Multilayer pole piece, preparation method thereof and battery

Abstract

The invention belongs to the technical field of batteries, provides a multi-layer pole piece and a preparation method thereof, and further provides a battery. The multi-layer pole piece comprises a base body, and the material of the base body comprises at least one of copper, aluminum, stainless steel, polypropylene, polyimide, polyethylene and polyethylene glycol terephthalate; at least one functional layer attached to the surface of the substrate through magnetron sputtering, wherein the functional layer at least comprises a negative active material layer; optionally, the functional layer further comprises a current collector layer located between the active material layer and the substrate. The functional negative active material is compounded on the surface of the current collector substrate through magnetron sputtering, so that the integration of the negative current collector and the negative active material layer is realized, the negative current collector can be directly used as a negative pole piece, the thickness of the pole piece is reduced, and the energy density of the battery is improved.

Description

Technical Field

[0001] This invention belongs to the field of battery technology, specifically relating to a multilayer electrode and its preparation method, and also provides a battery. Background Technology

[0002] Current negative electrode current collectors are made of copper foil or copper foil composited with polymers. Copper foil is synthesized through electrolysis, magnetron sputtering, vacuum evaporation, or other methods. Polymer composite copper foil uses polymer materials such as PET (polyethylene terephthalate) / PP (polypropylene) as the intermediate layer base film, and forms a double copper conductive layer by depositing it on both sides of the base film through processes such as vacuum deposition. Then, a negative electrode sheet is formed by coating the negative electrode active material onto the negative electrode current collector. Batteries made from this negative electrode sheet have relatively low energy density. Summary of the Invention

[0003] The present invention aims to at least partially solve the aforementioned technical problems. Therefore, one objective of the present invention is to propose a multilayer electrode and its efficient preparation method, as well as a battery in which functional materials (including negative electrode active materials) are composited onto the substrate surface of a current collector via magnetron sputtering, achieving integration of the current collector and the active material layer. This allows for direct use as an electrode, reducing electrode thickness and increasing battery energy density.

[0004] The first aspect of this application provides a multilayer electrode. According to an embodiment of the present invention, the multilayer electrode includes: a substrate, the material of which includes at least one selected from copper, aluminum, stainless steel, polypropylene, polyimide, polyethylene, and polyethylene terephthalate; at least one functional layer attached to the surface of the substrate by magnetron sputtering, the functional layer including at least a negative electrode active material layer; optionally, the functional layer further includes a current collector layer located between the active material layer and the substrate.

[0005] The multilayer electrode provided in this application embodiment allows for the direct magnetron sputtering attachment of an active material layer onto the surface of the current collector substrate. This means that a functional layer with charge / discharge active material is used to modify the current collector substrate, forming an integrated structure that combines the functions of the current collector and the active material. This multilayer electrode can de-intercalate and re-intercalate Li. + / Na +These can be used as positive / negative electrode sheets for batteries. For example, copper surface-modified with a lithium metal layer can be used as the negative electrode sheet for lithium metal batteries. The multilayer electrode sheet provided in this application embodiment can use a thicker substrate layer, and the active material layer is attached to the substrate surface by magnetron sputtering, forming a layer with a thickness much smaller than that of the active material slurry coating layer. Compared with the traditional process of using lithium metal rolling, this application embodiment can form a thinner metal layer, thereby helping to reduce the overall volume and weight of the electrode sheet and improve the energy density of the battery. At the same time, the active material layer is attached to the substrate surface by magnetron sputtering, which increases the bonding strength between the two and the bonding interface stability. The active material layer has fewer surface defects and controllable edges, and the interface stability of the active material layer is high, which is conducive to the formation of a stable SEI film, reducing volume expansion, and improving the energy density of the battery.

[0006] In addition, a current collector layer and an active material layer can be magnetron sputtered onto the surface of a polymer material (such as at least one of polypropylene, polyimide, polyethylene, and polyethylene terephthalate) to form an integrated structure that combines the functions of current collector and active material.

[0007] According to embodiments of the present invention, the above-mentioned multilayer electrode sheet may further include at least one of the following additional technical features:

[0008] In some embodiments, the material of the current collector layer includes at least one of copper and aluminum; and / or, the active material includes at least one of metallic and non-metallic materials.

[0009] In some embodiments, the metallic material includes at least one of lithium, aluminum, tin, and sodium; and / or, the non-metallic material includes at least one of silicon and carbon.

[0010] In some embodiments, the thickness of the substrate is 2 μm to 20 μm; and / or, the thickness of the functional layer is 0.5 μm to 50 μm.

[0011] In some embodiments, the multilayer electrode includes at least one of Cu-Li multilayer electrode, Cu-Al multilayer electrode, Cu-Sn multilayer electrode, Al-Na multilayer electrode, Cu-Si multilayer electrode, Cu-C multilayer electrode, SUS-C multilayer electrode, Al-C multilayer electrode, Cu-Li-C multilayer electrode, Cu-Al-C multilayer electrode, PP-Cu-Li multilayer electrode, and PI-Cu-Li multilayer electrode.

[0012] In some embodiments, the multilayer electrode is at least one of Al-Na multilayer electrode, Al-C multilayer electrode, Cu-Li-C multilayer electrode, Cu-Al-C multilayer electrode, and PP-Cu-Li multilayer electrode.

[0013] The second aspect of this application provides a method for preparing a multilayer electrode, wherein at least one coating layer is sputtered as a functional layer on the surface of a substrate using a vacuum magnetron sputtering method to prepare the aforementioned multilayer electrode.

[0014] This application employs magnetron sputtering to prepare multilayer electrodes. An active material layer is directly formed on the surface of the current collector via magnetron sputtering, creating an integrated structure that combines the functions of the current collector and the active material, suitable for use as a battery electrode. The use of magnetron sputtering in this application's embodiments facilitates the preparation of thin functional layers, especially the active material layer, reducing the overall volume and weight of the electrode and increasing the battery's energy density. Simultaneously, the active material layer adheres to the substrate surface via magnetron sputtering, increasing the bonding strength and interfacial stability. The active material layer exhibits fewer surface defects, and the negative electrode active material layer demonstrates higher interfacial stability, which is beneficial for forming a stable SEI film, reducing volume expansion, and further improving the battery's energy density.

[0015] In some implementations, the control parameters in vacuum magnetron sputtering include any one of the following (1) to (3):

[0016] (1) Voltage: 1000V~5000V;

[0017] (2) Vacuum degree: 4×10 -3 Below Pa;

[0018] (3) The magnetic control speed is 5m / min to 8m / min.

