WO2023115817A1

WO2023115817A1 - Composite current collector, manufacturing method therefor, electrode sheet thereof, and battery

Info

Publication number: WO2023115817A1
Application number: PCT/CN2022/095463
Authority: WO
Inventors: 庄志; 刘洋; 蔡裕宏; 郭桂略; 虞少波; 李恒; 程跃
Original assignee: 上海恩捷新材料科技有限公司
Priority date: 2021-12-22
Filing date: 2022-05-27
Publication date: 2023-06-29
Also published as: CN114284504A; CN114284504B

Abstract

The present invention relates to the field of batteries. Specifically disclosed is a composite current collector, comprising an insulating layer and a conductive layer, wherein the insulating layer is used for bearing the conductive layer; the conductive layer is used for bearing an electrode active material, and the conductive layer is located on at least one surface of the insulating layer; and the surface of the insulating layer is rough and comprises burrs. According to the composite current collector manufactured in a reactive ion etching (RIE) mode, laser drilling is not needed, so that the cost can be reduced, the reliability is improved, and the service life is prolonged; moreover, in a temperature rise stage caused by overshoot and short circuit, the composite current collector causes the insulating layer to be fused or expanded, and the conductive layer becomes discontinuous, so that the resistance is rapidly increased, the current is rapidly reduced, and the generation of joule heat is inhibited, thereby being capable of effectively reducing the local temperature bulge caused by the short circuit in a battery, and reducing the risks of ignition and explosion of a lithium ion battery.

Description

Composite current collector and its preparation method, its pole piece and battery

cross reference

This application claims the priority of Chinese patent application number 2021115834792 filed on December 22, 2021. The content of the above application is incorporated herein by reference.

technical field

The invention relates to the field of batteries, in particular to a composite current collector, a preparation method thereof, a pole piece thereof and a battery.

Background technique

Lithium-ion batteries have the advantages of high energy density, high output power, and long cycle life, and are widely used in electric vehicles and consumer electronics products. However, in recent years, safety accidents caused by fire or explosion of lithium-ion batteries have emerged one after another, seriously endangering people's normal life. Therefore, the safety issue of lithium-ion batteries has attracted extensive attention of scientific researchers.

Many experimental results have shown that the local temperature surge caused by the short circuit in the battery is the culprit of the fire and explosion of the lithium-ion battery. In order to avoid the internal short circuit inside the battery, researchers have tried many solutions, among which improving the structure design of the current collector is considered to be a very effective solution.

Currently, a new current collector structure has been reported in which a metal layer is carried on a PPTC (polymer-based positive temperature coefficient material) material layer, the metal layer is used to carry an electrode active material layer, and the metal layer is located on at least one surface. The new current collector with this structure can effectively reduce the local temperature surge caused by the short circuit in the battery, and reduce the risk of fire and explosion of the lithium-ion battery. However, since the conductive layer and the insulating layer of this new type of current collector are respectively metal and polymer, the conductive layer is easy to fall off from the insulating layer during processing, thereby affecting the reliability and service life of the current collector. Although the peel strength can be improved by using laser drilling in the thickness direction of the insulating layer, laser drilling will cause two adverse effects. First, laser drilling will greatly increase the manufacturing cost, so it is unfavorable for the promotion and use of this new type of current collector; second, laser drilling will also destroy the continuity of the polymer insulating layer and increase its brittleness, making this type of current collector The tensile strength and processability of the novel current collector are reduced. In addition, some people deposit a layer of Ni, Ti, Ta and other metals on the surface of the polymer film in order to increase the bonding force between the polymer film and the conductive layer. However, due to the high price of precious metals, this method will also greatly increase the manufacturing cost and is not suitable for application in real production.

Therefore, it is necessary to provide a current collector with low cost and high peel strength.

