A current collector, a preparation method and application thereof
By using a combination of non-porous rolled metal foil and fine-grained current collector layer, the problem of delamination and cracking of current collectors during processing and lamination was solved, improving the reliability and production yield of solid-state batteries and extending battery life.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- YANGZHOU NANOPORE INNOVATIVE MATERIALS TECH LTD
- Filing Date
- 2026-03-18
- Publication Date
- 2026-06-09
Smart Images
Figure CN122177846A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of battery manufacturing technology, and relates to a current collector, and more particularly to a current collector and its preparation method and application. Background Technology
[0002] Solid-state batteries are a battery technology that uses solid electrolytes. Compared with traditional lithium-ion batteries, they have advantages such as high safety, high energy density, strong temperature adaptability, and small size and weight. With these performance advantages, they have become an important research direction in the field of battery technology.
[0003] To further improve the core performance of solid-state batteries, especially energy density and safety, solid-state batteries typically employ a current collector design. This current collector must meet key technical requirements such as high conductivity, good compatibility with solid electrolytes, and sufficient mechanical strength.
[0004] Structurally, solid-state batteries mainly consist of positive electrode materials, current collectors, negative electrode materials, solid electrolytes, and encapsulation materials. These components are tightly bonded together after lamination to form a stacked structure. However, under the current technology, the current collector faces two major problems that directly restrict the development of solid-state batteries: First, during processing, the current collector is prone to breakage due to insufficient strength or poor plasticity, preventing it from functioning properly and affecting battery production yield. Second, due to the differences in mechanical properties among the various components of a solid-state battery (positive electrode layer, negative electrode layer, and current collector), the deformation degree of each layer varies during lamination, easily leading to interlayer stress concentration and delamination cracking, severely affecting the reliability and lifespan of the solid-state battery.
[0005] Therefore, how to provide a current collector and its preparation method to improve the reliability and production yield of solid-state batteries and extend the battery's lifespan has become an urgent problem to be solved by those skilled in the art. Summary of the Invention
[0006] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a current collector and its preparation method and application, which can alleviate the delamination and cracking phenomenon between different metal layers, thereby improving the reliability and production yield of solid-state batteries and extending the service life of batteries.
[0007] To achieve this objective, the present invention employs the following technical solution: In a first aspect, the present invention provides a current collector composed of at least two metal layers, including a current collector layer and a functional layer stacked together, wherein the current collector layer includes a positive current collector layer and / or a negative current collector layer.
[0008] The current collector layer is prepared by at least one of magnetron sputtering, electroplating or vapor deposition, and the functional layer is made of non-porous rolled metal foil.
[0009] This invention uses a non-porous rolled metal foil as the functional layer. Because the grains of the rolled metal are elongated along the rolling direction, forming a flat or fibrous structure, the grain size in the thickness direction is significantly reduced, exhibiting obvious grain orientation. Furthermore, its tensile properties are anisotropic, exhibiting high strength and low elongation in the MD and TD directions. Simultaneously, a current collector layer with fine grains is selectively fabricated on its surface using magnetron sputtering, electroplating, or vapor deposition methods, effectively matching the mechanical properties of the functional layer. By enhancing the matching degree of plastic deformation capacity, the delamination and cracking phenomenon between different metal layers is effectively alleviated, thereby improving the reliability and production yield of solid-state batteries and extending the battery's lifespan.
[0010] Preferably, the positive current collector layer is attached to the surface of the functional layer, and the negative current collector layer and the functional layer are the same metal layer made of the same material.
[0011] Preferably, the negative current collector layer is attached to the surface of the functional layer, and the positive current collector layer and the functional layer are the same metal layer made of the same material.
[0012] Preferably, the grain size of the current collector layer and the functional layer are each independently 0.2-2 μm.
[0013] Preferably, the grain aspect ratio of the current collector layer is (2-20):1.
[0014] Preferably, the thickness ratio of the current collection layer to the functional layer is 1:(10-50).
