Prelithiated and lithium metal free anode coatings

Abstract

Methods and systems are provided for forming lithium anode devices. In one embodiment, the methods and systems form pre-lithiated Group IV alloy type nanoparticles (NPs), e.g., Li-Z (Z is Ge, Si, or Sn). In another embodiment, the methods and systems synthesize Group IV nanoparticles and alloy the Group IV nanoparticles with lithium. The Group IV nanoparticles can be prepared on demand and premixed with or coated onto the anode material. In yet another embodiment, the methods and systems form lithium metal-free silver-carbon ("Ag-C") nanocomposites (NCs). In yet another embodiment, a method is provided for making an anode coating that utilizes silver (PVD) and carbon (PECVD) co-deposition to tune the lithium nucleation energy to minimize dendrite formation.

Description

[Technical field]

[0001] Field FIELD OF THE DISCLOSURE Embodiments described herein generally relate to deposition systems and methods for processing flexible substrates. In particular, the embodiments relate to systems and methods for forming anode structures on flexible substrates. [Background technology]

[0002] Rechargeable electrochemical storage systems are gaining importance in many areas of daily life. High-capacity energy storage devices, such as lithium-ion (Li-ion) batteries and capacitors, are increasingly being used in many applications, including portable electronics, medical, transportation, grid-connected large-scale energy storage, renewable energy storage, and uninterruptible power supplies (UPS). In each of these applications, the time and capacity of the energy storage device to charge and discharge are important parameters. In addition, the size, weight, and / or cost of such energy storage devices are also important parameters. Furthermore, low internal resistance is essential for high performance. The lower the resistance, the less constraint the energy storage device faces in delivering electrical energy. For example, in the case of a battery, the internal resistance affects performance by reducing the total amount of useful energy that the battery stores and reducing the battery's ability to deliver high currents.

[0003] Li-ion batteries are believed to offer the best chance of achieving the required capacity and cycling, however, current configurations of Li-ion batteries often fall short in terms of energy capacity and number of charge / discharge cycles for these growing applications.

[0004] Thus, there is a need in the art for faster charging, higher capacity energy storage devices that have improved cycling and can be manufactured more cost effectively. Additionally, there is a need for components for energy storage devices that reduce the internal resistance of the storage devices. Summary of the Invention

[0005] FIELD OF THE DISCLOSURE Embodiments described herein generally relate to vacuum deposition systems and methods for processing flexible substrates. In particular, the embodiments relate to roll-to-roll vacuum deposition systems and methods for forming anode structures on flexible substrates.

[0006] In one or more embodiments, a method of making lithiated Group IV nanoparticles is provided. The method includes introducing a layer of Group IV nanoparticles to a heated mixing vessel. The method further includes introducing a layer comprising lithium to the heated mixing vessel. The method further includes sequentially repeating the introduction of the layer of Group IV nanoparticles and the layer comprising lithium to the heated mixing vessel. The method further includes alloying the Group IV nanoparticles with lithium to form lithiated Group IV nanoparticles.

[0007] In another embodiment, the group IV nanoparticles are formed from a non-thermal plasma synthesis process. The lithiated group IV nanoparticles are pre-lithiated reagents that are stable in air. Introducing the layer of group IV nanoparticles to the heated mixing vessel includes providing molten lithium in the heated mixing vessel. Introducing the layer of group IV nanoparticles to the heated mixing vessel includes providing lithium powder in the heated mixing vessel. The lithiated group IV nanoparticles are applied to the graphite anode to form the pre-lithiated graphite anode. Applying the lithiated group IV nanoparticles to the graphite anode to form the pre-lithiated graphite anode includes an industrial shifter feeder process. Applying the lithiated group IV nanoparticles to the graphite anode to form the pre-lithiated graphite anode includes an electrospray process. The group IV nanoparticles are selected from silicon nanoparticles, germanium nanoparticles, tin nanoparticles, carbon nanoparticles, or any combination thereof. The heated mixing vessel is a rotating planetary mixer. The lithiated group IV nanoparticles are mixed to form a slurry. Mixing the lithiated Group IV nanoparticles to form a slurry includes mixing the lithiated Group IV nanoparticles with a conductive additive, a binder, a solvent, or any combination thereof, and the slurry is cast onto the anode structure to form a pre-lithiated alloy-type anode.

[0008] In some embodiments, a system for forming an anode structure is provided. The system includes a lithium source module operable to supply lithium. The system further includes a Group IV nanoparticle source module operable to supply Group IV nanoparticles. The system further includes a mixing vessel assembly capable of heating the lithium and the Group IV nanoparticles to produce pre-lithiated Group IV alloy-type nanoparticles.

[0009] In one or more embodiments, the system further includes a deposition source module capable of depositing the pre-lithiated Group IV alloy type nanoparticles on the substrate. The deposition source module includes a shifter body, a hopper assembly, and a delivery conduit fluidly coupling the hopper assembly and the shifter body. The deposition source module includes a deposition module defining a processing environment, a coating drum positioned within the processing environment and operable to transport the flexible substrate, and an electrospray gun positioned within the processing environment and operable to deposit the pre-lithiated Group IV alloy type nanoparticles on the flexible substrate. The electrospray gun is a triboelectric powder spray gun or a corona spray gun. The system includes a hopper assembly operable to store and deliver the lithiated Group IV alloy type nanoparticles to the electrospray gun.

[0010] In another embodiment, a method of forming an anode structure is provided that includes forming a silver-carbon (Ag-C) nanocomposite on a current collector web, where forming the silver-carbon (Ag-C) nanocomposite includes sputtering silver onto the current collector web simultaneously with plasma enhanced chemical vapor deposition of amorphous carbon to form a silver-carbon nanocomposite on the current collector.

[0011] In one or more embodiments, a layer of lithium is deposited on the silver-carbon nanocomposite or on top of the silver-carbon nanocomposite. The layer of lithium can be deposited on the silver-carbon nanocomposite by thermally evaporating lithium. Sputtering silver onto the current collector is performed using a DC sputtering gun.

[0012] In another embodiment, a flexible substrate coating system is provided. The system includes an unwinding module housing a feed reel capable of providing a continuous sheet of flexible material. The method further includes a take-up module housing a take-up reel capable of storing the continuous sheet of flexible material. The method further includes a processing module disposed downstream of the unwinding module. The processing module includes a plurality of subchambers arranged in sequence, each subchamber configured to perform one or more processing operations on the continuous sheet of flexible material. The system further includes a coating drum capable of guiding the continuous sheet of flexible material through the plurality of subchambers along a direction of travel, the subchambers being radially disposed around the coating drum. A first subchamber of the plurality of subchambers includes a first deposition source operable to deposit silver and a second deposition source operable to deposit carbon.

[0013] In one or more embodiments, the first deposition source is a physical vapor deposition (PVD) source and the second deposition source is a plasma enhanced chemical vapor deposition (PECVD) source. The physical vapor deposition source includes a DC sputtering gun and the PECVD source includes an electrode showerhead. The first subchamber is defined by a subchamber body over which an edge shield is positioned. The edge shield has one or more apertures that define a pattern of evaporated material to be deposited on the continuous sheet of flexible material. The coating system further includes a second subchamber including a thermal evaporation source. The thermal evaporation source is configured to deposit lithium metal.

[0014] In another embodiment, a method of forming a lithium-free silver-carbon (Ag-C) based slurry is provided. The method includes forming silver nanoparticles via a spray pyrolysis process. The method further includes combining the silver nanoparticles with a conductive additive, a binder, and a solvent in a heated mixing vessel to form the lithium-free silver-carbon (Ag-C) based slurry.

[0015] Embodiments may include one or more of the following: The conductive additive is selected from the group of graphite, graphene hard carbon, carbon black, carbon coated silicon, or any combination thereof. The binder is selected from the group of styrene-butadiene rubber, acrylated styrene-butadiene rubber, acrylonitrile copolymer, acrylonitrile-butadiene rubber, nitrile butadiene rubber, acrylonitrile-styrene-butadiene copolymer, acrylic rubber, butyl rubber, fluororubber, polytetrafluoroethylene, polyethylene, polypropylene, ethylene / propylene copolymer, polybutadiene, polyethylene oxide, chlorosulfonated polyethylene, polyvinylpyrrolidone, polyvinylpyridine, polyvinyl alcohol, polyvinyl acetate, polyepichlorohydrin, polyphosphazene, polyacrylonitrile, polystyrene, latex, acrylic resin, The polymer may be selected from phenolic resins, epoxy resins, carboxymethyl cellulose, hydroxypropyl cellulose, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethyl cellulose, cyanoethyl sucrose, polyesters, polyamides, polyethers, polyimides, polycarboxylates, polycarboxylic acids, polyacrylic acids, polyacrylates, polymethacrylic acids, polymethacrylates, polyacrylamides, polyurethanes, fluorinated polymers, chlorinated polymers, salts of alginic acid, polyvinylidene fluoride, poly(vinylidene fluoride)-hexafluoropropene, or any combination thereof. The solvent is selected from N-methyl-2-pyrrolidone, dimethylformamide, dimethylsulfoxide, acetonitrile, butylene carbonate, propylene carbonate, ethyl bromide, tetrahydrofuran, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, methyl propyl carbonate, ethylene carbonate, water, pure water, deionized water, distilled water, ethanol, isopropanol, methanol, acetone, n-propanol, t-butanol, or any combination thereof.

[0016] In some embodiments, a non-transitory computer-readable medium stores instructions that, when executed by a processor, cause the processor to perform operations of the apparatus and / or methods described above. [Brief description of the drawings]

[0017] So that the above-mentioned features of the present disclosure can be understood in detail, a more particular description of the above briefly summarized embodiments will be obtained by reference to the embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the present disclosure is also open to other equally effective embodiments, and therefore, that the accompanying drawings only illustrate typical embodiments of the present disclosure, and should not be considered as limiting the scope of the present disclosure.

[0018] [Figure 1] 1 is a schematic cross-sectional view of one example of a flexible layer stack formed in accordance with one or more embodiments described herein. [Diagram 2] FIG. 1 is a process flow diagram summarizing one embodiment of a method of forming an anode structure according to one or more embodiments. [Diagram 3] FIG. 1 is a schematic diagram of a system for forming an anode structure according to one or more embodiments. [Figure 4] FIG. 1 is a schematic diagram of an example of a lithium source system according to one or more embodiments. [Diagram 5] FIG. 2 is a schematic diagram of another example of a lithium source system according to one or more embodiments. [Figure 6] FIG. 1 is a schematic diagram of an example of a Group IV nanoparticle source system according to one or more embodiments. [Figure 7] FIG. 2 is a schematic diagram of another example of a Group IV nanoparticle source system according to one or more embodiments. [Figure 8] FIG. 1 is a schematic diagram of a mixing vessel assembly according to one or more embodiments. [Figure 9] FIG. 1 is a schematic diagram of a deposition system according to one or more embodiments. [Figure 10]FIG. 1 is a schematic diagram of another deposition system according to one or more embodiments. [Figure 11] FIG. 1 is a process flow diagram summarizing a method of forming a silver-carbon (Ag—C) nanocomposite according to one or more embodiments. [Figure 12] FIG. 1 is a schematic diagram of a system for forming a silver-carbon (Ag—C) nanocomposite according to one or more embodiments. [Figure 13] FIG. 1 is a schematic diagram of another system for forming a silver-carbon (Ag—C) nanocomposite according to one or more embodiments. [Figure 14] FIG. 1 is a schematic diagram of a system for forming a silver-carbon (Ag—C) slurry according to one or more embodiments. [Figure 15] FIG. 1 is a schematic diagram of a spray pyrolysis system according to one or more embodiments.

[0019] To facilitate understanding, wherever possible, like reference numerals have been used to designate like elements common to the figures, and it is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] The following disclosure describes systems and methods for forming anode structures on flexible substrates. Specific details are set forth in the following description and in Figures 1-15 to provide a thorough understanding of various embodiments of the present disclosure. Other details describing well-known structures and systems often associated with energy storage devices and anode structures are not set forth in the following disclosure to avoid unnecessarily obscuring the description of the various embodiments.

[0021] Many of the details, dimensions, angles, and other features shown are merely illustrative of particular embodiments. Thus, other embodiments can have other details, components, dimensions, angles, and features without departing from the spirit or scope of the present disclosure. In addition, further embodiments of the present disclosure can be practiced without some of the details described below.

