Composite current collector with high bonding strength

Abstract

The composite current collector with high bonding strength comprises a supporting layer and a metal layer, the metal layer is arranged on the surface of the supporting layer, the average particle size of particles of the metal layer is X, the surface density of the metal layer is K, and K / X is larger than or equal to 0.05 and larger than or equal to 0.1. According to the composite current collector, the binding force between the metal layer and the supporting layer of the composite current collector is changed mainly by changing the parameter property of the composite current collector, and the situation that other unnecessary structures are arranged on the supporting layer to affect the weight of the composite current collector is avoided. According to the composite current collector provided by the utility model, the metal layer in the range of K / X greater than or equal to 0.05 and greater than or equal to 0.1 has higher bonding force and is not easy to fall off.

Description

Technical Field

[0001] This utility model relates to the field of composite current collectors, and in particular to a composite current collector with high bonding strength. Background Technology

[0002] With the development of technology, composite current collectors have gradually attracted attention as a new generation of current collector materials. Composite current collectors have a sandwich structure, with a polymer layer in the middle and metal thin films on the top and bottom, which has better safety performance and energy density.

[0003] The main problem currently facing composite current collectors is the tendency for the metal layer to detach from the support layer. Several solutions exist to address this issue, such as patent CN118136852A, which uses magnetron sputtering after introducing conductive carbon into a polymer substrate. Compared to the bonding force between polymer and copper, the bonding force between C / polymer and copper is stronger, resulting in a more robust bond between the plated copper layer and the substrate. Another example is patent CN221176268U, which uses a locking mechanism to fix the positions of the layers within the current collector body, effectively preventing layer peeling after prolonged use. All these methods address the issue of metal layer detachment by incorporating various structures and materials into the current collector. However, these methods all increase the weight of the current collector itself, leading to an increase in the weight of the composite current collector and a reduction in the battery's energy density.

[0004] Therefore, existing technologies still need to be improved and enhanced. Utility Model Content

[0005] In view of the shortcomings of the prior art, the purpose of this utility model is to provide a composite current collector with high bonding strength.

[0006] To solve the above technical problems, the present invention adopts the following technical solution:

[0007] This invention provides a composite current collector with high bonding strength, comprising a support layer and a metal layer. The metal layer is disposed on the surface of the support layer, the average particle size of the metal layer is X, and the areal density of the metal layer is K, wherein 0.1≥K / X≥0.05.

[0008] Furthermore, in the aforementioned high-bonding-strength composite current collector, the average particle size X of the metal layer is 30nm-60nm, and the areal density K of the metal layer satisfies 2.1g / m³. 2 -3g / m 2 .

[0009] Furthermore, in the composite current collector with high bonding strength, a base layer is provided between the support layer and the metal layer.

[0010] Further, the composite current collector with high adhesive strength, the primer layer is a metal coating or a non-metal layer.

[0011] Further, the composite current collector with high adhesive strength, the primer layer is a metal coating or a non-metal layer.

[0012] Further, the composite current collector with high adhesive strength, the primer layer is a metal coating or a non-metal layer.

[0013] Further, the composite current collector with high adhesive strength, the primer layer is a metal coating or a non-metal layer.

[0014] Further, the composite current collector with high adhesive strength, the primer layer is a metal coating or a non-metal layer.

[0015] Further, the composite current collector with high adhesive strength, the primer layer is a metal coating or a non-metal layer.

[0016] Further, the composite current collector with high adhesive strength, the primer layer is a metal coating or a non-metal layer.