[0019] In some implementations, the control parameters in vacuum magnetron sputtering include any one of the following (1) to (3):

[0020] (1) Voltage: 1200V~1400V;

[0021] (2) Vacuum degree: 3×10 -3 Pa~4×10 -3 Pa;

[0022] (3) The magnetic control speed is 6m / min to 7m / min.

[0023] A third aspect of this application provides a battery comprising the multilayer electrode sheet described above, or a multilayer electrode sheet obtained by the preparation method described above.

[0024] The battery provided in this application includes the aforementioned multilayer electrode sheets, exhibits good electrochemical performance, and has a high energy density.

[0025] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0026] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0027] Figure 1 This is a process flow diagram of a method for preparing multilayer electrodes according to an embodiment of this application.

[0028] Figure 2 This is a schematic diagram of the double-layer electrode structure of magnetron sputtering according to an embodiment of this application.

[0029] Figure 3 This is a schematic diagram of the three-layer electrode structure of magnetron sputtering according to an embodiment of this application.

[0030] Figure 4 This is a schematic diagram of the electrode structure for magnetron sputtering of a specific pattern according to an embodiment of this application. Detailed Implementation

[0031] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0032] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0033] In this document, the terms “comprising” or “including” are open-ended expressions, meaning they include the contents specified in this invention but do not exclude other aspects.

[0034] The present invention will be explained below with reference to embodiments. Those skilled in the art will understand that the following embodiments are for illustrative purposes only and should not be considered as limiting the scope of the invention. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in the field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0035] The first aspect of this application provides a multilayer electrode sheet, comprising:

[0036] The matrix material includes at least one of copper, aluminum, stainless steel, polypropylene, polyimide, polyethylene, and polyethylene terephthalate.

[0037] At least one functional layer is attached to the surface of a substrate by magnetron sputtering, the functional layer including at least a negative electrode active material layer; optionally, the functional layer also includes a current collector layer located between the active material layer and the substrate.

[0038] In existing technologies, the negative electrode electrode is typically prepared by coating a slurry of negative electrode active material onto the surface of copper foil or polymer composite copper foil, followed by drying and solvent removal. On one hand, for polymer composite copper foil, to improve energy density, the metal layer thickness needs to be reduced. However, due to process limitations, the thinner the composite copper foil metal layer, the more surface defects (pores, impurities) there are. After bonding with the negative electrode active material layer, the defects on the current collector surface affect the adhesion between it and the negative electrode active material, causing the active material to detach during charging and discharging, thus reducing the battery's energy density. On the other hand, the negative electrode active material layer is usually prepared using a slurry process, resulting in a relatively thick layer and consequently, a relatively low battery energy density. Furthermore, commonly used current collectors, such as copper foil or polymer composite copper foil, only function as current collectors and cannot achieve lithium-ion intercalation / deintercalation, thus having a single function.

[0039] The multilayer electrode provided in this application involves directly magnetron sputtering an active material layer onto the surface of a current collector (such as at least one of copper, aluminum, and stainless steel). This means the current collector is modified with a functional layer containing charge-discharge active material, forming an integrated structure that combines the functions of the current collector and the active material. This multilayer electrode can de-intercalate and re-intercalate Li. + / Na + It can be used as a negative electrode in batteries. For example, copper with a lithium metal layer on its surface can be used as a negative electrode in lithium metal batteries.

[0040] The multilayer electrode provided in this application embodiment can employ a relatively thick substrate layer, with the active material layer attached to the substrate surface via magnetron sputtering. This results in a thickness much smaller than that of the negative electrode active material slurry coating layer. Compared to the traditional lithium metal rolling process, this application embodiment can form a thinner metal layer, thereby reducing the overall volume and weight of the negative electrode and increasing the energy density of the battery. Simultaneously, the negative electrode active material layer is attached to the substrate surface via magnetron sputtering, increasing the bonding strength and interface stability. The edges of the negative electrode active material layer are controllable, with fewer surface defects, resulting in high interface stability, which facilitates the formation of a stable SEI film, reduces volume expansion, and improves the battery's energy density.

[0041] In some embodiments, the electrode substrate material includes a conductive material (specifically, at least one of copper, aluminum, and stainless steel) or an insulating material (specifically, a polymer material, such as at least one of polypropylene, polyimide, polyethylene, and polyethylene terephthalate). When the substrate material is an insulating material, the functional layer includes at least a conductive material layer (i.e., a current collector layer) magnetron sputtered onto the substrate surface and a negative electrode active material layer attached to the conductive material layer.

[0042] In this embodiment, the electrode substrate material is an insulating material, which facilitates weight reduction, provides support and buffering, and possesses a certain degree of toughness, making it easy to process. The conductive material is used to enable the transmission of current from the electrode active material to the external circuit.

[0043] In some embodiments, the material of the current collector layer includes at least one of copper and aluminum; and / or, the active material includes at least one of metallic and non-metallic materials.

[0044] In this embodiment, the material of the current collector layer includes at least one of copper and aluminum. It is functionally modified on the substrate layer of the insulating material to serve as a current collector. Then, a multilayer electrode is formed by magnetron sputtering of the active material layer, which can be directly used as the electrode of the battery.

[0045] In this embodiment, the active material layer can be magnetron sputtered to attach at least one type of metal active material, at least one type of non-metal active material, or a combination of metal and non-metal active materials to form an integrated multilayer electrode sheet, which can be directly used as the electrode sheet of the battery, thereby improving the energy density of the battery.

[0046] In some embodiments, the metallic material includes at least one of lithium, aluminum, tin, and sodium; and / or, the non-metallic material includes at least one of silicon and carbon.

[0047] In this application embodiment, at least one of lithium, aluminum, tin, and sodium can be attached to a substrate or current collector layer via magnetron sputtering. When different types of metal materials are selected, one metal layer can be first attached to the substrate by magnetron sputtering, and then another metal layer can be attached by magnetron sputtering to form a multilayer electrode. For non-metallic material layers, at least one of silicon and carbon can be attached to the substrate by sputtering. When different types of non-metallic materials are selected, one non-metallic layer can be first attached to the substrate by magnetron sputtering, and then another non-metallic layer can be attached by magnetron sputtering to form a multilayer electrode. When a combination of metal and non-metallic materials is used, a composite multilayer structure of metal and non-metallic layers can be formed on the substrate by magnetron sputtering.

[0048] In some embodiments, the thickness of the substrate is 2 μm to 20 μm; and / or, the thickness of the functional layer is 0.5 μm to 50 μm.

