Three-dimensional composite copper foil for solid lithium batteries and method for manufacturing the same

Abstract

This invention provides a three-dimensional composite copper foil for solid lithium batteries and a method for manufacturing the same, which can reduce the weight of solid lithium batteries, lower the manufacturing cost of solid lithium batteries, and improve the charge and discharge speed of solid lithium batteries. [Solution] The three-dimensional composite copper foil for solid lithium batteries includes a support layer 10, the support layer being a porous film layer or a fiber film layer, a first metallized layer 20 and a second metallized layer 30 are provided on both sides of the support layer, a third metallized layer 40 is provided on the side of the first metallized layer away from the support layer, a fourth metallized layer 50 is provided on the side of the second metallized layer away from the support layer, a first conductive copper layer 60 is provided on the side of the third metallized layer away from the first metallized layer, and a second conductive copper layer 70 is provided on the side of the fourth metallized layer away from the second metallized layer.

Description

Technical Field

[0001] The present invention relates to the technical field of battery manufacturing, and specifically to a three-dimensional composite copper foil for solid lithium batteries and a manufacturing method thereof.

Background Art

[0002] In conventional solid lithium batteries, copper foil is generally used as the negative electrode current collector. Since copper foil is generally solid copper, it is heavy, the amount of copper material used is large, and the cost is high. Therefore, the weight of the solid lithium battery increases, and the manufacturing cost of the solid lithium battery rises. At the same time, in the charging and discharging process of the solid lithium battery, since there are no pores in the copper foil through which lithium ions in the electrolyte can pass, the speed at which lithium ions in the electrolyte move from one side of the copper foil to the opposite side of the copper foil becomes slow, and the charging and discharging speed of the solid lithium battery decreases.

Summary of the Invention

Problems to be Solved by the Invention

[0003] In order to overcome the drawbacks of the prior art, the present invention provides a three-dimensional composite copper foil for solid lithium batteries and a manufacturing method thereof, which can reduce the weight of the solid lithium battery, reduce the manufacturing cost of the solid lithium battery, and improve the charging and discharging speed of the solid lithium battery.

[0004] The technical solutions adopted by the present invention to solve its technical problems are as follows.

[0005] In a first aspect of the present invention, a three-dimensional composite copper foil for a solid lithium battery is provided. The three-dimensional composite copper foil for a solid lithium battery includes a support layer, the support layer being a porous film layer or a fiber film layer, a first metallized layer and a second metallized layer are provided on both sides of the support layer, a third metallized layer is provided on the side of the first metallized layer away from the support layer, a fourth metallized layer is provided on the side of the second metallized layer away from the support layer, a first conductive copper layer is provided on the side of the third metallized layer away from the first metallized layer, and a second conductive copper layer is provided on the side of the fourth metallized layer away from the second metallized layer.

[0006] A preferred technical solution is 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.

[0007] A preferred technical solution is that the fiber film layer is a PET fiber film layer, a PP fiber film layer, a PI fiber film layer, or a PE fiber film layer.

[0008] A preferred technical solution is that the pores in the porous membrane layer or fiber membrane layer have a pore diameter of 0.05 to 500 μm and a porosity of 0.1% to 80%.

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

[0010] As a preferred technical solution, the material of both the third and fourth metallized layers is copper or a copper alloy.

[0011] A preferred technical solution is that the thickness of the support layer is 1 to 13 μm.

[0012] As a preferred technical solution, the first and second metallized layers each have a thickness of 5 to 100 nm, and the third and fourth metallized layers each have a thickness of 10 to 200 nm.

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

[0014] In a second aspect of the present invention, Step S1 provides a support layer which is a porous membrane layer or a fiber membrane layer, Step S2 involves providing a first metallized layer and a second metallized layer on both sides of the support layer, respectively, by magnetron sputtering, vapor deposition, or chemical plating. Step S3: A third metallized layer is provided on the surface of the first metallized layer away from the support layer, and a fourth metallized layer is provided on the surface of the second metallized layer away from the support layer, by magnetron sputtering, vapor deposition, or chemical plating. A method for manufacturing a three-dimensional composite copper foil for a solid lithium battery is provided, which includes step S4 of providing a first conductive copper layer on a surface of the third metallized layer away from the first metallized layer by electroplating or vapor deposition, and providing a second conductive copper layer on a surface of the fourth metallized layer away from the second metallized layer.