[0022] Some embodiments described herein are described in the context of a roll-to-roll coating system, such as the TopMet® roll-to-roll web coating system, the SMARTWEB® roll-to-roll web coating system, and the TOPBEAM® roll-to-roll web coating system, all of which are available from Applied Materials, Inc. (Santa Clara, Calif.). Other tools capable of performing high-speed deposition processes may also be adapted to benefit from the embodiments described herein. In addition, any system that enables the deposition processes described herein may be advantageously used. The apparatus descriptions described herein are exemplary and should not be understood or construed as limiting the scope of the embodiments described herein. Although described as a roll-to-roll process, it should also be understood that the embodiments described herein may also be performed on separate substrates.

[0023] Some embodiments described herein are described below in relation to a roll-to-roll coating system. The apparatus description described herein is exemplary and should not be understood or interpreted as limiting the scope of the embodiments described herein. Also, although described as a roll-to-roll process, it should be understood that the embodiments described herein can be implemented on other types of substrates, even separate substrates.

[0024] Some embodiments described herein refer to a coating system adapted for prelithiation of flexible substrates, e.g., webs for lithium-ion battery devices. In particular, the coating system is adapted for continuous processing of flexible substrates, e.g., webs unwound from an unwinding module. The coating system can be configured in a modular design, e.g., a suitable number of processing modules can be arranged next to each other in a processing step, and the flexible substrate can be inserted into the first processing module and ejected from the last processing module in the step. Furthermore, the entire coating system can be reconfigured if changes to individual processing operations are desired.

[0025] While the particular substrates on which some embodiments described herein may be practiced are not limited, it should be noted that it is particularly advantageous to practice the embodiments on flexible substrates, including, for example, web-based substrates, panels, and discrete sheets. The substrate may be in the form of a foil, film, or sheet.

[0026] It should also be noted here that the flexible substrate or web used in the embodiments described herein can typically be characterized as being bendable. The term "web" may be used synonymously with the term "strip" or "flexible substrate." For example, the web described in the embodiments herein may be a foil.

[0027] It is further noted that in some embodiments where the substrate is a vertically oriented substrate, the vertically oriented substrate may be angled with respect to the vertical plane. For example, in some embodiments, the substrate may be angled between about 1 degree and about 20 degrees from the vertical plane. In some embodiments where the substrate is a horizontally oriented substrate, the horizontally oriented substrate may be angled with respect to the horizontal plane. For example, in some embodiments, the substrate may be angled between about 1 degree and about 20 degrees from the horizontal plane. As used herein, the term "vertical" is defined as the major surface or deposition surface of the flexible conductive substrate being perpendicular to the horizontal. As used herein, the term "horizontal" is defined as the major surface or deposition surface of the flexible conductive substrate being parallel to the horizontal.

[0028] Energy storage devices, such as batteries, typically include a positive electrode, an anode electrode separated by a porous separator, and an electrolyte used as an ion-conducting matrix. Graphite anodes are the current state of the art, but the industry is moving away from graphite-based anodes to silicon-mixed graphite anodes to increase the energy density of the cells. However, silicon-mixed graphite anodes often suffer from irreversible capacity loss during the first cycle. Therefore, a method is needed to replenish this first cycle capacity loss. Prelithiation of anode materials is one available method to replenish the first cycle capacity loss.

[0029] Chemical prelithiation, electrochemical prelithiation, prelithiation by direct contact with lithium metal, and stabilized lithium metal powder ("SLMP") TM Various anode prelithiation methods exist, including the "Li-ion battery prelithiation method." These existing prelithiation methods share common Li-ion battery mass production drawbacks, such as long reaction times and inherent safety risks, which make them unsuitable for lithium-ion battery mass production.

[0030] For example, SLMPTM In the case of SLMP, up to 30% of the Li2CO3 powder shells remain unbroken. These unbroken shells are then incorporated into the cell mass as inert material that reduces the energy density of the Li-ion battery. TM Loose powders that migrate within the electrolyte during dispersion also present unique safety and reliability risks. Electrochemical prelithiation creates reactive materials in the surrounding air that can increase the impedance of the cell due to nitrogen and oxygen contamination. Direct access to lithium metal is a heterogeneous, low-yield process hindered by discontinuous thin lithium metal foils up to 60 centimeters wide and 20 meters long.

[0031] Deposition of lithium metal is another method to replenish such first cycle capacity loss of silicon-mixed graphite anodes. Although numerous methods exist for lithium metal deposition, e.g., thermal evaporation, lamination, or printing, handling of the lithium metal deposited on a spool prior to device lamination must be addressed, especially in a mass production environment. To address these handling issues, the web coating of the anode often includes a thin protective layer coating. In the absence of a protective layer coating, the surface of the lithium metal is susceptible to harmful corrosion and oxidation. Lithium carbonate (Li2CO3) films are currently used as protective layer coatings for lithium. However, lithium carbonate protective layers present several challenges. For example, the carbonate coating consumes lithium, thereby increasing the amount of "dead lithium" and correspondingly reducing the coulombic efficiency. Current deposition processes for lithium carbonate can lead to the formation of lithium oxide instead of lithium carbonate, which is an undesirable SEI component. In addition, carbonate coatings are difficult to activate when the carbonate adsorption rate is low, which can lead to large variations in the coating uniformity of the carbonate coating in both the vertical and horizontal directions. Furthermore, CO2 adsorption lacks line-of-sight scalability and is therefore a process that is not suitable for most high volume protective layer coatings, including sacrificial and protective applications.

[0032] In one aspect, methods and systems are provided for forming lithium anode devices. In one embodiment, methods and systems are provided for forming prelithiated Group IV alloy type nanoparticles (NPs), e.g., Li-Z (Z is Ge, Si, or Sn). In another embodiment, methods and systems are provided for synthesizing Group IV nanoparticles and alloying the Group IV nanoparticles with lithium. The Group IV nanoparticles can be prepared on demand and premixed with the anode material or coated onto the anode material. In yet another embodiment, methods and systems are provided for forming lithium metal-free silver-carbon ("Ag-C") nanocomposites (NCs). In yet another embodiment, methods are provided for using silver (PVD) and carbon (PECVD) co-deposition to create anode coatings that can tune the lithium nucleation energy to minimize dendrite formation.

[0033] In some embodiments, a deposition module is provided for in situ delivery of lithium and gas-synthesized Group IV nanoparticles for use as prelithiated reservoirs. Providing nanoparticles integrated in a slurry can be used to facilitate SLMP. TM The module reduces the need for hazardous calendaring that is typically required to crack the shell of a current collector. Additionally, the module for producing nanocomposite coatings on current collectors offers novel alloying process control that minimizes dendrite formation. Conventional web coating equipment typically lacks the ability to apply air-stable pre-lithiated particles and / or the ability to alloy metallic lithium films as deposited.

[0034] In some embodiments, the Li-Z nanoparticles described and disclosed herein (where Z is Ge, Si, or Sn, or any combination thereof) do not include a stabilizing shell, thereby allowing for SLMP. TMThe need for dangerous pressure-based crack activation associated with lithium carbonate shell cracking is eliminated. In one or more embodiments, the Li-Z nanoparticles can have an atomic ratio of Li:Z of about 1:1, about 1.5:1, about 2:1, about 2.5:1, or about 3:1 to about 3.5:1, about 3.8:1, about 4:1, about 4.2:1, about 4.5:1, about 4.8:1, about 5:1, about 5.5:1, about 6:1, or more. In some embodiments, the Li-Z nanoparticles described herein can be SLMP-based. TM The Ag-C nanocomposite layer is smaller and therefore can be applied uniformly or variably on or across the anode material. In some embodiments, the roll-to-roll web approach of Ag-C nanocomposite layer formation described herein facilitates higher process tunability (carbon matrix porosity, pore anisotropy, and silver immobilization) and higher yields when compared to slurry-based casting methods.

[0035] In some embodiments, lithium-germanium alloy nanoparticles, e.g., Li 22 Ge5 nanoparticles are obtained from a metallurgical alloying process in which molten lithium and germanium nanoparticles are introduced. Germanium nanoparticles can be obtained from non-thermal plasma synthesis of germanium-halide sources, such as GeCl4 sources. To reduce the alloying time, both lithium and germanium nanoparticles can be added in sequential layers. After the process is completed, the particles can be mixed in slurry form with, for example, carbon additives, binders, and solvents, and cast using conventional slurry-based methods, such as slot-die coating. Alternatively, Group IV nanoparticles serve as a stable lithium-bearing agent and are applied onto a graphite-coated current collector using conventional powder coating methods and calendaring, followed by heating for adhesion.

[0036] In some embodiments, the Ag-C nanocomposite layer is obtained by simultaneously sputtering silver onto the substrate and onto the coated carbon, for example via plasma enhanced chemical vapor deposition (PECVD). Optionally, lithium can then be evaporated onto the web to prelithiate the Ag-C nanocomposite layer.

[0037] FIG. 1 is a schematic cross-sectional view of an example of a flexible layer stack 100 formed according to one or more embodiments described herein. The flexible layer stack 100 can incorporate Group IV lithium alloy nanoparticles and / or Ag-C nanocomposites as described and disclosed herein. The flexible layer stack 100 can be formed using the methods and systems described herein. The flexible layer stack 100 can be a pre-lithiated anode structure. The flexible layer stack 100 shown in FIG. 1 includes a continuous flexible substrate 110 having multiple film stacks 112a, 112b (collectively 112) formed on both sides of the continuous flexible substrate 110. Each film stack 112a, 112b includes a first layer 120a, 120b (collectively 120), a second layer 130a, 130b (collectively 130), and an optional third layer 140a, 140b (collectively 140).

[0038] 1 has three layers on each side of a continuous flexible substrate 110, those skilled in the art will appreciate that flexible layer stack 100 can have more or fewer layers, which can be provided above, below, and / or between the continuous flexible substrate 110, first layer 120, second layer 130, and / or third layer 140 as shown in FIG 1. Although shown as a double-sided structure, those skilled in the art will appreciate that flexible layer stack 100 can also be a single-sided structure having a continuous flexible substrate 110, first layer 120, second layer 130, and optionally third layer 140.

[0039] According to some embodiments described herein, the continuous flexible substrate 110 can include a first material and / or the first layer 120 can include a second material. Furthermore, the second layer 130 can include a third material. Additionally, the third layer 140 can include a fourth material. For example, the first material can be a conductive material, typically a metal such as copper (Cu) or nickel (Ni). Furthermore, the continuous flexible substrate 110 can include one or more sub-layers. In one embodiment, the second material can be an anode material composed of graphite, silicon, silicon-containing graphite, lithium metal, lithium metal foil or lithium alloy foil (e.g., lithium aluminum alloy), or a mixture of lithium metal and / or lithium alloy with materials such as carbon (e.g., coke, graphite), nickel, copper, tin, indium, silicon, oxides thereof, or any combination thereof. The second material can further include a binder material. In another embodiment, the second material is a silver-carbon nanocomposite material as described and disclosed herein. The third material can be a prelithiated material. In one embodiment, the third material can be a low melting temperature metal, e.g., an alkali metal such as lithium. In another embodiment, the third material comprises Group IV lithium alloy nanoparticles as described and disclosed herein. The fourth material can be a protective or interleaved film operable to protect the low melting temperature metal of the third layer.

[0040] Typically, in prismatic cells, the tabs are formed of the same material as the current collectors and may be formed during the manufacture of the stack or may be added later. In some embodiments, as shown in FIG. 1, the continuous flexible substrate 110 extends beyond the film stack 112, and the portion of the continuous flexible substrate 110 that extends beyond the film stack 112 may be used as a tab. For example, either the uncoated portion of the continuous flexible substrate 110 exposed along a proximal end 113 of the continuous flexible substrate 110 and / or the uncoated strip along a distal end 117 of the continuous flexible substrate 110 may be used to form a tab.

[0041] According to some embodiments described herein, the continuous flexible substrate 110 can have a thickness of about 25 μm or less, typically 20 μm or less, specifically 15 μm or less, and / or typically 3 μm or more, specifically 5 μm or more. The continuous flexible substrate 110 can be thick enough to provide its intended function and thin enough to be flexible. Specifically, the continuous flexible substrate 110 can be thinned to the extent that the continuous flexible substrate 110 can still provide its intended function.

