Multi-metal protection composite copper foil for solid-state lithium battery

Abstract

The utility model discloses a multi-metal protection composite copper foil for a solid-state lithium battery. The multi-metal protection composite copper foil comprises a base film layer, a first conductive structure arranged on the front surface of the base film layer and a second conductive structure arranged on the back surface of the base film layer, the base membrane layer is a porous membrane layer or a fiber membrane layer; the first conductive structure comprises a first isolation layer, a first bonding layer, a first conductive copper layer and a first protection layer; the second conductive structure comprises a second isolation layer, a second combination layer, a second conductive copper layer and a second protection layer. The weight of the solid-state lithium battery can be reduced, the manufacturing cost of the solid-state lithium battery can be reduced, the service life of the solid-state lithium battery can be prolonged, and the charging and discharging speed of the solid-state lithium battery can be improved.

Description

Technical Field

[0001] This utility model relates to the field of battery manufacturing technology, specifically to a multi-metal protective composite copper foil for solid-state lithium batteries. Background Technology

[0002] Current solid-state lithium batteries typically use copper foil as the negative electrode current collector. Since copper foil is generally solid copper, it is heavy, and the large amount of copper used results in high cost, leading to a heavier solid-state lithium battery and increased manufacturing costs. Furthermore, copper foil is easily corroded by the electrolyte in solid-state lithium batteries, resulting in a shorter lifespan and reducing the overall battery lifespan. Additionally, during charging and discharging, the lack of pores on the copper foil for lithium ions in the electrolyte to pass through slows down the movement of lithium ions from one side of the copper foil to the other, reducing the charging and discharging speed of the solid-state lithium battery. Utility Model Content

[0003] In order to overcome the shortcomings of the prior art, this utility model provides a multi-metal protective composite copper foil for solid-state lithium batteries, which can reduce the weight and manufacturing cost of solid-state lithium batteries, while extending the service life and increasing the charging and discharging speed of solid-state lithium batteries.

[0004] The technical solution adopted by this utility model to solve its technical problem is:

[0005] This utility model provides a multi-metal protective composite copper foil for solid-state lithium batteries, comprising a base film layer, a first conductive structure disposed on the front side of the base film layer, and a second conductive structure disposed on the back side of the base film layer; the base film layer is a porous film layer or a fiber film layer; the first conductive structure includes a first insulating layer, a first bonding layer, a first conductive copper layer, and a first protective layer, wherein the first insulating layer is disposed on the front side of the base film layer, the first bonding layer is disposed on the side of the first insulating layer away from the base film layer, the first conductive copper layer is disposed on the side of the first bonding layer away from the first insulating layer, and the first protective layer is disposed on the side of the first conductive copper layer away from the first bonding layer; the second conductive structure includes a second insulating layer, a second bonding layer, a second conductive copper layer, and a second protective layer, wherein the second insulating layer is disposed on the back side of the base film layer, the second bonding layer is disposed on the side of the second insulating layer away from the base film layer, the second conductive copper layer is disposed on the side of the second bonding layer away from the second insulating layer, and the second protective layer is disposed on the side of the second conductive copper layer away from the second bonding 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 pore size of the porous membrane layer or fiber membrane layer is 0.05-500μm, and the porosity is 0.1%-80%.

[0009] As a preferred technical solution, the materials of the first isolation layer, the second isolation layer, the first protective layer, and the second protective layer are all one of cobalt, aluminum, nickel, cadmium, magnesium, lithium, and manganese.

[0010] As a preferred technical solution, both the first bonding layer and the second bonding layer are made of copper or copper alloy.

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

[0012] As a preferred technical solution, the thickness of the first isolation layer and the second isolation layer is 5-100nm, the thickness of the first bonding layer and the second bonding layer is 10-200nm, and the thickness of the first protective layer and the second protective layer is 5-2000nm.

