Three-dimensional composite copper foil for solid-state lithium battery

Abstract

The utility model discloses a three-dimensional composite copper foil for a solid-state lithium battery, which comprises a support layer, the support layer is a porous membrane layer or a fiber membrane layer, two sides of the support layer are respectively provided with a first metallization layer and a second metallization layer, one side of the first metallization layer far away from the support layer is provided with a third metallization layer, and the other side of the first metallization layer far away from the support layer is provided with a third metallization layer. A fourth metallization layer is arranged on the face, away from the supporting layer, of the second metallization layer, a first conductive copper layer is arranged on the face, away from the first metallization layer, of the third metallization layer, and a second conductive copper layer is arranged on the face, away from the second metallization layer, of the fourth metallization layer. The weight of the solid-state lithium battery can be reduced, the manufacturing cost of the solid-state lithium battery can be reduced, and meanwhile, the charging and discharging speed of the solid-state lithium battery can be increased.

Description

Technical Field

[0001] The utility model relates to the technical field of battery production, in particular to a three-dimensional composite copper foil for solid-state lithium batteries. Background Art

[0002] Existing solid-state lithium batteries generally use copper foil as the negative electrode current collector. Since copper foil is generally solid copper, it is heavy, and the copper material is large and expensive, which leads to the heavy weight of solid-state lithium batteries and increases the manufacturing cost of solid-state lithium batteries. At the same time, during the charge and discharge process of solid-state lithium batteries, because the copper foil does not have holes for lithium ions in the electrolyte to pass through, the speed at which lithium ions in the electrolyte move from one side of the copper foil to the other side is relatively slow, reducing the charge and discharge speed of the solid-state lithium battery. Utility Model Content

[0003] In order to overcome the shortcomings of the existing technology, the utility model provides a three-dimensional composite copper foil for solid-state lithium batteries, which can reduce the weight of solid-state lithium batteries and reduce the manufacturing cost of solid-state lithium batteries, while increasing the charging and discharging speed of solid-state lithium batteries.

[0004] The technical solution adopted by the utility model to solve its technical problems is:

[0005] The utility model provides a three-dimensional composite copper foil for solid-state lithium batteries, comprising a support layer, wherein the support layer is a porous membrane layer or a fiber membrane layer, and a first metallization layer and a second metallization layer are respectively provided on both sides of the support layer, a third metallization layer is provided on a side of the first metallization layer away from the support layer, a fourth metallization layer is provided on a side of the second metallization layer away from the support layer, a first conductive copper layer is provided on a side of the third metallization layer away from the first metallization layer, and a second conductive copper layer is provided on a side of the fourth metallization layer away from the second metallization layer.

[0006] As a preferred technical solution, the porous membrane layer is a PET porous membrane layer, a PP porous membrane layer, a PI porous membrane layer or a PE porous membrane layer.

[0007] As a preferred technical solution, the fiber membrane layer is a PET fiber membrane layer, a PP fiber membrane layer, a PI fiber membrane layer or a PE fiber membrane layer.

[0008] As a preferred technical solution, the pores of the porous membrane layer or fiber membrane layer have a pore size of 0.05-500 μm and a porosity of 0.1%-80%.

[0009] As a preferred technical solution, the materials of the first metallization layer and the second metallization layer are both one or more combinations of cobalt, aluminum, nickel, cadmium, magnesium, lithium and manganese.

[0010] As a preferred technical solution, the third metallization layer and the fourth metallization layer are both made of copper or copper alloy.

[0011] As a preferred technical solution, the thickness of the support layer is 1-30 μm.

[0012] As a preferred technical solution, the thickness of the first metallization layer and the second metallization layer are both 5-100 nm, and the thickness of the third metallization layer and the fourth metallization layer are both 10-200 nm.

[0013] As a preferred technical solution, the thickness of the first conductive copper layer and the second conductive copper layer are both 500-2000 nm.