[0042] According to some embodiments described herein, the first layer 120 can have a thickness of 10 μm or less, typically 8 μm or less, advantageously 7 μm or less, particularly 6 μm or less, and especially 5 μm or less. According to some embodiments, the thickness of the first layer 120 can be 4 μm or less, or 3 μm or less, or 2 μm or less.

[0043] According to some embodiments described herein, the second layer 130 can have a thickness of 10 μm or less, typically 8 μm or less, advantageously 7 μm or less, particularly 6 μm or less, and especially 5 μm or less. According to some embodiments, the thickness of the second layer 130 can be 4 μm or less, or 3 μm or less, or 2 μm or less.

[0044] The flexible layer stack 100 shown in Fig. 1 can be, for example, a negative electrode of / for a secondary battery, such as a negative electrode or anode of / for a lithium battery. According to some embodiments described herein, the flexible negative electrode for a lithium battery includes a continuous flexible substrate 110, which can be a current collector comprising copper and having a thickness of 10 μm or less, typically 8 μm or less, advantageously 7 μm or less, particularly 6 μm or less, and especially 5 μm or less. The flexible negative electrode further includes a first layer 120 comprising graphite and having a thickness of 5 μm or more and / or 15 μm or less, and a second layer 130 comprising the Group IV lithium alloy nanoparticles as described and disclosed herein, having a thickness of 5 μm or more and / or 15 μm or less.

[0045] According to some embodiments described herein, a flexible negative electrode for a lithium battery includes a flexible substrate 110, which may be a current collector comprising copper and having a thickness of 10 μm or less, typically 8 μm or less, advantageously 7 μm or less, particularly 6 μm or less, and especially 5 μm or less. The flexible negative electrode further includes a first layer 120 comprising a silver-carbon (Ag-C) nanocomposite having a thickness of 5 μm or more and / or 15 μm or less, and a second layer 130 comprising a lithium metal layer having a thickness of 5 μm or more and / or 15 μm or less.

[0046] According to some embodiments described herein, a flexible negative electrode for a lithium battery includes a flexible substrate 110, which may be a current collector comprising copper and having a thickness of 10 μm or less, typically 8 μm or less, advantageously 7 μm or less, particularly 6 μm or less, and especially 5 μm or less. The flexible negative electrode further includes a first layer 120 comprising a silver-carbon (Ag-C) nanocomposite having a thickness of 5 μm or more and / or 15 μm or less, and a second layer 130 comprising a Group IV lithium alloy nanoparticle as described and disclosed herein having a thickness of 5 μm or more and / or 15 μm or less.

[0047] FIG. 2 is a process flow diagram summarizing one embodiment of a method 200 for forming an anode structure according to one or more embodiments. In operation 210, group IV nanoparticles are introduced into a mixing vessel assembly. The mixing vessel assembly can be heated. The group IV nanoparticles can include nanoparticles selected from carbon nanoparticles, silicon nanoparticles, germanium nanoparticles, tin nanoparticles, or any combination thereof. In one example, the group IV nanoparticles include germanium nanoparticles. In operation 220, lithium is introduced into the heated mixing vessel assembly. Operations 210 and 220 can be repeated sequentially until a desired amount of each component is present in the heated mixing vessel to form alternating layers of nanoparticles and lithium in the heated mixing vessel assembly. Without being bound by theory, it is believed that the sequential introduction of the group IV nanoparticles and lithium into the mixing vessel assembly provides a more uniform mixture, which reduces the alloying time. In some embodiments, operation 220 is performed before operation 210. In operation 230, the Group IV nanoparticles are alloyed with lithium to form pre-lithiated Group IV alloy type nanoparticles. In operation 240, the pre-lithiated Group IV alloy type nanoparticles are deposited on a substrate. Alternatively, the pre-lithiated Group IV alloy type nanoparticles can be mixed with other components to form a slurry.

[0048] 3 is a schematic diagram of a system 300 for forming an anode structure according to one or more embodiments. The system is configured to generate and optionally deposit pre-lithiated Group IV alloy type nanoparticles. The system 300 includes a lithium source module 310, a Group IV nanoparticle source module 320, and a mixing vessel assembly 330. The lithium source module 310 and the Group IV nanoparticle source module 320 can be fluidly coupled to the mixing vessel assembly 330. The lithium source module 310 provides lithium to the mixing vessel assembly 330, and the Group IV nanoparticle source module 320 provides Group IV nanoparticles to the mixing vessel assembly 330. The mixing vessel assembly 330 can heat the lithium and the Group IV nanoparticles to generate the pre-lithiated Group IV alloy type nanoparticles.

[0049] In some embodiments, the system 300 further includes a deposition source module 340. The deposition source module 340 is configured to deposit pre-lithiated Group IV alloy type nanoparticles onto a substrate. In some embodiments, the mixing vessel assembly 330 is fluidly coupled to the deposition source module 340. The mixing vessel assembly 330 supplies the pre-lithiated Group IV alloy type nanoparticles to the deposition source module 340. In other embodiments, the pre-lithiated Group IV alloy type nanoparticles can be generated in the mixing vessel assembly 330 and stored in the deposition source module 340 or another deposition source for later use.

[0050] The system 300 may further include a system controller 350. The system controller 350 may control various aspects of the system 300. The system controller 350 facilitates the control and automation of the system 300 and may include a central processing unit (CPU), memory, and supporting circuitry (or I / O). Software instructions and data may be coded and stored in the memory to instruct the CPU. The system controller 350 may communicate with one or more of the components of the system 300, for example, via a system bus. A program (or computer instructions) readable by the system controller 350 determines which tasks may be performed on the substrate. In some embodiments, the program is software readable by the system controller 350, which may include code for mixing various components of the prelithiated Group IV alloy type nanoparticles. Although the system controller 350 is illustrated as a single system controller, it is understood that multiple system controllers may be used in the aspects described herein.

[0051] 4 is a schematic diagram of an example of a lithium source system according to one or more embodiments. The lithium source system 400 can be used in the lithium source module 310 to supply lithium to a mixing container assembly, such as the mixing container assembly 330. The lithium source system 400 includes a lithium supply tank 410 for holding and supplying lithium. The lithium supply tank 410 contains a supply of lithium 420. In one example, the supply of lithium 420 is in liquid form. In another example, the supply of lithium 420 is in solid form that is heated above the melting point of lithium to form liquid lithium prior to delivery to the mixing container assembly 330.

[0052] The lithium supply tank 410 includes a temperature controller 430, e.g., a heat source, for melting the lithium to form the molten phase lithium 420. In one embodiment, the lithium supply tank 410 is positioned on a temperature controller 430 adapted to control the temperature of the lithium supply tank 410. For example, in at least one embodiment where the lithium is supplied in solid form, the temperature controller 430 applies sufficient heat to the solid lithium to melt it. Any suitable temperature controller sufficiently operable to control the temperature of the lithium supply tank 410 can be used for the temperature controller 430. Examples of temperature controllers include a heat exchanger, a resistive heater, a temperature controlled jacket, or any combination thereof.

[0053] In some embodiments, the temperature control device 430 is a temperature control jacket operable to control the temperature of the lithium supply tank 410. The temperature control jacket can surround and be thermally connected to the lithium supply tank 410. In one example, the temperature control jacket is configured as a double-walled cylindrical structure defining a passage between the walls for conducting a heated or cooled liquid. A thermocouple can be coupled to at least one of the temperature control jacket and / or the lithium supply tank 410 to provide feedback to a controller, e.g., the system controller 350. A flow control mechanism can be provided to vary the flow rate of the heated or cooled liquid through the temperature control jacket based on temperature readings received through feedback from the thermocouple. Other heating sources can be used for the lithium supply tank 410. For example, a resistive heater can be thermally coupled to or in thermal contact with the lithium supply tank 410 to control the temperature of the lithium supply tank 410.

[0054] In some embodiments, the lithium source system 400 further includes an inert gas supply 440 fluidly coupled to the lithium supply tank 410. In the embodiment shown in Figure 4, the inert gas supply 440 is fluidly coupled to the lithium supply tank 410 via a first conduit 442, e.g., an air hose or pipe. During operation, a pump evacuates air from the lithium supply tank 410, which air can be replaced with an inert gas, e.g., argon gas, from the inert gas supply 440 to provide a controlled, non-reactive environment for the lithium metal in the lithium supply tank 410.

[0055] In some embodiments, the lithium source system 400 further includes a pressure regulator 444, e.g., a control valve. The pressure regulator 444 is configured to receive the inert gas from the inert gas supply 440 via the first conduit 442. The pressure regulator 444 operates to mitigate pressure spikes from the inert gas supply 440. The pressure regulator 444 can be defined by a target pressure regulator pressure. In some embodiments, the pressure regulator 444 is configured to provide the inert gas to the first conduit 442 at a pressure equal to or less than the target pressure regulator pressure. In other embodiments, the pressure regulator 444 is configured to provide the inert gas to the first conduit 442 at a pressure equal to or greater than the target pressure regulator pressure. In some embodiments, the pressure regulator 444 is a two-stage pressure regulator. In some embodiments, the pressure regulator 444 is electrically coupled to or in electrical communication with the system controller 350. The system controller 350 may be configured to instruct the pressure regulator 444 to change the pressure of the target pressure regulator. In this manner, the system controller 350 is configured to control the pressure regulator 444.

[0056] In some embodiments, the lithium source system 400 further includes a mass flow meter 448, e.g., a mass flow sensor, mass air flow (MAF) sensor, or MAF meter. The mass flow meter 448 is configured to determine (e.g., sense, obtain, etc.) a mass flow rate of the inert gas passing through the mass flow meter 448. The mass flow meter 448 is electrically coupled to or in electrical communication with the system controller 350. The system controller 350 is configured to receive the mass flow rate from the mass flow meter 448. The mass flow rate may be provided by the system controller 350 for comparison to a target mass flow rate. The system controller 350 may command the inert gas supply 440 and / or the pressure regulator 444 based on the mass flow rate received from the mass flow meter 448. In some embodiments, the mass flow meter 448 is a 1,000 liters per minute mass flow meter, e.g., the mass flow meter 448 may measure a mass flow rate up to 1,000 liters per minute.

[0057] In some embodiments, the first conduit 442 provides the inert gas to a gauge 446, e.g., a pressure gauge. The gauge 446 is configured to determine the pressure of the inert gas in the first conduit 442 and thus the pressure of the inert gas in the first conduit 442 at a location downstream of the pressure regulator 444. In some embodiments, the gauge 446 is configured to determine a gauge pressure (e.g., a pressure relative to atmospheric pressure, etc.) and includes an atmospheric input (not shown). The gauge 446 is electrically coupled to or in electrical communication with the system controller 350. The system controller 350 is configured to receive the pressure of the air in the first conduit 442 at a location downstream of the pressure regulator 444 from the gauge 446. The system controller 350 can command the inert gas supply 440, the mass flow meter 448, and / or the pressure regulator 444 based on the pressure received from the gauge 446.

[0058] In some embodiments, the lithium supply tank 410 is fluidly coupled to the mixing vessel assembly 330 via a second conduit 450. The second conduit 450 conveys molten lithium from the lithium supply tank 410 to the mixing vessel assembly 330. The lithium source system 400 may further include one or more shut-off valves 452 to control the flow of molten lithium from the lithium supply tank 410 to the mixing vessel assembly 330. The one or more shut-off valves 452 may be ceramic lined valves. The system controller 350 may command the one or more shut-off valves 452.

[0059] In some embodiments, the second conduit 450 further includes a filter assembly 454 operable to remove impurities from the stream of molten lithium flowing through the second conduit 450. The filter assembly 454 can be of any design and / or material suitable for removing unwanted quantities of solid and gaseous contaminants (e.g., lithium nitride and lithium oxide) from the molten lithium. In one example, the filter assembly 454 includes a skimmer device operable to remove solid contaminants from the surface of the liquid lithium.

