Flexible nanometer composite current collector and lithium ion battery

Abstract

The utility model relates to the technical field of current collectors for lithium ion batteries, in particular to a flexible nano composite current collector and a lithium ion battery, which comprise a base material layer, a plurality of first conductive layers and second conductive layers which are sequentially arranged on two sides of the base material layer, the first conductive layer comprises two deposition materials which are arranged on the same layer at intervals; the second conductive layer comprises two deposition materials which are arranged on the same layer at intervals; wherein the adjacent contact surfaces of the first conducting layer and the second conducting layer are made of dissimilar materials; according to the flexible nano composite current collector and the lithium ion battery disclosed by the utility model, the conductive layers of the current collector are made of different metal materials and are mutually spaced, so that the binding force between the conductive layers and a base material and the overall corrosion resistance of a film layer are effectively improved, and the electrolyte resistance of the film layer is further improved; and meanwhile, the welding compatibility and stability of the current collector tab are also improved, and the cycle life of the lithium battery is indirectly prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of current collectors for lithium - ion batteries, and particularly relates to a flexible nano - composite current collector and a lithium - ion battery. Background Art

[0002] With the continuous development and growth of the new energy industry, the currently commercialized lithium - ion batteries can no longer meet the increasing demands for high safety, high energy density, and power density. As an indispensable component in the battery, the performance of the current collector has a non - negligible impact on the performance of the entire battery. Due to the existence of a relatively thick metal layer, the traditional metal foil current collector affects the energy density of the battery. Compared with metal materials, polymer materials have a lower density and also have relatively high mechanical strength. Therefore, the use of polymer materials is expected to achieve a breakthrough in the performance of the battery in terms of energy density and other aspects.

[0003] In addition, the traditional metal foil current collector is composed of pure metal and has the characteristics of low brittleness and toughness. As a result, in the technological processes under heat and tension environments such as coating, rolling, drying, and slicing, it is prone to problems such as fracture and edge breakage, which easily cause material waste, poor product consistency, and reduced production efficiency. At the same time, considering multiple key factors such as cost, safety, and energy density, the pure metal current collector is no longer the best application carrier. In recent years, many studies have focused on replacing the traditional metal current collector with lightweight flexible metal / plastic composite film materials to achieve higher safety, higher volumetric energy density, and mass energy density for lithium batteries. Currently, composite foils with polymer substrates have been widely studied and applied in mass production.

[0004] The composite current collector obtained by setting a conductive layer on the surface of a low - density polymer film can effectively reduce the density of the current collector of the lithium - ion battery and improve the weight energy density of the lithium - ion battery. However, the above - mentioned composite current collector has the problem of low adhesion between the conductive layer and the polymer film, which leads to phenomena such as the shedding of the surface conductive layer of the composite current collector during the processing of the electrode sheet and the life cycle of the lithium - ion battery, which will seriously affect the cycle life and high - temperature storage performance of the lithium - ion battery.

[0005] Therefore, there is an urgent need for a current collector structure that can enhance the adhesion between the conductive layer and the polymer film. Summary of the Utility Model

[0006] In order to solve the technical problems mentioned in the background art, the utility model provides a flexible nano - composite current collector and a lithium - ion battery:

[0007] In a first aspect, the present utility model provides a flexible nano composite current collector, comprising: a substrate layer, on both sides of which are sequentially provided several stacked first conductive layers and second conductive layers; the first conductive layer comprises two deposition materials arranged at intervals in the same layer; the second conductive layer comprises two deposition materials arranged at intervals in the same layer; wherein the adjacent contact surfaces of the first conductive layer and the second conductive layer are made of different materials.

[0008] Further, the substrate layer is any one of a biaxially oriented polypropylene film, a cast polypropylene film, a polyethylene terephthalate film, a polyimide film, or a polyethylene naphthalate film.

[0009] Further, the thickness of the substrate layer is 3 - 20 μm.

[0010] Further, the first conductive layer is a combination of any two of aluminum, copper, nickel, titanium, silver, gold, cobalt, chromium, molybdenum, tungsten, stainless steel, and alloys of aluminum, copper, nickel, titanium, silver, gold, cobalt, chromium, molybdenum, tungsten, and stainless steel.

[0011] Further, the second conductive layer is a combination of any two of aluminum, copper, nickel, titanium, silver, gold, cobalt, chromium, molybdenum, tungsten, stainless steel, and alloys of aluminum, copper, nickel, titanium, silver, gold, cobalt, chromium, molybdenum, tungsten, and stainless steel.

[0012] Further, the thickness of the first conductive layer is 100 nm - 3 μm.

[0013] Further, the thickness of the second conductive layer is 100 nm - 3 μm.

[0014] In a second aspect, the present utility model provides a lithium ion battery, which uses the flexible nano composite current collector as described above.

[0015] The beneficial effects of the present utility model are that, in the flexible composite current collector and the lithium ion battery of the present utility model, by using different metal materials in the conductive layer of the current collector and spacing them from each other, the bonding force between the conductive layer and the substrate and the overall corrosion resistance of the film layer are effectively improved, thereby improving the electrolyte resistance performance of the film layer. At the same time, the compatibility and stability of the current collector tab welding are also improved, indirectly improving the cycle life of the lithium battery.

[0016] Other features and advantages of the present utility model will be described in the subsequent specification, and some of them will become obvious from the specification or be understood by implementing the present utility model. The objectives and other advantages of the present utility model are achieved and obtained by the structures specifically pointed out in the specification and the drawings.