[0049] In this embodiment, the thickness of the substrate meets the above conditions, which is beneficial for balancing the safety performance of the substrate and the energy density of the battery. It is also beneficial for reducing the thickness and increasing the energy density of the battery while ensuring that the substrate has a certain mechanical strength and safety. In specific examples, the substrate thickness is 2μm, 2.5μm, 3μm, 3.5μm, 4μm, 4.5μm, 5μm, 5.5μm, 6μm, 6.5μm, 7μm, 7.5μm, 8μm, 8.5μm, 9μm, 9.5μm, 10μm, 10.5μm, 11μm, 11.5μm, 12μm, 12.5μm, 13μm, 13.5μm, 14μm, 14.5μm, 15μm, 15.5μm, 16μm, 16.5μm, 17μm, 17.5μm, 18μm, 18.5μm, 19μm, 19.5μm, 20μm, etc. In specific examples, the thickness of the functional layer is 0.5μm, 1μm, 1.5μm, 2μm, 4μm, 6μm, 8μm, 10μm, 12μm, 14μm, 16μm, 18μm, 20μm, 22μm, 24μm, 26μm, 28μm, 30μm, 32μm, 34μm, 36μm, 38μm, 40μm, 42μm, 44μm, 46μm, 48μm, 50μm, etc.

[0050] Furthermore, the thickness of the substrate is 5 μm to 7 μm. In the embodiments of this application, the thickness of the substrate meets further limiting conditions, which is beneficial to obtaining higher battery energy density. In specific examples, the thickness of the substrate is 5 μm, 5.2 μm, 5.4 μm, 5.6 μm, 5.8 μm, 6 μm, 6.2 μm, 6.4 μm, 6.5 μm, 6.6 μm, 7 μm, etc.

[0051] In this embodiment, the thickness of the functional layer meets the above conditions, ensuring the normal charging and discharging function of the negative electrode active material layer while reducing the energy density of the battery. Specifically, the thickness of the negative electrode active material layer is 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, etc.

[0052] Furthermore, the thickness of the functional layer is 0.8 μm to 1 μm, which helps to reduce the battery energy density and ensure good electrochemical performance. In specific examples, the thickness of the functional layer is 0.8 μm, 0.82 μm, 0.84 μm, 0.85 μm, 0.86 μm, 0.88 μm, 0.9 μm, 0.92 μm, 0.94 μm, 0.96 μm, 0.98 μm, 1 μm, etc.

[0053] In some embodiments, the substrate and functional layers can be combined in any way, including but not limited to at least one of Cu-Li multilayer electrode, Cu-Al multilayer electrode, Cu-Sn multilayer electrode, Al-Na multilayer electrode, Cu-Si multilayer electrode, Cu-C multilayer electrode, SUS-C multilayer electrode, Al-C multilayer electrode, Cu-Li-C multilayer electrode, Cu-Al-C multilayer electrode, PP-Cu-Li multilayer electrode, and PI-Cu-Li multilayer electrode.

[0054] The aforementioned "Cu-Li multilayer electrode" refers to a multilayer electrode with a lithium metal layer attached to the surface of a copper substrate; "Cu-Al multilayer electrode" refers to a multilayer electrode with an aluminum metal layer attached to the surface of a copper substrate; "Cu-Sn multilayer electrode" refers to a multilayer electrode with a tin metal layer attached to the surface of a copper substrate; "Al-Na multilayer electrode" refers to a multilayer electrode with a sodium metal layer attached to the surface of an aluminum substrate; "Cu-Si multilayer electrode" refers to a multilayer electrode with a silicon nonmetallic layer attached to the surface of a copper substrate; and "Cu-C multilayer electrode" refers to a multilayer electrode with a graphite carbon nonmetallic layer attached to the surface of a copper substrate. Electrode types include: "SUS-C multilayer electrode" (stainless steel substrate with carbon nonmetallic layer attached), "Al-C multilayer electrode" (aluminum substrate with carbon nonmetallic layer attached), "Cu-Li-C multilayer electrode" (copper substrate with lithium metal layer and carbon nonmetallic layer attached sequentially), "Cu-Al-C multilayer electrode" (copper substrate with aluminum metal layer and carbon nonmetallic layer attached sequentially), "PP-Cu-Li multilayer electrode" (PP (polypropylene) substrate with copper metal layer and lithium metal layer attached), and "PI-Cu-Li multilayer electrode" (PI (polyimide) substrate with copper metal layer and lithium metal layer attached).

[0055] Cu-Li multilayer electrodes are used as negative electrodes in lithium-ion batteries, with Cu as the conductive layer and Li as the active material layer for lithium insertion / extraction.

[0056] Cu-Al multilayer electrodes are used as negative electrode sheets in lithium-ion batteries. Cu serves as the conductive layer, and Al can form an Al-Li alloy with Li, serving as the active material layer for lithium insertion / extraction. Li is provided by the active material in the positive electrode sheet. During charging, lithium is inserted / extracted from the positive electrode into the active material layer of the negative electrode. The Cu-Al multilayer electrode sheet provided in this application is used as a negative electrode sheet, and Al can form an alloy with the Li extracted / extracted from the positive electrode, serving as the active material for the negative electrode.

[0057] Cu-Sn multilayer electrodes are used as negative electrode sheets in lithium-ion batteries. Sn serves as a conductive layer and can form a Sn-Li alloy with Li, acting as the active material layer for lithium intercalation / deintercalation. Li is provided by the active material in the positive electrode sheet. During charging, lithium is intercalated / deintercalated from the positive electrode into the active material layer of the negative electrode. The Cu-Sn multilayer electrodes provided in this application are used as negative electrode sheets, and Sn can form an alloy with the Li intercalated / deintercalated from the positive electrode, serving as the active material for the negative electrode.

[0058] Al-Na multilayer electrodes are used as negative electrodes in sodium-ion batteries, with Al as the conductive layer and Na as the active material layer for sodium insertion / extraction.

[0059] Cu-Si multilayer electrodes are used as negative electrode sheets in lithium-ion batteries. Cu serves as the conductive layer, while elemental silicon, silicon-containing composites, or silicon oxides are used as the active material layer. Specifically, if monocrystalline or polycrystalline silicon is used as the target material, a Si elemental sputtering layer is formed as the active material layer for lithium insertion / extraction; if silicon-carbon is used as the target material, a C / Si composite sputtering layer is formed as the active material layer for lithium insertion / extraction; and if silicon oxide is used as the target material, a SiO₂ layer is formed. x The sputtered layer serves as the active material layer for lithium insertion / extraction.

[0060] Cu-C multilayer electrodes are used as negative electrodes in lithium-ion batteries, with Cu as the conductive layer and C (graphite) as the active material layer for lithium insertion / extraction.

[0061] SUS-C multilayer electrodes are used as negative electrodes in lithium-ion batteries. SUS serves as the conductive layer, and C (graphite) serves as the active material layer for lithium insertion and extraction. They have good conductivity and stability. A passivation film is easily formed on the SUS surface to protect it from corrosion. They are low in cost and simple to manufacture.