[0017] Compared with the prior art, the composite current collector with high adhesive strength provided by the utility model, including support layer and metal layer, the metal layer is arranged on the surface of the support layer, the average particle size of the metal layer is X, the surface density of the metal layer is K, wherein 0.1 >= K / X >= 0.05. The utility model mainly changes the binding force between the metal layer and the support layer of the composite current collector by changing the parameter property of the composite current collector, avoids setting other unnecessary structures on the support layer and further influences the weight of the composite current collector. The metal layer in the composite current collector of the utility model is in the range of 0.1 >= K / X >= 0.05, and the adhesive force is higher, and it is not easy to fall off. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings described below only constitute some of the embodiments of the present application, and for those skilled in the art, other drawings can also be obtained according to the structure shown in the drawings without creative labor.

[0019] Figure 1 The structure diagram of the composite current collector with high bonding strength provided by the present application.

[0020] Explanation of reference numerals:

[0021] Support layer 100

[0022] Undercoat layer 200

[0023] Metal layer 300 Specific implementation

[0024] The technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments only constitute some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0025] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative positional relationship, movement condition, etc. between the components in a certain specific posture (as shown in the drawings). If the specific posture changes, the directional indications also change accordingly.

[0026] In addition, if the embodiments of the present application involve descriptions such as "first", "second", etc., the descriptions of "first", "second", etc. are only for description purposes, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features with "first", "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that a person skilled in the art can realize it. When the combination of technical solutions contradicts each other or cannot be realized, it should be considered that the combination of technical solutions does not exist and is not within the scope of protection required by the present application.

[0027] For example, Figure 1The utility model provides a kind of composite current collector with high adhesive strength, including support layer 100 and metal layer 300, the metal layer 300 is arranged on the surface of the support layer 100, the average particle size of the metal layer 300 is X, the surface density of the metal layer 300 is K, wherein 0.1>=K / X>=0.05.The utility model mainly changes the binding force between the metal layer 300 and the support layer 100 of composite current collector by changing the parameter property of composite current collector, avoids setting other unnecessary structure on the support layer 100 and then influence the weight of composite current collector.The metal layer 300 in the range of 0.1>K / X>0.05 or 0.1>=K / X>=0.05 in the composite current collector of the utility model, its adhesive force is higher, and it is not easy to fall off.After many tests, the utility model person finds that the metal layer 300 in this range, its adhesive force is higher, and it is not easy to fall off.The specific principle is not clear, and the utility model person estimates that because the particle size of the metal layer 300 is in this range under this surface density condition, especially in this proportion range, the contact area between particles is maximum, the binding force with the support layer 100 and the micro-bonding force between particles are more powerful.

[0028] Further, the utility model provides a kind of composite current collector with high adhesive strength, the average particle size X of the metal layer 300 can be 30nm-60nm, the surface density K of the metal layer 300 satisfies 2.1g / m 2 -3g / m 2 .

[0029] Preferably, the mass of the metal layer 300 is less than the mass of the support layer 100, so that the total mass of the composite current collector is smaller, and the electric device using the utility model product, such as lithium battery, can be lighter in mass and higher in energy density.

[0030] Further, the utility model provides a kind of composite current collector with high adhesive strength, the support layer 100 and the metal layer 300 between being provided with primer layer 200.Further, the utility model provides a kind of composite current collector with high adhesive strength, and the primer layer 200 is metal coating or non-metal layer 300.

[0031] Further, the composite current collector with high bonding strength provided by the utility model, the surface density of the primer layer 200 is greater than the surface density of the metal layer 300. In this way, the components in the electrolyte can be prevented from penetrating into the support layer 100. When a general composite current collector is used in a battery, the components in the electrolyte penetrate into the support layer 100, the electrolyte corrodes the support layer 100 by contacting the support layer 100, and the service life of the composite current collector is easily reduced.

[0032] Further, the composite current collector with high bonding strength provided by the utility model, when the primer layer 200 is a non-metal layer, the ratio of the surface density of the primer layer 200 to the particle size of the primer layer 200 is less than the ratio of the surface density of the metal layer 300 to the particle size of the metal layer 300. In this way, the heat of the composite current collector can be conducted, and the primer layer 200 and the metal layer 300 are in close contact, the bonding force between the metal layer 300 and the primer layer 200 is increased, and the bonding force between the primer layer 200 and the support layer 100 is also increased.