Contents of the invention

In order to achieve the above object, technical solution of the present invention is achieved in that way:

The object of the present invention is to provide a composite current collector, comprising an insulating layer and a conductive layer, the insulating layer is used to carry the conductive layer; the conductive layer is used to carry electrode active materials, and the conductive layer is located on the insulating layer. on at least one surface of the insulating layer; the surface of the insulating layer is rough and contains burrs.

Further, the material of the insulating layer is selected from polyamide (Polyamide, referred to as PA), polyethylene terephthalate (Polyethylene terephthalate, referred to as PET), polyimide (Polyimide, referred to as PI), polyethylene (Polyethylene , referred to as PE), polypropylene (Polypropylene, referred to as PP), polystyrene (Polystyrene, referred to as PS), polyvinyl chloride (Polyvinyl chloride, referred to as PVC), acrylonitrile - butadiene - styrene copolymer (Acrylonitrile butadiene styrene copolymer) copolymers, referred to as ABS), polybutylene terephthalate (Polybutylene terephthalat, referred to as PBT), poly-p-phenylene terephthalamide (Poly-p-phenylene terephthalamide, referred to as PPA), epoxy resin (epoxy resin), polyformaldehyde (Polyformaldehyde, referred to as POM), phenolic resin (Phenol-formaldehyde resin), polypropylene (referred to as PPE), polytetrafluoroethylene (Polytetrafluoroethylene, referred to as PTFE), silicone rubber (Silicone rubber), polyvinylidene fluoride (Polyvinylidenefluoride, referred to as PVDF), polycarbonate (Polycarbonate, referred to as PC) at least one.

Further, the material of the conductive layer is selected from at least one of metal conductive materials and carbon-based conductive materials; the metal conductive materials are preferably aluminum, copper, nickel, titanium, silver, nickel-copper alloy, aluminum-zirconium alloy At least one of the carbon-based conductive materials is preferably at least one of graphite, acetylene black, graphene, and carbon nanotubes.

Further, the thickness of the insulating layer is 1-20 μm, preferably 2-10 μm, 2-6 μm, 3-5 μm, 4-5 μm.

Further, the thickness of the conductive layer is 0.05-10 μm, preferably 0.1-5 μm, 0.25-2 μm, 0.5-1.5 μm, 1-2 μm.

Further, the size range of the burr is between 25-2000nm, preferably 25-500nm, 30-150nm, 30-130nm, 30-100nm, 30-80nm, 30-60nm, 30-50nm, 30-40nm .

Here, when the size of the burr is greater than 2000nm, it may exceed the thickness of the conductive layer, which is meaningless, and if it is too large, it cannot play the role of anchoring. When the size of the burr is too small, less than 25nm, it is difficult to play an anchoring role.

Further, the structure of the burr is that the end away from the surface of the insulating layer is thicker than the end contacting the surface of the insulating layer, and it is bent.

Further, the peel strength of the composite current collector is above 180N/m, preferably above 220N/m, above 225N/m, above 250N/m, above 275N/m, above 330N/m, above 350N/m, Above 370N/m, above 450N/m, above 550N/m, above 720N/m, above 810N/m, above 880N/m, above 990N/m.

Further, the conductive layer is located on both surfaces of the insulating layer.

Another object of the present invention is to provide a composite current collector, comprising an insulating layer, a conductive layer and an electroplating layer, the insulating layer is used to carry the conductive layer; the conductive layer is located on at least one surface of the insulating layer; The electroplating layer is used to carry electrode active materials, and the electroplating layer is located on the other side of the conductive layer away from the insulating layer and/or the insulating layer is away from the other side of the conductive layer; the insulating layer The surface is rough and contains burrs.

Further, the material of the conductive layer or the electroplating layer is selected from at least one of aluminum, copper, nickel, titanium, silver, nickel-copper alloy, and aluminum-zirconium alloy.