[0060] In some embodiments, the second conduit 450 further includes a temperature controller 456. The temperature controller 456 maintains the lithium in liquid form within the second conduit 450. Any suitable temperature controller operable to control the temperature of the lithium within the second conduit 450 can be used as the temperature controller 430. In one example, the temperature controller 456 is a temperature control jacket. The temperature control jacket can surround and be thermally connected to the second conduit 450. In one example, the temperature control jacket is configured as a double-walled cylindrical structure defining a passage between the walls for conducting a heated or cooled liquid. A thermocouple can be coupled to at least one of the temperature control jacket and / or the second conduit 450 to provide feedback to a controller, for example, the system controller 350. A flow control mechanism can be provided to control the temperature of the second conduit 450. The flow control mechanism varies the flow rate of heated or cooled liquid through the temperature control jacket based on temperature readings received through feedback from the thermocouple.

[0061] 5 is a schematic diagram of another example of a lithium source system 500 according to one or more embodiments. The lithium source system 500 can be used in a lithium source module 310 to supply solid lithium, e.g., lithium powder, to a mixing container assembly 330. The lithium source system 500 includes a container 510 for holding and supplying lithium. The lithium source system 500 further includes a delivery conduit 560 for delivering lithium 520 to a mixing container assembly, e.g., the mixing container assembly 330. The delivery conduit 560 is fluidly coupled at a first end 562 to an inert gas supply 570 and at a second end 564 to the mixing container assembly 330.

[0062] The container 510 contains a supply of lithium 520. In one embodiment, the lithium 520 is in powder form. The container 510 has a conical hopper portion 530. The conical hopper portion 530 has a cone angle and forms a lower section of the container 510. In some embodiments, a load cell device 540 can be used on the container 510 to provide continuous monitoring of the weight of the lithium powder in the container. The load cell device 540 is electrically coupled to or in electrical communication with the system controller 350. The conical hopper portion 530 is connected to a discharge opening 552. The discharge opening 552 is provided with a discharge valve 554 for selectively opening or closing the discharge opening 552. The discharge opening 552 is connected to a discharge conduit 556. The discharge conduit 556 is provided with a shutoff valve 558. Discharge conduit 556 is connected to a conical section 566, which is connected to a delivery conduit 560. In operation, a quantity of solid lithium can be metered from the conical hopper section 530 into the discharge conduit 556 by closing shutoff valve 558 and opening discharge valve 554. This quantity of solid lithium can be delivered into the delivery conduit 560 by opening shutoff valve 558. The quantity of solid lithium can be delivered into the mixing vessel assembly 330 via the delivery conduit 560 using an inert gas supplied from an inert gas supply 570.

[0063] 6 is a schematic diagram of an example of a group IV nanoparticle source system 600 according to one or more embodiments. The group IV nanoparticle source system 600 can be used in a group IV nanoparticle source module 320 to supply group IV nanoparticles, e.g., germanium or silicon nanoparticles, to a mixing vessel assembly, e.g., mixing vessel assembly 330. The group IV nanoparticle source system 600 is configured for non-thermal plasma synthesis of group IV nanoparticles. The group IV nanoparticle source system 600 includes a group IV nanoparticle precursor supply assembly 610 for supplying gaseous group IV nanoparticle precursors and a plasma chamber 620 for converting the group IV nanoparticle precursors to group IV nanoparticles. The group IV nanoparticle source system 600 further includes a delivery conduit 650 for delivering the group IV nanoparticles from the plasma chamber 620 to the mixing vessel assembly, e.g., mixing vessel assembly 330.

[0064] In some embodiments, the Group IV nanoparticle precursor supply assembly 610 includes an aqueous solution bubbler 612 fluidly coupled to a push gas source or a first carrier gas source 614. In the embodiment shown in FIG. 6, the first carrier gas source 614 is fluidly coupled to the aqueous solution bubbler 612 via a first conduit 616, e.g., an air hose or pipe. The first conduit 616 can include a mass flow meter 618, e.g., a mass flow sensor, an air flow (MAF) sensor, or a MAF meter. The mass flow meter 618 is configured to determine (e.g., sense, obtain, etc.) a mass flow rate of the carrier gas passing through the mass flow meter 618. The mass flow meter 618 is electrically coupled to or in electrical communication with the system controller 350. The first conduit 616 can further include one or more valves to control the flow rate of the push gas into the aqueous solution bubbler 612. The push gas or first carrier gas source 614 can include an inert gas, such as argon gas.

[0065] The aqueous solution bubbler 612 typically contains a liquid group IV nanoparticle precursor 613. The liquid group IV nanoparticle precursor 613 can be a group IV chloride. The group IV chloride can be, for example, GeCl4, CCl4, SnCl4, or SiCl4. In one example, the group IV chloride is a GeCl4 solution. In one example, a push gas, such as argon, provided by a first carrier gas source 614 is bubbled through the liquid group IV nanoparticle precursor 613 in the aqueous solution bubbler 612. The process gas control subroutine can adjust the flow of the push gas, the pressure in the aqueous solution bubbler 612, and the temperature of the aqueous solution bubbler 612 to obtain the desired group IV nanoparticle precursor gas. The desired process gas flow rates can be communicated to the process gas control subroutine as process parameters. The process gas control subroutine can be executed by the system controller 350.

[0066] The Group IV nanoparticle precursor gas can be delivered from the aqueous solution bubbler 612 to the plasma chamber 620 via a second conduit 619, such as an air hose or pipe. The second conduit 619 can be fluidly coupled to a gas distribution assembly 622 of the plasma chamber 620.

[0067] The plasma chamber 620 includes a chamber body 624. The gas distribution assembly 622 and the chamber body 624 surround a plasma region 626. The plasma chamber 620 includes an upper plasma generating electrode 628 and a lower plasma generating electrode 630 for generating a processing plasma in a central portion of the plasma region by transmitting power from an RF power source 633 to the central portion while gas is present in the plasma region 626. The plasma chamber 620 may further include at least one set of magnets for maintaining a boundary layer plasma at a boundary portion of the plasma region 626 around the processing plasma.

[0068] The gas distribution assembly 622 may be fluidly coupled to a hydrogen gas source 632 via a third conduit 634, e.g., an air hose or pipe. Hydrogen gas is delivered from the hydrogen gas source 632 via the gas distribution assembly 622 into the plasma region 626. Without being bound by theory, it is believed that the hydrogen gas removes chlorine resulting from the decomposition of Group IV chlorides. Without the hydrogen gas, Group IV nanoparticles would not be formed. The third conduit 634 may further include a mass flow meter 636 and one or more valves to control the flow rate of hydrogen gas into the plasma region 626.

[0069] In some embodiments, the gas distribution assembly 622 can be fluidly coupled to an inert gas source, e.g., first carrier gas source 614, via a fourth conduit 640, e.g., an air hose or pipe. An inert gas, e.g., argon, is delivered from the first carrier gas source 614 through the gas distribution assembly 622 into the plasma region 626. The inert gas can be used as a plasma-forming gas. The fourth conduit 640 can further include a mass flow meter 642 and one or more valves to control the flow rate of the inert gas into the plasma region 626.

[0070] The plasma chamber 620 is fluidly coupled to a mixing vessel, e.g., the mixing vessel assembly 330. The Group IV nanoparticle source system 600 further includes a delivery conduit 650 for delivering the Group IV nanoparticles from the plasma chamber 620 to the mixing vessel, e.g., the mixing vessel assembly 330.

[0071] In some embodiments, the Group IV nanoparticle source system 600 further includes a pressure regulator 654, e.g., a control valve. The pressure regulator 654 is configured to receive the fluidized powder from the plasma chamber 620 via the delivery conduit 650. The pressure regulator 654 operates to mitigate pressure spikes from the fluidized powder flowing from the plasma chamber 620 through the delivery conduit 650. The pressure regulator 654 can be defined by a target pressure regulator pressure. In some embodiments, the pressure regulator 654 is configured to provide the fluidized powder to the delivery conduit 650 at a pressure equal to or less than the target pressure regulator pressure. In other embodiments, the pressure regulator 654 is configured to provide the fluidized powder to the delivery conduit 650 at a pressure equal to or greater than the target pressure regulator pressure. In some embodiments, the pressure regulator 654 is a two-stage pressure regulator. In some embodiments, the pressure regulator 654 is electrically coupled to or in electrical communication with the system controller 350. The system controller 350 may be configured to instruct the pressure regulator 654 to change the pressure of the target pressure regulator. In this manner, the system controller 350 is configured to control the pressure regulator 654.

[0072] In some embodiments, the Group IV nanoparticle source system 600 further includes a gauge 652, e.g., a pressure gauge. The delivery conduit 650 provides the fluidized powder to the gauge 652. The gauge 652 is configured to determine the pressure of the fluidized powder in the delivery conduit 650 and thus the pressure of the fluidized powder in the delivery conduit 650 at a location upstream of the pressure regulator 654. In some embodiments, the gauge 652 is configured to determine a gauge pressure (e.g., a pressure relative to atmospheric pressure, etc.) and includes an atmospheric input (not shown). The gauge 652 can be electrically coupled to or in electrical communication with the system controller 350. The system controller 350 is configured to receive the pressure of the fluidized powder in the delivery conduit 650 at a location upstream of the pressure regulator 654 from the gauge 652. The system controller 350 can command the plasma chamber 620 and / or the pressure regulator 654 based on the pressure received from the gauge 652.

[0073] In some embodiments, the Group IV nanoparticle source system 600 further includes a pump 660, e.g., a vacuum pump, for removal of exhaust gases from the Group IV nanoparticle source system 600. The pump 660 is fluidly coupled to the delivery conduit 650. The pump 660 can be fluidly coupled to the delivery conduit 650 downstream of the pressure regulator 654 and upstream of the mixing vessel assembly 330.

[0074] In some embodiments, the Group IV nanoparticle source system 600 further includes an inert gas source 670. The inert gas source 670 provides a carrier gas for delivering the fluidized powder to the mixing vessel assembly 330. The inert gas source 670 is fluidly coupled to the delivery conduit 650. The inert gas source 670 can be fluidly coupled to the delivery conduit 650 downstream of the pressure regulator 654 and / or pump 660 and upstream of the mixing vessel assembly 330.

[0075] In operation, group IV nanoparticles are generated by dissociation of group IV chlorides in the plasma formed in the plasma region 626 and subsequent clustering of group IV chloride radicals. In one embodiment, argon and hydrogen are used as buffer gases and are supplied to the plasma region 626 by the first carrier gas source 614 and the hydrogen gas source 632, respectively. GeCl4 is supplied to the plasma region 626 by the aqueous solution bubbler 612. Radio frequency power is applied to the upper plasma generating electrode 628 and the lower plasma generating electrode 630 by the RF power source to generate a processing plasma in the plasma region 626 while the gas is present in the plasma region 626. Germanium nanoparticles are generated by dissociation of GeCl4 in the plasma formed in the plasma region 626 and subsequent clustering of GeCl4 radicals. The germanium nanoparticles are then delivered to the mixing vessel assembly 330 via the delivery conduit 650.

[0076] 7 is a schematic diagram of another example of a group IV nanoparticle source system 700 according to one or more embodiments. The group IV nanoparticle source system 700 can be used in the group IV nanoparticle source module 320 to supply group IV nanoparticles, e.g., germanium, tin, carbon, or silicon nanoparticles, to a mixing vessel assembly, e.g., mixing vessel assembly 330. The group IV nanoparticle source system 700 is configured to apply a shear force to a group IV material to generate group IV nanoparticles. The group IV nanoparticle source system 700 includes a hopper assembly 710 for holding and supplying the group IV nanoparticles. The hopper assembly 710 includes a vessel body 712 for holding and supplying the group IV nanoparticles. The group IV nanoparticle source system 700 further includes a delivery conduit 760 for delivering the group IV nanoparticles to the mixing vessel assembly 330. The delivery conduit 760 is fluidly coupled to an inert gas supply 770 at a first end 762 and to the mixing vessel assembly 330 at a second end 764.

[0077] In some embodiments shown in FIG. 7, the group IV nanoparticle source system 700 further includes a ball mill container 780 fluidly coupled to the vessel body 712 via a supply conduit 782. The ball mill container 780 contains a group IV material 784. The ball mill container 780 is configured to apply a shear force to the group IV material 784 to generate group IV nanoparticles 720. The mechanical shear force is applied to the group IV material 784 by placing the group IV material 784 and ball mill balls in the ball mill container 780 and rotating the ball mill container 780 for a predetermined time to allow the ball mill balls to generate friction with the walls of the ball mill container 780 and to rotate about their own axis. In one example, the rotation of the ball mill container 780 to apply the mechanical shear force to the group IV material 784 is performed in a non-oxidizing atmosphere. In another example, the rotation of the ball mill container 780 to apply the mechanical shear force to the group IV material 784 is performed in an oxidizing atmosphere.

