Copper-graphene multilayer composite material coated copper foil for anode current collector

Abstract

Aspects of the present disclosure include copper-graphene (Cu-Gr) multilayer composite (CGMC) current collectors and methods of making the same. An example vehicle includes an electric motor and a battery pack electrically coupled to the electric motor. A battery pack includes a battery cell having a cell pouch with a plurality of stacked anode current collectors alternating with a plurality of stacked cathode current collectors therein and an active material dispersed within the cell pouch to cover the current collectors. Each anode current collector is a CGMC current collector including a copper foil substrate having a top surface and a bottom surface. The copper foil substrate is pure copper. The graphene layer is directly on at least one of the top surface and the bottom surface of the copper foil substrate, and the copper plating layer is directly on the graphene layer.

Description

Technical Field

[0001] The present disclosure relates to battery cell manufacturing, and in particular to a copper-graphene (Cu-Gr) multilayer composite (CGMC) coated copper foil for an anode current collector. Background Art

[0002] Electrodes are widely used in a range of devices for storing electrical energy, including primary (non-rechargeable) battery cells, secondary (rechargeable) battery cells, fuel cells, and capacitors. An ideal electrode needs to balance various electrical energy storage properties, such as energy density, power density, maximum charge rate, internal leakage current, equivalent series resistance (ESR), charge-discharge cycle durability, high conductivity, and low tortuosity. Electrodes typically include current collectors to supplement or otherwise improve these electrical energy storage properties. Current collectors can be added to provide higher specific conductance, and the available contact area can be increased to minimize the interfacial contact resistance between the electrode and its terminals.

[0003] The current collector is generally a sheet of conductive material to which the active electrode material is attached. Aluminum foil, stainless steel, and titanium foil are commonly used as current collectors for electrodes. In some electrode manufacturing processes, for example, a film comprising activated carbon powder (i.e., active electrode material) is attached to a thin aluminum foil using an adhesive layer. In order to improve the quality of the interfacial bonding between the active electrode material film and the current collector, the combination of the film and the current collector is processed in a pressure laminating machine (e.g., a calender). This method is generally referred to as calendering. Therefore, the manufacture of an electrode generally involves the production of an active electrode material film and laminating the film to a current collector. Summary of the invention

[0004] In an exemplary embodiment, a vehicle includes an electric motor and a battery pack electrically connected to the electric motor. The battery pack includes a battery cell having a cell bag and an active material, wherein the cell bag has a plurality of stacked anode current collectors alternating with a plurality of stacked cathode current collectors, and the active material is dispersed in the cell bag to cover the current collector. Each anode current collector is a copper-graphene (Cu-Gr) multilayer composite material (CGMC) current collector, which includes a copper foil substrate having a top surface and a bottom surface. The copper foil substrate is pure copper. The graphene layer is directly on at least one of the top surface and the bottom surface of the copper foil substrate, and the copper plating layer is directly on the graphene layer.

[0005] In addition to one or more features described herein, in some embodiments, the anode current collector also includes a first stack of multiple graphene layers alternating with multiple copper-plated layers on the top surface of the copper foil substrate and a second stack of multiple graphene layers alternating with multiple copper-plated layers on the bottom surface of the copper foil substrate.

[0006] In some embodiments, the first stack of a plurality of graphene layers alternating with a plurality of copper plated layers includes at least three graphene layers and at least three copper plated layers.

[0007] In some embodiments, each graphene layer has a first thickness, and each copper-plated layer has a second thickness greater than the first thickness. In some embodiments, the first thickness of each graphene layer is less than 1 nanometer. In some embodiments, the second thickness of each of the copper-plated layers is between 1 nanometer and 40 nanometers. In some embodiments, the second thickness of each copper-plated layer is substantially equal.

[0008] In another exemplary embodiment, the CGMC current collector includes a copper foil substrate having a top surface and a bottom surface. The copper foil substrate is pure copper. The graphene layer is directly on at least one of the top surface and the bottom surface of the copper foil substrate, and the copper plating layer is directly on the graphene layer.