Further, the material of the insulating layer is selected from polyamide, polyethylene terephthalate, polyimide, polyethylene, polypropylene, polystyrene, polyvinyl chloride, acrylonitrile-butadiene-styrene Copolymer, polybutylene terephthalate, polyparaphenylene terephthalamide, epoxy resin, polyoxymethylene, phenolic resin, polypropylene, polytetrafluoroethylene, silicone rubber, polyvinylidene fluoride, at least one of polycarbonates.

Further, the thickness of the electroplating layer is 0.25-2 μm, preferably 0.5-1.5 μm, 0.75-1 μm.

Another object of the present invention is to provide a method for preparing a composite current collector, comprising the following steps:

(1) Forming a burr-like microstructure on the surface of the insulating layer by reactive ion etching;

(2) A conductive layer is formed on at least one surface of the insulating layer with burrs by vapor deposition or electroless plating.

Further, the vapor deposition method in step (2) is a physical vapor deposition method or a chemical vapor deposition method; the physical vapor deposition method is at least one of vacuum evaporation, thermal evaporation, electron beam evaporation, and sputtering A sort of.

Furthermore, the sputtering method is a magnetron sputtering method.

Further, the power during the reactive ion etching is controlled between 10-200W, preferably 10-100W, 10-50W.

Further, the reaction time during the reactive ion etching is controlled between 10-120s, preferably 30-120s, 30-90s, 10-60s, 10-50s, 10-30s.

Further, the type of reactive ions in reactive ion etching is one or a gas mixture of two or more of oxygen, helium, argon, krypton, ammonia, nitrous oxide, carbon dioxide, and carbon tetrafluoride.

(2) forming a conductive layer on at least one surface of the insulating layer with burrs by vapor deposition or electroless plating;

(3) Perform electroplating on the other side of the conductive layer away from the insulating layer and/or on the other side of the insulating layer away from the conductive layer to form an electroplating layer.

Another object of the present invention is to provide a pole piece, comprising any of the above composite current collectors and an electrode active material layer formed on the surface of the composite current collector.

Another object of the present invention is to provide a battery, including a positive pole piece, a separator and a negative pole piece, and the positive pole piece and/or the negative pole piece are the pole pieces provided for the above purpose.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The composite current collector prepared by the present invention will cause the insulating layer to fuse or bulge during the temperature rise stage caused by overshoot and short circuit, and the conductive layer will become discontinuous, so the resistance increases rapidly and the current decreases rapidly, which suppresses the The generation of Joule heat can effectively reduce the local temperature surge caused by the short circuit in the battery, and reduce the risk of fire and explosion of lithium-ion batteries;

(2) The composite current collector prepared by the present invention can greatly reduce the thickness of the conductive layer (that is, the metal layer), reduce the probability of burrs on the metal layer, and thereby reduce the risk of short circuit;

(3) The composite current collector prepared by the present invention is light in weight, which will increase the gravimetric energy density of the battery (the weight of the current collector is reduced by 128.57%, calculated according to PET-1.40g/cm3; Cu-8.96g/cm3);

(4) The present invention improves the roughness of the surface of the insulating layer by means of reactive ion etching (RIE). After the conductive layer is deposited, the peeling strength between it and the insulating layer will be greatly improved, and laser drilling is not required, which can reduce the cost, the reliability of the composite current collector of the present invention will be improved, and the service life will be extended.

Description of drawings

Fig. 1 is the structural representation of a kind of composite current collector in the embodiment of the present invention;

Figure 2 is a schematic structural view of another composite current collector in the specific implementation of the present invention;

Fig. 3 is a structural schematic diagram of another composite current collector in the specific implementation of the present invention;

Fig. 4 is the SEM figure of polyethylene terephthalate film;

Fig. 5 is the SEM picture of the polyethylene terephthalate film after reactive ion etching treatment;

Component designation description

1. Insulation layer

2. Conductive layer

3. Burr microstructure

4. Plating layer

Detailed ways

The specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described here are only used to illustrate and explain the present invention, and are not intended to limit the present invention. The specific embodiment of the present invention provides a method for preparing a composite current collector, comprising the following steps:

