JP3239908U - Composite current collector and battery - Google Patents

Abstract

Kind Code: A1 A composite current collector having high adhesive strength between a conductive layer and a base film and being difficult to separate, and a battery comprising the composite current collector are provided.
A composite current collector includes a base film (10), two bonding layers (20), two barrier layers (30), and two conductive layers (40), wherein the base film is a nonmetallic thin film; The bonding layers of the layers are arranged symmetrically with respect to the base film, one is formed on the top surface of the base film and the other is provided on the bottom surface of the base film so as to be sputtered, forming a two-layer barrier. The layers are arranged symmetrically with respect to the base film, one is provided on the upper surface of one bonding layer and the other is provided on the lower surface of the other bonding layer, and the two conductive layers are arranged with respect to the base film. one on top of one barrier layer and the other on the bottom of the other barrier layer.
[Selection drawing] Fig. 1

Description

The present invention belongs to the technical field of current collectors, and specifically relates to composite current collectors and batteries.

A current collector is a member for collecting current in a battery. A normal current collector is made of copper foil or aluminum foil. Due to the large amount used, the application of pure metal current collectors to batteries results in high production costs. At present, we have developed a PET composite current collector and placed a conductive layer on the surface of PET to reduce the weight of the entire current collector. Therefore, the conductive layer is easily separated from the PET.

The present invention is intended to solve at least one of the technical problems existing in the prior art.

Therefore, the present invention proposes a composite current collector which has the advantages of high connection strength between the conductive layer and the base film and resistance to detachment.

A composite current collector according to an embodiment of the present invention comprises a base film, two bonding layers, two barrier layers, and two conductive layers,
The base film is a nonmetallic thin film, and the two bonding layers are arranged symmetrically with respect to the base film, one is formed on the top surface of the base film so as to be sputtered, and the other is formed on the top surface of the base film. is provided on the lower surface of the base film, and the two barrier layers are arranged symmetrically with respect to the base film, one is provided on the upper surface of one of the bonding layers, and the other is provided on the other of the barrier layers. The two conductive layers provided on the lower surface of the bonding layer are arranged symmetrically with respect to the base film, one of which is provided on the upper surface of one of the barrier layers, and the other of which is provided on the other barrier layer. Provided on the lower surface, the material of the conductive layer is different from the barrier layer.

The beneficial effects of the present invention are as follows: the present invention has a simple structure, uses a non-metallic base film as the main body material, reduces the use of metal, and reduces the weight and manufacturing cost of the composite current collector. By placing a bonding layer and a barrier layer between the base film and the conductive layer, the bonding layer metallizes the surface of the base film so that other metals can be processed thereon, and the barrier layer is It can block the occurrence of diffusion reaction between the bonding layer and the conductive layer, and avoid the deterioration of the bonding strength with the base film after the reaction of the bonding layer.

According to one embodiment of the present invention, the conductive layer comprises a seed layer sputtered on the surface of the barrier layer and a metal layer processed on the surface of the seed layer by plating or vapor deposition. .

According to one embodiment of the present invention, the seed layer has a thickness of 2-200 nm, and the metal layer has a thickness of 0.5-5 μm.

According to one embodiment of the present invention, the surface of the metal layer is further provided with a conductive weatherproof layer.

According to one embodiment of the invention, the bonding layer is at least one of the following metals: copper, aluminum, chromium, titanium, vanadium, niobium, cobalt, tungsten, molybdenum, zinc, nickel and alloys thereof; The bonding layer has a thickness of 2 to 50 nm.

According to one embodiment of the invention, the barrier layer is at least one of the following metals: copper, aluminum, chromium, tin, cobalt, tungsten, zinc, nickel and alloys thereof, and the thickness of the barrier layer is is between 2 and 50 nm.

According to one embodiment of the present invention, the substrate layer is one of PET, PP, PI, PC, PMMA, and the thickness of the substrate layer is 2-15 μm.

According to one embodiment of the invention, the conductive layer is at least one of copper, aluminum, lithium, gold, silver, titanium, molybdenum, zinc and nickel.

According to one embodiment of the invention, the weathering layer is made of metals of copper, aluminum, lithium, gold, silver, titanium, chromium, tin, cobalt, tungsten, molybdenum, zinc, nickel, alloys thereof, metal oxides thereof. , and an organic antioxidant, and the weather resistant layer has a thickness of 1 to 100 nm.

According to one embodiment of the invention, a battery comprises the above composite current collector.

In the following description, some additional aspects and advantages of the invention will be set forth, and others will become apparent from the description below or may be learned by practice of the invention.

