Web coating cooling drum with turbulators for high flux metallic lithium deposition

Abstract

The present disclosure relates to vapor deposition systems and methods. In one embodiment, a drum for vapor deposition is provided. The drum includes a shell with a gas slit and a cooling drum. The cooling drum includes an outer region, an inner region, a first fluid channel partially defined by the outer region and the inner region, and a first inlet. The first fluid channel forms a spiral channel around a central axis of the cooling drum. The first inlet is fluidly connected to a first outlet via the first fluid channel.

Description

[Technical Field]

[0001] FIELD OF THE INVENTION Implementations described herein relate generally to metal electrodes, and more particularly to high performance electrochemical devices, such as lithium-containing anodes, primary and secondary electrochemical devices, including the aforementioned lithium-containing electrodes, and methods of making the same. [Background technology]

[0002] Lithium (Li)-ion batteries have played a key role in the development of current generations of mobile devices, microelectronics, and electric vehicles. A typical Li-ion battery consists of a positive electrode (cathode), a negative electrode (anode), an electrolyte for ion conduction, a porous separator membrane (electrical insulator) to physically separate the two electrodes, and packaging.

[0003] The method of depositing lithium on substrates, such as large flexible substrates, is temperature sensitive and can result in wrinkles and other defects. The substrate is guided over and supported by a rotatable coating drum with a curved drum surface. Vapor can be deposited on the substrate while moving past one or more evaporation sources on the curved drum surface of the rotatable drum. The drum can be used to maintain a high heat transfer rate and control the temperature of the substrate by using high pressure to cool and pressurize the backside of the substrate and maintain a uniform gap height between the substrate and the curved surface of the drum. Low web tensions can be used with wide, thin film substrates due to particles, film stress, or misalignment that can cause machine direction wrinkles.

[0004] Therefore, there is a need for an apparatus and method that maintains low pressure and enhances cooling of the substrate to increase throughput. Summary of the Invention

[0005] The present disclosure relates to vapor deposition systems and methods. In one embodiment, a drum for vapor deposition is provided. The drum includes a shell having a gas slit and a cooling drum. The cooling drum includes an outer region, an inner region, a first fluid channel partially defined by the outer region and the inner region, and a first inlet. The first fluid channel forms a spiral channel around a central axis of the cooling drum. The first inlet is fluidly connected to a first outlet via the first fluid channel.

[0006] In one embodiment, a roll-to-roll deposition system is provided. The roll-to-roll deposition system includes an evaporation unit, multiple tension rollers, and a drum. The drum is disposed between the multiple tension rollers and the evaporator unit. The drum includes a shell having a gas slit and a cooling drum. The cooling drum includes an exterior region, an interior region, a first fluid channel, and a first inlet. The first fluid channel is partially defined by the exterior region and the interior region. The first fluid channel forms a spiral channel around a central axis of the cooling drum. The first fluid inlet is in communication with a first outlet by the first fluid channel.

[0007] In one embodiment, a method for applying an anode material to a substrate is provided. The method includes supplying a coolant to a drum. The drum includes a shell and a cooling drum disposed radially inward of the shell. The cooling drum has a first fluid channel. The first fluid channel is partially defined by an outer region of the cooling drum and an inner region of the cooling drum, and the first fluid channel forms a spiral channel around a central axis of the cooling drum. The method also includes flowing the coolant through the first fluid channel, flowing a gas through a cavity between the shell and the cooling drum, rolling the substrate on the shell, and evaporating the anode material onto the substrate.

[0008] So that the above features of the present disclosure can be understood in detail, a more particular description of the present disclosure, briefly summarized above, can be had by reference to embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the accompanying drawings depict only exemplary embodiments and therefore should not be considered limiting of the scope thereof, as other equally effective embodiments may be tolerated. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic cross-sectional view of one implementation of an energy storage device incorporating an anode electrode structure according to some embodiments described herein. [Figure 2] 1 is a cross-sectional view of one implementation of a double-sided anode electrode structure according to some embodiments described herein. [Figure 3] 1 is a schematic cross-sectional view of an evaporation source for depositing evaporation material on a substrate according to some embodiments described herein. [Figure 4A] 1 is a schematic diagram of a roll-to-roll unit incorporating a drum according to some embodiments described herein. [Figure 4B] 1 illustrates the internal shape of the channel region of the drum, according to some embodiments described herein. [Figure 4C] 1 is a schematic cross-sectional view of a drum according to some embodiments described herein. [Figure 5A] 1 is a schematic diagram of the interior of a fluid channel of a drum, according to some embodiments described herein. [Figure 5B] 5B is a schematic diagram of the interior of the fluid channel of FIG. 5A according to some embodiments described herein. [Figure 6] 1 is a flow diagram of a method for cooling a substrate while using a roll-to-roll deposition system incorporating a drum, according to some embodiments described herein. DETAILED DESCRIPTION OF THE INVENTION

[0010] For ease of understanding, wherever possible, like reference numerals are used to designate like elements common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

[0011] Vapor deposition systems for coating a web substrate guided over a rotatable coating drum are referred to herein as roll-to-roll (R2R) deposition systems. As used herein, flexible substrates are considered to include, among other things, films, foils, webs, strips, etc. of plastic materials, metals, paper, or other materials. Typically, terms such as "web," "foil," "strip," and "substrate" are used synonymously.

[0012] Energy storage devices, such as Li-ion batteries, typically include a positive electrode (e.g., cathode) and a negative electrode (e.g., anode) separated by a polymer separator with a liquid electrolyte. Solid-state batteries also typically include a positive electrode and a negative electrode, but both the polymer separator and the liquid electrolyte are replaced with ionically conductive materials. Lithium is deposited on a substrate by evaporating molten lithium and condensing the lithium vapor onto a substrate, such as a graphite-coated copper foil, copper foil, or copper-coated polymer film. While lithium is deposited on the front side of the substrate, the substrate is maintained below a certain temperature. Maintaining the temperature may include cooling the back side of the substrate by venting a gas between the drum surface supporting the substrate and the substrate. The deposition rate of lithium on the substrate is limited by the cooling rate of the back side of the substrate. The cooling gas is selected to be non-reactive with lithium. In some embodiments, the cooling gas may be or include argon, helium, or a combination thereof.