[0015] The beneficial effects of the present invention are as follows: The present invention reduces the weight of the composite copper foil and the amount of copper material used by the support layer, which is a porous film layer or fiber film layer, thereby reducing the weight of the solid lithium battery and its manufacturing cost. Furthermore, during the charging and discharging process of the solid lithium battery, the pores on the porous film layer or fiber film layer become the movement path for lithium ions in the electrolyte, so that lithium ions in the electrolyte of the solid lithium battery can move quickly from one side of the composite copper foil to the other side, thereby improving the charging and discharging speed of the solid lithium battery. In addition, the provided first conductive copper layer and second conductive copper layer satisfy the requirements for current conductivity and tensile strength of the composite copper foil, thereby satisfying the performance requirements of the solid lithium battery. Furthermore, the provided first metallized layer separates the first conductive copper layer from the support layer, and the provided second metallized layer separates the second conductive copper layer from the support layer, thereby protecting the support layer. This prevents burnout of the support layer during high-temperature and low-temperature cycle testing of solid lithium batteries, thereby improving the stability of the composite copper foil during high-temperature and low-temperature cycle testing of solid lithium batteries. The provided third and fourth metallized layers improve the adhesion between the first metallized layer and the first conductive copper layer, as well as the adhesion between the second metallized layer and the second conductive copper layer, thereby preventing the first and second conductive copper layers from falling off. [Brief explanation of the drawing]

[0016] The present invention will be further described below in conjunction with the attached drawings and embodiments.

[0017] [Figure 1] Figure 1 is a schematic diagram of a three-dimensional composite copper foil for a solid lithium battery provided by an embodiment of the present invention. [Figure 2] Figure 2 is a flowchart illustrating a schematic method for manufacturing a three-dimensional composite copper foil for solid lithium batteries, based on the three-dimensional composite copper foil for solid lithium batteries shown in Figure 1. [Modes for carrying out the invention]

[0018] To ensure a thorough understanding of the object, features, and effects of the present invention, the concept, specific configuration, and technical effects of the present invention are described below clearly and completely, in conjunction with the examples and drawings. Clearly, the examples described are not all of the examples of the present invention, but only a selection. All other examples that can be obtained by those skilled in the art without creative effort based on the examples of the present invention are included within the scope of the protection of the present invention. Furthermore, all connection / connection relationships relating to this patent refer not merely to the direct connection of parts, but to the fact that a better connection structure can be formed by adding or removing connecting accessories depending on the specific implementation. The various technical features of the present invention can be combined with one another without contradiction.

[0019] Referring to Figure 1, a three-dimensional composite copper foil for a solid lithium battery provided by one embodiment of the present invention includes a support layer 10 which is a porous film layer or a fiber film layer. A first metallized layer 20 and a second metallized layer 30 are provided on both sides of the support layer 10, respectively. A third metallized layer is provided on the side of the first metallized layer 20 away from the support layer 10. A fourth metallized layer 50 is provided on the side of the second metallized layer 30 away from the support layer 10. A first conductive copper layer 60 is provided on the side of the third metallized layer 40 away from the first metallized layer 20. A second conductive copper layer 70 is provided on the side of the fourth metallized layer 50 away from the second metallized layer 30.