S1, the formation of the insulating layer 1 on the surface of the burr-like microstructure 3

Put the insulating layer 1 (that is, the polymer film) into the cavity of the reactive ion etching equipment, by controlling the power of the equipment, the reaction time, and the type of the reactive ion, such as using argon, oxygen, nitrogen, etc., during the polymerization A burr-like microstructure 3 (as shown in FIG. 1 ) is formed on the surface of the thin film 1 of the object, and the size of the microstructure 3 is between 25nm and 2000nm. The burrs 3 are evenly or unevenly distributed on the polymer surface 1, which increases the surface roughness of the polymer film 1 and acts as a rivet. After the conductive layer 2 is deposited on the polymer film 1, the burrs 3 will fix the conductive layer 2 The role of layer 2. Therefore, the peel strength between the conductive layer 2 and the insulating layer 1 will be greatly improved.

Here, the power of the reactive ion etching equipment is controlled between 10-200W.

Here, the response time of the reactive ion etching equipment is controlled between 30 and 120 s.

Here, the gas species of the reactive ions is one or a gas mixture of two or more of oxygen, helium, argon, krypton, ammonia, nitrous oxide, carbon dioxide, and carbon tetrafluoride.

As shown in Figure 4, the surface of the original polyethylene terephthalate film 1 is flat (a-b). According to the mechanical bonding theory, after the conductive layer 2 is deposited on the surface of the polyethylene terephthalate film 1, due to the conductive Layer 2 cannot be embedded into the polyethylene terephthalate film 1, so the bonding force between the conductive layer 2 and the polyethylene terephthalate film 1 is weak, and the peel strength is low.

As shown in Figure 5, the surface of the polyethylene terephthalate film 1 after reactive ion etching is rough (c-d), and it is clearly visible that the burrs are evenly distributed on the surface of the polyethylene terephthalate film 1 , The tip of the burr 3 is thicker than the lower end, and is bent, like a barb, so it can play the role of a rivet (similar to the burr on the surface of cocklebur). According to the mechanical bonding theory, since the conductive layer 2 can be embedded inside the polyethylene terephthalate film 1, the bonding force between the polyethylene terephthalate film 1 and the conductive layer 2 is greatly improved , the peel strength of the whole new composite current collector is also increased.

S2. Formation of composite current collector

As shown in Figure 1, a conductive layer 2 is formed by vapor deposition on the two surfaces of the insulating layer 1 with burrs 3; as shown in Figure 3, electroplating is performed on the conductive layer 2 to form an electroplated layer 4; 2 Perform electroplating on the other side away from the insulating layer 1 and on the other side of the insulating layer 1 away from the conductive layer 2 to form an electroplating layer 4 .

Here, the vapor deposition method is a physical vapor deposition method or a chemical vapor deposition method;

Physical vapor deposition is preferred, and at least one of vacuum evaporation, thermal evaporation, electron beam evaporation, and sputtering is preferred, and magnetron sputtering is most preferred.

Here, the electroplating is at least one of electroless plating and ion plating.

The specific embodiment of the present invention provides a composite current collector, including an insulating layer and a conductive layer, the insulating layer is used to carry the conductive layer; the conductive layer is used to carry electrode active materials, and the conductive layer is located on the On at least one surface of the insulating layer; the surface of the insulating layer is rough and contains burrs.

The specific embodiment of the present invention provides a composite current collector, including an insulating layer, a conductive layer and an electroplating layer, the insulating layer is used to carry the conductive layer; the conductive layer is located on at least one surface of the insulating layer; the The electroplating layer is used to carry electrode active materials, and the electroplating layer is located on the other side of the conductive layer away from the insulating layer and/or on the other side of the insulating layer away from the conductive layer; the surface of the insulating layer is rough and contains burrs.

The present invention will be described in detail through specific examples below.