[0078] The group IV material 784 can be an artificially prepared group IV material or a natural group IV material. The group IV material used in this embodiment can include plate-type group IV material, powder-type group IV material, and chunk-type group IV material, and is not limited to any particular shape or size.

[0079] The material of the ball mill balls is not particularly limited, but ball mill balls made of polyimide material may be used to effectively apply frictional force and prevent excessive damage to the group IV material 784. The size of the ball mill balls may be appropriately selected in consideration of the shear force applied to the group IV material 784. For example, the diameter of the ball mill balls may range from about 3 mm to about 50 mm. If the size of the ball mill balls is less than 3 mm, the mass of the ball mill balls is relatively small, and therefore the mechanical shear force applied to the group IV material 784 may be smaller than the desired value. In contrast, if the size of the ball mill balls is greater than 50 mm, excessively high shear force or impact may be applied to the group IV material 784, and therefore the group IV material 784 may be damaged.

[0080] The mixing ratio of the group IV material 784 with the ball mill balls can be appropriately controlled. For example, the group IV material 784 and the ball mill balls can be combined such that the total weight of the ball mill balls is greater than the total weight of the group IV material 784 to apply mechanical shear force throughout the group IV material 784.

[0081] The ball mill container 780 can then be rotated to allow ball mill balls introduced into the ball mill container 780 to apply mechanical shear forces to the Group IV material 784 .

[0082] In one embodiment, the inside of the ball mill container 780 can be maintained at a non-oxidizing atmosphere during the ball milling process to prevent oxidation of the group IV material 784. For example, the inside of the ball mill container can be maintained at a non-oxidizing atmosphere by being maintained at a vacuum and then purged with argon gas to prevent oxidation of the group IV material 784.

[0083] The container body 712 contains a supply of group IV nanoparticles 720. In one embodiment, the group IV nanoparticles 720 are in powder form. The container body 712 has a conical hopper portion 730. The conical hopper portion 730 has a cone angle and forms a lower section of the container body 712. In some embodiments, a load cell device 740 can be used on the container body 712 to provide continuous monitoring of the weight of the group IV nanoparticles 720 in the container body 712. The load cell device 740 is electrically coupled to or in electrical communication with the system controller 350. The conical hopper portion 730 is connected to an outlet opening 752. The outlet opening 752 is provided with an outlet valve 754 for selectively opening or closing the outlet opening 752. The outlet opening 752 is connected to an outlet conduit 756. The discharge conduit 756 is provided with a shutoff valve 758. The discharge conduit 756 is coupled to a conical portion 766, which is connected to a delivery conduit 760. In operation, a quantity of Group IV nanoparticles 720 can be metered from the conical hopper portion 730 into the discharge conduit 756 by closing the shutoff valve 758 and opening the discharge valve 754. This quantity of Group IV nanoparticles 720 can be delivered into the delivery conduit 760 by opening the shutoff valve 758. The quantity of Group IV nanoparticles 720 can be delivered into the mixing vessel assembly 330 using an inert gas provided from an inert gas supply 770.

[0084] 8 is a schematic diagram of a mixing vessel assembly 800 according to one or more embodiments. The mixing vessel assembly 800 can be used as the mixing vessel assembly 330 shown in FIG. 3. The mixing vessel assembly 800 is configured to mix group IV nanoparticles with lithium to form lithiated group IV alloy type nanoparticles. The mixing vessel assembly 800 can be a rotary type mixer. The mixing vessel assembly 800 includes a mixing vessel container 810 for holding and mixing the group IV nanoparticles with lithium.

[0085] A stirring member 820 is positioned within the mixing vessel container 810. Any suitable stirring member that provides sufficient mixing, e.g., uniform mixing of the group IV nanoparticles and lithium, can be used. In one embodiment, the stirring member 820 used comprises a first impeller 822 or one dispersing device of rotor / stator type with variable rotation speed. The variable speed allows adjusting the tip speed of the first impeller 822 and thus the mixing of the group IV nanoparticles and lithium. The first impeller 822 is coupled with a shaft 824. The stirring member 820 can further comprise a second impeller with pumping action for large axial displacement to reduce mixing times. In some embodiments, the first impeller and the second impeller are both positioned on the shaft 824.

[0086] The mixing vessel assembly 800 further includes a first delivery conduit 832 for delivering lithium from the lithium source module 310 to the mixing vessel container 810. The mixing vessel assembly 800 further includes a second delivery conduit 834 for delivering Group IV nanoparticles from the Group IV nanoparticle source module 320 to the mixing vessel container 810. The delivery conduit 760 is fluidly coupled at a first end 762 to the inert gas supply 770 and at a second end 764 to the mixing vessel assembly 330. The mixing vessel assembly 800 further includes an output conduit 836 for delivering the lithiated Group IV alloy type nanoparticles from the mixing vessel assembly 800 to the deposition source module 340. An outlet valve 838 can be positioned along the output conduit 836 to control the flow of the lithiated Group IV alloy type nanoparticles.

[0087] The mixing vessel assembly 800 includes a temperature controller 840, e.g., a heat source for alloying the lithium with the group IV nanoparticles. The temperature controller 840 may surround and be in thermal communication with the mixing vessel container 810. In one or more embodiments, the mixing vessel container 810 is positioned on the temperature controller 840 adapted to control the temperature of the mixing vessel container 810. For example, the temperature controller 840 applies heat sufficient to alloy the lithium with the group IV nanoparticles. Any suitable temperature controller sufficient to control the temperature of the mixing vessel container 810 may be used for the temperature controller 840. Examples of temperature controllers include a heat exchanger, a resistive heater, a temperature controlled jacket, or any combination thereof.

[0088] In another embodiment, the temperature control device 840 is a temperature control jacket operable to control the temperature of the mixing vessel container 810. The temperature control jacket can surround and be thermally connected to the mixing vessel container 810. In one embodiment, the temperature control jacket can be configured as a double-walled cylindrical structure defining a passage between the walls for conducting heated or cooled liquid. A thermocouple can be coupled to at least one of the temperature control jacket and / or the vessel container 810 to provide feedback to a controller, e.g., the system controller 350. A flow control mechanism can be provided to vary the flow rate of the heated or cooled liquid through the temperature control jacket based on temperature readings received through feedback from the thermocouple. Other heating sources can be used for the mixing vessel container 810. For example, a resistive heater can be thermally coupled to the mixing vessel container 810 or in thermal contact with the lithium supply tank 410 to control the temperature of the mixing vessel container 810.

[0089] The mixing vessel assembly 800 may further include an insulator 850. The insulator may surround and be in thermal communication with the temperature control device 840.

[0090] In some embodiments, the mixing vessel assembly 800 may further include one or more load cells 860a, 860b (collectively 860). The one or more load cells 860 may be secured to the mixing vessel container 810 by load cell mounts 862a, 862b (collectively 862) or another suitable means. The one or more load cells 860 are designed to measure a force applied thereto and provide an output value (signal) representative of the measured force. This output value may then be utilized directly as the force on the load cell 860, or the output value may be converted using various known component parameters to reflect the resulting torque about the shaft 824. The output value may then be used as an input signal to control functions of the system, such as, for example, the mixing speed, the delivery of additional lithium and Group IV nanoparticles into the mixing vessel container 810, and / or the delivery of lithiated Group IV alloy type nanoparticles from the mixing vessel container 810.

[0091] In some embodiments, the lithium and group IV nanoparticles are delivered sequentially to the mixing vessel container 810. In one example, a first layer of lithium is delivered into the mixing vessel container 810 via a first delivery conduit 832, and a second layer of group IV nanoparticles is deposited on the first layer of lithium via a second delivery conduit 834. These operations can be repeated sequentially until a target amount of alternating layers of lithium metal and group IV nanoparticles is present in the mixing vessel container 810. Without being bound by theory, the inventors have found that the alternating layers of lithium metal and group IV nanoparticles become more uniform when mixed.

[0092] In some embodiments, lithium-alloy nanoparticles, e.g., Li22Ge5, are obtained from a metallurgical alloying process in which molten lithium and group IV nanoparticles are introduced into a mixing vessel container 810. The group IV nanoparticles are obtained from a non-thermal plasma synthesis of a group IV-halide source. To reduce the alloying time, both lithium and group IV nanoparticles are added to the sequencing layer. After the process is completed, the particles can be mixed in a slurry form with, e.g., carbon black, a binder, and a solvent, and cast using conventional slurry-based methods, e.g., slot-die coating. Alternatively, the group IV nanoparticles serve as a stable lithium-bearing agent and are applied onto a graphite-coated current collector using conventional powder coating methods and calendering, optionally with heating for adhesion.

[0093] Figure 9 is a schematic diagram of an example of a deposition source module 900 according to one or more embodiments. The deposition source module 900 can be used as the deposition source module 340 shown in Figure 3. The deposition source module 900 is configured for depositing lithiated Group IV alloy type nanoparticles onto a flexible substrate, such as an anode structure 910. In one example, the anode structure 910 includes a current collector 920 on which a graphite-containing anode 930 is formed.

[0094] In some embodiments, the deposition source module 900 includes a shifter body 940. The shifter body 940 includes a shifter body open top end 942 and a shifter body bottom end 944 that terminates in a shifter 946. In one example, the shifter body 940 is cone-shaped. The shifter body 940 defines a shifter body interior for holding the lithiated Group IV alloy type nanoparticles. The shifter 946 has a number of openings at the shifter body bottom end 944. The number of openings regulates the amount of material that can be deposited on the anode structure 910. The material to be dispensed is stored within the interior space defined by the shifter body 940.

[0095] The deposition source module 900 may further include a hopper assembly 950 for storing and delivering lithiated Group IV alloyed nanoparticles, such as lithiated silicon or germanium nanoparticles, to the shifter body 940. The hopper assembly 950 includes a container body 952 for holding and delivering the lithiated Group IV alloy type nanoparticles. The deposition source module 900 may further include a delivery conduit 960 for delivering the lithiated Group IV alloy type nanoparticles to the shifter body 940. The delivery conduit 960 is fluidly coupled at a first end 962 to an inert gas supply 970 and at a second end 964 to the mixing container assembly 330.

[0096] The container body 952 contains a supply of lithiated Group IV alloy type nanoparticles 954. The container body 952 has a conical hopper section 956. The conical hopper section 956 has a cone angle and forms a lower section of the container body 952. In some embodiments, a load cell device 958 is used on the container body 952. The load cell device 958 can provide continuous monitoring of the weight of the lithiated Group IV alloy type nanoparticles 954 in the container body 952. The load cell device 958 is electrically coupled to or in electrical communication with the system controller 350. The conical hopper section 956 is connected to an outlet opening 972. The outlet opening 972 is provided with an outlet valve 974 for selectively opening or closing the outlet opening 972. The outlet opening 972 is connected to an outlet conduit 976. In one embodiment, the discharge conduit 976 has a conical shape. In operation, a quantity of lithiated Group IV alloy type nanoparticles 954 can be metered from the conical hopper portion 956 into the discharge conduit 976 by opening the discharge valve 974. The lithiated Group IV nanoparticles can be delivered into the delivery conduit 960 by opening the discharge valve. A quantity of the lithiated Group IV alloy type nanoparticles 954 can be delivered to the shifter body 940 using an inert gas provided from an inert gas supply 970.

[0097] The deposition source module 900 can further include a set of calender rollers 980 for activating the lithiated Group IV nanoparticles. The calender rollers 980 can be temperature controlled.

[0098] Figure 10 is a schematic diagram of another example of a deposition source system 1000 according to one or more embodiments. The deposition source system 1000 can be used as the deposition source module 340 shown in Figure 3. The deposition source system 1000 is configured to deposit lithiated Group IV alloy type nanoparticles onto a flexible substrate, such as an anode structure 1010. In one example, the anode structure 1010 includes a current collector 1020 on which a graphite-containing anode 1030 is formed.