[0015] Preferably, the current collector further includes a composite layer, the number of layers of the composite layer is ≥1, the composite layer is disposed on the surface of the functional layer away from the current collector layer, the grain aspect ratio of the composite layer is (5-10):1; the thickness ratio of the current collector layer, the functional layer and the composite layer is 1:(10-20):(2-5).
[0016] Preferably, the material of the functional layer includes at least one of aluminum, copper or stainless steel, more preferably aluminum and / or copper, and even more preferably aluminum.
[0017] Preferably, the thickness of the functional layer is 10-50 μm.
[0018] Preferably, the positive current collector layer is made of aluminum.
[0019] Preferably, the thickness of the positive current collector layer is 0.1-50 μm, and more preferably 0.1-10 μm.
[0020] Preferably, the negative electrode current collector is made of copper and / or nickel, and more preferably copper.
[0021] Preferably, the thickness of the negative electrode current collector layer is 0.1-50 μm, and more preferably 0.1-10 μm.
[0022] Preferably, a protective layer is also provided on the surface of the current collection layer away from the functional layer.
[0023] Preferably, the material of the protective layer includes at least one of nickel, chromium, nickel-based alloys, copper-based alloys, copper oxide, aluminum oxide, silicon oxide, nickel oxide, chromium oxide, cobalt oxide, graphite, carbon black, copper chromate, copper chromite, carbon nanotubes, carbon nanofibers, or graphene.
[0024] Preferably, the thickness of the protective layer is 5-100 nm, and more preferably 10-80 nm.
[0025] Preferably, the total thickness of the current collector is 10-100 μm.
[0026] In a second aspect, the present invention provides a method for preparing a current collector as described in the first aspect, comprising the following steps: (1) Select non-microporous rolled metal foil as the functional layer; (2) A current collection layer is prepared on at least one side surface of the functional layer.
[0027] Preferably, the non-porous rolled metal foil in step (1) is aluminum foil, which also serves as a functional layer and a positive current collector layer.
[0028] Preferably, the non-porous rolled metal foil in step (1) is copper foil, which also serves as the functional layer and the negative electrode current collector.
[0029] Preferably, a protective layer is prepared on the surface of the current collection layer in step (2).
[0030] Preferably, the method for preparing the protective layer includes at least one of physical vapor deposition, chemical vapor deposition, in-situ molding, or coating.
[0031] Thirdly, the present invention provides an electrode sheet containing at least the current collector as described in the first aspect.
[0032] Compared with the prior art, the present invention has the following beneficial effects: This invention employs a non-porous rolled metal foil as the functional layer. Because the grains of the rolled metal are elongated along the rolling direction, forming a flat or fibrous structure, the grain size in the thickness direction is significantly reduced. The grain orientation is preferentially parallel to the molecular diameter (MD), and its tensile properties exhibit anisotropy, resulting in high strength and low elongation in the MD and TD directions. Simultaneously, a current collector layer with fine grains is selectively fabricated on its surface using magnetron sputtering, electroplating, or vapor deposition. The grain orientation in the current collector layer deposited using this method is preferentially perpendicular to the MD and TD, also exhibiting significant anisotropy. The textures of the functional layer and the current collector layer differ significantly in direction. Reducing the grain size of the current collector layer and controlling the grain aspect ratio can shorten the preferential difference in grain orientation between the functional layer and the current collector layer, thereby effectively matching the mechanical properties of the functional layer. By enhancing the matching degree of plastic deformation capacity, it effectively alleviates the delamination and cracking phenomenon between different metal layers, thereby improving the reliability and production yield of the solid-state battery and extending its lifespan. Attached Figure Description
[0033] Figure 1 This is a micrograph of the cross-section of the current collector provided in Example 1. Detailed Implementation
[0034] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.
[0035] One embodiment of the present invention provides a current collector composed of at least two metal layers, including a current collector layer and a functional layer stacked together, wherein the current collector layer includes a positive current collector layer and / or a negative current collector layer.