[0014] The beneficial effects of the present invention are as follows: the present invention provides a support layer, which is a porous membrane layer or a fiber membrane layer, which can reduce the weight of the composite copper foil and the amount of copper material used, thereby reducing the weight of the solid-state lithium battery and the manufacturing cost of the solid-state lithium battery. In addition, during the charging and discharging process of the solid-state lithium battery, the holes on the porous membrane layer or the holes on the fiber membrane layer can serve as channels for the movement of lithium ions in the electrolyte, so that the lithium ions in the electrolyte of the solid-state lithium battery can quickly move from one side of the composite copper foil to the other side of the composite copper foil, thereby improving the charging and discharging speed of the solid-state lithium battery. By providing the first conductive copper layer and the second conductive copper layer, the current-carrying performance requirements and tensile strength requirements of the composite copper foil can be met, thereby meeting the performance requirements of the solid-state lithium battery. In addition, the first metallization layer is provided to isolate the first conductive copper layer and the support layer, and the second metallization layer is provided to isolate the second conductive copper layer and the support layer, thereby protecting the support layer. During the high and low temperature cycle test of the solid-state lithium battery, the support layer can be prevented from being burned through, thereby improving the stability of the composite copper foil during the high and low temperature cycle test of the solid-state lithium battery. The third and fourth metallization layers can improve the adhesion between the first metallization layer and the first conductive copper layer, and the adhesion between the second metallization layer and the second conductive copper layer, thereby preventing the first conductive copper layer and the second conductive copper layer from falling off. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0016] Figure 1 This is a schematic structural diagram of a three-dimensional composite copper foil for solid-state lithium batteries provided by one embodiment of the present invention;

[0017] Figure 2 is based on Figure 1 The three-dimensional composite copper foil for solid-state lithium batteries shown is a flow chart of a method for preparing the three-dimensional composite copper foil for solid-state lithium batteries. DETAILED DESCRIPTION

[0018] The following will clearly and completely describe the concept, specific structure and technical effects of the present invention in combination with the embodiments and drawings, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by technical personnel in this field without creative work are within the scope of protection of the present invention. In addition, all the connection / connection relationships involved in the patent do not refer to the direct connection of components, but refer to the fact that a better connection structure can be formed by adding or reducing connection accessories according to the specific implementation situation. The various technical features in the creation of the present invention can be combined interactively without conflicting with each other.

[0019] Please refer to Figure 1 One embodiment of the present invention provides a three-dimensional composite copper foil for a solid-state lithium battery, comprising a support layer 10, which is a porous membrane layer or a fiber membrane layer. A first metallization layer 20 and a second metallization layer 30 are provided on both sides of the support layer 10, respectively. A third metallization layer 40 is provided on the side of the first metallization layer 20 facing away from the support layer 10. A fourth metallization layer 50 is provided on the side of the second metallization layer 30 facing away from the support layer 10. A first conductive copper layer 60 is provided on the side of the third metallization layer 40 facing away from the first metallization layer 20. A second conductive copper layer 70 is provided on the side of the fourth metallization layer 50 facing away from the second metallization layer 30.

[0020] Through the above structure, the composite copper foil of the present invention, the support layer 10 is a porous membrane layer or a fiber membrane layer, which plays the role of supporting the entire composite copper foil, has the characteristics of light weight, low cost, and good ductility, can reduce the weight of the composite copper foil and can reduce the amount of copper material, thereby reducing the weight of the solid-state lithium battery and the manufacturing cost of the solid-state lithium battery, while improving the ductility of the composite copper foil, can avoid the solid-state lithium battery from being damaged or broken due to the expansion or contraction of the electrolyte during the charge and discharge process, and during the charge and discharge process of the solid-state lithium battery, the holes on the porous membrane layer or the holes on the fiber membrane layer can serve as channels for the movement of lithium ions in the electrolyte, so that the lithium ions in the electrolyte of the solid-state lithium battery can quickly move from one side of the composite copper foil to the other side of the composite copper foil, thereby improving the charge and discharge speed of the solid-state lithium battery. The first conductive copper layer 60 and the second conductive copper layer 70 are provided with good conductivity, can meet the current carrying performance requirements and tensile strength requirements of the composite copper foil, thereby meeting the performance requirements of the solid-state lithium battery. The first metallization layer 20 is provided to isolate the first conductive copper layer 60 from the support layer 10, and the second metallization layer 30 is provided to isolate the second conductive copper layer 70 from the support layer 10, thereby protecting the support layer 10. During the high and low temperature cycle test of the solid-state lithium battery, it can prevent the support layer 10 from being burned through, thereby improving the stability of the composite copper foil during the high and low temperature cycle test of the solid-state lithium battery. The third metallization layer 40 is provided to improve the adhesion between the first metallization layer 20 and the first conductive copper layer 60, thereby preventing the first conductive copper layer 60 from falling off. The fourth metallization layer 50 is provided to improve the adhesion between the second metallization layer 30 and the second conductive copper layer 70, thereby preventing the second conductive copper layer 70 from falling off.