[0062] Cu-Li-C multilayer electrodes are used as negative electrodes in lithium-ion batteries, with Cu as the conductive layer and Li and C (graphite) as active material layers for lithium insertion / extraction.

[0063] Cu-Al-C multilayer electrodes are used as negative electrodes in lithium-ion batteries, with Cu as the conductive layer and Li and C (graphite) as active material layers for lithium insertion / extraction.

[0064] PP-Cu-Li multilayer electrode sheets are used as negative electrode sheets for lithium-ion batteries. PP is used as the substrate, Cu is used as the conductive layer, and Li is used as the active material layer for lithium insertion / extraction.

[0065] PI-Cu-Li multilayer electrode sheets are used as negative electrode sheets for lithium-ion batteries. PI is used as the substrate, Cu is used as the conductive layer, and Li is used as the active material layer for lithium insertion / extraction.

[0066] In some embodiments, the multilayer electrode is at least one of Al-Na multilayer electrode, Al-C multilayer electrode, Cu-Li-C multilayer electrode, Cu-Al-C multilayer electrode, PP-Cu-Li multilayer electrode, and PI-Cu-Li multilayer electrode.

[0067] Al-Na multilayer electrodes are used as negative electrodes in sodium-ion batteries, with Al as the conductive layer and Na as the active material layer for sodium insertion / extraction.

[0068] Al-C multilayer electrodes are used as negative electrodes in sodium-ion batteries. Al serves as the conductive layer, and C serves as the active material layer for lithium-sodium intercalation / deintercalation. By magnetron sputtering a hard carbon layer onto Al, it can be directly used as a negative electrode in sodium-ion batteries, eliminating the need for traditional battery manufacturing processes such as slurry preparation, coating, rolling, and baking, thus shortening the battery manufacturing process. Simultaneously, the coating exhibits strong adhesion and allows for the fabrication of thinner electrodes, which is beneficial for improving rate performance.

[0069] Cu-Li-C multilayer electrodes are used as negative electrodes in lithium-ion batteries, with Cu as the conductive layer and Li and C (graphite) as active material layers for lithium insertion / extraction.

[0070] Cu-Al-C multilayer electrodes are used as negative electrodes in lithium-ion batteries, with Cu as the conductive layer and Li and C (graphite) as active material layers for lithium insertion / extraction.

[0071] PP-Cu-Li multilayer electrode sheets are used as negative electrode sheets for lithium-ion batteries. PP is used as the substrate, Cu is used as the conductive layer, and Li is used as the active material layer for lithium insertion / extraction.

[0072] PI-Cu-Li multilayer electrode sheets are used as negative electrode sheets for lithium-ion batteries. PI is used as the substrate, Cu is used as the conductive layer, and Li is used as the active material layer for lithium insertion / extraction.

[0073] The second aspect of this application provides a method for preparing a multilayer electrode sheet, wherein at least one coating layer is sputtered as a functional layer on the surface of a substrate using a vacuum magnetron sputtering method to prepare the aforementioned multilayer electrode sheet.

[0074] This application employs magnetron sputtering to prepare multilayer electrodes, directly forming a negative electrode active material layer on the surface of the current collector via magnetron sputtering. This creates an integrated structure that combines the functions of the current collector and the negative electrode active material, making it suitable for use as both positive and negative electrode sheets in a battery. Figure 2As shown, a layer of active material is magnetron sputtered onto a conductive substrate such as copper, aluminum, or stainless steel to form a double-layer electrode. This application employs magnetron sputtering to prepare multilayer electrodes, which facilitates the obtaining of thin and lightweight functional layers, especially the active material layer. This reduces the overall volume and weight of the electrode, thereby increasing the energy density of the battery. Simultaneously, the active material layer adheres to the substrate surface via magnetron sputtering, increasing the bonding strength and interfacial stability. The active material layer also exhibits fewer surface defects and higher interfacial stability, which is beneficial for forming a stable SEI film, reducing volume expansion, and further improving the battery's energy density.

[0075] The electrode substrate material includes a conductive material (specifically, at least one of copper, aluminum, and stainless steel) or an insulating material (specifically, a polymer material, such as at least one of polypropylene, polyimide, polyethylene, and polyethylene terephthalate). When the substrate material is an insulating material, the functional layer includes at least a conductive material layer (i.e., a current collector layer) magnetron sputtered onto the substrate surface and a negative electrode active material layer attached to the conductive material layer. Figure 3 As shown, a current collector layer is magnetron sputtered onto an insulating material substrate, followed by a layer of active material, forming a three-layer electrode.

[0076] Furthermore, the embodiments of this application employ magnetron sputtering to prepare multilayer electrodes, which can be fabricated with mask assistance to produce multilayer electrodes of various shapes to meet the needs of batteries with specific shapes and patterns. The operation is flexible and convenient. Figure 4 As shown.

[0077] Specifically, in this embodiment, the control device is in a vacuum state, and then a pure inert gas (such as argon) is introduced. Magnetron sputtering deposition technology is used to bombard the target material, causing the target atoms to sputter and deposit a coating on the substrate surface. More specifically, a magnet generates a helical magnetic field to accelerate electrons in an electron avalanche. Under the influence of the electric field, the electrons collide with argon atoms on their way to the anode, ionizing the argon atoms into new electrons and argon ions. These argon ions bombard the surface of the target material, giving the target atoms sufficient energy to sputter out; the sputtered atoms deposit on the substrate surface to form a coating.

[0078] Furthermore, the purity of the target material (i.e., the material of the functional layer) is >99.9%.

[0079] In some implementations, the control parameters in vacuum magnetron sputtering include any one of the following (1) to (3):

[0080] (1) Voltage: 1000V~5000V; In specific examples, the voltage is 1000V, 1050V, 1100V, 1150V, 1200V, 1250V, 1300V, 1350V, 1400V, 1450V, 1500V, 1600V, 1700V, 1800V, 1900V, 1900V, 2000V, 2200V, 2400V, 2600V, 2800V, 3000V, 3200V, 3400V, 3600V, 3800V, 4000V, 4200V, 4400V, 4600V, 4800V, 5000V, etc.

[0081] (2) Vacuum degree: 4×10 -3 Below Pa; in a specific example, the vacuum degree is 4 × 10⁻⁶. -3 Pa, 3.5 × 10 -3 Pa, 3×10 -3 Pa, 2.5 × 10 -3 Pa, 2×10 -3 Pa, 1.5 × 10 -3 Pa, 1×10 -3 Pa, 0.5×10 -3 Pa, 0.1×10 -3 Pa, etc.