[0013] In addition to supplying cooling gas to the backside of the substrate, a uniform gap distance between the substrate and the drum surface is typically maintained. Traditional solutions for holding the substrate include high tension (e.g., greater than 100 Newtons per meter of web tension) and mechanical solutions, such as placing nip rollers around the drum to hold the substrate to the drum and prevent the substrate from flying off the drum due to the gas supply and thermal expansion of the substrate. These solutions can lead to web edge damage and coating delamination. It has been found that Coulomb electrostatic clamps can be used to hold the substrate to the drum and maintain a uniform gap between the substrate and the drum surface.

[0014] In some embodiments, the substrate is a flexible substrate supported on a curved drum surface of a rotatable drum during deposition, and specifically, the substrate can be moved on the curved drum surface of the rotatable drum past a number of nozzles that deposit material onto the substrate.

[0015] The substrate may be, for example, a flexible substrate such as a flexible polymer material or a flexible metal foil, more specifically, a copper foil or copper-carrying foil, e.g., a foil coated with copper on one or both sides. The substrate may have a thickness of 50 μm or less, particularly 20 μm or less, e.g., about 8 μm. In some embodiments, the substrate may be a thin copper foil having a thickness in the range of less than 20 μm (e.g., 4 micrometers thick, or 6 micrometers thick).

[0016] According to some embodiments, which can be combined with other embodiments described herein, a battery anode is produced, and the flexible substrate includes or consists of copper or a copper alloy. According to some implementations, the web can further include graphite, silicon, silicon oxide, or any combination thereof. For example, lithium can prelithiate a layer including graphite, silicon, and / or silicon oxide.

[0017] Depositing a metal, such as lithium, onto a flexible substrate, such as a copper substrate, by evaporation can be used to fabricate batteries, such as Li batteries. For example, a lithium layer can be deposited onto a thin flexible substrate to fabricate the anode of the battery. After assembly of the anode layer stack and the cathode layer stack, optionally with an electrolyte and / or separator sandwiched between them, the fabricated layer arrangement can be wound or otherwise stacked to fabricate a Li battery.

[0018] FIG. 1 shows a schematic cross-sectional view of one implementation of an energy storage device 100 incorporating an anode electrode structure 110 formed in accordance with implementations described herein. The anode electrode structure 110 includes an anode film 170 having one or more ceramic protective films formed thereon. The energy storage device 100 can be a solid-state energy storage device or a lithium-ion-based energy storage device. While the energy storage device 100 is shown as a planar structure, it can also be formed into a cylindrical shape by winding a stack of layers. Additionally, other cell configurations (e.g., prismatic cells, button cells, or stacked electrode cells) can also be formed. The energy storage device 100 includes an anode electrode structure 110 and a cathode electrode structure 120, optionally with an electrolyte or polymer separator 130 positioned therebetween. The cathode electrode structure 120 includes a cathode current collector 140 and a cathode film 150.

[0019] The one or more protective films 180 include one or more ceramic materials. The ceramic material can be an oxide, nitride, or a fluoride or carbonate that is soluble in the electrolyte. In one implementation, the one or more ceramic protective films 180 include, for example, aluminum oxide (Al2O3), lithium fluoride (LiF), lithium carbonate (Li2CO3), aluminum oxynitride, aluminum nitride (AlN, aluminum deposited in a nitrogen environment), aluminum oxide hydroxide ((AlO(OH)) (e.g., diaspore ((α-AlO(OH))), boehmite (γ-AlO(OH)), or accdalite (5Al2O3·H2O)), calcium carbonate (CaCO3), titanium dioxide (TiO2), sulfide (S), or aluminium oxynitride (AlO(OH)). The ceramic protective film 180 may comprise a material selected from iS2, SiPO4, silicon oxide (SiO2), zirconium oxide (ZrO2), hafnium oxide (HfO2), MgO, TiO2, Ta2O5, Nb2O5, LiAlO2, BaTiO3, boron nitride (BN), ion-conducting garnets, ion-conducting perovskites, ion-conducting antiperovskites, porous glass-ceramics, and the like, or combinations thereof. In certain implementations, the one or more ceramic protective films 180 are deposited using the evaporation techniques described herein.

[0020] In certain implementations, each layer of the one or more protective films 180 is a coating or individual film having a thickness in the range of about 1 nanometer to about 3,000 nanometers (e.g., in the range of about 10 nanometers to about 600 nanometers; in the range of about 50 nanometers to about 100 nanometers; in the range of about 50 nanometers to about 200 nanometers; in the range of about 100 nanometers to about 150 nanometers).

[0021] The cathode electrode structure 120 includes a cathode current collector 140 and a cathode film 150 formed on the cathode current collector 140. It is understood that the cathode electrode structure 120 may include other elements or films.

[0022] The current collectors 140, 160 on the cathode film 150 and the anode film 170 may be the same electronic conductor or different electronic conductors. In a specific implementation, at least one of the current collectors 140, 160 is a flexible substrate. The flexible substrate may be a CPP film (i.e., a cast polypropylene film), an OPP film (i.e., an oriented polypropylene film), or a PET film (i.e., a polyethylene terephthalate film). Alternatively, the flexible substrate may be precoated paper, a polypropylene (PP) film, a PEN film, a polylactic acid (PLA) film, or a PVC film. Examples of metals that may constitute the current collectors 140, 160 include aluminum (Al), copper (Cu), zinc (Zn), nickel (Ni), cobalt (Co), manganese (Mn), chromium (Cr), stainless steel, clad materials, alloys thereof, and combinations thereof. In one implementation, at least one of the current collectors 140, 160 is perforated. In one implementation, at least one of the current collectors 140, 160 comprises a polymer substrate (e.g., polyethylene terephthalate (“PET”)) coated with a metallic material. In one implementation, the anode current collector 160 is a polymer substrate (e.g., a PET film) coated with copper. In another implementation, the anode current collector 160 is a multi-metal layer on a polymer substrate. The multi-metal layer can be a combination, such as copper, chromium, nickel, alloys thereof, or any combination thereof. In one implementation, the anode current collector 160 is a copper-nickel The anode current collector 160 is a multilayer structure including a Kelclad material. In one implementation, the multilayer structure includes a first layer of nickel or chromium, a second layer of copper formed on the first layer, and a third layer including nickel, chromium, or both formed on the second layer. In one implementation, the anode current collector 160 is nickel-coated copper. In one implementation, the anode current collector 160 is graphite-coated copper. Furthermore, the current collector can be of any form factor (e.g., metal foil, sheet, or plate), shape, and micro / macro structure.

