ARTIFICIAL SOLID ELECTROLYTE INTERFACE CAP LAYER FOR AN ANODE IN A Li S BATTERY SYSTEM, AND METHOD OF FABRICATING A LITHIUM (Li) ANODE

Abstract

This disclosure provides a battery pack including a cathode and an anode positioned opposite the cathode. The anode includes a mixed artificial solid-electrolyte mesophase (A-SEI) layer encapsulating the anode. The mixed A-SEI layer includes: a first active component; a second active component disposed on the first active component; and a plurality of carbon-containing aggregates interwoven throughout the first and second active components and configured to inhibit the growth of Li dendrite structures from the anode toward the cathode. A spacer is located between the anode and the cathode. The cathode includes a porous, carbon-based structure configured to expand in the presence of polysulfide (PS) shuttles within one or more portions of the battery pack. An electrolyte is dispersed between and in contact with the anode and cathode. The plurality of carbon-containing aggregates may include polymers, including cross-linked polymeric networks.

Description

Technical Field

[0001] Invention Field This disclosure generally relates to suppressing the formation of lithium (Li) dendritic structures on lithium metal electrodes (anodes), and more specifically to enabling Li-ion and lithium-sulfur (Li₂S) battery packs to have stability and long lifespan. Prior Technology

[0002] Background of the Invention Lithium-ion (Li-ion), lithium (Li) metal, and lithium-sulfur (Li₂S) battery packs are considered promising power sources for demanding applications such as electric vehicles (EVs), hybrid electric vehicles (HEVs), and modern portable electronic devices such as laptops and smartphones. Compared to other alkali metals, Li metal offers the highest specific capacity relative to any other metal or intercalating metal compound used as an anode material. Therefore, Li metal battery packs (such as Li metal battery packs with solid Li metal foil anodes) exhibit significantly higher energy and power densities than lithium-ion battery packs (traditionally characterized by graphite anodes with intercalated Li ions). However, due to the highly reactive and explosive nature of elemental Li when exposed to extreme forces, such as those experienced during a vehicle collision, cycle stability and safety issues remain major factors hindering the widespread commercialization of Li metal or Li₂S battery packs with solid Li metal foil anodes, particularly for applications in EVs, HEVs, and microelectronic devices. Furthermore, the specific cycle stability and safety issues of Li metal and LiS rechargeable battery packs are mainly related to the high tendency of Li to form dendritic structures. These dendritic structures extend across the battery pack from the anode to the cathode during repeated charge-discharge cycles or overcharging, and contribute to internal electrical short circuits and thermal runaway.

[0003] Conventional efforts to address problems related to dendritic growth during battery pack operation include implementing multilayer spacers comprising porous membranes and electroactive polymeric materials contained within the spacer material. In addition to spacer improvements, an intermediate electrode or layer has been proposed, positioned between the anode and cathode and spaced apart from both by glass fiber paper spacers. This intermediate electrode comprises carbon or graphite material disposed on the surface of the spacer and acts as a low-capacity cathode for rapidly discharging any Li dendritic crystals in contact with the getter layer. Surface layers (such as polynuclear aromatics and polyethylene oxides) capable of transferring metal ions from the metal anode to the electrolyte and back have also been proposed. These surface layers are also electronically conductive to uniformly attract ions back to the metal anode during electrodeposition. It has also been shown that using multilayer metal oxide films as spacers with small pores can prevent internal short circuits, allowing Li ions to pass through and suppressing dendritic growth. The first thin-film coating on the anode and the second thin-film coating on the cathode can also effectively prevent dendritic crystal formation, both of which are permeable to lithium ions. The first thin film may contain macrocyclic compounds, aromatic hydrocarbons, fluoropolymers, glassy metal oxides, cross-linked polymers, or conductive powder dispersions. Nevertheless, the dendritic crystal prevention mechanism of these films remains to be clearly explained. Protective coatings for Li anodes, such as glassy surfaces like LiI-Li3PO4-P2S5, can be obtained from plasma-assisted deposition. Despite at least these and other previous efforts, rechargeable Li metal battery packs or LiS battery packs equipped with solid metal Li anodes have not yet achieved reliable commercial success. Therefore, there is a need for simpler, more cost-effective, and easier-to-implement methods to prevent internal short circuits and thermal runaway problems induced by Li metal dendritic crystal formation in Li metal battery packs and other rechargeable battery packs. Summary of the Invention

[0004] Invention Summary This summary is provided to introduce, in a simplified form, selected concepts further described below in the embodiments. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter.

[0005] One innovative embodiment of the subject matter described in this disclosure can be implemented as a lithium-sulfur (Li₂S) battery pack, comprising a cathode and an anode positioned opposite the cathode. The anode includes a hybrid artificial solid-electrolyte mesophase (A-SEI) layer encapsulating the anode. The hybrid A-SEI layer includes: a first active component; a second active component disposed on the first active component; and a plurality of carbon-containing aggregates interwoven throughout the first and second active components and configured to inhibit the growth of Li dendrite structures from the anode toward the cathode. The cathode may include a porous, carbon-based structure configured to expand in the presence of polysulfide (PS) shuttles within one or more portions of the Li₂S battery pack. The electrolyte may be dispersed between and in contact with the anode and cathode.

[0006] In some embodiments, the multiple carbon-containing aggregates include a polymer comprising a crosslinked polymeric network. The crosslinked polymeric network can be configured to control the amount of contact between the electrolyte and the anode. In some embodiments, a first portion of the crosslinked polymeric network has a first crosslinking density, and a second portion of the crosslinked polymeric network has a second lower crosslinking density different from the first crosslinking density. The gradient can be defined by the crosslinking density of the crosslinked polymeric network spanning the mixed A-SEI layer encapsulating the anode. The crosslinked polymeric network can include any or more monomers or oligomers. The crosslinked polymeric network can be configured to inhibit the dissolution of the mixed A-SEI layer. The crosslinked polymeric network can have defined Li wettability configured to promote Li adhesion to the crosslinked polymeric network. The crosslinked polymeric network can include any or more vinyl, acrylate, methacrylate, or epoxy-based groups. One or more of vinyl, acrylate, or methacrylate groups are combined for curing by one or more of ultraviolet (UV) curing or thermosetting methods. Epoxy-based groups are combined for curing by adding amine or amide groups.

[0007] In some embodiments, the first active component may include a barrier configured to prevent direct contact between the Li metal in the anode and the electrolyte. The barrier may be configured to prevent unstable formation of the A-SEI. The barrier may be configured to prevent electrolyte decomposition. In some samples, a Li layer may be deposited on a second active component, configured to ensure uniform deposition of the Li layer. Spacers may be configured to transport Li ions from the anode to the cathode, and these spacers may be further configured to inhibit the growth of Li dendrites from the anode towards the cathode.

[0008] In some embodiments, the anode further comprises a conductive substrate configured to support the hybrid A-SEI layer. The conductive substrate may include a copper current collector. In some embodiments, the anode comprises a metal foil with a thickness between approximately 70 µm and 130 µm. The metal foil may include a Li layer with a thickness between approximately 15 µm and 50 µm. The hybrid A-SEI layer may be conductive. The hybrid A-SEI layer may be configured to electrochemically stabilize itself during the operational cycling of the LiS battery pack. The hybrid A-SEI layer may include one or more flexure points configured to cyclically expand and contract the volume of the hybrid A-SEI layer during the operational cycling of the LiS battery pack.

[0009] In some embodiments, at least one of the first or second active components includes a passivation layer, which may include an inorganic component, including one or more of Al2O3, LiF, Li2S6, P2S5, Li3N, SiO2, MoS2, Li2S3, LiF, LiN3, Li-metal alloys, Li-Si, Li3PO4, LiI, or Li3PS4. The passivation layer may include cross-linked carboxylates of one or more metals, including acrylates of Zn, Sn, In, Al, Mo, or other metals, methacrylates, and higher analogues. In some embodiments, a plurality of carbon-containing aggregates define a porous structure comprising a plurality of few-layer graphene (FLG) sheets fused together. The plurality of carbon-containing aggregates may include polymers assembled to uniformly bond the plurality of carbon-containing aggregates together. The polymer may include one or more of the following: cross-linked polydimethylsiloxane (PDMS), polystyrene (PS), bis(1-(methacryloxy)ethyl) phosphate, succinate, maleic ester, phthalate or phosphate ester, 2-hydroxyethyl methacrylate as the main adhesive, glycerol dimethacrylate maleic ester, polyethylene glycol (PEO), poly(3,4-ethylenedioxythiophene) (PEDOT), styrene-butadiene rubber (SBR), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), and polyvinylidene fluoride (PVDF).

[0010] In some embodiments, the porous structure includes a carbon material having a folded morphology, which can be configured to shrink the volume of the porous structure associated with the crosslinking of polymers incorporated into multiple carbon-containing aggregates. Simple Explanation of the Diagram

[0011] The details of the subject matter described in this disclosure are set forth in the accompanying drawings and the following description. Other features, aspects, and advantages of the subject matter will become apparent from the description, the drawings, and the scope of the claims.

[0012] Figures 1A to 1E show schematic diagrams of carbon-dominant particles with various defined regions for electrical conduction and ion transport, according to some of the states disclosed herein.

[0013] Figure 1F shows a representative schematic diagram of an intermediate step for reducing sulfur and / or forming polysulfides (PS) according to some implementation schemes.

[0014] Figures 1G and 1H show schematic diagrams of the placement and / or spacing of Li ions in carbon lattices and structures according to some embodiments.

[0015] Figure 2 shows a schematic diagram of a cavity formed according to some embodiments, extending deep into several adjacent stacked FL graphene layers.

[0016] Figure 3 shows a schematic diagram of a multi-layered carbon-based support structure according to some implementation schemes.

[0017] Figure 4A shows a schematic diagram of a structure according to some embodiments, having lithium (Li) metal infused into nanoscale gaps as shown in Figure 3.

[0018] Figure 4B shows a simplified version of the structure shown in Figure 3 of an anode prepared according to some embodiments as a mixed artificial solid-electrolyte intermediate phase (A-SEI) layer with an encapsulated anode.

[0019] Figure 4C shows an example of the preparation of an anode as shown in Figure 4B according to some embodiments, which has been formed by the multilayer carbon-based support structure shown in Figure 3.

[0020] Figure 4D shows a table of various adhesives that can be used to enhance the hybrid A-SEI layers shown in Figures 4B and 4C, according to some embodiments.

[0021] Figure 4E shows examples of mechanical strength enhancing additives for A-SEI according to some embodiments shown in Figures 4B and 4C.

[0022] Figure 4F shows an exemplary formation path of a metal polyacrylate suitable for protecting a Li electrode (such as an anode) according to some embodiments.

[0023] Figure 4G shows an image of an exemplary SnF2 / SBR coating on a comparative Hohsen Li / Cu foil according to some implementation schemes.

[0024] Figure 4H shows a diagram illustrating the specific discharge capacity of an exemplary LiS full-capacity cell according to some embodiments, having a Li anode treated with a LiF / Li-Sn alloy mixed A-SEI, a complete Hohsen Li control foil, and a cathode.

[0025] Figure 4I shows an image of an exemplary Si3N4 / SBR A-SEI coating on a comparative Hohsen Li / Cu foil according to some embodiments.

[0026] Figure 4J shows a graph illustrating the specific discharge capacity of an exemplary Li-S full-capacity cell prepared according to some embodiments, with a Li anode treated with a LiN3 / Li-Si mixed A-SEI and a complete Hohsen Li control.

[0027] Figure 4K shows an image of an exemplary graphite fluoride / SBR A-SEI coating in a comparative Hohsen Li / Cu foil anode according to some embodiments.

[0028] Figure 4L shows a graph illustrating the specific discharge capacity of an exemplary Li-S full-capacity cell prepared according to some embodiments, with a Li anode treated with a LiF / graphite mixed A-SEI, a complete Hohsen Li control, and a cathode.

[0029] Figure 4M is an exemplary schematic diagram of a carbon-containing layer comprising carbon allotropes as a functional anode in a Li-ion or LiS battery pack according to some embodiments. These carbon allotropes, with or without doping or functionalization, have a particle size in the range of 0.01-10 µm and are laminated on top of a lithium sheath current collector foil.

[0030] Figure 4N is an exemplary schematic diagram of a roll-to-roll apparatus prepared according to some embodiments for manufacturing carbon / lithium anodes, which utilizes any compression method such as roll-to-roll lamination and release to transfer a carbon-containing coating from another substrate to a lithium surface.

[0031] Figure 4O is an image of an exemplary protective carbon interface (PCI) implemented in or on an anode, such as the one shown in Figure 4M, according to some embodiments.

[0032] Figure 4P shows a graph of the electrode specific capacity performance of a Li anode protected by a protected carbon interface (PCI) according to some embodiments, compared to a reference pure Li metal electrode, as a function of cycle number.

[0033] Figure 4Q shows a graph of the coulombic efficiency of a Li anode protected by a protected carbon interface (PCI) compared to a reference pure Li metal electrode according to some embodiments, as a function of cycle number.

[0034] Figure 4R shows a graph of the average charging voltage of a Li anode protected by a protected carbon interface (PCI) according to some embodiments, compared to a reference pure Li metal electrode, as a function of the number of cycles.

[0035] Figure 4S shows another graph of the specific capacity performance of a Li anode protected by a protected carbon interface (PCI) according to some embodiments, compared to a nanodiamond layer, a reference pure Li metal electrode, and a non-uniform interface layer, relative to the number of cycles.

[0036] Figure 4T shows an image of a disassembled lithium pouch cell according to some embodiments, showing a high degree of dendritic growth into the spacers, which are represented by the transfer of black moss-like structures.

[0037] Figure 4U shows an illustrative image of a Li anode protected by a carbon-containing layer according to some embodiments, such as the Li anode shown in Figure 4M, which shows the absence of the moss-like black protrusions found in the disassembly of the reference battery shown in Figure 4T, and instead shows only a few spots of the layered LPCI of the adhesive spacers during disassembly.

[0038] Figure 4V shows a schematic diagram of a series of plasma torches positioned sequentially above a roll-to-roll (R2R) processing device according to some embodiments.

[0039] Figure 5 shows a schematic diagram of an exemplary Li-ion or LiS electrochemical cell according to some implementation schemes.

[0040] Figure 6A shows a schematic diagram of incorporating metal powder into carbon particles for Li wetting and impregnation according to some embodiments.

[0041] Figures 6B and 6C show schematic diagrams of a chemically non-reactive system and a chemically reactive system according to some implementation schemes, respectively.

[0042] Figure 7 shows an exemplary method workflow according to some implementation schemes, in which molten Li metal is infiltrated into the void spaces between carbon aggregates.

[0043] Figure 8A shows the equations for the infiltration rate of a carbon-based structure according to some implementation schemes.

[0044] Figures 8B and 8C show non-reactive and reactive systems for wetting Li into carbon structures according to some embodiments.

[0045] Figure 9 shows a flowchart illustrating exemplary operations of lithiation and alloying of carbon-based structures according to some implementation schemes.

[0046] Figure 10A shows a flowchart illustrating an exemplary operation for preparing a carbon-based structure according to some embodiments.

[0047] Figure 10B shows a flowchart illustrating exemplary operations for preparing Li materials according to some implementation schemes.

[0048] Figures 10C to 10P show flowcharts illustrating exemplary operations for manufacturing electrochemical battery electrodes according to some embodiments.

[0049] Figures 11A to 11C show exemplary operations for preparing carbon particles for lithiation according to some embodiments.

[0050] Figure 12 shows a flowchart illustrating an exemplary operation of Li infusion of carbon particles according to some implementation schemes.

[0051] Figure 13 shows a schematic diagram of the anode according to some implementation schemes.

[0052] Figure 14 shows the silicon and carbon anode performance in multiple use cycles according to some implementation schemes.

[0053] Figures 15 and 16 show schematic diagrams related to an ideal cathode assembly of graphene with lithium sulfide (Li2S) nanoparticles dispersed therein, according to some embodiments.

[0054] Figures 17A and 17B show magnified portions of carbon-based particles from Figures 1A to 1F according to some embodiments.

[0055] Figures 18A to 18E are micrographs of carbon particle portions according to some embodiments.

[0056] Figure 19A shows a schematic diagram of a 3D carbon-based cathode according to some implementation schemes.

[0057] Figure 19B shows a schematic diagram of a 3D carbon-based anode according to some implementation schemes.

[0058] Figure 20A shows an exemplary Li₂S electrochemical cell discharge and charge cycle according to some implementation schemes.

[0059] Figures 20B and 20C show battery pack performance graphs for battery packs equipped with carbon electrodes according to some implementation schemes.

[0060] Figure 21 shows the Raman spectra of 3D N-doped FL graphene according to some embodiments.

[0061] Figure 22 shows a schematic diagram of bilayer graphene according to some implementation schemes.

[0062] Figure 23 shows a method for preparing a 3D scaffold-type membrane according to some implementation schemes.

[0063] In each diagram, the same reference numbers and names indicate the same components. Implementation

[0064] Detailed Description of Preferred Embodiments Various forms of novel systems, devices, and methods are described more fully herein with reference to the accompanying drawings. However, the teachings disclosed may be embodied in many different forms and should not be construed as limited to any particular structure or function presented throughout this disclosure. Rather, these forms are provided to make this disclosure thorough and complete, and to fully convey the scope of this disclosure to those skilled in the art.

[0065] Based on the teachings herein, those skilled in the art will understand that the scope of this disclosure is intended to cover any form of the novel systems, apparatuses, and methods disclosed herein, whether or not implemented independently of or in combination with any other form of the invention. For example, an apparatus may be implemented using any number of the forms described herein, or a method may be practiced using any number of the forms described herein. Furthermore, the scope of this invention is intended to cover such apparatuses or methods practiced using structures, functions, or structures and functions other than or different from the various forms of the invention described herein. Any form disclosed herein may be embodied by one or more elements of the claims.

[0066] Although some examples and embodiments are described herein, many variations and arrangements of such examples fall within the scope of this disclosure. While some benefits and advantages of preferred embodiments are mentioned, the scope of this disclosure is not intended to be limited to benefits, uses, or objectives. Rather, the embodiments of this disclosure are intended to be broadly applicable to carbon-based particles that self-nucleate in atmospheric pressure vapor streams of carbonaceous gases such as methane, including multiple conductive three-dimensional (3D) aggregates of graphene sheets comprising void spaces and ion channels defined therein, some of which are illustrated in the figures and the following description of preferred embodiments. The detailed description and figures are illustrative only and not limiting of this disclosure, the scope of which is defined by the appended claims and their equivalents. [definition] [ Li ] [ ion ] [ battery pack ]

[0067] Li-ion battery packs are a type of secondary battery pack, alternatively referred to as rechargeable battery packs. In recent years, this battery pack technology has shown great promise as a power source, enabling the widespread adoption of electric vehicles (EVs) in many applications. Therefore, the development of novel materials for various components of Li-ion battery packs has become a research focus in materials science. Li-ion battery packs power most modern portable devices and appear to have overcome the psychological barrier of large-scale consumer use of such high-energy-density devices for demanding applications such as EVs.

[0068] Regarding operation, in a Li-ion battery pack, Li ions (Li+) migrate from the negative electrode, also known as the anode, during discharge cycles, through an electrolyte that can be in either a liquid or gel phase, to the positive electrode, and return during charge cycles. Conventional Li-ion battery packs may use intercalated Li compounds as forming materials at the positive electrode and graphite at the negative electrode. These battery packs are characterized by their relatively high energy density, measured in mAh / g, lack of "memory effect"—describing the gradual loss of maximum energy capacity when a nickel-cadmium battery pack is repeatedly recharged after only partial discharge—and low self-discharge. Unfortunately, unlike many non-Li conventional battery packs, Li-ion battery packs can present safety hazards due to the highly reactive nature of the element and ions of Li. Li battery packs can deteriorate unexpectedly, including through-breakdown, frictional contact, or even explosion and fire during overcharging. Despite these drawbacks, high-energy-density Li-ion battery packs remain attractive due to their longer lifespan, allowing for several hours between charge cycles, and their longer cycle life, which refers to the current delivery or output performance of a given Li-ion battery pack over multiple repeated charge-discharge cycles (such as partial or total depletion).

[0069] Overall, Li metal remains an ideal material for the negative electrode in rechargeable Li-ion battery packs due to its high theoretical specific capacity (3,860 mAh / g), low density (0.59 g cm⁻³), and low negative electrochemical potential (e.g., -3.040 V) compared to the standard hydrogen electrode. However, problems such as dendritic growth persist, referring to the growth of branching, tree-like structures within the battery pack itself, which can be caused by Li deposits. Dendritic growth from one electrode to contact another can cause serious short-circuit-related safety issues and limited coulombic efficiency, a measure of the charging efficiency of electron transfer within the battery pack during the deposition and stripping operations inherent in Li-ion battery packs. These challenges have previously hindered the application of Li-ion battery packs.

[0070] Safety issues with earlier Li-ion secondary battery packs have spurred the development and improvement of contemporary Li-ion secondary battery packs. These Li-ion battery packs are typically characterized by the use of carbon-containing materials as the anode, including: ● Graphite; ● Amorphous carbon; and ● Graphitized carbon. The first type of carbon-containing materials presented above includes naturally occurring graphite and synthetic or artificial graphite (such as highly oriented pyrolytic graphite HOPG). Any form of graphite may contain intercalated Li, such as Li obtained from a molten Li metal source. The resulting graphite intercalation compound (GIC) can be represented as LixC6, where X is typically less than 1. To limit or otherwise minimize the energy density loss due to Li metal substitution with GIC, X in LixC6 must be maximized and the irreversible capacity loss (Qir) in the first charge of the battery pack must be minimized.

[0071] Therefore, it is generally believed that the maximum amount of Li that can be reversibly sandwiched between graphene planes in perfect graphene crystals appears in graphene intercalation compounds represented by LixC6 (x=1), corresponding to a theoretical 372 mAh / g. However, such limited specific capacity cannot adequately meet the demanding requirements of the high energy density power needed by modern electronic devices and EVs. Therefore, carbon-based anodes, such as those with Li intercalation in graphite, can exhibit extended cycle life due to the presence of a surface-electrolyte interface (SEI), which is generated during the initial charge-discharge cycles by reactions between Li and the surrounding electrolyte or between Li and the surface / edge atoms or functional groups of the anode. This refers to the fact that some of the Li ions consumed in this reaction during SEI formation may be derived from the Li ions originally intended for charge transfer, which refers to the dissociation of elemental Li in carbon-based structures, such as those with carbon intercalation within the anode.

[0072] As is typical of Li-ion battery packs, charge transfer can occur during the movement of Li ions in the electrolyte across the porous spacer to the cathode, related to electron release and transport to facilitate current conduction for powering the load. During repeated charge-discharge cycles of a Li-ion battery pack, an SEI (Sediment Ion Layer) forms, and some of the Li ions migrating through the electrolyte become part of the inert SEI layer and are described as becoming "irreversible" because they are no longer active elements or ions for charge transfer. Therefore, it is necessary to minimize the amount of Li used to form an effective SEI layer. In addition to SEI formation, Qir has also been attributed to graphite exfoliation caused by electrolyte / solvent intercalation and other side reactions.

[0073] Next, amorphous carbon contains little or no micron or nanocrystals and can include both "soft carbon" and "hard carbon". Soft carbon refers to carbon materials that can be graphitized at temperatures of about 2,500°C or higher. In contrast, hard carbon refers to carbon materials that cannot be graphitized at temperatures above 2,500°C.

[0074] In practice and industry, the so-called "amorphous carbon" commonly used as an anode active material is not purely amorphous, but actually contains a trace amount of micron or nanometer-sized crystallites. Each crystallite is defined as a few graphene sheets oriented to be stacked and bonded together by weak van der Waals forces. The number of graphene sheets can vary from one to several hundred, resulting in c-direction dimensions such as a thickness Le typically ranging from 0.34 nm to 100 nm. The length or width (La) of these crystallites is typically between tens of nanometers and micrometers. Among such carbon materials, soft carbon and hard carbon can be produced by low-temperature pyrolysis (550-1,000℃) and exhibit reversible specific capacities of 400-800 mAh / g in the 0-2.5 V range. So-called "cardboard box" carbon materials with enhanced specific capacities approaching 700 mAh / g have been produced.

[0075] The research team has achieved enhanced specific capacities of up to 700 mAh / g by milling graphite, coke, or carbon fibers, and has explained the origin of the additional specific capacity under the assumption that Li ions are adsorbed on both sides of a single graphene sheet in disordered carbon containing some dispersed graphene sheets, known as "card house" materials. It has also been proposed that Li readily bonds to proton-passivated carbon, generating a series of edge-oriented Li-CH bonds. This could provide an additional source of Li+ in some disordered carbon. Other studies have shown the formation of Li metal monolayers on external graphene sheets with graphite nanocrystals. The amorphous carbon discussed is prepared by pyrolysis of epoxy resin and can be called polymer carbon. Anode materials based on polymer carbon have also been investigated.

[0076] Chemical properties, performance, cost, and safety characteristics can vary in Li-ion battery pack variants. Handheld electronic devices can utilize Li polymer battery packs, which use a polymer gel as the electrolyte and Li cobalt oxide (LiCoO2) as the cathode material. This configuration offers relatively high energy density but may present safety risks, especially in the event of damage. Li iron phosphate (LiFePO4), Li-ion manganese oxide battery packs (LiMn2O4, Li2MnO3, or LMO), and Li nickel manganese cobalt oxide (LiNiMnCoO2 or NMC) all offer lower energy densities but provide longer lifespans and a lower likelihood of fire or explosion. Therefore, these battery packs are widely used in power tools, medical equipment, and other applications. Specifically, NMC is often considered for automotive applications. [ Lithium (Li) ] [ sulfur ] [ (S)] [ battery pack ] [ ]

[0077] Lithium-sulfur battery packs, referred to as Li-S battery packs in this paper, are a type of rechargeable battery pack known for their high specific energy. The relatively low atomic weight of Li and the medium atomic weight of S result in Li-S battery packs being relatively lightweight at approximately the density of water.

[0078] Li-S battery packs can replace lithium-ion batteries due to their higher energy density and reduced cost resulting from the use of sulfur. Li-S battery packs can provide a specific energy of approximately 500 Wh / kg, which is significantly better than many conventional Li-ion battery packs that typically range from 150 to 250 Wh / kg. Li-S battery packs with up to 1,500 charge-discharge cycles have been demonstrated. Despite these advantages, a key challenge for Li-S battery packs is the polysulfide "shuttle" effect, which causes the active material to gradually leak from the cathode, resulting in a short overall battery life. Furthermore, the extremely low conductivity of the sulfur cathode requires an additional mass of conductive reagent to utilize the effective mass contribution to the overall capacity. The large-volume expansion of the sulfur cathode from elemental sulfur (S) to Li₂S and the large amount of electrolyte required are also areas of concern.

[0079] The chemical processes in a Li-S battery include the dissolution of Li from the anode surface during discharge and its incorporation into the alkali metal polysulfide salt, as well as the reverse deposition of lithium onto the anode during charging. At the anode surface, metallic lithium dissolution occurs, and electrons and lithium ions are generated during discharge and electrodeposition occurs during charging. The half-reaction is represented as: (Equation 1)

[0080] Similar to what has been observed in Li-ion battery packs, dissolution and / or electrodeposition reactions may lead to unstable growth of the solid-electrolyte interface (SEI) over time, generating effective sites for Li nucleation and dendritic growth. Dendritic growth causes internal short circuits in Li battery packs and ultimately leads to the failure of the battery pack itself.