[0082] (3) The magnetic control speed is 5m / min to 8m / min; in specific examples, the magnetic control speed is 5m / min, 5.5m / min, 6m / min, 6.5m / min, 7m / min, 7.5m / min, 8m / min, etc.

[0083] In this application embodiment, control parameters such as voltage, vacuum level, and / or magnetron sputtering speed meet the above conditions to form a functional layer with a smooth surface and few or no surface defects. This also improves the bonding between the functional layer and the substrate, and among the functional layers themselves, enhancing the stability of the bonding interface and thus increasing the energy density of the battery. Further, in the vacuum magnetron sputtering method, the control parameters include: voltage of 1000V to 1500V, and vacuum level of 4×10⁻⁶. -3 Below Pa, the magnetic control speed is 5m / min to 8m / min.

[0084] In some implementations, the control parameters in vacuum magnetron sputtering include any one of the following (1) to (3):

[0085] (1) Voltage: 1200V~1400V; in specific examples, the voltage is 1220V, 1240V, 1260V, 1280V, 1300V, 1320V, 1340V, 1360V, 1380V, 1400V, etc.

[0086] (2) Vacuum degree: 3×10 -3 Pa~4×10 -3 Pa; in the specific example, the vacuum degree is 4 × 10⁻⁶. -3 Pa, 3.8 × 10 - 3 Pa, 3.6 × 10 -3 Pa, 3.4 × 10 -3 Pa, 3.2 × 10 -3 Pa, 3×10 -3 Pa, etc.

[0087] (3) The magnetic control speed is 6m / min to 7m / min; in specific examples, the magnetic control speed is 6m / min, 6.2m / min, 6.4m / min, 6.6m / min, 6.7m / min, 7m / min, etc.

[0088] In the embodiments of this application, the control parameters such as voltage, vacuum degree and / or magnetron speed meet the above conditions, which is beneficial to obtain a functional layer with a smaller thickness, reduce surface defects of the functional layer, improve the bonding strength and interface stability of each layer, and thus further improve the energy density of the battery.

[0089] In some embodiments, the preparation of multilayer electrodes by vacuum magnetron sputtering includes the following steps:

[0090] S1000: The substrate is attached to the surface of the cooling drum.

[0091] S2000: Adjusts process parameters to sputter a coating onto one side of the substrate using single-sided magnetron sputtering. Specific examples include controlling the substrate operating temperature to 20℃~25℃; the flow rate of high-purity argon gas to 130SCCM~300SCCM, with a purity of 99.999%; the voltage to 1000V~1500V; and the vacuum level to 4×10⁻⁶. -3 For speeds below Pa, the magnetron speed is 5 m / min to 8 m / min. Specific examples include sputtered coating thicknesses of 1 nm to 100 nm.

[0092] S3000: The functional layer achieves a predetermined thickness through multiple sputtering processes. A specific example is a functional layer thickness of 0.5 μm to 1 μm.

[0093] Furthermore, during substrate pretreatment, plasma sterilization equipment can be used for plasma treatment to ensure sufficient cleanliness of the substrate surface and adhesion of the sputtered metal nanolayers. Specific sputtering patterns can also be achieved through mask design.

[0094] In some implementations, all metal targets are pure metal targets.

[0095] In some embodiments, the target material C in the Al-C multilayer electrode is a hard carbon target; in the Cu-C multilayer electrode, the target material C is a graphite target, which is either crystalline graphite or amorphous graphite.

[0096] In some embodiments, the silicon-based target material is any one of monocrystalline silicon, polycrystalline silicon, silicon suboxide, and silicon-carbon.

[0097] A third aspect of this application provides a battery comprising the multilayer electrode sheet described above, or the multilayer electrode sheet obtained by the preparation method described above.

[0098] The battery provided in this application embodiment includes the above-mentioned multilayer electrode sheet, exhibits good electrochemical performance, and has a high energy density.

[0099] The present invention will now be described with reference to specific embodiments. It should be noted that these embodiments are merely descriptive and do not limit the invention in any way. The reagents used in the embodiments are all from Aladdin Biochemical Technology Co., Ltd.

[0100] Example 1

[0101] This embodiment provides a multilayer electrode, a Cu-Li multilayer electrode, and the specific preparation method is shown below:

[0102] Step 1: Pretreatment. The copper foil substrate is subjected to plasma treatment using a plasma sterilization device to ensure sufficient cleanliness of the substrate surface and adhesion of the sputtered metal nanolayer.

[0103] Step 2: Perform magnetron sputtering to prepare a lithium metal thin film. A copper foil substrate is bonded to the surface of a cooling drum. The substrate operating temperature is controlled at 20°C, the flow rate of high-purity argon gas is 300 SCCM, and the purity is 99.999%; the voltage is 1200V, and the vacuum degree is 3×10⁻⁶. -3 At a speed of 6 m / min, a lithium target was mounted on a power supply target head, and magnetron sputtering was performed under power to deposit a coating with a thickness of 1–100 nm. This process was repeated multiple times to form a 1 μm coating. Finally, a Cu-Li multilayer electrode with the target thickness was obtained.

[0104] Example 2

[0105] This embodiment provides a multilayer electrode, a Cu-Al multilayer electrode, and the specific preparation method is shown below:

[0106] Step 1: Pretreatment. The copper foil substrate is subjected to plasma treatment using a plasma sterilization device to ensure sufficient cleanliness of the substrate surface and adhesion of the sputtered metal nanolayer.

[0107] Step 2: Perform magnetron sputtering to prepare a thin aluminum film. A copper foil substrate is bonded to the surface of a cooling drum. The substrate operating temperature is controlled at 20°C, the flow rate of high-purity argon gas is 300 SCCM, and the purity is 99.999%; the voltage is 1200V, and the vacuum degree is 3×10⁻⁶. -3 At a speed of 6 m / min, an aluminum target is mounted on a power supply target head, and magnetron sputtering is performed under power to deposit a coating with a thickness of 1–100 nm. This process is repeated multiple times to form a 1 μm coating. Finally, a Cu-Al multilayer electrode with the target thickness is obtained.

[0108] Example 3

[0109] This embodiment provides a multilayer electrode, a Cu-Sn multilayer electrode, and the specific preparation method is shown below:

[0110] Step 1: Pretreatment. The copper foil substrate is subjected to plasma treatment using a plasma sterilization device to ensure sufficient cleanliness of the substrate surface and adhesion of the sputtered metal nanolayer.