[0036] The current collector layer is prepared by at least one of magnetron sputtering, electroplating or vapor deposition, and the functional layer is made of non-porous rolled metal foil.
[0037] This invention uses a non-porous rolled metal foil as the functional layer. Because the grains of the rolled metal are elongated along the rolling direction, forming a flat or fibrous structure, the grain size in the thickness direction is significantly reduced, exhibiting obvious grain orientation. Furthermore, its tensile properties are anisotropic, exhibiting high strength and low elongation in the MD and TD directions. Simultaneously, a current collector layer with fine grains is selectively fabricated on its surface using magnetron sputtering, electroplating, or vapor deposition methods, effectively matching the mechanical properties of the functional layer. By enhancing the matching degree of plastic deformation capacity, the delamination and cracking phenomenon between different metal layers is effectively alleviated, thereby improving the reliability and production yield of solid-state batteries and extending the battery's lifespan.
[0038] In some embodiments, the positive current collector layer is attached to the surface of the functional layer, and the negative current collector layer and the functional layer are the same metal layer of the same material, such as copper.
[0039] In some embodiments, the negative current collector layer is attached to the surface of the functional layer, and the positive current collector layer and the functional layer are the same metal layer of the same material, such as aluminum.
[0040] In some embodiments, the grain size of the current collector and the functional layer is independently 0.2-2 μm, for example, it can be 0.2 μm, 0.4 μm, 0.6 μm, 0.8 μm, 1 μm, 1.2 μm, 1.4 μm, 1.6 μm, 1.8 μm or 2 μm, but is not limited to the listed values, other unlisted values within this range are also applicable.
[0041] The present invention limits the grain size of the current collector layer and the functional layer to the range of 0.2-2μm, so that the flat grains of the rolled metal foil and the fine grains of the metal coating match each other, further reducing the difference in interlayer deformation.
[0042] For example, the grain size adjustment methods of the current collector layer and the functional layer include: the functional layer can be adjusted by processes and parameters such as rolling temperature and post-processing; magnetron sputtering can achieve particle size adjustment by adjusting sputtering power, working gas pressure, substrate bias, substrate temperature, substrate layer, periodic interruption of deposition, etc.; evaporation plating can achieve particle size adjustment by adjusting parameters such as deposition rate, substrate temperature, evaporation source temperature, vacuum degree, or by introducing ion beam assisted evaporation technology, distributed deposition + annealing technology, etc.; electroplating can achieve particle size adjustment by processes or parameters such as current density, pulse, chemical additives, electroplating temperature, pH value, stirring or convection.
[0043] In some embodiments, the grain aspect ratio of the current collector is (2-20):1, for example, it can be 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1 or 20:1, but is not limited to the listed values, other unlisted values within this range are also applicable.
[0044] For example, the grain aspect ratio adjustment methods of the current collector layer include: the functional layer can be adjusted by processes and parameters such as rolling temperature and post-processing; magnetron sputtering can achieve particle size adjustment by adjusting sputtering power, working gas pressure, substrate bias, substrate temperature, substrate layer, periodic interruption of deposition, etc.; evaporation plating can achieve particle size adjustment by adjusting parameters such as deposition rate, substrate temperature, evaporation source temperature, vacuum degree, or by introducing ion beam assisted evaporation technology, distributed deposition + annealing technology, etc.; electroplating can achieve particle size adjustment by processes or parameters such as current density, pulse, chemical additives, electroplating temperature, pH value, stirring or convection.
[0045] In some embodiments, the thickness ratio of the current collection layer to the functional layer is 1:(10-50), for example, it can be 1:10, 1:15, 1:20, 1:25, 1:30, 1:35, 1:40, 1:45 or 1:50, but is not limited to the listed values, other unlisted values within this range are also applicable.
[0046] The present invention adopts a structural design of "thin current collector layer + thick functional layer", which balances the conductivity and mechanical strength of the current collector and effectively avoids stress concentration between layers.
