Corrosion-resistant nano-porous composite copper foil

Abstract

The utility model relates to lithium battery material technical field, concretely relates to a kind of corrosion-resistant nanopore composite copper foil, including first base material, first base material at least one side is sequentially provided with nanopore base material, primer layer and copper layer, nanopore base material is porous structure, the aperture of nanopore on nanopore base material is 10-20nm, the porosity of nanopore base material is 25-45%, and nanopore is bottle neck shape to form anchor point.For the neck effect of nanopore, the nanopore on the nanopore base material is contracted to form a bottle neck shape, which can maintain the adhesion provided by the copper layer anchoring, reduce the residual and penetration of sulfuric acid, and the neck structure of the nanopore makes the copper layer and the first base material and the nanopore base material form a stronger physical anchoring and chemical combination, the ability to resist thermal expansion and contraction is improved, and is suitable for more severe application environment.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery materials technology, specifically to a corrosion-resistant nanoporous composite copper foil. Background Technology

[0002] Copper foil has low surface oxygen properties, allowing it to adhere to various substrates such as metals and insulating materials, and it offers a wide operating temperature range. The use of composite copper foil is increasing, with widespread applications in lithium-ion batteries.

[0003] However, the base film of nanoporous composite copper foil generally has a nanoporous structure of 50-100 nm. The presence of residual sulfuric acid within the nanopores will continuously corrode the copper layer, eventually leading to product failure. Utility Model Content

[0004] The purpose of this invention is to solve the problem of residual sulfuric acid in the nanopores of nanoporous composite copper foil, which continuously corrodes the copper layer. The invention provides a corrosion-resistant nanoporous composite copper foil by changing the shape and pore size of the nanopores to reduce the residue and penetration of sulfuric acid.

[0005] To achieve the above objectives, the technical solution of this utility model is as follows:

[0006] A corrosion-resistant nanoporous composite copper foil includes a first substrate, wherein a nanoporous substrate, an underlayer, and a copper layer are sequentially disposed on at least one side of the first substrate. The nanoporous substrate has a porous structure, and the nanopores on the nanoporous substrate are bottleneck-shaped to form anchoring points.

[0007] Preferably, the pore size of the nanopore is 10-20 nm.

[0008] Preferably, the porosity of the nanoporous substrate is 25-45%.

[0009] Preferably, the sum of the thicknesses of the first substrate and the nanoporous substrate is 2.5-8 μm.

[0010] Preferably, the thickness of the underlayer is 10-20 nm.

[0011] Preferably, the thickness of the copper layer is 300-1000 nm.

[0012] Preferably, the copper layer includes a first copper layer attached to the surface of the underlayment and a second copper layer attached to the surface of the first copper layer.

[0013] Preferably, the thickness of the first copper layer is less than one-third of the thickness of the copper layer.

[0014] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0015] This invention utilizes the nanopore necking effect to shrink the nanopores on the nanopore substrate into a bottleneck shape. This maintains the adhesion provided by the copper layer anchoring while reducing the residue and penetration of sulfuric acid. In addition, the nanopore necking structure enables the copper layer to form a stronger physical anchoring and chemical bond with the first substrate and the nanopore substrate, improving the resistance to thermal expansion and contraction and making it suitable for more demanding application environments. Attached Figure Description

[0016] The disclosure of this utility model is illustrated with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of this utility model. In the drawings, the same reference numerals are used to refer to the same parts.

[0017] in:

[0018] Figure 1 This is a schematic diagram of the structure of this utility model.

[0019] The diagram is labeled as follows: 1. First substrate; 2. Nanoporous substrate; 3. Underlayer; 4. First copper layer; 5. Second copper layer. Detailed Implementation

[0020] It is readily understood that, based on the technical solution of this utility model, those skilled in the art can propose various interchangeable structural methods and implementations without altering the essential spirit of this utility model. Therefore, the following detailed embodiments and accompanying drawings are merely illustrative descriptions of the technical solution of this utility model and should not be considered as the entirety of this utility model or as limitations or restrictions on the technical solution of this utility model.

[0021] like Figure 1 As shown, a specific embodiment of the corrosion-resistant nanoporous composite copper foil provided by this utility model includes a nanoporous substrate 2, a base layer 3, and a copper layer sequentially disposed on both sides of the first substrate 1. The copper layer includes a first copper layer 4 attached to the surface of the base layer 3 and a second copper layer 5 attached to the surface of the first copper layer 4. It should be noted that this utility model has structural adaptability, that is, copper can be plated on both sides of the first substrate 1, or copper can be plated only on one side of the first substrate 1. This utility model is described in detail using copper plating on both sides of the first substrate 1 as an example.