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

[0014] The beneficial effects of this invention are as follows: The base film layer reduces the weight of the composite copper foil and the amount of copper material used, thereby reducing the weight and manufacturing cost of the solid-state lithium battery. The first and second conductive copper layers meet the current-carrying capacity and tensile strength requirements of the composite copper foil, thus satisfying the performance requirements of the solid-state lithium battery. The first and second protective layers protect the first and second conductive copper layers respectively, preventing electrolyte corrosion and extending the lifespan of the composite copper foil and consequently, the solid-state lithium battery. The base film layer is a porous or fiber film. During the charging and discharging process of the solid-state lithium battery, the pores in the porous or fiber film serve as channels for lithium ion movement in the electrolyte, allowing lithium ions to move rapidly from one side of the composite copper foil to the other, thereby increasing the charging and discharging speed of the solid-state lithium battery. In addition, by setting the first isolation layer and the second isolation layer, the first conductive copper layer and the base film layer can be isolated, and the second conductive copper layer and the base film layer can be isolated, thereby protecting the base film layer. During the high and low temperature cycle test of the solid-state lithium battery, the base film layer can be prevented from being burned through, thus improving the stability of the composite copper foil during the high and low temperature cycle test of the solid-state lithium battery. By setting the first bonding layer and the second bonding layer, the adhesion between the first isolation layer and the first conductive copper layer and the adhesion between the second isolation layer and the second conductive copper layer can be improved, thus preventing the first conductive copper layer and the second conductive copper layer from falling off. Attached Figure Description

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

[0016] Figure 1 This is a schematic diagram of the structure of a multi-metal protective composite copper foil for solid-state lithium batteries according to an embodiment of the present invention;

[0017] Figure 2 Based on Figure 1 The diagram shown is a flowchart illustrating a method for preparing a multi-metal protective composite copper foil for solid-state lithium batteries.

[0018] Figure 3 yes Figure 2 The flowchart shown is a schematic diagram of step S2 in the preparation method of multi-metal protective composite copper foil for solid-state lithium batteries.

[0019] Figure 4 yes Figure 2 The flowchart shown is a schematic diagram of step S3 in the preparation method of multi-metal protective composite copper foil for solid-state lithium batteries. Detailed Implementation

[0020] The following will clearly and completely describe the concept, specific structure, and technical effects of this utility model in conjunction with embodiments and accompanying drawings, so as to fully understand the purpose, features, and effects of this utility model. Obviously, the described embodiments are only a part of the embodiments of this utility model, not all of them. Other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are all within the scope of protection of this utility model. Furthermore, all connections / linkages involved in the patent do not simply refer to direct contact between components, but rather to the ability to form a better connection structure by adding or reducing connecting accessories according to specific implementation conditions. The various technical features in this utility model can be combined interactively without contradicting each other.

[0021] Please refer to Figure 1 An embodiment of this utility model provides a multi-metal protective composite copper foil for solid-state lithium batteries, including a base film layer 10, a first conductive structure 20 disposed on the front side of the base film layer 10, and a second conductive structure 30 disposed on the back side of the base film layer 10.

[0022] The base membrane layer 10 is a porous membrane layer or a fibrous membrane layer.

[0023] The first conductive structure 20 includes a first insulating layer 21, a first bonding layer 22, a first conductive copper layer 23, and a first protective layer 24. The first insulating layer 21 is disposed on the front side of the base film layer 10. The first bonding layer 22 is disposed on the side of the first insulating layer 21 away from the base film layer 10. The first conductive copper layer 23 is disposed on the side of the first bonding layer 22 away from the first insulating layer 21. The first protective layer 24 is disposed on the side of the first conductive copper layer 23 away from the first bonding layer 22.

[0024] The second conductive structure 30 includes a second insulating layer 31, a second bonding layer 32, a second conductive copper layer 33, and a second protective layer 34. The second insulating layer 31 is disposed on the back side of the base film layer 10. The second bonding layer 32 is disposed on the side of the second insulating layer 31 away from the base film layer 10. The second conductive copper layer 33 is disposed on the side of the second bonding layer 32 away from the second insulating layer 31. The second protective layer 34 is disposed on the side of the second conductive copper layer 33 away from the second bonding layer 32.