[0021] In this embodiment, a first metallization layer 20 and a second metallization layer 30 are respectively provided on both sides of the support layer 10 by magnetron sputtering, evaporation or chemical plating. A third metallization layer 40 is provided on a side of the first metallization layer 20 away from the support layer 10 by magnetron sputtering, evaporation or chemical plating. A fourth metallization layer 50 is provided on a side of the second metallization layer 30 away from the support layer 10 by magnetron sputtering, evaporation or chemical plating. A first conductive copper layer 60 is provided on a side of the third metallization layer 40 away from the first metallization layer 20 by electroplating or evaporation. A second conductive copper layer 70 is provided on a side of the fourth metallization layer 50 away from the second metallization layer 30 by electroplating or evaporation.

[0022] The porous membrane layer can be a PET (Polyethylene terephthalate) porous membrane layer, a PP (Polypropylene) porous membrane layer, a PI (Polyimide) porous membrane layer, or a PE (Polyethylene) porous membrane layer. The low density of the PET, PP, PI, and PE porous membrane layers further reduces the weight of the composite copper foil, thereby further reducing the weight of the solid-state lithium battery and facilitating manufacturing.

[0023] The fiber membrane layer is a PET fiber membrane layer, a PP fiber membrane layer, a PI fiber membrane layer, or a PE fiber membrane layer. The PET fiber membrane layer, the PP fiber membrane layer, the PI fiber membrane layer, and the PE fiber membrane layer have low density, which can further reduce the weight of the composite copper foil, thereby further reducing the weight of the solid-state lithium battery and facilitating manufacturing.

[0024] The pores of the porous membrane layer or fiber membrane layer have a pore size of 0.05-500 μm and a porosity of 0.1%-80%. This value ensures that lithium ions can pass through the pores, and when the first metallization layer 20 and the second metallization layer 30 are respectively provided on both sides of the support layer 10 by magnetron sputtering, evaporation or chemical plating, metal filling in the pores can be avoided.

[0025] The materials of the first metallization layer 20 and the second metallization layer 30 are both one or more combinations of cobalt, aluminum, nickel, cadmium, magnesium, lithium and manganese. Using multiple combinations of metals can form a dense isolation layer.

[0026] The third metallization layer 40 and the fourth metallization layer 50 are both made of copper or a copper alloy, and the first conductive copper layer 60 and the second conductive copper layer 70 are both made of copper. By using copper or a copper alloy for the third metallization layer 40 and the fourth metallization layer 50, when the first conductive copper layer 60 is formed on a surface of the third metallization layer 40 away from the first metallization layer 20 by electroplating or vapor deposition, and when the second conductive copper layer 70 is formed on a surface of the fourth metallization layer 50 away from the second metallization layer 30 by electroplating or vapor deposition, the speed of forming the first conductive copper layer 60 and the second conductive copper layer 70 can be increased.

[0027] The thickness of the supporting layer 10 is 1-30 μm (micrometer), preferably 10 μm, the thickness of the first metallization layer 20 and the second metallization layer 30 are both 5-100 nm (nanometer), preferably 50 nm, the thickness of the third metallization layer 40 and the fourth metallization layer 50 are both 10-200 nm, preferably 100 nm, the thickness of the first conductive copper layer 60 and the second conductive copper layer 70 are both 500-2000 nm, preferably 1000 nm. With this thickness, the total thickness of the composite copper foil of the present invention is between 2.03-34.6 μm. The small thickness can further reduce the weight of the composite copper foil, thereby further reducing the weight of the solid-state lithium battery.

[0028] Please refer to Figure 2 The present invention further provides a method for preparing the solid-state lithium battery composite copper foil based on the solid-state lithium battery composite copper foil, comprising the following steps:

[0029] S1. Provide a support layer 10. The width and length of the support layer 10 can be adjusted according to actual conditions. The thickness of the support layer 10 is 1-30 μm. The support layer 10 is a porous membrane layer or a fiber membrane layer. The porous membrane layer can be a PET porous membrane layer, a PP porous membrane layer, a PI porous membrane layer, or a PE porous membrane layer. The fiber membrane layer can be a PET fiber membrane layer, a PP fiber membrane layer, a PI fiber membrane layer, or a PE fiber membrane layer. The pores in the porous membrane layer or fiber membrane layer have a pore diameter of 0.05-500 μm and a porosity of 0.1%-80%.