[0081] In a Li-S battery pack, energy is stored in the sulfur electrode (S8), which serves as the cathode. During battery discharge cycles, Li ions in the electrolyte migrate from the anode to the cathode, where S is reduced to lithium sulfide (Li₂S). During the refill phase, sulfur is re-oxidized to S8. For illustrative purposes, the half-reactions are represented at a high level of abstraction as follows: (E ° ≈ 2.15 V vs. Li / Li+) (Equation 2)

[0082] In fact, the reduction reaction of S to Li2S is significantly more complex and involves the formation of several polysulfide Li (Li2Sx, 8 < x < 1) in a decreasing chain length according to the following sequence: (Equation 3)

[0083] The final product is a mixture of Li₂S₂ and Li₂S, rather than pure Li₂S, due to the slow reduction kinetics of Li₂S. This contrasts with conventional Li-ion batteries where Li ions are sandwiched between the anode and cathode. For example, in a Li₂S battery system, each S atom can accommodate two Li ions. Typically, Li-ion battery packs can only hold 0.5-0.7 lithium ions per host atom. Therefore, Li-S allows for a much higher Li storage density. When the battery discharges, the polysulfide (PS) is sequentially reduced on the cathode surface: S8 → Li2S8 → Li2S6 → Li2S4 → Li2S3 (Equation 4)

[0084] On the porous diffusion spacer, the S polymer forms a cell charge at the cathode: Li₂S → Li₂S₂ → Li₂S₃ → Li₂S₄ → Li₂S₆ → Li₂S₈ → S₈ (Equation 5) These reactions are similar to those in sodium (Na)-S battery packs.

[0085] The main challenges for Li-S battery systems include the relatively low conductivity of sulfur, its large volume change during discharge, and finding a suitable cathode, such as one constructed from any of the carbon-based structures disclosed in this invention, which is the first step towards the commercialization of Li-S battery packs. Currently, conventional Li-S battery packs use carbon / sulfur cathodes and Li anodes. Sulfur is naturally abundant and relatively inexpensive, but it does not actually possess the conductivity of 5 × 10⁻³⁰ S‧cm⁻¹ at 25°C. Carbon coatings provide the missing conductivity. Carbon nanofibers offer an efficient electron conduction path and structural integrity while incurring the disadvantage of higher cost.

[0086] One problem with Li-S design is that when S in the cathode absorbs Li, a volume expansion of the LixS composition occurs, and the predicted volume expansion of Li2S is almost 80% of the original S volume. This results in large mechanical stress on the cathode, which is a major cause of rapid degradation. This process reduces the contact between carbon (C) and S and prevents Li ions from flowing to the carbon surface.

[0087] The mechanical properties of lithium-ionized S compounds are largely dependent on the Li content, and the strength of lithium-ionized S compounds increases with increasing Li content, but this increase is not linear with Li content. One of the major shortcomings of most Li-S batteries is related to incompatible reactions with the electrolyte. When S and Li₂S are relatively insoluble in most electrolytes, many intermediate polysulfides (PS) are not suitable for dissolving Li₂Sn into the electrolyte, which may lead to the irreversible loss of available S. The use of highly reactive Li as a negative electrode causes dissociation in most other commonly used electrolyte types. The use of protective layers on the anode surface has been studied to improve battery safety; for example, the use of Teflon coatings has shown improved electrolyte stability, and LIPON and Li₃N have also shown promising performance.

[0088] The "shuttle" effect has been observed to be a major cause of degradation in Li-S battery packs. LiPS (Li2Sx, 6 ≤ x ≤ 8) is highly soluble in the electrolyte commonly used in Li-S battery packs. It forms and leaks from the cathode, diffuses to the anode, where it is reduced to short-chain PS, and diffuses back to the cathode, where long-chain PS reforms. This process leads to continuous leakage of active material from the cathode, lithium corrosion, low coulombic efficiency, and short battery life due to battery self-discharge. Furthermore, the "shuttle" effect contributes to the characteristic self-discharge of Li-S battery packs, which is attributed to the slow dissolution of PS, also occurring in a static state. The "shuttle" effect in Li-S battery packs can be quantified by a factor fc (0 < fc < 1), which is assessed by the extension of the flat region of the charging voltage. The factor fc is given by the following expression: (Equation 6) Where ks, qup, [Stot], and Ic are the kinetic constant, the specific capacity contributing to the anode flat region, the total sulfur concentration, and the charging current, respectively. [ Electrical conductivity of carbon-based materials ] [ ]

[0089] Advances in highly conductive carbon materials such as carbon nanotubes (CNTs), graphene, amorphous carbon, and / or crystalline graphite in electronic devices allow for the printing of these materials onto many types of surfaces without the need for printed circuit boards and without the use of materials or compounds identified as toxic to humans. The use of highly conductive carbon as a raw material or other material during any one or more of the layering fabrication methods described above facilitates the manufacture of battery packs with microlattice structures suitable for enhanced functionality, power storage and transmission, and optimal efficiency. While many of the described devices can serve as power sources such as battery packs or capacitors, those skilled in the art will understand that printing techniques such as 3D printing can use highly conductive carbon materials such as carbon nanotubes (CNTs), graphene, amorphous carbon, or crystalline graphite to form other electronic devices for assembly.

[0090] Printing techniques using highly conductive carbon materials such as carbon nanotubes (CNTs), graphene, amorphous carbon, or crystalline graphite can be implemented in the manufacture of and / or otherwise incorporated into devices such as antennas, tuned antennas, sensors, biosensors, energy harvesters, photovoltaic cells, and other electronic devices. [ graphene ] [ ]

[0091] Graphene is an allotrope of carbon that exists as an atomic monolayer within a two-dimensional hexagonal lattice where one atom forms each vertex. It is the fundamental structural element for other allotropes, including graphite, charcoal, carbon nanotubes, and fullerenes. It can also be considered an infinitely large aromatic molecule, that is, the ultimate case of the polycyclic aromatic hydrocarbon family.

[0092] Graphene possesses a unique set of properties that distinguish it from other elements. Proportionate to its thickness, it is approximately 100 times stronger than the strongest steel. Yet, its density is significantly lower than any other steel, with surface-dependent mass, such as surface-related mass, at 0.763 mg / m². It conducts heat and electricity extremely efficiently and is nearly transparent. Graphene also exhibits even greater and nonlinear diamagnetic properties than graphite and can be levitated by Nd-Fe-B magnets. Researchers have identified bipolar transistor effects, charge shock transport, and large quantum oscillations within the material. Its end-use applications are broad, finding unique implementations in advanced materials and composites, and as a forming material to construct decorative supports for use in Li-ion battery electrode construction to enhance ion transport and current conduction, resulting in specific capacity and power delivery profiles unattainable in other conventional battery technologies. [ Chemical functionalization of graphene ]

[0093] Functionalization refers to the process of adding new functions, characteristics, capabilities, or properties to a material by altering the chemical substances on its surface. Functionalization is used throughout chemical reactions, materials science, bioengineering, textile engineering, and nanotechnology. It can be performed by attaching molecules or nanoparticles to the material surface via chemical bonds or adsorption, or by adsorbing atoms, ions, or molecules from gases, liquids, or dissolved solids onto the surface to create an adsorbent film without forming covalent or ionic bonds.

[0094] The functionalization and dispersion of graphene sheets are of critical importance to their respective end-use applications. The chemical functionalization of graphene enables the material to be processed by solvent-assisted techniques such as layer-by-layer assembly, spin coating, and filtration, while also preventing the agglomeration of monolayer graphene (SLG) during reduction and maintaining the inherent properties of graphene.

[0095] Currently, graphene functionalization can be achieved through both covalent and non-covalent modification techniques. In both cases, surface modification of graphene oxide is performed, followed by reduction to obtain functionalized graphene. It has been found that both covalent and non-covalent modification techniques are highly effective in preparing processable graphene.

[0096] However, the electrical conductivity of functionalized graphene has been observed to be significantly lower than that of pure graphene. Furthermore, the surface area of ​​functionalized graphene prepared by covalent and non-covalent techniques is significantly reduced due to the destructive chemical oxidation of sheet graphite, followed by acoustic treatment, functionalization, and chemical reduction. To overcome these problems, studies have reported the preparation of functionalized graphene directly from graphite in a one-step process. In all these cases, surface modification of graphene prevents agglomeration and promotes the formation of stable dispersions. Surface-modified graphene can be used to manufacture polymer nanocomposites, Li-ion battery electrodes, supercapacitor devices, drug delivery systems, solar cells, memory devices, transistor devices, biosensors, etc. [ graphite ]

[0097] As is commonly understood and as mentioned in this article, graphite refers to the crystalline form of carbon, an element with atoms arranged in a hexagonal structure. Graphite exists naturally in this form and is the most stable form of carbon under standard conditions, such as atmospheric conditions. Furthermore, under high pressure and high temperature, graphite transforms into diamond. Graphite is used in pencils and lubricants. Its high conductivity makes it suitable for use in electronic products such as electrodes, battery packs, and solar panels. [ roll to roll ] [ (R2R) ] [ deal with ]

[0098] R2R processing refers to a method of producing electronic devices on a roll of flexible plastic or metal foil. R2R processing can also refer to coating, printing, or performing other processes starting with a roll of flexible material, and then rewinding it to produce an output roll. These methods, and other methods such as sheeting, can be grouped together under the general term "conversion". Once the material roll has been coated, laminated, or printed, it can subsequently be cut and / or slit into its finished size on a slitting and rewinding machine.

[0099] The R2R process for large-area electronic devices can reduce manufacturing costs. Other applications can emerge by utilizing the flexible properties of substrates for large-area flexible displays, such as embedded electronic devices, 3D-printed Li-ion battery packs, large-area flexible displays, and roll-up portable displays. [ Redox ] [ (Oxidation-Reduction / Redox) ] [ reaction ]

[0100] Redox reactions are a type of chemical reaction in which the oxidation state of atoms is changed. Redox reactions are characterized by the transfer of electrons between chemical species, most commonly involving a reducing agent undergoing oxidation by losing electrons, while an oxidizing agent undergoes reduction by gaining electrons. It is claimed that the chemical species that has lost electrons has been oxidized, while the chemical species that has gained electrons has been reduced. [ Interspersed ]

[0101] Intercalation refers to the reversible inclusion or insertion of molecules or ions into materials with a layered structure. Examples are found in graphite, graphene, and transition metal dichalcogenides. [ Li ] [ Intercalated into two or more layers of graphene ]

[0102] The current challenges in the field of Li-ion battery packs, particularly regarding the electrical storage capacity of graphene and Li storage methods within graphite, necessitate further development. Therefore, efforts have been made to: further develop three-dimensional bilayer graphene foams with fewer defects and predominantly Bernal stacking, i.e., a type of bilayer graphene in which half of the atoms are directly located within the hexagonal center of the lower graphene sheet and the other half are located within a single atom; and to investigate their Li storage capacity, methods, kinetics, and resistance. Li atoms can be stored solely within the graphene interlayer. Furthermore, various physiological and chemical characterizations of segmented Li bilayer graphene products have further revealed regular Li interlayering and illustrated Li storage modes for these two sizes. [ Electrochemical capacitors ] [ (EC) ]

[0103] Electrolytic capacitors (ECs), also known as ultracapacitors or supercapacitors, are considered for use in hybrid or full EVs. ECs can supplement or, in specific applications, replace conventional battery packs in EVs to provide brief bursts of power (such as the sudden throttle increases often required for forward propulsion and rapid acceleration), including high-efficiency Li-ion battery packs. While conventional battery packs can still provide uniform power for steady driving at normal highway speeds, ultracapacitors, with their ability to release energy much faster than battery packs, can activate at specific times, such as when such an equipped vehicle needs acceleration, to supplement the power provided by the battery pack for purposes such as merging, passing, emergency maneuvering, and hill climbing.

[0104] ECs must also store enough energy to provide an acceptable driving range of 220-325 miles or longer. Furthermore, to be cost- and weight-efficient relative to the additional battery pack capacity, ECs must combine sufficient specific energy and specific power with long cycle life while also meeting cost targets. Specifically, ECs used in EV applications must store approximately 400 Wh of energy, be able to deliver approximately 40 kW of power for about 10 seconds, and provide a long cycle life such as >100,000 cycles.

[0105] Electrolyte capacitors (ECs) with volumetric capacitance densities 10 to 100 times greater than conventional capacitors are derived from the use of graphene-based materials with scaffolds, characterized by graphene and / or porous electrodes constructed from it to generate large effective "plate areas" and from energy storage within diffused bilayers. This bilayer, naturally occurring at the solid-electrolyte interface when a voltage is applied, is only about 1-2 nm thick, thus forming extremely small effective "plate separation." In some ECs, the stored energy is further expanded by a pseudocapacitive effect that occurs again at the solid-electrolyte interface due to electrochemical phenomena such as redox charge transfer. Bilayer capacitors are based on high-surface-area electrode materials such as activated carbon immersed in the electrolyte. Polarized bilayers are formed at the electrode-electrolyte interface, providing high capacitance. [Overview] [ - ] [ Foreword ]

[0106] Technological advancements in modern carbon-based materials such as graphene have enhanced their applications in numerous end-use areas, including advanced secondary battery packs. These packs can utilize the advantageous properties of carbon materials and carbon-based materials by employing electrochemically sandwiched or de-sanded Li, properties that can be significantly influenced by their respective morphology, crystallinity, microcrystal orientation, and defects. For example, the electrical storage capacity of Li-ion battery packs can be enhanced by selecting and integrating desired nanostructured carbon materials, such as graphite and graphene or nanoscale graphite, nanofibers, separated single-walled carbon nanotubes, nanospheres, and specific allotropes of nanoscale amorphous carbon, each possessing a small carbon nanostructure of no more than about 2 µm.

[0107] Known methods for manufacturing carbon and Li-ion electrodes for rechargeable Li batteries include steps for forming a carbon electrode. Such a carbon electrode can be constructed from graphite carbon particles bonded together by an ethylene propylene diene monomer binder to achieve a carbon electrode capable of subsequently intercalating Li ions. Subsequently, the carbon electrode is reacted with lithium (Li) metal to incorporate the Li ions obtained therefrom into the graphite carbon particles of the electrode. A voltage can be repeatedly applied to the carbon electrode to initially induce a surface reaction between Li ions, and is repeatedly applied to the carbon, subsequently inducing Li ions to intercalate into the crystalline layer of the graphite carbon particles. With repeated voltage application, intercalation can be achieved to approach the theoretical maximum value as needed and to aid current conduction.

[0108] Other exfoliated graphite-based composite materials are related to the following: ● Capable of absorbing and desorbing alkali metals or alkali metal ions, specifically micron or nano-sized particles or coatings containing Li ions; and ● A peeled graphite sheet that is substantially interconnected to form a porous conductive graphite network including pores defined therein. The particles or coating reside in the pores of the mesh or are attached to the mesh sheets. The amount of exfoliated graphite is between 5% and 90% by weight, and the number of particles or the amount of coating is between 95% and 10% by weight.

[0109] Furthermore, the combination of high-capacity silicon-based anode active materials with high-capacity Li-rich cathode active materials has proven effective. For some silicon-based active materials, Li supplementation has shown improved cycle performance and reduced irreversible capacity loss. Silicon-based active materials can be formed in composite materials with conductive coatings such as pyrolytic carbon coatings or metallic coatings, and the composite materials can also contain other conductive carbon components such as carbon nanofibers and carbon nanoparticles.

[0110] Furthermore, known rechargeable battery packs containing alkali metals and organic electrolytes experience minimal capacity loss when alkali metals are sandwiched between carbon-containing electrodes. The carbon-containing electrodes may comprise a multiphase composition including highly graphitized and less graphitized phases, or a single-phase highly graphitized composition subjected to Li sandwiching at temperatures above about 50°C. During repeated cycling, the presence of conductive filaments, such as carbon black, tightly dispersed with the carbon-containing composition further minimizes capacity loss.

[0111] Furthermore, known Li-based anode materials are characterized by including a specific surface area of ​​1 m² / g or greater for carbon-containing anode active material, a styrene-butadiene rubber binder, and fiber diameter molded into 1,000 nanometer carbon fibers. These anode materials are used in Li-ion battery packs, which possess desirable characteristics such as low electrode resistance, high electrode strength, electrolytes with excellent permeability, high energy density, and high-speed charging / discharging. The negative electrode material contains 0.05% to 20% by mass of carbon fibers and 0.1% to 6.0% by mass of styrene. Butadiene rubber forms the binder and may further contain 0.3% to 3% by mass of a thickener such as carboxymethyl methyl cellulose.

[0112] Existing technologies have been shown to be relevant to battery packs with the following anode active materials: ● Pre-lithiation; and ● Pre-crushing. Such anodes can be prepared using methods including: ● Provides anode active materials; ● The required amount of Li is sandwiched or absorbed into the anode active material to produce a pre-lithiated anode active material; ● The pre-lithiated anode active material is ground into fine particles with an average size of less than 10 µm, preferably < 1 µm, and most preferably < 200 nm. This grinding refers to reducing the average particle size of solid material from one particle size to a smaller average particle size by crushing, grinding, cutting, vibration, or other methods. ● Combining multiple fine particles of pre-lithiated anode active material with conductive additives and / or binder materials to form an anode. The pre-lithiated particles are protected by a Li ion-conducting matrix or coating material. The matrix material is reinforced with nano-graphene sheets.

[0113] Graphite nanofibers have also been revealed, including tubular fullerenes (commonly known as "bucky tubes"), nanotubes, and fibrils used as electrodes in electrochemical capacitors through chemical substitution functionalization. Electrodes based on graphite nanofibers enhance the performance of electrochemical capacitors. Preferred nanofibers have a surface area greater than approximately 200 m² / gm and are substantially free of micropores.

[0114] It is known that high surface area carbon nanofibers have an outer surface on which a porous high surface area layer is formed. A method for manufacturing high surface area carbon nanofibers includes pyrolyzing a polymer coating material disposed on the outer surface of the carbon nanofibers at a temperature below the melting temperature of the polymer coating material. Polymer coating materials used for high surface area carbon nanofibers may include phenolic resins such as formaldehyde, polyacrylonitrile, styrene, divinylbenzene, cellulose polymers, and cyclotriethynylbenzene. The high surface area polymer covering the carbon nanofibers may be functionalized with one or more functional groups. [ Synthesize the carbon disclosed in this invention ]

[0115] As presented above, conventional carbon-based compositions or compounds containing Li may include conventional battery electrode materials such as graphene or multilayer 3D graphene particles; conductive carbon particles; and binders such as binders provided in fluid form such as liquids and / or in particulate form, which are formulated to retain the carbon-based particles in their respective desired locations and to provide overall structural integrity for the carbon-based system.

[0116] In conventional techniques, particles are typically deposited entirely, such as by dropping onto existing current collectors containing slurry-cast electrodes made of metal foil, such as copper. The slurry is typically prepared to contain an organic binder or adhesive material called NMP, used as a solvent in the petrochemical and plastics industries, and an organic compound composed of five lactamines, utilizing its non-volatile nature and ability to dissolve a variety of materials. The ratio of active material to conductive carbon or carbon-based particles is typically 5 parts conductive carbon: the majority of which also includes a nominal amount of binder or adhesive material (such as NMP) of active material. The relative amounts of binder and carbon conductive phase can be specified by creating one or more conductive pathways between the larger particles of the active material mentioned.

[0117] Regarding the difficulties associated with the implementation and use of binders in secondary battery packs, research has shown that developing high-efficiency battery pack systems requires optimizing each battery pack component, from the electrodes and electrolyte to the binder system. However, conventional strategies for manufacturing battery pack electrodes by casting a mixture of active materials, non-conductive polymer binders, and conductive additives onto metal foil current collectors often result in electronic or ionic bottlenecks and poor contact due to the random distribution of the conductive phase. These bottlenecks and poor contact can be problems that may be observed in the anode or cathode. Furthermore, when high-capacity electrode materials are used, the high stress generated during the electrochemical reaction can compromise the mechanical integrity of conventional binder systems, leading to a shortened cycle life of the battery pack. Therefore, there is a critical need for novel and robust binder systems or scaffolded carbon-based electrode structures that exhibit structural integrity without the use of binders, providing reliable, low-resistance, and continuous internal voids, micropores, and pathways to retain active materials and connect all areas of the electrode when needed during the charge-discharge cycle of the battery pack.

[0118] In contrast to conventional approaches and the shortcomings of adhesive performance associated with shortened battery cycle life, the inventive composition and method / process disclosed in this invention eliminate: any and all forms of the adhesive phase; and potential specific regions, characteristics, and / or states of the conductive phase defined by larger carbon-based particles, such as graphene and / or graphene extracted from graphite or otherwise produced.

[0119] This is achieved by fabricating particles in which interconnected 3D polymers of multilayer graphene sheets are fused or sintered together, such as randomly or with controlled orientation (e.g., orthogonally), or otherwise joined together, to act as a type of internally self-supporting "binder" or as a bonding material that acts as a binder replacement, effectively allowing the elimination of separate traditional binder materials to achieve substantial weight reduction. This format also allows for the elimination of separate and dedicated current collectors, typically required components in many battery packs. The elimination of the binder phase and / or current collector provides beneficial and desirable features, such as: ● It has a low unit production cost that allows for quality manufacturability. ● High reversible specific capacity, ● Low irreversible capacity, ● Small granularity, such as small granularity that allows for high throughput / rate capacity. ● For ease of integration and compatibility with common electrolytes in commercial battery pack applications, and ● Long charge-discharge cycle life for consumer benefits across any number of demanding end-use applications, including automotive, aircraft, and spacecraft.

[0120] Notably, the techniques disclosed herein produce unexpectedly advantageous results. They do not require conventional methods such as graphene exfoliation to produce graphene sheets, but instead synthesize one or more multi-peaked carbon-based s from a vapor stream primarily composed of atmospheric plasma. The synthesis of carbon-based particles can occur operationally via nucleation from initially formed homogeneous carbon-based nuclei or during direct deposition onto a support or sacrificial substrate. Therefore, any one or more permissible growth methods disclosed in this invention do not rely on conventionally required seed particles to decorate carbon-based structures, on which nucleation occurs.

[0121] In the prior art, the production of functionalized graphene relies on the use of graphite as a starting material. Graphite, as a conductive material, has been used as an electrode in battery packs and other electrochemical devices. In addition to its function as an inert electrode, electrochemical methods have been employed to form graphite intercalation compounds (GICs), and more recently, graphite has been exfoliated into few-layered graphene. As is generally understood and as mentioned herein, exfoliation means—in cases involving intercalation chemicals—the complete separation of material layers and typically requires aggressive conditions involving highly polar solvents and aggressive reagents. Electrochemical methods are attractive because they eliminate the use of chemical oxidants as the driving force for intercalation or exfoliation, and the electrodynamics for tunable GICs are controllable. More importantly, the extensive capabilities of electrochemical functionalization and modification enable the easy synthesis of functionalized graphenes and their value-added nanocomposites.

[0122] Unlike exfoliation, which includes thermal exfoliation of graphite for the production of graphene, the method disclosed in this invention relates to one or more gaseous species comprising carbon, such as methane (CH4), flowing into the reaction chamber of a microwave-dominated or thermal reactor. Upon receiving energy, such as energy provided by electromagnetic radiation and / or thermal energy, the gaseous species spontaneously decomposes to form allotropes with other decomposed carbon from additional gaseous species supplied to the reactor, thereby generating initial carbon-dominated sites, such as the formed particles, which have or otherwise promote the following: ● Additional particles grow or nucleate based on defects in the initially formed particles; or ● Orthogonal fusion or sintering of additional carbon-based particles, where there is sufficient local energy at the collision point of the colliding particles to combine them. [System Architecture] [ Carbon-based particles ] [ - ] [ Detailed Explanation ] [ ]

[0123] Figure 1A shows carbon-based particles 100A with controllable electro- and ionic conduction gradients therein, within which various states of the subject matter disclosed herein can be implemented. The carbon-based particles 100A can be synthesized via binder-free self-assembly, characterized by multi-peak sizes, including various pores, channels, voids, pathways, channels, or the like, any one or more of which are defined to have specific dimensions, such as mesopores. According to IUPAC nomenclature, mesoporous materials refer to materials containing pores with diameters between 2 nm and 50 nm. For comparative purposes, IUPAC defines microporous materials as materials with pores having diameters less than 2 nm and macroporous materials as materials with pores having diameters greater than 50 nm.

[0124] Mesoporous materials can include various types of silicon dioxide and alumina with mesopores of similar sizes. Mesoporous oxides of niobium, tantalum, titanium, zirconium, cerium, and tin have been studied and reported. All variations of mesoporous materials and mesoporous carbon (such as carbon and carbon-based materials) with pores, flow paths, channels, or similar features of at least one mesopore size have achieved specific bulges and are directly applied in energy storage devices. Mesoporous carbon can be defined as having porosity in the mesoporous range, which significantly increases the specific surface area. Another commonly used mesoporous material is activated carbon, which refers to carbon processed to have small, low-volume pores with increased surface area. In the mesoporous case, activated carbon is typically composed of carbon structures with mesoporous and microporous porosities, depending on its synthesis conditions. According to IUPAC, mesoporous materials can be disordered or ordered in their mesolayer structure. In crystalline inorganic materials, the mesoporous structure significantly restricts the number of lattice units, which significantly alters the solid-state chemical composition. For example, the battery pack performance of mesoporous electroactive materials is significantly different from that of batteries with bulk structures.

[0125] As seen in the prior art, carbon-based particles 100A nucleate and grow in a vapor stream primarily composed of atmospheric plasma, such as methane (CH4), to form initial carbon-containing and / or carbon-based particles, requiring, indiscriminately or explicitly, independent individual seed particles, around which carbon structures subsequently grow. According to embodiments disclosed in this invention, initial carbon-based synthetic particles, independent of independent seed particles, can then be amplified: [●] Describes the systematic aggregation of nucleation and / or growth within a microwave plasma reaction chamber, based on initial carbon-based homogeneous nucleation independent of seed particles derived from additional carbon-based materials entering the carbon-containing gas atmosphere; or [●] This amplification is carried out by growth and / or direct deposition onto a support or sacrificial substrate, such as a current collector, within a thermal reactor. Agglomeration refers to the method by which two phase regions of the same composition come together to form a larger phase region. In other words, it is the method by which two or more separate masses of miscible substances appear to be pulled together by minimal contact. Carbon-based particles 100A may alternatively be referred to simply as particles and / or any other similar term. As is generally understood and used herein, according to the nomenclature of the International Union of Pure and Applied Chemistry (IUPAC), pores in the term can be defined as materials containing pores with diameters between 2 nm and 50 nm.

[0126] The synthesis and / or growth of carbon-based particles 100A in microwave-based reactors (such as microwave reactors) and / or reaction chambers otherwise combined with them is disclosed in U.S. Patent No. 9,767,992, filed September 19, 2017, by Stowell et al., "Microwave Chemical Processing Reactor," which is incorporated herein by reference in its entirety. Synthesis can occur in systems other than microwave reactors, such as in thermal reactors, which generally refer to chemical reactors defined by enclosed volumes in which temperature-dependent chemical reactors are present.

[0127] Carbon-based particles 100A, also shown as carbon-based particles 100D in Figure 1D, are synthesized as described herein, forming a three-dimensional (3D) hierarchical structure that combines short-range localized nanostructures with long-range approximate fractal features. In this case, it refers to the formation of successive layers orthogonally positioned to each other. Orthogonality here is defined as involving a 90-degree rotation of each successive layer relative to the layer below it, and so on, allowing the creation of vertical or substantially vertical layers and / or intermediate layers.

[0128] An interconnected microstructure 107E suitable for use within the cathode of an electrochemical battery for a lithium-sulfur (Li₂S) secondary system is shown in FIG1E, which itself shows an enlarged and more detailed view of the hierarchical pores 101A shown in FIG1A and 1D. In some embodiments, as shown in FIG1A, the outline and shape of the interconnected microstructure 107E may structurally define an open porous support 102A and diffusion paths 109E, which are suitable for Li ion transport from the anode to the cathode during discharge-charge cycles. The interconnected microstructure 107E may include: [●] Provides tunable Li ion channels with microporous frameworks defined by a size > 50 nm 101E, such as diffusion paths 109E; [●] A mesoporous channel, defined by a size of approximately 10²E (generally defined according to IUPAC nomenclature and referred to as a mesoporous channel or mesoporous channel) of approximately 20 nm to approximately 50 nm, serving as a high-speed Li-ion channel for rapid Li-ion transport; and [●] Microporous textures defined by a size of < 4 nm 103E, such as pores 105E, for charge storage and / or confinement of active materials (such as sulfur (S) in the LiS system).

[0129] In addition to providing pores 105E for confining active materials and defining ion transport pathways, a hierarchical porous network 100E, including diffusion pathways 109E, can be assembled to define interconnected microstructures 107E for providing active Li interlayer structures. Therefore, the hierarchical porous network 100E having carbon-dominant particles 100D can be implemented in anodes or cathodes, or in Li-ion or LiS battery systems, for example, with a specific capacity rating between about 744 mAh / g and about 1,116 mAh / g. For Li-ion or LiS configurations, such as when supplied by molten Li metal via capillary infusion, Li can wet the open porous scaffold to at least partially chemically react with the exposed carbon therein in the reaction system.