[0020] Due to the above structure, the composite copper foil of the present invention has a support layer 10 which is a porous film layer or a fiber film layer, which plays a role in supporting the entire composite copper foil, and has features such as being lightweight, low cost, and good ductility, which reduces the weight of the composite copper foil and the amount of copper material used, thereby reducing the weight of the solid lithium battery and its manufacturing cost. At the same time, the ductility of the composite copper foil can be improved, and damage or breakage due to expansion or contraction of the electrolyte during the charging and discharging process of the solid lithium battery can be avoided. In addition, during the charging and discharging process of the solid lithium battery, the pores on the porous film layer or fiber film layer become a movement path for lithium ions in the electrolyte, so lithium ions in the electrolyte of the solid lithium battery can move quickly from one side of the composite copper foil to the other side, thereby improving the charging and discharging speed of the solid lithium battery. The provided first conductive copper layer 60 and second conductive copper layer 70 have good conductivity and can meet the current-carrying performance requirements and tensile strength requirements of the composite copper foil, and can meet the performance requirements of the solid lithium battery. The provided first metallized layer 20 serves to separate the first conductive copper layer 60 from the support layer 10, and the provided second metallized layer 30 serves to separate the second conductive copper layer 70 from the support layer 10, thereby protecting the support layer 10. This prevents the support layer 10 from burning out during high-temperature and low-temperature cycle tests of the solid lithium battery, improving the stability of the composite copper foil during high-temperature and low-temperature cycle tests of the solid lithium battery. The provided third metallized layer 40 improves the adhesion between the first metallized layer 20 and the first conductive copper layer 60, preventing the first conductive copper layer from falling off. The provided fourth metallized layer 50 improves the adhesion between the second metallized layer 30 and the second conductive copper layer 70, preventing the second conductive copper layer 70 from falling off.

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

[0022] The porous membrane layer is 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. Since the PET porous membrane layer, the PP porous membrane layer, the PI porous membrane layer, and the PE porous membrane layer have low densities, the weight of the composite copper foil can be further reduced, the weight of the solid lithium battery can be further reduced, and the manufacturing can be facilitated.

[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. Since the PET fiber membrane layer, the PP fiber membrane layer, the PI fiber membrane layer, and the PE fiber membrane layer have low densities, the weight of the composite copper foil can be further reduced, the weight of the solid lithium battery can be further reduced, and the manufacturing can be facilitated. [[ID=​​

[0025] The materials of the first metallization layer 20 and the second metallization layer 30 are both one or a combination of more than one of cobalt, aluminum, nickel, cadmium, magnesium, lithium, and manganese. By using various combinations of metals, a dense insulating layer can be formed.

[0026] The materials of the third metallization layer 40 and the fourth metallization layer 50 are both copper or a copper alloy, and the materials of the first conductive copper layer 60 and the second conductive copper layer 70 are both copper. By adopting copper or a copper alloy for the third metallization layer 40 and the fourth metallization layer 50, when a first conductive copper layer is provided on the surface of the third metallization layer 40 away from the first metallization layer 20 and a second conductive copper layer 70 is provided on the surface of the fourth metallization layer 50 away from the second metallization layer 30 by means of electroplating or vapor deposition, the formation rates of the first conductive copper layer 60 and the second conductive copper layer 70 can be improved.

[0027] The thickness of the support layer 10 is 1 to 30 μm (micrometers), preferably 10 μm. The first metallization layer 20 and the second metallization layer 30 both have a thickness of 5 to 100 nm (nanometers), preferably 50 nm. The third metallization layer 40 and the fourth metallization layer 50 both have a thickness of 10 to 200 nm, preferably 100 nm. The first conductive copper layer 60 and the second conductive copper layer 70 both have a thickness of 500 to 2000 nm, preferably 1000 nm. With such thicknesses, the total thickness of the composite copper foil of the present invention is 2.03 to 34.6 μm. Due to the thin thickness, the weight of the composite copper foil is further reduced, and the weight of the solid lithium battery is further reduced.

[0028] Referring to FIG. 2, the present invention further provides a method for manufacturing a composite copper foil for a solid lithium battery, which includes the following steps based on the above composite copper foil for a solid lithium battery.

[0029] S1, a support layer 10 is provided. The width and length of the support layer 10 can be set according to the actual situation. The thickness of the support layer 10 is 1 to 30 μm. The support layer 10 is a porous membrane layer or a fiber membrane layer. 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. 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 pores of the porous membrane layer or fiber membrane layer have a pore diameter of 0.05 to 500 μm and a porosity of 0.1% to 80%.

