Composite current collector with undeepened color

Abstract

The composite current collector comprises a supporting layer, a metal conducting layer is arranged on the surface of the supporting layer, the metal conducting layer comprises a metal inner layer and a metal outer layer, the metal inner layer is arranged on the surface of the supporting layer, and the metal outer layer is arranged on the surface of the supporting layer. The metal outer layer is arranged on the surface of the metal inner layer, the metal inner layer is located between the supporting layer and the metal outer layer, the metal outer layer comprises a first metal layer and a second metal layer, the first metal layer is located on the inner side of the metal outer layer, the second metal layer is located on the outer side of the metal outer layer, and the first metal layer is located on the inner side of the metal inner layer. The first metal layer is clamped between the metal inner layer and the second metal layer, the second metal layer is an oxidizable metal layer, and the compactness of the first metal layer is higher than that of the second metal layer. According to the utility model, oxygen can be prevented from further oxidizing the first metal layer, so that the color of the composite current collector is prevented from deepening.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of current collector, especially to a composite current collector without color deepening. BACKGROUND

[0002] Compared with traditional metal aluminum foil and copper foil current collector, the composite current collector is lighter in quality, reduces the use of non-active materials in the battery, and thus improves the energy density of the battery. Meanwhile, its special structure also enhances the mechanical strength of the battery and the metal-polymer interface adhesion. Application prospect: the composite current collector has a wide application prospect in the field of lithium ion batteries and is regarded as the next generation of alternative to traditional metal current collector.

[0003] The composite current collector is currently developing rapidly, but no manufacturer can realize mass production at present. The main reason is that the composite current collector will have a series of problems after production, one of which is that the composite current collector itself will deepen in color after production or storage for a period of time. Therefore, the prior art still needs to be improved and enhanced. UTILITY MODEL CONTENT

[0004] In view of the above shortcomings of the prior art, the purpose of the utility model is to provide a composite current collector without color deepening.

[0005] To solve the above technical problems, the utility model adopts the following technical scheme:

[0006] The utility model provides a composite current collector without color deepening, which comprises a supporting layer, a metal conducting layer is arranged on the surface of the supporting layer, the metal conducting layer comprises a metal inner layer and a metal outer layer, the metal inner layer is arranged on the surface of the supporting layer, the metal outer layer is arranged on the surface of the metal inner layer, the metal inner layer is located between the supporting layer and the metal outer layer, the metal outer layer comprises a first metal layer and a second metal layer, the first metal layer is located on the inner side of the metal outer layer, the second metal layer is located on the outer side of the metal outer layer, the first metal layer is clamped between the metal inner layer and the second metal layer, the second metal layer is an oxidizable metal layer, and the compactness of the first metal layer is higher than that of the second metal layer.

[0007] Further, the second metal layer and the metal inner layer are layers of the same metal material.

[0008] Further, the second metal layer is a metal copper layer or a metal aluminum layer, and the metal inner layer is a metal copper layer or a metal aluminum layer.

[0009] Further, the first metal layer and the metal inner layer are layers of the same metal material.

[0010] Further, the color non-deepening composite current collector, the mass of the second metal layer is less than the mass of the first metal layer, and the mass of the second metal layer is less than the mass of the metal inner layer.

[0011] Further, the color non-deepening composite current collector, the mass of the first metal layer is less than the mass of the metal inner layer.

[0012] Further, the color non-deepening composite current collector, the thickness of the second metal layer is 10-30 nm.

[0013] Further, the color non-deepening composite current collector, the metal inner layer includes a first inner layer and a second inner layer, the first inner layer is located between the support layer and the second inner layer, the first inner layer is a metal layer, the first inner layer is a nickel alloy, titanium alloy, copper alloy or aluminum alloy layer, and the second inner layer and the second metal layer are layers of the same metal material.

[0014] Further, the color non-deepening composite current collector, the metal inner layer includes a first inner layer and a second inner layer, the first inner layer is located between the support layer and the second inner layer, the first inner layer is a non-metal layer, the first inner layer is an aluminum oxide, silicon nitride or silicon carbide layer, and the second inner layer and the second metal layer are layers of the same metal material.