[0130] One or more physical, electrical, chemical, and / or material properties of the carbon-based particles 100A can be defined during their synthesis. Furthermore, dopants (such as Si, SiO, SiO2, Ti, TiO, Sn, Zn, and / or their analogues) intended to be introduced into the chemical material to alter its original electrical or optical properties can dynamically influence, at least partially, material properties including conductivity, wettability, and / or ion conduction or transport via the hierarchical porous network 100E during the synthesis of the carbon-based particles 100A. More generally, microporous textures having a size of 103E and / or hierarchical porous network 100E can be synthesized, prepared, or generated to include smaller pores confined to micrometers for chemicals such as sulfur (S), defined as being in the range of 1 nm to 3 nm. Additionally, the diameter (La) of each graphene sheet, such as those shown in Figure 1C, can be in the range of 50 nm to 200 nm.

[0131] The open porous scaffold 102A can be synthesized onto metal foil current collectors in end-use battery pack applications without relying on binders such as conventional non-conductive polymer binders typically used in conjunction with conductive additives. Conventional formulations involving binder use can lead to electron / current conduction issues or ion shrinkage and poor contact due to the randomly distributed conductive phase. Furthermore, when high-capacity electrode materials are used, the relatively high physical stress generated during the electrochemical reaction can compromise the mechanical integrity of conventional binder systems, thus subsequently shortening the battery pack's cycle life.

[0132] A vapor stream for synthesizing carbon-based particles 100A, or carbon-based particles 100A or carbon-based particles 100D consistent with them, can at least partially flow to a plasma, such as generating and / or flowing to a region adjacent to the plasma in a reactor and / or chemical reaction vessel. Such plasma reactors can be configured to deliver microwave energy toward the vapor stream to at least partially assist the synthesis of carbon-based particles 100A, and can involve nucleation and growth of carbon-based and / or carbon-derived particles from carbon-based gaseous species (such as methane (CH4)), wherein such nucleation and growth can substantially occur within the reactor from initially formed carbon-based homogeneous nucleation independent of seed particles. Such reactors contain a gas-solid reaction control under non-equilibrium conditions, wherein the gas-solid reaction may be at least partially controlled by one or more of the following: the free potential and / or thermal energy associated with the synthesis of carbon-based gaseous species of carbon-based particles introduced into the reactor; and / or the kinetic momentum associated with the gas-solid reaction.

[0133] The vapor stream can flow into the reactor and / or reaction chamber at substantially atmospheric pressure to synthesize carbon-based particles 100A. Furthermore, changes in the wettability of the carbon-based particles 100A and / or any constituent member such as the open porous support 102A can at least partially involve the polarity adjustment of the carbon matrix associated with the carbon-based particles 100A. [Synthesis Program] [ microwave reactor ] [ ]

[0134] A vapor stream of a carbonaceous constituent species, such as methane (CH4), can flow into one of two general types of reactors to produce carbon-based particles 100A: a thermal reactor; or a microwave-based reactor. A suitable type of microwave reactor is disclosed in U.S. Patent No. 9,767,992, filed September 19, 2017, by Stowell et al., "Microwave Chemical Processing Reactor," which is incorporated herein by reference in its entirety.

[0135] The term "in operation" refers to a novel chemical synthesis method based on contacting particulate material derived from carbonaceous gaseous species such as methane (CH4) to pyrolyze them. As generally understood and as mentioned herein, pyrolysis refers to a methane pyrolysis technique for producing elemental carbon and hydrogen, such as high-quality carbon black, without intractable carbon monoxide pollution and with virtually no carbon dioxide emissions. The basic endothermic reaction that can occur in a microwave reactor to produce carbon-based particles 100A is shown in the following equation (7): CH4 + 74.85 kJ / mol → C+ 2H2 (7)

[0136] Carbon derived from the pyrolysis methods described above and / or similar or dissimilar methods can be fused together and simultaneously dispersed in the gas phase, a process known as "in operation," to produce carbon-dominant particles, structures, substantially 2D graphene sheets, 3D aggregates, and / or pathways defined therein, including: ● Figure 1C schematically depicts the interconnection of multiple layers of graphene sheets 101C, forming an open porous support 102A that facilitates conductivity along and across the contact points of the graphene sheets 101C shown in Figure 1B. The 3D aggregate 101B and / or monolayer graphene may include and / or refer to 5 to 15 layers of few-layer graphene oriented in a stacked configuration to have a vertical height referred to as the stacking height (Lc); and ● One or more of the interconnected microstructures 107E that are dispersed together with or otherwise shaped by the interconnected 3D polymer 101B; in some configurations, the interconnected 3D polymer may be prepared to include one or more of monolayer graphene (SLG), few-layer graphene (FLG) defined as being in the range of 5 to 15 layers of graphene, or multilayer graphene (MLG).

[0137] As previously described, interconnected 3D polymers of multilayer graphene sheets, 101B, are orthogonally fused together to act as a type of internally self-supporting adhesive or bonding material, allowing the elimination of separate conventional adhesive materials. As is generally understood and mentioned herein, these procedures are substantially different from conventional sintering or calcination, which refers to methods of compressing and forming a solid mass of material by heat or pressure without melting it to the liquefaction point where the material bonds to each other at a specific acute angle.

[0138] In this paper, few-layer graphene (FLG) in the range of 5 to 15 layers is defined as fusing over time at an angle that is uneven relative to other FLG sheets to nucleate and / or grow at a certain angle and thus self-assemble. Furthermore, the processing conditions can be tuned to achieve carbon-based particle 100A, which also refers to the fully operational synthesis, nucleation, and / or growth of multiple carbon-based particles on the components and / or wall surfaces within the reaction chamber or in contact with other carbon-based materials.

[0139] The electrical conductivity of deposited carbon and / or carbon-based materials can be tuned by adding metal additives to the carbon phase in the first part of the deposition phase, or tuned to change the ratio of the various particles discussed. Other parameters and / or additives can be adjusted as part of a high-energy deposition method to make deposited carbon and / or carbon-based particles at a certain energy level either bond together or not bond together.

[0140] By enabling the on-the-fly nucleation and / or growth of carbon-based particles 100A in a vapor stream primarily composed of atmospheric plasma, or by directly nucleating and / or growing them onto a support or sacrificial substrate, numerous steps and components found in conventional battery packs and their manufacturing methods can be eliminated. Furthermore, significant adaptation and tunability can be enabled or otherwise added to the carbon and / or carbon-based materials discussed.

[0141] For example, conventional battery packs can use starting materials such as active materials and graphite, which can be obtained as readily available materials to be mixed into a slurry. In contrast, the carbon-based particles 100A disclosed herein can be used for real-time adaptation and / or tuning of material properties as part of a carbon or carbon-based material synthesis and / or deposition process, while such materials are being synthesized and / or deposited onto a substrate. This capability represents an unexpected, surprising, and substantially advantageous deviation from currently available capabilities in the production of carbon-based support electrode materials for secondary battery packs.

[0142] The reactor and / or reactor design disclosed in Stowell et al., "Microwave Chemical Processing Reactor," filed September 19, 2017, can be adjusted, configured, and / or adapted to control desired or undesirable nucleation sites on the inner surface of a reaction chamber exposed to carbon-based gaseous feedstock species such as methane (CH4). The quality of the operating particles can be influenced by their solubility in the gaseous species, in which they flow such that, once a specific energy level is reached, it is not inconceivable that carbon would decompose in the microwave reactor and form its own solid form, as described by thermal decomposition. [ Adjusting undesirable carbon buildup on the reaction chamber walls ] [ ]

[0143] Furthermore, the disclosed reactor and related systems can be tuned to proactively address problems associated with blockage in carbon-based microwave reactors, such as before observing undesirable processing conditions and passively after observing such conditions. For example, open surfaces, feed ports, hoses, conduits, and / or similar structures can accumulate undesirable carbon-based particulate matter as a byproduct of the performed synthesis process, producing carbon-based particles 100A. A central problem observed in microwave reactors may include this tendency to experience blockage in and / or along the flow orifices, related to walls and other surfaces exposed to gaseous carbonaceous species in a flow that also has carbon solubility. Therefore, undesirable growth on the reaction chamber walls and / or outlet pipes is possible. Over time, this growth extends outward and eventually impinges on the flow, potentially shutting down the chemical reactions occurring in the reactor and / or reaction chamber. Such phenomena can be similar to tubular structures, such as the exhaust gases and wall deposits from burning oil in high-efficiency or fast-running internal combustion engines. Instead of burning (such as combustion) fossil fuels like gasoline, methane is used to create unwanted carbon deposits on the pores of the reaction chamber, because the metal inside the reaction chamber itself has a carbon solubility level.

[0144] Although methane is primarily used to produce carbon-based particles 100A, any carbon-containing and / or hydrocarbon gas such as C2 or acetylene or C2H2, CH4, butane, natural gas, and biogas (such as biogas derived from the decomposition of biological matter) can also be used to provide a carbon source.

[0145] The uncontrollable and undesirable carbon growth within the exposed surface of the microwave reactor described can be compared to carbon growth occurring in the exhaust manifold of an internal combustion engine, such as one corresponding to the cylinder bore. This is particularly relevant in cases where the plasma plume, including the heat entering the plasma phase and the ignited gas, is located at the manifold initiation point, and the combusting gas and carbon-dominant fragments travel downwards and upwards through the manifold, cross-pipes, catalytic converter, and outlet pipe. Therefore, processing conditions can be actively tuned to regulate and thus accommodate potential carbon deposits in the microwave reactor, relying on the presence of plasma for hydrocarbon cracking. Maintaining this plasma requires a specific set of conditions; otherwise, backpressure buildup may disrupt the plasma before its generation and subsequent ignition. [ thermal reactor ] [ ]

[0146] In alternatives or additional schemes for the synthesis of carbon-based particles 100A in a microwave reactor, structured carbon can be produced by thermal cracking of hydrocarbons in a reactor such as a thermal reactor. An exemplary formulation may include the exposure of one or more of the aforementioned hydrocarbons to a heating element similar to a filament in a light bulb, where the carbon-based gaseous species are exposed.

[0147] Heating elements heat the interior of the reaction chamber where the carbon-containing gas is ionized. The carbon-containing gas, lacking sufficient oxygen to sustain combustion, does not ignite but instead becomes ionized through contact with incoming thermal radiation, such as in the form of heat, causing nucleation of carbon-based particles 100A, ultimately synthesizing carbon-based particles 100A and / or carbon-based particles similar to them as a whole. In the thermal reactor, at least some of the observed nucleation of carbon-based particles can occur on the walls or the heating elements themselves. Nevertheless, particles small enough to be broken down by the flow gas velocity can also nucleate, where these particles are captured to aid in the production of carbon-based particles 100A.

[0148] Pyrolysis of carbon can be used to produce carbon nano-onions (CNO) and / or other fullerenes, as well as smaller amounts of carbon with fullerene internal crystallinity. In a comparative synthesis of carbon-based particles 100A via microwave and thermal reactors, the following differences have been observed: [●] Microwave reactors offer tuning capabilities suitable for providing a wider range of carbon allotropes; and [●] Thermal reactors tend to allow for fine-tuning of process parameters such as heat flow, temperature and / or similar parameters to achieve the specific end-use application goals of carbon-based particles 100A.

[0149] For example, thermal reactors are currently used to construct LiS electrochemical cell electrodes, such as anodes and cathodes. Typical process temperatures range from thousands of Kelvin to produce carbon-based particles 100A and / or associated carbon-based aggregates with conductivity greater than 500 S / m, greater than 5,000 S / m, or between 500 S / m and 20,000 S / m when compressed. Optimal performance has been observed between 2,000 and 4,000 K. [ Carbon-based particles ] [ - ] [ Physical properties and implementation ]

[0150] Any of the carbon-based structures shown in Figures 1A-1F can be incorporated into the electrodes of a secondary battery pack, such as a lithium (Li)-ion battery pack, as substantially described in Lanning et al., “Lithium Ion Battery and Battery Materials,” U.S. Patent Publication No. 2019 / 0173125, published June 6, 2019, which is incorporated herein by reference in its entirety. The disclosed embodiments generally concern the presence or infusion of Li within the anode, but carbon-based systems can be modified for compatibility and integration with the cathode, particularly in LiS systems where S-micrometer confinement is required to reduce unwanted polysulfide (PS) shuttle and battery self-discharge.

[0151] Particulate carbon contained in and / or otherwise associated with carbon-based particles 100A can be implemented as a structural and / or conductive material in the anode or cathode of a Li-ion battery pack, characterized by a hierarchical porous network 100E with a wide pore size distribution, also known as a multi-peak pore size distribution. For example, in addition to or as a substitute for the interconnected microstructure 107E shown in Figure 1E, the particulate carbon may contain at least partially pores that further define an open porous support 102A with one or more diffusion paths 109E, exhibiting a multi-peak pore distribution. The size of these pores may be 0.1 nm to 10 nm, 10 nm to 100 nm, 100 nm to 1 μm, and / or greater than 1 μm. The pore structure may contain pores with a multi-peak size distribution, including smaller pores with a size of 1 nm to 4 nm and larger pores with a size of 30 nm to 50 nm. The multi-peaked pore size distribution in carbon-dominant particles 100A can be beneficial in the assembly of LiS battery systems, where the S-containing cathode in the LiS battery can be confined within pores 105E with a size of approximately less than 1.5 nm or between 1 nm and 4 nm (size 103E). Control of the saturation and crystallinity of S and / or the generated S compounds in carbon-dominant cathodes, including interconnected microstructures 107E within larger pores or pathways in the size range of 30 nm to 50 nm, or pores with a size greater than twice that of solvated lithium ions, can enable and / or promote the rapid diffusion or mass transfer of solvated Li ions (such as lithium (Li) ions 108E) in the cathode.

[0152] As previously described, the lithium-sulfur battery pack, abbreviated as Li-S battery pack, is a type of rechargeable battery pack known for its high specific energy. The Li-S battery pack may include sulfur (S) confined within pores 105E and along the exposed surfaces of the interconnected microstructures 107E of the mesoporous particles 100D by impregnation or potting. Thus, S can be deposited within the open porous support 102A when incorporated into the cathode of the Li-S battery pack, on the surfaces of the carbon-dominant particles 100A, 100D and / or within the interconnected microstructures 107E, as illustrated in Figure 1E and schematic diagram 100F in Figure 1F, which shows the intermediate steps associated with the reduction of sulfur to sulfur ions (S2-). [ Carbon-based particles ] [ - ] [ through ] [ Formation to solve polysulfide ] [ (PS) ] [ Related challenges ]

[0153] To address at least some of the challenges associated with such polysulfide (PS) systems, carbon-based particles 100A and cathode active materials are formed into a meta-particle framework, wherein elemental sulfur, such as that which can form PS compound 100F as shown in Figure 1F, is arranged within carbon pores / channels, such as any one or more of the interconnected microstructures 107E shown in Figure 1E, including pores 104E, 105E and / or pathways 106E and / or diffusion pathways 109E. For example, S can represent a loading level of 35-100% by weight / volume of the active material in the total carbon-based particles 100A and / or 100E, substantially within the interconnected microstructures 107E.

[0154] This type of organized particle architecture can provide low-resistance electrical contact between the insulating cathode electroactive material, such as element S, and the current collector, while providing a relatively high exposed surface area structure. This relatively high exposed surface area structure is beneficial to the overall specific capacity and can assist in enhancing the micron-level confinement of Li ions, such as by forming LiS compounds temporarily retained in the interconnected microstructures 107E, such as in the pores 105E, to subsequently control and guide Li ion migration that may be related to current conduction in the battery pack electrodes and / or system. The implementation of carbon-based particles 100A can also be achieved by using adapted structures, such as those shown by the interconnected microstructures 107E, to effectively prevent their unwanted migration through the electrolyte to the anode, generating unwanted parasitic chemical reactions associated with battery pack self-discharge, thereby capturing at least some of the resulting polysulfides and benefiting cathode and anode stability. [ Li S ] [ Polysulfides during battery system use ] [ (PS) ] [ Of ] [ migrate ] [ ]

[0155] As previously described, referring to the PS shuttle mechanism observed in Li-S battery electrodes and / or systems, PS is well dissolved in the electrolyte. This gives another characteristic of Li-S batteries, namely the shuttle mechanism. PS Sn2, which forms and dissolves at the cathode, diffuses to the Li anode and is reduced to Li2S2 and Li2S. PS species Sn2- formed at the cathode during discharge dissolves in the electrolyte there. This causes PS to diffuse toward the anode relative to the concentration gradient at the anode. PS gradually distributes in the electrolyte. Subsequently, higher PS species react with these compounds to form lower polysulfides S(nx). This means that the chemical reactions required for sulfur at the cathode also occur in part uncontrolled at the anode, where conceivable chemical and electrochemical reactions occur, which negatively impacts the overall battery characteristics.

[0156] If lower-order PS species form near the anode, they diffuse to the cathode. During battery discharge, these diffused species are further reduced to Li₂S₂ or Li₂S. Therefore, during discharge, or more precisely, during battery self-discharge, the cathode reaction partially occurs at the anode. Both are undesirable effects that reduce specific capacity. In contrast, diffusion to the cathode during charging is followed by the re-oxidation of PS species from lower to higher orders. Subsequently, these PS diffuse back to the anode. This cycle is generally referred to as a highly pronounced shuttle mechanism, which can potentially allow the battery to accept an unlimited charge and undergo a chemical short circuit. Generally, the shuttle mechanism results in the loss of parasitic sulfur active material. This is due to the uncontrolled separation of Li₂S₂ and Li₂S outside the cathode region, ultimately leading to a significant reduction in battery cycle capacity and a significantly shortened lifespan. Another aging mechanism can be the heterogeneous separation of Li₂S₂ and Li₂S on the cathode due to volume changes during battery reactions, or the mechanical splitting of the cathode structure. [ The pores of carbon-based particles confine sulfur and prevent it from being trapped. ] [ PS ] [ shuttle to the anode ] [ ]

[0157] To address the PS shuttle phenomenon, one or more of the interconnected microstructures 107E of the carbon-dominant particles 100A in the cathode can provide regions of appropriate size, such as pores 105E with a size 103E less than 1.5 nm, to drive the formation of lower polysulfides such as S and Li₂S, and thus prevent the formation of higher soluble polysulfides LixSy (where y is greater than 3) that promote Li shuttle (such as loss to the anode). As described herein, the structure of the mixture of particulate carbon and cathode material can be tuned during the formation of particulate carbon in a microwave plasma or thermal reactor. Furthermore, the solubility and crystallinity of cathode electroactive materials such as elemental sulfur, which are associated with Li phase formation, can be confined within / captured within the micropores and / or mesopores of the interconnected microstructures 107E of the carbon-dominant particles 100A.

[0158] Multi-peak pore size distribution can indicate that a structure has a high surface area and a large number of small pores, which are effectively connected to the matrix and / or current collectors by material in the structure with larger characteristic sizes to provide more conductive paths through the structure. Some non-limiting examples of such structures are fractal structures, dendritic structures, branching structures, and aggregated structures with interconnected channels of different sizes composed of generally cylindrical and / or spherical pores and / or particles.

[0159] The exemplary particulate carbon materials used in Li-ion or LiS battery packs described herein are described in U.S. Patent No. 9,997,334, entitled "Seedless Particles with Carbon Allotropes," which is assigned to the same assignee as this application and is incorporated herein by reference. The particulate carbon materials may contain a graphene-based carbon material comprising multiple carbon aggregates, each carbon aggregate having multiple carbon nanoparticles, each carbon nanoparticle including graphene, optionally including multi-walled spherical fullerenes; and optionally lacking seed particles, such as nucleating particles. In some cases, the particulate carbon materials are also produced without the use of a catalyst. The graphene in the graphene-based carbon material has up to 15 layers. The ratio of carbon to elements other than hydrogen in the carbon aggregates is greater than 99%. The median size of the carbon aggregates is 1 micrometer to 50 micrometers or 0.1 micrometers to 50 micrometers. When measured using the Brunauer-Emmett-Teller (BET) method with nitrogen as the adsorbate, the surface area of ​​the carbon aggregates is at least 10 m² / g or at least 50 m² / g, or between 10 m² / g and 300 m² / g, or between 50 m² / g and 300 m² / g. When compressed, the carbon aggregates have an electrical conductivity greater than 500 S / m or greater than 5,000 S / m, or between 500 S / m and 20,000 S / m. [ The difference between carbon-based particles and conventional technologies ]

[0160] Conventional composite Li-ion or LiS battery electrode assembly can be made from a slurry casting mixture of active materials, including conductive additives such as fine carbon black and graphite used in specific proportions in the battery cathode, and polymer-based binders optimized to produce a unique self-assembly morphology defined by an interconnected conductive network. In conventional preparation or application, the additives and binders can be optimized to improve conductivity by, for example, providing lower interfacial resistance, and thus correspondingly improving electrical performance and delivery. This also means that specific (also known as gravitational) energy and density must be reduced, which is an undesirable parasitic bulk in current high-efficiency battery applications.

[0161] To minimize losses due to parasitic bulk, such as those caused by increasing the effective and / or ineffective ratio, and simultaneously to allow the electrolyte to reach the complete surface of the electrode more quickly, the diffusion path 109E can be reoriented to effectively shorten the Li ion diffusion path length used for charge transfer. Hierarchical pores 101A and / or open porous supports 102A can be generated from carbon particles of reduced size and / or active materials down to the nanoscale. Specific surface area (SSA), defined as the total surface area of ​​the material per unit mass (m² / kg or m² / g) or solid or total volume (m² / m³ or m⁻¹), is a physical value of any one or more of the carbon particles disclosed in this invention that can be used to determine the material type and properties. For example, the SSA of spheres increases as the diameter decreases. However, when the particle size decreases to the nanoscale range, there are associated attractive van der Waals forces that can hinder dispersion, promote aggregation, and thereby increase battery impedance and reduce power efficiency.

[0162] Another method for shortening ion diffusion paths (referring to diffusion path 109E shown in Figure 1E) is to uniquely engineer the constituent carbon-based particles, such as the internal porosity of the constituent carbon-based particles generated by the aggregate 101B used to generate the interconnected microstructure 107E. Surface curvature can be referred to as porosity, which is true when the cavity depth is greater than its width. Therefore, this definition must exclude many nanostructured carbon materials in which only the outer surface area is modified, or in which voids such as specific internal spaces or regions are tightly encapsulated particles generated between adjacent particles, as in the case of conventional slurry-cast electrodes.

[0163] Regarding the engineering modifications described previously, which refer to the synthesis, production, formation, and / or growth of carbon-based particles 100A in a microwave-based reactor or via layer-by-layer deposition in a thermal reactor, the reactor process parameters can be adjusted to tune the size, geometry, and distribution of the hierarchical pores 101A and / or interconnected microstructures 107E within the carbon-based particles 100A. The hierarchical pores 101A and / or interconnected microstructures 107E within the carbon-based particles 100A can be adapted to achieve performance profiles particularly well-suited for implementation in high-efficiency, fast-current delivery devices such as supercapacitors.

[0164] As previously described, a supercapacitor (SC), also known as an ultracapacitor, is a high-capacitance capacitor that bridges the gap between an electrolytic capacitor and a rechargeable battery pack, with a capacitance much higher than other capacitors but a lower voltage limit. It typically stores 10 to 100 times more energy per unit volume or mass than an electrolytic capacitor, can accept and transfer charge much faster than a battery pack, and can accommodate far more charge and discharge cycles than a rechargeable battery pack.

[0165] Many of the readily available commercial carbons used in early supercapacitor development exhibit worm-like narrow pores that become bottlenecks or disadvantages when operating at high current densities and rapid charge and discharge rates. This is because electrons may encounter difficulties flowing through or around these structures or pathways. Even though the pore size is extremely uniform and can still be tuned to accommodate a wide range of length scales, the actual achievable performance remains limited by the inherent structural challenges of worm-like narrow pores.

[0166] Compared to conventional porous materials with uniform pore sizes tuned to a wide range of length scales, the 3D hierarchical porous materials disclosed in this invention, such as those exhibited by hierarchical pores 101A and / or interconnected microstructures 107E within carbon-dominant particles 100A, can be synthesized to have well-defined pore sizes, such as interconnected microstructures 107E including pores 104E, 105E and / or paths 106E and / or diffusion paths 109E, and topological structures, to overcome the shortcomings of conventional single-sized porous carbon particles by generating multi-peaked pores and / or channels with the following sizes and / or widths: ● Medium (2 nm < d-pore size < 50 nm) pore size; ● Large (d-pore size > 50 nm) pore size 201A, to minimize diffusion resistance to mass transport; and ● Micro (d pore size < 2 nm) pores 202, to increase the surface area for active site dispersion and / or ion storage, and the capacitance related to the ion density and number that can be stored in a given pore size, such as the pore size 105E with size 103E shown in Figure 1E.

[0167] Although a simple linear correlation between surface area and capacitance has not yet been experimentally established, carbon-based particles 100A offer optimal micropore size distributions and / or configurations for various intended end-use applications and corresponding voltage windows. To optimize capacitive performance, carbon-based particles 100A can be synthesized with extremely narrow pore size distributions (PSDs); and larger pores are preferred as the required voltage increases. In any case, current advanced supercapacitor technology provides pathways for engineering the 3D hierarchical structured materials disclosed in this invention for specific end-use applications.

[0168] In supercapacitors, capacitance and electrical performance are primarily controlled by factors such as: the surface area of ​​the pore walls; the pore size; and the interconnectivity of the pore channels that affect the electrical double-layer performance.

[0169] In contrast, Li-ion and / or Li-S storage battery packs undergo faradaic reduction / oxidation reactions within the active material, thereby requiring numerous Li-ion transport components, such as supercapacitors that effectively orient and / or shorten the Li-ion diffusion path. However, in any application, including supercapacitors and conventional Li-ion or Li-S secondary battery packs, 3D nanocarbon-based frameworks / architectures, such as the 3D nanocarbon-based framework / architecture defining the open porous scaffold 102A, can provide continuous electrical conduction paths, such as across and along the conductive interconnect aggregates 101B of the graphene sheet, alongside highly loaded active materials, for example, with high areal and volumetric specific capacities. [ Carbon-based particles used as cathode forming materials ] [ ]

[0170] To address the issues of relatively low electrical and ionic conductivity, volume expansion, and the prevalence of polysulfide (PS) dissolution in current LiS cathode electrode designs, carbon-based particles 100A are incorporated with hierarchical pores 101A and / or interconnected microstructures 107E forming therein to define an open porous scaffold 102A. This open porous scaffold 102A includes pores 105E with micropore structures of sizes 103E suitable for limiting elemental sulfur and / or LiS-related compounds, such as cavities of approximately less than 1.5 nm or 1-4 nm. The open porous scaffold 102A also provides a host scaffold structure for managing sulfur expansion through, for example, in-situ nitrogen (N) doping of adapted carbon (C) within a reactor, thereby ensuring electron conduction across sulfur-carbon (SC) interfaces, such as at the contact and / or interface regions of S and C within pores 105E. Confining S within a nanometer (nm) scale cavity, such as a pore 105E with a microporous texture 103E, advantageously alters both of the following: [●] Equilibrium saturation, such as the solubility product; and [●] The crystallization behavior of S is such that the electrical conduction required during the dissociation of LiS compounds is possible, and S is kept confined within a microporous texture or pore size of 103E or 105E without the external power required for the uncontrolled migration of PS to the anode electrode.

[0171] Therefore, the size 103E of the pores 105E results in a spacer that does not need to attempt to impede the diffusion of polysulfides (PS), while negatively affecting the battery impedance caused by the combination of ohmic resistance and reactance, as well as polarization, such as the effective resistance of a circuit or component to alternating current. By using carbon with optimal and non-optimal multi-peak pore distributions (referring to interconnected microstructures 107E including pores 104E, 102E, and / or 103E) or (alternatively) bi-peak pore distributions relative to the micrometer confinement of elements S, Li, and / or LiS, the carbon-dominant particles 100A exhibit an operating principle of micrometer confinement in a properly optimized structure.