[0047] In some embodiments, the material of the functional layer includes at least one of aluminum, copper, or stainless steel, more preferably aluminum and / or copper, and considering conductivity, quality, performance flexibility, and cost, aluminum is even more preferred.
[0048] In some embodiments, the thickness of the functional layer is 10-50 μm, for example, it can be 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm or 50 μm, but is not limited to the listed values, other unlisted values within this range are also applicable.
[0049] In this invention, since the functional layer bears most of the stress and deformation during production and use, and considering its application requirements while taking into account the difficulty and cost of the manufacturing process, the thickness of the functional layer is specifically limited to 10-50 μm.
[0050] In addition, the mechanical properties of the functional layer have the most significant impact on the entire current collector. Pre-treatments such as baking can be performed on it to significantly adjust the overall performance of the current collector. Furthermore, metal foil formed by multiple high-intensity deformation rolling processes can be selected.
[0051] In some embodiments, the positive current collector layer is made of aluminum.
[0052] In some embodiments, the thickness of the positive current collector layer is 0.1-50 μm, for example, it can be 0.1 μm, 1 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm or 50 μm, more preferably 0.1-10 μm, but is not limited to the listed values, other unlisted values within this range are also applicable.
[0053] In some embodiments, the current collector further includes a composite layer, the number of layers of the composite layer is ≥1, the composite layer is disposed on the surface of the functional layer away from the current collector layer, the grain aspect ratio of the composite layer is (5-10):1; the thickness ratio of the current collector layer, the functional layer and the composite layer is 1:(10-20):(2-5).
[0054] In some embodiments, the negative current collector layer is made of copper and / or nickel, more preferably copper.
[0055] In some embodiments, the thickness of the negative electrode current collector is 0.1-50 μm, for example, it can be 0.1 μm, 1 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm or 50 μm, more preferably 0.1-10 μm, but is not limited to the listed values, other unlisted values within this range are also applicable.
[0056] In some embodiments, a protective layer is also provided on the surface of the current collection layer away from the functional layer.
[0057] In some embodiments, the protective layer is made of at least one of nickel, chromium, nickel-based alloys, copper-based alloys, copper oxide, aluminum oxide, silicon oxide, nickel oxide, chromium oxide, cobalt oxide, graphite, carbon black, copper chromate, copper chromite, carbon nanotubes, carbon nanofibers, or graphene.
[0058] In some embodiments, the thickness of the protective layer is 5-100nm, for example, it can be 5nm, 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm or 100nm, more preferably 10-80nm, but is not limited to the listed values, other unlisted values within this range are also applicable.
[0059] In some embodiments, the total thickness of the current collector is 10-100 μm, for example, it can be 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm or 100 μm, but is not limited to the listed values, other unlisted values within this range are also applicable.
[0060] One embodiment of the present invention also provides a method for preparing the current collector described in any of the above embodiments, comprising the following steps: (1) Select non-microporous rolled metal foil as the functional layer; (2) A current collection layer is prepared on at least one side surface of the functional layer.
[0061] In some embodiments, the non-porous rolled metal foil in step (1) is aluminum foil, which also serves as a functional layer and a positive current collector layer.
[0062] In some embodiments, the non-porous rolled metal foil in step (1) is copper foil, which also serves as a functional layer and a negative current collector layer.
[0063] In some embodiments, a protective layer is prepared on the surface of the current collection layer described in step (2).
[0064] In some embodiments, the protective layer is prepared by at least one of physical vapor deposition, chemical vapor deposition, in-situ molding, or coating.
[0065] In this invention, the physical vapor deposition is preferably vacuum evaporation or magnetron sputtering; the chemical vapor deposition is preferably atmospheric pressure chemical vapor deposition or plasma-enhanced chemical vapor deposition; the in-situ forming is preferably forming a metal oxide passivation layer in situ on the surface of the current collector; and the coating is preferably at least one of die coating, blade coating or extrusion coating.
