Aluminum-based conductive film and preparation method thereof, current collector, electrode plate and device

Abstract

The invention provides an aluminum-based conductive film and a preparation method thereof, a current collector, an electrode plate and a device. The preparation method of the aluminum-based conductive film comprises the following steps: forming a base layer on a base film; an aluminum film is formed on the base layer through evaporation; wherein the wire feeding speed for evaporation is 300-800 mm / min, and the thickness of an aluminum film obtained through single coating is 0.8-1.5 microns. By controlling the wire feeding speed for evaporation, the metal aluminum film with the thickness of 0.8-1.5 microns can be evaporated at a time.

Description

Aluminum-based conductive film and preparation method thereof, current collector, electrode plate and device Technical Field

[0001] The present application relates to the field of film coating technology, and in particular to an aluminum-based conductive film and a preparation method thereof, a current collector, an electrode plate and a device. Background Art

[0002] Aluminum-based thin film is a composite film formed by coating a layer of metallic aluminum on a base film. The most commonly used processing method is vacuum coating, which involves melting and evaporating the aluminum metal at high temperatures under a high vacuum. The aluminum vapor then precipitates and accumulates on the base film surface, imparting a metallic luster and electrical conductivity. However, the existing vacuum coating process produces a relatively thin film thickness in a single pass. Thicker coatings require multiple evaporation passes.

[0003] Summary of the Invention

[0004] In view of the above technical problems, the present application provides an aluminum-based conductive film and its preparation method, current collector, electrode plate and device, which can achieve a metal aluminum film with a thickness of 0.8-1.5μm by one-time evaporation.

[0005] In the first aspect, the present application provides a method for preparing an aluminum-based conductive film, which includes: providing a base film, on which a base layer is formed; and vapor-depositing an aluminum film on the base layer; wherein the wire feeding speed used for vapor deposition is 300-800 mm / min, and the thickness of the aluminum film obtained by a single coating is 0.8-1.5 μm.

[0006] In the technical solution of the embodiment of the present application, by controlling the wire feeding speed used for evaporation, a metal aluminum film with a thickness of 0.8-1.5μm can be obtained by one evaporation. The thickness of the aluminum film obtained in a single time is relatively thick, which greatly improves the coating efficiency, and the yield of the obtained conductive film is improved. The film layer is more uniform and is less prone to defects such as holes and pinholes.

[0007] In some embodiments, the film speed used for evaporation is 15-30 m / min. By controlling the film speed and coordinating the wire feeding speed, the thickness of the aluminum film obtained by the coating can be controlled, so that a metal aluminum film with a thickness of 0.8-1.5 μm can be obtained in one evaporation.

[0008] In some embodiments, the number of evaporation boats used for evaporation is 24-36. By adjusting the number of evaporation boats, and coordinating the wire feeding speed and film moving speed, the thickness of the aluminum film obtained by the coating can be controlled, so that a metal aluminum film with a thickness of 0.8-1.5 μm can be completed in a single evaporation deposition.

[0009] In some embodiments, the evaporation boat used for evaporation has a power of 7-16 kW, the evaporation temperature is 1600-2000° C., and the cooling roller temperature is -15° C. to 30° C. By adjusting and coordinating the various evaporation parameters, the thickness of the resulting aluminum film can be controlled, allowing a metal aluminum film with a thickness of 0.8-1.5 μm to be deposited in a single evaporation step.

[0010] In some embodiments, the vacuum degree is maintained at 10 -3 -5*10 -3 Pa. It is possible to control the thickness of the aluminum film obtained by the coating, so that a metal aluminum film with a thickness of 0.8-1.5μm can be completed by one evaporation.

[0011] In some embodiments, the diameter of the aluminum wire used for evaporation is 1.8-2.5 mm. By coordinating the wire feeding speed and the film moving speed, the thickness of the aluminum film obtained by the coating can be controlled, so that a metal aluminum film with a thickness of 0.8-1.5 μm can be completed in one evaporation.