[0172] These optimized structures include and contain polymers 101B, which can be prepared to include parallel stacked graphene layers, such as parallel stacked graphene layers produced from graphite with strong (002) dimensions to random few-layer (FL) graphene with low (002) dimensions and nanoscale porosity. Figures 1G and 1H show the system of Li ions sandwiched between the carbon lattice and structure within the individual graphene layer cells in Figure 1G and in the intermediately adjacent and parallel graphene layers in Figure 1H. The assembly shown in Figure 1H may include multiple stages, including stages 1 to 3, each state representing graphene layer planes of various sizes and spacing levels to produce a theoretical specific capacity of approximately 372 mAh / g or greater at the cathode.

[0173] Figure 2 illustrates the evolution beyond the conventional adjacent stacked FL graphene layers shown in stages 1 to 3 of Figure 1H, where cavities are formed extending to a depth within several adjacent stacked FL graphene layers, each layer having a tunable D-spacing in the range of approximately 3.34 Å to 4.0 Å or 3 Å to 20 Å. Therefore, Li ions can be intercalated between adjacent graphene layers and on the exposed surfaces of cavities, also known as nanopores, to produce a specific capacity range exceeding 750 mAh / g. According to some embodiments, when observed together, exemplary 3D self-assembled binderless carbon-based particles can be agglomerated to form carbon-based networks, lattices, scaffolds, or particles that may include one or more of the carbon-based structures shown in Figures 1A to 1E. The carbon-based networks may include one or more of a plurality of macropores or micropores 202.

[0174] The carbon-based particles 100A also provide the ability to effectively load or infuse the carbon support 300 shown in FIG. 3 with elemental Li, such as elemental Li provided by molten Li metal or its vapor derivatives. The carbon support 300 can be generated in the reactor by: depositing multiple carbon-based particles 100A layer by layer by a slurry process; or, as shown by the plasma torch system 400B in FIG. 4B, by a set of plasma torches having a continuous sequence of sulfur, such as elemental sulfur.

[0175] For LiS battery packs to reliably outperform conventional Li-ion battery packs, industrially scalable technologies must achieve high sulfur loadings, such as >70% sulfur / unit volume, relative to all additives and components of a given cathode template, while maintaining the natural specific capacity of the sulfur active material. Attempts to incorporate sulfur into the cathode bulk through electrolysis, wet chemistry, simple mixing, ball milling, spraying, and any one or more of the cathode electrolyte have been incomplete as needed and are either economically unscalable or unmanufacturable in other ways.

[0176] Unlike melt wetting, which is thermodynamically unattainable in small pores, the synthesis method disclosed in this invention utilizes isothermal vapor technology introduced and reacted at substantially atmospheric pressure. The high surface free energy of nanoscale pores or surfaces drives the spontaneous nucleation of sulfur-containing liquids until a conformal coating of sulfur- and / or lithium condensates reaches the inner surface of the hierarchical pores 101A and / or connected microstructures 107E. Essentially, the unique vapor infusion method infuses sulfur into fine pores, such as any or more of the hierarchical pores 101A and / or connected microstructures 107E and / or pores 104E, 105E and / or pathways 106E and / or diffusion pathways 109E at the nuclei of carbon-dominant particles 100A, and therefore not only at their surfaces. [ Carbon-based particles used to generate conductive scaffolds ] [ ]

[0177] Carbon-based particles 100A can be manufactured in any number of ways using known techniques and novel techniques disclosed herein, including: [●] Slurry casting refers to a conventional metalworking, manufacturing, and / or manufacturing technique in which liquid material is typically poured into a mold containing a hollow cavity of a desired shape and subsequently solidified; or [●] Plasma torch system 400B, such as the plasma torch system 400B shown in Figure 4B, can be used to perform layer-by-layer deposition to gradually grow carbon-based particles 100A.

[0178] Any of the techniques described above, or any other known or novel manufacturing techniques, can be used to produce the carbon scaffold 300 shown in Figure 3 in a graded manner. Control of the electrical gradient, as specified at least partially by any one or more of the electrical gradient and ion conduction gradient described below, can produce a carbon scaffold 300 with varying conductivity. ● The electrical gradient can be defined by graphene sheets 101B that are substantially orthogonally fused together to form an open porous scaffold 102A, wherein electrical conduction occurs along and across the contact points of the graphene sheets 101B; and ● Ion conduction gradients, such as those for Li ion transport, movement, or migration through hierarchical pores 101A and connected microstructures 107E, can benefit in certain configurations of carbon-dominant particles 100 by the effective shortening of diffusion paths 109E in the vertical height direction A throughout the thickness of the carbon support 300B, as shown in FIG3B. This effective shortening is used, for example, to allow Li ions sandwiched between adjacent few layers of graphene sheets, such as graphene sheets 101B, to escape en route toward the liquid electrolyte surrounding the carbon support 300B and migrate to the cathode-cured electrochemical cell discharge-charge cycle.

[0179] Throughout the embodiments disclosed in this invention, various forms of carbon are mentioned in the synthesis within a reactor to produce graphene sheets 101B, which are interconnected and conduct electricity along contact points and can undergo changes in shape, size, position, orientation, and / or structure. These changes can affect crystallinity differences and one or more specific types of carbon allotropes used to produce the conductive interconnect aggregates 101B of the graphene sheets. Crystallinity refers to the degree of structural order in a solid. In a crystal, atoms or molecules are arranged in a regular, periodic manner. Therefore, crystallinity has a significant impact on hardness, density, transparency, and diffusion.

[0180] Therefore, carbon-based particles 100 can be generated outside the reactor, such as in the form of a carbon-based scaffold via a tissue scaffold, or during post-processing activities outside the main synthesis within the reactor.

[0181] As disclosed in Stowell et al., "Microwave Chemical Processing Reactor," U.S. Patent No. 9,767,992, published on September 19, 2017, plasma processing and / or plasma-based processing can be carried out in a reactor, wherein a supply gas system is used to generate plasma in the plasma zone to convert process input materials such as methane and / or other hydrocarbons suitable for the gas phase into separated components in the reaction zone, thereby promoting the ongoing synthesis of carbon-based materials.

[0182] As an alternative to synthesis via or within a microwave reactor as described above, thermal energy can be directed toward or near a carbon-containing feedstock supplied in the gas phase onto a sacrificial substrate 306 of the carbon support 300 shown in Figure 3 to sequentially deposit multiple layers of carbon-based particles 100A via, for example, a plasma torch system 400B shown in Figure 4B. These particles can be fused together in operation within a microwave reactor or deposited in a controlled manner within a thermal reactor to achieve varying concentration levels of the carbon-based particles 100A, thereby subsequently achieving graded conductivity proportional to the concentration levels of the carbon-based particles 100A in the carbon support 300. These procedures can be used to formulate porous carbon-based electrode structures such as the carbon support 300, which offer high tunability in conductivity and ion transport, while eliminating many generation steps and otherwise preserving a conventional external appearance.

[0183] An open porous scaffold 102A with an open honeycomb structure can be produced so that a liquid electrolyte can be easily wetted into various pores therein, such as pathways, voids, and one or more of the like in interconnected microstructures 107E. The framework portion of the open porous scaffold 102A can be referred to as a substrate or framework, and the pores such as the hierarchical pores 101A and / or the interconnected microstructures 107E can be wetted with fluids, liquids, or gases, while the framework material is typically formed as a solid material. [ Porosity of carbon-based particles ] [ ]

[0184] The characteristics of porous media, such as carbon-based particles 100A, can be attributed to their porosity. Other properties of the medium, such as permeability, tensile strength, conductivity, and tortuosity, can be derived from its composition, the solid matrix and fluid dispersed therein, and the corresponding characteristics of the medium's porosity and pore structure. Carbon-based particles 100A, with interconnected microstructures 107E dispersed throughout, can be generated outside the reactor to achieve the required porosity level to facilitate Li ion diffusion. Related to this Li ion diffusion, graphene sheets 101B promote electron conduction along their contact points, while also allowing electrons to recombine with positive Li ions at reaction sites.

[0185] Regarding the porosity and tortuosity of the open porous scaffold 102A of carbon-based particles 100A, marble analogues can be fabricated in a glass bottle. In this example, porosity refers to the distance between marbles that allows a liquid electrolyte to permeate into the interstices of the interconnected microstructures 107E that define diffusion paths 109E within the carbon-based particles 100A. The marble itself can resemble Swiss cheese by allowing the electrolyte to permeate not only into the cracks between graphene sheets 101B but also into each graphene sheet itself, as shown in Figure 1C. In this and other examples, the relative shortening of the diffusion path 109E refers to the time it takes for Li ions to infiltrate therein via, for example, capillary action, to contact active materials such as S confined within pores 105E. The diffusion path 109E is adapted to facilitate the convenient and rapid wetting and diffusion of Li-ion-containing electrolytes into carbon-based particles 100A, which can then be grown or otherwise synthesized to produce a carbon scaffold 300 with hierarchical conductivity.

[0186] The shortening of diffusion path 109E refers to the reduction in the diffusion length of active materials such as S, which move through the open porous support 102A within the carbon support 300 without being confined within the pores 105E of the interconnected microstructure 107E. This contrasts with conventional techniques that require shortening the diffusion length of active materials simply by reducing the thickness of the active material. The diffusion path 109E within the interconnected microstructure 107E can act as a Li-ion buffer reservoir by controlling the flow and / or transport of Li-ions therein, providing a freer flow structure for Li-ion transport, such as for Li-ion transport during the reaction with the exposed carbon surface of the S-coated pores 105, and later during the charge-discharge cycle of the electrochemical battery, which may benefit Li-ion confinement. The transport of Li ions along diffusion path 109E in the general direction shown in Figure 1E can occur in the liquid electrolyte initially infused and captured within the open porous support 102A, wherein the electrolyte infusion occurs prior to the use of the annular carbon support 300 in the discharge-charge cycle.

[0187] Examples include: allowing the initial diffusion and distribution of a liquid electrolyte within an open porous scaffold 102A of carbon-based particles 100A to fill and occupy the hierarchical pores 101A and / or interconnected microstructures 107E, followed by the use of a carbon scaffold 300 synthesized or otherwise produced by layer-by-layer deposition of the carbon-based particles 100A. Vacuum or air can also be used to fill the hierarchical pores 101A and / or interconnected microstructures 107E, which allows or facilitates the wetting of the electrolyte on the exposed carbon surfaces within the open porous scaffold 102A.

[0188] Li ions bounce from one location to another via a chain reaction, similar to the impact of a Newton's ball, where one ball strikes and causes a force transfer, thus moving other balls. Similarly, individual Li ions move relatively short distances, but a large number of Li ions can still move collectively via chain reactions of this type as described. As can be seen from the crystalline arrangement of Li ions and / or particles within, around, or in the aggregate 101B of the graphene sheet, the degree of movement of individual Li ions can be influenced by the amount of Li ions supplied to the carbon scaffold 300B along with the aggregate via capillary infusion into the open porous scaffold 102A. [ Electrochemical cell anode or cathode generated by carbon support ] [ ]

[0189] The carbon support 300 shown in Figure 3 can be integrated into battery packs or supercapacitor applications, including Li-ion battery packs and LiS battery packs. The carbon support 300 can be incorporated into the anode or cathode for use in Li-ion and LiS battery pack systems, but interconnected microstructures 107E need to be fabricated to confine S within pores 105E or elsewhere to accommodate the generation and confinement of polysulfides (PS) and control PS migration. An exemplary battery pack system may include an electrochemical cell assembled to supply power to the system. The electrochemical cell may have an anode containing anodic active material, a cathode containing cathodic active material, a porous spacer disposed between the anode and cathode, and an electrolyte in ionic contact with the anodic and cathodic active materials.

[0190] The anode and cathode may include a conductive sacrificial substrate 306, wherein a first layer is deposited on the first interconnected film when the first interconnected film has a first concentration of carbon-based particles 100A, which are shown as carbon-based particles 302 in FIG3 for the purpose of omitting redundant descriptions.

[0191] A porous configuration is formed in a carbon scaffold 300 defined by carbon-dominant particles 302, which are synonymous with and interchangeable with adjacent carbon-dominant particles 100A, and smaller carbon particles 304 are distributed throughout the carbon scaffold 300. The porous configuration of the carbon scaffold 300 accommodates electrolytes dispersed therein for Li-ion transport via interconnected hierarchical pores 101A and / or interconnected microstructures 107E that define one or more channels similar to the individual carbon-dominant particles 100A and / or 302. These one or more channels include: [●] Provides a tunable Li ion channel with a microporous framework defined by a size > 50 nm (101E); [●] A mesoporous channel, defined by a size of approximately 10²E (generally defined according to IUPAC nomenclature and referred to as a mesoporous channel or mesoporous channel) of approximately 20 nm to approximately 50 nm, serving as a high-speed Li-ion channel for rapid Li-ion transport; and [●] Microporous texture defined by a size of < 4 nm 103E for charge storage and / or active material confinement.

[0192] A first layer comprising a first concentration of carbon-based particles 100A and / or 302 can be configured to exhibit conductivity in the range of 500 S / m to 20,000 S / m. A second layer or any subsequent layer can be deposited on the first layer or any preceding layer. The second layer may comprise a second interconnected film formed by a second concentration of mutually contacting carbon-based particles 100A and / or 302 to produce a second conductivity in the range of 0 S / m to 500 S / m or otherwise lower than the first conductivity.

[0193] The carbon scaffold 300 can be prepared for subsequent Li wetting, referred to herein as pre-lithiation, and subsequently perfused with a Li ionic liquid solution via capillary action to produce the lithiated carbon scaffold 400A as shown in Figure 4A. Films 406A, 408A, 410A, and 412A, each having a defined thickness in a vertical direction extending from the current collector, can be synthesized in operation in a microwave reactor or deposited layer-by-layer in or outside a thermal reactor. Films 406A, 408A, 410A, and 412A have varying conductivity in a direction orthogonal to and away from the current collector, ranging from high at film 406A to low at film 412A, which can also be a sacrificial and / or conductive substrate. In one exemplary configuration, layers 406A, 408A, 410A, and 412A of films having defined and progressively decreasing concentrations of carbon-based particles 302 can be produced to achieve specific resistance values, such as in the following cases: ● A film layer 406A is produced having a relatively high defined concentration of carbon-based particles 302. This relatively high defined concentration of carbon-based particles 302 contributes to low Li ion transport and low resistance (< 1,000 Ω), making it suitable for high conductivity. ● Films 408A and 410A with systematically reduced conductivity are produced by engineering carbon-based particles 302 to exhibit the required interfacial surface tension to promote the wetting of molten Li metal on the exposed carbon surface; and ● A film layer 412A is generated with a relatively low defined concentration of carbon-based particles 302, which facilitates high Li ion transport and high resistance > 1,000-10,000 Ω, making it suitable for high resistance applications.

[0194] The varying conductivity can be at least partially proportional to the interfacial surface tension of the Li ion solution impregnated in the porous configuration of the open porous scaffold. Li ion solution impregnation (e.g., including Li ions 108E) can be performed via capillary infusion engineered to facilitate surface wetting of the open porous scaffold 102A exposed to the Li ion solution. The diffusion path 109E, as shown in Figure 1E, ensures uniform deposition and stripping operations associated with one or more oxidation-reduction (also known as redox) reactions occurring within the carbon-dominant particles 100A and / or 302B. The electroactive material can reside in the pores 105E of the associated microstructure 107E during its use in forming the open porous scaffold 102A, which itself can be located within either or more of the anode and cathode. In some embodiments, the interconnected microstructure 107E may be formed from or otherwise contain: monolayer graphene (SLG) as shown in FIG1C and / or few-layer graphene (FLG) comprising 1 to 10 graphene planes in the aggregate 101B of the multilayer graphene sheets 101C shown in FIG1B. The group of graphene sheets 101C may be substantially aligned and oriented along the vertical axis and fused together at substantially orthogonal angles. The anodic or cathodic active material may have a specific surface area of ​​approximately 500 m² / g to 2,675 m² / g when measured in a dry state, and may contain graphene material suitable for lithiation, the graphene material comprising one or more of the following: pre-lithiated graphene sheets, initial graphene, graphene oxide, reduced graphene oxide, fluorinated graphene, chlorinated graphene, brominated graphene, iodinated graphene, hydrogenated graphene, nitrided graphene, boron-doped graphene, nitrogen-doped graphene, chemically functionalized graphene, its physical or chemical activation or etching type, its conductive polymer coating or grafting type, and / or combinations thereof.

[0195] In any one or more of the examples discussed in relation to the lithium-carbon scaffold 400A, the conductive interconnect polymers 101B of the graphene sheets are sintered together to form an open porous scaffold independent of an adhesive; however, there are alternative examples in which an adhesive is used. Combinations using or not using an adhesive may each relate to an open porous scaffold 102A acting as an active lithium interlayer structure with a specific capacity of about 744-1,116 mAh / g or greater. Furthermore, examples include the preparation of graphene sheets 101B using chemically functionalized graphene, which involves surface functionalization comprising imparting functional groups selected from quinones, hydroquinones, quaternary ammonium aromatic amines, thiols, disulfides, sulfonates (-SO3), transition metal oxides, transition metal sulfides, other similar compounds, or combinations thereof, to the open porous scaffold 102A.

[0196] The current collector shown in Figure 4A is, for example, at least partially based on or derived from a foam and may be selected from any one or more of the following: metal foam, metal mesh, metal screen, perforated metal, sheet-based 3D structure, metal fiber pad, metal nanowire pad, conductive polymer nanofiber pad, conductive polymer foam, conductive polymer coated fiber foam, carbon foam, graphite foam, carbon aerogel, carbon dry gel, graphene foam, graphene oxide foam, reduced graphene oxide foam, carbon fiber foam, graphite fiber foam, exfoliated graphite foam, and combinations thereof.

[0197] The anodic or cathode conductive or insulating materials referred to herein as active materials may include any or more of the following inorganic materials: nanodisks, nanosheets, nanofullerenes, carbon nanotubes (CNOs), nanocoatings, or nanosheets: [●] Bismuth selenide or bismuth telluride, [●] Transition metal disulfides or trisulfides, [●] Transition metal sulfides, selenides, or tellurides; [●] Boron nitride or [●] Its combination includes molten Li metal dispersed therein to provide a Li ion source during dissociation during normal electrochemical battery discharge-charge cycle, etc.

[0198] The thickness of nanodisks, nanosheets, nanocoatings, or nanosheets may be less than 100 nm. In other examples, the thickness of nanosheets may be less than 10 nm and / or the length, width, or diameter may be less than 5 µm. [ Anodes or cathodes produced by carbon structures ] [ ]

[0199] An exemplary method for producing three-dimensional (3D) carbon-based electrodes, such as electrodes produced by a lithium-carbon scaffold 400A, may include depositing carbon-based particles 100A or 400A on a substrate, such as layer 406A as shown in FIG. 4A, by means of one or more plasma-based thermal reactors or torches from which thermal energy is transferred via plasma and / or supplied in a gaseous state, to form a first interconnected film layer, wherein the first interconnected film layer is characterized by a first conductivity. Each of the carbon-based particles comprises conductive three-dimensional (3D) aggregates or agglomerates 101B of graphene sheets. The aggregates may be orthogonally fused together to form an open porous scaffold 102A to facilitate electrical conduction along and across the contact points of the graphene sheets.

[0200] A porous configuration is formed in an open porous scaffold 102A, wherein the porous configuration facilitates the reception of electrolytes dispersed therein for Li ion transport via interconnecting pores defining diffusion paths 109E, such as hierarchical pores 101A and / or interconnected microstructures 107E. The average thickness of the first interconnected film layer is no greater than about 100-200 µm. In one example, an adhesive material is combined with a graphene sheet 101B to retain the graphene sheet 101B in an ideal position to impart the structure with an open porous scaffold 102A. The adhesive may be or comprise a thermosetting resin or a polymerizable monomer, wherein the resin or polymerizable monomer is cured under the assistance of heat, radiation, an initiator, a catalyst, or a combination thereof to form a solid resin or polymer. The adhesive may initially be a polymer, coal tar pitch, petroleum pitch, mid-phase pitch, or an organic precursor material and subsequently thermally converted into a carbon material.

[0201] Additional carbon-based particles 100A are deposited on the first interconnected film layer to form a second interconnected film layer thereon. The second interconnected film layer has a second conductivity lower than the first conductivity and is closer to the electrolyte 414A and farther away from the current collector positioning that can serve as a sacrificial substrate. A Li ion solution can be impregnated into the open porous scaffold 102A, for example by capillary perfusion, to react with the exposed carbon on its surface to promote Li ion dissociation and current supply, wherein the exposed carbon on the open porous scaffold can have a surface area greater than about 100 m² / gm.

[0202] Carbon-based particles 100A and / or lithium-carbon scaffolds 400A can be synthesized in operation in a microwave reactor or deposited or grown in a thermal reactor in a bottom-up manner, referring to layer-by-layer deposition, and can then be cast via a subsequently dried liquid slurry to form a carbon-based electrode suitable for implementation in or incorporated into a Li-ion battery pack. In some examples, such slurry may contain chemical binders and conductive graphite as well as electrochemically active intrinsic carbon.

[0203] The term "hierarchical" refers to an arrangement of items that are positioned above, below, or at the same level as each other. Here, carbon-based particles 100A and / or lithium-carbon support 400A can be grown by layer-by-layer deposition in a thermal reactor to produce one or more levels indicated by conductive particles 100A, 302B, and / or 402A film layers 406A to 412A. These levels represent levels generated by specific control of electrical (referring to the contact points of graphene sheet 101B) and ionic (referring to diffusion path 109E) conductivity gradients throughout the thickness of the lithium-carbon support 400A. The tuning of each individual deposited layer 406A to 412A produces relatively high conductivity at the current collector interface and progressively lower conductivity moving outwards from it.

[0204] The graphene sheets 101B within the carbon-dominant particles 100A can act as electrical conductors by conducting current through contact points and / or regions, and serve as an active Li sandwich structure providing a specific capacity source for anode electrodes with specific capacities such as 744-1,116 mAh / g, which are 2 to 3 times the specific capacities otherwise obtained from conventional graphite anodes (e.g., 372 mAh / g). Therefore, the interconnected 3D bundles 102 of graphene sheets within the carbon-dominant particles 100A can be considered as nanoscale electrodes that simultaneously enable relatively high volume fraction electrolytic active materials and efficient 3D interpenetrating ion and electron pathways.

[0205] The unique 3D structure of this carbon-based particle 100A allows it to store charge at its exposed surface via a capacitive charge storage device for high-power delivery, as opposed to conventional applications, and also provides Faraday redox ions within its body for high-energy storage. As generally understood and mentioned herein, redox refers to a reductive oxidation reaction in which the oxidation state of atoms changes, involving electron transfer between chemical species, most often with one species undergoing oxidation and the other undergoing reduction.

[0206] As is generally understood and as mentioned herein, Faraday refers to a heterogeneous charge transfer reaction occurring on the surface of an electrode prepared and / or otherwise containing carbon-based particles 100A. For example, the pseudocapacitor method stores electrical energy in a Faraday manner through electron charge transfer between the electrode and the electrolyte. This is achieved through electroadsorption, redox reactions, and intercalation methods, and is referred to as pseudocapacitor. [ Roll-to-roll processing for battery electrodes produced from carbon substrates ] [ ]

[0207] Regarding manufacturing, the lithium-carbon scaffold 400A can be fabricated and / or used to construct electrochemical battery electrodes such as cathodes and / or anodes by sequentially and layer-by-layer (such as layers 406A to 412A as shown in Figure 4A) depositing a certain concentration of carbon-based particles 100A and / or 100E onto a mobile substrate, such as a current collector, via a roll-to-roll (R2R) production method. By directly bonding the 3D carbon scaffold structure to the outside of a microwave reactor using a method similar to plasma jetting, the electrode film can be continuously produced without the need for toxic solvents and binders used in other slurry casting methods for battery electrode assembly. Therefore, it is easier to generate battery pack electrodes with controlled electrical, ionic, and chemical concentration gradients using a lithium-carbon substrate 400A, which are caused by the layer-by-layer sequential particle deposition capability of the plasma jetting method; and specific elements such as dopants can also be introduced into the plasma deposition process at different stages.

[0208] Furthermore, due to the pores 105E and / or interconnected microstructures 107E dispersed throughout the carbon-based particles 100A, the lithium-based carbon support 400A can be manufactured in a manner superior to known devices via gravity (referring to the set of methods used in analytical chemical reactions for the quantitative determination of analytes based on their mass). That is, the carbon-based particles 100A, having pores and / or voids defined within the 3D bundles 102 and / or conductive carbon particles 104 of the entire graphene sheet, are lighter than comparable battery electrode packs that do not possess a mesoporous structure including various pores and / or voids.

[0209] The carbon-based particles 100A are characterized by a superior ratio of active to inactive material compared to conventional technologies. This is because a larger amount of active material is available and prepared for electrical conduction compared to inactive and / or structurally reinforcing materials. Although the structurally reinforcing material is involved in defining the general structure of the carbon-based particles 100A, it may not be involved in, or may be involved in, the conductive interconnect polymer 101B of the graphene sheet. Therefore, due to its high ratio of active to inactive material, the carbon-based particles 100A exhibit superior conductivity compared to conventional battery packs and are significantly lighter than conventional battery packs, provided that carbon can be used to replace the heavier metals traditionally used. Therefore, the carbon-based particles 100A are particularly well-suited for and can benefit from end-use applications requiring relatively light weight, such as automobiles and light trucks.

[0210] Carbon-based particles 100A can achieve a percolation threshold by generating conductive interconnect aggregates 101B dependent on graphene sheets. This percolation threshold is a mathematical concept in percolation theory describing the formation of long-range connectivity in random systems. There are no large interconnected components below the threshold, but there are large components approximately the system size above the threshold. Therefore, the 3D bundle 101B of graphene conductive interconnect aggregates of the graphene sheets can conduct electricity from the current collector towards the electrolyte 414A, as shown in Figure 4A. [ Volume-to-volume (R2R) ] [ Plasma jetting torch deposition system ] [ ]

[0211] When variations of the atmospheric MW plasma reactor disclosed in this invention are used to produce particle-based outputs including integrated, interconnected 3D hierarchical carbon support membranes, torch assemblies can be used to produce similar carbon-based structures, such as those shown by the roll-to-roll (R2R) system 400V in Figure 4V. Similar to waveguide reactors, the plasma torch allows for the initial formulation of materials, followed by acceleration into impact zones on a movable or stationary substrate surface. The various zones of the R2R method provide unique control over the synthesis, formulation, consolidation, and integration (such as densification) of dissimilar mixed phases or composite materials.

[0212] Plasma torches can be used to deposit carbon-based particles on continuously moving substrates to enable additional process control at the thermal plasma nozzle location, depositing carbon-based particles beyond the plasma afterglow zone to the substrate impact zone. Various characteristics, such as defect density and residual stress, can be controlled by manipulating the film deposition thickness, chemical and thermal gradients, phase transitions, and anisotropy. For electrochemical battery electrode fabrication, atmospheric MW plasma torches can not only produce formulated and integrated continuous 3D graphene films using conventional slurry casting methods without the need for toxic solvents such as NMP and / or binders, but also achieve enhanced performance by producing integrated electrode / current collector film structures at reduced costs.

[0213] Figure 4V shows an exemplary arrangement of roll-to-roll (R2R) systems 400V employing plasma torches of 422V to 428V (groups 444V, such as 422V, 424V, 426V, and / or 428V), all of which are assembled to perform layer-by-layer deposition to gradually fabricate (or otherwise referred to as growth) the carbon-based scaffold 300B and / or variations thereof shown in Figure 3B. A group 444V of plasma jet torches 414V to 420V is directed in a continuous sequence above an R2R processing device 440V, which may include wheels and / or spools 434V and 439V configured to rotate in the same directions 430V and 432V respectively, to cause a forward movement 436V of the sacrificial layer 402V. A layer 442V of carbon support 436V on the sacrificial layer 402V can be deposited layer by layer to achieve a graded electrical conduction gradient proportional to the concentration level of carbon-based particles 100A contained in the regions of each progressively deposited layer per unit volume (such as film layers 406V-412V).