In the following examples and comparative examples, relevant data are determined according to the following methods:

(1) SEM

The surface morphology of the reactive ion etched samples was tested after gold spraying treatment. The purpose of spraying gold is to improve the clarity of the picture. The sprayed gold particles are very small and will not affect the shape of the burrs. The field emission scanning electron microscope (FE-SEM) was used for shooting, and the shooting was carried out under the condition of low voltage to avoid burning and destroying the burr morphology.

(2) Peel strength

a. Paste 50mm*19mm (length*width) 3M double-sided tape on the upper end of the steel plate.

b. Paste the coated surface of the diaphragm to be tested on the tape, and the diaphragm should be parallel to the steel plate.

c. Fix the lower end of the steel plate on the lower fixture, and clamp the diaphragm to be tested at the end without tape in the upper fixture.

d. According to the specified test conditions, start the testing machine according to the operating regulations of the tensile testing machine, and conduct the test.

e. After the sample is peeled off, read the maximum peel strength.

f. Test all samples to be tested according to the above steps.

(3) Burr size

Interference microscopy method: Using the principle of light wave interference, the shape error of the measured surface is displayed as an interference fringe pattern, and the microscopic part of these interference fringes is magnified by a microscope with a high magnification for measurement. This method is suitable for measurement ranges in 0.025～0.8μm.

(4) Thickness

Use the thickness gauge, turn on the main power, set the correction coefficient according to the test requirements; place the sample on the test platform, press down the probe to make it in good contact with the sample, and read the thickness result.

(5) Square resistance

Turn on the main power supply, set the correction coefficient according to the test requirements; after selecting the measurement category, switch the instrument to the measurement mode; place the sample on the test bench, press the probe down to make it in good contact with the sample, and read the test result.

Example 1

Put the polyethylene terephthalate film 1 with a thickness of 4 μm into the cavity of the reactive ion etching equipment, set the power of the equipment to 10W, the reaction time to 30s, and the type of the reactive ion to be argon, and the A burr-like microstructure 3 of 30 nm is formed on the surface of the ethylene terephthalate film 1, and a 1 μm thick copper layer 2 is chemically plated on one surface thereof, and the peel strength between the surface and the copper layer 2 is shown in Table 1 .

Example 2

The power of the equipment in Example 1 is adjusted to 50W, and all the other remain unchanged. On the surface of the polyethylene terephthalate film 1, a burr-like microstructure 3 of 40nm is formed, and then a 1 μm thick microstructure is electrolessly plated on one of its surfaces. The copper layer 2, test the peel strength between the surface and the copper layer 2 as shown in Table 1.

Example 3

The power of equipment in embodiment 1 is adjusted to 100W, all the other remain unchanged, form the burr shape microstructure 3 of 60nm on the surface of polyethylene terephthalate film 1, go up 1 μ m thick on one surface chemical plating again The copper layer 2, test the peel strength between the surface and the copper layer 2 as shown in Table 1.

Example 4

The power of the equipment in Example 1 is adjusted to 200W, and all the other remain unchanged. On the surface of the polyethylene terephthalate film 1, a burr-like microstructure 3 of 80nm is formed, and then one of its surfaces is chemically plated with a thickness of 1 μm. The copper layer 2, test the peel strength between the surface and the copper layer 2 as shown in Table 1.

Example 5

Put the polyethylene terephthalate film 1 with a thickness of 4 μm into the cavity of the reactive ion etching equipment, set the power of the equipment to 100W, the reaction time to 30s, and the type of the reactive ion to be oxygen, and the polyethylene terephthalate film A 50nm burr-like microstructure 3 is formed on the surface of the ethylene glycol phthalate film 1, and a 1 μm thick copper layer 2 is sputtered on one surface thereof, and the peel strength between the surface and the copper layer 2 is tested as shown in Table 1 .

Example 6

The reaction time in embodiment 5 is adjusted to 60s, all the other remain unchanged, form the burr-like microstructure 3 of 80nm on the surface of polyethylene terephthalate film 1, sputter on its one surface again thick 1 μm Copper layer 2, test the peel strength between the surface and copper layer 2 as shown in Table 1.