[0111] Step 2: Perform magnetron sputtering to prepare a thin film of metallic tin. A copper foil substrate is bonded to the surface of a cooling drum. The substrate operating temperature is controlled at 20°C, the flow rate of high-purity argon gas is 300 SCCM, and the purity is 99.999%; the voltage is 1200V, and the vacuum degree is 3×10⁻⁶. -3 At a speed of 6 m / min, a tin target is mounted on a power target head, and magnetron sputtering is performed under power to deposit a coating with a thickness of 1–100 nm. This process is repeated multiple times to form a 1 μm coating. Finally, a Cu-Sn multilayer electrode with the target thickness is obtained.

[0112] Example 4

[0113] This embodiment provides a multilayer electrode, a Cu-Si multilayer electrode, and the specific preparation method is shown below:

[0114] Step 1: Pretreatment. The copper foil substrate is subjected to plasma treatment using a plasma sterilization device to ensure sufficient cleanliness of the substrate surface and adhesion of the sputtered non-metallic nanolayer.

[0115] Step 2: Perform magnetron sputtering to prepare a non-metallic silicon thin film. A copper foil substrate is bonded to the surface of the cooling drum. The substrate operating temperature is controlled at 20°C, the flow rate of high-purity argon gas is 300 SCCM, and the purity is 99.999%; the voltage is 1200V, and the vacuum degree is 3×10⁻⁶. -3 At a speed of 6 m / min, a silicon target is mounted on a power target head, and magnetron sputtering is performed under power to deposit a layer with a thickness of 1–100 nm. This process is repeated multiple times to form a 1 μm layer. Finally, a Cu-Si multilayer electrode with the target thickness is obtained.

[0116] Example 5

[0117] This embodiment provides a multilayer electrode, a Cu-C multilayer electrode, and the specific preparation method is shown below:

[0118] Step 1: Pretreatment. The copper foil substrate is subjected to plasma treatment using a plasma sterilization device to ensure sufficient cleanliness of the substrate surface and adhesion of the sputtered non-metallic nanolayer.

[0119] Step 2: Perform magnetron sputtering to prepare a non-metallic graphite carbon thin film. A copper foil substrate is bonded to the surface of the cooling drum. The substrate operating temperature is controlled at 20℃, the flow rate of high-purity argon gas is 300 SCCM, and the purity is 99.999%; the voltage is 1200V, and the vacuum degree is 3×10⁻⁶. -3 At a speed of 6 m / min, a graphite carbon target is mounted on a power supply target head, and magnetron sputtering is performed under power to deposit a coating with a thickness of 1–100 nm. This process is repeated multiple times to form a 1 μm coating. Finally, a Cu-C multilayer electrode with the target thickness is obtained.

[0120] Example 6

[0121] This embodiment provides a multilayer electrode, a SUS-C multilayer electrode, and the specific preparation method is shown below:

[0122] Step 1: Pretreatment. The SUS substrate is subjected to plasma treatment using a plasma sterilization device to ensure sufficient cleanliness of the substrate surface and adhesion of the sputtered non-metallic nanolayer.

[0123] Step 2: Perform magnetron sputtering to prepare a non-metallic graphite carbon thin film. The SUS substrate is bonded to the surface of the cooling drum. The substrate operating temperature is controlled at 20℃, the flow rate of high-purity argon gas is 300 SCCM, and the purity is 99.999%; the voltage is 1200V, and the vacuum degree is 3×10⁻⁶. -3 At a speed of 6 m / min, a graphite carbon target is mounted on a power supply target head, and magnetron sputtering is performed under power to deposit a coating with a thickness of 1–100 nm. This process is repeated multiple times to form a 1 μm coating. Finally, a SUS-C multilayer electrode with the target thickness is obtained.

[0124] Example 7

[0125] This embodiment provides a multilayer electrode, a Cu-Li-C multilayer electrode, and the specific preparation method is shown below:

[0126] Step 1: Pretreatment. The copper foil substrate is subjected to plasma treatment using a plasma sterilization device to ensure sufficient cleanliness of the substrate surface and adhesion of the sputtered metal nanolayer.

[0127] Step 2: Perform magnetron sputtering to prepare a lithium metal thin film. A copper foil substrate is bonded to the surface of a cooling drum. The substrate operating temperature is controlled at 20°C, the flow rate of high-purity argon gas is 300 SCCM, and the purity is 99.999%; the voltage is 1200V, and the vacuum degree is 3×10⁻⁶. -3 At Pa, with a magnetron sputtering speed of 6 m / min, a lithium target is mounted on a power target head, and magnetron sputtering is performed under power to deposit a coating with a thickness of 1–100 nm. This process is repeated multiple times to form a 1 μm coating.

[0128] Step 3: The composite substrate obtained in Step 2 is subjected to magnetron sputtering to prepare a non-metallic graphite carbon thin film. The operating temperature of the composite substrate is controlled at 20℃, the flow rate of high-purity argon gas is 300 SCCM, and the purity is 99.999%; the voltage is 1200V, and the vacuum degree is 3×10⁻⁶. -3 At a speed of 6 m / min, a graphite carbon target is mounted on a power supply target head, and magnetron sputtering is performed under power to deposit a coating with a thickness of 1–100 nm. This process is repeated multiple times to form a 1 μm coating. Finally, a Cu-Li-C multilayer electrode with the target thickness is obtained.

[0129] Example 8

[0130] This embodiment provides a multilayer electrode, a Cu-Al-C multilayer electrode, and the specific preparation method is shown below:

[0131] Step 1: Pretreatment. The copper foil substrate is subjected to plasma treatment using a plasma sterilization device to ensure sufficient cleanliness of the substrate surface and adhesion of the sputtered metal nanolayer.

[0132] Step 2: Perform magnetron sputtering to prepare a thin aluminum film. A copper foil substrate is bonded to the surface of a cooling drum. The substrate operating temperature is controlled at 20°C, the flow rate of high-purity argon gas is 300 SCCM, and the purity is 99.999%; the voltage is 1200V, and the vacuum degree is 3×10⁻⁶. -3 At Pa, with a magnetron speed of 6 m / min, an aluminum target is mounted on a power target head, and magnetron sputtering is performed with power applied to deposit a coating with a thickness of 1–100 nm. This process is repeated multiple times to form a 1 μm coating.

[0133] Step 3: The composite substrate obtained in Step 2 is subjected to magnetron sputtering to prepare a non-metallic graphite carbon thin film. The operating temperature of the composite substrate is controlled at 20℃, the flow rate of high-purity argon gas is 300 SCCM, and the purity is 99.999%; the voltage is 1200V, and the vacuum degree is 3×10⁻⁶. -3 At a speed of 6 m / min, a graphite carbon target is mounted on a power supply target head, and magnetron sputtering is performed under power to deposit a coating with a thickness of 1–100 nm. This process is repeated multiple times to form a 1 μm coating. Finally, a Cu-Al-C multilayer electrode with the target thickness is obtained.