[0066] One embodiment of the present invention also provides an electrode sheet containing at least the current collector described in any of the above embodiments.
[0067] The numerical range described in this invention includes not only the point values listed above, but also any point values within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values included in the range.
[0068] Example 1 This embodiment provides a current collector and its preparation method, specifically including the following steps: (1) 1060H aluminum foil with a thickness of 43μm was selected as the functional layer and positive electrode current collector; (2) Amorphous copper with a thickness of 300 nm was deposited on the surface of aluminum foil by magnetron sputtering; (3) The copper layer is thickened to 1.5 μm by electroplating and used as the negative electrode current collector; (4) A 30 nm thick copper oxide layer was deposited on the surface of the copper layer as a protective layer using an in-situ forming method to obtain the current collector. The cross-sectional micrograph of the current collector is shown in [image missing]. Figure 1 .
[0069] It is estimated that the longitudinal grain size of the aluminum foil in step (1) is about 0.9 μm and the grain aspect ratio is 20:1; the grain size of the copper layer in step (3) is 0.2~1.0 μm and the grain aspect ratio is 1:2.
[0070] Example 2 This embodiment provides a current collector and its preparation method, specifically including the following steps: (1) 1100H aluminum foil with a thickness of 43μm was selected as the functional layer and positive current collector layer; (2) Amorphous copper with a thickness of 300 nm was deposited on the surface of aluminum foil by magnetron sputtering; (3) The copper layer is thickened to 1.5 μm by electroplating and used as the negative electrode current collector; (4) A copper oxide layer with a thickness of 30 nm was deposited on the surface of the copper layer as a protective layer by in-situ forming method to obtain the current collector.
[0071] It is estimated that the longitudinal grain size of the aluminum foil in step (1) is about 1.1 μm and the grain aspect ratio is 10:1; the grain size of the copper layer in step (2) is 0.2~1.0 μm and the grain aspect ratio is 1:2.
[0072] Example 3 This embodiment provides a current collector and its preparation method, specifically including the following steps: (1) 1060H aluminum foil with a thickness of 43μm was selected as the functional layer and positive current collector layer; (2) Amorphous copper with a thickness of 300 nm was deposited on the surface of aluminum foil by magnetron sputtering; (3) The copper layer is thickened to 1.5 μm by electroplating and used as the negative electrode current collector; (4) A copper oxide layer with a thickness of 30 nm was deposited on the surface of the copper layer as a protective layer by in-situ forming method to obtain the current collector.
[0073] It is estimated that the longitudinal grain size of the aluminum foil in step (1) is about 1.3 μm and the grain aspect ratio is 5:1; the grain size of the copper layer in step (3) is 0.2~1.0 μm and the grain aspect ratio is 1:2.
[0074] Example 4 This embodiment provides a current collector and its preparation method, specifically including the following steps: (1) 8021O aluminum foil with a thickness of 13μm was selected as the functional layer and the positive electrode current collector; (2) A copper layer with a thickness of 1.2 μm was deposited on the surface of the aluminum foil by magnetron sputtering as the negative electrode current collector; (3) A copper oxide layer with a thickness of 30 nm was deposited on the surface of the copper layer as a protective layer by in-situ forming method to obtain the current collector.
[0075] It is estimated that the longitudinal grain size of the aluminum foil in step (1) is about 0.9 μm and the grain aspect ratio is 20:1; the grain size of the copper layer in step (2) is 0.2~1.0 μm and the grain aspect ratio is 1:2.
[0076] Example 5 This embodiment provides a current collector and its preparation method, specifically including the following steps: (1) 8021O aluminum foil with a thickness of 40.5 μm was selected as the functional layer and the positive electrode current collector; (2) A copper layer with a thickness of 1.6 μm was deposited on the surface of the aluminum foil by magnetron sputtering as the negative electrode current collector; (3) A copper oxide layer with a thickness of 30 nm was deposited on the surface of the copper layer as a protective layer by in-situ forming method to obtain the current collector.