[0017] To make the above objectives, features, and advantages of the present utility model more obvious and understandable, the following specifically enumerates preferred embodiments and, in conjunction with the accompanying drawings, provides a detailed description as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0019] Figure 1 The structural schematic diagram of the flexible nano-composite current collector involved in some embodiments is shown.

[0020] In the figure:

[0021] Substrate layer 1, first conductive layer 2, second conductive layer 3;

[0022] First material position X1 of the first conductive layer, second material position X2 of the first conductive layer, first material position X3 of the second conductive layer, second material position X4 of the second conductive layer. SPECIFIC EMBODIMENTS

[0023] In order to make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0024] As Figure 1 shown, at least one embodiment provides a flexible nano-composite current collector, including: a substrate layer, on both sides of which are sequentially provided a plurality of stacked first conductive layers and second conductive layers; the first conductive layer includes two deposition materials arranged at intervals in the same layer; the second conductive layer includes two deposition materials arranged at intervals in the same layer; wherein the adjacent contact surfaces of the first conductive layer and the second conductive layer are dissimilar materials.

[0025] In this embodiment, specifically, the first material position X1 of the first conductive layer and the second material position X2 of the first conductive layer are dissimilar materials, the first material position X3 of the second conductive layer and the second material position X4 of the second conductive layer are dissimilar materials, the first material position X1 of the first conductive layer and the first material position X3 of the second conductive layer are dissimilar materials, and the second material position X2 of the first conductive layer and the second material position X4 of the second conductive layer are dissimilar materials.

[0026] In this embodiment, specifically, the substrate layer is any one of a biaxially oriented polypropylene film, a cast polypropylene film, a polyethylene terephthalate film, a polyimide film, or a polyethylene naphthalate film.

[0027] In this embodiment, specifically, the thickness of the substrate layer is 3 - 20 μm, preferably 3, 5, 8, 10, 12, 15, 18, 20 μm.

[0028] In this embodiment, specifically, the first conductive layer is a combination of any two of aluminum, copper, nickel, titanium, silver, gold, cobalt, chromium, molybdenum, tungsten, stainless steel, and their alloys.

[0029] In this embodiment, specifically, the second conductive layer is a combination of any two of aluminum, copper, nickel, titanium, silver, gold, cobalt, chromium, molybdenum, tungsten, stainless steel, and their alloys.

[0030] In this embodiment, specifically, the thickness of the first conductive layer is 100 nm - 3 μm, preferably 100 nm, 250 nm, 500 nm, 1, 1.5, 2, 2.5, 3 μm.

[0031] In this embodiment, specifically, the thickness of the second conductive layer is 100 nm - 3 μm, preferably 100 nm, 250 nm, 500 nm, 1, 1.5, 2, 2.5, 3 μm.

[0032] In this embodiment, specifically, as shown Figure 1 FIG. is only a schematic structural diagram of the flexible nano composite current collector with 3 conductive layers provided on each side. It can be laminated 1 - 40 layers on one side according to the positional relationship between the first conductive layer and the second conductive layer, preferably 1, 3, 5, 10, 15, 20, 25, 30, 35, 40 layers.

[0033] In a second aspect, the present invention provides a lithium - ion battery using the flexible nano composite current collector as described above.

[0034] In summary, for the flexible nano composite current collector and the lithium - ion battery of the present invention, by using different metal materials in the conductive layer of the current collector and spacing them from each other, the bonding force between the conductive layer and the substrate and the overall corrosion resistance of the film layer are effectively improved. Furthermore, the electrolyte resistance performance of the film layer is improved, and at the same time, the compatibility and stability of the current collector tab welding are also improved, indirectly improving the cycle life of the lithium battery.

[0035] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0036] Based on the above inspiration from the ideal embodiments of the present utility model, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of this utility model. The technical scope of this utility model is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A flexible nanocomposite current collector, characterized in that: include: A substrate layer, with a plurality of stacked first conductive layers and second conductive layers sequentially arranged on both sides thereof; The first conductive layer includes two deposited materials spaced apart in the same layer; The second conductive layer includes two deposited materials spaced apart in the same layer; The adjacent contact surfaces of the first conductive layer and the second conductive layer are made of different materials.

2. The flexible nanocomposite current collector according to claim 1, characterized in that: The substrate layer is any one of a biaxially oriented polypropylene film, a cast polypropylene film, a polyethylene terephthalate film, a polyimide film or a polyethylene naphthalate film.

3. The flexible nanocomposite current collector according to claim 1, characterized in that: The thickness of the substrate layer is 3 to 20 μm.

4. The flexible nanocomposite current collector according to claim 1, characterized in that: The deposition material of the first conductive layer is aluminum, copper, nickel, titanium, silver, gold, cobalt, chromium, molybdenum, tungsten, stainless steel, and a combination of any two of aluminum, copper, nickel, titanium, silver, gold, cobalt, chromium, molybdenum, tungsten, and stainless steel alloys.

5. The flexible nanocomposite current collector according to claim 1, characterized in that: The second conductive layer is aluminum, copper, nickel, titanium, silver, gold, cobalt, chromium, molybdenum, tungsten, stainless steel, or a combination of any two of aluminum, copper, nickel, titanium, silver, gold, cobalt, chromium, molybdenum, tungsten, or stainless steel alloys.

6. The flexible nanocomposite current collector according to claim 1, characterized in that: The thickness of the first conductive layer is 100 nm to 3 μm.

7. The flexible nanocomposite current collector according to claim 1, characterized in that: The thickness of the second conductive layer is 100 nm to 3 μm.

8. A lithium ion battery, characterized in that: A flexible nanocomposite current collector as described in any one of claims 1 to 7 is used.

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