[0099] In some embodiments, the deposition source system 1000 includes a processing module 1040 that defines a vacuum processing environment 1042 according to one or more embodiments. The deposition source system 1000 can be a flexible substrate coating system, such as a SMARTWEB® system manufactured by Applied Materials, adapted for manufacturing lithium-containing anode film stacks according to embodiments described herein. The deposition source system 1000 can be used to manufacture prelithiated anode structures, particularly for film stacks for prelithiated anode structures. The deposition source system 1000 is configured as a roll-to-roll system that includes the processing module 1040. The deposition source system 1000 can further include an unwinding module and a winding module. In some embodiments, the processing module 1040 includes multiple processing modules or chambers arranged in sequence, each of which is configured to perform one processing operation on a continuous sheet of material, such as a current collector 1020 or a web of material.

[0100] In some embodiments, the processing chambers can be arranged radially around the coating drum 1055. The coating drum 1055 can be temperature controlled. Although the processing module 1040 has a single deposition source 1060, the processing module 1040 can be divided into two or more submodules, each including a separate deposition source. In one or more embodiments shown in FIG. 10, the deposition source 1060 is an electrospray gun 1064. In one example, the electrospray gun 1064 is a triboelectric powder spray gun. In another example, the electrospray gun 1064 is a corona spray gun. The electrospray gun 1064 or head charges the lithiated Group IV alloy-type nanoparticles, and the charged lithiated Group IV nanoparticles 1066 are emitted from a nozzle 1062 of the electrospray gun 1064. The charged lithiated Group IV nanoparticles 1066 move toward the anode structure 1010 carried by the coating drum 1055. The electrospray gun 1064 can be fluidly coupled to a source of inert gas 1070 .

[0101] The deposition source system 1000 may further include a hopper assembly for storing and delivering lithiated Group IV alloyed nanoparticles, such as lithiated silicon or germanium nanoparticles, to the electrospray gun 1064. The hopper assembly may be the hopper assembly 950 described in FIG. 9. The deposition source system 1000 may further include a delivery conduit 1080 for delivering the lithiated Group IV alloyed nanoparticles from the hopper assembly to the electrospray gun 1064. The delivery conduit 1080 is fluidly coupled at a first end 1082 to the inert gas supply 970 and at a second end 1084 to the electrospray gun 1064.

[0102] FIG. 11 is a process flow diagram 1100 summarizing one or more embodiments of a method for forming a silver-carbon (Ag-C) nanocomposite according to one or more embodiments. FIG. 12 is a schematic diagram of a system 1200 for forming a silver-carbon (Ag-C) nanocomposite according to one or more embodiments. The method illustrated in the process flow diagram 1100 of FIG. 11 can be implemented on the system 1200 illustrated in FIG. 12. The silver-carbon (Ag-C) nanocomposite can be a lithium metal-free silver-carbon ("Ag-C") nanocomposite. The silver-carbon nanocomposite can be deposited using silver (PVD) and carbon (PECVD) co-deposition to create an anode coating that can tune the Li nucleation energy to minimize dendrites. The deposition of silver can be performed by a PVD process. The deposition of carbon can be performed by chemical vapor deposition, for example, a plasma enhanced chemical vapor deposition (PECVD) process.

[0103] In operation 1110, a silver-carbon nanocomposite is formed on a substrate. The silver-carbon nanocomposite can function as an electrode, e.g., an anode. The silver-carbon nanocomposite can be a silver-carbon nanocomposite layer 1204. The substrate can be substrate 1202. Substrate 1202 can be a continuous flexible substrate, e.g., continuous flexible substrate 110 depicted in FIG. 1. In one embodiment, substrate 1202 includes a conductive material, typically a metal, e.g., copper (Cu) or nickel (Ni).

[0104] Operation 1110 includes operation 1120. In operation 1120, silver and carbon, e.g., amorphous carbon, are co-deposited to form a silver-carbon nanocomposite layer, e.g., silver-carbon nanocomposite layer 1204. Silver can be deposited using a silver (Ag) source 1210 and carbon can be deposited using a carbon source 1220.

[0105] The silver (Ag) source 1210 can be a sputtering source. Examples of sputtering sources include magnetron sputtering sources, DC sputtering sources, such as DC sputtering guns, AC sputtering sources, pulsed sputtering sources, radio frequency (RF) sputtering sources, or medium frequency (MF) sputtering sources. For example, MF sputtering at frequencies ranging from 5 kHz to 100 kHz, such as 30 kHz to 50 kHz, can be provided. As used herein, "magnetron sputtering" refers to sputtering performed using a magnet assembly, i.e., a unit capable of generating a magnetic field. Typically, such a magnet assembly includes a permanent magnet. This permanent magnet is typically disposed inside the rotating target or coupled to a planar target such that free electrons are trapped within the generated magnetic field that is generated below the rotating target surface. Such a magnet assembly may be disposed coupled to a planar cathode.

[0106] The carbon source 1220 can be a plasma enhanced chemical vapor deposition (PECVD) source. Precursor gases that can be used to form the carbon portion of the silver-carbon nanocomposite include hydrocarbon gases and hydrogen. In one embodiment, the carbon of the silver-carbon nanocomposite is an amorphous carbon film. The hydrocarbon gas can include hydrogen compounds having the general formula CxHy, where x ranges from 1 to 10 and y ranges from 2 to 22. For example, methane (CH4), acetylene (C2H2), propylene (C3H6), propyne (C3H4), propane (C3H8), butane (C4H 10), butylene (C4H8), butadiene (C4H6), pentane, pentene, pentadiene, cyclopentane, cyclopentadiene, benzene, toluene, alpha terpinene, phenol, cymene, norbornadiene, and combinations thereof may be used as the hydrocarbon compound. Similarly, various gases, such as hydrogen (H2), nitrogen (N2), ammonia (NH3), among others, or combinations thereof, may be added to the gas mixture as needed. Argon (Ar), helium (He), and nitrogen (N2) may be used to control the density and deposition rate of the carbon fraction.

[0107] In some embodiments, during deposition of the carbon portion, the substrate is maintained at a temperature of about 200 degrees Celsius to about 700 degrees Celsius, for example, about 250 degrees Celsius to about 350 degrees Celsius, for example, about 300 degrees Celsius. In some embodiments, RF power levels of about 20 W to about 1,600 W, for example, about 1,000 W. RF power can be provided at a frequency of about 0.01 MHz to about 300 MHz, for example, 13.56 MHz. In some embodiments, RF power can be provided to a gas distribution assembly or "showerhead" electrode in the carbon source 1220. In some embodiments, RF power can be provided at mixed frequencies, for example, a high frequency of about 13.56 MHz and a low frequency of about 350 kHz. RF power can be cycled or pulsed, continuous or discontinuous.

[0108] Optionally, in operation 1130, a lithium layer is deposited on the silicon-carbon nanocomposite. The lithium layer can function as a pre-lithiated layer to replenish lithium loss from the first cycle capacity loss of the silicon-carbon nanocomposite. The lithium layer can be lithium layer 1206 shown in FIG. 12. The lithium layer can be deposited by a lithium source, such as lithium source 1230. The lithium layer 1206 can be a thin film of lithium metal (e.g., 20 microns or less, about 1 micron to about 20 microns, about 2 microns to about 10 microns). The lithium source 1230 can include an evaporation system, such as an electron beam evaporator, a thermal evaporator, or a thin film delivery system (including a large area pattern printing system, such as a gravure printing system), a lamination system, or a slot die deposition system.

[0109] 13 is a schematic diagram of another deposition source system 1300 for forming a silver-carbon (Ag-C) nanocomposite according to one or more embodiments. The deposition source system 1300 is configured to deposit a film stack including a silver-carbon (Ag-C) nanocomposite layer 1310 and an optional lithium layer 1320 onto a substrate 1330, such as a flexible continuous substrate or web of material. In one example, the substrate 1330 is a current collector as described and disclosed herein. In another example, the substrate 1330 includes a current collector having an anode formed thereon.

[0110] In some embodiments, the deposition source system 1300 includes a processing module 1340 that defines a vacuum processing environment 1342. The deposition source system 1300 can be a flexible substrate coating system, such as a SMARTWEB® system manufactured by Applied Materials, adapted for manufacturing anode film stacks according to embodiments described herein. The deposition source system 1300 can be used for manufacturing silver-carbon anode structures, particularly for prelithiated anode structures. The deposition source system 1300 is configured as a roll-to-roll system that includes the processing module 1340. The deposition source system 1300 can further include an unwinding module for supplying the substrate 1330 and a winding module for collecting the prelithiated silver-carbon anode structure. In some embodiments, the processing module 1340 includes multiple processing modules or subchambers arranged in sequence, each of which is configured to perform one processing operation on a continuous sheet of material, such as the substrate 1330 or a web of material.

[0111] In some embodiments, the processing module 1340 includes multiple sequentially arranged processing modules, or a first subchamber 1350 and a second subchamber 1360, each of which is configured to perform one processing operation on the substrate 1330. In one example, as shown in FIG. 13, the first subchamber 1350 and the second subchamber 1360 are radially arranged around a coating drum 1370. The coating drum 1370 can be temperature controlled. The first subchamber 1350 and the second subchamber 1360 are separated by partition walls 1352a-1352c (collectively 1352). For example, the first subchamber 1350 is defined by partition walls 1352a and 1352b, and the second subchamber 1360 is defined by partition walls 1352b and 1352c. In one embodiment, the first subchamber 1350 and the second subchamber 1360 are closed except for a narrow, arcuate gap facing the coating drum 1370, defined by a partition wall 1352. A plasma region 1352 may be generated and / or contained within the first subchamber 1350.

[0112] The first sub-chamber 1350 and the second sub-chamber 1360 typically include one or more deposition sources 1354, 1356, and 1362. In general, the one or more deposition sources 1354, 1356, and 1362 described and disclosed herein include sputtering sources and additional sources that can be selected from the group of CVD sources, PECVD sources, and various evaporation sources. In some embodiments, the deposition source 1354 is a sputtering source configured to deposit silver, e.g., the silver portion of the silver-carbon (Ag-C) nanocomposite layer 1310. Examples of sputtering sources include magnetron sputtering sources, DC sputtering sources, AC sputtering sources, pulsed sputtering sources, radio frequency (RF) sputtering sources, or mid-frequency (MF) sputtering sources. For example, MF sputtering at a frequency ranging from 5 kHz to 100 kHz, e.g., 30 kHz to 50 kHz, can be provided. "Magnetron sputtering" as used herein refers to sputtering performed using a magnet assembly, i.e., a unit capable of generating a magnetic field. Typically, such a magnet assembly includes a permanent magnet. This permanent magnet is typically disposed inside a rotating target or coupled to a planar target such that free electrons are trapped within the generated magnetic field that is generated below the rotating target surface. Such a magnet assembly may also be disposed in conjunction with a planar cathode.

[0113] In some embodiments, the second deposition source 1356 is a chemical vapor deposition source configured to deposit carbon, e.g., the carbon portion of the silver-carbon (Ag-C) nanocomposite layer 1310. In one example, the second deposition source 1356 is a plasma enhanced chemical vapor deposition (PECVD) source. The second deposition source 1356 can be fluidly coupled to a gas panel 1358 configured to deliver a precursor gas to the second deposition source 1356. In some embodiments, the gas panel 1358 includes a hydrocarbon gas source, an inert gas source, and a hydrogen gas source. In one example, the hydrocarbon gas source includes methane, the inert gas source includes argon, and the hydrogen gas source includes hydrogen.

[0114] One or more of the deposition sources 1354, 1356, and 1362 can include one or more evaporation sources. In some embodiments, the third deposition source 1362 is an evaporation source fluidly coupled to the lithium source 1364. The third deposition source 1362 can be configured to deposit lithium, e.g., the lithium layer 1320. Examples of evaporation sources include thermal evaporation sources and electron beam evaporation sources. In one example, the evaporation source is a thermal evaporation source configured to deposit lithium. The material to be deposited (e.g., lithium) can be provided in a crucible. For example, the lithium can be evaporated by a thermal evaporation technique or by an electron beam evaporation technique.