[0009] In some embodiments, the anode current collector further comprises a first stack of multiple graphene layers alternating with multiple copper-plated layers on the top surface of the copper foil substrate and a second stack of multiple graphene layers alternating with multiple copper-plated layers on the bottom surface of the copper foil substrate.

[0010] In some embodiments, the first stack of a plurality of graphene layers alternating with a plurality of copper plated layers includes at least three graphene layers and at least three copper plated layers.

[0011] In some embodiments, each graphene layer has a first thickness, and each copper-plated layer has a second thickness greater than the first thickness. In some embodiments, the first thickness of each graphene layer is less than 1 nanometer. In some embodiments, the second thickness of each of the copper-plated layers is between 1 nanometer and 40 nanometers. In some embodiments, the second thickness of each copper-plated layer is substantially equal.

[0012] In yet another exemplary embodiment, a roll-to-roll manufacturing process for a CGMC current collector may include providing a copper foil substrate having a top surface and a bottom surface. The copper foil substrate is a pure copper foil substrate. The method may include directly forming a graphene layer on at least one of the top surface and the bottom surface of the copper foil substrate, and depositing a copper plating layer directly on the graphene layer.

[0013] In some embodiments, forming the graphene layer includes subjecting the copper foil substrate to a furnace unit at a furnace temperature of 500 to 1000 degrees Celsius. In some embodiments, the furnace unit is configured to deposit the graphene layer onto the copper foil substrate using a chemical vapor deposition (CVD) deposition process. In some embodiments, the graphene layer is deposited in a high vacuum chamber using a CVD deposition process.

[0014] In some embodiments, depositing the copper layer comprises subjecting the copper foil substrate coated with the graphene layer to a plating unit configured with an anode, a cathode, and a copper source. In some embodiments, the copper layer is plated in an environmentally controlled high vacuum chamber without breaking the vacuum from the furnace unit.

[0015] In some embodiments, the furnace unit and the plating unit are repeated as needed to form a first stack of multiple graphene layers alternating with multiple copper-plated layers on the top surface of the copper foil substrate, and a second stack of multiple graphene layers alternating with multiple copper-plated layers on the bottom surface of the copper foil substrate.

[0016] The above features and advantages and other features and advantages of the present disclosure are apparent from the following detailed description when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Other features, advantages, and details appear, by way of example only, from the following detailed description, which refers to the accompanying drawings.

[0018] Figure 1 is a vehicle configured according to one or more embodiments;

[0019] Figure 2A is an example battery cell according to one or more embodiments;

[0020] Figure 2B According to one or more embodiments Figure 2A A detailed view of an example battery cell shown in;

[0021] Figure 2C According to one or more embodiments Figure 2B A detailed view of one of the anode current collectors shown in;

[0022] Figure 3A is an exemplary roll-to-roll manufacturing process of a copper foil coated with a copper-graphene (Cu-Gr) multilayer composite (CGMC) according to one or more embodiments;

[0023] Figure 3B According to one or more embodiments Figure 3A A view of a copper foil substrate at a source unit of a roll-to-roll manufacturing process shown in FIG.

[0024] Figure 3C According to one or more embodiments Figure 3A A view of a copper foil substrate after deposition of a graphene layer at a furnace unit of a roll-to-roll manufacturing process shown in FIG.

[0025] Figure 3D According to one or more embodiments Figure 3A A view of a copper foil substrate after a copper plating layer is deposited at a plating unit of a roll-to-roll manufacturing process is shown;

[0026] Figure 3E is according to one or more embodiments in a repeated Figure 3AA view of a copper foil substrate after a furnace unit and a plating unit of a roll-to-roll manufacturing process as shown in FIG.

