Novel composite current collector and lithium ion battery

Abstract

The utility model relates to a novel composite current collector and a lithium ion battery, which comprise a polymer layer and metal conducting layers on two sides, a waterproof layer and a connecting layer are arranged between the polymer layer and the metal conducting layer on each side, and the waterproof layer and the connecting layer are sequentially arranged from inside to outside. According to the composite current collector, the waterproof layer is coated on the surface of the polymer layer to isolate external moisture from the polymer layer, so that the polymer layer is prevented from deteriorating due to absorption of moisture in the environment, and the moisture-proof performance of the composite current collector is improved; the waterproof layer comprises a silicone coating and a polyurethane coating, and the coating materials have good moisture resistance and durability and can effectively protect the polymer layer from being affected by moisture; the connection strength between the metal conductive layer and the waterproof layer in the composite current collector is improved through the connection layer, and a relatively strong chemical bond can be formed between the waterproof layer and the metal conductive layer, so that the connection strength between the laminated structures of the novel composite current collector is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of energy storage, and in particular to a novel composite current collector and a lithium ion battery. Background Art

[0002] The composite current collector is a special structure, which mainly adopts a three-part structure, consisting of an inner layer of polymer macromolecules and metal conductive layers on both sides. This structure can provide good insulation and conductivity, and is often used in electronic devices such as batteries and capacitors. In the manufacturing process of the composite current collector, the polymer macromolecule layer is usually prepared first, and then the metal conductive layer is deposited on the upper and lower surfaces of the macromolecule layer. There are many specific manufacturing processes, such as vacuum evaporation, magnetron sputtering, water electroplating, etc. The composite current collector has a wide range of applications, such as battery electrodes, integrated circuit pins, electromagnetic shielding materials, etc.

[0003] The polymer layer in the composite fluid collector is affected by environmental humidity, mainly because polymer materials are hygroscopic. When the environmental humidity is high, the polymer layer will absorb moisture in the environment, causing changes in its properties. The hygroscopicity of the polymer layer may lead to problems such as degradation of its insulation performance and unstable conductivity.

[0004] Therefore, developing a new composite current collector to solve the problem that the polymer layer of the existing composite current collector is easily deteriorated in a high humidity environment has become a technical problem that needs to be solved urgently. Utility Model Content

[0005] In order to solve the problem that the existing polymer polymer layer of composite fluid collector is susceptible to moisture and deterioration in a high humidity environment, the utility model provides a new composite fluid collector and lithium-ion battery, which can improve moisture resistance and can effectively protect the polymer polymer layer from moisture.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] A new type of composite fluid collector includes an inner layer of polymer polymer layer and a metal conductive layer on both sides. A waterproof layer and a connecting layer are provided between the polymer polymer layer and the metal conductive layer on each side, and the waterproof layer and the connecting layer are arranged sequentially from the inside to the outside.

[0008] By adopting the above technical scheme, a waterproof layer is coated on the surface of the polymer high molecular layer, which can isolate the polymer high molecular layer from external moisture and improve the moisture-proof performance; the material of the waterproof layer itself has good moisture-proof performance and durability, and can effectively protect the polymer high molecular layer from moisture; the connecting layer improves the connection strength between the metal conductive layer and the waterproof layer in the composite current collector, and can form a strong chemical bond between the waterproof layer and the metal conductive layer, ensuring that the composite current collector structure after the waterproof layer is added still has good connection strength.

[0009] As a preferred technical solution of the utility model, the waterproof layer includes a silicone coating and a polyurethane coating, and the silicone coating and the polyurethane coating are arranged in sequence from the inside to the outside.

[0010] By adopting the above technical solution, the waterproof layer is composed of a silicone coating and a polyurethane coating, has good moisture-proof performance and durability, and can effectively protect the polymer high molecular layer from the influence of moisture.