[0214] This deposition may involve a group 444V of plasma jet torches 414V to 420V, as shown in Figure 4B, on which a carbon support 300B is mounted on a sacrificial layer 402V. Initially moving forward at 436V, torch 414V extends downwards from the feed supply line 412V toward the sacrificial layer 404V. The torch 414V is positioned to jet 422V of carbon-based material to deposit the initial layer 404V, which may also be shown as an intermediate layer 406A in Figure 4A, and so on. The initial layer 404V can be deposited to achieve the highest conductivity value, wherein each of the subsequent layers 406V to 410V is characterized by a proportionally less dense dispersion of carbon-based particles 100A of the carbon-based support 300B used to achieve the graded gradient for layer 442V.

[0215] That is, as shown in Figure 4V, the plasma torches 414V to 420V can be oriented to have gradually decreasing or otherwise varied heights, so that each torch from group 444V can be tuned to eject (422V to 428V respectively) carbon-based feedstock material supplied by feedstock supply line 412V. Therefore, it is easier to generate battery electrode packs with controlled electrical, ionic, and chemical concentration gradients caused by the layer-by-layer sequential deposition described herein with respect to plasma torch system 400V, which exhibits the desired characteristics of a plasma-spraying method; and specific elements or additional components can be introduced at different stages within the plasma-based spray deposition process described by plasma torch system 400V. This control extends to the tunability of plasma torch system 400V to achieve target electric and / or electromagnetic field characteristics for any one or more of layers 442V.

[0216] Plasma jet torches in the 414V to 420V group (444V) can employ plasma-based thermally enhanced carbon jetting technology to provide a carbon coating process in which molten or heated materials are sprayed onto a surface. The raw materials for coating precursors are heated by electrical, plasma, or arc or chemical means (such as combustion and / or fire).

[0217] Compared to other coating methods such as electroplating, physical and chemical vapor deposition, thermal spraying, performed by a plasma torch at 414V to 420V, allows for the provision of thick coatings with thicknesses generally ranging from 20 µm to several millimeters over large areas at high deposition rates. Coating materials available for thermal spraying include metals, alloys, ceramics, plastics, and composites. The materials are fed in powder or wire form, heated to a molten or semi-molten state, and accelerated toward the substrate in the form of micron-sized particles. Combustion or arc discharge is typically used as the energy source for thermal spraying. The resulting coating is created by accumulating a large number of sprayed particles. The surface does not heat significantly, allowing the coating of flammable materials.

[0218] Coating quality is typically assessed by measuring its porosity, oxide content, maximum and minimum hardness, bond strength, and surface roughness. Generally, coating quality improves with increasing particle velocity. [ Implemented in ] [ Li S ] [ Carbon support structure in secondary battery packs ]

[0219] Group 444B of plasma jet torches 414B to 420B can be assembled or tuned to spray carbon-based materials in a controlled manner to achieve specific desired hierarchical and structured forms, such as open porous supports 102A and interconnected microstructures 107E for Li-ion-wetted carbon-based particles 100A and / or 100E via capillary action, depending on the porosity percentage of the carbon-based particles 100A and / or 100D. The total amount of S that can be infused into the interconnected microstructures 107E and / or deposited on the exposed surface areas of the carbon-based particles 100A and / or 100D and other similar structures can also be determined based on their porosity percentage, wherein the 3D fragmented structure provides larger pores such as pores 105E, each pore having a size 103E that can effectively accommodate and micron-limit S for the required period during electrochemical battery operation. There are instances where, under conditions where S is limited to defined percentages such as 0-5%, 0-10%, 0-30%, 0-40%, 0-50%, 0-60%, 0-70%, 0-80%, 0-90%, and / or 0-100%, the structure S is designed and grown to combine S to prevent any resulting polysulfide (PS) from migrating outside the pores 105E. Any one or more of these percentage ranges successfully demonstrates a delay in the migration of polysulfide outside the electrode structure. [ Implemented in ] [ Li ] [ Carbon support structure in air-filled secondary battery packs ]

[0220] Existing Li-air cathodes can only sustain 3-10 cycles, and therefore are not yet widely understood as providing a promising or reliable technology. In such cathodes, air itself acts as the cathode, thus a reliable and robust supply of air flowing through the cathode, such as through orifices, or other openings, is currently effectively excluded from practical applications in consumer-grade portable electronic devices such as smartphones.

[0221] The device could be manufactured using some form of air pumping mechanism, but air purification remains a problem, given that any amount of impurities present in the air can and will react with available Li in parasitic side reactions, ultimately reducing the overall specific capacity of the electrochemical cell. Furthermore, air provides only about 20.9% O2, and is therefore not as efficient as other alternative current advanced battery technologies.

[0222] Nevertheless, even given the challenges mentioned above, the examples provided above regarding the implementation of carbon-based particles 100A, 100D, and / or any variations thereof in carbon scaffolds 300B and / or lithium-lithiated carbon scaffolds 400A can be assembled for operation in 3D-printed battery packs. Notably, measures can be taken to protect against unwanted and / or sudden collapse of the porous structure, such as by tuning to achieve the desired structural reinforcement in specific targeted areas of the open porous scaffold 102A, thus avoiding the blockage of pathways defined therein. In the example, the carbon scaffold 300B can be decorated with numerous metal oxides to achieve this reinforcement, which can also control or otherwise actively contribute to the mechanical tunneling of the structure itself once lithium reacts with air to spontaneously form a solid from that state. Conventional methods, such as those involving the special preparation of the disclosed carbon-based particles 100A and / or their analogues and the Li-air cathode, can otherwise involve the reaction of Li ions with gaseous carbon to form an expanded solid. Depending on the location of this amplification, overall carbon-based mesoporous scaffold structures, such as the carbon scaffold 300B, can be mechanically degraded. [ Preparation of carbon-based particles for lithiation ]

[0223] To enable alternative non-Li or lithiated carbon-based scaffolded cathodes on current lithium oxide compound cathodes, such as alternative non-Li or lithiated carbon-based scaffolded cathodes that confine sulfur, oxygen, and vanadium oxide, and to accommodate the reduced coulombic efficiency resulting from first-charge lithium loss in current Li-ion batteries, scalable pre-lithiation methods for carbon-based structures intended for implementation in electrochemical battery electrodes are needed. Therefore, various experimental attempts have been made on carbon-based particles 100A, 100D, and / or any derivative structures based thereon, including carbon scaffolds 300B, such as ball milling, post-thermal annealing, and electrochemical reduction starting from an additional electrode. These results have been used for pre-lithiation, such as chemically preparing carbon-based structures to physically and / or chemically react with lithium and / or physically and / or chemically confine lithium, while meeting the challenges of uniformity, lithium reactivity, cost, and scalability.

[0224] Nevertheless, as substantially discussed earlier, by fine-tuning reactor process parameters, carbon-based particles 100A, 100D and / or carbon support 300B can be synthesized and / or manufactured by layer-by-layer deposition to serve as a carbon-based host structure with engineered surface chemical reactions, such as nitrogen and oxygen doping to promote the rapid decomposition of oxides involved in disproportionation.

[0225] During thermal activation, which may include one or more spark formations, Li metal can spontaneously, non-passively, driven by capillary forces without a pressure gradient, wet to produce controlled pre-lithiated carbon structures or particle building blocks. These pre-lithiated particle building blocks can then be synthesized into an integrated composite film with hierarchical conductivity, ranging from high conductivity at the plane after contact with the current collector, as shown by the intermediate layer 406A, to an insulating ion-conducting layer at the electrolyte / electrode plane. Surface chemistry properties associated with the non-reactive wetting of Li metal can be tuned by optimizing the thermal reduction of oxides (e.g., exothermic) using analytical techniques such as thermogravimetric analysis (TGA) or differential scanning calorimetry (DSC).

[0226] To address scalability issues related to transitioning from low-volume laboratory testing and sample production environments to large-volume, large-scale factories capable of simultaneously fulfilling multiple customer orders, the pre-lithiation method described above is similar to other liquid melt wetting methods such as hard soldering and is easily adaptable to continuous roll-to-roll (R2R) formats.

[0227] In the case of the torch method, under controlled thermal drying environment, thin film Li-coated foils, which may include tantalum (Ta) or copper (Cu) in some compositions, can be loaded onto a heated burnishing spool to contact carbon-based particles 100A or carbon films. Thermal retention, time, gradient, and applied pressure, such as immersion, can be adjusted and controlled to promote both: (1) activation; and (2) wetting process steps. [ Initiating carbon scaffold lithiation ] [ ]

[0228] Before extending the Li metal infusion method to carbon-based structures and / or aggregated particles, efforts were made to evaluate the following two scenarios: ● Growth of microwave graphene sheets with extended D-spacing, which allows Li intercalation between individual graphene sheets to occur at a much higher efficiency or faster rate than that occurring in typical commercially available graphene sheets; and growth of FLG in a manner that successfully and reproducibly achieves this higher D-spacing; and ● Using wet liquid Li metal front surface delivered to the layered pores 101A and / or connected microstructures 107E defined by open porous supports 102A of carbon-based particles 100A and / or 100D, wherein the attraction of Li metal to the exposed carbon-based surface to wet is the same as that to other exposed carbon-based surfaces that are functionalized in other ways.

[0229] The thermal reactor disclosed in this invention can perform post-processing to produce highly organized and structured carbon, which operates in conjunction with the wetting of molten Li metal and / or other species, such as aluminum, into silicon carbide sintered materials, and promotes the frontal wetting of molten (Li) metal by hammering the particle surface without additional pressure from an external source. These efforts allow for continuous wetting instead of using capillary pressure to push the metal into the open porous support 102A of carbon-dominant particles 100A and / or 100D.

[0230] Figure 4A shows a lithium-carbon scaffold synthesized and deposited in layers 406A to 412A, formed from several interconnected carbon-based particles 402A, similar in form and function to carbon-based particles 100A and / or 100E, at varying concentration levels from highest to lowest. All layers 406A to 412A were assembled and impregnated with a solution of molten Li metal and / or Li ions in liquid or liquid phase via a non-reactive capillary perfusion method to sandwich Li ions between the graphene sheet pairs of graphene sheet 101B. An illustrative D-spacing of approximately 1 Å to 3 Å can be targeted during the synthesis of graphene sheet 101B to retain more Li ions between the alternating graphene sheets than conventional graphene sheet stacks.

[0231] The voids 416A between adjacent and / or contacting carbon-based particles 402A, representing empty regions or spaces, can be partially defined by a lithium-carbon support 400A positioned away from the current collector 420A and facing the liquid electrolyte layer and passivation layer 418A. Passivation means that the material becomes passive, i.e., less affected by future usage environment or corrosion. Alternatively, a Li ion-conducting insulating or hierarchical intermediate phase layer can be deposited on layer 412A, for example, at the same location as passivation layer 418A, facing the electrolyte 414A, to minimize side reactions with free and / or physically and / or chemically unbonded ionic Li.

[0232] If any of the capped Li provided by molten Li metal can flow in liquid form into the voids 416A defined by carbon-dominant particles 402A prior to deposition or placement, it can help form an electrochemical gradient proportional to the concentration level of carbon-dominant particles 402A in each of the film layers 406A-412A.

[0233] The repeated or cyclic use of Li-ion electrodes (such as anodes or cathodes) in secondary battery packs can lead to problems caused by the use of molten Li metal, such as volume expansion during redeposition in electroplating operations, which refer to the use of current to reduce the amount of dissolved metal cations that form a thin, coherent metallic coating on the electrode. The term can also be used for the electrochemical oxidation of anions onto a solid substrate, such as the formation of silver chloride on silver wire used to manufacture silver / silver chloride electrodes.

[0234] The method used in the electroplating associated with the wetting of Li-ion solution into the lithium-carbon substrate 400A is called electrodeposition, also known as electrophoretic deposition (EPD), and is similar to that of a concentration cell with reverse action. Li-ion electroplating as described above can result in a volume expansion of approximately 400% or more of the lithium-carbon substrate 400A. From a stability point of view, such expansion is not micromechanically desirable and causes degradation of many inactive regions, which are inactive or non-chemically and / or electrically activated regions, thus ultimately preventing the development of longer lifespans beyond those of such Li-ion battery packs. Generally, a large amount of Li-ion material is required, meaning reduction to a smooth and uniform surface to thus promote uniform deposition of Li-ions. Removal within a smooth and flat interface is also smooth.

[0235] In practice, Li, when impregnated within the carbon support 400A, can tend to form undesirable dendritic crystals, defined as crystals developing in a typically multi-branched, tree-like form. These Li-ion dendritic crystals, also in the form of needle-like Li-ion dendritic crystals (needle-like describing the inertial state of a crystal composed of elongated needle-like crystal deposits), grow away from the surface on which Li-ions are impregnated, such as on and / or between individual graphene sheets 101B. In some cases, under sufficient charge-discharge cycles of the battery pack, dendritic protrusions or bumps can grow from the anode of the lithium-based carbon support 400A within the electrolytic cell to the cathode positioned opposite the carbon-based support, creating a short circuit or short path, describing a low-resistance connection between the two conductors supplying power to the circuit. This can generate excessive voltage cross-current and cause excessive current flow in the power source. The current is too short-circuited, resulting in a short circuit.

[0236] The capillary Li-ion infusion technology into a lithiated carbon scaffold 400A addresses many of the described problems. However, a persistent problem in Li-ion battery packs is that conventional cathodes offer only a limited amount of specific capacity or specific energy. Similarly, reduced specific capacity and specific energy density have been observed on the anode side. Therefore, even to a relatively satisfactory degree, Li-ion battery packs, when incorporated with any or more of the carbon-based materials disclosed in this invention (such as the lithiated carbon-based scaffold 400A), offer greater advancements in terms of energy storage capacity and current delivery compared to Li-metal hydride, lead-acid, or Ni-Cad battery packs, in terms of protection against or prevention of undesirable lithium-based dendrite formation, and even in terms of energy storage and delivery, approaching the theoretical capacity of pure Li metal with a specific capacity of approximately 3,800 mAh / g.

[0237] Other approaches have been explored, including the development of solid-state battery packs, which do not involve the liquid phase at all. However, due to the use of an oxidizing electrolyte to achieve and stabilize lithium contact, attention has returned to Li metal. Alternatives to Li metal, including Si, Sn, and various other alloys, are also being explored. However, even after eliminating Li metal, a Li ion source may still be required.

[0238] Alternatives to lithium materials in the electrode structure of Li-ion battery packs can produce the following energy densities: oxides provide 260 mAh / g; and sulfur (S) provides 650 mAh / g. Due to its relatively high energy density, sulfur (S) needs to be confined in battery pack electrode applications to prevent it from dissolving in the surrounding electrolyte. To achieve this, sulfur needs to be micron-confined, as previously described regarding the pores 105E of the interconnected microstructure 107E (shown in Figure 1E) of the open porous scaffold 102A. Confined (or micron-confined) liquids refer to liquids that are geometrically confined at the nanoscale, such that most molecules are close enough to the interface to sense a difference from standard conditions. Typical examples are liquids in porous media or liquids in fused shells.

[0239] Restriction and / or micron-level confinement refers to the regular prevention of crystallization within a microscale region, allowing the liquid to be supercooled below its homogeneous nucleation temperature, even if this is impossible in a bulk state. Therefore, given the various challenges presented above and others not discussed here, various improvements to conventional graphene-based anodes can be achieved by alternatively utilizing few-layer graphene (FLG) materials and / or structures (defined as the growth, deposition, or otherwise organization of graphene with fewer than 15 layers in a stacked architecture, wherein Li ions are sandwiched between the stacked supports at defined intervals and / or concentration levels). Carbon-based particles 100A, 100D, and / or similar materials can thus be prepared.

[0240] Thus, from graphite to FLG, the specific capacity of carbon-based structures with interspersed Li can be increased from approximately 380 mAh / g to over 1,000 mAh / g. The disclosed material can replace graphite with FLG to allow for a higher active surface area and increase the spacing between individual graphene layers, enabling the wetting of up to 2 to 3 Li ions, while other areas typically show only 1 Li ion. As shown in Figure 1I, various graphite or graphene layer planes can be controlled according to the spacing to achieve various fits of Li ions between adjacent graphite or graphene layer planes.

[0241] In graphene, the hexagonal carbon structures within each graphene sheet can remain positioned on top of each other; this is called the AA encapsulation sequence rather than the AB encapsulation sequence. An illustrative carbon encapsulation sequence is shown in the chemical structure diagram shown in Figure 1G, where Li ions can fit into the voids defined by carbon atoms arranged and bonded in a hexagonal lattice structure. Specifically, envision an assembly of graphene sheets and / or few-layer graphene (FLG), where individual graphene layers can be directly stacked on top of each other to obtain asymmetrical, disproportionate, and / or otherwise irregular stacks, as shown in stage 3 of Figure 1H, which further allows for the addition of intercalary Li ions between each graphene layer of the FLG structure.

[0242] Inserting Li ions into layered graphene structures from top to bottom or bottom to top under conventional conditions and circumstances can be extremely difficult in practice. Li ions are more readily inserted between individual graphene layers separated by definable distances. Therefore, the key lies in managing and tuning how much of the edge region is available. In this respect, any of the carbon-based structures disclosed herein can be tuned in this way. Furthermore, carbon in graphene is conductive, thus this characteristic provides a dual function by: (1) providing structural definition for FLG scaffold electrode structures, such as carbon scaffold 300B and / or lithium-lithiated carbon scaffold 400A; and (2) providing conductive pathways within them.

[0243] The fabrication techniques used to manufacture any or more of the carbon-based structures disclosed herein demonstrate the need to adjust the edge lengths of individual graphene layers relative to their flat surfaces; furthermore, adjusting the spacing between individual graphene stacks is possible. Graphene (in its two-dimensional structure) must provide significantly more surface area into which Li ions can be inserted. Therefore, various applications of graphene sheets according to the subject matter disclosed herein can provide a natural evolution toward enhanced energy storage density.

[0244] Individual graphene sheets are held in place as part of the plasma growth process. As previously described from FLG and / or combinations of particles (such as carbon-based particles 100A, 100D, 402A and / or their analogues), carbon-based gumball-like structures are self-assembling in a defined long-range order, defined as in which the solid carbon material exhibits a crystalline phase structure. Once the positions of carbon atoms and their neighbors are defined, the position of each carbon atom can be precisely defined throughout the crystalline phase structure to allow smaller structures to aggregate and form essentially spherical structures.

[0245] The size dimension of such spherical structures describing individual carbon-dominant particles 100A and / or their similarities may be approximately 100 nm at their respective widest points. The larger cohesive particles forming the carbon lattice structure 1800 shown in Figure 18 may consist of multiple spherical structures with diameters on the order of 20 to 30 micrometers, and provide structural definition for one or more of the films 406A to 412A shown in Figure 4A.

[0246] In contrast, traditional battery electrode fabrication methods typically employ known deposition techniques (such as chemical vapor deposition (CVD) or other manufacturing techniques, nanotubes, etc.) to grow structures away from a defined fixed substrate or surface, and therefore do not involve the ongoing fusion of carbon-dominant particles in the essentially atmospheric vapor stream of the carbon-containing gaseous material disclosed herein. Such known assembly processes and procedures can often be extremely labor-intensive and may allow for the growth of structures with limited thickness (200 to 300 micrometers).

[0247] The densification of graphene on a pristine spherical carbon scaffold, such as multiple FLGs (fiber-forming polymers) including carbon-based particles 100A, carbon scaffolds 300B, lithium-based carbon scaffolds 400A, and / or similar components, can also increase energy density and capacity. Such densification in target areas of the carbon scaffold can be performed or otherwise achieved after the formation of larger cohesive particles comprising multiple carbon-based particles 100A. Generally, Li ions can be electroplated onto the electrode prior to reduction, thus allowing Li ions to transition from an ionic to a metallic state, depending on the battery pack chemistry. Furthermore, in one embodiment, similar to electroplating, graphene can be grown in a stacked manner on other materials such as plastics and tuned to obtain a desired bright and / or smooth surface finish. Such electroplating processes are reversible and may include separate but related plating and stripping processes intended to place Li ions and / or atoms downwards for their subsequent removal.

[0248] In the continuous cycling of secondary Li-ion battery packs involving multiple charge-discharge-recharge cycles, the carbon-based structure growth and / or the surface construction eventually become rough and thus sensitive to or prevent the growth of unwanted dendrites. In contrast, as discussed above, the technology for producing carbon-based particles 100A and / or similar materials achieves higher specific capacity values ​​by using substantially impurity-free Li metal along with a carbon-based graphene structure, thereby substantially preventing such dendrite growth.

[0249] The use of graphene sheets allows for a relatively large exposed surface area, which can be used for plating or sandwich operations for wetting of non-reactive capillary infusion involving Li ions. Therefore, any tendency to migrate to a single point is eliminated; and essentially, due to the higher surface area to volume ratio of graphene compared to other known carbon-based materials such as graphite, the plating and stripping mechanisms can be altered. The introduction of Li ions can be at least partially dependent on liquid Li; however, given the readily chemically reactive nature of Li with surrounding and / or surrounding elements, it must be kept away from water-based moisture and oxygen. Similarly, the introduction of impurities has detrimental effects. Regarding the revealed carbon-based structures, metal-matrix complexes (regarding Li metallization bonding or otherwise forming metal-matrix complexes with C) have been studied, thus providing additional options for finely tunable and manageable reactivity at the exposed surface.

[0250] Li in contact with C can lead to the need to suppress and / or control the free energy of Li at the contact surface to avoid undesirable reactivity associated with spontaneous Li wetting of carbon-based particles 100A and / or their likenesses. Traditionally, due to the chemical properties of the electrolyte, Li in the liquid phase typically forms carbonates and other formations. However, the present invention addresses the generation of a relatively stable solid electrolyte interface (SEI) prior to the introduction of a liquid electrolyte.

[0251] Furthermore, various methods and / or processes are available to influence the Li ion interface region. For example, preparing the surface of liquid Li by alloying with Si and other elements reduces reactivity and promotes the overall Li ion wetting of larger cohesive particles, each comprising multiple carbon-dominant particles 100Å. In one instance, less than 1.5% of Li was observed to preferentially migrate to the exposed surface of the electrolyte. [ Increased specific capacity in 3D ] [ Hierarchical graphene ] [ ]

[0252] The commercial applications of graphite carbon materials for anodic active materials and fine carbon black materials for electrical conduction are justified by their relatively low cost, excellent structural integrity for inserting and extracting Li+ ions, safety independent of Li dendritic crystal formation, and the formation of protective passivation layers for many electrolytes, such as those associated with the formation or accumulation of solid electrolyte interphase (SEI).

[0253] However, the low specific capacity of graphite with the stoichiometric formula LiC6 at 372 mAh / g is a key limitation and could therefore potentially hinder the development of large-scale energy storage systems requiring high energy and power density. By designing and applying three-dimensional (3D) graphene with Li and / or S sandwiched between compounds as disclosed herein by means of any one or more of the foregoing figures, a larger loading of active anode material can be achieved while simultaneously promoting Li ion diffusion. Furthermore, 3D nanocarbon frameworks, such as those defined by open porous scaffold 102A and / or their analogues, can provide: conductive pathways; and structural buffers for higher-capacity non-carbon nanomaterials, resulting in enhanced Li ion storage capacity. Both (1) and (2) enhance Li ion storage capacity (>1,000 mAh / g) and improve cycling (stability) performance using these 3D structures. [ anode ] [ - ] [ Electrolyte interface ] [ ]

[0254] The graphene and carbon derivative structures disclosed in this invention can be incorporated into anodes to enhance the performance of demanding Li-ion and LiS battery packs, such as anodes formed substantially from stacked graphene with Li sandwiched within them. Alternatively or additionally, conventional solid Li metal foil anodes can be used with carbon-based cathodes characterized by interconnected microstructures 107E (shown in Figure 1E) in LiS battery pack systems. Nevertheless, problems related to undesirable chemical side reactions associated with the formation of the solid-electrolyte interface (SEI) may be observed at the Li anode in LiS batteries. In addition to electroplating and electrolytically dissolving Li in the core redox chemistry of the battery to release Li+ cations into the electrolyte, the typical anode construction also provides a source of reducing agent species, while excess Li acts as a lightweight current collector and helps to combat poor coulombic efficiency. The resulting anode degradation significantly contributes to reduced cycle life and limits anode applications. If the energy density of a LiS battery is set at 400 Wh / kg, the thickness of the Li metal is estimated to be 1-200 µm, more preferably 20-50 µm (corresponding to 5-10 mAh / cm). In most cases, commercial foils are 70-130 µm thick.

[0255] Li is highly reactive and lightweight, making it an ideal candidate for battery technology designed for high gravitational energy density. However, this reactivity causes Li to react with many chemical species it comes into contact with, forming one or more undesirable byproducts. These undesirable byproducts (and their corresponding products) typically do not generate new energy and may lead to irreversible loss of Li and other electrolyte components. Electrolyte depletion, battery drying, and / or Li loss accelerate capacity decay. [ SEI ] [ form ] [ ]

[0256] The chemical reaction between Li and electrolyte components forms an electrolyte interphase (SEI) on the Li anode surface. The Li anode then slows down the reaction between the electrolyte components and the anode, reducing degradation and thus improving cycle life. The SEI covers the anode surface, and first-order electrochemical reactions occur through the SEI layer. The properties of the SEI layer affect reaction kinetics and can reduce battery voltage due to increased internal resistance. Regardless of these factors, the SEI layer and its characteristics are crucial to anode performance and are a focus of anode-related materials research in Li₂S batteries. Although materials research in the electrolyte field focuses on selecting stable solvent systems or reactive additives that promote favorable SEI composition, the solvent is the primary source of organic Li salts in the SEI film.

[0257] Disordered structure promotes ionic conductivity, while the thickness of the SEI layer increases internal resistance. Thin film growth ceases when electron transfer is blocked, typically in the tens of angstroms. The compact hierarchical layer model is commonly used to describe the SEI on Li anodes. This model considers that the surface film on the anode consists of a porous mesophase and a compact mesophase, which is composed of sublayers. The porous outer layer closest to the solution is heterogeneous because the reduction in solution species prevents this from occurring across the entire film-solution interface, but rather at points where electrons can tunnel to surface defects or holes. The composition of the SEI gradually changes as it moves from solution / SEI to SEI / Li. Near the Li anode surface, lower oxidation states are observed, and the SEI can become more compact.

[0258] The formation of the SEI (Sediment-Insulated Layer) offers both benefits and challenges depending on specific chemical and physical properties. For example, rough and heterogeneous SEIs, such as those of disordered mosaic types derived from soaking, promote better growth through cracks and in regions where the SEI is thinner. Intact and smooth SEIs with largely eliminated local defects effectively suppress intrinsic and induced Li dendritic growth, which is desirable for the performance of Li-ion and LiS battery packs. Ideally, the SEI should be chemically stable, Li-ion conductive, compact, homogeneous, and mechanically rigid and flexible to accommodate the volume changes associated with PS shuttles encountered in typical LiS system cycling. [ Anode morphology ] [ ]

[0259] Besides the formation of the SEI during charging and discharging, Li stripping and electroplating also cause morphological changes over time. Natural defects in the soft Li metal anode can act as nucleation sites for Li dendrites. The uneven stripping and electroplating of Li over time increases the surface area of ​​the Li anode and correspondingly introduces porosity, which manifests as multiple interstitial pore volumes. This phenomenon is called "three-dimensional (3D) moss growth." While this process increases the reactive anodic surface area for electrochemistry, it also promotes the continuous breakage and remodeling of the SEI. This cycling process depletes the electrolyte components in the battery that form the reactive SEI over time. Furthermore, irreversible side reactions during cycling may consume the Li anode active material and impair the Li anode's ability to act as a current collector.

[0260] Moss-like growth is a 3D omnidirectional moss or shrub-like growth. 1D growth forms 3D growth through broadening and branching during filamentous growth. This omnidirectional growth can be explained by the "raisin bread" expansion model, where there is no preferred orientation and the distance between the raisins increases as the bread roll expands. The growth model does not have a growth center, but the movement of Li dendritic crystals can be restricted by the available structural supports, where the Li metal anode can act as a substrate on which any growing moss is attached. Since Li atoms can be inserted over the entire Li anode structure, growth may not necessarily occur at the exposed ends of the Li anode surface, nor at distributed growth points or regions. The growth and dissolution of Li moss-like structures are nonlinear dynamic processes, where the movement associated with the formation of Li dendritic crystal structures appears random and is not governed by any direction of the electric field in the constructing electrolyte. During the dissolution process, most of any Li dendrites formed can become electrically disconnected. This can still occur even if the Li dendrites remain connected to their original positions at the SEI layer, as the Li dendrites extend from the SEI layer. This is because the electrical contact sites are replaced by the insulating and passivating SEI layer.