[0027] Figure 4 is a flow chart according to one or more embodiments. DETAILED DESCRIPTION

[0028] The following description is merely exemplary in nature and is not intended to limit the present disclosure, its application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate the same or corresponding parts and features.

[0029] Electrodes typically include current collectors to supplement or otherwise improve the electrical energy storage characteristics of the final integrated device (e.g., battery). The current collector typically includes a sheet of conductive material (e.g., aluminum foil) to which the active electrode material is attached. An energy storage system such as a battery cell or bag may include a plurality of stacked anode current collectors and cathode current collectors, active materials dispersed or otherwise located on the current collectors, and a sufficient number of separators to prevent short circuits between the anode current collector and the cathode current collector.

[0030] Copper is often chosen as the material for the anode current collector due to a number of desirable properties. One of the key advantages of copper is its relatively high electrical conductivity, which facilitates efficient electron transport within the electrode, providing high performance and enabling rapid charge / discharge cycles. Copper also provides excellent thermal conductivity, facilitating efficient dissipation of heat generated during battery operation, an essential feature for maintaining the stability and life of the battery cell, especially in high power applications.

[0031] The demand for energy storage systems that offer higher energy density, faster charging, and extended operating life, driven in part by the proliferation of electric vehicles, poses significant challenges to the materials used in battery cell components, particularly current collectors. Copper, popularly chosen for its excellent electrical conductivity and thermal properties, faces intense scrutiny in this context. Research and development efforts continue to be devoted to identifying new materials and manufacturing techniques that can meet the growing demands on battery cells and other energy storage systems.

[0032] The present disclosure introduces a new copper-graphene (Cu-Gr) multilayer composite (CGMC) coated copper foil anode current collector and a method for making the same. The anode current collector described herein does not rely solely on pure copper, but includes multiple graphenes and copper-plated layers formed on the underlying copper foil. In some embodiments, any number of alternating graphene and copper-plated layers are constructed on the copper foil using an arbitrarily repeatable roll-to-roll graphene deposition and copper plating process. The result is that the CGMC-coated copper foil has an electrical conductivity higher than 120% IACS (conductivity of annealed copper at 20 degrees Celsius according to the International Annealed Copper Standard), and the final device (e.g., a lithium battery) has improved electron transport, enhanced heat dissipation, and increased capacity compared to a device with a current collector made only of pure copper.

[0033] Utilizing CGMC-coated copper foil for anode current collectors manufactured in accordance with one or more embodiments provides several technical advantages over existing current collector specifications. Notably, the manufacturing process described herein can be used to produce electrodes and current collectors with any number of desired graphene and copper plating levels in a manner compatible with the pouch and cylindrical battery cell designs themselves, subject only to design requirements. Other advantages are possible. For example, the copper plating process described herein can be implemented in a continuous roll-to-roll process within an environmentally controlled vacuum chamber to greatly improve high-volume manufacturability (scaling) compared to what is possible using other techniques, such as electron beam deposition (EBD).

[0034] According to an exemplary embodiment, the vehicle Figure 1 1. The vehicle 100 is shown generally at 100. The vehicle 100 is shown in the form of an automobile having a body 102. The body 102 includes a passenger compartment 104, within which a steering wheel, front seats, and rear passenger seats (not shown separately) are arranged. A plurality of components are arranged within the body 102, including, for example, an electric motor 106 (shown by a projection under the front hood). The electric motor 106 is shown only for ease of illustration and discussion. It should be understood that the configuration, location, size, arrangement, etc. of the electric motor 106 are not meant to be particularly limited, and all such configurations (including multi-motor configurations) are within the intended scope of the present disclosure.