Example 7

The reaction time in embodiment 5 is adjusted to 90s, all the other remain unchanged, on the surface of polyethylene terephthalate film 1, form the burr-like microstructure 3 of 100nm, sputter on one surface of it again thick 1 μm Copper layer 2, test the peel strength between the surface and copper layer 2 as shown in Table 1.

Example 8

The reaction time in embodiment 5 is adjusted to 120s, all the other remain unchanged, form the burr-like microstructure 3 of 130nm on the surface of polyethylene terephthalate film 1, sputter on its one surface again thick 1 μm Copper layer 2, test the peel strength and sheet resistance between the surface and copper layer 2 as shown in Table 1.

Example 9

In Example 8, a copper layer 4 with a thickness of 0.75 μm was electroplated on the other surface away from the side of the copper layer 2 that is in contact with the sputtering of the polyethylene terephthalate film, and its sheet resistance was tested as shown in Table 1.

Example 10

In Example 8, a copper layer 4 with a thickness of 1 μm was electroplated on the other surface away from the side of the copper layer 2 that is in contact with the sputtering of the polyethylene terephthalate film, and its sheet resistance was tested as shown in Table 1.

Example 11

The reaction time in embodiment 5 is adjusted to 150s, all the other remain unchanged, form the burr-like microstructure 3 of 150nm on the surface of polyethylene terephthalate film 1, sputter on one surface of it again thick 1 μm Copper layer 2, test the peel strength between the surface and copper layer 2 as shown in Table 1.

Example 12

Put the polyethylene terephthalate film 1 with a thickness of 4 μm into the cavity of the reactive ion etching equipment, set the power of the equipment to 100W, the reaction time to 120s, and the type of the reactive ion to be oxygen, and the polyethylene terephthalate film A 130nm burr-like microstructure 3 is formed on the surface of the ethylene glycol phthalate film 1, and then a 2 μm thick aluminum layer 2 is vacuum-deposited on one of its surfaces, and the peel strength between the surface and the aluminum layer 2 is tested as shown in the table 1.

Example 13

Put the polyethylene film 1 with a thickness of 4 μm into the cavity of the reactive ion etching equipment, set the power of the equipment to 100W, the reaction time to 30s, and the type of the reactive ion to be oxygen to form a 50nm layer on the surface of the polyethylene film 1. The burr-like microstructure 3 was sputtered on one surface of the copper layer 2 with a thickness of 1 μm, and the peel strength between the surface and the copper layer 2 was tested as shown in Table 1.

Comparative example 1

A copper layer 2 with a thickness of 1 μm was sputtered on a surface of a polyethylene terephthalate film 1 with a thickness of 4 μm, and the peel strength between the surface and the copper layer 2 was tested as shown in Table 1.

Comparative example 2

A 2 μm thick aluminum layer 2 was vacuum-evaporated on a surface of a polyethylene terephthalate film 1 with a thickness of 4 μm, and the peel strength between the surface and the aluminum layer 2 was tested as shown in Table 1.

Table 1 Test parameters and performance comparison table of Examples 1-12 and Comparative Examples 1-2

The above content related to common knowledge will not be described in detail, and those skilled in the art can understand it. The size of the burr-like microstructure mentioned in this article is the average value of many burr sizes.

The above descriptions are only some specific embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of the present invention. within the scope of protection. The technical scope of the present invention is not limited to the content in the specification, but must be determined according to the scope of the claims.