[0261] The Li anode surface exposed to the surrounding electrolyte must generally be relatively smooth to ensure the formation of a uniform SEI layer. The effect of controlling the initial Li surface roughness depends on the nature of the natural SEI. Simple roll pressing can be used to form an artificial SEI with controlled surface finishing, which can help reduce overpotentials during plating and deplating in symmetrical cells. [ Barrier layer on the anode ] [ ]

[0262] Excess Li can be used as a current collector in solid Li foil anodes, such as in Li₂S systems, to combat low coulombic efficiency. In Li-ion batteries using Li metal, the formation of Li dendrites (also interchangeably referred to as dendritic structures) poses safety concerns due to the potential for internal short circuits. These safety issues include rapid self-discharge of the affected battery, where the dendrites extend from the anode to the cathode, creating pathways that allow electrical or ionic charges to travel rapidly, rather than the intended pathways for powering the load. The term dendrites encompasses a range of structures including needle-like, snowflake-like, tree-like, shrub-like, whisker-like, and moss-like structures. In most Li₂S systems, only moss-like growth has been observed in practice, and internal short circuits attributable to dendrite growth have not been reported as practical problems. However, these potential problems do present concerns for demanding future applications. Therefore, methods such as at least partially encapsulating the Li anode to prevent unwanted Li dendrites from growing from the barrier layer or capping layer of the layer have been advanced to address the growth of Li dendrites, which has the potential to be used as a penetrating spacer for Li-ion technology. Some of these methods can be applied to LiS technology to combat shuttle effects and other degradation processes.

[0263] Most methods for preventing dendritic crystal formation in rechargeable Li batteries have focused on SEI stability and uniformity using electrolyte additives. As previously discussed, these methods often have short lifespans due to the thermodynamic instability of Li metal in organic solvents. Nevertheless, their scalability and ease of commercialization make them attractive.

[0264] An alternative approach involves forming a dissimilar mechanical barrier on the Li foil anode, which is configured to prevent the growth of Li dendritic crystals that begin from the Li anode surface exposed to the electrolyte. Examples include polymer coatings or ceramics with high shear moduli to reduce damage to and repair of the protective layer, which would further deplete the reactive components in the electrolyte. Reel-to-reel coating techniques for Li coatings can be developed; these techniques are used, for example, in the semiconductor industry.

[0265] The barrier relies on forming a strong mechanical layer while attempting to minimize its impact on first-order electrochemical reactions. If the barrier layer blocks electrochemical activity, this method can easily generate high internal resistance within the battery. The polymer layer can be cast onto Li and dried; the advantage lies in the flexibility of the polymer, which makes it stable against volume changes during cycling. The challenge is finding a conductive polymer or achieving a thin coating that does not significantly increase the internal resistance of the battery. The polymer layer needs to be insoluble in the electrolyte and stable in the presence of polysulfides, nucleophiles, and free radicals.

[0266] SEIs formed by organic solvents are typically brittle and therefore cannot withstand mechanical deformation, leading to crack formation. These cracks increase Li ion flux and result in dendritic crystal formation and the formation of new SEIs. Cyclic fracture and repair of the SEI consume Li and electrolyte, leading to battery pack failure. Volume changes are a major problem causing most methods for forming stable SEIs to fail. A flexible, intelligent SEI layer has been developed using an in-situ reaction between Li and polyacrylic acid (Li PAA). Li PAA exhibits excellent uniform adhesion and sufficient flexibility to accommodate Li deformation. [ Mechanically reinforced mixed artificial solids ] [ - ] [ Electrolyte interface ] [ (A ] [ - ] [ SEI) ] [ ]

[0267] Based on attempts and some successful methods in developing effective barrier layers or capping layers suitable for limiting Li dendritic growth starting from the Li anode, the following solution is proposed: Integrating one or more of the carbon-containing aggregates of self-nucleating graphene sheets, such as those discussed in the diagrams, with a usable polymer to generate a barrier layer. The exposed carbon can act as a type of mechanical strength enhancer for solid Li metal foil anodes or carbon-based anodes with Li sandwiched in between, effectively suppressing the formation of lithium dendrites on exposed lithium metal at the anode and enabling stable Li-S battery packs with long lifespans. These efforts can be used independently of or in combination with one or more conventional Li dendritic growth reduction techniques, including: • Using an electrolyte or an electrolyte containing additives can help develop a stable and uniform SEI layer inside the Li anode; • An artificial SEI (A-SEI) layer is externally coated onto the Li anode before battery assembly; and • Carbon-Li composite materials are prepared by infusing Li into a given carbon-based 3D structural material.

[0268] The technology disclosed in this invention attempts to incorporate multiple active components with mechanical strength enhancers, such as polymers incorporated with the disclosed carbon, to fabricate A-SEI films to produce ultrastable Li anodes suitable for implementation in Li-S battery pack systems. The proposed A-SEI is ideal in many forms and provides at least the following characteristics: • Chemical and electrochemical stability of Li metal, electrolyte, and other battery components in typical Li-ion or Li₂S operating conditions, such as contact conditions, within ranges of temperature, pressure, current, and voltage. • The mechanical strength is designed to suppress the formation of Li dendritic crystals starting from the Li anode; • Adaptability or elasticity to the volume changes of polysulfide (PS) shuttles encountered during charge-discharge operational cycles in LiS battery pack systems; • Conformity and uniformity of any and all surfaces of an anode, such as a solid Li metal foil anode or a carbon-based anode with Li sandwiched in between, that substantially surrounds and adheres to the surrounding electrolyte; and • High ionic conductivity for the required Li+ ion transport throughout the battery, resulting in enhanced power delivery and battery life.

[0269] Alternatively or additionally, to incorporate the polymer into the carbon, inorganic chemicals may be added to the proposed barrier layer. These inorganic chemicals may include, but are not limited to, any one or more of the following: alumina (Al₂O₃), lithium fluoride (LiF), polysulfides (such as Li₂S₆), phosphorus pentasulfide (P₂S₅), lithium phosphate (Li₃PO₄), lithium nitride (Li₃N), silicon dioxide (SiO₂), molybdenum disulfide (MoS₂), and Li₂S₃. Any one or more of these may provide suitable materials for forming a passivation layer due to their relatively high chemical stability (e.g., becoming "passive," i.e., less susceptible to environmental impact or corrosion from future applications). However, if the barrier layer formed by at least some of these inorganic chemicals is excessively thick, these inorganic chemicals may, for example, potentially hinder the required and necessary Li ion (Li⁺) transport from the anode to the cathode. Polymers can be added to mixtures comprising such inorganic chemicals and co-added to any or more of the carbon derivatives disclosed in this invention to form a barrier layer. These polymers may include crosslinked variants of: polydimethylsiloxane (PDMS), polystyrene (PS), bis(1-(methacryloxy)ethyl) phosphate, succinate, maleate, phthalate, or phosphate esters, with 2-hydroxyethyl methacrylate as a primary binder, glyceryl dimethacrylate maleate, polyethylene glycol (PEO), poly(3,4-ethylenedioxythiophene) (PEDOT), styrene-butadiene rubber (SBR), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), and polyvinylidene fluoride (PVDF). These polymers are elastic and self-healing, and therefore can adapt to substantial volume changes during battery pack cycling. However, its lack of rigidity may be insufficient to suppress dendritic crystal formation over extended periods of use.

[0270] To best combine the beneficial characteristics of inorganic A-SEI and / or polymer-based A-SEI, while further enhancing the mechanical strength and / or integrity of the barrier layer prepared as a thin film, a hybrid A-SEI is disclosed. The hybrid A-SEI layer can be prepared to include one or more of the following: • Active inorganic components, such as any of the previously presented active inorganic components and / or including LiF, LiN3, Li-metal alloys, Li-Si, Li3PO4, LiI, Li3PS4; higher crosslinkable analogs of Zn, Sn, Sr, Ln, Al or Mo and / or their analogs; and • Polymer-based and mechanically reinforcing agents, including and containing polymer binders (such as SBR) to provide structural reinforcement and flexibility of the revealed carbon-based structure; etc.

[0271] Manufacturing techniques suitable for producing hybrid A-SEI layers may include any one or more of the following: drop casting, doctor blade coating, spraying, UV curing, and thermosetting.

[0272] Figure 4B shows a simplified schematic diagram of an A-SEI-protected anode 4B00, which can be used as an example of the carbon-based electrode structure shown in Figure 3. In some other embodiments, and unlike the electrode shown in Figure 3, the electrode shown here in Figure 4B can be prepared as a carbon-free solid Li metal foil anode 4B12 supported by a copper foil current collector 4B14. According to some embodiments, the solid Li metal foil anode 4B12 has an exemplary mixed artificial solid-electrolyte mesophase (A-SEI) layer deposited thereon, the mixed A-SEI here consisting of two active component layers, a first active component layer 4B04 deposited on a second active component layer 4B06, the two layers substantially encapsulating the solid Li metal foil anode 4B12. Either of the active component layers may include or be formed from the present active component (or other active component) and any combination of a polymer-based and mechanically reinforcing agent. The first active component layer 4B04 can primarily function as a solid barrier layer or capping layer, preventing direct contact between the Li metal contained within the solid Li metal foil anode 4B12 and the electrolyte 4B02 surrounding the solid Li metal foil anode 4B12. This confirmation that the first active component layer 4B04, prepared as a barrier layer, can prevent the formation of unstable SEI, electrolyte decomposition, and drying can help maintain high efficiency throughout the lifespan of the Li-S battery pack and allow for a relatively low electrolyte-to-sulfur (E / S) ratio (e.g., approximately 4.2 µL / mg).

[0273] To supplement the preparation of the first active component layer 4B04 as a solid barrier layer or capping layer, the second active component layer 4B06 can be prepared primarily to enable uniform Li deposition on the surface of the solid Li metal foil anode 4B12 exposed to the electrolyte 4B02, such as through pores and / or void regions formed in any one or more of the first active component layer 4B04 and the second active component layer 4B06, thereby correspondingly suppressing the formation of Li dendritic crystals extending from the solid Li metal foil anode 4B12. The mechanical strength enhancer, including any one or more of the exposed carbon-based aggregates such as a plurality of graphene sheets substantially orthogonally fused together, may include a first compound 4B08 and an optional second compound 4B10 displaced relative to the first compound 4B08. Mechanical strength enhancers comprising and referencing first formulation 4B08 and second formulation 4B10 respectively can be formulated to at least partially assist in retaining the A-SEI in the desired location, position, or configuration necessary to extend battery pack life. Furthermore, first formulation 4B08 and second formulation 4B10 can be prepared together to increase the strength of the A-SEI (such as the first module layer 4B04 and the second module layer 4B06), as reflected in the Young's modulus (> 6 GPa) of the mixed A-SEI, thus preventing the growth of Li dendritic crystals.

[0274] Figure 4C shows an example of the anode shown in Figure 4B, prepared according to some embodiments, having an anode formed from the multilayer carbon-based support structure shown in Figure 3. The same schematic symbols in Figure 4B refer to the same components in Figure 4B, the difference being that the solid Li foil anode 4B12 is replaced by the porous carbon-based support structure first shown and described in Figures 3 and 4A. This structure can be Li-wetted to provide many of the anode capabilities or characteristics of the solid Li foil anode 4B12 for providing Li ions (Li+) suitable for electrochemical migration required for proper Li-ion and / or LiS battery cycling operation. Given that the Li present within the carbon-based support structure shown in Figure 4C can theoretically also form dendritic structures, any or more of the disclosed components related to mixed A-SEI can also be reassembled to substantially encapsulate such carbon-based anodes and protect them from Li dendritic growth.

[0275] Figure 4D shows Table 4D00 of various exemplary conventional chemical adhesive materials or substances, also known as "adhesives," according to some embodiments. Any one or more of these materials or substances can be used to bind and / or bond together portions of the carbon-containing materials included in the mixed A-SEI layers shown in Figures 4B and 4C to enhance Li dendritic crystal formation protection. This paper discusses the needs for adhesive systems and mechanical strength additives for manufacturing mechanically reinforced mixed artificial SEIs and proposes solutions.

[0276] To prevent direct contact between Li metal and the host electrolyte, while enabling rapid Li+ transport, uniform Li deposition, and inhibiting dendritic crystal formation, a thin, uniform, and mechanically robust A-SEI layer is used to essentially encapsulate the Li anode surface. This requires a carefully designed formulation with the following characteristics: • Required chemical resistance to the electrolyte; • Required Li wetting and adhesion; Minimal shrinkage during drying or curing; • High packing density of mechanical strength enhancers in the A-SEI layer; and • High Li+ permeability of the encapsulation layer.

[0277] A flexible polymeric matrix A-SEI layer with good adhesion to Li surfaces is desirable, provided that the A-SEI layer is filled with the active components listed above and has a relatively high Young's modulus additive. Styrene-butadiene rubber (SBR) linear polymer is a well-known example of a usable flexible polymeric adhesive.

[0278] As experimentally demonstrated, SBR-based hybrid coatings significantly improve Li-S full-capacity cycle performance compared to cells with untreated Li anodes. However, when such linear polymers are used as binders for protective A-SEI layers, prolonged exposure to the electrolyte can lead to polymer dissolution over time and degradation of the corresponding protective layer.

[0279] The stability of the protective A-SEI layer coated onto the anode can be improved by incorporating one or more functional groups, such as -OH, -COOH, -NH2, or others, into the flexible polymeric structure to provide and promote the binding of ions to the metal surface, thereby increasing the adhesion of the A-SEI layer to the Li surface exposed to the electrolyte. For example, dicarboxylate-terminated polybutadiene and its copolymers, including poly(ethylene-co-acrylic acid) copolymers, can be used. These copolymers combine flexible polyethylene units and PAA units, exhibit strong affinity for Li, and are another good example of improved linear polymeric adhesives.

[0280] The optimal solution for achieving good chemical resistance to electrolytes may include forming a cross-linked polymeric network in which polymer chains are interconnected within a 3D network, thereby preventing the polymer chains from dissolving over time. Variations in cross-linking density and the composition of monomers and / or oligomeric blends will also allow for adjustments to the flexibility, good Li wetting and adhesion, and chemical resistance to electrolytes of the A-SEI coating. Various types of curing, including UV curing or thermosetting, can be performed on any or more of vinyl, acrylate, and methacrylate groups. Alternatively, epoxy-based curing may be used to form the cross-linked polymeric network.

[0281] For example, the following monofunctional and difunctional acrylate and methacrylate monomers, and combinations thereof, can be used to form UV-curable or thermocurable crosslinked polymeric networks: • Polybutadiene diacrylate, which can be used to impart improved flexibility to polymer blends; • Trimethylolpropane triacrylate, which can be used to impart crosslinking density control to polymer blends; and • Bis[2-(methacryloxy)ethyl] phosphate and its monofunctional analogues can be used to impart improved adhesion and lithium-binding capabilities to polymer blends.

[0282] These acrylate / methacrylate monomer-based blends, which have initially low viscosity, eliminate the need to add solvents to the protective A-SEI layer composition and allow the formation of A-SEI coatings with optimal flexibility, Li wetting and adhesion, chemical resistance to electrolytes, and Li+ permeability.

[0283] Co-existing methods can also be implemented, such as those involving the blending of linear polymer chains with one or more monomers and solvents to possess the desired functionalities, such as flexibility and adhesion (PAA, etc.) and lithium adhesion capabilities (PEO, etc.) provided by SBR, PBD, etc. Although using a single linear polymer chain as a binder can lead to its dissolution over time, the retention of these linear polymer chains in the crosslinked network prevents this dissolution. Furthermore, the long polymer chains can simultaneously minimize shrinkage of the cured film. And in contrast to (meth)acrylate systems that may require an inert environment to form a crosslinked network, similar concepts described above can be extended to epoxy-based systems that can be cured under ambient conditions.

[0284] Figure 4E shows an example 4E00 of zinc acrylate formation as a mechanical strength enhancing additive for the A-SEI shown in Figures 4B and 4C, according to some embodiments. Another important aspect of A-SEI formation, as previously described, is to shape the A-SEI into a defect-free film (e.g., free of pores or cracks) with high mechanical strength and providing good dispersibility of filler materials potentially used in A-SEI formation, as well as a high carbon particle packing density within the A-SEI. Both preferences can be achieved through the use of nanofillers. Nanoscale materials with high Young's modulus, such as nanofillers, are most advantageous as mechanical strength enhancers in the final A-SEI film.

[0285] For example, when ultrathin (< 2 µm) coatings are required, the morphology of nanofiller particles can become crucial. Compared to 3D nanofillers with a more spherical particle geometry, mechanical strength enhancers with a substantially 2D morphology (such as graphene, nanoclay, and mica) composed of nanosheets aligned under applied shear force can be more beneficial in imparting mechanical strength or other advantageous properties such as filler dispersibility to A-SEI.

[0286] Graphene, when organized into multiple graphene flakes fused together at substantially orthogonal angles, provides optimal mechanical strength enhancement due to its extremely high Young's modulus. Therefore, such high Young's modulus graphene materials can be used as strength-enhancing additives in A-SEI manufacturing. Unique graphene materials with substantially folded or wrinkled morphologies are particularly advantageous for this application, due to the specificity of the structure that combines highly crystalline and rigid graphene sp2-binding carbon domains with softer and more flexible "wrinkled" regions. This combination allows the graphene structure to adapt to the volume shrinkage of the A-SEI protective layer during manufacturing while simultaneously undergoing cross-linking to form polymers.

[0287] Graphene allotropes can be functionalized with epoxy, amine, thiol, carboxylic acid, (meth)acrylate, vinyl, and -Si-H groups, and one or more of these can be incorporated into dopants to further enhance film integrity. These functionalized graphenes can be covalently bonded to a matrix and cured via epoxy crosslinking with difunctional molecules containing double bonds at either end, free radical-initiated vinyl or (meth)acrylate crosslinking, or -Si-H group crosslinking, or a combination of these curing methods.

[0288] It is worth noting that the same material can provide multiple functions, such as one or more of the following: • Encapsulate the Li surface to act as a solid barrier to prevent direct contact between the Li metal and the electrolyte; • This enables uniform deposition of Li; and • By acting as a mechanical strength enhancer for A-SEI, dendritic crystal formation can be suppressed.

[0289] Examples of such materials are curable organic salts of Zn, Sn, In, and other metals. For instance, zinc acrylate deposited on a Li surface and cross-linked via UV or thermal methods produces a zinc polyacrylate layer, often referred to as a "dental adhesive" due to its high compressive strength at pH > 4.5 and good chemical resistance. Such cured films provide mechanical stability, while Zn²⁺ ions exchange with Li⁺ ions, enabling their transport through the film.

[0290] Figure 4F shows an exemplary formation path 4F00 of a metal polyacrylate suitable for protecting Li electrodes (such as anodes) according to some embodiments. This exemplary metal polyacrylate can be incorporated into any or more of the exemplary A-SEI formulations discussed earlier to obtain any or more of the discussed benefits such as reinforcement, thereby providing, for example, a self-sustaining, UV-cured semi-interpenetrating polymer network. [ Example ] [ ]

[0291] Figure 4G shows two photographs, 4G00 and 4G02, of an exemplary SnF2 / SBR coating on a control Hohsen Li anode with a Cu foil current collector (referred to as "Hohsen Li / Cu foil") according to some embodiments. The films were fabricated on the Hohsen Li / Cu foil using a doctor blade technique and baked at 60°C to accelerate the relevant chemical reactions and drying process. Yields of 0.3 mg and 2.3 µm SnF2 / SBR coatings were achieved. Photo 4G00 shows the SnF2 / SBR coating on the Hohsen Li / Cu foil after doctor blade coating; and photo 4G02 shows the SnF2 / SBR coating on the Hohsen Li / Cu foil after baking at 60°C for 20 hours.

[0292] Figure 4H00 shows the specific discharge capacity (in mAh / g) of an exemplary Li-S full-capacity cell with a Li anode treated with a LiF / Li-Sn alloy mixed A-SEI, a complete Hohsen Li control foil, and a cathode according to some embodiments. It shows a significant improvement in the performance of the SNF2 / SBR-Li mixed A-SEI combination of the Li-S full-capacity cell with LiF / Li-Sn alloy compared to the conventional Hohsen Li control.

[0293] Figure 4I shows an image 4I00 of an exemplary Si3N4 / SBR A-SEI coating on a comparative Hohsen Li / Cu foil according to some embodiments. The film was fabricated on the Hohsen Li / Cu foil by a doctor blade and baked at 60°C to accelerate the relevant chemical reactions and drying process. Yields of 0.3 mg and 1.6 µm Si3N4 / SBR coatings were achieved.

[0294] Figure 4J shows the specific discharge capacity (in mAh / g) of an exemplary Li-S full-capacity cell prepared according to some embodiments, with a Li anode treated with a LiN3 / Li-Si mixed A-SEI and a complete Hohsen Li control. The A-SEI-coated Li anode (referred to as at least Si3N4-Li) was tested in the Li-S full-capacity cell, and this Li anode showed significantly improved stability in early cycling.

[0295] Figure 4K shows an image 4K00 of an exemplary graphite fluoride / SBR A-SEI coating in a control Hohsen Li / Cu foil anode according to some embodiments. LiF and graphite are combined to form an A-SEI with an SBR polymer binder. The film is fabricated on Hohsen Li / Cu foil by a doctor blade and baked at 60°C to accelerate the reaction and drying process. A yield of less than 0.1 mg and approximately 1.3 µm graphite fluoride (GF) / SBR coating was achieved.

[0296] Figure 4L shows the specific discharge capacity (in mAh / g) of exemplary Li-S full-capacity cells prepared according to some embodiments, including Li anodes treated with a LiF / graphite hybrid A-SEI, a complete Hohsen Li control, and a cathode. The ASEI-coated anode (graphene-F, shown as GF-Li) was tested in the Li-S full-capacity cell, and this anode showed significantly improved stability in early cycling. [ Protective carbon interface layer for lithium metal anodic protection ]

[0297] Alternative or additional formulations of the A-SEI discussed exist to address various current limitations in Li-ion and LiS battery packs. Notable challenges can be attributed to the volume expansion observed in the cathode and the parasitic reactions observed in conventional (e.g., unprotected) solid Li foil anodes. Exemplary undesirable parasitic reactions that attempt to be prevented may include at least the following: [‧] Excessive SEI formation may lead to electrolyte depletion; [‧] Li dendrite formation caused by uneven current distribution leads to internal short circuits and inactive or "dead" Li; [‧] Lithium metal surface corrosion caused by reactants entering the electrolyte (i.e., polysulfide dissolution); and [‧] Suppressing or eliminating parasitic reactions associated with solid foil Li metal anodes can enable safe, cost-effective and high-energy-density battery packs that are useful in many end-use applications.

[0298] Battery pack manufacturers have encountered challenges related to parasitic side reactions observed in conventional battery packs with Li metal anodes, which contribute to the growth of potentially undesirable Li dendritic crystals. Attempts to address these parasitic side reactions may include, for example: [‧] The liquid electrolyte in the system is replaced by a solid electrolyte composed of various polymers, ceramics, or polymers and / or ceramics, such as lithium oxynitride, which tends to include highly ionicly conductive materials such as fluorides / sulfides in some combination form; [‧] A protective barrier layer or capping layer is directly introduced onto Li metal made of polymers and ceramics to protect the lithium metal itself from the influence of liquid electrolytes. Such protective layers include LiF, LiO, Li2S and other common lithium alloys or conductive materials; [‧] A patterned layer is formed on top of the solid Li metal foil anode to redistribute the electrochemical current in the electrode; [‧] Adding metallic Li alloying additives such as titanium (Ti), tin (Sn), or silicon (Si) has been used to help reduce parasitic reactions; and [‧ ] Add a mechanical stabilizing layer to prevent dendritic crystals from growing outwards onto the current collector.

[0299] Figure 4M is an exemplary schematic diagram of a protected electrode (anode) 4M00 comprising a carbon-containing layer (such as an electrically insulating sheet carbon layer 4M04) including carbon allotropes. In some instances, the electrically insulating sheet carbon layer 4M04 may be deposited on, around, or substantially encapsulate a naturally occurring solid-electrolyte interface (SEI) to prevent the unstable formation of the naturally occurring SEI. The carbon allotropes may be incorporated into the electrically insulating sheet carbon layer 4M04, which is shown laminated on top of a lithium-sheathed current collector foil 4M06 supporting a conventional solid Li metal foil anode 4M10. Alternatively, in some configurations, the lithium-sheathed current collector foil 4M06 may be configured as a functional anode. Alternatively, an electrically insulating sheet-like carbon layer 4M04 can be laminated onto a carbon-based anode comprising a graphite support or sheet with a few layers of Li-intercalated graphene. Any or more of these described assemblies are suitable for Li-ion or LiS battery packs. The electrically insulating sheet-like carbon layer 4M04 may have a thickness between approximately 0.1 µm and 50 µm and may include, with or without, one or more carbon allotropes (such as two different allotropes) or functionalized carbon (such as graphene oxide and carbon nano-onions, which define various interstitial pore volumes distributed throughout the electrically insulating sheet-like carbon layer 4M04, thereby allowing Li+ ions to be transported through it via path 4M14 and via the electrolyte 4M08, as necessary for proper battery operation). The carbon allotropes may have a particle size in the range of 0.01–10 μm. Adding an electrically insulating sheet-like carbon layer 4M04 acts as a "carbon shield" to protect the Li metal contained in the solid Li metal foil anode 4M10 (which in some configurations may alternatively be a carbon-supported anode comprising multiple graphene sheets with Li sandwiched between them) from interaction with the electrolyte. The electrically insulating sheet-like carbon layer 4M04 does this by providing the necessary surface for growth of the SEI (or alternatively, A-SEI such as the previously discussed A-SEI), preventing polysulfides (PS) from reaching the lithium metal anode, improving the uniformity of Li ion flux during normal battery pack operation charge-discharge cycles, adding mechanical benefits suitable for preventing Li dendritic growth extending from the anode to the cathode, and assisting in the regulation of volume expansion and contraction.

[0300] To suppress Li dendritic growth originating from the solid Li metal foil anode 4M10 during the operational cycling of the battery pack, an electrically insulating sheet-like carbon layer 4M04 can be formed into a uniform thin film layer with a Young's modulus of approximately >6 GPa. Graphene oxide, as a material with a Young's modulus of 380–470 GPa, is a suitable carbon-based candidate for achieving adequate Li dendritic growth suppression. Compared to conductive graphene, graphene oxide is electrically insulating and prevents Li dendritic deposition on top of the electrically insulating sheet-like carbon layer 4M04. Instead, any Li present will deposit beneath the electrically insulating sheet-like carbon layer 4M04 due to its blocking and insulating properties; more precisely, some Li+ ions 4M12 will adhere to the underside of the electrically insulating sheet-like carbon layer 4M04 rather than forming long dendritic structures extending towards the cathode. Graphene oxide sheets can be overlapped to form the electrically insulating sheet-like carbon layer 4M04 as a conformal film. However, this conformal graphene oxide film may induce high impedance. Therefore, adding an assembly of carbon nano-onions 4M12 can create gaps within the overall graphene oxide stack (and thus the electrically insulating sheet-like carbon layer 4M04), which reduces the impedance of enhanced Li transport (via, for example, one or more paths 4M14 toward the cathode 4M02) and allows the film to be better released from the PET matrix.

[0301] Carbon nano-onions with a relatively high surface area of, for example, about 10 m2 / g to 90 m2 / g, more preferably about 30 m2 / g, will facilitate the adsorption of polysulfides (PS), thereby preventing PS anions from reaching the Li metal anode surface and undergoing chemical reduction to form Li2S(S), which would lead to irreversible sulfur and lithium capacity loss.

[0302] Electrically insulating sheet-like carbon layers, such as 4M04, can be fabricated substantially without binders. Compared to films composed of individual particles held together by binders, the two-dimensional shape of graphene oxide allows for more efficient packing between individual graphene oxide sheets, resulting in a denser film strongly held together by high interlayer π-π bonds. Furthermore, the sheet-like stacking of graphene oxide suppresses crack growth due to the complex, high-surface-area paths required for crack propagation perpendicular to the graphene oxide sheets, thus improving film integrity. Additionally, conventional binders fill the voids between carbon particles, creating high impedance for lithium-ion transport. Moreover, graphene oxide can react with Li metal to form LiOH as a stable SEI. Since graphene oxide is insulating, it will not interact with the electrolyte to form an SEI on the carbon surface.