[0011] As a preferred technical solution of the utility model, a sealing layer is provided at the edge connection of the polymer macromolecular layer, the silicone coating and the polyurethane coating.

[0012] Preferably, the material of the sealing layer is silicone.

[0013] By adopting the above technical solution, the sealing layer is made of silicone material, which can protect the edge connections of the polymer polymer layer, silicone coating and polyurethane coating, and further enhance the moisture-proof performance of the composite fluid collection.

[0014] As a preferred technical solution of the present invention, the connecting layer is a conductive adhesive layer.

[0015] Furthermore, the thickness of the conductive adhesive layer is 2 nanometers to 50 nanometers.

[0016] As a preferred technical solution of the present utility model, the material of the polymer high molecular layer is polyethylene terephthalate.

[0017] Furthermore, the thickness of the polymer layer is 5 micrometers to 25 micrometers.

[0018] As a preferred technical solution of the present utility model, the material of the metal conductive layer is copper.

[0019] Furthermore, the thickness of the metal conductive layer is 5 nanometers to 100 nanometers.

[0020] As a preferred technical solution of the utility model, a protective layer is provided on the outer surface of the metal conductive layer.

[0021] Preferably, the protective layer is a ceramic coating, and the thickness of the ceramic coating is 5 nanometers to 50 nanometers.

[0022] By adopting the above technical solutions, the ceramic coating can protect the metal conductive layer and improve the corrosion resistance, wear resistance, high temperature resistance and other properties of the composite fluid collector, so that the composite fluid collector can better adapt to various harsh environments and provide the environmental applicability of the composite fluid collector products.

[0023] The utility model also provides a lithium ion battery comprising the novel composite current collector described in the above scheme.

[0024] The utility model according to the above scheme has the following beneficial effects:

[0025] The utility model uses the waterproof layer to isolate the external moisture from the polymer polymer layer, and prevents the polymer layer from deteriorating due to the absorption of moisture in the environment, thereby improving the moisture-proof performance of the composite fluid collection; the waterproof layer includes silicone coating and polyurethane coating, and these coating materials have good moisture-proof properties and durability, which can effectively protect the polymer polymer layer from moisture;

[0026] The utility model improves the connection strength between the metal conductive layer and the waterproof layer in the composite fluid by connecting layers, and can form a strong chemical bond between the waterproof layer and the metal conductive layer, thereby improving the connection strength between the laminated structure of the new composite fluid. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the layer arrangement structure of the composite current collector in the utility model;

[0028] Figure 2 It is a partial cross-sectional schematic diagram of the composite current collector in the utility model;

[0029] Figure 3 It is a schematic diagram of the local structure of the composite current collector in the utility model;

[0030] Figure 4 for Figure 3 Enlarged view of part A.

[0031] In the figure,

[0032] 1. Polymer layer; 2. Metal conductive layer; 3. Silicone coating; 4. Polyurethane coating; 5. Sealing layer; 6. Connecting layer; 7. Ceramic coating. DETAILED DESCRIPTION

[0033] In order to better understand the purpose, technical solution and technical effect of the utility model, the utility model is further explained in conjunction with the drawings and embodiments below. It should be noted that similar numbers and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. At the same time, it is stated that the embodiments described below are only used to explain the utility model and are not used to limit the utility model.

[0034] It should be noted that when an element is referred to as "fixed to" or "positioned to" another element, it may be directly on the other element or there may also be a centered element, and when one element is considered to be "connected" another element, it may be directly connected to the other element or there may be a centered element at the same time.