[0012] In some embodiments, the method further comprises: online detection of the thickness of the coating using eddy current detection. A closed-loop process method capable of online detection and adjustment of the coating thickness can improve the uniformity of the resulting aluminum film.

[0013] In some embodiments, the base layer is an aluminum nitride layer or an aluminum oxide layer. By using an aluminum nitride or aluminum oxide layer as the base layer, the heat resistance of the base film can be improved, the bonding strength between the base film and the coating can be enhanced, and defects such as holes and pinholes in the aluminum coating can be improved.

[0014] In some embodiments, forming the primer layer on the base film includes vapor-depositing an aluminum nitride layer on the base film; wherein the vapor deposition process utilizes a wire feed speed of 200-500 mm / min and a film feed speed of 200-500 m / min. This method allows for control of the thickness of the resulting aluminum nitride or aluminum oxide layer, resulting in a more uniform primer layer.

[0015] In some embodiments, the power of the evaporation boat used for evaporation is 5-10KW, the evaporation temperature is 1600-2000°C, and the vacuum degree is 10 -3 -5*10 -3 Pa, nitrogen / oxygen flow rate is 2000-9000sccm. By adjusting the various parameters of evaporation and coordinating them, the thickness and uniformity of the base layer can be controlled.

[0016] In some embodiments, the thickness of the primer layer is 5-20 nm. By adjusting the thickness of the primer layer, the bonding strength between the aluminum film and the base film can be enhanced.

[0017] In some embodiments, the method further comprises: chemically oxidizing the aluminum film using ozone to form an oxide protective layer, which can protect the aluminum film from corrosion and extend its service life.

[0018] In some embodiments, the ozone concentration used is 150-300 ppm, the ozone treatment time is 10-30 s, and the ozone treatment temperature is 130-150° C. Under these conditions, ozone can react with aluminum to form a dense oxide film on the surface of the aluminum film.

[0019] In some embodiments, the method further comprises: slitting the aluminum-based conductive film at a slitting speed of 20-70 m / min, so as to slit the film layer into different sizes as required.

[0020] In some embodiments, the base film includes one or more of a polyethylene terephthalate film, a polypropylene film, and a polyethylene film, and the thickness of the base film is 6-13 μm.

[0021] In some embodiments, the aluminum-based conductive film has a surface thickness resistance of 23-40 mΩ.

[0022] In a second aspect, the present application provides an aluminum-based conductive film, which is prepared using any of the above-mentioned methods for preparing aluminum-based conductive films. The obtained aluminum-based conductive film has a thickness of 0.8-1.5 μm, a more uniform thickness, and fewer defects such as pinholes and holes.

[0023] In some embodiments, the aluminum-based conductive film includes a base film, a primer layer, and an aluminum film that are stacked, and the primer layer is an aluminum nitride layer or an aluminum oxide layer.

[0024] In some embodiments, the aluminum-based conductive film includes a base film, a primer layer, an aluminum film, and an oxide protection layer that are stacked.

[0025] In a third aspect, the present application provides a current collector, which includes any of the aluminum-based conductive films described above.

[0026] Since the current collector of the present application includes the aluminum-based conductive film provided by the present application, it has at least the same advantages as the aluminum-based conductive film.

[0027] In a fourth aspect, the present application provides an electrode plate, which includes any of the above-mentioned current collectors.

[0028] Since the electrode of the present application includes the current collector provided by the present application, it has at least the same advantages as the current collector.

[0029] In a fifth aspect, the present application provides a battery, comprising the electrode plate of any one of the above items.

[0030] Since the battery of the present application includes the electrode provided by the present application, it has at least the same advantages as the electrode.

[0031] In a sixth aspect, the present application provides an electrical device, which includes the battery of any one of the above items.

[0032] Since the electric device of the present application includes the battery provided by the present application, it has at least the same advantages as the battery.