[0303] The electrically insulating sheet-like carbon layer 4M04 can optionally include various types of carbon with variable porosity, surface area, surface functionalization, and electronic conductivity to influence the reactivity of carbon with contaminants from the surrounding environment (outside the solid Li metal foil anode 4M10), such as components of the electrolyte in a Li battery, such as PS. The layer may include binders or other additives to supplement the carbon sheath to produce a sheath with variable density, porosity, carbon fraction, reactivity, and electronic conductivity, and can readily conduct lithium ions or lithium-containing molecules to facilitate lithium shuttle between the cathode and anode. The preferred use of the carbon disclosed herein is to capture unwanted contaminants prevalent in the electrolyte and prevent these contaminants from reacting with the Li surface, and rather with the surface of the electrically insulating sheet-like carbon layer 4M04. As determined by the manufacturing method and composition of the electrically insulating sheet-like carbon layer 4M04 (which primarily comprises carbon), the layer must have excellent adhesion to Li.

[0304] Figure 4N is an exemplary schematic diagram of a roll-to-roll apparatus 4N00 for fabricating a carbon / lithium anode such as the protected electrode 4M00 of Figure 4M. Figure 4M shows an electrically insulating sheet-like carbon layer 4M04 deposited on a solid Li metal foil anode 4M10. The roll-to-roll apparatus 4N00 can be assembled to transfer a carbon-containing coating (used to generate or provide the electrically insulating sheet-like carbon layer 4M04) from another substrate to a Li surface (such as the surface of the solid Li metal foil anode 4M10 that will be exposed to the electrolyte 4M08 after fabrication) using any compression method such as roll-to-roll lamination and release.

[0305] The carbon / lithium anode can be manufactured by using any known technique, employing any compression method such as roll-to-roll lamination and release, to transfer a carbon-containing coating, represented in Figure 4N by a carbon interface 4N06 on a release film 4N04 cast onto a polyethylene terephthalate (PET) release film, from another substrate to a Li surface. For example, an electrically insulating sheet-like carbon layer 4M04 comprising graphene oxide and carbon nanoparticles can be prepared by first mixing to form a slurry, then casting the slurry onto a PET release film such as release film 4N04 and drying it under vacuum at 60°C. After drying, the film is then transferred in a drying chamber environment via roll lamination (e.g., by rotating a first roll 4N02 and a second roll 4N12 respectively) onto a lithium-sheathed copper foil formed by compressing a Li layer 4N08 onto a copper foil 4N10.

[0306] Applying pressure to transfer the carbon interface 4NO6 self-release film 4NO4 to the Li layer 4NO8 can be achieved, for example, by rolling the carbon interface 4NO6 (such as when it is prepared as a protective carbon layer) onto the Li layer 4NO8 and subsequently releasing the release film 4NO4. After this action, the carbon interface 4NO6 will adhere firmly to the Li layer 4NO8 due to the inherent adhesion properties of Li metal. Therefore, the binder Li metal will assist the self-release film 4NO4 in releasing the carbon interface 4NO6, thereby completing the fabrication of the protected electrode 4M00 shown in FIG. 4.

[0307] In addition to the assembly of the protected electrode 4M00 shown in Figure 4M produced by the roll-to-roll equipment 4N00, several alternative assemblies are possible. For example, CNO can be substituted or added to, and include, one or more other carbon allotropes, each exhibiting different chemical and mechanical properties. Nanodiamond (also known as "diamond nanoparticles") may include diamond with a size of less than 1 micrometer, which can be widely dispersed and thus strengthens the electrically insulating sheet-like carbon layer 4M04 and enhances various properties including mechanical stability and electrical insulation, is non-SEI formed, and is protected from the invasion of polysulfide (PS) species into the solid Li metal foil anode 4M10 (or a carbon-based anode containing Li). Other carbon-based substances that can be dispersed throughout the electrically insulating sheet-like carbon layer 4M04, in addition to or as a substitute for nanodiamond, may include: [‧] Carbons such as SP2 mixed carbon, reduced graphene oxide (rGO) and / or various forms or types of graphene can cause the stacking and layer formation of one or more layers of electrically insulating sheet-like carbon 4MO4; [‧] The stripped and oxidized carbon, which is incorporated into the electrically insulating sheet carbon layer 4M04, imparts a more uniform layered structure to it; solvents such as tetrabutylammonium hydroxide (TBA) and dimethylformamide (DMF) can be applied to the stripped and oxidized carbon incorporated into the electrically insulating sheet carbon layer 4M04 to impart better wetting of the carbon, thereby achieving better carbon dispersion uniformity throughout the electrically insulating sheet carbon layer 4M04; [‧] Fluorinated graphene is added to a carbon slurry, which includes one or more of the 3D hierarchical carbon structures or aggregates disclosed in this invention to enhance the SEI formation reaction between the exposed carbon and Li metal, all of which do not interfere with the layered structure of the protected electrode 4M00; [‧] Add the dopant to the crystalline structure of carbon incorporated into the electrically insulating sheet-like carbon layer 4Mo4; or add one or more functional groups to one or more doped carbons in the carbon-based support or matrix incorporated into the electrically insulating sheet-like carbon layer 4Mo4; [‧] Functionalized carbon, especially functionalized carbon with F and Si groups, is added to the electrically insulating sheet-like carbon layer 4MO4, which may be included inside or deposited below the layered carbon barrier to form a stable SEI on the Li and carbon mesophase; and [‧] Functionalized carbon, such as silicon- and / or nitrogen-functionalized carbon, is added to the electrically insulating sheet carbon layer 4M04, either included in or deposited on top of the electrically insulating sheet carbon layer 4M04 to prevent polysulfide (PS) from diffusing and migrating to the surface of the Li metal exposed to the electrolyte 4M08.

[0308] Furthermore, the addition of specific polymers / crosslinking agents (such as any or more of the polymers / crosslinking agents referenced in Table 4D00 shown in Figure 4D) can improve the mechanical properties of the electrically insulating sheet carbon layer 4M04 and enhance Li ion transport and / or flux in the electrically insulating sheet carbon layer 4M04 (as shown by one or more paths 4M14 in Figure 4M). Other examples of polymers that enhance Li ion transport include poly(ethylene oxide) and poly(ethylene imine), while examples of linkers that can be used to crosslink carbon together include inorganic linkers (such as borates, aluminates, silicates), multifunctional organic molecules (such as diamines, glycols), polyureas, and high molecular weight (MW) carboxymethyl cellulose (CMC).

[0309] Additional or alternative methods for manufacturing the electrically insulating sheet carbon layer 4M04 and / or depositing the electrically insulating sheet carbon layer 4M04 onto the protected electrode 4M00 include spraying; casting the carbon layer slurry onto a perforated film to obtain better release; then casting the carbon layer slurry onto a spacer for direct cell assembly without release; and vacuum filtering the electrically insulating sheet carbon layer 4M04 onto the spacer with or without calendering-lamination.

[0310] Referring to Figure 4B, either or more of the A-SEIs described as either the A-SEI-protected anode 4B00 or the protected electrode 4M00 (protected by an electrically insulating sheet-like carbon layer 4M04) can be removed from a competitor's battery to expose the interface coating on the anode surface, which can then be further analyzed using various test methods such as those described below. [‧] Disassembly analysis using X-ray powder diffraction (XRD), mass spectrometry, and visual inspection via scanning electron microscopy will reveal inherent material properties within the observed or assessed structure, such as the lamellar morphology of the included carbon; and [‧] Mechanical testing of the anodes of competitors will reveal similarities to any or more of the protective carbon interface layers disclosed in this invention. [ Example ] [ ]

[0311] Figure 40 is an image of an exemplary protective carbon interface (PCI) 4000 deposited on a Li anode, such as the Li anode shown in Figure 4M by means of a protected electrode 4M00, according to some embodiments. The PCI layer may comprise different carbon allotropes mixed together to produce a homogeneous dispersion, which is then directly transferred by a roll-to-roll transfer performed on a Li metal foil, such as the roll-to-roll transfer described by the roll-to-roll device 4N00 shown in Figure 4N. The PCI layer 4000 maintains a relatively stable average charging voltage, indicating that no unwanted parasitic side reactions occur within the battery pack thus equipped during cycle operation.

[0312] Figure 4P shows the electrode specific capacity performance of a Li anode protected by the protective carbon interface (PCI) 4O00 shown in Figure 4O, according to some embodiments, as a function of cycle number 4P00, compared to a reference pure Li metal electrode. As shown, the reference Li metal electrode exhibits a sharp decrease in capacity after approximately 25 cycles. This sharp decrease in capacity is caused by parasitic reactions occurring on the surface of the Li anode exposed to the electrolyte, resulting in dendrite formation on the surface of the Li anode and a corresponding increase in anode impedance. In contrast, the PCI layer prevents the sudden and sharp drop in capacity caused by high impedance due to the interface layer's ability to prevent such a drop.

[0313] Figure 4Q shows the coulombic efficiency of a Li anode protected by the protective carbon interface (PCI) 4O00 shown in Figure 4O, relative to the number of cycles, according to some embodiments. The coulombic efficiency shown in Figure 4Q indicates that the reference Li metal electrode experiences a sharp anomaly in efficiency (such as a decrease) starting from cycle 30 (as shown by the unstable behavior at the data point), while the PCI 4O00 maintains a stable efficiency level throughout the cycle. The unstable efficiency data in the reference Li metal electrode corresponds to high-level Li dendritic growth. This is further confirmed by the average charge voltage data shown in Figure 4R.

[0314] Figure 4R shows the average charging voltage of a Li anode protected by a protected carbon interface (PCI) relative to the number of cycles, according to some embodiments (scheme 4R00). As shown, the average charging voltage of the reference Li metal electrode increases rapidly, while the PCO layer (corresponding to PCI 4O00 shown in Figure 4O) remains relatively constant, indicating the absence of Li dendritic growth.

[0315] Figure 4S shows another diagram, 4S00, of cycling data for various full-capacity batteries (with a limited lithium supply), each in coin cell format. According to some embodiments, the electrode specific capacity (in mAh / g) of a Li anode protected by a protective carbon interface (PCI) is compared with that of a nanodiamond layer, a reference pure Li metal electrode, and a non-uniform interface layer. As shown, without a protective interface layer, the reference Li degrades rapidly. The protective carbon interface layer (corresponding to PCI 4O00 shown in Figure 4O) shows the best capacity retention, followed by the nanodiamond layer. The non-uniform (carbon) interface layer with visible defects on its surface actually performs worse than the reference Li lithium, indicating that the uniformity of lithium surface coverage and the integrity of the interface layer are critical parameters.

[0316] Figure 4T shows an image of a reference cell disassembly 4T00 of an exemplary reference lithium pouch cell, showing highly dendritic growth entering the spacer (shown in region 4T02). Here, the dendritic growth is shown as the transfer (growth) of a black moss-like structure in region 4T02.

[0317] Figure 4U shows an image of a Li anode, exemplarily protected by a carbon-containing layer, such as the protected electrode 4M00 shown in Figure 4M, after disassembly 4U00. This image shows the absence of the moss-like black protrusions seen in region 4T02 of the reference battery disassembly 4T00 shown in Figure 4T. Instead, disassembly 4U00 shows only a few traces of the delaminated PCI adhering to the spacer during disassembly.

[0318] Conversely, the spacer depicted in Figure 6 is not devoid of any of the moss-like black protrusions found in the reference cell. Rather, it has several spots of layered LPCI that adhered to the spacer during deconstruction.

[0319] Figure 5 shows an exemplary Li-ion or LiS rechargeable battery system 500, having an anode 501 and a cathode 502 separated by a spacer 517. Either or more of the anode 501 and cathode 502 may be substantially formed from the lithium-ion carbon support 400A shown in Figure 4A, and is represented here in simplified form by larger and smaller carbon particles 509, all of which at least partially confine a Li-ion conductive electrolyte solution 518 containing a dissociated Li-ion conductive salt 505 as shown. The spacer (a porous membrane electrically isolating the anode 501 and cathode 502 from each other) is also located as shown. Individual Li ions migrate back and forth between the electrodes of the Li-ion battery pack via path 507 during discharge-charge cycles, and are sandwiched within the carbon-based active material to form either or more of the anode 501 and cathode 502, confined therein as needed, to achieve optimal rechargeable battery 500 performance.

[0320] Electrolytes, such as electrolyte solutions 518, can generally be classified into several broad categories, including liquid electrolytes and solid electrolytes. Liquid electrolytes are the most commonly used electrolyte systems in many conventional battery packs due to their higher ionic conductivity, lower surface tension, lower interfacial impedance, and good wettability within the electrodes. In Li₂S battery pack systems, liquid electrolytes dominate because they help compensate for the unfavorable electrochemical kinetics of the large amount of potentially encountered sulfur (S) and lithium sulfides (Li₂S). In Li₂S systems, liquid electrolytes containing ether-based solvents can be used because, unlike carbonates, ether-based solvents do not react adversely with S and generally have better Li ion transport characteristics. Potential disadvantages of using ether-based electrolytes include the solubility of long-chain polysulfides (PS), which can be attributed to PS shuttle, electron migration, and cathode volume expansion, ultimately leading to the degradation of the Li₂S electrochemical cell and compromising its structural integrity.

[0321] In addition to conventional liquid electrolytes, solid electrolytes can potentially be configured to stop the formation and growth of Li dendritic crystals, and to stop PS shuttle when the solid electrolyte effectively converts the LiS system from a multiphase system to a single-phase system, thus preventing internal short circuits, electrolyte leakage, and flammability. Solid polymer electrolytes can be defined as porous membranes capable of transporting Li ions across the membrane. Solid electrolytes can be further classified into solid polymer electrolytes, gel polymer electrolytes, and non-polymer electrolytes. Solid polymer electrolytes can be composed of lithium salts dissolved in a high molecular weight polymer matrix. Common polymer matrices used include polyethylene glycol (PEO), polyvinylidene fluoride (PVDF), poly(p-phenylene oxide) or poly(PPO), poly(vinylidene fluoride-copolymer-hexafluoropropylene) (PVDF-HFP), and poly(methyl methacrylate) (PMMA), etc.

[0322] Gel polymer electrolytes can be similar to solid polymer electrolytes because they contain a high molecular weight polymer and also include a liquid component tightly trapped within a polymer matrix. In some embodiments, gel polymer electrolytes are developed to compensate for the poor ionic conductivity observed in solid polymer electrolytes. Non-polymer solid electrolytes offer advantages over other forms of solid electrolytes, including higher thermal and chemical stability.

[0323] Non-polymer solid electrolytes are composed of ceramics, and commonly found non-polymer electrolytes include superionic conductors (LISICON), Li7La3Zr2O12 (LLZO), Li7La2.75Ca0.25Zr1.75Nb0.25O12 (LLCZN), Garnet, and Ge-doped Li0.33La0.56TiO3 (Ge-LLTO) perovskites, with thicknesses ranging from approximately 0.5 μM to 40 μM. They can be configured to substantially prevent either or more of the formation or growth of Li dendrites. Nevertheless, some solid electrolytes may still present certain challenges, including relatively poor Li ion conductivity and weight. At the thickness required to prevent Li dendrite growth, the observed ionic impedance may be very high, making it impossible for such Li-ion or LiS battery packs to function as required, while at thicknesses requiring acceptable Li ion conductivity, Li dendrite growth may not be prevented.

[0324] During discharge, Li is removed from the intercalation zone of anode 501. The active material of cathode 502 may include mixed oxides. The active material of anode 501 may primarily include graphite and amorphous carbon compounds, including those presented herein. These materials are intercalated with Li.

[0325] Li-ion conducting salt 505 can dissociate to provide mobile Li ions that can be intercalated into one or more of the unique carbon-based structures disclosed herein. These Li ions can be incorporated into one or more of the anode 501 or cathode 502 as structural materials to achieve a specific capacity retention of more than 1,100 mAh / g or higher, as promoted by the associated microstructure 107E. Li ions form complexes and / or compounds with S in the LiS system and are temporarily confined during charge-discharge cycles to levels that cannot be otherwise achieved by conventionally unorganized carbon structures (requiring definition and combination via adhesive forces), which can also suppress overall battery pack performance and durability, as previously discussed.

[0326] The interconnected microstructure 107E shown in Figure 1E contains pores 105E, which can form carbon-based particles 100A, 100D, 402A, and / or their analogues and are used to generate conductive hierarchical films of either or more of the anode 501 or cathode 502. These pores can be defined during synthesis to include a micropore volume (pore size < 1.5 nm). Sulfur (S) is infused into pores 105E via capillary forces, where S is confined. This successful micron-confinement of sulfur prevents dissolved polysulfides (PS) (as previously presented with the LiS system) from re-precipitating to the outside of their original pores. To achieve an activated carbon composite that retains an achievable amount of S, a pore volume of 1.7 cc / g is required, all of which results in a pore opening of < 1.5 nm.

[0327] Operationally, in a Li-ion or LiS system, Li ions migrate from the anode 501 to the cathode 502 via the electrolyte 518 and the spacer 517. Here, as shown in magnified regions 516 and 513, molten Li metal 514 micrometers is confined within a few-layer graphene sheet 515 associated with either of the carbon-based structures disclosed in this invention that serve as the structure of the anode 501 or the cathode 502. The molten Li metal can dissociate in the anode 501 according to the following equation (8): (8) FLG-Li FLG + Li+ e-

[0328] Equation (1) shows that electrons 506 and 511 discharge 508 to supply power to an external load, causing Li ions 512 that have migrated to the cathode 502 to return to a thermodynamically favorable position within the cobalt oxide-dominated lattice according to the following equation (9): (9) xLi+ + xe- +Li1-xCoO2 LiCoO2.

[0329] During charging, the process is reversed, in which Li ions 505 are transferred from the cathode 502 to the anode 501 via the electrolyte 518 and the spacer 517.

[0330] The revealed carbon-based structures, see the unexpectedly favorable specific capacity values ​​achieved through the unique multimodal hierarchical structure of carbon-based particles 100A, 100D, and / or their derivatives (including carbon support 300B and lithium-based carbon support 400A). Any or more of these structures can be combined to produce the traditional advantages offered by Li-ion technology. Compared to sodium or potassium ions, the relatively small Li ions exhibit significantly faster kinetics in various oxide cathode materials. Another difference includes the reversible intercalation and deintercalation of Li ions within graphite and silicon (Si), unlike other alkali metals. Furthermore, lithium-based graphite electrodes enable higher battery voltages. Therefore, due to the unique stacking of few-layer graphene (FLG) (such as 5 to 15 layers of graphene arranged in a generally horizontal stack), the ease with which carbon-based materials can reversibly sandwich and de-sandwich Li ions between graphene sheets is revealed, as in the use of carbon-based particles 100A and / or their analogues, and is suitable for applications such as hard-shell, pouch cells and prisms. [ Artificial solids are created through doping ] [ and ] [ Electrolyte interface ] [ (SEI) ] [ Membrane stabilization ] [ ]

[0331] Currently, when an electrolyte is first introduced followed by initial discharge and charge steps, current Li-ion battery packs form a protective passivation layer (such as passivation layer 418A shown in Figure 4A) or solid electrolyte interface (SEI) on the electrode surface exposed to the electrolyte during the preconditioning step. Although electrolyte chemistry and pretreatment schemes, such as charge / discharge rates and overvoltages, can be adjusted to optimize membrane passivation (see SEI formation), conventional membrane layers incorporated into the electrodes can still exhibit chemical and mechanical instabilities.

[0332] Referring now to FIG. 6A, a specific element 602A can be introduced into the aforementioned carbon material 600A by doping. Elements 602A such as silicon, sulfur, nitrogen, and phosphorus can be coated onto the electrode surface 601A of the carbon structure at a defined level, such as from a sparse decoration to a complete conformal coverage. The formation of a stable solid electrolyte ion conduction layer has been reported in the literature; see thioLISCON dominated by sulfur, which is defined as a lithium-sulfur conductor with the chemical formula Li3.25Ge0.25P0.75S4, and NASCION dominated by phosphate, such as sodium (Na) superionic conductors, which generally refer to a family of solids with the chemical formula Na1+xZr2SixP3-xO12 (0 < x < 3), and abbreviations are also used for similar compounds where Na, Zr, and / or Si are replaced by isovalent elements. As explained herein, the formation of a stable solid passivation layer includes doping a specific element 602A, and the electrode surface 601A can be engineered before battery assembly so that the formation process of the stable solid ion conduction layer is decoupled from the reduction / oxidation events that occur when in contact with the electrolyte, as encountered in current Li-ion battery manufacturing, which still often suffers from long-term stable operation.

[0333] In combination with conductive particles such as carbon black and an optional polymer binder and a solvent such as NMP, any one or more of the tuned 3D hierarchical graphene-based particles disclosed herein can be directly incorporated into the following conventional slurry-cast electrode manufacturing process: replacing graphite particles with active graphene (FLG) in the case of anodes; and / or infusing with active sulfur (S) in the case of cathodes.

[0334] The 3D graphene particles provide interconnected mesoporous ion conduction channels for rapid Li-ion transport for higher specific capacity graphene building blocks, as well as carbon black and a binder to ensure a conductive path, such as defined by graphene sheets 101B used as the structural material for the continuous microstructure 107E, which also provides mechanical integrity.

[0335] The disclosed carbon materials can be prelithiated by ball milling and / or thermal annealing and electrochemical reduction from a third electrode, either at a relatively low concentration to offset the first charge Li loss of a conventional oxidized cathode cell; or at a relatively high concentration to increase the total specific capacity of both oxidation and alternative cathode formulations, and then casting the slurry into the electrode.

[0336] Figures 6B1 and 6B2 show schematic diagrams comparing a chemically non-reactive system 600B1 with a chemically reactive system 600B2 under conditions of active material wetting and lithium (Li) confinement within the active material, according to some embodiments. Although molten Li metal is wetting into any or more of the carbon-based structures (such as interconnected microstructures 107E) disclosed in this invention as shown in Figures 1A to 1E, alternative or additional embodiments provide the infusion of molten Li metal droplets into pores, such as pores 105E, in the gas phase. In the chemically non-reactive system 600B1, the preparation of Li metal droplets, or the expectation that the Li metal droplets will fail to react with carbon upon contact with an exposed carbon surface, is due, for example, the hydrophobicity of Li to carbon. In any case, infusing vapor phase Li droplets with an internal contact angle (θ) between approximately 50° and 90° can provide a balance between competing liquid and solid adhesion forces, such as the adhesion forces observed between liquid phase molten Li droplets (such as those used to provide Li ion 108E) and solid carbon (γsl), which is proportional to the adhesion force (γlv) in the liquid.

[0337] Wetting between gaseous Li and solid carbon is defined as the ability of a liquid to maintain contact with a solid surface, arising from intermolecular interactions when the two come into contact. The degree of wetting, or wettability, can be determined by the force balance between adhesive and cohesive forces. The desired degree of wetting can occur when the adhesive energy is close to the viscous energy, such as in liquid metals dispersed on a solid metal, or in semiconductors including silicon (Si), germanium (Ge), or silicon carbide (SiC), and in ceramics including any or more carbides, nitrides, or borides, exhibiting near-metallic properties to exposed surfaces. Furthermore, using liquid metals with relatively high solubility for atmospheric pollutants such as oxygen (O), nitrogen (N), or moisture (H₂O vapor) or carbon can reduce the contact angle observed or required during wetting on contaminated solid surfaces or pure carbon surfaces.

[0338] In the chemically reactive system 600B2, wetting of a carbon surface layer 602B2, such as on the surface of carbon-dominant particles 100A exposed to Li metal, can be accompanied by chemical reactions occurring at that interface, such as dissolving solid carbon material or forming a new 3D layer 604B2, or involving compounds that at least partially consume the underlying carbon surface layer 604B2. Adding dopants tuned by type and concentration to the carbon surface layer 602B2 can also affect the degree of wetting, as shown by various fluid positions 606B2, 608B2, and 610B2, exhibiting minimal wetting at position 606B2 and progressively larger wetting at positions 608B2 and 610B2, respectively. In some embodiments, the formation of the new 3D layer 604B2 may alter the properties of the underlying carbon surface layer 602B2, including electrical conductivity, or may otherwise restrict the wetting of the reaction products (shown as the new 3D layer 604B2) by forming volume expansion into the porous medium.

[0339] For the chemically non-reactive system 600B1 or the chemically reactive system 600B2, reducing the contact angle of liquid Li metal droplets (such as the droplets shown at position 610B2) promotes the wetting of the underlying carbon surface layer 602B2. Furthermore, for the carbon surface layer 602B2, which contains adsorbed or chemically bonded oxygen (O), adding elements with high O solubility (such as gas absorbers) can reduce or otherwise control the O activity at the new 3D layer 604B2. For solid variants of the carbon surface layer 602B2, adding elements such as nickel (Ni), iron (Fe), or other elements to a liquid-phase metal with high carbon solubility ensures relatively high surface activity or affinity.

[0340] Figure 7 illustrates an example process flow according to some embodiments, in which molten Li metal is impregnated into the void spaces between carbon aggregates to initiate a reaction at the exposed carbon surface. Considerations for impregnating Li metal 704, 706 into the encapsulated carbon support 702 are shown in schematic diagram 700 of the impregnation process flow. These considerations can be incorporated into any or more of the carbon-based structures disclosed herein (such as carbon particles 100A shown in Figure 1A or interconnected microstructures 107E shown in Figure 1E) or additionally provided as structural materials. The surface conditions of the carbon support 702 can be tuned prior to impregnation with molten Li metal, which can be introduced into the carbon support 702 by either capillary infusion of molten Li metal in a liquid phase or by infusion of molten Li metal droplets suspended in air, thereby forming Li metal vapor. Precise tuning of the following conditions at the surface of the carbon support 702 exposed to the introduced Li includes controlling: ● Air pollutants, such as moisture (H2O vapor), oxygen (O), nitrogen (N), and hydrocarbons formulated with restrictions or containing physiologically or chemically adsorbed O; ● Nitrogen bonds are formed on the surface during plasma post-treatment; and ● The purity of Li metal, such as controlling common surface oxides, nitrides and carbonates.

[0341] Li wetting can be initiated by capillary infusion of molten Li metal 704 or 706 to disperse and fill within the carbon support 702, thereby forming a lithium-ionized carbon compound 708 that encapsulates the voids in the carbon support 702. Subsequent steps may include non-reactive Li wetting and post-reaction treatment. Various specific methods exist for wetting Li into the carbon support 702, including:

[0342] Figure 8A shows an equation modeling the rate at which Li is infiltrated into one or more of the porous regions of a currently presented carbon-based structure, such as the carbon-based particles 100A shown in Figure 1A, the pores 105E shown in Figure 1E, and the connecting paths 107E. The infiltration rate can be controlled by the non-reactive viscous resistance of a liquid metal, such as molten Li, followed by a chemical reaction between the liquid metal and carbon according to Washburn's equation 800A shown in Figure 8A, resulting in carbides, where σ and η are the surface tension and viscosity of the liquid, respectively, θ is the contact angle, and reff is the effective pore radius of pores such as pores 105E shown in Figure 1E, which can be distributed throughout the carbon-based scaffold, such as the carbon-based scaffold 702 shown in Figure 7. Therefore, as can be seen from the various coefficients used in Washburn Equation 800A, capillary flow is effectively represented by modeling the carbon-based preform structure as a theoretical parallel cylindrical bundle.

[0343] Figure 8B shows a non-reactive system 800B according to some embodiments, including a non-wetting compound 802B and a self-wetting compound 804B. For example: ● In the non-wetting compound 802B, pressure (P0) is applied to overcome capillary pressure, such as the pressure between two immiscible liquids in a thin tube caused by the interaction of forces between the liquid and solid walls of the tube, and may be limited by viscous friction, such as the viscous friction that has been determined and characterized by Washburn equation 800A; L may represent a liquid phase Li layer, such as a liquid phase Li layer provided by molten Li metal, S may represent a solid carbon surface exposed to L, θ may represent the contact angle between L and S, and V may represent viscous friction, and the contact region between L and S is characterized by Washburn equation 800A; ● In the spontaneously wetting compound 804B, θ is maintained at an angle <60° to achieve non-reactive Li wetting of the carbon-based support; and ● Any or more of the non-wetting assembly 802B or the spontaneously wetting assembly 804B may be incorporated into or otherwise implemented in the exemplary carbon-based support 806B, which may be part of any or more of the carbon-based structures disclosed in this invention.