Claims

A composite current collector, characterized in that: it includes an insulating layer and a conductive layer, the insulating layer is used to carry the conductive layer; the conductive layer is used to carry electrode active materials, and the conductive layer is located on the insulating layer on at least one surface of the insulating layer; the surface of the insulating layer is rough and contains burrs.
The composite current collector according to claim 1, characterized in that: the material of the insulating layer is selected from polyamide, polyethylene terephthalate, polyimide, polyethylene, polypropylene, polystyrene, poly Vinyl chloride, acrylonitrile-butadiene-styrene copolymer, polybutylene terephthalate, poly-p-phenylene terephthalamide, epoxy resin, polyoxymethylene, phenolic resin, polypropylene, poly At least one of tetrafluoroethylene, silicone rubber, polyvinylidene fluoride, and polycarbonate.
The composite current collector according to claim 1, characterized in that: the material of the conductive layer is selected from at least one of metal conductive materials and carbon-based conductive materials.
The composite current collector according to claim 1, characterized in that: the size range of the burrs is between 25-500 nm.
The composite current collector according to claim 1, characterized in that: the structure of the burr is that the end away from the surface of the insulating layer is thicker than the end contacting the surface of the insulating layer, and the burrs are bent.
The composite current collector according to claim 1, wherein the peel strength of the composite current collector is above 180 N/m.
The composite current collector according to claim 3, wherein the metal conductive material is selected from at least one of aluminum, copper, nickel, titanium, silver, nickel-copper alloy, and aluminum-zirconium alloy.
The composite current collector according to claim 4, characterized in that: the size range of the burr is between 30nm and 130nm.
The composite current collector according to claim 6, characterized in that the peel strength of the composite current collector is above 450 N/m.
A composite current collector, characterized in that: comprising an insulating layer, a conductive layer and an electroplating layer, the insulating layer is used to carry the conductive layer; the conductive layer is located on at least one surface of the insulating layer; the electroplating layer is used to carry the electrode active material, and the electroplating layer is located on the other side of the conductive layer away from the insulating layer and/or on the other side of the insulating layer away from the conductive layer; the surface of the insulating layer is rough and contain burrs.
The composite current collector according to claim 10, characterized in that: the material of the conductive layer or the electroplating layer is selected from at least one of aluminum, copper, nickel, titanium, silver, nickel-copper alloy, and aluminum-zirconium alloy.
A method for preparing a composite current collector, comprising the steps of:

(1) Forming a burr-like microstructure on the surface of the insulating layer by reactive ion etching;

(2) A conductive layer is formed on at least one surface of the burr-grown insulating layer by vapor deposition or electroless plating.
The preparation method of the composite current collector according to claim 12, characterized in that: the vapor deposition method in step (2) is a physical vapor deposition method or a chemical vapor deposition method; the physical vapor deposition method is a vacuum evaporation method, At least one of thermal evaporation, electron beam evaporation, and sputtering.
The method for preparing a composite current collector according to claim 12, characterized in that: the power during the reactive ion etching is controlled between 10-200W.
The preparation method of the composite current collector according to claim 12, characterized in that: the reaction time during the reactive ion etching is controlled between 10-120s.
The preparation method of the composite current collector according to claim 12, characterized in that: the type of the reactive ion during the reactive ion etching is oxygen, helium, argon, krypton, ammonia, nitrous oxide, carbon dioxide, tetrafluoro One or more gas mixtures of carbon dioxide.
A method for preparing a composite current collector, comprising the steps of:

(1) Forming a burr-like microstructure on the surface of the insulating layer by reactive ion etching;

(2) forming a conductive layer on at least one surface of the insulating layer with burrs by vapor deposition or electroless plating;

(3) Perform electroplating on the other side of the conductive layer away from the insulating layer and/or on the other side of the insulating layer away from the conductive layer to form an electroplating layer.
The method for preparing a composite current collector according to claim 17, wherein the electroplating is at least one of electroless plating and ion plating.
A pole piece, characterized in that it comprises the composite current collector according to any one of claims 1 to 11 and an electrode active material layer formed on the surface of the composite current collector.
A battery, comprising a positive pole piece, a separator and a negative pole piece, characterized in that: the positive pole piece and/or the negative pole piece are the pole pieces described in claim 19.