[0023] In one implementation, the cathode current collector 140 is aluminum. In another implementation, the cathode current collector 140 can be or include aluminum deposited on a polymer substrate (e.g., a PET film). The cathode current collector 140 can have a thickness of less than 50 μm, more specifically less than 5 μm, or even more specifically 2 μm. The cathode current collector 140 can have a thickness of about 0.5 μm to about 20 μm (e.g., about 1 μm to about 10 μm; about 2 μm to about 8 μm; or about 5 μm to about 10 μm). In one implementation, the anode current collector 160 is copper. In one implementation, the anode current collector 160 is stainless steel. In one implementation, the anode current collector 160 has a thickness of less than 50 μm, more specifically less than or equal to about 5 μm, or even more specifically less than or equal to about 2 μm. In one implementation, the anode current collector 160 has a thickness of about 0.5 μm to about 20 μm (e.g., about 1 μm to about 10 μm; about 2 μm to about 8 μm; about 6 μm to about 12 μm; or about 5 μm to about 10 μm).

[0024] The cathode film 150, or cathode, can be any material compatible with the anode and can include intercalation compounds, insertion compounds, or electrochemically active polymers.

[0025] The anode electrode structure 110 includes an anode current collector 160 having an anode film 170 formed on the anode current collector 160. The anode electrode structure 110 includes one or more ceramic protective films 180.

[0026] In some implementations, the anode film 170 is composed of lithium metal, lithium metal foil, or a lithium alloy foil (e.g., lithium aluminum alloy or lithium tin alloy), or a mixture of lithium metal and / or lithium alloys and materials, such as carbon (e.g., coke, graphite), nickel, copper, tin, indium, silicon, mixtures thereof, or any combination thereof. The anode film 170 can be or include one or more lithium-containing intercalation compounds or lithium-containing insertion compounds. In certain implementations, the anode film is a lithium metal film. In certain implementations in which the anode film 170 can be or include lithium metal, the lithium metal can be deposited using methods described herein.

[0027] In some implementations, the anode film 170 can be or include graphite, silicon, or any combination thereof. The anode film 170 can be or include one or more carbonaceous materials, such as natural or artificial graphite, partially graphitized or amorphous carbon, petroleum, coke, needle coke, and various mesophases, silicon-containing graphite, silicon, nickel, copper, tin, indium, aluminum, silicon, mixtures thereof, combinations thereof, or mixtures of lithium metal and / or lithium alloys with materials such as carbon (e.g., coke or graphite), nickel, copper, tin, indium, aluminum, silicon, mixtures thereof, or combinations thereof. In one example, the anode film 170 can be or include silicon-graphite. In another example, the anode film 170 can be or include graphite.

[0028] In some implementations, in which the anode film 170 can be or can include graphite, silicon, or silicon-graphite, the anode film 170 has a layer of lithium formed on the surface of the anode film 170. The lithium metal layer can have a thickness of about 20 μm to about 50 μm. The lithium layer can be a prelithiated layer.

[0029] In one implementation, the anode film 170 has a thickness of about 10 μm to about 200 μm (e.g., about 1 μm to about 100 μm; about 10 μm to about 30 μm; about 20 μm to about 30 μm; about 1 μm to about 20 μm; or about 50 μm to about 100 μm).

[0030] In some embodiments, the polymer separator 130 is a separator that is a porous polymer ion-conducting polymer substrate. In one implementation, the porous polymer substrate is a multilayer polymer substrate. In certain implementations, the porous polymer substrate has a porosity in the range of about 20% to about 80% (e.g., in the range of about 28% to about 60%). The porous polymer substrate can have an average pore size in the range of about 0.02 μm to about 5 μm (e.g., about 0.08 μm to about 2 μm). In certain implementations, the porous polymer substrate has a Gurley number in the range of about 15 seconds to about 150 seconds. The porous polymer substrate can be or can include one or more polyolefin polymers. Examples of suitable polyolefin polymers include polypropylene, polyethylene, or a combination thereof. In at least one aspect, the porous polymer substrate is a polyolefin membrane. In some aspects, the polyolefin membrane is a polyethylene membrane or a polypropylene membrane.

[0031] 2 shows a cross-sectional view of one implementation of a double-sided anode electrode structure 210 formed in accordance with one or more implementations described herein. The double-sided anode electrode structure 210 includes an anode current collector 160 and anode films 170a, 170b (collectively 170) formed on both sides of the anode current collector 160. The double-sided anode electrode structure 210 further includes one or more protective films 180a, 180b (collectively 180) formed on the anode films 170a, 170b, respectively.

[0032] FIG. 3 is a schematic cross-sectional view of a vapor deposition apparatus 300 incorporating a drum 310. The vapor deposition apparatus 300 can be a roll-to-roll deposition system for coating flexible substrates, such as foils or polymer substrates. The substrate to be coated can have a thickness of 50 μm or less, particularly 20 μm or less, or even 6 μm or less. For example, a metal foil or a flexible metal-coated foil can be coated in the vapor deposition apparatus. In some implementations, the substrate 301 is a thin copper foil or a thin aluminum foil having a thickness of less than 30 μm, for example, 6 μm or less. The substrate can also be a thin metal foil (e.g., copper foil) coated with graphite, silicon, silicon oxide, or any combination thereof, and can have a thickness of, for example, 150 μm or less, particularly 100 μm or less, or even 50 μm or less. According to some implementations, the web can further include graphite, silicon, silicon oxide, or any combination thereof. For example, lithium can prelithiate a layer comprising graphite, silicon, silicon oxide, or any combination thereof.