[0033] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0035] FIG1 is a schematic structural diagram of a vehicle according to some embodiments of the present application;

[0036] FIG2 is a schematic diagram of the exploded structure of a battery according to some embodiments of the present application;

[0037] FIG3 is a schematic diagram of the exploded structure of a battery cell according to some embodiments of the present application;

[0038] FIG4 is a schematic structural diagram of an aluminum-based conductive film preparation device according to some embodiments of the present application;

[0039] FIG5 is a schematic flow chart of a method for preparing an aluminum-based conductive film according to some embodiments of the present application;

[0040] FIG6 is a schematic structural diagram of an aluminum-based conductive film according to some embodiments of the present application;

[0041] FIG7 is a schematic SEM structural diagram of an aluminum-based conductive film according to some embodiments of the present application;

[0042] FIG8 is a schematic diagram of the SEM structure of the aluminum-based conductive film according to some embodiments of the present application. DETAILED DESCRIPTION

[0043] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0045] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0046] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0047] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0048] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0049] Batteries, as a new generation of green energy storage and conversion devices, have been widely used in fields such as portable electronic devices and electric vehicles. Batteries consist of a positive electrode, a negative electrode, a separator, and an electrolyte. The positive and negative electrodes contain active materials and a current collector, which can be selected from aluminum, copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a polymer substrate coated with a conductive metal, and combinations thereof.

[0050] Among them, when a polymer composite film coated with an aluminum film is selected as a current collector, the polymer composite film includes a base film and an aluminum film. The vacuum coating technology is usually used to evaporate the aluminum film on the base film to obtain a composite film. Since the base film is not conductive, the aluminum film needs to reach a certain thickness (such as 1μm) to meet the electrical requirements of the battery current collector. However, the thickness of the aluminum coating obtained by a single evaporation in the existing evaporation process is only 20-50nm, and it takes 20 times to evaporate a 1μm aluminum coating, which is a huge bottleneck for product yield and production efficiency. In particular, the base film is generally thin and has poor heat resistance. Multiple evaporation will cause defects such as deformation, wrinkles, and holes on the base film surface. At the same time, due to the thin thickness of the film, the tension control adjustment space is limited, which can easily lead to defects such as film breakage, making the material scrapped.

[0051] Based on this, this application provides a method for preparing an aluminum-based conductive film. The resulting aluminum-based conductive film can be used as a current collector for electrodes. By controlling the wire feed speed used in evaporation, the preparation method provided by this application can achieve an aluminum film thickness of 0.8-1.5 μm obtained through a single coating. The resulting coating quality, uniformity, and resistance meet the requirements for lithium battery current collectors, significantly improving their safety and ultimate energy density.

[0052] The aluminum-based conductive film preparation method provided in this application is applicable to the field of preparing current collectors used in new energy batteries, and is also applicable to other coating industries.

[0053] The battery disclosed in the embodiments of the present application can be used in electrical devices that use the battery as a power source or various energy storage systems that use the battery as an energy storage element. The electrical device can be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, and the like. Among them, the electric toy can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and the like, and the spacecraft can include airplanes, rockets, space shuttles, and spacecraft, and the like.

[0054] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application.

[0055] Please refer to Figure 1, which is a schematic structural diagram of a vehicle 1000 provided in some embodiments of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 can be provided at the bottom, head or tail of the vehicle 1000. The battery 100 can be used to power the vehicle 1000. For example, the battery 100 can serve as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0056] In some embodiments of the present application, the battery 100 can serve not only as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0057] Please refer to Figure 2, which is a schematic diagram of the exploded structure of a battery 100 provided in some embodiments of the present application. The battery 100 includes a housing 10 and battery cells 20, with the battery cells 20 housed within the housing 10. The housing 10 provides a storage space for the battery cells 20 and can have various structures. In some embodiments, the housing 10 can include a first portion 11 and a second portion 12, which overlap each other and together define a storage space for the battery cells 20. The second portion 12 can be a hollow structure with one end open. The first portion 11 can be a plate-like structure, with the first portion 11 overlapping the open side of the second portion 12, so that the first portion 11 and the second portion 12 together define a storage space. Alternatively, the first portion 11 and the second portion 12 can each be a hollow structure with one end open, with the open side of the first portion 11 overlapping the open side of the second portion 12. Of course, the housing 10 formed by the first portion 11 and the second portion 12 can have various shapes, such as a cylinder or a rectangular parallelepiped.