[0033] Further, the composite current collector with high bonding strength provided by the utility model, the upper surface and the lower surface of the support layer 100 are provided with the metal layer 300, the ratio of the surface density of the metal layer 300 on the upper surface of the support layer 100 to the particle size of the metal layer 300 is less than the ratio of the surface density of the metal layer 300 on the lower surface of the support layer 100 to the particle size of the metal layer 300. In this way, the heat conduction of the composite current collector can be increased while the bonding force is met, that is, the temperature is conveniently conducted from one side of the composite current collector to the other side. Further, the composite current collector with high bonding strength provided by the utility model, the ratio of the surface density of the primer layer 200 on the upper surface of the support layer 100 to the particle size of the primer layer 200 is less than the ratio of the surface density of the primer layer 200 on the lower surface of the support layer 100 to the particle size of the primer layer 200. In this way, the heat conduction of the composite current collector can be further increased while the bonding force is met, that is, the temperature is conveniently conducted from one side of the composite current collector to the other side.

[0034] Further, the composite current collector with high bonding strength provided by the utility model, the thickness of the support layer 100 is 3um-8um. The thickness of the support layer 100 is low, the mass of the composite current collector can be reduced, and the safety performance is greatly improved compared with a pure metal current collector. The thickness of the primer layer 200 is 30-100nm, and the thickness of the metal layer 300 is 900-1000nm. The metal layer 300 has a thickness that can meet the requirements of the composite current collector, and the primer layer 200 has a thickness that can also be beneficial to reducing the weight.

[0035] The composite current collector can be prepared by various methods. A support layer 100 (film) is taken, and various methods are used to form a desired coating thickness on the support layer 100.

[0036] Specifically, in the first method provided by the utility model, the vacuum plating method is directly used to form the primer layer 200 and the metal layer 300 on the support layer 100, and the copper is taken as an example for the metal layer 300 in the following examples, and the copper is mainly formed on the support layer 100 by using the magnetron sputtering, that is, the support layer 100 is placed in the magnetron sputtering machine, and the plating is carried out in the vacuum magnetron sputtering equipment. By using the PVD (Physical vapor deposition) method, the equipment body vacuum and the process vacuum are controlled at certain parameters, and pure argon is introduced. Under the vacuum condition, the electrons collide with the argon atoms in the flight process, so that the argon ions and new electrons are generated; most of the electrons are constrained around the magnetic field by the constraint of the magnetic field of the magnetron sputtering target back, the argon ions accelerate to the cathode target under the action of the electric field, and hit the surface of the Cu alloy target (nickel-copper alloy target material is used in the application) with high energy, so that the target material is sputtered, and in the sputtered particles, the neutral target atoms or part of the ions are deposited on the base film to form the primer layer 200, and then the method is continuously used to sputter copper on the primer layer 200 in the magnetron sputtering machine for multiple times, so that the primer layer 200 reaches the thickness of 30-100 nm, and the metal layer 300 reaches the thickness of 900-1000 nm. Of course, in the above method, the vacuum evaporation method can also be used to form the metal layer 300 (that is, the copper layer). The metal layer 300 is formed on the primer layer 200.