[0022] The sum of the thicknesses of the first substrate 1 and the nanoporous substrate 2 is 2.5-8 μm, preferably 4.5 μm. The thickness of the underlayer 3 is 10-20 nm, preferably 10 nm. The thickness of the copper layer is 300-1000 nm, preferably 1000 nm. This reduces weight and increases battery energy density while ensuring conductivity.

[0023] The nanoporous substrate 2 is a porous structure with a pore size of 10-20 nm and a porosity of 25-45%. The nanopores on the nanoporous substrate 2 are bottleneck-shaped. By baking the nanopores at high temperature under constant transverse tension and simultaneously heat-treating them, a nanopore necking effect is formed. The heat treatment causes the nanopores to shrink, forming a bottleneck structure. The moderate shrinkage of the nanopores forms anchoring points to enhance the adhesion of the copper layer. This not only maintains the adhesion provided by the copper layer anchoring but also reduces the residue and penetration of sulfuric acid, significantly reducing the risk of corrosion.

[0024] The first substrate 1 is made of non-polar or low surface energy polymer materials, such as PP, PE, PS, PTFE, PMMA, PET, PA, PI, etc. No special restrictions are imposed here; the main purpose is to provide mechanical support for the base film. The nanoporous substrate 2 serves as a transition layer, mitigating the difference in thermal expansion coefficients between the polymeric first substrate 1 and the copper layer, reducing interfacial stress. After simultaneous biaxial stretching, it is immersed in petroleum ether or supercritical CO2 extraction of paraffin to form a porous structure with a pore size of 30-50 nm. Double-sided magnetron sputtering is then applied. The machine deposits a base layer 3 on both sides A and B. The pre-deposited roll film is then fed to the thin film stretching line for necking modification. After modification, the pore size of the nanopores is 10-20nm and the porosity is 25-45%. The double-sided magnetron sputtering machine performs a second magnetron sputtering to deposit a first copper layer with a thickness of 80nm on each side. The magnetron sputtered roll film is then fed to the gripper-type horizontal double-sided water plating line. Sides A and B are water-plated, and a second copper layer 5 is quickly water-plated on the first copper layer 4 to form a copper layer with a total thickness of 1000nm on one side, thus obtaining a composite copper foil.

[0025] Through experiments, the inventors discovered that the composite copper foil provided by this invention has a peel strength that is more than 300% higher than that of traditional copper foil. After being stored at 85°C for 168 hours, no copper layer falls off. It is suitable for high energy density batteries, and the capacity retention rate is >80% after 1000 cycles.

[0026] The technical scope of this utility model is not limited to the content described above. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this utility model, and all such modifications and variations should fall within the protection scope of this utility model.

Claims

1. A corrosion-resistant nanoporous composite copper foil, characterized in that: It includes a first substrate (1), on which at least one side is sequentially provided a nanoporous substrate (2), a base layer (3) and a copper layer. The nanoporous substrate (2) has a porous structure, and the nanopores on the nanoporous substrate (2) are bottleneck-shaped to form anchor points.

2. The corrosion-resistant nanoporous composite copper foil according to claim 1, characterized in that: The pore size of the nanopore is 10-20 nm.

3. The corrosion-resistant nanoporous composite copper foil according to claim 2, characterized in that: The porosity of the nanoporous substrate (2) is 25-45%.

4. The corrosion-resistant nanoporous composite copper foil according to claim 3, characterized in that: The sum of the thicknesses of the first substrate (1) and the nanoporous substrate (2) is 2.5-8 μm.

5. The corrosion-resistant nanoporous composite copper foil according to claim 4, characterized in that: The thickness of the base layer (3) is 10-20 nm.

6. The corrosion-resistant nanoporous composite copper foil according to claim 5, characterized in that: The thickness of the copper layer is 300-1000 nm.

7. The corrosion-resistant nanoporous composite copper foil according to claim 6, characterized in that: The copper layer includes a first copper layer (4) attached to the surface of the underlayment (3) and a second copper layer (5) attached to the surface of the first copper layer (4).

8. The corrosion-resistant nanoporous composite copper foil according to claim 7, characterized in that: The thickness of the first copper layer (4) is less than one-third of the thickness of the copper layer.

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