduce 2.4GHz microwave and hydrocarbon gas (mixed gas of ethanol: argon = 1:2) into the resonant cavity of the vacuum container, keep the reaction temperature of the resonant cavity at 580°C, and conduct the deposition process for 40 minutes under the pressure of 10Pa, stop Introduce microwave and hydrocarbon gas, reduce the air pressure in the vacuum container to below 0.1Pa, and cool down to room temperature with the furnace to obtain a current collector for lithium ion battery positive electrode with a graphene modified layer deposited on aluminum foil. The graphene layer thickness is 18 microns.

Preparation of a positive electrode using an aluminum foil current collector deposited with graphene: adding nickel-cobalt-aluminum ternary positive electrode material, acetylene black, and polyvinylidene fluoride to N-methylpyrrolidone solvent at a mass ratio of 88:6:6, and mixing evenly; Coated on the prepared current collector, baked at 60°C for 30 minutes, and dried in a vacuum oven at 120°C to obtain the positive electrode sheet;

Negative electrode preparation: Add carbon-coated silicon powder with a particle size of 100-120 nanometers, acetylene black, and polyvinylidene fluoride into N-methylpyrrolidone solvent at a mass ratio of 80:10:10, mix evenly; On a 20-micron copper foil, bake at 60°C for 30 minutes, then dry in a vacuum oven at 120°C to obtain the negative electrode sheet;

After the dried positive electrode, PE/PP composite separator, and negative electrode are stacked in sequence, an electrolyte solution is added. The electrolyte solution is LiPF6/EC:DEC=1:1 (Vol), and sealed in a battery package to obtain a lithium-ion battery.

After testing, the internal resistance of the battery in Example 4 was 1.58 milliohms, and the internal resistance of the battery in the comparative battery example was 4.85 milliohms, and the internal resistance of the battery in the embodiment decreased significantly.

Claims (7)

1. A current collector for the positive electrode of a lithium ion battery, characterized in that: it comprises an aluminum foil substrate, and on at least one surface of the aluminum foil substrate, a graphene layer is deposited by a microwave plasma chemical vapor deposition method. 2. The current collector according to claim 1, characterized in that: the microwave plasma chemical vapor deposition method is: The method is carried out in a microwave plasma chemical vapor deposition device: 1) The aluminum foil substrate is placed in the vacuum vessel resonant cavity of the microwave plasma chemical vapor deposition device, the aluminum foil substrate is connected to the cathode, and the vacuum vessel is the anode; 2) Evacuate the air in the vacuum container; at the same time, heat the aluminum foil substrate to 280-600°C; 3) At the reaction temperature and the argon pressure of 0.1-5Pa, apply a DC pulse voltage on the aluminum foil substrate to form plasma, treat the aluminum foil substrate for 10-30 minutes, and activate the surface of the aluminum foil substrate, wherein the aluminum foil substrate is applied The DC pulse voltage value is 400~600V; 4) After the aluminum foil substrate is activated, a 2.4GHz microwave and a mixed gas of hydrocarbon gas and argon gas are introduced into the resonant cavity of the vacuum container, and the temperature is kept at 280-600°C, the atmosphere pressure is 0.5Pa-10Pa, and the deposition process is carried out for 10 Minutes to 60 minutes, stop introducing microwaves and hydrocarbon gases, reduce the air pressure in the vacuum container to below 0.1Pa, and cool to room temperature with the furnace to obtain a lithium-ion battery cathode current collector with a graphene layer deposited on the surface of the aluminum foil material. Wherein, the hydrocarbon gas is one of methanol or ethanol gas. 3. The current collector according to claim 1 or 2, characterized in that: the surface of the aluminum foil substrate is a rough surface with asperities with a height of 0.5-5 microns. 4 . The current collector according to claim 1 , wherein the thickness of the aluminum foil substrate is 8 microns to 40 microns, and the thickness of the graphene layer is 0.1 microns to 20 microns. 5 . The current collector according to claim 2 , wherein the volume ratio of hydrocarbon gas: argon gas in the mixture gas of hydrocarbon gas and argon gas is 1:0.2˜1:2. 6. A lithium ion battery, characterized in that: the current collector of the positive electrode used is the current collector according to claim 1. 7. The battery according to claim 6, characterized in that: the battery comprises an electrode group and a non-aqueous electrolyte, and the electrode group and the non-aqueous electrolyte are sealed in a battery pack; the electrode group comprises a positive pole, a negative pole and separator; the positive electrode includes a positive electrode current collector and coating and/or filling the positive electrode active material on the positive electrode current collector; the negative electrode includes a negative electrode current collector and coating and/or filling the negative electrode active material on the negative electrode current collector ; The diaphragm is a porous polymer membrane or a composite membrane.