[0025] Through the above structure, the composite copper foil of this utility model, with the base film layer 10 serving as the support layer for the entire composite copper foil, features light weight, low cost, and good ductility. This reduces the weight of the composite copper foil and the amount of copper material used, thereby reducing the weight and manufacturing cost of the solid-state lithium battery. Simultaneously, it improves the ductility of the composite copper foil. The first conductive copper layer 23 and the second conductive copper layer 33 have good conductivity, meeting the current-carrying capacity and tensile strength requirements of the composite copper foil, thus satisfying the performance requirements of the solid-state lithium battery. The first isolation layer 21 and the second isolation layer 31 isolate the first conductive copper layer 23 from the base film layer 10 and the second conductive copper layer 33 from the base film layer 10, thereby protecting the base film layer 10. During high and low temperature cycling tests of the solid-state lithium battery, this protects the base film layer 10 from damage. The film layer 10 is heat-burned through, thus improving the stability of the composite copper foil during high and low temperature cycling tests of solid-state lithium batteries. The first bonding layer 22 improves the adhesion between the first insulating layer 21 and the first conductive copper layer 23, preventing the first conductive copper layer 23 from falling off. The second bonding layer 32 improves the adhesion between the second insulating layer 31 and the second conductive copper layer 33, preventing the second conductive copper layer 33 from falling off. The first protective layer 24 protects the first conductive copper layer 23, thus preventing the solid electrolyte in the solid-state lithium battery from corroding the first conductive copper layer 23. The second protective layer 34 protects the second conductive copper layer 33, thus preventing the solid electrolyte in the solid-state lithium battery from corroding the second conductive copper layer 33, extending the service life of the composite copper foil, thereby extending the service life of the solid-state lithium battery. In addition, the base film layer 10 is a porous film layer or a fiber film layer. During the charging and discharging process of the solid-state lithium battery, the pores on the porous film layer or the pores on the fiber film layer can serve as channels for the movement of lithium ions in the electrolyte, so that lithium ions in the electrolyte of the solid-state lithium battery can move quickly 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.

[0026] In this embodiment, a first isolation layer 21 and a second isolation layer 31 are respectively formed on the front and back sides of the base film layer 10 by magnetron sputtering, vapor deposition, or chemical plating. A first bonding layer 22 is formed on the side of the first isolation layer 21 away from the base film layer 10 by magnetron sputtering, vapor deposition, or chemical plating. A second bonding layer 32 is formed on the side of the second isolation layer 31 away from the base film layer 10 by magnetron sputtering, vapor deposition, or chemical plating. A first conductive copper layer 23 is formed on the side of the first bonding layer 22 away from the first isolation layer 21 by electroplating or vapor deposition. A second conductive copper layer 33 is formed on the side of the second bonding layer 32 away from the second isolation layer 31 by electroplating or vapor deposition. A first protective layer 24 is formed on the side of the first conductive copper layer 23 away from the first bonding layer 22 by magnetron sputtering or vapor deposition. A second protective layer 34 is formed on the side of the second conductive copper layer 33 away from the second bonding layer 32 by magnetron sputtering or vapor deposition.

[0027] The porous membrane layer can be made of PET (polyethylene terephthalate), PP (polypropylene), PI (polyimide), or PE (polyethylene). PET, PP, PI, and PE porous membrane layers have low densities, which further reduces the weight of the composite copper foil, thereby further reducing the weight of the solid-state lithium battery and facilitating manufacturing.

[0028] 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. PET, PP, PI, and PE fiber membrane layers have low density, which further reduces the weight of the composite copper foil, thereby further reducing the weight of the solid-state lithium battery, and also facilitating manufacturing.

[0029] The pore size of the porous membrane or fiber membrane is 0.05-500μm and the porosity is 0.1%-80%. This value can ensure that lithium ions can pass through the pores. When the first isolation layer 21 and the second isolation layer 31 are set on the front and back sides of the base film layer 10 by magnetron sputtering, vapor deposition or chemical plating, metal filling in the pores can be avoided.