[0015] Specifically, the color non-deepening composite current collector, the mass of the metal conductive layer is less than the mass of the support layer, the thickness of the support layer is 3-8 um, and the support layer is a film formed of one or more of polyamide, polyimide, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyethylene, polypropylene, polypropylene, acrylonitrile-butadiene-styrene copolymer, polyvinyl alcohol, polystyrene, polyvinyl chloride, polyvinylidene fluoride, polytetrafluoroethylene, polystyrene sulfonate sodium, polyacetylene, silicone rubber, polyformaldehyde, polyphenylene ether, polyphenylene sulfide, polyethylene glycol, polythiophene, polystyrene, polyaniline, polythiophene, polythiophene, cellulose, starch, protein, epoxy resin, and phenolic resin.

[0016] Compared with the prior art, the composite current collector provided by the utility model does not deepen in color, and comprises a support layer, a metal conducting layer is arranged on the surface of the support layer, the metal conducting layer comprises a metal inner layer and a metal outer layer, the metal inner layer is arranged on the surface of the support layer, the metal outer layer is arranged on the surface of the metal inner layer, the metal inner layer is located between the support layer and the metal outer layer, the metal outer layer comprises a first metal layer and a second metal layer, the first metal layer is located on the inner side of the metal outer layer, the second metal layer is located on the outer side of the metal outer layer, the first metal layer is clamped between the metal inner layer and the second metal layer, the second metal layer is an oxidizable metal layer, and the compactness of the first metal layer is higher than that of the second metal layer. The second metal layer of the utility model is oxidized to form an oxide with loose structure under the action of the outside world, and after the oxide is formed, oxygen continues to form inside, which leads to deepening of the color of the composite current collector, and the compactness of the first metal layer of the utility model is high, so that oxygen cannot enter, thereby preventing the color of the composite current collector from deepening. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below, and obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can be obtained according to the structures shown in these drawings without creative labor.

[0018] Figure 1 The structure diagram of the composite current collector not deepening in color provided by the utility model.

[0019] DESCRIPTION OF DRAWINGS:

[0020] Support layer 100

[0021] Metal conducting layer 200

[0022] Metal outer layer 210

[0023] Metal inner layer 220

[0024] First metal layer 211

[0025] Second metal layer 212

[0026] First inner layer 221

[0027] Second inner layer 222 DETAILED DESCRIPTION

[0028] Clearly and completely describe the technical solutions in the embodiments of the present application in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0029] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative positional relationship, movement condition, etc. between components in a certain specific posture (as shown in the drawings). If the specific posture changes, the directional indications also change accordingly.

[0030] In addition, if the embodiments of the present application involve descriptions such as "first", "second", etc., the descriptions of "first", "second", etc. are only for description purposes, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but must be based on the realization of those skilled in the art. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope required by the present application.

[0031] For example, Figure 1As shown, the utility model provides a composite current collector with non-deepening color, including a support layer 100, a metal conductive layer 200 is arranged on the surface of the support layer 100, and the metal conductive layer 200 includes a metal inner layer 220 and a metal outer layer 210, the metal inner layer 220 is arranged on the surface of the support layer 100, and the metal outer layer 210 is arranged on the surface of the metal inner layer 220, the metal inner layer 220 is located between the support layer 100 and the metal outer layer 210, the metal outer layer 210 includes a first metal layer 211 and a second metal layer 212, the first metal layer 211 is located on the inner side of the metal outer layer 210, and the second metal layer 212 is located on the outer side of the metal outer layer 210, the first metal layer 211 is sandwiched between the metal inner layer 220 and the second metal layer 212, the second metal layer 212 is an oxidizable metal layer, and the density of the first metal layer 211 is higher than the density of the second metal layer 212. The second metal layer 212 of the present invention oxidizes under external influences to form a fluffy oxide. Once the oxide is formed, oxygen continues to flow inward, causing the color of the composite current collector to darken. However, the first metal layer 211 of the present invention is highly dense, preventing oxygen from entering. This prevents further oxidation of the first metal layer 211, thereby preventing the color of the composite current collector from darkening. The support layer 100 has two surfaces in the thickness direction, both of which are provided with a metal conductive layer 200.