[0033] In a roll-to-roll deposition system, the substrate 301 can be unwound from a storage spool and at least one or more layers of material can be deposited onto the substrate while the substrate 301 is guided over a drum 310.

[0034] The drum 310 has a curved surface 303 of the drum 310, a central axis A1, a first surface 311, and a second surface 309 opposite to the first surface 311. The drum 310 is rotatable about the central axis A1.

[0035] The vapor deposition apparatus 300 includes an evaporation unit 350 for depositing an evaporation material on a substrate 301 according to embodiments described herein. The evaporation unit 350 includes an evaporation crucible 330 for heating a solid or liquid source material 312 to a temperature higher than the evaporation or sublimation temperature of the source material 312 to evaporate the source material 312. The evaporation crucible 330 may include an interior volume that serves as a material reservoir for containing the source material 312 in a solid and / or liquid state, and a first heater 335 for heating the interior volume of the evaporation crucible to evaporate the source material 312. For example, the source material 312 may be a metal, particularly lithium, and the first heater 335 may be configured to heat the interior volume of the crucible to a temperature of about 180° C. or higher, particularly about 215° C. or higher, or about 400° C. or higher.

[0036] The evaporation unit 350 further includes a vapor distributor 320 with a plurality of nozzles 321 for directing the evaporated material in the evaporation crucible toward the substrate 301, thereby depositing a coating on the substrate 301. The vapor distributor 320 can have an interior volume in fluid communication with the interior volume of the evaporation crucible 330, such that the evaporated material can flow from the interior volume of the evaporation crucible 330 through the vapor conduit 340 into the interior volume of the vapor distributor 320 along, for example, a linear connecting pipe or passageway. The plurality of nozzles 321 can be configured to direct the evaporated material from the interior volume of the vapor distributor 320 toward the substrate 301.

[0037] In some embodiments, the vapor distributor 320 can be a vapor distribution showerhead having multiple nozzles arranged in a one- or two-dimensional pattern to direct the evaporated material toward the substrate.

[0038] The evaporation crucible 330 is fluidly connected to the vapor distributor 320 via a vapor conduit 340 that extends from the evaporation crucible 330 to the vapor distributor 320 in a conduit length direction A. During evaporation, the vapor distributor 320 is typically set to a second temperature higher than the first temperature in the evaporation crucible 330 to prevent condensation of material on the interior walls of the vapor distributor.

[0039] The evaporation unit 350 may further include a second heater 325 for heating the internal volume of the vapor distributor. The first heater 335 and the second heater 325 are independently controllable. For example, the first heater 335 may be configured to heat the evaporation crucible to a first temperature, and the second heater 325 may be configured to heat the vapor distributor to a second temperature different from the first temperature, particularly a temperature higher than the first temperature. During vapor deposition, the internal volume of the vapor distributor is typically heated to a temperature higher than the internal volume of the evaporation crucible to prevent the evaporation material from condensing on the internal wall of the vapor distributor. Meanwhile, most of the internal volume of the evaporation crucible is maintained near the evaporation temperature of the source material 312 (i.e., slightly lower or slightly higher than the evaporation temperature) so that the source material 312 can gradually evaporate at a predetermined evaporation rate.

[0040] In some embodiments, which can be combined with other embodiments described herein, the multiple nozzles 321 are arranged in multiple nozzle rows extending in a row direction L and arranged adjacent to one another in a circumferential direction T, where the row direction L can essentially correspond to the axial direction of the drum 310. Thus, the vapor distributor 320 provides an area showerhead having multiple nozzles arranged in a two-dimensional array to reduce the heat load per area on the substrate 301 supported on the curved surface 303.

[0041] The substrate 301 is held on the curved surface 303 using electrostatic clamping high voltage electrodes and a dielectric coating integrated into the drum 310. Depending on the type or material of the substrate, the electrostatic clamping electrodes and the dielectric coating can be integrated into the drum 310 in a variety of implementations.

[0042] 4A shows a schematic view of a roll-to-roll unit 400 viewed along the central axis A1 of the drum 310 according to an embodiment of the present disclosure. The roll-to-roll unit 400 may include an evaporation unit or multiple evaporation sources according to any of the embodiments described herein, such as the evaporation unit 350 described in connection with FIG.

[0043] The roll-to-roll unit 400 includes a substrate support, which is a curved surface 303 of a drum 310, for supporting the substrate 301 during deposition. The substrate 301 is fed from a supply reel 401 to the drum 310, where material 315 is deposited onto the substrate 301. Once deposited, the substrate 301 moves to an end reel 402, where the substrate 301 is wound onto the end reel 402. Alternatively, the substrate 301 may be sent to another processing unit for further processing, such as additional deposition and / or coating in a further apparatus.

[0044] The multiple nozzles 321 of the evaporation unit 350 are directed toward the curved surface 303, and the roll-to-roll unit 400 is configured to move the substrate 301 on the curved surface 303 past the evaporation unit 350. In some embodiments, multiple evaporation sources described herein can be sequentially arranged around the rotatable coating drum 310 in the circumferential direction T, allowing the substrate to be successively coated by the multiple evaporation sources. Different coating materials can be deposited on the substrate, or the evaporation sources can deposit thicker coating layers of the same coating material on the substrate.

[0045] In some embodiments, which may be combined with other embodiments described herein, the roll-to-roll unit 400 further includes an edge exclusion shield 411 extending from the roll-to-roll unit 400 toward the curved surface 303 of the drum 310.