[0030] S2, a first metallized layer 20 and a second metallized layer 30 are provided on both sides of the support layer 10 by magnetron sputtering, vapor deposition, or chemical plating. The materials of both the first metallized layer 20 and the second metallized layer 30 are one or more of the following: cobalt, aluminum, nickel, cadmium, magnesium, lithium, and manganese. Both the first metallized layer 20 and the second metallized layer 30 have a thickness of 5 to 100 nm.

[0031] S3. A third metallized layer 40 is provided on the surface of the first metallized layer 20 away from the support layer 10 by magnetron sputtering, vapor deposition, or chemical plating, and a fourth metallized layer 50 is provided on the surface of the second metallized layer 30 away from the support layer 10. The material of both the third metallized layer 40 and the fourth metallized layer 50 is copper or a copper alloy. Both the third metallized layer 40 and the fourth metallized layer 50 have a thickness of 10 to 200 nm.

[0032] S4. By electroplating or vapor deposition, a first conductive copper layer 60 is provided on the surface of the third metallized layer 40 away from the first metallized layer 20, and a second conductive copper layer 70 is provided on the surface of the fourth metallized layer 50 away from the second metallized layer 30. The material of both the first conductive copper layer 60 and the second conductive copper layer 70 is copper, and both the first conductive copper layer 60 and the second conductive copper layer 70 have a thickness of 500 to 2000 nm.

[0033] The manufacturing method of the present invention is simple and easy to manufacture. The manufactured composite copper foil is lightweight and low cost, thus reducing the weight of the solid lithium battery, lowering the manufacturing cost of the solid lithium battery, and at the same time improving the charge and discharge speed of the solid lithium battery, thereby greatly meeting the requirements for use.

[0034] The above is a specific description of preferred embodiments of the present invention, but the present invention is not limited to the above embodiments. Those skilled in the art can make various equivalent modifications and substitutions without departing from the spirit of the invention. All of these equivalent modifications or substitutions fall within the scope defined by the claims of this application.

Claims

1. A three-dimensional composite copper foil for solid lithium batteries, comprising a support layer, wherein the support layer is a porous film layer or a fiber film layer, a first metallized layer and a second metallized layer are provided on both sides of the support layer, a third metallized layer is provided on the side of the first metallized layer away from the support layer, a fourth metallized layer is provided on the side of the second metallized layer away from the support layer, a first conductive copper layer is provided on the side of the third metallized layer away from the first metallized layer, and a second conductive copper layer is provided on the side of the fourth metallized layer away from the second metallized layer.

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

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

5. The three-dimensional composite copper foil for a solid lithium battery according to claim 1, characterized in that the materials of both the first metallized layer and the second metallized layer are a combination of one or more of the following: cobalt, aluminum, nickel, cadmium, magnesium, lithium, and manganese.

6. The three-dimensional composite copper foil for a solid lithium battery according to claim 1, characterized in that the material of both the third metallized layer and the fourth metallized layer is copper or a copper alloy.

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

8. The three-dimensional composite copper foil for a solid lithium battery according to claim 1, characterized in that the thickness of the first metallized layer and the second metallized layer is both 5 to 100 nm, and the thickness of the third metallized layer and the fourth metallized layer is both 10 to 200 nm.

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

10. A method for manufacturing a three-dimensional composite copper foil for solid lithium batteries, Step S1 provides a support layer which is a porous membrane layer or a fibrous membrane layer, Step S2 involves providing a first metallized layer and a second metallized layer on both sides of the support layer, respectively, by magnetron sputtering, vapor deposition, or chemical plating. Step S3: A third metallized layer is provided on the surface of the first metallized layer away from the support layer, and a fourth metallized layer is provided on the surface of the second metallized layer away from the support layer, by magnetron sputtering, vapor deposition, or chemical plating. A method for manufacturing a three-dimensional composite copper foil for a solid lithium battery, characterized by including step S4 of providing a first conductive copper layer on a surface of the third metallized layer away from the first metallized layer by electroplating or vapor deposition, and providing a second conductive copper layer on a surface of the fourth metallized layer away from the second metallized layer.

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