[0058] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 20. The multiple battery cells 20 may be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery cell 20 may be housed within the housing 10. Alternatively, the battery 100 may be constructed by first connecting multiple battery cells 20 in series, in parallel, or in a hybrid connection to form a battery module, which is then connected in series, in parallel, or in a hybrid connection to form a complete battery module, and then housed within the housing 10. The battery 100 may also include other structures, such as a busbar assembly for electrically connecting the multiple battery cells 20.

[0059] Each battery cell 20 may be a secondary battery or a primary battery, and may also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 20 may be cylindrical, flat, rectangular, or in other shapes.

[0060] Please refer to Figure 3, which is a schematic diagram of the exploded structure of a battery cell 20 provided in some embodiments of the present application. A battery cell 20 is the smallest unit that makes up a battery. As shown in Figure 3, a battery cell 20 includes an end cap 21, a housing 22, an electrode assembly 23, and other functional components.

[0061] The end cap 21 is a component that covers the opening of the housing 22 to isolate the internal environment of the battery cell 20 from the external environment. The shape of the end cap 21 can be adapted to the shape of the housing 22 to fit the housing 22. Optionally, the end cap 21 can be made of a material with a certain hardness and strength (such as an aluminum alloy). This prevents the end cap 21 from deforming when subjected to compression or collision, thereby providing the battery cell 20 with greater structural strength and improved safety. The end cap 21 can be provided with functional components such as electrode terminals 21a. The electrode terminals 21a can be used to electrically connect to the electrode assembly 23 for inputting or outputting electrical energy from the battery cell 20. In some embodiments, the end cap 21 can also be provided with a pressure relief mechanism for relieving internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold. The end cap 21 can also be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this embodiment of the present application does not impose any particular limitations on this. In some embodiments, an insulating member may be provided inside the end cap 21 to isolate the electrical connection components in the housing 22 from the end cap 21 to reduce the risk of short circuit. For example, the insulating member may be made of plastic, rubber, or the like.

[0062] The housing 22 is a component that cooperates with the end cap 21 to form the internal environment of the battery cell 20. This internal environment can be used to accommodate the electrode assembly 23, electrolyte, and other components. The housing 22 and end cap 21 can be separate components. An opening can be provided in the housing 22, and the end cap 21 is placed over the opening to form the internal environment of the battery cell 20. Alternatively, the end cap 21 and housing 22 can be integrated. Specifically, the end cap 21 and housing 22 can form a common connection surface before other components are inserted into the housing. When the interior of the housing 22 needs to be enclosed, the end cap 21 is placed over the housing 22. The housing 22 can have a variety of shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, or a hexagonal prism. Specifically, the shape of the housing 22 can be determined based on the specific shape and size of the electrode assembly 23. The housing 22 can be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this embodiment of the present application does not impose any particular limitations on this.

[0063] The electrode assembly 23 is a component in the battery cell 100 where electrochemical reactions occur. One or more electrode assemblies 23 may be contained in the housing 22. The electrode assembly 23 is mainly formed by winding or stacking positive and negative electrode sheets, and a separator is usually provided between the positive and negative electrode sheets. The parts of the positive and negative electrode sheets with active materials constitute the main body of the electrode assembly, and the parts of the positive and negative electrode sheets without active materials each constitute a tab 23a. The positive and negative electrode tabs may be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery, the positive active material and the negative active material react with the electrolyte, and the tabs 23a connect the electrode terminals to form a current loop.

[0064] According to some embodiments of the present application, a method for preparing an aluminum-based conductive film is provided, the method comprising: providing a base film, with a base layer formed on the base film; forming an aluminum film by vapor deposition on the base layer; the wire feeding speed used for vapor deposition is 300-800 mm / min, and the thickness of the aluminum film obtained by a single coating is 0.8-1.5 μm.

[0065] Among them, the vacuum coating technology can be used to evaporate and form an aluminum film on the base layer.