[0037] Specifically, in the second method of the utility model, first, the base layer 200 is formed by magnetron sputtering, then vacuum evaporation is performed, and finally, the metal layer 300 is formed on the support layer 100 by electroplating. Magnetron sputtering refers to film plating in a vacuum magnetron sputtering device. By PVD (Physical vapor deposition) method, the device body vacuum and process vacuum are controlled at a certain parameter, and pure argon is introduced. Under vacuum conditions, electrons collide with argon atoms in the process of jumping, causing ionization to produce Ar positive ions and new electrons; most electrons are constrained around the magnetic field by the magnetic field constraint of the magnetron sputtering target back, Ar ions accelerate to the cathode target under the action of the electric field, and hit the Cu alloy target surface with high energy, causing the target material to sputter, and in the sputtering particles, neutral target atoms or part of the ions are deposited on the base film to form a thin film, which is the base layer 200 in this application. Electroplating refers to: using phosphor copper balls as anodes, placing the phosphor copper balls in an anode bag made of titanium blue, then immersing the entire anode bag in an acidic reagent (acidic sulfuric acid solution: sulfuric acid 90~170g / L, copper ions 50~160g / L, chloride ions 30~60ppm), taking the surface metal layer 300 as the cathode, and passing the surface between the liquid roller and the reagent tank. The surface is immersed in the reagent, ion migration replacement is carried out, and the surface obtains electrons to form a copper layer. The thickness of the copper accumulation layer is 900nm, and the film passes at a speed of 3~5m / min. Evaporation refers to: a physical phase deposition (PVD) method, melting the metal into a liquid state to form metal vapor, and then condensing the copper atoms in the vapor on the surface of the polymer material to deposit and grow. The vacuum evaporation link is added after magnetron sputtering, which aims to improve the deposition speed. The deposition speed of vacuum evaporation is 3-4 times that of magnetron sputtering, which can quickly make up the copper film to a suitable thickness for electroplating.

[0038] When the metal layer 300 of the utility model is an aluminum layer, the base layer 200 is preferably an aluminum oxide layer, and at the same time, the production method is preferably to first form the base layer 200 of aluminum oxide on the support layer 100 by vacuum evaporation, and then form the metal aluminum layer on the base layer 200 by vacuum evaporation. Such a production method can greatly reduce the complexity of the process and reduce the oxidation of aluminum metal during production. When producing aluminum oxide, the evaporation source uses an evaporation boat to evaporate, which can improve production efficiency and reduce the possibility of the support layer 100 being burned through by high-temperature particles. In the process of forming aluminum metal, a crucible should be used, which can improve efficiency because the thickness of aluminum is greater than that of aluminum oxide. A large amount of aluminum layer can be formed at one time by using a crucible, improving production efficiency.

[0039] When the metal layer 300 is copper, the base layer 200 is preferably a nickel-copper alloy, so that the adhesion of the metal layer 300 and the base layer 200 can be improved.

[0040] The utility model also provides corresponding experimental data, including example and comparative example, the support layer of example and comparative example all adopts PP film, and the material quality of metal layer all is metal copper. The average particle size of metal layer of example 1 is 30nm, and the surface density of metal layer is 3g / m 2 The average particle size of metal layer of example 2 is 60nm, and the surface density of metal layer is 3g / m 2 The average particle size of metal layer of comparative example 1 is 60nm, and the surface density of metal layer is 2.1g / m 2 The average particle size of metal layer of comparative example 2 is 30nm, and the surface density of metal layer is 3.5g / m 2 The average particle size of metal layer of comparative example 2 is 30nm, and the surface density of metal layer is 3.5g / m The adhesion of metal layer and support layer is tested by adhesive method, and the adhesive method is as follows: under the condition of room temperature and normal pressure, 3M double-sided adhesive tape is uniformly pasted on a stainless steel plate, then the sample to be tested is uniformly pasted on the double-sided adhesive tape, the width is 2cm, a high-tension tension testing machine is used to separate the conductive layer and the insulating layer of the sample to be tested, according to the data graph of tension and displacement, the maximum tension is read, and the read value is divided by 20 (unit N), so that the adhesion of the metal layer and the support layer, i.e. the adhesion F (N / mm) between the base material layer and the conductive layer in the composite current collector, is calculated. The experimental data are as follows:

[0041]

[0042] Therefore, the adhesion of the composite current collector of the utility model is higher.