[0134] Example 9

[0135] This embodiment provides a multilayer electrode, a PP-Cu-Li multilayer electrode, and the specific preparation method is shown below:

[0136] Step 1: Pretreatment. The polymer PP substrate is subjected to plasma treatment using a plasma sterilization device to ensure sufficient cleanliness of the substrate surface and adhesion of the sputtered metal nanolayer.

[0137] Step 2: Perform magnetron sputtering to prepare a thin copper film. PP substrate is laminated onto the surface of the cooling drum. The substrate operating temperature is controlled at 20℃, the flow rate of high-purity argon gas is 300 SCCM, and the purity is 99.999%; the voltage is 1200V, and the vacuum degree is 3×10⁻⁶. -3 Pa, magnetron speed of 6 m / min, copper target material is mounted on power target head, magnetron sputtering is performed by powering on, depositing a coating thickness of 1 to 100 nm. This process is repeated multiple times to form a 1 μm coating.

[0138] Step 3: Magnetron sputtering is performed on the composite substrate obtained in Step 2 to prepare a lithium metal thin film. The operating temperature of the composite substrate is controlled at 20℃, the flow rate of high-purity argon gas is 300 SCCM, and the purity is 99.999%; the voltage is 1200V, and the vacuum degree is 3×10⁻⁶. - 3 At a speed of 6 m / min, a lithium target was mounted on a power supply target head, and magnetron sputtering was performed under power to deposit a coating with a thickness of 1–100 nm. This process was repeated multiple times to form a 1 μm coating. Finally, a PP-Cu-Li multilayer electrode with the target thickness was obtained.

[0139] Example 10

[0140] This embodiment provides a multilayer electrode, a PI-Cu-Li multilayer electrode, and the specific preparation method is shown below:

[0141] Step 1: Pretreatment. The polymer PI substrate is subjected to plasma treatment using a plasma sterilization device to ensure sufficient cleanliness of the substrate surface and adhesion of the sputtered metal nanolayer.

[0142] Step 2: Perform magnetron sputtering to prepare a thin copper film. The PI substrate is bonded to the surface of the cooling drum. The substrate operating temperature is controlled at 20℃, the flow rate of high-purity argon gas is 300 SCCM, and the purity is 99.999%; the voltage is 1200V, and the vacuum degree is 3×10⁻⁶. -3 Pa, magnetron speed of 6 m / min, copper target material is mounted on power target head, magnetron sputtering is performed by powering on, depositing a coating thickness of 1 to 100 nm. This process is repeated multiple times to form a 1 μm coating.

[0143] Step 3: Magnetron sputtering is performed on the composite substrate obtained in Step 2 to prepare a lithium metal thin film. The operating temperature of the composite substrate is controlled at 20℃, the flow rate of high-purity argon gas is 300 SCCM, and the purity is 99.999%; the voltage is 1200V, and the vacuum degree is 3×10⁻⁶. - 3 At a speed of 6 m / min, a lithium target was mounted on a power target head, and magnetron sputtering was performed under power to deposit a coating with a thickness of 1–100 nm. This process was repeated multiple times to form a 1 μm coating. Finally, a PI-Cu-Li multilayer electrode with the target thickness was obtained.

[0144] Example 11

[0145] This embodiment provides a multilayer electrode, specifically an Al-Na multilayer electrode, and the specific preparation method is shown below:

[0146] Step 1: Pretreatment. The aluminum foil substrate is subjected to plasma treatment using a plasma sterilization device to ensure sufficient cleanliness of the substrate surface and adhesion of the sputtered metal nanolayer.

[0147] Step 2: Perform magnetron sputtering to prepare a sodium thin film. An aluminum foil substrate is bonded to the surface of a cooling drum. The substrate operating temperature is controlled at 20°C, the flow rate of high-purity argon gas is 300 SCCM (purity 99.999%), the voltage is 1200V, the vacuum degree is 3×10⁻³ Pa, and the magnetron speed is 6 m / min. The sodium target is mounted on the power target head, and magnetron sputtering is performed to deposit a layer with a thickness of 1–100 nm. This process is repeated multiple times to form a 1 μm layer. Finally, an Al-Na multilayer electrode with the target thickness is obtained.

[0148] Example 12

[0149] This embodiment provides a multilayer electrode, specifically an Al-C multilayer electrode, and the specific preparation method is shown below:

[0150] Step 1: Pretreatment. The aluminum foil substrate is subjected to plasma treatment using a plasma sterilization device to ensure sufficient cleanliness of the substrate surface and adhesion of the sputtered metal nanolayer.

[0151] Step 2: Magnetron sputtering to prepare hard carbon thin films. An aluminum foil substrate is bonded to the surface of a cooling drum. The substrate operating temperature is controlled at 20℃, the flow rate of high-purity argon gas is 300 SCCM (purity 99.999%), the voltage is 1200V, the vacuum degree is 3×10⁻³ Pa, and the magnetron speed is 6 m / min. The hard carbon target is mounted on the power target head, and magnetron sputtering is performed to deposit a coating thickness of 1–100 nm. This process is repeated multiple times to form a 1 μm coating. Finally, an Al-C multilayer electrode with the target thickness is obtained.

[0152] Example 13

[0153] This embodiment provides a multilayer electrode, a Cu-Li-C multilayer electrode, and the specific preparation method is shown in Example 7, except that the voltage in step 3 is 2000V.

[0154] Battery manufacturing

[0155] The specific method is as follows:

[0156] Lithium / sodium ion batteries were prepared using the multilayer electrodes prepared in Example 113 through the following steps:

[0157] Select ternary material NCM (LiNi) 0.65 Mn 0.2 Co 0.15 Using O2 or sodium nickel cobalt manganese oxide (Na2NiFeMnO6) as the positive electrode, the positive electrode active material is mixed with the binder PVDF (polyvinylidene fluoride) and the conductive agent (carbon black + conductive graphite = 1:1, mass ratio) in NMP (N-methylpyrrolidone) solvent to prepare a positive electrode slurry. The ratio of positive electrode active material: binder: conductive agent is 96:2:2, and the total amount of powder: solvent is 100:45. The positive electrode slurry is then coated onto aluminum foil and dried in a vacuum drying oven at 85°C to obtain the positive electrode sheet.

[0158] For lithium-ion batteries, the positive electrode active material is [material name missing]; for sodium-ion batteries, the positive electrode active material is [material name missing].

[0159] The multilayer electrode sheet designed by magnetron sputtering in the embodiments of this application is selected as the negative electrode sheet of lithium-ion battery.