[0066] Please refer to Figure 4, which is a schematic diagram of the structure of the aluminum-based conductive film preparation equipment of some embodiments of the present application. Specifically, the coating equipment includes ① a winding mechanism; ② a correction roller; ③ a flattening roller; ④ a main evaporation roller; ⑤ a flattening roller; ⑥ a pass roller; ⑦ an eddy current sensor; ⑧ a flattening roller; ⑨ a pass roller; ⑩ a flattening roller; Evaporation main roller; Flattening rollers; Roller; ion source; ion source; Roller; Unwinding mechanism; Evaporation source adjustment mechanism; Evaporation mechanism.

[0067] Specifically, the base film with the base layer is placed in the vacuum coating equipment, vacuumed, and preheated after reaching a predetermined vacuum degree. Then, the aluminum wire transmission is started, and the wire feeding speed is controlled between 300-800mm / min. The equipment is started to wind, and the equipment baffle is opened to start evaporation. The aluminum vapor condenses onto the base layer to form an aluminum film.

[0068] In this embodiment, by controlling the wire feed speed between 300-800 mm / min, a single vapor deposition process can achieve a 0.8-1.5 μm thick aluminum film. The thick aluminum film obtained in a single deposition process greatly improves the coating efficiency and the yield of the resulting conductive film. The film layer is more uniform and less prone to defects such as holes and pinholes. The wire feed speed can be 350-750 mm / min, 400-600 mm / min, 300-500 mm / min, 450-700 mm / min, 500-800 mm / min, etc.

[0069] In one embodiment, the method for preparing an aluminum-based conductive film provided herein further includes controlling the film feed speed to be between 15-30 m / min. In this way, the thickness of the aluminum film is regulated in conjunction with the wire feed speed, so that the thickness of the aluminum film obtained in a single pass is relatively thick and the film layer is more uniform. The film feed speed can be 15-30 m / min, 18-27 m / min, 21-26 m / min, 17-20 m / min, 25-30 m / min, 15-00 m / min, etc.

[0070] In one embodiment, the method for preparing an aluminum-based conductive film provided herein further comprises: using 24-36 evaporation boats for evaporation, with a power of 7-16 kW, a evaporation temperature of 1600-2000°C, and a cooling roller temperature of -15°C to 30°C. By adjusting and coordinating these process parameters, the resulting aluminum film can be made uniform and thicker.

[0071] The number of evaporation boats can be adjusted according to the wire feeding speed. If the wire feeding speed is fast, more evaporation boats can be used as much as possible, such as evaporation boats on only one side or both sides. The number can be 24, 28, 30, etc.

[0072] In one embodiment, the aluminum wire used in the method for preparing an aluminum-based conductive film provided herein has a diameter of 1.8-2.5 mm. By coordinating the wire feeding speed and the film moving speed, the thickness of the resulting aluminum film can be controlled, enabling a single vapor deposition process to produce a metal aluminum film with a thickness of 0.8-1.5 μm.

[0073] In one embodiment, the vacuum degree is controlled to be 10 -3 -5*10 -3 By controlling the vacuum degree, the film forming speed and thickness can be controlled, which is more conducive to film deposition and makes the film formation more uniform.

[0074] In one embodiment, the method for preparing an aluminum-based conductive film provided herein further includes: utilizing eddy current testing to detect the coating thickness online, thereby achieving closed-loop thickness adjustment of the coating to achieve a more uniform coating. In other words, the coating thickness can be detected and adjusted online.

[0075] In one embodiment, the properties of the underlying layer on the base film also affect the formation of the aluminum film. The method for preparing an aluminum-based conductive film provided herein uses aluminum nitride as the underlying layer, which can improve the underlying layer's heat resistance. Aluminum nitride has a better thermal conductivity, allowing for timely heat transfer and improving the underlying layer's heat resistance. In other embodiments, aluminum oxide can also be used as the underlying layer.

[0076] In one embodiment, the thickness of the primer layer is 5-20 nm. In this way, the adhesion between the coating layer and the base film can be improved, making the film layer more uniform, and at the same time, defects such as holes and pinholes in the coating aluminum film can be improved.