[0035] The electric motor 106 is powered via a battery pack 108 (shown by a projection near the rear of the vehicle 100). The battery pack 108 is shown for ease of illustration and discussion only. It should be understood that the configuration, location, size, arrangement, etc. of the battery pack 108 is not meant to be particularly limited, and all such configurations (including split configurations) are within the intended scope of the present disclosure. In addition, while the present disclosure is primarily discussed in the context of a battery pack 108 configured for an electric motor 106 of the vehicle 100, the aspects described herein may be similarly incorporated within any system (vehicle, building, or other) having an energy storage system (e.g., one or more battery packs or modules), and all such configurations and applications are within the intended scope of the present disclosure.

[0036] As will be described in detail herein, the battery pack 108 includes one or more battery cells and / or battery pouches having one or more CGMC-coated copper foil anode current collectors. Figure 2C An exemplary CGMC-coated copper foil anode current collector is shown in FIG. An exemplary manufacturing process of the CGMC-coated copper foil is shown in FIG. Figure 3A shown.

[0037] Figure 2A An example battery cell 202 is shown according to one or more embodiments. The battery cell 202 can be used as a battery pack (e.g., Figure 1 One of the multiple battery cells in the battery pack 108) is incorporated. Figure 2B According to one or more embodiments, Figure 2A Detailed view 204 of an example battery cell 202 is shown in FIG. Figure 2B As shown, the battery cell 202 includes a cell bag 206 having a plurality of stacked anode current collectors 208 and cathode current collectors 210. In some embodiments, the anode current collectors 208 and cathode current collectors 210 are alternated within the cell bag 206. The battery cell 202 also includes a separator 212 located between the anode current collector 208 and the cathode current collector 210 and an active material 214 dispersed within the cell bag 206 to cover the anode current collector 208 and the cathode current collector 210. The number of anode current collectors 208, cathode current collectors 210 and separators 212 and the amount of active material 214 are selected only for ease of discussion and convenience. It should be understood that the battery cell 202 can include any number of layers (e.g., anode layers and cathode layers) and a corresponding number of separators and any amount of active material as desired, and all of these configurations are within the intended scope of the present disclosure.

[0038] Anode current collector 208 and cathode current collector 210 can be made of conductive metal sheets or foils. For example, cathode current collector 210 can be made of aluminum foil, stainless steel, and / or titanium foil, to which active material 214 is attached. Other materials are possible, such as semi-metals (e.g., tin, graphite) and alloys of metals and / or their semi-metals. In some embodiments, cathode current collector 210 is made of aluminum foil. Anode current collector 208 may include copper foil coated with CGMC, and about Figure 2C Discuss in more detail.

[0039] The separator 212 may include a dielectric material such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), and composites thereof, although other dielectrics are also within the contemplated scope of the present disclosure.

[0040] The active material 214 is not meant to be particularly limited, but may include, for example, various cathode or anode materials (depending on the requirements of the specific application), such as activated carbon powder, nickel manganese cobalt oxide (NMC), lithium iron phosphate (LFP), nickel cobalt aluminum oxide (NCA), nickel cobalt manganese aluminum oxide (NC MA), lithium manganese iron phosphate (LMFP), lithium rich manganese (LMR), lithium manganese oxide (LMO), graphite, silicon, silicon-graphite composites, tin, tin oxide (SnO 2 ), lithium titanate (Li 4 Ti 5 O 12 , LTO), sulfur and lithium-sulfur (Li-S) composites, lithium metal (Li) and / or lithium alloys such as lithium-antimony (Li-Sb), lithium-aluminum (Li-Al) and lithium-germanium (Li-Ge).

[0041] In some embodiments, the anode current collectors 208 terminate together at a lead tab 216 (also referred to as a bus bar). In some embodiments, the lead tab 216 is made of the same or similar material as the anode current collectors 208. For example, in some embodiments, the lead tab 216 is a copper foil. In some embodiments, the lead tab 216 is a CGMC-coated copper foil. Although not shown separately, the cathode current collectors 210 may also terminate together at a (separate) lead tab and / or bus bar (omitted for clarity).