[0046] The edge exclusion shield 411 masks the uncoated areas of the substrate 301, for example, to mask the lateral edge areas of the substrate where the coating material will not adhere. For example, the edge exclusion shield 411 can be configured to mask two opposing lateral edges of the substrate 301.

[0047] The edge exclusion shield 411 can extend in the circumferential direction T along the curved surface 303 of the drum 310 and then along the curvature of the curved surface 303. Thus, the width D of the gap between the curved surface 303 and the edge exclusion shield 411 can be kept small (e.g., 2 mm or less) and substantially constant along the circumferential direction T, thereby improving the accuracy of the edge exclusion and allowing for the deposition of sharp, well-defined coating layer edges on the substrate 301.

[0048] As shown schematically in FIG. 4A , the roll-to-roll unit 400 includes multiple tension rollers. In some embodiments, the roll-to-roll unit 400 includes a first tension roller 420 and a second tension roller 422 according to some embodiments. The first tension roller 420 receives the substrate 301 from the supply reel 401 and serves to maintain tension on the substrate 301 while it moves on the drum 310. The substrate 301 moves from the drum 310 to the second tension roller 422. The second tension roller 422 serves to maintain tension on the substrate 301 while it rolls on the drum 310. The substrate 301 moves from the second tension roller 422 to the end reel 402.

[0049] 4A , the evaporation unit 350 includes an evaporation crucible 330 for evaporating material, a vapor distributor 320 with multiple nozzles 321 for directing the evaporated material toward a substrate 301 supported on a drum 310, and a vapor conduit 340 extending in a conduit length direction from the evaporation crucible 330 to the vapor distributor 320 and providing a fluid connection between the evaporation crucible 330 and the vapor distributor 320. At least one or all of the multiple nozzles 321 can have a nozzle axis extending in a conduit length direction A or substantially parallel to the conduit length direction A. As shown in FIG. 3 , the conduit length direction A can substantially correspond to a radial direction of the drum 310.

[0050] 4A , the drum 310 includes a shell 430 and a cooling drum 410. The shell 430 is positioned radially outward from the cooling drum 410. The substrate 301 travels across an outer surface 433 of the shell 430. In some embodiments, the outer surface 433 of the shell 430 is a curved surface of the drum 310. In some embodiments, the shell 430 includes a high thermal conductivity dielectric coating, such as yttria-doped aluminum nitride, which insulates a thin metal electrode with a matched thermal expansion coefficient, such as Invar, connected to a high-voltage (e.g., greater than 600 volts) DC power supply, allowing the shell to function as an electrostatic chuck and hold the substrate 301 with a thin gap (e.g., less than 15 micrometers) between the outer surface 433 and the substrate 301.

[0051] The shell 430 and the curved outer surface of the cooling drum 410 define a cavity 431. The cavity 431 may include narrow gas channels spaced between the textured mesas to allow gas to pass between the shell 430 and the cooling drum 410. The gas then exits the cavity 431 through slits in the shell 430. In some embodiments, the gas is pressurized, forcing the substrate 301 to move over the shell 430 on an air cushion. In other embodiments, the gas is used as a heat transfer medium, allowing heat to flow smoothly through the gap and into the fluid-cooled shell 430, thereby cooling the substrate 301. The gas is at high pressure, and therefore has high thermal conductivity, enhancing the rate of thermal energy transfer. The cavity 431 is defined by the shell 430 and the curved outer surface 444 of the cooling drum 410. A support 432 is positioned within the cavity 431. The support 432 extends from the curved outer surface 344 of the cooling drum 410 to the shell 430. In some embodiments, the cooling drum 410, the support 432, and the shell 430 are a monolithic, single piece made by additive manufacturing, such as metal additive manufacturing. In other words, the drum 310 is a monolithic drum. That is, the drum 310 is a single piece formed by additive manufacturing. That is, the drum 310 is a single body formed by additive manufacturing. In some embodiments, a portion of the drum 310 is formed by additive manufacturing. For example, the cooling drum 410 is a monolithic cooling drum formed by additive manufacturing.

[0052] The cooling drum 410 is partially defined by a curved outer surface 444 and an inner surface 440. The cooling drum 410 includes an outer region 443, a channel region 442, and an inner region 441. The outer region 443, the channel region 442, and the inner region 441 are disposed between the curved outer surface 444 and the inner surface 440. The cooling drum 410 is a single body. In other words, it is a monolithic part. For example, the cooling drum 410 is a 3D printed single body. The cooling drum 410 is a metal drum with cooling channels (FIG. 4B) disposed within the channel region 442 of the cooling drum 410. The outer region 443 is disposed between the curved outer surface 444 and the channel region 442 of the cooling drum 410. In one or more embodiments, which can be combined with other embodiments, the exterior region 443 has a thickness between the curved outer surface 444 and the channel region 442 of about 0.1 millimeters and about 5 millimeters, e.g., about 1.5 millimeters for selective laser melting (SLM)-based additive manufacturing, which is thick enough to reduce the risk of pores forming between melt pools and causing leakage of the heat transfer fluid. The thinner the thickness of the exterior region 443, the higher the thermal energy transfer rate that can be achieved.

[0053] The channel region 442 is disposed between the outer region 443 and the inner region 441. The channel region 442 is disposed radially inward of the outer region 443 and radially outward of the inner region 441. In one or more embodiments that can be combined with other embodiments, the channel region 442 has a thickness between the outer region 443 and the inner region 441 of about 0.1 millimeters and about 5 millimeters, e.g., about 4 millimeters for selective laser melting (SLM)-based additive manufacturing. The thickness is selected to facilitate powder removal. In one or more embodiments that can be combined with other embodiments, the thickness is about 1.3 millimeters for high-resolution lithography printing, which improves localized fluid velocity without excessive pressure loss. The cross-sectional area of ​​the fluid channel 460 is affected by the thickness of the channel region. Gradient optimization of the hydraulic diameter or cross-sectional area of ​​the fluid channel 460 can improve convective heat transfer coefficients, thereby ensuring thermal uniformity on the exterior of the cooling drum 410 and improving deposition uniformity on the substrate 301.