[0077] In one embodiment, an aluminum nitride layer can be formed by vapor deposition on a base film. The wire feeding speed used for vapor deposition is 200-500 mm / min, the film feeding speed is 200-500 m / min, the power of the evaporation boat is 5-10 KW, the vapor deposition temperature is 1600-2000 ° C, and the vacuum degree is 10 -3 -5*10 -3 Pa, nitrogen (when the base layer is alumina, the gas is replaced by oxygen) flow rate is 2000-9000sccm. By properly adjusting various process parameters, the thickness and uniformity of the base layer can be controlled.

[0078] In one embodiment, after the aluminum film is formed, it can be oxidized to form a protective oxide layer on its surface, protecting it from corrosion. In particular, when applied to an electrode current collector, this layer can prevent corrosion of the metal layer of the current collector by the lithium battery electrolyte, thereby extending the cycle life of the current collector.

[0079] In one embodiment, the ozone concentration used for oxidation is 150-300 ppm, the ozone treatment time is 10-30 seconds, and the ozone treatment temperature is 130-150° C. Specifically, ozone can oxidize aluminum at a temperature of 140° C., forming a dense oxide film on the surface of the aluminum film.

[0080] Please refer to FIG5 , which is a schematic flow chart of a method for preparing an aluminum-based conductive film according to some embodiments of the present application. In this embodiment, the method for preparing an aluminum-based conductive film includes:

[0081] Provide a base film. The base film may include one or more of polyethylene terephthalate (PET) film, polypropylene (PP) film, and polyethylene (PE) film. The base film has a thickness of 6-13 μm. The base film material may be inspected for compliance with standards for length, width, appearance, thickness, elongation, dyne value, quality, and light transmittance. The base film may be pretreated. Taking PET base film as an example, the PET film may be dried at a constant temperature for 2-4 hours to remove moisture and strengthen the bonding between the base film and the coating.

[0082] Provide vacuum coating equipment. Check the size and appearance of the evaporation boat, then conduct equipment inspection and start-up inspection.

[0083] Open the vacuum box, place the base film on the unwinding shaft, fix it on the film threading belt, and automatically thread the film to enter the production preparation state.

[0084] Vacuum to high vacuum level (vacuum degree at 10 -3 -5*10 -3 Pa), open the evaporation boat and preheat it to 70% to 85% of the evaporation temperature (equipment setting, can be adapted to change), and feed aluminum wire into the evaporation boat. The diameter of the aluminum wire used is 1.8 to 2.5 mm. Detect the wire diameter and purity of the aluminum wire material before use. Adjust the wire feeding speed to 200-500 mm / min, the film feeding speed to 200-500 m / min, and introduce nitrogen (can also be replaced by oxygen); adjust the power of the evaporation boat to 5-10KW, the evaporation temperature to 1600-2000 ° C, the oxygen or nitrogen flow rate to 2000-9000 sccm, start the film feeding process, and use the eddy current detection method to detect the coating thickness online. After the thickness of the aluminum nitride film layer is 5-20nm, turn off the equipment, take out the film material and send it to the next step. Through the production of the aluminum nitride film layer, the adhesion between the coated aluminum film and the base film is improved. The base layer is made of aluminum nitride, which can quickly cool the base film attached to the cold roller to obtain a dense base layer.

[0085] Clean the vacuum evaporation equipment, then install the base film with the primer layer into the vacuum evaporation equipment, open the evaporation boat for preheating, and when the evaporation boat power reaches 2500W, feed aluminum wire into the evaporation boat, and adjust the wire feeding speed to 300-800mm / min, the film feeding speed to 15-30m / min, the evaporation boat power to 7-16KW, the evaporation temperature to 1600-2000℃, the cooling roller temperature to -15℃~30℃, and the vacuum degree to 10 -3 -5*10 -3Pa. The film-forming process begins. Eddy current testing is also used to measure the coating thickness online. When the aluminum film thickness reaches 0.8-1.5 μm, the equipment is shut down, the film is removed, and sent to the next process.