[0042] As previously described, the anode current collector 208 may include a CGMC-coated copper foil. Figure 2C According to one or more embodiments, Figure 2B A detailed view 218 of one of the anode current collectors 208 is shown in FIG. Figure 2C As shown, the anode current collector 208 may include a copper foil substrate 220 .

[0043] In some embodiments, an alternating stack of graphene layers 222 and copper-plated layers 224 is formed over a top surface 226 and / or a bottom surface 228 of a copper foil substrate 220. Figure 3A An example manufacturing process for forming the alternating stack of graphene layers 222 and copper-plated layers 224 is discussed in more detail.

[0044] In some embodiments, each of the graphene layers 222 is formed to a thickness less than or equal to 1 nanometer. In some embodiments, the graphene layers 222 can be formed to a thickness of several angstroms, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 angstroms. In some embodiments, the graphene layers 222 can be formed to a thickness between 1 angstrom and 4 angstroms.

[0045] In some embodiments, each of the electroplated copper layers 224 is formed to a thickness between 1 nanometer and several tens of nanometers. For example, the electroplated copper layer 224 can be formed to a thickness of 1 to 40 nanometers, 1 to 20 nanometers, 1 to 10 nanometers, and 1 to 5 nanometers. In some embodiments, each of the electroplated copper layers 224 is formed to substantially the same thickness (i.e., the same thickness within tool limitations, for example, within 1%, 3%, 5% of the nominal thickness).

[0046] The anode current collector 208 may include a copper foil substrate 220 and any number of alternating graphene layers 222 and copper-plated layers 224. For example, Figure 2C The anode current collector 208 shown in the figure includes a copper foil substrate 220 and an alternating stack of three graphene layers 222 and three copper-plated layers 224. Other configurations with different numbers of alternating graphene layers 222 and copper-plated layers 224 (e.g., 1 layer, 2, 4, 5, 6, 8, 10, 15, 20, 50 layers, etc.) are possible, and all such configurations are within the intended scope of the present disclosure. In addition, for convenience, Figure 2C The anode current collector 208 shown in FIG. 1 depicts a double-sided configuration (i.e., alternating graphene layers 222 and copper-plated layers 224 are formed on the top surface 226 and the bottom surface 228 of the copper foil substrate 220). Other configurations (e.g., single-sided configurations from either but not both of the top surface 226 and the bottom surface 228) are possible, and all such configurations are within the intended scope of the present disclosure.

[0047] Figure 3A An exemplary roll-to-roll manufacturing process 300 for coating copper foil with CGMC according to one or more embodiments is shown. Figure 3AAs shown, the roll-to-roll manufacturing process 300 includes a source unit 302, an oven unit 304, a dryer unit 306, a plating unit 308, and a collection unit 310, which are arranged in the order shown. In some embodiments, a sequence of positioning rollers 312 guides the copper foil substrate 220 along the roll-to-roll manufacturing process 300 (i.e., from one unit to another unit throughout the sequence).

[0048] In some embodiments, the roll-to-roll manufacturing process 300 begins at a source unit 302, where a copper foil substrate 220 (see Figure 2C ) is placed on or otherwise supplied to the input roller 314. In some embodiments, the copper foil substrate 220 is a copper foil wound into a roll, which is placed on the input roller 314. In some embodiments, the copper foil substrate 220 is fed to the roll-to-roll manufacturing process 300 (e.g., the input roller 314) as a continuous copper foil sheet (not separately shown).

[0049] In some embodiments, positioning rollers 312 move or otherwise direct the copper foil substrate 220 from the source unit 302 to the oven unit 304 . Figure 3B A view of the copper foil substrate 220 is depicted as it leaves the source unit 302 .