These and/or additional aspects and advantages of the present invention will become apparent and comprehensible in the following description of the embodiments in conjunction with the figures.
1 is a structural schematic diagram of a composite current collector according to an embodiment of the present invention; FIG.

In the description of the present invention, the terms "center", "vertical direction", "horizontal direction", "length", "width", "thickness", "top", "bottom", "front", " Rear", "Left", "Right", "Vertical", "Horizontal", "Ceiling", "Bottom", "Inner", "Outer", "Clockwise", "Counterclockwise", "Axial", An indicated orientation or relationship such as "radial", "circumferential", etc., indicates or implies that the indicated device or element has a particular orientation and must be constructed and operated in a particular orientation. However, it is not a limitation on the present invention, merely for convenience of describing the present invention and for simplification of description. Also, a feature that is limited to "first" and "second" includes either explicitly or implicitly one or more of such features. In the description of the present invention, "plurality" means two or more, unless stated otherwise.

In the description of the present invention, the terms "attachment", "coupling", "connection" should be understood broadly, unless otherwise explicitly defined and limited, e.g. It may be a possible connection or an integral connection, a mechanical connection, an electrical connection, a direct connection, an indirect connection through an intermediate medium, or a communication within the two elements. Those skilled in the art should understand the specific meaning of the above terms in the present invention based on specific cases.

Composite current collectors according to embodiments of the present invention will be specifically described below.

As shown in FIG. 1, the composite current collector according to the embodiment of the present invention comprises a base film 10, two bonding layers 20, two barrier layers 30 and two conductive layers 40, and the base film 10 is a non-metal thin film, and two bonding layers 20 are arranged symmetrically with respect to the base film 10, one is formed on the upper surface of the base film 10 so as to be sputtered, and the other is formed on the base film. Two barrier layers 30 are provided on the lower surface of the material film 10 and are arranged symmetrically with respect to the base film 10. One is provided on the upper surface of one bonding layer 20, and the other is provided on the other bonding layer 20. Provided on the lower surface, the two conductive layers 40 are arranged symmetrically with respect to the base film 10, one is provided on the upper surface of one barrier layer 30, and the other is provided on the lower surface of the other barrier layer 30. provided, the material of the conductive layer 40 is different from the barrier layer 30 .

The structure of the present invention is simple, the non-metallic base film 10 is used as the main material, the use of metal is reduced, the weight and manufacturing cost of the composite current collector are reduced, and the base film 10 and the conductive The bonding layer 20 and the barrier layer 30 are arranged between the layers 40, the bonding layer 20 metallizes the surface of the base film 10, and other metals can be processed thereon, and the barrier layer 30 is the bonding layer 20 and the conductive layer. It can block the occurrence of diffusion reaction with 40, and avoid the deterioration of the bonding strength with the base film 10 after the bonding layer 20 reacts.

According to one embodiment of the present invention, the conductive layer 40 comprises a seed layer 41 sputtered on the surface of the barrier layer 30 and a metal layer 42 processed on the surface of the seed layer 41 by plating or vapor deposition. , provided. Preferably, the seed layer 41 has a thickness of 2-200 nm. More preferably, the thickness of the metal layer 42 is 0.5-5 μm. The seed layer 41 and the metal layer 42 are made of the same kind of metal, and the metal layer 42 is thick. A single seed layer 41 is processed so that the seed layer 41 can quickly process the metal layer 42 in subsequent plating or vapor deposition processes.

According to one embodiment of the present invention, the surface of the metal layer 42 is further provided with an electrically conductive weatherproof layer 50 . The weathering layer 50 is at least one of the following metals: copper, aluminum, lithium, gold, silver, titanium, chromium, tin, cobalt, tungsten, molybdenum, zinc, nickel, alloys thereof, metal oxides thereof, and organic antioxidants. and the weather-resistant layer 50 has a thickness of 1 to 100 nm.

The main function of the weather-resistant layer 50 in the present invention is to protect the conductive layer 40 from corrosion. Nickel, copper alloys, aluminum alloys, lithium alloys, gold alloys, silver alloys, titanium alloys, chromium alloys, tin alloys, cobalt alloys, tungsten alloys, molybdenum alloys, zinc alloys, nickel alloys, copper metal oxides, aluminum metals oxide, lithium metal oxide, gold metal oxide, silver metal oxide, titanium metal oxide, chromium metal oxide, tin metal oxide, cobalt metal oxide, tungsten metal oxide , molybdenum metal oxides, zinc metal oxides, nickel metal oxides, and conductive organic antioxidants.