[0035] The indicated orientation or position relationship is based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the product of the application is usually placed when used, or the orientation or position relationship commonly understood by technical personnel in this field, or the orientation or position relationship in which the product of the application is usually placed when used. It is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0036] Embodiment 1

[0037] like Figures 1 to 4 As shown, a novel composite current collector includes a polymer macromolecular layer 1, which is located in the innermost layer as the substrate layer of the current collector; the material of the polymer macromolecular layer 1 is hygroscopic and is easily damp in a high humidity environment. In order to solve this problem, a waterproof layer and a connecting layer 6 are sequentially arranged on both sides of the polymer macromolecular of this embodiment before the metal conductive layer 2 is plated, forming a polymer macromolecular layer 1, a waterproof layer, a connecting layer 6 and a metal conductive layer 2 from the inside to the outside. Since the composite current collector of this embodiment is a double-sided structure, a waterproof layer and a connecting layer 6 are arranged between the composite macromolecular and the metal conductive layers 2 on both sides.

[0038] Among them, the waterproof layer is used to isolate the polymer high molecular layer 1 from the moisture of the external environment, to prevent the polymer high molecular layer 1 from absorbing moisture in the environment and being damp and deteriorating, and the waterproof layer improves the moisture resistance of the polymer high molecular layer of the composite current collector. The connecting layer 6 is composed of a conductive adhesive, and its main function is to form a strong chemical bond between the waterproof layer and the metal conductive layer 2, which can improve the connection strength between the metal conductive layer 2 and the waterproof layer, thereby ensuring that the composite current collector after the waterproof layer is added, its metal conductive layer 2 also has a good connection strength, and the conductive performance of the composite current collector is guaranteed.

[0039] In this embodiment, the material of the polymer polymer layer 1 is polyethylene terephthalate. The thickness of the polyethylene terephthalate layer is 5 microns to 25 microns, and can be selected from 5 microns, 8 microns, 10 microns, 13 microns, 15 microns, 18 microns, 20 microns, 21 microns, 23 microns or 25 microns, etc.

[0040] In this embodiment, the connecting layer 6 is a conductive adhesive layer, and the thickness of the conductive adhesive layer is 2 nanometers to 50 nanometers. According to actual requirements, the thickness of the conductive adhesive layer may be 2 nanometers, 3 nanometers, 5 nanometers, 10 nanometers, 15 nanometers, 20 nanometers, 30 nanometers, 45 nanometers, 50 nanometers, etc.

[0041] In this embodiment, the material of the metal conductive layer 2 is copper. The thickness of the copper layer is 5 nanometers to 100 nanometers, for example, 5 nanometers, 10 nanometers, 15 nanometers, 20 nanometers, 30 nanometers, 45 nanometers, 50 nanometers, 65 nanometers, 74 nanometers, 78 nanometers, 80 nanometers, 95 nanometers, 100 nanometers, etc.

[0042] In this embodiment, the waterproof layer includes a silicone coating 3 and a polyurethane coating 4 , and the silicone coating 3 and the polyurethane coating 4 are arranged in sequence from the inside to the outside, that is, the outer surface of the polymer polymer layer 1 is coated with a silicone coating 3, and the surface of the silicone coating 3 is coated with a polyurethane coating 4 . The silicone coating 3 has good water resistance and sealing properties, and the polyurethane coating 4 has good water resistance, which can effectively protect the polymer polymer layer 1 from moisture.

[0043] Embodiment 2

[0044] A novel composite current collector includes, from inside to outside, a polymer high molecular layer 1, a silicone coating 3, a polyurethane coating 4, a connecting layer 6, and a metal conductive layer 2. The remaining structure is the same as that of the first embodiment, except that a sealing layer 5 is provided at the edge connection of the polymer high molecular layer 1, the silicone coating 3, and the polyurethane coating 4, and the material of the sealing layer is silica gel. The sealing layer 5 can provide moisture-proof protection for the connection between the polymer high molecular layer 1, the silicone coating 3, and the polyurethane coating 4, and further enhance the moisture-proof performance of the composite current collector.

[0045] In this embodiment, the thickness of the polyethylene terephthalate layer is 5 microns to 25 microns, and can be selected from 6 microns, 9 microns, 12 microns, 14 microns, 16 microns, 19 microns, 22 microns, 24 microns or 25 microns, etc.