[0054] The channel region 442 includes at least one or more inlets 450. While Figure 4A shows at least one or more inlets 450, including a first inlet 451, a second inlet 452, a third inlet 453, and a fourth inlet 454, other embodiments are contemplated. For example, embodiments with a single first inlet 451, two inlets 450, three inlets 450, five inlets 450, six or more inlets 450, and more inlets 450 are contemplated. The inlets 450 are connected to a fluid channel 460 (Figure 4B).

[0055] The inlets 450 are radially arranged on or around the cooling drum 410. In some embodiments, the inlets 450 are offset from one another at approximately equal angles. For example, in an embodiment having four inlets, the inlets 450 are offset from one another at approximately 90° angles. In other words, the inlets 450 may be radially arranged on the first surface 311 and / or the second surface 309.

[0056] 4B shows the internal geometry of channel region 442 according to some embodiments. While conventional manufacturing methods are unable to create an internal spiral structure in a part, various forms of additive manufacturing can provide an internal spiral cavity in a cooling drum as described herein.

[0057] The inlet 450 connects and is in fluid communication with the fluid channels 460. In some embodiments, the fluid channels 460 include a first fluid channel 461, a second fluid channel 462, a third fluid channel 463, and a fourth fluid channel 464. While only four fluid channels 460 are shown, other numbers are contemplated, such as one fluid channel 460, two fluid channels 460, three fluid channels 460, six fluid channels 460, or more than six fluid channels 460.

[0058] The first fluid channel 461 is connected to and fluidly coupled with the first inlet 451. The first inlet 451 is proximate to the first surface 311. The first fluid channel 461 is partially defined by the outer region 443 and the inner region 441 (FIG. 4A). The first fluid channel 461 forms a spiral channel around the central axis A1 of the cooling drum 410 (FIG. 4A). The first fluid channel 461 connects and communicates with a first outlet 471 of at least one or more outlets 470. The first outlet 471 is disposed on the second surface 309 of the cooling drum 410 (FIG. 4A).

[0059] The second fluid channel 462 is connected to and fluidly coupled with the second inlet 452. The second inlet 452 is proximate to the first surface 311. The second fluid channel 462 is partially defined by the outer region 443 and the inner region 441 (FIG. 4A). The second fluid channel 462 forms a spiral channel around the central axis A1 of the cooling drum 410 (FIG. 4A). The second fluid channel 462 connects and communicates with the second outlet 472 of at least one or more outlets 470. The second outlet 472 is disposed on the second surface 309 of the cooling drum 410 (FIG. 4A).

[0060] The third fluid channel 463 is connected to and fluidly coupled with the third inlet 453. The third inlet 453 is proximate to the first surface 311. The third fluid channel 463 is partially defined by the outer region 443 and the inner region 441 (FIG. 4A). The third fluid channel 463 forms a spiral channel around the central axis A1 of the cooling drum 410 (FIG. 4A). The third fluid channel 463 connects and communicates with the third outlet 473 of at least one or more outlets 470. The third outlet 473 is disposed on the second surface 309 of the cooling drum 410 (FIG. 4A).

[0061] The fourth fluid channel 464 is connected to and fluidly coupled with the fourth inlet 454. The fourth inlet 454 is proximate to the first surface 311. The fourth fluid channel 464 is partially defined by the outer region 443 and the inner region 441 (FIG. 4A). The fourth fluid channel 464 forms a spiral channel around the central axis A1 of the cooling drum 410 (FIG. 4A). The fourth fluid channel 464 connects and communicates with the fourth outlet 474 of at least one or more outlets 470. The fourth outlet 474 is disposed on the second surface 309 of the cooling drum 410 (FIG. 4A).

[0062] In some embodiments, two of the inlets 450 are located on the first face 311 and two of the inlets 450 are located on the second face 309. In this embodiment, two of the outlets are located on the first face 311 and two of the outlets 470 are located on the second face 309. By having inlets and outlets on both faces 309, 311, the cooling drum can have opposing flows of cooling fluid to achieve uniform cooling across the drum.

[0063] In some embodiments, the fluid outlet 470 of the fluid channel 460 is located proximate to the second surface 309. In some embodiments, the fluid inlet 450 of the fluid channel 460 is located proximate to the first surface 311.

[0064] The fluid outlets 470 are radially arranged on the cooling drum 410. In some embodiments, the fluid outlets 470 are offset from one another at approximately equal angles. For example, in an embodiment having four outlets, the fluid outlets 470 are offset from one another at approximately 90° angles. In other words, the fluid outlets 470 may be radially arranged on the first surface 311 and / or the second surface 309.

[0065] In some embodiments, the fluid channels 460 have a uniform number of rotations per unit length. For example, the fluid channels 460 rotate one rotation about the central axis A1 for every 100 millimeters along the central axis A1. In other words, for every 800 millimeters of the central axis A1, each of the fluid channels 461, 462, 463, 464 will rotate from about 1 to about 20 rotations about the central axis A1. In other embodiments, the fluid channels 460 vary in the number of rotations per unit length. For example, the number of rotations per unit length about the central axis A1 will increase or decrease along the central axis A1.

[0066] The fluid channels 460 are offset from one another. For example, the first fluid channel 461 is offset from the second fluid channel 462. The fluid channels 460 are partially radially offset so that they do not intersect with one another. In other words, the inlets 450 are radially distributed around the central axis A1, and the fluid channels 460 are radially offset from one another with an even distribution.

[0067] FIG. 4C is a schematic partial cross-sectional view of drum 310 taken along line 4C-4C of FIG. 4B, according to some embodiments. As shown, each fluid channel 460 forms a parallel spiral channel within cooling drum 410. As shown, substrate 301 receives gas from multiple gas slits 480. Slits 480 are openings in outer surface 433 of shell 430. Gas is supplied to cavity 431 by gas inlets 481. Gas inlets 481 are disposed on first surface 311, according to some embodiments. In some embodiments, multiple gas inlets 481 are present. In some embodiments, a gas inlet is present on second surface 309. In some embodiments, a gas inlet is present on both first surface 311 and second surface 309.