Based on this, the bonding layer 20 is at least one of the following metals: copper, aluminum, chromium, titanium, vanadium, niobium, cobalt, tungsten, molybdenum, zinc, nickel and alloys thereof, and the thickness of the bonding layer 20 is is between 2 and 50 nm. That is, the bonding layer 20 includes copper, aluminum, chromium, titanium, vanadium, niobium, cobalt, tungsten, molybdenum, zinc, nickel, copper alloy, aluminum alloy, chromium alloy, titanium alloy, vanadium alloy, niobium alloy, cobalt alloy, and tungsten. at least one of an alloy, a molybdenum alloy, a zinc alloy, and a nickel alloy.

In one preferred embodiment of the present invention, barrier layer 30 is at least one of the following metals: copper, aluminum, chromium, tin, cobalt, tungsten, zinc, nickel and alloys thereof, and the thickness of barrier layer 30 is is between 2 and 50 nm. In other words, barrier layer 30 is made of at least one of copper, aluminum, chromium, tin, cobalt, tungsten, zinc, nickel, copper alloys, aluminum alloys, chromium alloys, tin alloys, cobalt alloys, tungsten alloys, zinc alloys, and nickel alloys. One.

According to one embodiment of the present invention, the substrate layer 10 is one of PET, PP, PI, PC, PMMA, and the thickness of the substrate layer 10 is 2-15 μm. The weight of the substrate layer 10 is much smaller than that of the metal material, effectively reducing the weight of the composite current collector and further reducing the weight of the battery using the composite current collector. Since the shrinkage rate of the base layer 10 is small, the shedding of the active material due to the shrinkage of the copper foil or the aluminum foil is reduced, and the cycle life of the battery is extended.

According to one embodiment of the invention, conductive layer 40 is at least one of copper, aluminum, lithium, gold, silver, titanium, molybdenum, zinc and nickel. Preferably, the conductive layer 40 is a single metal and has good conductive effect. The suitable conductive layer 40 material for different batteries is different. For lithium batteries, the conductive layer 40 is generally copper when the composite current collector is applied to the negative electrode, and the conductive layer 40 is generally copper when the composite current collector is applied to the positive electrode. , the conductive layer 40 is typically aluminum.

The present invention further discloses a battery comprising the above composite current collector. Compared to copper foil or aluminum foil, the overall thickness of the composite current collector is significantly reduced, reducing the weight of the battery using the composite current collector and improving the energy density.

The present invention further discloses a vehicle comprising the above battery. For electric vehicles, it reduces the overall mass of the vehicle.

Comparative example 1
The substrate layer 10 is PET with a thickness of 4.5μ, the conductive layer 40 is copper with a thickness of 1μ, and the conductive layer 40 is directly provided on the substrate layer 10 .

Comparative example 2
The substrate layer 10 is PET with a thickness of 4.5 microns, the bonding layer 20 is chromium with a thickness of 20 nm, and the conductive layer 40 is copper with a thickness of 1 micron, compared to Comparative Example 1. And Comparative Example 2 adds a bonding layer 20 .

Example 1
The substrate layer 10 is PET with a thickness of 4.5 microns, the bonding layer 20 is chromium with a thickness of 20 nm, the barrier layer 30 is Ni80Cr20 with a thickness of 15 nm, and the conductive layer 40 is 1 micron. is copper with a thickness of Compared to Comparative Example 2, Example 1 adds a barrier layer 30 . During processing, the parameters of the sputtering apparatus are as follows. The conveying speed is 2 m/min, the sputtering power for the bonding layer 20 is 4 KW, the sputtering power for the barrier layer 30 is 3 KW, the sputtering power for the seed layer 41 is 3 KW, and the seed layer 41 is sputtered six times. Sputtering. Ni80Cr20 is a resistance electrothermal alloy, the structure and electrophysical properties of such an alloy are stable, the high temperature mechanical properties are good, the cold deformation plasticity and weldability are excellent. No destruction occurs.