[0032] Furthermore, the composite current collector provided by the present invention does not deepen in color, and the second metal layer 212 and the metal inner layer 220 are made of the same metal material. Furthermore, the composite current collector provided by the present invention does not deepen in color, and the second metal layer 212 is a metal copper layer or a metal aluminum layer, and the metal inner layer 220 is a metal copper layer or a metal aluminum layer. That is to say, the second metal layer 212 and the metal inner layer 220 are made of the same material, for example, they can be both aluminum or both copper. The materials of the first metal layer 211 and the metal inner layer 220 can be different, but in the present invention, they are preferably made of the same material, that is, the first metal layer 211 and the metal inner layer 220 are also made of the same metal material, which is convenient for forming the first metal layer 211 on the metal inner layer 220 during processing.

[0033] Further, the color non-deepening composite current collector provided by the utility model, the mass of the second metal layer 212 is less than the mass of the first metal layer 211, which can be conducive to reducing the weight of the composite current collector, and the mass of the second metal layer 212 is less than the mass of the metal inner layer 220, which is conducive to further reducing the mass of the composite current collector. Further, the color non-deepening composite current collector provided by the utility model, the mass of the first metal layer 211 is less than the mass of the metal inner layer 220, which is also conducive to further reducing the mass of the composite current collector. The mass of the metal layer of the utility model can be less than the mass of the support layer 100, so that the total mass of the composite current collector is smaller, so that the electric device using the utility model, such as a lithium battery, can be lighter in mass and higher in energy density.

[0034] Further, the color non-deepening composite current collector provided by the utility model, the thickness of the second metal layer 212 is 10nm-30nm. If the second metal layer 212 is formed on the first metal layer 211 in a magnetron sputtering mode, since the magnetron sputtering energy is high, the second metal layer 212 can be combined more closely with the first metal layer 211, and the speed of oxidation of the second metal layer 212 can be slowed down.

[0035] Further, the color non-deepening composite current collector provided by the utility model, the metal inner layer 220 comprises a first inner layer 221 and a second inner layer 222, the first inner layer 221 is located between the support layer 100 and the second inner layer 222, the first inner layer 221 is a metal layer, the first inner layer 221 is a nickel alloy layer, a titanium alloy layer, a copper alloy layer or an aluminum alloy layer, and the second inner layer 222 and the second metal layer 212 are same-metal material layers. Alternatively, the color non-deepening composite current collector provided by the utility model, the metal inner layer 220 comprises a first inner layer 221 and a second inner layer 222, the first inner layer 221 is located between the support layer 100 and the second inner layer 222, the first inner layer 221 is a non-metal layer, the first inner layer 221 is an aluminum oxide layer, a silicon nitride layer or a silicon carbide layer, and the second inner layer 222 and the second metal layer 212 are same-metal material layers. The first inner layer 221 can adopt metal or non-metal.

[0036] In the utility model, the thickness of the support layer 100 is 3um-8um, and such thickness can reduce the mass of the composite current collector, and the support layer 100 is made of non-conductive material, which greatly improves the safety performance compared with the pure metal current collector.In the embodiment, the thickness of the first inner layer 221 can be 30-100nm, and the total thickness of the second inner layer 222, the first metal layer 211 and the second metal layer 212 is 900-1000nm, and the total thickness of the second inner layer 222, the first metal layer 211 and the second metal layer 212 can make the flow capacity of the composite current collector meet the requirements, and the thickness of the first inner layer 221 can reduce the weight, and meanwhile, the plating frequency required when the thickness exceeds the thickness will also increase, and the increased plating frequency will increase the probability of the support layer becoming brittle, because the more the plating frequency is, the support layer 100 will be repeatedly heated, which can make the support layer become brittle.

[0037] Specifically, the composite current collector without color deepening provided by the utility model has the mass of the metal conducting layer 200 less than the mass of the support layer 100, the thickness of the support layer 100 is 3um-8um, and the support layer 100 is formed of one or more of the following materials: polyamide, polyimide, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyethylene, polypropylene, polypropylene, acrylonitrile-butadiene-styrene copolymer, polyvinyl alcohol, polystyrene, polyvinyl chloride, polyvinylidene fluoride, polytetrafluoroethylene, polystyrene sodium sulfonate, polyacetylene, silicone rubber, polyformaldehyde, polyphenyl ether, polyphenyl sulfide, polyethylene glycol, polyazolium high polymer material, polystyrene, polypyrrole, polyaniline, polythiophene, poly pyridine, cellulose, starch, protein, epoxy resin and phenolic resin.