[0068] During operation, as the substrate 301 receives thermal energy, the thermal energy is transferred from the substrate to the gas. The thermal energy is then transferred from the gas to the outer surface 444 of the cooling drum 410. To further remove thermal energy from the substrate 301, a coolant is flowed through the fluid channels 460 to maintain the temperature of the substrate 301 below 180.5°C, which is near the melting point of lithium. More specifically, the temperature level of the substrate 301 is maintained below 70°C, which is the glass transition or softening temperature of the polymer binder in some anodes. For example, this is below 10°C, which is the typical operating setpoint for commercially available water-glycol heat exchangers. For example, when using a silicone oil heat exchanger, this is below -30°C for high-throughput lithium web coating.

[0069] The spiral shape of the fluid channel 460 increases the amount of heat energy that can be removed by the coolant through secondary circulation. The spiral design achieved by additive manufacturing allows for a small distance 483 between the substrate 301 and the fluid channel 460. For example, the distance 483 between the fluid channel 460 disposed in the channel region 442 and the substrate 301 is between about 1 millimeter and about 10 millimeters. The distance 483 between the fluid channel 460 disposed in the channel region 442 and the substrate 301 includes the radial thickness of the outer region 443, the radial thickness of the cavity 431, the radial thickness of the shell 430, and any gap formed by the gas cushion 484 between the substrate 301 and the shell. The gas cushion 484 has a thickness defined by the radial thickness between the shell 430 and the substrate 301. In some embodiments, the gas cushion has a thickness between about 1 micrometer and 110 micrometers, e.g., less than 80 micrometers.

[0070] In some embodiments, the substrate 301 moves along the shell 430 and is not separated by a gas cushion. Without a gas cushion, the shell 430 further facilitates the removal of thermal energy through conductive heat transfer. Therefore, greater cooling can be achieved by additively manufacturing the entire drum 310 from a material with a high thermal energy transfer coefficient. For example, the substrate 301 can be cooled more efficiently by forming the drum from aluminum, copper, copper alloys, aluminum alloys, aluminum materials, and / or copper-containing materials. Other materials with thermal energy transfer coefficients that enhance the rate of heat transfer from the substrate 301 to the cooling drum 410 are also contemplated.

[0071] 5A and 5B show schematic views of the interior of a fluid channel 460 according to some embodiments. The fluid channel 460 includes a surface feature 501. Figure 5A shows a schematic cross-sectional view of the fluid channel 460 perpendicular to the fluid flow according to some embodiments.

[0072] The surface feature 501 can be on an outer diameter surface 503 between the exterior region 443 and the channel region 442. The surface feature 501 can be on an inner diameter surface 505 between the interior region 441 and the channel region 442. The surface feature 501 can be on one or more sidewalls 507 within the channel region 442.

[0073] FIG. 5B shows a schematic cross-sectional view of a fluid channel 460 (inner diameter surface 505, outer diameter surface 503, and sidewall 507 of each inner surface 510 of the fluid channel 460) according to some embodiments.

[0074] 5B, fluid channel 460 has a rectangular shape according to some embodiments. In some embodiments, fluid channel 460 has a trapezoidal shape. In some embodiments, fluid channel 460 has a circular shape. In some embodiments, fluid channel 460 forms a porous gyroid.

[0075] The surface features 501 can be turbulators and / or turbulent surface features. For example, the surface features 501 can be gyroid-shaped turbulators and / or turbulent gyroid surface features configured to prevent laminar flow. Additive manufacturing (AM) can be used to add gyroid-shaped, high-surface-area, periodic turbulent features to the inner surface 510 while minimizing the distance thermal energy must travel. Metal AM can be applied to the drum 310 to create porous, three-dimensional gyroids that function as turbulators for the heat exchanger integrated into the cooling drum 410, improving the cooling capacity of the drum 310. The surface features 501 accelerate the coolant flow velocity, thereby preventing a uniform gradient in the L-direction fluid channels 460 shown in FIG. 3 . This acceleration occurs by reducing the hydraulic diameter or cross-sectional area of ​​the fluid channels 460. The gradient modulation of the surface features 501 increases the wetted area participating in heat transfer, resulting in increased heat transfer to the fluid due to heat extraction from the shell 430 along the flow path length of the fluid channel 460. The surface features 501 enhance the cooling capacity of the fluid channel 460 by compensating for the temperature increase of the coolant flow and providing a uniform temperature in the fluid channel 460, thereby forcing a uniform and larger temperature difference between the outer diameter surface 503 and the exterior region 443. The shape optimization of the turbulators reduces the uniform coolant flow in the fluid channel, thus compensating for the increased oil temperature gradient. Reducing the thermal gradient in the cooling in the fluid channel results in a more uniform drum surface temperature and minimizes non-uniformity in the substrate coating.

[0076] The surface features 501 facilitate non-laminar coolant flow. For example, the surface features 501 facilitate a coolant flow Reynolds number between about 2300 and about 4000. For example, the surface features 501 facilitate a coolant flow Reynolds number between about 2300 and about 4000 when the coolant is flowed at a velocity between about 0.5 meters / second and about 5 meters / second, e.g., 1 meter / second.

[0077] 6 illustrates a method 600 for cooling a substrate while using a roll-to-roll deposition system. In operation 601, a coolant is supplied to a fluid channel 460 in the cooling drum 410 of the drum 310. As the coolant flows through the first fluid channel 461, the coolant is turbulent to achieve a uniform temperature distribution perpendicular to the coolant flow.

[0078] In operation 603, a gas is supplied to the cavity 431 of the drum 310. The gas can be an inert gas. For example, the gas is argon. For example, the gas is carbon dioxide. Other gases are also contemplated.

[0079] In operation 605, the evaporation unit deposits a material on the substrate 301. The material can be a lithium anode material. In some embodiments, the material can be a lithium material deposited on a polymer substrate with a graphite layer disposed thereon for prelithiation.