[0030] S2. Deposit a first metallization layer 20 and a second metallization layer 30 on both sides of the support layer 10 by magnetron sputtering, evaporation, or chemical plating. Both the first metallization layer 20 and the second metallization layer 30 are made of one or more of cobalt, aluminum, nickel, cadmium, magnesium, lithium, and manganese. Each of the first metallization layer 20 and the second metallization layer 30 has a thickness of 5-100 nm.

[0031] S3. A third metallization layer 40 is formed on a surface of the first metallization layer 20 remote from the support layer 10, and a fourth metallization layer 50 is formed on a surface of the second metallization layer 30 remote from the support layer 10 by magnetron sputtering, evaporation, or chemical plating. Both the third metallization layer 40 and the fourth metallization layer 50 are made of copper or a copper alloy. Each of the third metallization layer 40 and the fourth metallization layer 50 has a thickness of 10-200 nm.

[0032] S4. A first conductive copper layer 60 is formed on a surface of the third metallization layer 40 away from the first metallization layer 20, and a second conductive copper layer 70 is formed on a surface of the fourth metallization layer 50 away from the second metallization layer 30 by electroplating or evaporation. The first conductive copper layer 60 and the second conductive copper layer 70 are both made of copper, and each has a thickness of 500-2000 nm.

[0033] The preparation method of the utility model has a simple process and is easy to manufacture. The composite copper foil prepared is light in weight and low in cost, thereby reducing the weight of the solid-state lithium battery and reducing the manufacturing cost of the solid-state lithium battery. At the same time, it can increase the charge and discharge speed of the solid-state lithium battery, greatly meeting the use requirements.

[0034] The above is a specific description of the preferred implementation of the present invention, but the invention of the present invention is not limited to the embodiments. Those skilled in the art can make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A three-dimensional composite copper foil for solid-state lithium batteries, characterized in that: The invention comprises a supporting layer, wherein the supporting layer is a porous membrane layer or a fiber membrane layer, and a first metallization layer and a second metallization layer are respectively provided on both sides of the supporting layer, a third metallization layer is provided on a side of the first metallization layer away from the supporting layer, a fourth metallization layer is provided on a side of the second metallization layer away from the supporting layer, a first conductive copper layer is provided on a side of the third metallization layer away from the first metallization layer, and a second conductive copper layer is provided on a side of the fourth metallization layer away from the second metallization layer.

2. The three-dimensional composite copper foil for solid-state lithium batteries according to claim 1, characterized in that: The porous membrane layer is a PET porous membrane layer, a PP porous membrane layer, a PI porous membrane layer or a PE porous membrane layer.

3. The three-dimensional composite copper foil for solid-state lithium batteries according to claim 1, characterized in that: The fiber membrane layer is a PET fiber membrane layer, a PP fiber membrane layer, a PI fiber membrane layer or a PE fiber membrane layer.

4. The three-dimensional composite copper foil for solid-state lithium batteries according to claim 1, characterized in that: The pores of the porous membrane layer or fiber membrane layer have a pore diameter of 0.05-500 μm and a porosity of 0.1%-80%.

5. The three-dimensional composite copper foil for solid-state lithium batteries according to claim 1, characterized in that: The material of the first metallization layer and the second metallization layer is one of cobalt, aluminum, nickel, cadmium, magnesium, lithium and manganese.

6. The three-dimensional composite copper foil for solid-state lithium batteries according to claim 1, characterized in that: The third metallization layer and the fourth metallization layer are both made of copper or copper alloy.

7. The three-dimensional composite copper foil for solid-state lithium batteries according to claim 1, characterized in that: The thickness of the support layer is 1-30 μm.

8. The three-dimensional composite copper foil for solid-state lithium batteries according to claim 1, characterized in that: The thickness of the first metallization layer and the second metallization layer are both 5-100 nm, and the thickness of the third metallization layer and the fourth metallization layer are both 10-200 nm.

9. The three-dimensional composite copper foil for solid-state lithium batteries according to claim 1, characterized in that: The thickness of the first conductive copper layer and the second conductive copper layer are both 500-2000 nm.

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