[0086] The composite film with aluminum film is placed in an ozone atmosphere for chemical oxidation. The ozone concentration is 150-300ppm, the ozone treatment time is 10-30s, and the ozone treatment temperature is 130-150°C. Under these conditions, ozone can react with aluminum to form a dense oxide film on the surface of the aluminum film.

[0087] The finished film material is collected into a roll. When winding, as the coating thickens, the physical properties of the film change. It is necessary to properly adjust the tension and the bending roller angle to flatten the film surface to avoid wrinkles on the film surface. The resulting film material structure is shown in Figures 6-8. Figure 6 is a schematic diagram of the structure of the aluminum-based conductive film in some embodiments of the present application. Figure 7 is a schematic diagram of the SEM structure of the aluminum-based conductive film in some embodiments of the present application. Figure 8 is a schematic diagram of the SEM structure of the aluminum-based conductive film in some embodiments of the present application. The thickness of the obtained aluminum-based conductive film is 0.8-1.5μm, the thickness is more uniform, and there are fewer defects such as pinholes and holes.

[0088] Slitting and forming. The obtained film material is cut according to the use requirements at a cutting speed of 20-70m / min. The cut roll material is labeled.

[0089] In the above embodiments, the method provided by this application can achieve a single-step evaporation deposition of a 0.8-1.5μm thick aluminum film. Furthermore, the coating thickness can be monitored and adjusted online. The resulting coating also has a dense oxide protective layer on the surface, and the surface resistance of the aluminum-based conductive film is 23-40mΩ.

[0090] The aluminum-based conductive film obtained in the above embodiment can be applied to electrode current collectors. The coating quality uniformity and resistance of the film layer can meet the requirements of lithium battery current collectors, greatly improving their safety and ultimate energy density.

[0091] According to some embodiments of the present application, the present application also provides an electrode plate, which includes any of the above-mentioned current collectors.

[0092] According to some embodiments of the present application, the present application further provides a battery, the battery comprising any of the electrode plates described above. The battery structure can be any of the above methods.

[0093] According to some embodiments of the present application, the present application further provides an electrical device, which includes a battery according to any of the above solutions, and the battery is used to provide electrical energy to the electrical device.

[0094] The power-consuming device may be any of the aforementioned devices or systems using batteries.

[0095] In the above embodiment, a single vapor deposition process can produce a 0.8-1.5μm thick aluminum film. The coating thickness can be monitored and adjusted online. The resulting coating also features a dense oxide protective layer, resulting in a surface resistivity of 23-40mΩ. The resulting aluminum-based conductive film's coating quality, uniformity, and resistance meet the requirements for lithium battery current collectors, significantly improving safety and ultimate energy density.

[0096] The scheme of the present application is described below with reference to specific embodiments. Those skilled in the art will understand that the aluminum-based conductive film and preparation method described in the present application are merely examples, and any other suitable preparation method is within the scope of the present application.

[0097] Specifically, according to the above-described steps, a base film was provided, a primer layer was formed on the base film by vapor deposition, and an aluminum film was formed on the primer layer by vapor deposition. Specific process parameters are detailed in Table 1. The resulting aluminum-based conductive film was then subjected to performance testing using standard testing methods conventional in the art, as detailed in Table 2.

[0098]

[0099] Table 2: Performance parameters of the films obtained in various examples and comparative examples

[0100]

[0101] The above data demonstrates that the aluminum film thickness achieved by a single coating process using the present invention can reach 0.8-1.5 μm. Furthermore, the resulting coating quality, uniformity, and resistance meet the requirements for lithium battery current collectors, significantly improving their safety and ultimate energy density. The film is more uniform and less susceptible to defects such as holes and pinholes.

[0102] The above description is only an implementation method of the present application and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the description and drawings of this application, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for preparing an aluminum-based conductive film, wherein: The method comprises: Providing a base film, on which a primer layer is formed; Forming an aluminum film by evaporating on the base layer; The wire feeding speed used for evaporation is 300-800 mm / min, and the thickness of the aluminum film obtained by a single coating is 0.8-1.5 μm.