[0077] It is estimated that the longitudinal grain size of the aluminum foil in step (1) is about 1.6 μm and the grain aspect ratio is 2:1; the grain size of the copper layer in step (2) is 0.4~1.2 μm and the grain aspect ratio is 2:1.
[0078] Example 6 This embodiment provides a current collector and its preparation method. Except for annealing the obtained current collector at 140°C for 30 minutes, the other steps and conditions are the same as in Example 1.
[0079] Example 7 This embodiment provides a current collector and its preparation method, specifically including the following steps: (1) 8021O aluminum foil with a thickness of 18μm was selected as the functional layer and the positive electrode current collector layer; (2) A copper layer with a thickness of 1.6 μm was deposited on the surface of the aluminum foil by magnetron sputtering as the negative electrode current collector; (3) A 6 μm thick aluminum layer was deposited on the surface of the aluminum foil away from the copper layer using magnetron sputtering as a composite layer; (4) A copper oxide layer with a thickness of 30 nm was deposited on the surface of the copper layer as a protective layer by in-situ forming method to obtain the current collector.
[0080] It is estimated that the longitudinal grain size of the aluminum foil in step (1) is about 1.6 μm and the grain aspect ratio is 2:1; the grain size of the copper layer in step (2) is 0.4~1.2 μm and the grain aspect ratio is 2:1; and the grain aspect ratio of the aluminum layer in step (3) is 6:1.
[0081] Comparative Example 1 This comparative example provides a current collector and its preparation method, specifically including the following steps: (1) 1060H aluminum foil with a thickness of 43μm was selected as the functional layer and positive current collector layer; (2) Amorphous copper with a thickness of 300 nm was deposited on the surface of aluminum foil by magnetron sputtering; (3) The copper layer is thickened to 1.5 μm by electroplating and used as the negative electrode current collector; (4) A copper oxide layer with a thickness of 30 nm was deposited on the surface of the copper layer as a protective layer by in-situ forming method to obtain the current collector.
[0082] It is estimated that the longitudinal grain size of the aluminum foil in step (1) is about 2.5 μm and the grain aspect ratio is 1:1; the grain size of the copper layer in step (3) is 0.2~1.0 μm and the grain aspect ratio is 1:2.
[0083] Comparative Example 2 This comparative example provides a current collector and its preparation method, specifically including the following steps: (1) 1060H aluminum foil with a thickness of 43μm was selected as the functional layer and positive current collector layer; (2) Amorphous copper with a thickness of 300 nm was deposited on the surface of aluminum foil by magnetron sputtering; (3) The copper layer is thickened to 1.5 μm by electroplating and used as the negative electrode current collector; (4) A copper oxide layer with a thickness of 30 nm was deposited on the surface of the copper layer as a protective layer by in-situ forming method to obtain the current collector.
[0084] It is estimated that the longitudinal grain size of the aluminum foil in step (1) is about 0.7 μm and the grain aspect ratio is 25:1; the grain size of the copper layer in step (3) is 0.2~1.0 μm and the grain aspect ratio is 1:2.
[0085] Performance testing The current collectors obtained in the above embodiments and comparative examples were cut into 15mm × 15cm strip tensile samples using a foil cutter, ensuring that there were no defects on both sides of the samples as much as possible. The tensile properties of the strip tensile samples were then tested using a tensile testing machine with the following parameters: gauge length 10cm, loading rate 10cm / min, and strain rate 1 / min. The current collectors were tested multiple times in the transverse (TD) and longitudinal (MD) directions. The average of the 10 repeatable results was taken as the final analysis data. The presence of delamination in the metal layer of each sample was observed. Then, the samples from each embodiment were bent 10-20 times until fracture, and the presence of delamination was observed. The relevant test results are shown in Table 1 below.