[0115] The first sub-chamber 1350 includes a first deposition source 1354 and a second deposition source 1356. In the embodiment shown in FIG. 1, the first deposition source 1354 is a DC sputtering gun and the second deposition source 1356 is an electrode showerhead. The first deposition source 1354 can be configured to deposit silver by a sputtering process. The second deposition source 1356 can be configured to deposit a carbon material, e.g., an amorphous carbon material, by a PECVD process. The first deposition source 1354 and the second deposition source 1356 can be configured to co-deposit silver and carbon to form a silver-carbon (Ag-C) nanocomposite layer 1310. The second sub-chamber 1360 includes a third deposition source 1362. The third deposition source 1362 can be an evaporation source, e.g., a thermal evaporation source. The third deposition source 1362 is configured to deposit a lithium layer 1320 onto the silver-carbon (Ag—C) nanocomposite layer 1310 .

[0116] The first subchamber 1350 and the second subchamber 1360 may include any suitable structure, configuration, arrangement, and / or components that enable the deposition source system 1300 to deposit a silver-carbon nanocomposite film stack according to an embodiment. For example, but not limited to, the first subchamber 1350 and the second subchamber 1360 may include a suitable deposition system including a coating source, a power source, individual pressure control devices, a deposition control system, and a temperature control device. In some embodiments, the subchambers are provided with individual gas sources. As described and disclosed herein, the first subchamber 1350 and the second subchamber 1360 are typically separated from each other to provide good gas isolation. The deposition source system 1300 described herein is not limited in the number of subchambers. For example, the deposition source system 1300 may include, but is not limited to, 3, 6, or 12 subchambers.

[0117] 14 is a schematic diagram of a system 1400 for forming a silver-carbon (Ag-C) containing slurry 1470 according to one or more embodiments. The system 1400 includes a mixing vessel assembly 1410. The mixing vessel assembly 1410 is configured to mix various components to form a silver-carbon (Ag-C) containing slurry 1470. The silver-carbon (Ag-C) containing slurry 1470 can be used to form a silver-carbon nanocomposite. The mixing vessel assembly 1410 can be a rotary type mixer. In some embodiments, the mixing vessel assembly 1410 is the mixing vessel assembly 800 shown in FIG. 8.

[0118] The system 1400 further includes a silver nanoparticle source 1420 operable to supply silver nanoparticles to the mixing vessel assembly 1410. The silver nanoparticle source 1420 is fluidly coupled to the mixing vessel assembly 1410 via a fluid delivery conduit 1422. The fluid delivery conduit 1422 is fluidly coupled to the silver nanoparticle source 1420 at a first end 1424 and to the mixing vessel assembly 1410 at a second end 1426. In some embodiments, the silver nanoparticle source 1420 includes a spray pyrolysis system 1500 for forming silver nanoparticles. The spray pyrolysis system 1500 is described in further detail in FIG.

[0119] The system 1400 further includes a carbon additive source container 1430 for supplying a carbon additive 1432 to the mixing container assembly 1410. The carbon additive source container 1430 is fluidly coupled to the mixing container assembly 1410 via a fluid delivery conduit 1434. In some embodiments, the carbon additive is selected from the group of graphite, graphene hard carbon, carbon black, carbon coated silicon, or any combination thereof. In some embodiments, the carbon additive source container 1430 is a hopper assembly. In one example, the carbon additive source is similar to the hopper assembly 710 shown in FIG. 7 or the hopper assembly 950 shown in FIG. 9. The fluid delivery conduit 1434 is fluidly coupled to an inert gas supply 1436 at a first end 1437 and to the mixing container assembly 1410 at a second end 1438. The inert gas supply 1436 is positioned upstream relative to the carbon additive source container 1430. An inert gas, for example argon, supplied from an inert gas supply 1436 can be used to deliver a desired amount of carbon additive 1432 into the mixing vessel assembly 1410 .

[0120] The system 1400 can further include a binder source container 1440 for supplying a binder 1442 to the mixing container assembly 1410. The binder source container 1440 is fluidly coupled to the mixing container assembly 1410 via a fluid delivery conduit 1444. In some embodiments, the binder is a styrene-butadiene rubber, an acrylated styrene-butadiene rubber, an acrylonitrile copolymer, an acrylonitrile-butadiene rubber, a nitrile butadiene rubber, an acrylonitrile-styrene-butadiene copolymer, an acrylic rubber, a butyl rubber, a fluororubber, a polytetrafluoroethylene, a polyethylene, a polypropylene, an ethylene / propylene copolymer, a polybutadiene, a polyethylene oxide, a chlorosulfonated polyethylene, a polyvinylpyrrolidone, a polyvinylpyridine, a polyvinyl alcohol, a polyvinyl acetate, a polyepichlorohydrin, a polyphosphazene, a polyacrylonitrile, a polystyrene, a latex, a styrene-butadiene rubber ... , acrylic resins, phenolic resins, epoxy resins, carboxymethyl cellulose, hydroxypropyl cellulose, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethyl cellulose, cyanoethyl sucrose, polyesters, polyamides, polyethers, polyimides, polycarboxylates, polycarboxylic acids, polyacrylic acids, polyacrylates, polymethacrylic acids, polymethacrylates, polyacrylamides, polyurethanes, fluorinated polymers, chlorinated polymers, salts of alginic acid, polyvinylidene fluoride, poly(vinylidene fluoride)-hexafluoropropene, or combinations thereof. In some embodiments, the binder source container 1440 is a hopper assembly. In one example, the binder source container 1440 is similar to the hopper assembly 710 shown in FIG. 7 or the hopper assembly 950 shown in FIG. 9. The fluid delivery conduit 1444 is fluidly coupled at a first end 1447 to an inert gas supply 1446 and at a second end 1448 to the mixing vessel assembly 1410. The inert gas supply 1446 is positioned upstream relative to the binder source vessel 1440. An inert gas, e.g., argon, supplied from the inert gas supply 1446 can be used to deliver a desired amount of binder 1442 into the mixing vessel assembly 1410.

[0121] The system 1400 may further include a solvent source container 1450 for supplying a solvent 1452 to the mixing container assembly 1410. The solvent 1452 is fluidly coupled to the mixing container assembly 1410 via a fluid delivery conduit 1454. In some embodiments, the solvent 1452 is selected from the group of N-methyl-2-pyrrolidone, dimethylformamide, dimethylsulfoxide, acetonitrile, butylene carbonate, propylene carbonate, ethyl bromide, tetrahydrofuran, dimethyl carbonate, diethyl carbonate, ethyl methyl, carbonate methyl propyl carbonate, ethylene carbonate, water, pure water, deionized water, distilled water, ethanol, isopropanol, methanol, acetone, n-propanol, t-butanol, or any combination thereof. The fluid delivery conduit 1454 is fluidly coupled to the solvent source container 1450 at a first end 1457 and to the mixing container assembly 1410 at a second end 1458 .

[0122] The silver-carbon (Ag-C) containing slurry 1470 is prepared by mixing the anode active material with other materials, such as a carbon additive and a binder, in a solvent. The mixing process aims to achieve a uniform dispersion of the particles of the anode active material, the carbon additive, and the binder in the solvent. In operation, the silver nanoparticles, the carbon additive, the binder, and / or the solvent are sequentially introduced into the mixing vessel assembly 1410. The mixing vessel assembly 1410 can be heated. The introduction of the silver nanoparticles, the carbon additive, the binder, and / or the solvent can be repeated sequentially to form alternating layers of the silver nanoparticles, the carbon additive, the binder, and / or the solvent in the mixing vessel assembly until a desired amount of each component is present in the mixing vessel assembly. Without being bound by theory, it is believed that the sequential introduction of the slurry forming components into the mixing vessel assembly 1410 provides a more uniform slurry mixture.

[0123] 15 is a schematic diagram of a spray pyrolysis system 1500 according to one or more embodiments. The spray pyrolysis system includes an ultrasonic spray deposition nozzle 1504. The spray pyrolysis system 1500 includes a silver solution source container 1510, e.g., a silver nitrate (AgNO3) solution. The silver solution source container 1510 is fluidly coupled to the ultrasonic spray deposition nozzle 1504 via a fluid delivery line 1512. The spray pyrolysis system 1500 may further include an inert gas source 1520, e.g., an argon gas source. The inert gas source 1520 is fluidly coupled to the ultrasonic spray deposition nozzle 1504 via a fluid delivery line 1522. The spray pyrolysis system 1500 further includes a heating element 1530, which may be positioned downstream from the ultrasonic spray deposition nozzle 1504. The heating element 1530 defines a nanoparticle formation region 1532 where silver nanoparticles are formed. In operation, silver nitrate is delivered from a silver solution source container 1510 to the ultrasonic spray deposition nozzle 1504. Ultrasonic frequencies are applied to the silver nitrate solution to generate atomized droplets of the silver nitrate solution. The atomized droplets are entrained with a controlled jet of air as a carrier gas from an inert gas source 1520. The atomized droplets are delivered and heated to a nanoparticle formation region 1532 where the atomized droplets are thermally converted to silver nanoparticles.

[0124] Embodiments may include one or more of the following potential advantages. In one aspect, methods and systems are provided for forming lithium anode devices. In one embodiment, methods and systems are provided for forming prelithiated Group IV alloy type nanoparticles (NPs), e.g., Li-Z (Z is Ge, Si, or Sn). In another embodiment, methods and systems are provided for synthesizing Group IV nanoparticles and alloying the Group IV nanoparticles with lithium. The Group IV nanoparticles can be made on demand and premixed with the anode material or coated onto the anode material. In yet another embodiment, methods and systems are provided for forming lithium metal-free silver-carbon ("Ag-C") nanocomposites (NCs). In yet another embodiment, methods are provided for making anode coatings that utilize silver (PVD) and carbon (PECVD) co-deposition to allow for tuning of lithium nucleation energy to minimize dendrite formation.

[0125] All of the embodiments and functional operations described herein can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structural means disclosed herein and their structural equivalents, or in combinations thereof. The embodiments described herein can be implemented as one or more non-transitory computer program products, such as one or more computer programs tangibly embodied in a machine-readable storage device, for execution by or to control the operation of a data processing apparatus, such as a programmable processor, a computer, or multiple processors or computers.

[0126] The processes and logic flows described herein may be implemented by one or more programmable processors executing one or more computer programs that perform functions by operating on input data and generating output. The processes and logic flows may also be implemented by, and an apparatus may be implemented as, special purpose logic circuitry, such as an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit).

[0127] The term "data processing apparatus" encompasses all apparatus, devices and machines for processing data, including by way of example a programmable processor, computer, or multiple processors or computers. In addition to hardware, an apparatus may include code that creates the execution environment for the computer program in question, such as code constituting a processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of these. Processors suitable for the execution of computer programs include by way of example both general purpose and special purpose microprocessors, and any one or more processors of any kind of digital computer.

[0128] Computer-readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media, and memory devices, including, by way of example, semiconductor memory devices, such as EPROM, EEPROM, and flash memory devices, magnetic disks, such as internal hard disks or removable disks, magneto-optical disks, and CD-ROM and DVD-ROM disks. The processor and memory may be supplemented by, or incorporated in, dedicated logic circuitry.

[0129] Embodiments of the present disclosure further relate to any one or more of the following Examples 1-34.

[0130] Example 1. A method of making lithiated Group IV nanoparticles comprising introducing a layer of Group IV nanoparticles into a heated mixing vessel, introducing a layer comprising lithium into the heated mixing vessel, sequentially repeating introducing a layer of Group IV nanoparticles and a layer comprising lithium into the heated mixing vessel, and alloying the Group IV nanoparticles with lithium to form lithiated Group IV nanoparticles.

[0131] Example 2. The method of Example 1, wherein the Group IV nanoparticles are formed from a non-thermal plasma synthesis process.

[0132] Example 3. The method of Example 1 or 2, wherein the lithiated Group IV nanoparticles are air-stable prelithiated reagents.

[0133] Example 4. The method of any one of Examples 1-3, wherein introducing the layer of Group IV nanoparticles into the heated mixing vessel comprises providing molten lithium into the heated mixing vessel.

[0134] Example 5. The method of any one of Examples 1-4, wherein introducing the layer of Group IV nanoparticles into the heated mixing vessel comprises providing lithium powder into the heated mixing vessel.