[0160] For lithium-ion batteries, the electrolyte composition is: EC (ethylene carbonate): EMC (ethyl methyl carbonate): DMC (dimethyl carbonate) (volume ratio 25:5:70) + 1.5M LiPF6 + 2wt% VC (ethylene carbonate) + 1wt% DTD (ethylene sulfate); for sodium-ion batteries, the electrolyte composition is: 1.0M NaClO4 + EC (ethylene carbonate): DMC (dimethyl carbonate) = 1:1 (volume ratio) + 5.0% FEC (fluoroethylene carbonate).

[0161] The above-mentioned positive electrode, negative electrode, separator (PP, polypropylene) and lithium-ion electrolyte are assembled into a lithium-ion battery; the above-mentioned positive electrode, negative electrode, separator (PP, polypropylene) and sodium-ion electrolyte are assembled into a sodium-ion battery.

[0162] Comparative Example 1

[0163] A lithium-ion battery was prepared using a conventional current collector (conventional copper foil) prepared in a comparative proportion through the following steps: a ternary material NCM was selected as the positive electrode, and it was mixed with a binder and a conductive agent in NMP solvent to prepare a positive electrode slurry; the positive electrode slurry was then coated onto conventional aluminum foil, and dried in a vacuum drying oven at 85°C to obtain a positive electrode sheet.

[0164] Graphite is selected as the negative electrode material. It is mixed with binder and conductive agent in deionized water to prepare a negative electrode slurry. The negative electrode slurry is then coated on traditional copper foil or aluminum foil and dried in a vacuum drying oven at 85°C to obtain the negative electrode sheet.

[0165] The above-mentioned positive electrode, negative electrode, separator and lithium-ion electrolyte are assembled into a lithium-ion battery.

[0166] Comparative Example 2

[0167] A lithium-ion battery was prepared using a conventional current collector (conventional copper foil) prepared in a comparative proportion through the following steps: sodium nickel cobalt manganese oxide was selected as the positive electrode, and it was mixed with a binder and a conductive agent in NMP solvent to prepare a positive electrode slurry; the positive electrode slurry was then coated onto conventional aluminum foil, and dried in a vacuum drying oven at 85°C to obtain a positive electrode sheet.

[0168] Graphite or hard carbon is selected as the negative electrode material. It is mixed with binder and conductive agent in deionized water to prepare a negative electrode slurry. The negative electrode slurry is then coated on a traditional aluminum foil and dried in a vacuum drying oven at 85°C to obtain the negative electrode sheet.

[0169] The above-mentioned positive electrode, negative electrode, separator and electrolyte are assembled into a sodium-ion battery.

[0170] I. Performance Testing

[0171] 1. Test Method: The energy density of the above-mentioned lithium-ion batteries was tested according to the battery energy density test method in GB / T 31486-2015, "Electrical Performance Requirements and Test Methods for Power Batteries for Electric Vehicles". The energy density results are shown in Table 1.

[0172] 2. Test results.

[0173] The test results are shown in Table 1.

[0174] Table 1 Performance test results of samples prepared in each embodiment

[0175]

[0176] As can be seen from the data in Table 1, the energy density of the batteries prepared using the multilayer electrodes of Examples 1 to 10 is greater than that of the battery prepared using Comparative Example 1. Furthermore, the energy density of the batteries prepared using the multilayer electrodes of Examples 11 to 12 is significantly greater than that of the battery prepared using the conventional current collector system of Comparative Example 2. This indicates that, compared to existing multilayer electrodes and conventional current collectors, the multilayer electrodes obtained using the technical solution of this invention can improve the energy density of the battery. The energy density of the battery prepared using the multilayer electrode of Example 7 is greater than that of the battery prepared using Example 13, demonstrating that the voltage of the magnetron sputtering deposition functional layer affects the coating effect and thus the cell energy density.

[0177] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A multilayer electrode sheet, characterized in that, include: The matrix material includes at least one of copper, aluminum, stainless steel, polypropylene, polyimide, polyethylene, and polyethylene terephthalate; At least one functional layer is attached to the surface of the substrate by magnetron sputtering, the functional layer including at least a negative electrode active material layer; optionally, the functional layer further includes a current collector layer located between the active material layer and the substrate.

2. The multilayer electrode sheet according to claim 1, characterized in that, The material of the negative electrode active material layer includes at least one of metallic and non-metallic materials; And / or, the material of the current collector layer includes at least one of copper and aluminum.

3. The multilayer electrode sheet according to claim 2, characterized in that, The metallic material includes at least one of lithium, aluminum, tin, and sodium; And / or, the non-metallic material includes at least one of silicon and carbon.

4. The multilayer electrode sheet according to any one of claims 1 to 3, characterized in that, The thickness of the substrate is 2μm to 20μm; And / or, the thickness of the functional layer is 0.5 μm to 50 μm.

5. The multilayer electrode sheet according to any one of claims 1 to 3, characterized in that, Including at least one of the following: Cu-Li multilayer electrode, Cu-Al multilayer electrode, Cu-Sn multilayer electrode, Al-Na multilayer electrode, Cu-Si multilayer electrode, Cu-C multilayer electrode, SUS-C multilayer electrode, Al-C multilayer electrode, Cu-Li-C multilayer electrode, Cu-Al-C multilayer electrode, PP-Cu-Li multilayer electrode, and PI-Cu-Li multilayer electrode.

6. The multilayer electrode sheet according to claim 5, characterized in that, The multilayer electrode is at least one of Al-Na multilayer electrode, Al-C multilayer electrode, Cu-Li-C multilayer electrode, Cu-Al-C multilayer electrode, and PP-Cu-Li multilayer electrode.

7. A method for preparing a multilayer electrode, characterized in that, include: At least one coating layer is sputtered as a functional layer on the surface of the substrate using vacuum magnetron sputtering to prepare the multilayer electrode sheet as described in any one of claims 1 to 6.

8. The method for preparing multilayer electrodes according to claim 7, characterized in that, In the vacuum magnetron sputtering method, the control parameters include any one of the following (1) to (3): (1) Voltage: 1000V~5000V; (2) Vacuum degree: 4×10 -3 Below Pa; (3) The magnetic control speed is 5m / min to 8m / min.

9. The method for preparing multilayer electrodes according to claim 7 or 8, characterized in that, In the vacuum magnetron sputtering method, the control parameters include any one of the following (1) to (3): (1) Voltage: 1200V~1400V; (2) Vacuum degree: 3×10 -3 Pa~4×10 -3 Pa; (3) The magnetic control speed is 6m / min to 7m / min.

10. A battery, characterized in that, It includes the multilayer electrode sheet according to any one of claims 1 to 6, or the multilayer electrode sheet obtained by the preparation method according to any one of claims 7 to 9.

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