[0043] In conclusion, the utility model provides a kind of composite current collector with high adhesive strength, including support layer and metal layer, the metal layer is arranged on the surface of the support layer, the average particle size of the metal layer is X, the area density of the metal layer is K, and wherein 0.1=K / X=0.05.The utility model mainly changes the binding force between the metal layer and the support layer of composite current collector by changing the parameter properties of composite current collector, avoids setting other unnecessary structures on the support layer and further affects the weight of composite current collector.The metal layer in the range of 0.1=K / X=0.05 in the composite current collector of the utility model has higher adhesive force and is not easy to fall off.After infinite times of test, the utility model person finds that the metal layer in this range has higher adhesive force and is not easy to fall off.The specific principle is not clear, and the utility model person estimates that it is because the particle size of the metal layer under this area density condition is in this range, especially in this proportion range, the contact area between particles is maximum, the binding force with the support layer and the micro-binding force between particles are more powerful.

[0044] And, the utility model provides a kind of composite current collector with high adhesive strength, the area density of the primer layer is greater than the area density of the metal layer.This can prevent the components in electrolyte from penetrating into the support layer, when general composite current collector is used in battery, the components in electrolyte penetrate into the support layer, electrolyte contacts the support layer and corrodes the support layer, which easily reduces the service life of composite current collector.Further, the utility model provides a kind of composite current collector with high adhesive strength, when the primer layer is non-metal layer, the ratio of the area density of the primer layer to its particle size is less than the ratio of the area density of the metal layer to its particle size.This is conducive to the heat export of composite current collector, while making the primer layer and the metal layer contact more closely, increasing the binding force of the metal layer and the primer layer, and also can increase the binding force of the primer layer and the support layer.

[0045] The above only for the preferred embodiment of the utility model, not therefore limit the patent range of the utility model, any equivalent structural transformation made in the utility model concept of the utility model, using the utility model specification and attached drawing contents, or direct / indirectly applied in other related technical fields are included in the patent protection range of the utility model.

Claims

1. A composite current collector having high adhesive strength, characterized by comprising: The support layer and the metal layer are provided, the metal layer is arranged on the surface of the support layer, the average particle size of the metal layer is X, and the area density of the metal layer is K, wherein 0.1>=K / X>=0.

05.

2. The high-adhesion composite current collector according to claim 1, wherein The average particle size X of the metal layer is 30 nm to 60 nm, and the area density K of the metal layer satisfies 2.1 g / m 2 -3 g / m 2 .

3. The high-adhesion composite current collector according to claim 2, wherein A primer layer is arranged between the support layer and the metal layer.

4. The high-adhesion composite current collector according to claim 3, wherein The primer layer is a metal coating or a non-metal layer.

5. The high-adhesion composite current collector according to claim 4, wherein The area density of the primer layer is greater than that of the metal layer.

6. The high-adhesion composite current collector according to claim 4, wherein When the primer layer is a non-metal layer, the ratio of the area density to the particle size of the primer layer is less than that of the metal layer.

7. The high-adhesion composite current collector of claim 1, wherein The upper surface and the lower surface of the support layer are both provided with the metal layer, and the ratio of the area density to the particle size of the metal layer on the upper surface of the support layer is less than that of the metal layer on the lower surface of the support layer.

8. The high-adhesion composite current collector of claim 4, wherein, The ratio of the area density to the particle size of the primer layer on the upper surface of the support layer is less than that of the primer layer on the lower surface of the support layer.

9. The high-adhesion composite current collector of claim 3, wherein, The mass of the metal layer is less than that of the support layer, the mass of the primer layer is less than that of the support layer, the thickness of the support layer is 3-8 um, the thickness of the primer layer is 30-100 nm, and the thickness of the metal layer is 900-1000 nm.

10. The high-adhesion composite current collector according to any one of claims 3-6, 8-9, wherein When the metal layer is an aluminum layer, the primer layer is an aluminum oxide layer; when the metal layer is a copper layer, the primer layer is a nickel-copper alloy layer.

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