[0038] In summary, the second metal layer of the utility model will be oxidized to form a loose structure of oxide under the action of the outside world, and when the oxide is formed, oxygen will continue to form inside, which leads to the deepening of the color of the composite current collector, and the first metal layer of the utility model has high compactness, so oxygen cannot enter, which can prevent oxygen from further oxidizing the first metal layer, thereby preventing the color of the composite current collector from deepening.

[0039] The above only describes the preferred embodiments of the utility model, and does not limit the patent range of the utility model, and any equivalent structural transformation made by using the utility model specification and the drawings, or direct / indirect application in other related technical fields is included in the patent protection range of the utility model.

Claims

1. A non-deepening composite current collector, characterized by, The support layer has a metal conductive layer on its surface, the metal conductive layer comprises a metal inner layer and a metal outer layer, the metal inner layer is arranged on the surface of the support layer, the metal outer layer is arranged on the surface of the metal inner layer, the metal inner layer is between the support layer and the metal outer layer, the metal outer layer comprises a first metal layer and a second metal layer, the first metal layer is on the inner side of the metal outer layer, the second metal layer is on the outer side of the metal outer layer, the first metal layer is sandwiched between the metal inner layer and the second metal layer, the second metal layer is an oxidizable metal layer, and the compactness of the first metal layer is higher than that of the second metal layer.

2. The non-diffusing composite current collector of claim 1, wherein, The second metal layer and the metal inner layer are the same metal material layer.

3. The non-diffusing composite current collector of claim 2, wherein, The second metal layer is a metal copper layer or a metal aluminum layer, and the metal inner layer is a metal copper layer or a metal aluminum layer.

4. The non-diffusing composite current collector of claim 3, wherein, The first metal layer and the metal inner layer are the same metal material layer.

5. The non-diffusing composite current collector of claim 4, wherein, The mass of the second metal layer is less than the mass of the first metal layer, and the mass of the second metal layer is less than the mass of the metal inner layer.

6. The non-diffusing composite current collector of claim 5, wherein, The mass of the first metal layer is less than the mass of the metal inner layer.

7. The non-diffusing composite current collector of claim 6, wherein, The thickness of the second metal layer is 10-30 nm.

8. The non-diffusing composite current collector of claim 7, wherein, The metal inner layer comprises a first inner layer and a second inner layer, the first inner layer is between the support layer and the second inner layer, the first inner layer is a metal layer, the first inner layer is a nickel alloy, titanium alloy, copper alloy or aluminum alloy layer, and the second inner layer and the second metal layer are the same metal material layer; or the metal inner layer comprises a first inner layer and a second inner layer, the first inner layer is between the support layer and the second inner layer, the first inner layer is a non-metal layer, the first inner layer is an aluminum oxide, silicon nitride or silicon carbide layer, and the second inner layer and the second metal layer are the same metal material layer.

9. The non-diffusing composite current collector of claim 8, wherein, The thickness of the first inner layer is 30-100 nm, and the total thickness of the second inner layer, the first metal layer and the second metal layer is 900-1000 nm.

10. The non-diffusing composite current collector of any of claims 1-9, wherein, The mass of the metal conductive layer is less than the mass of the support layer, the thickness of the support layer is 3-8 um, and the support layer is a film formed by polyamide, polyimide, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyethylene, polypropylene, polypropylene, acrylonitrile-butadiene-styrene copolymer, polyvinyl alcohol, polystyrene, polyvinyl chloride, polyvinylidene fluoride, polytetrafluoroethylene, polystyrene sulfonate sodium, polyacetylene, silicone rubber, polyformaldehyde, polyphenylene ether, polyphenylene sulfide, polyethylene glycol, polythiophene, polystyrene, polyaniline, polythiophene, polythiophene, cellulose, starch, protein, epoxy resin or phenolic resin.

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