[0046] In this embodiment, the thickness of the conductive glue layer is 2 nanometers to 50 nanometers. According to actual requirements, the thickness of the conductive glue layer may be 4 nanometers, 6 nanometers, 8 nanometers, 12 nanometers, 14 nanometers, 16 nanometers, 18 nanometers, 22 nanometers, or 25 nanometers, etc.

[0047] In this embodiment, the thickness of the copper layer is 5 nanometers to 100 nanometers, for example, 8 nanometers, 12 nanometers, 18 nanometers, 22 nanometers, 28 nanometers, 35 nanometers, 40 nanometers, 44 nanometers, 53 nanometers, 55 nanometers, 60 nanometers, 68 nanometers, or 70 nanometers, etc.

[0048] Embodiment 3

[0049] A novel composite current collector includes, from inside to outside, a polymer layer 1, a silicone coating 3, a polyurethane coating 4, a connecting layer 6, and a metal conductive layer 2. The remaining structures are the same as those of the first or second embodiment, except that a protective layer is provided on the outer surface of the metal conductive layer 2. The protective layer is a ceramic coating 7, and the thickness of the ceramic coating 7 is 5 nanometers to 50 nanometers, such as 5 nanometers, 10 nanometers, 15 nanometers, 20 nanometers, 25 nanometers, 30 nanometers, 35 nanometers, 40 nanometers, 45 nanometers, or 50 nanometers.

[0050] In this embodiment, the ceramic coating 7 can protect the metal conductive layer 2 , improve the corrosion resistance, wear resistance, high temperature resistance and other properties of the composite fluid collector, so that the composite fluid collector can better adapt to various harsh environments and provide environmental applicability of the composite fluid collector product.

[0051] In summary, the utility model can improve moisture-proof performance by coating a waterproof layer on the surface of the polymer macromolecular layer 1, and can effectively protect the polymer macromolecular layer 1 from being affected by moisture.

[0052] Embodiment 4

[0053] A lithium-ion battery, comprising a pole sheet, the pole sheet comprises a current collector and an active material coated on the current collector. Among them, the current collector is a new composite liquid collector described in Example 1, Example 2 or Example 3.

[0054] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0055] The above embodiments only express several implementation methods of the utility model, and the descriptions are relatively specific and detailed, but they cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A novel composite current collector, comprising an inner polymer layer and metal conductive layers on both sides, characterized in that: A waterproof layer and a connecting layer are provided between the polymer macromolecular layer and the metal conductive layer on each side, and the waterproof layer and the connecting layer are arranged in sequence from the inside to the outside.

2. The novel composite current collector according to claim 1, characterized in that: The waterproof layer includes a silicone coating and a polyurethane coating, and the silicone coating and the polyurethane coating are arranged in sequence from the inside to the outside.

3. The novel composite current collector according to claim 2, characterized in that: A sealing layer is provided at the edge connection of the polymer high molecular layer, the silicone coating and the polyurethane coating.

4. The novel composite current collector according to claim 1, characterized in that: The connecting layer is a conductive adhesive layer.

5. The novel composite current collector according to claim 1, characterized in that: The material of the polymer high molecular layer is polyethylene terephthalate.

6. The novel composite current collector according to claim 1 or 5, characterized in that: The thickness of the polymer layer is 5 micrometers to 25 micrometers.

7. The novel composite current collector according to claim 1, characterized in that: The thickness of the metal conductive layer is 5 nanometers to 100 nanometers.

8. The novel composite current collector according to claim 1 or 7, characterized in that: A protective layer is provided on the outer surface of the metal conductive layer.

9. The novel composite current collector according to claim 8, characterized in that: The protective layer is a ceramic coating, and the thickness of the ceramic coating is 5 nanometers to 50 nanometers.

10. A lithium ion battery, comprising a pole piece, characterized in that: The pole piece comprises the novel composite current collector according to any one of claims 1 to 9.

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