[0135] Example 6. The method of any one of Examples 1-5, further comprising applying lithiated Group IV nanoparticles to a graphite anode to form a prelithiated graphite anode.

[0136] Example 7. The method of any one of Examples 1-6, wherein applying lithiated Group IV nanoparticles to a graphite anode to form a prelithiated graphite anode comprises an industrial sifter-feeder process.

[0137] Example 8. The method of any one of Examples 1-7, wherein applying lithiated Group IV nanoparticles to a graphite anode to form a prelithiated graphite anode comprises an electrospray process.

[0138] Example 9. The method of any one of Examples 1-8, wherein the Group IV nanoparticles are selected from silicon nanoparticles, germanium nanoparticles, tin nanoparticles, carbon nanoparticles, or any combination thereof.

[0139] Example 10. The method of any one of Examples 1-9, wherein the heated mixing vessel is a rotating planetary mixer.

[0140] Example 11. The method of any one of Examples 1-10, further comprising mixing lithiated Group IV nanoparticles to form a slurry.

[0141] Example 12. The method of any one of Examples 1-11, wherein mixing the lithiated Group IV nanoparticles to form a slurry includes mixing the lithiated Group IV nanoparticles with a conductive additive, a binder, a solvent, or any combination thereof.

[0142] Example 13. The method of any one of Examples 1-12, further comprising casting the slurry onto an anode structure to form a prelithiated alloy anode.

[0143] Example 14. A system for forming an anode structure comprising a lithium source module operable to supply lithium, a Group IV nanoparticle source module operable to supply Group IV nanoparticles, and a mixing vessel assembly, wherein the mixing vessel assembly is capable of heating the lithium and Group IV nanoparticles to produce prelithiated Group IV alloy type nanoparticles.

[0144] Example 15. The system of Example 14, further comprising a deposition source module operable to deposit prelithiated Group IV alloy type nanoparticles onto the substrate.

[0145] Example 16. The system of example 14 or 15, wherein the deposition source module includes a shifter body, a hopper assembly, and a delivery conduit fluidly coupling the hopper assembly with the shifter body.

[0146] Example 17. A system described in any one of Examples 14 to 16, wherein the deposition source module includes a deposition module defining a processing environment, a coating drum positioned within the processing environment and operable to transport a flexible substrate, and an electrospray gun positioned within the processing environment and operable to deposit prelithiated Group IV alloy type nanoparticles on the flexible substrate.

[0147] Example 18. The system of any one of Examples 14-17, wherein the electrospray gun is a triboelectric powder spray gun or a corona spray gun.

[0148] Example 19. The system of any one of Examples 14-18, further comprising a hopper assembly operable to store and deliver lithiated Group IV alloyed nanoparticles to the electrospray gun.

[0149] Example 20. A method of forming an anode structure comprising forming a silver-carbon (Ag-C) nanocomposite on a current collector web, comprising sputtering silver onto the current collector web simultaneously with plasma enhanced chemical vapor deposition of amorphous carbon to form a silver-carbon nanocomposite on the current collector.

[0150] Example 21. The method of example 20, further comprising depositing a layer of lithium over the silver-carbon nanocomposite.

[0151] Example 22. The method of example 20 or 21, wherein depositing a layer of lithium on the silver-carbon nanocomposite comprises thermally evaporating lithium.

[0152] Example 23. The method of any one of Examples 20-22, wherein sputtering silver onto the current collector is performed using a DC sputtering gun.

[0153] Example 24. A flexible substrate coating system including: an unwinding module housing a feed reel capable of providing a continuous sheet of flexible material; a take-up module housing a take-up reel capable of storing the continuous sheet of flexible material; a processing module arranged downstream of the unwinding module, the processing module including a plurality of sequentially arranged subchambers, each configured to perform one or more processing operations on the continuous sheet of flexible material; and a coating drum capable of guiding the continuous sheet of flexible material through the plurality of subchambers along a traveling direction, the subchambers being arranged radially around the coating drum, and a first of the plurality of subchambers including a first deposition source operable to deposit silver and a second deposition source operable to deposit carbon.

[0154] Example 25. The flexible substrate coating system of Example 24, wherein the first deposition source is a physical vapor deposition (PVD) source and the second deposition source is a plasma enhanced chemical vapor deposition (PECVD) source.

[0155] Example 26. A flexible substrate coating system as described in Example 24 or 25, wherein the physical vapor deposition source comprises a DC sputtering gun and the PECVD source comprises an electrode showerhead.

[0156] Example 27. The flexible substrate coating system of any one of Examples 24-26, wherein the first subchamber is defined by a subchamber body having an edge shield positioned thereon.

[0157] Example 28. A flexible substrate coating system as described in any one of Examples 24-27, wherein the edge shield has one or more apertures that define a pattern of evaporated material to be deposited on the continuous sheet of flexible material.

[0158] Example 29. The flexible substrate coating system of any one of Examples 24-28, further comprising a second subchamber containing a thermal evaporation source.

[0159] Example 30. The flexible substrate coating system of any one of Examples 24-29, wherein the thermal evaporation source is configured to deposit lithium metal.

[0160] Example 31. A method of forming a lithium-free silver-carbon (Ag-C) based slurry, comprising forming silver nanoparticles via a spray pyrolysis process, and combining the silver nanoparticles with a conductive additive, a binder, and a solvent in a heated mixing vessel to form a lithium-free silver-carbon (Ag-C) based slurry.

[0161] Example 32. The method of example 31, wherein the conductive additive is selected from the group of graphite, graphene hard carbon, carbon black, carbon coated silicon, or any combination thereof.

[0162] Example 33. The binder is selected from the group consisting of styrene-butadiene rubber, acrylated styrene-butadiene rubber, acrylonitrile copolymer, acrylonitrile-butadiene rubber, nitrile butadiene rubber, acrylonitrile-styrene-butadiene copolymer, acrylic rubber, butyl rubber, fluororubber, polytetrafluoroethylene, polyethylene, polypropylene, ethylene / propylene copolymer, polybutadiene, polyethylene oxide, chlorosulfonated polyethylene, polyvinylpyrrolidone, polyvinylpyridine, polyvinyl alcohol, polyvinyl acetate, polyepichlorohydrin, polyphosphazene, polyacrylonitrile, polystyrene, latex, acrylic resin, and phenolic resin. 33. The method of claim 31 or 32, wherein the polymerizable compound is selected from the group consisting of polyvinylidene fluoride, polyvinylidene fluoride, poly(vinylidene fluoride)-hexafluoropropene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropene ...

[0163] Example 34. The method of any one of Examples 31-33, wherein the solvent is selected from N-methyl-2-pyrrolidone, dimethylformamide, dimethylsulfoxide, acetonitrile, butylene carbonate, propylene carbonate, ethyl bromide, tetrahydrofuran, dimethyl carbonate, diethyl carbonate, ethyl methyl, carbonate methyl propyl carbonate, ethylene carbonate, water, pure water, deionized water, distilled water, ethanol, isopropanol, methanol, acetone, n-propanol, t-butanol, or any combination thereof.

[0164] Although the above description is directed to embodiments of the present disclosure, other and further embodiments may be devised without departing from the basic scope of the present disclosure, the scope of the present disclosure being determined by the claims. All documents described herein, including any priority documents and / or test procedures, are incorporated herein by reference to the extent that they do not contradict the contents of the present disclosure. As is apparent from the summary and specific embodiments above, forms of the present disclosure have been shown and described, but various modifications can be made without departing from the spirit and scope of the present disclosure. Thus, it is not intended that the present disclosure be limited by the forms of the present disclosure. Similarly, the word "comprising" is considered synonymous with the words "including" or "having" as interpreted in the United States law. Similarly, whenever a composition, element, or group of elements precedes the transitional phrase "comprising," it is assumed that the same composition or group of elements has the transitional phrase "consisting essentially of," "consisting of," "selected from the group consisting of," or "is," following the recitation of the composition, element, or group, and vice versa. When introducing elements of the disclosure or exemplary aspects or one or more embodiments thereof, the articles "a," "an," "the," and "said" are intended to mean that there are one or more of the elements.

[0165] Some embodiments and features have been described using a set of upper numerical limits and a set of lower numerical limits. It is to be understood that ranges including any combination of two values ​​are envisioned, for example, any lower value with any upper value, any two lower values, and / or any two upper values, unless otherwise indicated. One or more claims are set forth with specific lower limits, upper limits, and ranges.

Claims

1. introducing a layer of Group IV nanoparticles into a heated mixing vessel; introducing a lithium-containing layer into said heated mixing vessel; repeating sequentially introducing layers of the Group IV nanoparticles and the lithium-containing layer into the heated mixing vessel; and alloying the Group IV nanoparticles with the lithium to form lithiated Group IV nanoparticles.

1. A method of making lithiated Group IV nanoparticles comprising:

2. The method of claim 1 , wherein the Group IV nanoparticles are formed from a non-thermal plasma synthesis process.

3. 10. The method of claim 1, wherein the lithiated Group IV nanoparticles are air-stable prelithiated reagents.

4. 10. The method of claim 1, wherein introducing the layer of Group IV nanoparticles into the heated mixing vessel further comprises providing molten lithium into the heated mixing vessel.

5. 10. The method of claim 1, wherein introducing the layer of Group IV nanoparticles into the heated mixing vessel further comprises providing lithium powder into the heated mixing vessel.

6. 10. The method of claim 1, further comprising applying the lithiated Group IV nanoparticles to a graphite anode to form a prelithiated graphite anode.

7. 7. The method of claim 6, wherein applying the lithiated Group IV nanoparticles to a graphite anode to form a prelithiated graphite anode comprises an industrial sifter-feeder process.

8. 7. The method of claim 6, wherein applying the lithiated Group IV nanoparticles to a graphite anode to form a prelithiated graphite anode comprises an electrospray process.

9. 2. The method of claim 1, wherein the Group IV nanoparticles are selected from silicon nanoparticles, germanium nanoparticles, tin nanoparticles, carbon nanoparticles, or any combination thereof.

10. The method of claim 1 , wherein the heated mixing vessel is a rotating planetary mixer.

11. The method of claim 10 , further comprising mixing the lithiated Group IV nanoparticles to form a slurry.

12. 12. The method of claim 11 , wherein mixing the lithiated Group IV nanoparticles to form the slurry further comprises mixing the lithiated Group IV nanoparticles with a conductive additive, a binder, a solvent, or any combination thereof.

13. 13. The method of claim 12, further comprising casting the slurry onto an anode structure to form a prelithiated alloy type anode.

14. a lithium source module operable to supply lithium; a Group IV nanoparticle source module operable to supply Group IV nanoparticles; and a mixing vessel assembly capable of heating the lithium and the Group IV nanoparticles to produce prelithiated Group IV alloy-type nanoparticles; 1. A system for forming an anode structure comprising:

15. 15. The system of claim 14, further comprising a deposition source module operable to deposit the prelithiated Group IV alloy type nanoparticles onto a substrate.

16. the deposition source module comprising: Shifter body, A hopper assembly, and A delivery conduit fluidly connecting the hopper assembly with the shifter body. The system of claim 15 , comprising:

17. the deposition source module comprising: a deposition module defining a processing environment; a coating drum positioned within the processing environment and operable to transport a flexible substrate; and an electrospray gun positioned within the processing environment and operable to deposit the prelithiated Group IV alloy-type nanoparticles onto the flexible substrate; The system of claim 15 , comprising:

18. 20. The system of claim 17, wherein the electrospray gun is a triboelectric powder spray gun or a corona spray gun.

19. 20. The system of claim 18, further comprising a hopper assembly operable to store and deliver the prelithiated Group IV alloy type nanoparticles to the electrospray gun.

20. a payout module housing a feed reel capable of providing a continuous sheet of flexible material; a take-up module housing a take-up reel capable of storing the continuous sheet of flexible material; and A processing module disposed downstream of the payout module, a plurality of sequentially arranged sub-chambers, each configured to perform one or more processing operations on the continuous sheet of flexible material; and a coating drum capable of guiding said continuous sheet of flexible material through said plurality of sub-chambers along a direction of travel; the subchambers being radially arranged around the coating drum, a first subchamber of the plurality of subchambers comprising: a first deposition source operable to deposit silver; a second deposition source operable to deposit carbon; A processing module including 1. A flexible substrate coating system comprising:

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