[0030] The first isolation layer 21, the second isolation layer 31, the first protective layer 24, and the second protective layer 34 are all made of one or more combinations of cobalt, aluminum, nickel, cadmium, magnesium, lithium, and manganese. Using multiple combinations of metals can form a dense isolation layer. When the first protective layer 24 and the second protective layer 34 are made of lithium, they can also replenish the number of lithium ions in the electrolyte of the solid-state lithium battery, thereby improving the capacity and lifespan of the solid-state lithium battery.

[0031] The first bonding layer 22 and the second bonding layer 32 are both made of copper or copper alloy, and the first conductive copper layer 23 and the second conductive copper layer 33 are both made of copper. By using copper or copper alloy for the first bonding layer 22 and the second bonding layer 32, the formation speed of the first conductive copper layer 23 and the second conductive copper layer 33 can be increased when the first conductive copper layer 23 is set on the side of the first bonding layer 22 away from the first isolation layer 21 by electroplating or vapor deposition, and when the second conductive copper layer 33 is set on the side of the second bonding layer 32 away from the second isolation layer 31 by electroplating or vapor deposition.

[0032] The thickness of the base film layer 10 is 1-30 μm (micrometer), preferably 10 μm. The thickness of the first isolation layer 21 and the second isolation layer 31 is 5-100 nm (nanometer), preferably 50 nm. The thickness of the first bonding layer 22 and the second bonding layer 32 is 10-200 nm, preferably 100 nm. The thickness of the first conductive copper layer 23 and the second conductive copper layer 33 is 500-2000 nm, preferably 1000 nm. The thickness of the first protective layer 24 and the second protective layer 34 is 5-2000 nm, preferably 1000 nm. With this thickness, the total thickness of the composite copper foil of this invention is between 2.04-38.6 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.

[0033] Please refer to Figure 2 Based on the above-mentioned solid-state lithium battery composite copper foil, this utility model also provides a method for preparing solid-state lithium battery composite copper foil, including the following steps:

[0034] S1. Provide a base film layer 10. The width and length of the base film layer 10 can be set according to actual conditions. The thickness of the base film layer 10 is 1-30μm. The base film 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 pore size of the porous membrane layer or fiber membrane layer is 0.05-500μm, and the porosity is 0.1%-80%.

[0035] S2. A first conductive structure 20 is provided on the front side of the base film layer 10.

[0036] like Figure 3 As shown, step S2 includes the following steps:

[0037] S21. A first isolation layer 21 is formed on the front side of the base film layer 10 by magnetron sputtering, evaporation, or electroless deposition. The material of the first isolation layer 21 is one or more combinations of cobalt, aluminum, nickel, cadmium, magnesium, lithium, and manganese. The thickness of the first isolation layer 21 is 5-100 nm.

[0038] S22. A first bonding layer 22 is formed on the side of the first isolation layer 21 away from the base film layer 10 by magnetron sputtering, evaporation, or chemical plating. The first bonding layer 22 is made of copper or a copper alloy. The thickness of the first bonding layer 22 is 10-200 nm.

[0039] S23. A first conductive copper layer 23 is formed on the side of the first bonding layer 22 away from the first isolation layer 21 by electroplating or vapor deposition. The first conductive copper layer 23 is made of copper and has a thickness of 500-2000 nm.

[0040] S24. A first protective layer 24 is formed on the side of the first conductive copper layer 23 away from the first bonding layer 22 by magnetron sputtering or vapor deposition. The first protective layer 24 is made of one or more combinations of cobalt, aluminum, nickel, cadmium, magnesium, lithium, and manganese. The thickness of the first protective layer 24 is 5-2000 nm.

[0041] S3. A second conductive structure 30 is provided on the back side of the base film layer 10.

[0042] like Figure 4 As shown, step S3 includes the following steps:

[0043] S31. A second isolation layer 31 is formed on the back side of the base film layer 10 by magnetron sputtering, evaporation, or electroless deposition. The material of the second isolation layer 31 is one or more combinations of cobalt, aluminum, nickel, cadmium, magnesium, lithium, and manganese. The thickness of the second isolation layer 31 is 5-100 nm.