[0050] In some embodiments, furnace unit 304 deposits graphene layer 222 onto copper foil substrate 220 using a chemical vapor deposition (CVD) process. In some embodiments, graphene layer 222 is deposited using CVD deposition in a high vacuum chamber. As used herein, a "high vacuum" chamber refers to a controlled environment chamber in which air and other gases are removed to produce 10 -3 Up to 10 -8 For example, a high vacuum chamber can be operated at a vacuum in the torr range of less than 10 -6 In some embodiments, the graphene layer 222 is deposited using CVD deposition at a furnace temperature of 500 to 1000 degrees Celsius. In some embodiments, the graphene layer 222 is deposited using a CVD deposition chemistry including methane, hydrogen, and argon. In some embodiments, the graphene layer 222 is deposited to a thickness of less than or equal to 1 nanometer. In some embodiments, the graphene layer 222 can be formed to a thickness between 1 angstrom and 4 angstroms.

[0051] In some embodiments, positioning rollers 312 move or otherwise direct the copper foil substrate 220 from the oven unit 304 to the dryer unit 306 . Figure 3C is a view of the copper foil substrate 220 after deposition of the graphene layer 222 before moving to the dryer unit 306 .

[0052] In some embodiments, the dryer unit 306 dries and / or cools the copper foil substrate 220 to fix the deposited graphene layer 222 to the surface of the copper foil substrate 220. In some embodiments, cooling and drying are performed in a transition vacuum chamber. In some embodiments, the transition vacuum chamber is in the same vacuum (e.g., high vacuum) as the furnace unit 304. In some embodiments, the graphene layer 222 is cooled at a temperature below 300 degrees Celsius. Although it is not intended to be particularly limited, cooling can be achieved by methods such as forced air cooling, liquid cooling, and / or contact cooling using, for example, a pre-cooled surface. In some embodiments, the graphene layer 222 is dried by techniques such as vacuum drying, heat-assisted drying, and / or by using an inert carrier gas. Drying can be used to achieve desired material properties and evaporate residual liquids, such as solvents or liquids used to synthesize the graphene layer 222 and transfer the graphene layer 222 to the copper foil substrate 220.

[0053] In some embodiments, positioning rollers 312 move or otherwise direct the copper foil substrate 220 from the dryer unit 306 to the plating unit 308 .

[0054] In some embodiments, the plating unit 308 utilizes an anode 316 and a cathode 318 to plate the exposed surface of the graphene layer 222 with a copper-plated layer 224. In some embodiments, the anode 316 is a copper source. In some embodiments, the copper-plated layer 224 is plated in an environmentally controlled high vacuum chamber, so that the connection with other vacuum chambers (reference furnace unit 304 and dryer unit 306) is simple and more robust to vacuum loss or leakage. In some embodiments, the copper-plated layer 224 is deposited to a thickness between 1 nanometer and tens of nanometers. For example, the copper-plated layer 224 can be deposited to a thickness of 1 to 40 nanometers, 1 to 20 nanometers, 1 to 10 nanometers, and 1 to 5 nanometers. In some embodiments, each of the electroplated copper layers 224 is formed to substantially the same thickness (i.e., the same thickness within the tool limit, for example, within 1%, 3%, 5% of the nominal thickness). Figure 3D is a view of the copper foil substrate 220 after the copper plating layer 224 is deposited.

[0055] In some embodiments, positioning rollers 312 move or otherwise direct the copper foil substrate 220 from the electroplating unit 308 to the collection unit 310 .

[0056] In some embodiments, the collecting unit 310 includes a collecting roller 320 (also referred to as a rewinding roller) configured to recover the copper foil substrate 220 after forming the graphene layer 222 and the copper plating layer 224. In some embodiments, the collecting roller 320 is configured to recover the copper foil substrate 220 after a single pass through the furnace unit 304 and the plating unit 308. In some embodiments, the collecting roller 320 is configured to recover the copper foil substrate 220 after multiple passes through the furnace unit 304 and the plating unit 308.