[0080] The foregoing embodiments of the present disclosure have many advantages, including: The apparatus provided herein enables 50,000 watts / square meter heat load vacuum web coating with a temperature differential from the drum surface to the coolant channels of less than 35°C and a temperature non-uniformity across the drum surface of less than 4°C. The present disclosure provides lithium deposition rates of about 5 micrometers / minute to about 60 micrometers / minute, or greater than 60 micrometers / minute, in transfer laminates and LIB anode webs. For example, the present disclosure achieves lithium deposition rates of about 10 micrometers / minute to about 20 micrometers / minute in transfer laminates and LIB anode webs. However, the present disclosure does not require that all advantageous features and benefits of the present invention be incorporated into every embodiment of the present disclosure.

[0081] The present disclosure increases the heat transfer area of ​​the cooling channels and reduces boundary layer thickness, enabling high deposition rates and low deposition thickness non-uniformity, improving coating economy and yield. The drum utilizes metal additive manufacturing to create a three-dimensional gyroid with optimized porosity that serves as the turbulators of a heat exchanger integrated into the cooling drum. A gas, such as an inert gas, is distributed between the cooling drum and the shell. The cooling drum and / or shell can be additively manufactured. The cooling drum assembly further includes a fluid flowing through the additively manufactured body to improve cooling rates. Optimizing the turbulator geometry reduces uniform coolant flow within the fluid channels, thus compensating for increased oil temperature gradients. Reducing the thermal gradient within the cooling within the fluid channels results in a more uniform drum surface temperature and minimizes substrate coating non-uniformity. Copper or aluminum alloys can be utilized in additive manufacturing processes to form the drum. A drum for vapor deposition is shown and described herein. A vapor deposition apparatus including a drum is shown and described herein. A method for coating a substrate is shown and described herein.

[0082] While the above is directed to exemplary embodiments, other and further embodiments may be devised without departing from the basic scope thereof, the scope of which is determined by the claims that follow.

Claims

1. 1. A drum for vapor deposition, the drum comprising: a shell having a gas slit; and Cooling drum wherein the cooling drum comprises: external area, internal area, a first fluid channel defined in part by the exterior region and the interior region, the first fluid channel forming a helical channel about a central axis of the cooling drum; and a first inlet in fluid communication with a first outlet via the first fluid channel; 1. A drum for vapor deposition comprising:

2. 10. The drum of claim 1, wherein the cooling drum is a monolithic drum made of copper or aluminum alloy.

3. The drum of claim 1 , wherein the first fluid channel includes turbulent surface features.

4. 2. The drum of claim 1, wherein the cooling drum further comprises a second fluid channel radially offset from the first cooling channel and defined in part by the outer region and the inner region, the second fluid channel forming a helical channel about the central axis of the cooling drum.

5. The drum of claim 4 , wherein the second fluid channel connects a second fluid inlet to a second fluid outlet.

6. The drum of claim 4 , wherein the first inlet and second inlet are located in a first face of the cooling drum.

7. 5. The drum of claim 4, wherein the first inlet and second outlet are located in a first face of the cooling drum and the second inlet and first outlet are located in a second face of the cooling drum.

8. 10. The drum of claim 1, wherein the distance between the shell and the curved surface of the outer region of the cooling drum is between about 1 millimeter and about 5 millimeters.

9. 2. The drum of claim 1, wherein the first inlet is positioned proximate a first surface of the cooling drum and the first outlet is positioned proximate a second surface of the cooling drum, the second surfaces being separated by a curved surface of the cooling drum.

10. 10. The drum of claim 1, wherein the outer region has a thickness of less than 10 millimeters.

11. 1. A roll-to-roll deposition system, comprising: Evaporation unit, a plurality of tension rollers; and a drum disposed between the plurality of tension rollers and the evaporator unit; wherein the drum comprises: a shell having a gas slit; A cooling drum comprising: external area, internal area, a first fluid channel defined in part by the exterior region and the interior region, the first fluid channel forming a helical channel about a central axis of the cooling drum; and a first inlet in fluid communication with a first outlet via the first fluid channel; a cooling drum having 1. A roll-to-roll deposition system comprising:

12. 12. The roll-to-roll deposition system of claim 11, wherein the cooling drum is monolithic and made of a copper or aluminum alloy.

13. 12. The roll-to-roll deposition system of claim 11 , wherein the cooling drum further comprises a second fluid channel radially offset from the first cooling channel and defined in part by the outer region and the inner region, the second fluid channel forming a helical channel about the central axis of the cooling drum.

14. The roll-to-roll deposition system of claim 13 , wherein the first inlet and the second inlet are located on a first surface of the cooling drum.

15. 14. The roll-to-roll deposition system of claim 13, wherein the first inlet is located on a first side of the cooling drum and the second inlet is located on a second side of the cooling drum.

16. The roll-to-roll deposition system of claim 11 , wherein the first fluid channel comprises turbulent surface features.

17. 1. A method of applying an anode material to a substrate, comprising: supplying a coolant to a drum, said drum comprising: Shell, and a cooling drum having a first fluid channel disposed radially inward of the shell and defined in part by an outer region of the cooling drum and an inner region of the cooling drum, the first fluid channel forming a helical channel about a central axis of the cooling drum, the first fluid channel having turbulent surface features. supplying a coolant to the drum; flowing a coolant through the first fluid channel; flowing a gas through a cavity between the shell and the cooling drum; rolling a substrate on the shell; and evaporating an anode material onto said substrate. A method comprising:

18. 18. The method of claim 17, wherein the coolant is flowed at a velocity of less than 1 meter per second.

19. 20. The method of claim 17, wherein gas exiting the shell through a plurality of gas slits forms a gas cushion between the substrate and the shell, the gas cushion being less than 15 micrometers.

20. 18. The method of claim 17, wherein the coolant flow has a Reynolds number between about 2300 and about 4000.

Images