[0044] S32. A second bonding layer 32 is formed on the side of the second isolation layer 31 away from the base film layer 10 by magnetron sputtering, evaporation, or chemical plating. The material of the second bonding layer 32 is copper or a copper alloy. The thickness of the second bonding layer 32 is 10-200 nm.

[0045] S33. A second conductive copper layer 33 is formed on the side of the second bonding layer 32 away from the second isolation layer 31 by electroplating or vapor deposition. The material of the second conductive copper layer 33 is copper, and the thickness of the second conductive copper layer 33 is 500-2000 nm.

[0046] S34. A second protective layer 34 is formed on the side of the second conductive copper layer 33 away from the second bonding layer 32 by magnetron sputtering or vapor deposition. The material of the second protective layer 34 is one or more combinations of cobalt, aluminum, nickel, cadmium, magnesium, lithium and manganese. The thickness of the second protective layer 34 is 5-2000 nm.

[0047] The preparation method of this utility model is simple and easy to manufacture. The resulting composite copper foil is lightweight and low in cost, which can reduce the weight and manufacturing cost of solid-state lithium batteries. At the same time, it can extend the service life of solid-state lithium batteries and improve the charging and discharging speed of solid-state lithium batteries, which greatly meets the needs of users.

[0048] The above is a detailed description of the preferred embodiments of the present utility model. However, the present utility model is not limited to the described embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present utility model. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A multi-metal protective composite copper foil for solid-state lithium batteries, characterized in that, It includes a base film layer, a first conductive structure disposed on the front side of the base film layer, and a second conductive structure disposed on the back side of the base film layer; The base membrane layer is a porous membrane layer or a fibrous membrane layer; The first conductive structure includes a first isolation layer, a first bonding layer, a first conductive copper layer, and a first protective layer. The first isolation layer is disposed on the front side of the base film layer, the first bonding layer is disposed on the side of the first isolation layer away from the base film layer, the first conductive copper layer is disposed on the side of the first bonding layer away from the first isolation layer, and the first protective layer is disposed on the side of the first conductive copper layer away from the first bonding layer. The second conductive structure includes a second isolation layer, a second bonding layer, a second conductive copper layer, and a second protective layer. The second isolation layer is disposed on the back side of the base film layer, the second bonding layer is disposed on the side of the second isolation layer away from the base film layer, the second conductive copper layer is disposed on the side of the second bonding layer away from the second isolation layer, and the second protective layer is disposed on the side of the second conductive copper layer away from the second bonding layer.

2. The multi-metal protective 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 multi-metal protective composite copper foil for solid-state lithium batteries according to claim 1, characterized in that, The fiber membrane is a PET fiber membrane, a PP fiber membrane, a PI fiber membrane, or a PE fiber membrane.

4. The multi-metal protective composite copper foil for solid-state lithium batteries according to claim 1, characterized in that, The pore size of the porous membrane or fiber membrane is 0.05-500 μm, and the porosity is 0.1%-80%.

5. The multi-metal protective composite copper foil for solid-state lithium batteries according to claim 1, characterized in that, The first isolation layer, the second isolation layer, the first protective layer, and the second protective layer are all made of one of the following materials: cobalt, aluminum, nickel, cadmium, magnesium, lithium, and manganese.

6. The multi-metal protective composite copper foil for solid-state lithium batteries according to claim 1, characterized in that, The first bonding layer and the second bonding layer are both made of copper or copper alloy.

7. The multi-metal protective composite copper foil for solid-state lithium batteries according to claim 1, characterized in that, The thickness of the base film layer is 1-30 μm.

8. The multi-metal protective composite copper foil for solid-state lithium batteries according to claim 1, characterized in that, The thickness of the first isolation layer and the second isolation layer is 5-100nm, the thickness of the first bonding layer and the second bonding layer is 10-200nm, and the thickness of the first protective layer and the second protective layer is 5-2000nm.

9. The multi-metal protective composite copper foil for solid-state lithium batteries according to claim 1, characterized in that, The thickness of both the first and second conductive copper layers is 500-2000 nm.

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