[0057] In some embodiments, a reverse roller scheme is relied upon to achieve multiple passes through the furnace unit 304 and the plating unit 308. In this configuration, one or more of the collection rollers 320 and / or any combination of the positioning rollers 312 are configured for forward and backward (reverse) positioning of the copper foil substrate 220. In some embodiments, after the copper foil substrate 220 completes the plating unit 308 (i.e., after forming the copper-plated layer 224), the collection roller 320 and / or any combination of the positioning rollers 312 are reversed in direction. In some embodiments, the copper foil substrate 220 is reversed back into the dryer unit 306 after completing the electroplating unit 308 to be cooled and / or dried before being finally reversed back into the furnace unit 304. Once back in the furnace unit 304, the roll-to-roll manufacturing process 300 can be repeated to form additional graphene and copper-plated layers.

[0058] In some embodiments, a take-out and replacement scheme is relied upon to achieve multiple passes through the furnace unit 304 and the plating unit 308. In this configuration, after the copper foil substrate 220 completes the plating unit 308 (i.e., after the copper plated layer 224 is formed), the copper foil substrate 220 is collected (via, for example, a take-up) and removed from the collection roll 320. In some embodiments, the copper foil substrate 220 coated with the graphene layer 222 and the copper plated layer 224 is then placed back onto the input roll 314, and the roll-to-roll manufacturing process 300 can be repeated as previously described to form additional graphene layers 222 and copper plated layers 224.

[0059] Regardless of the multi-pass method used, Figure 3E It's repeating Figure 3A 304 and the plating unit 308 of the roll-to-roll manufacturing process 300. In particular, Figure 3E The copper foil substrate 220 is shown after the furnace unit 304 and the plating unit 308 are repeated three times. However, it should be understood that the furnace unit 304 and the plating unit 308 can be repeated any number of times (1, 2, 3, 4, 5, 10, 20 times, etc.) as needed to produce a CGMC-coated copper foil having any number of graphene and plated copper layers, and all such configurations are within the intended scope of the present disclosure.

[0060] Reference now Figure 4, a flow chart 400 is generally shown for manufacturing a CGMC coated copper foil using a roll-to-roll manufacturing process according to one embodiment. Figure 1-3E Flowchart 400 is described and may include Figure 4 Although depicted in a particular order, Figure 4 The blocks depicted in the drawings may be rearranged, subdivided, and / or combined.

[0061] At block 402, the method includes providing a copper foil substrate having a top surface and a bottom surface. In some embodiments, the copper foil substrate is a pure copper foil substrate. As used herein, a "pure" copper foil substrate refers to a substantially pure copper foil with very few impurities, wherein the impurities are less than 3 weight % copper.

[0062] At block 404, the method includes forming a graphene layer directly on at least one of a top surface and a bottom surface of a copper foil substrate. In some embodiments, forming the graphene layer includes subjecting the copper foil substrate to a furnace unit at a furnace temperature of 500 to 1000 degrees Celsius. The furnace unit is configured to deposit the graphene layer onto the copper foil substrate using a CVD deposition process. In some embodiments, the graphene layer is deposited in a high vacuum chamber using a CVD deposition process.

[0063] At block 406, the method includes depositing a copper plated layer directly on the graphene layer. In some embodiments, depositing the copper plated layer includes subjecting the copper foil substrate coated with the graphene layer to a plating unit configured with an anode, a cathode, and a copper source. In some embodiments, the copper plated layer is plated in an environmentally controlled high vacuum chamber without breaking the vacuum from the furnace unit.

[0064] In some embodiments, each graphene layer has a first thickness and each copper-plated layer has a second thickness greater than the first thickness. In some embodiments, the first thickness of each graphene layer is less than 1 nanometer. In some embodiments, the second thickness of each of the copper-plated layers is between 1 nanometer and 40 nanometers. In some embodiments, the second thickness of each copper-plated layer is substantially equal (e.g., within tool limitations).

[0065] In some embodiments, the method includes repeating the furnace unit and the plating unit as many times as needed to form a first stack of multiple graphene layers alternating with multiple copper-plated layers on the top surface of the copper foil substrate, and a second stack of multiple graphene layers alternating with multiple copper-plated layers on the bottom surface of the copper foil substrate.