The substrate layer 10 and the conductive layer 40 in Comparative Example 1, Comparative Example 2, and Example 1 are the same, and the bonding layer 20 in Comparative Example 2 and Example 1 are the same. Based on the test method in IPC-TM-650 2.4.8, a peel strength test was performed on Comparative Example 1, Comparative Example 2, and Example 1 (here, the thickness of the composite current collector of the present invention Since the thickness is thin, it is not possible to directly test in Comparative Examples 1, 2, and 1. Therefore, before the test, the conductive layer 40 is thickened to a predetermined thickness, and then the test is performed. The peel strength of Comparative Example 1 is 0.2 to 0.4 kgf/cm, the peel strength of Comparative Example 2 is 0.4 to 0.7 kgf/cm, and the peel strength of Example 1 is 0.5 to 0.8 kgf/cm. Simulating the usage environment of the battery for Comparative Example 1, Comparative Example 2, and Example 1, the peel strength was tested at a temperature of 70 ° C for 500 hours, and the peel strength of Comparative Example 1 was tested. <0.2 kgf/cm, the peel strength of Comparative Example 2 is 0.2 to 0.4 kgf/cm, and the peel strength of Example 1 is 0.4 to 0.7 kgf/cm. As can be seen from this, after the test, a diffusion reaction occurred in the connecting portion between the conductive layer 40 and the bonding layer 20, so that the bonding strength between the bonding layer 20 and the base layer 10 was reduced. , effectively avoid the occurrence of reaction between the conductive layer 40 and the bonding layer 20 . In the present application, by disposing the barrier layer 30 between the bonding layer 20 and the conductive layer 40, the connection strength between the entire bonding layer 20 and the base layer 10 is effectively improved, and the service life of the composite current collector is extended. extend the

In the description herein, the terms “one embodiment,” “some embodiments,” “schematic examples,” “exemplification,” “specific examples,” or “some References such as "exemplary" indicate that at least one embodiment or example of the present invention includes the particular feature, structure, material, or feature described in conjunction with that example or example. In this specification, schematic representations for such terms do not necessarily refer to the same embodiment or illustration. And the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or illustrations.

While embodiments of the invention have been illustrated and described, it will be appreciated by those skilled in the art that various alterations, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the invention. Instead, the scope of the invention is defined by the claims and their equivalents.

10 base film,
20 bonding layer,
30 barrier layer,
40 conductive layer,
50 weathering layer,
41 seed layer,
42 metal layer

Claims (10)

A composite current collector,
comprising a substrate film (10), two bonding layers (20), two barrier layers (30), and two conductive layers (40),
The base film (10) is a nonmetallic thin film,
The two bonding layers (20) are arranged symmetrically with respect to the base film (10), one is formed on the upper surface of the base film (10) so as to be sputtered, and the other is Provided on the lower surface of the base film (10),
The two barrier layers (30) are arranged symmetrically with respect to the base film (10), one is provided on the upper surface of one of the bonding layers (20), and the other is provided on the other of the bonding layers. (20) provided on the lower surface,
The two conductive layers (40) are arranged symmetrically with respect to the base film (10), one being provided on top of one of the barrier layers (30) and the other being provided on the other barrier layer. A composite current collector provided on the underside of (30), characterized in that the material of said conductive layer (40) is different from said barrier layer (30). The conductive layer (40) includes a seed layer (41) sputtered on the surface of the barrier layer (30) and a metal layer (42) processed on the surface of the seed layer (41) by plating or vapor deposition. ), and the composite current collector of claim 1, wherein: A composite current collector according to claim 2, characterized in that the seed layer (41) has a thickness of 2-200 nm and the metal layer (42) has a thickness of 0.5-5 µm. 3. The composite current collector according to claim 2, wherein a conductive weather resistant layer (50) is further provided on the surface of the metal layer (42). The bonding layer (20) is at least one of copper, aluminum, chromium, titanium, vanadium, niobium, cobalt, tungsten, molybdenum, zinc, nickel and alloys thereof, and the thickness of the bonding layer (20) is 2. The composite current collector according to claim 1, wherein the thickness is 2 to 50 nm. The barrier layer (30) is at least one of copper, aluminum, chromium, tin, cobalt, tungsten, zinc, nickel and alloys thereof, and the thickness of the barrier layer (30) is 2-50 nm. The composite current collector according to claim 1, characterized in that: 2. The method according to claim 1, wherein the base film (10) is one of PET, PP, PI, PC, PMMA, and the thickness of the base film (10) is 2-15 μm. A composite current collector as described. A composite current collector according to claim 6, wherein said conductive layer (40) is at least one of copper, aluminum, lithium, gold, silver, titanium, molybdenum, zinc and nickel. The weather-resistant layer (50) comprises copper, aluminum, lithium, gold, silver, titanium, chromium, tin, cobalt, tungsten, molybdenum, zinc, nickel metals, alloys thereof, metal oxides thereof, and organic antioxidants. and the thickness of the weather resistant layer (50) is 1 to 100 nm. A battery comprising the composite current collector according to any one of claims 1 to 9.

Images