2. The method for preparing an aluminum-based conductive film according to claim 1, wherein: The film travel speed used for evaporation is 15-30m / min.

3. The method for preparing an aluminum-based conductive film according to claim 1 or 2, wherein: The number of evaporation boats used for evaporation is 24-36.

4. The method for preparing an aluminum-based conductive film according to claim 3, wherein: The power of the evaporation boat used for evaporation is 7-16KW, the evaporation temperature is 1600-2000℃, and the temperature of the cooling roller is -15℃~30℃.

5. The method for preparing an aluminum-based conductive film according to any one of claims 1 to 4, wherein: The vacuum degree is maintained at 10 -3 -5*10 -3 Pa.

6. The method for preparing an aluminum-based conductive film according to any one of claims 1 to 5, wherein: The diameter of the aluminum wire used for evaporation is 1.8-2.5mm.

7. The method for preparing an aluminum-based conductive film according to any one of claims 1 to 6, wherein: The method further comprises: using an eddy current detection method to detect the thickness of the coating online.

8. The method for preparing an aluminum-based conductive film according to any one of claims 1 to 7, wherein: The bottom layer is an aluminum nitride layer or an aluminum oxide layer.

9. The method for preparing an aluminum-based conductive film according to claim 8, wherein: The base film is provided with a primer layer, which comprises: Vapor-depositing an aluminum nitride layer or an aluminum oxide layer on the base film; Among them, the wire feeding speed used for evaporation is 200-500mm / min, and the film feeding speed is 200-500m / min.

10. The method for preparing an aluminum-based conductive film according to claim 9, wherein: The step of evaporating and forming an aluminum nitride film on the base film comprises: The power of the evaporation boat used for evaporation is 5-10KW, the evaporation temperature is 1600-2000℃, and the vacuum degree is 10 -3 -5*10 -3 Pa, nitrogen / oxygen flow rate is 2000-9000sccm.

11. The method for preparing an aluminum-based conductive film according to any one of claims 1 to 10, wherein: The thickness of the primer layer is 5-20 nm.

12. The method for preparing an aluminum-based conductive film according to any one of claims 1 to 11, wherein: After the aluminum film is formed by evaporation on the base layer, the method further comprises: The aluminum film is chemically oxidized by using ozone to form an oxide protective layer.

13. The method for preparing an aluminum-based conductive film according to claim 12, wherein: The chemical oxidation treatment of the aluminum film by using ozone to form an oxide protective layer comprises: The ozone concentration is 150-300ppm, the ozone treatment time is 10-30s, and the ozone treatment temperature is 130-150°C.

14. The method for preparing an aluminum-based conductive film according to any one of claims 1 to 13, wherein: After the aluminum film is formed by evaporation on the base layer, the method further comprises: The aluminum-based conductive film is cut at a speed of 20-70 m / min.

15. The method for preparing an aluminum-based conductive film according to any one of claims 1 to 14, wherein: The base film includes one or more of a polyethylene terephthalate film, a polypropylene film, and a polyethylene film, and the thickness of the base film is 6-13 μm.

16. The method for preparing an aluminum-based conductive film according to any one of claims 1 to 15, wherein: The surface thickness of the aluminum-based conductive film has a square resistance of 23-40 mΩ.

17. An aluminum-based conductive film, wherein: The method for preparing an aluminum-based conductive film is used as described in any one of claims 1 to 15.

18. The aluminum-based conductive film according to claim 17, wherein: The aluminum-based conductive film includes a base film, a primer layer and an aluminum film which are stacked, and the primer layer is an aluminum nitride layer or an aluminum oxide layer.

19. The aluminum-based conductive film according to claim 17 or 18, wherein: The aluminum-based conductive film includes a base film, a primer layer, an aluminum film and an oxide protection layer which are stacked.

20. A current collector, wherein: Comprising the aluminum-based conductive film as described in claim 19.

21. An electrode plate, wherein: Comprising the current collector as claimed in claim 20.

22. A battery, wherein: Comprising the electrode plate as described in claim 21.

23. An electrical device, wherein: Comprising a battery as claimed in claim 22.

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