[0066] The terms "a" and "an" do not indicate a limitation of quantity, but rather indicate the presence of at least one of the referenced item. Unless the context clearly indicates otherwise, the term "or" means "and / or". References to "aspects" throughout the specification mean that a particular element (e.g., a feature, structure, step, or characteristic) described in conjunction with that aspect is included in at least one aspect described herein, and may or may not be present in other aspects. In addition, it should be understood that the described elements may be combined in any suitable manner in the various aspects.

[0067] When an element such as a layer, film, region, or substrate is referred to as being "on" another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements present.

[0068] Unless otherwise indicated herein, all test standards are the most current standards in effect as of the filing date of this application or, if priority is claimed, the filing date of the earliest priority application in which the test standards appear.

[0069] Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0070] Although the above disclosure has been described with reference to exemplary embodiments, it will be appreciated by those skilled in the art that various changes may be made and equivalents may be substituted for its elements without departing from its scope. In addition, many modifications may be made to adapt specific circumstances or materials to the teachings of the disclosure without departing from the basic scope of the disclosure. Therefore, it is intended that the disclosure is not limited to the specific embodiments disclosed, but will include all embodiments falling within its scope.

Claims

1. A vehicle comprising: Electric motor; as well as a battery pack electrically coupled to the motor, the battery pack comprising a battery cell, the battery cell comprising a cell pouch having a plurality of stacked anode current collectors alternating with a plurality of stacked cathode current collectors, and an active material dispersed within the cell pouch to cover the plurality of anode current collectors and the plurality of cathode current collectors; Each of the anode current collectors comprises a copper-graphene (Cu-Gr) multilayer composite (CGMC) current collector, and the copper-graphene (Cu-Gr) multilayer composite (CGMC) current collector comprises: a copper foil substrate having a top surface and a bottom surface, the copper foil substrate comprising pure copper; a graphene layer directly on at least one of the top surface and the bottom surface of the copper foil substrate; as well as The copper-plated layer is directly located on the graphene layer.

2. The vehicle of claim 1 , the anode current collector further comprising a first stack of a plurality of graphene layers alternating with a plurality of copper-plated layers on a top surface of the copper foil substrate and a second stack of a plurality of graphene layers alternating with a plurality of copper-plated layers on a bottom surface of the copper foil substrate. 3 . The vehicle of claim 2 , wherein the first stack of a plurality of graphene layers alternating with a plurality of copper-plated layers comprises at least three graphene layers and at least three copper-plated layers. 4 . The vehicle of claim 2 , wherein each graphene layer has a first thickness, and each copper plating layer has a second thickness greater than the first thickness. 5 . The vehicle of claim 4 , wherein the first thickness of each of the graphene layers is less than 1 nanometer. 6 . The vehicle of claim 4 , wherein the second thickness of each of the copper plating layers is between 1 nanometer and 40 nanometers. 7 . The vehicle of claim 4 , wherein the second thickness of each of the copper plating layers is substantially equal.

8. A copper-graphene (Cu-Gr) multilayer composite (CGMC) current collector, comprising: a copper foil substrate having a top surface and a bottom surface, the copper foil substrate comprising pure copper; a graphene layer directly on at least one of the top surface and the bottom surface of the copper foil substrate; as well as A copper layer is plated directly on the graphene layer.

9. The current collector of claim 8, further comprising a first stack of a plurality of graphene layers alternating with a plurality of copper-plated layers on the top surface of the copper foil substrate and a second stack of a plurality of graphene layers alternating with a plurality of copper-plated layers on the bottom surface of the copper foil substrate. 10 . The current collector of claim 9 , wherein the first stack of the plurality of graphene layers alternating with the plurality of copper plated layers comprises at least three graphene layers and at least three copper plated layers.

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