[0086] Table 1 Therefore, this invention uses non-porous rolled metal foil as the functional layer. Because the grains of the rolled metal are elongated along the rolling direction, forming a flat or fibrous structure, the grain size in the thickness direction is significantly reduced, thus exhibiting high strength and low elongation in the MD and TD directions. At the same time, fine grain current-collecting layers are selectively fabricated on its surface using magnetron sputtering, electroplating, or vapor deposition methods, effectively matching the mechanical properties of the functional layer. By enhancing the matching degree of plastic deformation capacity, the delamination and cracking phenomenon between different metal layers is effectively alleviated, thereby improving the reliability and production yield of solid-state batteries and extending the battery's service life.
[0087] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.
Claims
1. A current collector, characterized in that, The current collector is composed of at least two metal layers, including a current collection layer and a functional layer stacked together, and the current collection layer includes a positive current collection layer and / or a negative current collection layer. The current collector layer is prepared by at least one of magnetron sputtering, electroplating or vapor deposition, and the functional layer is made of non-porous rolled metal foil.
2. The current collector according to claim 1, characterized in that, The positive current collector layer is attached to the surface of the functional layer, and the negative current collector layer and the functional layer are the same metal layer made of the same material; Alternatively, the negative current collector layer is attached to the surface of the functional layer, and the positive current collector layer and the functional layer are the same metal layer made of the same material.
3. The current collector according to claim 1 or 2, characterized in that, The grain size of the current collector layer and the functional layer are each independently 0.2-2 μm; And / or, the grain aspect ratio of the current collector layer is (2-20):1; And / or, the thickness ratio of the current collection layer to the functional layer is 1:(10-50).
4. The current collector according to any one of claims 1-3, characterized in that, The material of the functional layer includes at least one of aluminum, copper or stainless steel, more preferably aluminum and / or copper, and even more preferably aluminum; And / or, the thickness of the functional layer is 10-50 μm.
5. The current collector according to any one of claims 1-3, characterized in that, The positive current collector layer is made of aluminum; And / or, the thickness of the positive current collector layer is 0.1-50 μm, more preferably 0.1-10 μm.
6. The current collector according to any one of claims 1-3, characterized in that, The current collector also includes a composite layer, the number of layers of the composite layer is ≥1, the composite layer is disposed on the surface of the functional layer away from the current collector layer, the grain aspect ratio of the composite layer is (5-10):1; the thickness ratio of the current collector layer, the functional layer and the composite layer is 1:(10-20):(2-5).
7. The current collector according to any one of claims 1-3, characterized in that, The material of the negative electrode current collector includes copper and / or nickel, and is more preferably copper; And / or, the thickness of the negative electrode current collector is 0.1-50 μm, more preferably 0.1-10 μm.
8. The current collector according to any one of claims 1-3, characterized in that, A protective layer is also provided on the surface of the current collection layer away from the functional layer; The protective layer is made of at least one of the following materials: nickel, chromium, nickel-based alloys, copper-based alloys, copper oxide, aluminum oxide, silicon oxide, nickel oxide, chromium oxide, cobalt oxide, graphite, carbon black, copper chromate, copper chromite, carbon nanotubes, carbon nanofibers, or graphene. And / or, the thickness of the protective layer is 5-100 nm, more preferably 10-80 nm; And / or, the total thickness of the current collector is 10-100 μm.
9. A method for preparing a current collector as described in any one of claims 1-8, characterized in that, The preparation method includes the following steps: (1) Select non-microporous rolled metal foil as the functional layer; (2) A current collection layer is prepared on at least one side surface of the functional layer; Among them, the non-porous rolled metal foil in step (1) is aluminum foil, which also serves as a functional layer and a positive current collector layer; Alternatively, the non-porous rolled metal foil in step (1) is copper foil, which also serves as a functional layer and a negative electrode current collector layer; And / or, a protective layer is prepared on the surface of the current collection layer described in step (2); The method for preparing the protective layer includes at least one of physical vapor deposition, chemical vapor deposition, in-situ molding, or coating.
10. An electrode sheet, characterized in that, The electrode contains at least the current collector as described in any one of claims 1-8.