[0344] Figure 8C shows a reactive system 800C according to some embodiments, including a wettable reactive product layer assembly 802C and an unwettable surface layer assembly 804B. The wettable reactive product layer assembly 802C may involve the formation of a new 3D layer 806C, similar to the previously discussed layers associated with the chemically reactive system 600B2 shown in Figure 6B2, wherein the formation of the new 3D layer 604B2 or compound involves at least partial consumption of the base carbon surface layer 604B2. Herein, solid carbon material S may be at least partially consumed to produce or generate a new 3D layer 806C that may be or include LiC6. In contrast, in the unwettable surface layer assembly 804B, such as a surface of S directly facing in the vertical direction, L is not reactive such that the intrusion of L into the capillary open regions causes a consumption reaction with S to produce a new 3D layer 808C only along those capillary open regions.

[0345] Figure 9 shows a flowchart 900 of a method for lithiation and alloying of carbon-based structures according to some embodiments. At block 902, oxide thermal decomposition can be used to activate the carbon surface in the encapsulated preform by initiating a surface-interface reaction via lithium (Li) vapor pressure. At block 904, in an example where the Li film is impregnated into a metal substrate, surface-active element compounds can be vaporized to decompose oxide flux and / or promote wetting. At block 906, as part of the impregnation process, alloying elements such as silicon (Si), aluminum (Al), and potassium (K) can be incorporated to promote impregnation / manage oxygen activity at the interface.

[0346] Figure 10A shows a flowchart of method 1000A for preparing a carbon-based structure to undergo lithiation according to some embodiments. In block 1002A, procedures for testing lithium foil / powder preforms can be established. In block 1004A, alternative metal powder preforms can be used to promote non-reactive wetting, while understanding reproducible schemes for managing lithium, such as surface pretreatment / impurity management. In block 1006A, carbon surface activity / pretreatment schemes can be evaluated by measuring the thermal activation reaction using various techniques, including thermogravimetric analysis (TGA) and / or differential scanning calorimetry (DSC).

[0347] Figure 10B shows a flowchart of another method 1000B for preparing Li materials suitable for lithiation operations according to some embodiments. At block 1002B, the heated pressure plate can be calibrated and the material thermally profiled. At block 1004B, the glove box environment, such as conditions or settings involving humidity and oxygen, can be measured before, during, and after testing. At block 1006B, samples can be prepared from any or more of vaporized lithium, carbon powder, and other substances on lithium foil and / or metal foil.

[0348] Figure 10C shows a flowchart of a method 1000C for nucleating multiple carbon particles at a first concentration criterion. At block 1002C, multiple carbon particles can be nucleated at a first concentration criterion to form a first film on a sacrificial substrate, each carbon particle comprising multiple aggregates including multiple few-layer graphene sheets fused together. At block 1004C, a porous structure can be formed based on the multiple fused few-layer graphene sheets. At block 1006C, molten Li metal can be infused into the porous structure.

[0349] Figure 10D shows a flowchart of a method 1000D for nucleating multiple carbon particles at a second concentration level. At block 1002D, carbon particles can be nucleated on a first membrane at a second concentration level. At block 1004D, a second membrane can be formed based on the carbon particles at the second concentration level.

[0350] Figure 10E shows a flowchart of the method 1000E for growing carbon particles. At block 1002, carbon particles can be grown on a roll-to-roll processing device.

[0351] Figure 10F shows a flow chart of method 1000F for vaporizing molten Li metal. At block 1002E, molten Li metal can be vaporized onto a metal foil. At block 1004E, molten Li metal can be rolled from the metal foil into a porous structure.

[0352] Figure 10G shows a flowchart of method 1000G for preparing an anode to participate in the reversible migration of Li ions. At block 1002G, an anode can be prepared to participate in the reversible migration of Li ions together with a cathode. The cathode is prepared by one or more of chemical functionalization or sulfidation.

[0353] Figure 10H shows a flowchart of method 1000H for densifying multiple graphene sheets. At block 1002H, multiple graphene sheets can be densified on the porous structure.

[0354] Figure 10I shows a flowchart of a method 1000I for depositing a first plurality of carbon particles to form a first film. At block 1002I, a first plurality of carbon particles can be deposited to form a first film on a substrate, the first film being assembled to provide a first conductivity. At block 1004I, a plurality of 3D aggregates formed from few-layer graphene sheets orthogonally fused together are assembled to define a porous structure. At block 1006I, a porous configuration can be formed within the porous structure. At block 1008I, molten Li metal can be infused into the pore structure.

[0355] Figure 10J shows a flowchart of the method 1000J for depositing a second plurality of carbon particles. At block 1002J, a second plurality of carbon particles can be deposited on the first film. At block 1004J, a second film can be formed based on the second plurality of carbon particles.

[0356] Figure 10K shows a flow chart of the method 1000K for wetting molten Li metal. At block 1002K, molten Li metal in the gas phase can be wetted into the void structure. At block 1004K, a chemical reaction can be initiated between any one or more Li ions provided by the molten Li metal and one or more exposed surfaces of the void structure. At block 1006K, one or more lithiophilic surfaces can be formed from one or more exposed surfaces.

[0357] Figure 10L shows a flowchart of method 1000L for coating one or more of the lithiophilic surfaces. At block 1002L, one or more of the lithiophilic surfaces can be coated with active elements including halogens and gas-absorbing agents including titanium (Ti) oxides.

[0358] Figure 10M shows a flowchart of method 1000M for coating one or more of the lithiophilic surfaces. At block 1002M, one or more elements, including silicon (Si) or aluminum (Al), having a surface energy lower than that of Li, can be used to coat one or more of the lithiophilic surfaces. At block 1004M, one or more elements having a surface energy lower than that of Li can be used to promote Li wetting enhancement of one or more of the lithiophilic surfaces.

[0359] Figure 10N shows a flowchart of the method 1000N for generating an adhesive. At block 1002N, the adhesive can be generated by incorporating one or more of metal powder or metal-containing compounds, including silicon carbide (SiC), into a carbon scaffold.

[0360] Figure 100 shows a flowchart of method 10000 for adding a certain amount of dopant. In block 10020, a certain amount of dopant can be placed at the interface. In block 10040, the degree of Li wetting corresponding to this amount of dopant can be affected.

[0361] Figure 10P shows a flowchart of method 1000P for controlling hydroxyl (hydroxyl / hydroxyl, OH) adsorption. At block 1002P, hydroxyl (OH) adsorption can be controlled at any one of the exposed surfaces of the pore structure.

[0362] Figure 11A shows a flow chart of lithium filling method 1100A. At block 1102A, lithium can be filled using roll-to-roll boiler brazing or spontaneous wetting. At block 1104A, a two-dimensional (2D) analogue with a 2D liquid interstitial filler can be used. At block 1106A, the filled lithium metal can chemically react with the exposed carbon surface at the liquid-solid interface, and the flux used for activation, increasing and / or decreasing surface tension, and controlling the thermodynamic kinetics can be controlled. At block 1108A, rapid screening of lithium wettability can be performed by using a halogen interlayer to decompose Li₂O in the presence of Li foil / carbon particle stacks on a hot plate.

[0363] Figure 11B shows a flowchart of method 1100B for vaporizing lithium (Li) onto a metal foil. At block 1102B, lithium can be vaporized onto the metal foil, which can act as a thermal conductor. At block 1104B, copper can be optionally used as a current collector and / or tantalum can be used for release to achieve minimal chemical interactions. At block 1106B, the film thickness can be tuned to match the pore volume in the encapsulated carbon-based particles and / or structure.

[0364] Figure 11C shows another flowchart of the preparation of carbon particles using a method such as lithiation via a process called pre-lithiation (1100C). At block 1102C, the load to be applied (such as a burnished roll) can be oriented onto the top of a carbon particle-filled bed or a pre-lithiated and / or pre-formed foil under dry chamber conditions. At block 1104C, overall isothermal conditions (such as at approximately 180°C and / or immediately below the melting point of Li) can be generated across Li and the encapsulated particles under conditions of rapid thermal spikes at concentrated loading locations. At block 1106C, an exothermic reaction can be used to initiate wetting, followed by capillary-driven fluid flow in the porous carbon medium, utilizing principles related to Darcy's law and Washburn with variable permeability. Capillary-driven fluid flow assumes no observable reaction products are formed / accumulated.

[0365] Figure 12 shows a flowchart of a method 1200 for Li infusion of carbon particles during the formation of carbon particles using vaporized Li, according to some embodiments. At block 1202, a metal (such as copper and / or tantalum) foil coated with lithium can be applied, for example, in a vacuum vaporizer; the measured Li volume, such as thickness and density, can be proportionate to the pore volume in the encapsulated particle layer. At block 1204, particles can be assembled into the encapsulated membrane without binders, for example, by scaling up, producing coarse-grained materials (such as films) from fine particles, wherein assembly techniques may include tumbling, pressure pressing, thermal reaction, fusion, drying, agglomeration by liquid suspension, and electrostatics for forming coin-hole-sized discs. At block 1206, intrinsic carbon particles can be formed. At block 1208, the sp2 / sp3 ratio of carbon during formation can be optimized to correspondingly increase lithium (Li) insertion and / or intercalation. At block 1210, contamination from impurities, such as those caused by acetylene and other post-plasma aromatics, can be reduced. At block 1212, post-processing operations can be performed.

[0366] Figure 13 shows a schematic diagram of an idealized anode 1300 assembly having a 3D graphene-based nanostructure 1302 providing structural definition for the anode 1300 according to some embodiments. The 3D graphene-based nanostructure 1302 can be incorporated into or provide structural definition for any one or more of the carbon-based structures disclosed in this invention, including the pores 105E and / or connecting paths 107E shown in Figure 1E, and can restrict or otherwise retain metal dopants such as silicon (Si) 1312 and generate volume expansion during the alloying-dealloying cycle of Li ions 1306 via surface-activated diffusion path 1316, while also restricting electrolyte access. As shown in path 1310, silicon can be redistributed in defects, pores, or wrinkles in at least one layer of graphene sheet and distributed in path 1308 to an adhesive 1304 such as highly polar polyacrylonitrile (PAN). Sulfur (S) doping can be performed or occurs at the graphene 1314-silicon contact region or surface to assist Li recombination and associated charge-discharge cycles in the LiS battery system to achieve one or more of the performance figures cited herein, including a specific capacity greater than 372 mAh / g, which is generally achievable by graphite alone as a theoretical maximum. In some embodiments, graphene oxide can be used in addition to or as a substitute for few-layer graphene, and the LiS system can be immersed in a LiPF6 liquid electrolyte.

[0367] The anode 1300 can be configured with existing or future carbon-based materials, providing reverse compatibility. Li metal can be accommodated via surface-activated diffusion path 1316, and Li can also be interspersed between pairs of few-layer graphene sheets. The pore size of the carbon material can be tuned within the anode 1300 to achieve specific Li distributions or confinement levels and reversible Li ion flow, and can be created using amorphous or crystalline carbon structures.

[0368] Pre-lithiation of the anode 1300 may initially include electrolysis of molten Li metal or direct contact with molten Li metal for a later transition to direct vapor infusion technology. As substantially described previously, the carbon structure used as the forming material for constructing the anode 1300 may be directly deposited as a particle film or deposited from powder as a particle film. The Li efflux rate may be matched to the Li insertion rate within the anode 1300 to avoid excessive exposure to the Li deposited or condensed carbon surface. Furthermore, production and cost considerations for the anode 1300 may include: ● Producing carbon-based materials in low-cost powder form rather than in film form, these low-cost powders are then formulated and dropped into existing Li-ion or LiS battery packs; ● Direct deposition of carbon-based films on a rotating drum without relying on adhesives; and ● When infusing Li into carbon-based particles and structures such as slurry castings / adhesives, evaporation techniques can be used to purify or dry the carbon.

[0369] The Li entrapment of the anode 1300 may include the following procedures established by known coil-to-coil boiler brazing and / or spontaneous wetting techniques, which include one or more of the following: ● Use two-dimensional (2D) analogues with 2D liquid gap fillers; ● Liquid-solid chemical reactions using fluxes for activation; ● Increasing the proportion of solid to viscous surface area and decreasing the proportion of liquid to viscous surface area to control and tune surface tension and / or thermodynamic forces; and ● In the case of Li foil / carbon particle stacks on a hot plate, a halogen interlayer is used to decompose any formed lithium oxide (Li2O) to screen for Li wettability.

[0370] The Li infusion of the anode 1300 may also include the following procedures, techniques, or implementation schemes related to the vaporization of Li on a metal foil assembled to act as a heat conductor: ● Copper (Cu) is selected as the current collector in Li-ion or LiS battery systems with an anode of 1300. ● Tantalum (Ta) is dispersed within the anode 1300 for Li ion release, resulting in minimal overall chemical interactions; and ● Produces a carbon-based film thickness commensurate with the pore volume in the encapsulated particles.

[0371] Furthermore, the Li infusion of anode 1300 may also include the following procedures, techniques, or embodiments related to the orientation of Li and Ta foil on top of carbon particles encapsulated in a bed assembly, which can be prepared in a dry chamber environment to receive loads or pressures provided by a rotary burnishing roll-type drum: ● Carbon particles are prepared in the form of a thin material by forward rotational compression of a burnishing spool or drum, which is coated with a layer of Ta foil and further coated with Li foil. This thin material is placed on a copper foil, wherein heat is applied by the burnishing spool and heat is applied to the Cu foil to melt Li and produce molten Li metal that infiltrates into the carbon particles; ● The process of impregnating Li with encapsulated carbon particles produces overall isothermal conditions such as approximately 180°C, just below the melting point of Li; ● Rapid thermal spikes were observed at the concentrated Li loading sites; and ● Li wetting via an exothermic reaction and capillary-driven flow of molten Li metal in a porous carbon medium, controlled by one or more of Darcy's law, Washburn's equation, etc., with variable permeability, assumes that no observable reaction products are formed or accumulated.

[0372] Furthermore, the Li infusion of the anode 1300 may also include the following procedures, techniques, or implementation schemes: ● In a vacuum gasifier, lithium (Li) is used to coat metal (such as copper (Cu) and / or tantalum (Ta)) foil; the volume of Li, such as thickness and density, is controlled to be commensurate with the pore volume in the encapsulated carbon particle layer or film; ● Carbon particles can be assembled into the encapsulated film without a binder, but an binder option can be considered assuming there is no interaction with molten Li and the proposed binder can be easily removed after Li wetting; ● Scale-up and / or production of coarse-grained carbon materials (such as films) from fine carbon particles, which can be achieved through processes such as tumbling, pressure compaction, thermal reaction, fusion, drying, agglomeration from liquid suspensions, and electrostatic processes to shape coin-sized structures into discs; ● Collect or screen any one of the aforementioned materials within the reactor; ● Microwave sintering or fusion after execution; and ● Partial pressing of discs or ingots is performed without relying on carbon molds.

[0373] The formation of intrinsic carbon particles used to form the few-layer graphene and other carbons in anode 1300 may include: ● Optimize sp2 and / or sp3 carbon structure formation to increase lithium insertion / intercalation; and ● Reduce contamination from impurities such as acetylene and other plasma-derived aromatic compounds.

[0374] Post-processing methods may include: ● Washing aromatic substances, such as removing aromatic substances; ● Bake the charcoal at approximately 500°C for about 3 hours to remove adsorbed moisture and / or oxygen; and ● Nitriding and / or treating carbon with silicon monoxide.

[0375] Factors influencing the carbon structure of Li-wetting anode 1300 may include precursor volume; melting temperature such as approximately 180°C to 380°C; particle post-treatment such as at the carbon surface exposed to Li; mechanical stress; graphene properties, few-layer or sheet size; carbon structure morphology including pore size, volume, and distribution; and surface activation.

[0376] The reaction of carbon structures to Li infiltration may include: spontaneous infiltration; accumulation of excess Li material to achieve a balance mass proportional to the Li input; and the degree of infiltration based on the ratio of the carbon surface area exposed to Li infiltration to the total volume of a control carbon structure.

[0377] Figure 14 shows a comparison of the specific capacity of silicon and carbon (Si-C) anodes in mAh / g over several charge-discharge cycles according to some embodiments. Various series shown, including 426, 459, 462, 486, 487, and 401, may include one or more similar variations and / or preparations of the anode 1300 shown in Figure 13 or the carbon structures shown in Figures 1A to 1F within a Li-ion or LiS system anode. As shown, the carbon structures disclosed in this invention can uniformly produce a specific capacity value significantly higher than the 372 mAh / g typically associated with graphite anodes.

[0378] Figures 15 and 16 show schematic diagrams relating to the ideal cathode assembly 1500 shown in Figure 15 according to some embodiments, characterized by the dispersion of lithium sulfide (Li₂S) nanoparticles in graphene sheets held together by a PAN-type adhesive and immersed in a LiTFSI electrolyte solution to facilitate Li ion transport and electrical conduction, and the reduction and control of polysulfides (PS) generated during the charge-discharge cycle of the Li₂S battery system. In the Li₂S battery system, the ideal cathode assembly 1500 can be implemented at least in part using any one or more of the carbon structures disclosed in this invention, which are included to form the pores 105E and / or interconnected microstructures 107E shown in Figure 1E.

[0379] Figure 16 illustrates an exemplary in-situ 3D nanostructured few-layer graphene material 1600, which may include structural definition for any one or more of the carbon structures disclosed in this invention. In some embodiments, the few-layer graphene sheet stack 1602 may comprise milled sulfur-impregnated graphene heated to 250°C and 350°C using a two-stage high-temperature (HT) process. The few-layer graphene sheet stack 1602 may be Li-wetted, such as by a THF solution containing lithium triethylborohydride (LiEt3BH) or by n-butyllithium provided as a Li source 1604 by means of any one or more of the aforementioned Li-wetting techniques, placed in an inert argon (Ar) atmosphere. The Li-wetted stack 1602 of few-layer graphene sheets can undergo HT vacuum treatment at 110°C for 10 hours to form Li2S in situ in pores, such as pore 105E shown in Figure 1E, wherein the Li2S participates in the operation of LiS electrochemical cells as previously described.

[0380] Figure 17A shows an enlarged perspective cross-sectional view of carbon-based particles 100A, 100E, and / or their analogues. As discussed in Figures 1A to 1E, individual links 1702A formed by the contact surfaces and / or regions between the conductive interconnect aggregates 101B of graphene sheets, as illustrated by the carbon-based particles 100A, can extend to form the lattice and / or dendritic branching structures of portions of 1700A. Li ions (Li+) 1704A can be sandwiched or inserted between the individual gradient layers of portions of 1700A within the 3D bundles 101B containing graphene sheets through these lattice and / or dendritic branching structures. Current can be generated via electron flow through the contact surfaces and / or regions between the interconnected 3D bundles 101B of graphene sheets. Li ions can flow through larger pores of about 20 to 50 nanometers with a pore or pore bimodal distribution as described in Figures 1A to 1E, or be confined to pores of generally about 1 to 3 nanometers in size, such as by chemical micron confinement.

[0381] Therefore, the Li ion flow can be finely controlled or tuned within the carbon-based particles 100A as needed, for example, to be diametrically opposite to the electron flow, to promote the electrochemical gradient necessary for electrical conduction and / or electron flow at the contact points and / or regions of the 3D bundle 101B of the graphene sheet. The spacing between individual carbon-based links can be set to 0.1 µm. Those skilled in the art will understand that, by way of example only, a size of 0.1 µm is provided, and other suitable similar or dissimilar sizes can exist in portions 1700A of the carbon-based particles 100A.

[0382] Parts of 1700A can be formed by sintering together graphene sheets to form 3D bundles 101B of graphene sheets in which there are no fully open channels that would allow electrical conduction through the contact points and / or regions of the interconnecting 3D bundles 101B of the graphene sheets. Therefore, the liquid and carbon-carbon bonding conductivity through the voids 1704A facilitates the bonding of carbon-based materials with other carbon-based materials where chemical adhesives and / or chemical bonding materials or reagents are unnecessary, as many of these chemical adhesives and / or chemical bonding materials or reagents produce undesirable chemical properties or side effects on the function of the carbon-based particles 100A.

[0383] The open porous scaffold 102A, composed of carbon-based particles 100A, deviates from conventional industrial standard battery electrode structures, which may involve slurry-cast boulders or relatively large particles randomly organized on a matrix. These boulders typically require binders to hold them together for electrical conduction. The open porous scaffold 102A, defined by the hierarchical pores 101A and / or interconnected microstructures 107E of the carbon-based particles 100A, allows for improved electrical conduction within it.

[0384] Figure 17B shows the carbon-based particles of Figure 17A with graphene-on-graphene densification. In the example of Figure 17B, the surfaces 1700B shown in Figure 17B and / or 1708A shown in Figure 17A at the edge regions can be densified by the application, deposition, or otherwise growth of multiple additional graphene layers. These edge regions are at least partially flat surfaces of the branched dendritic structure of portions 1700A of the carbon-based particles 100A. These densification processes and / or procedures allow for the creation of intricate, multilayered, and potentially virtually infinitely tunable 3D carbon structures comprising combinations of 3D bundles 101B of graphene sheets. Therefore, this fine tunability achieved through graphene-on-graphene densification facilitates the attainment of specific conductivity values ​​when the carbon-based particles 100 are integrated into battery electrode packs.

[0385] Figures 18A to 18C respectively show one or more of the carbon structures disclosed in this invention, including actual micrographs 1800A, 1800B and 1800C of carbon-based particles 100A and / or connected microstructures 107E shown in Figures 1A and 1E respectively.

[0386] Figure 18D shows a micrograph 1800D in which the composite carbon aggregate has an internal structure similar to that described for the carbon-dominant particles 100A, fully possessing pores 105E and interconnected microstructures 107E, and its size and composition have been prepared for incorporation into the cathode of a Li ion system, but it can also be used in the method to create a cage for Li on the anode. Aggregates with randomly sized and shaped aggregates can be used to manufacture any one or more of the electrodes disclosed in this invention. Nevertheless, the tuning process can allow the production of carbon aggregates and / or particles with regular, expected sizes, potentially providing ease of handling and processing advantages.

[0387] Figure 18E shows micrograph 1800E, in which an activated carbon structure is used to wet sulfur (S) for use in a LiS system cathode, including at least one or more of the carbon-based structures disclosed in this invention, including the interconnected microstructure 107E shown in Figure 1E. The activated carbon structure for wetting sulfur (S) shown in micrograph 1800E can be produced by incorporating a helical conveyor system or via other different steps. The material produced by the thermal reactor has been shown to be more lithium-friendly than undoped and / or unfunctionalized microwave-generated carbon structures. In some embodiments, the prevalence of organic and / or hydrocarbon-based contamination on the few-layer graphene surface produced in the reactor may require additional post-treatment improvement steps.

[0388] Figure 19A shows a schematic depiction 1900A of a 3D graphene-particle cathode scaffold such as carbon scaffold 300B, characterized in that it is suitable for scaling up the sulfur (S) micron confinement therein and / or any one or more of the carbon disclosed in this invention, including the forming material used to produce the interconnected microstructure 107E shown in Figure 1E. In the examples of Figure 19A, graphene-based sheets and / or structures containing sulfur entrainment and / or confinement 1902A are shown in various 3D cathode scaffold types or configurations having various thicknesses 1904A and 1906A. S includes providing the required charge storage and residence in graphene-based battery chemistry, which is measured in milliampere-hours and is further described by the synthesis of graphene-sulfur composite materials using lightly oxidized graphene oxide sheets decorated with carbon black nanoparticles to coat submicron sulfur particles coated with polyethylene glycol (PEG).

[0389] PEG and graphene coatings are important for accommodating the volume expansion of coated sulfur particles during discharge, trapping soluble polysulfide intermediates, and enabling the sulfur particles to conduct electricity. The resulting graphene-sulfur composite showed performance exceeding 100 cycles at most... A high and stable specific capacity of 600 mAh / g indicates its potential as a cathode material for rechargeable Li-ion battery packs with high energy density. Other studies have shown that activated graphene (AG) with various specific surface areas, pore volumes, and average pore sizes has been fabricated and used as a sulfur matrix. The effects of AG pore structure parameters and sulfur loading on the electrochemical performance of Li-sulfur battery packs were systematically investigated.

[0390] The results showed that the specific capacity, cycle performance, and coulombic efficiency of the battery pack were closely related to the pore structure and sulfur loading. The AG3-sized (S) composite electrode with a high sulfur loading of 72 wt.% exhibited excellent long-term cycling stability with 50% capacity retention and an ultra-low capacity decay rate (0.05% / cycle) within 1,000 cycles. Furthermore, when LiNO3 was used as the electrolyte additive, the AG3 / S electrode exhibited similar capacity retention and high coulombic efficiency within 1,000 cycles at ~98%. The excellent electrochemical performance of the AG3 / S electrode series is attributed to the mixed microporous / mesoporous structure, high surface area, and the good conductivity of the AG matrix and well-distributed sulfur within the micropores / mesopores, which is beneficial for electrical and ion transfer during cycling.

[0391] Figure 19B shows 3D few-layer graphene anode supports, such as carbon supports 300 and / or lithium-ion carbon supports 400A, prepared and used in or as a forming material for a Li-ion or LiS system anode with Li interlayers between graphene layers. In the example of Figure 19B, Li ions (Li+) are shown in various configurations 1900B, including 1902B sandwiched into FLG and 1904B in which Li metal is reversibly included in a carbon-based host support. The Li interlayers in bilayer graphene can address and solve the following problems in the field of Li-ion battery packs: the true capacity of graphene and the method of Li storage in graphite.

[0392] Theoretical calculations confirm that various physiological and chemical characterizations of segmented lithium bilayer graphene products further reveal regular Li intercalation, thus fully illustrating this fundamental two-dimensional lithium storage mode. These findings not only enable commercial graphite as the first electrode with a clear lithium storage approach but also guide the development of graphene materials in Li-ion battery packs. Li absorption and intercalation in monolayer and few-layer graphene differ from those associated with bulk graphite. For monolayer graphene, cluster amplification methods were used to systematically explore the lowest-energy ion arrangement varying with the absorbed Li content. It was predicted that unless the monolayer graphene surface contains defects, there is no Li arrangement that stabilizes Li absorption on that surface. Based on these results, it was concluded that defect-poor monolayer graphene exhibits significantly worse capacity compared to bulk graphite.

[0393] In some implementations, in addition to one or more of the sacrificial membrane substrate and the supporting membrane substrate, the carbon-based particle membrane may include at least the following particle properties: tunable velocity of the substrate; tunable impact energy from implantation to adsorption; tunable thickness; and tunable porosity; and one or more of the above properties may be integrated with additional manufacturing capabilities.

[0394] In some embodiments, as substantially discussed in conjunction with the elements shown in Figures 1A to 1E, any or more of the carbon and carbon-based structures disclosed in this invention can enable significant battery pack performance advantages over currently available Li-ion and / or LiS battery packs, including: achieving any or more of the physical and / or electrical energy storage and / or conductivity values ​​of sulfur and / or sulfur-intercalated cathode states, and graphene sheets 102A and / or conductive carbon particle states dispersed therewith to define pores and / or voids, in the case of intercalated Li (Li+) ions, ultimately achieving an energy density storage value of 900 to 2,000 (mAh) / g.

[0395] Figure 20A shows the cathode specific capacity level during cycling and the application and / or use of various representative sulfur nanoscale limitations, as well as their derived diagrams and images, as a system based on or using carbon-based particles 100A. Modified cathode specific capacity and electrode levels, as measured in mAh / g, for various compositions and / or compounds are shown in Figure 2008a. Any or more of these compositions and / or compounds at least partially include carbon-based particles 100A formed therewith and integrated with them to enhance the cathode specific capacity.

[0396] Figures 20B and 20C show graphs on accelerated carbon tuning for reducing polysulfide (PS) shuttle-related problems. These graphs indicate that increasing the porosity of carbon-based materials, carbon-based particles 100A, and their variations reduces PS shuttle, defined as the undesirable self-discharge of the autoelectrochemical battery resulting from sulfur (S) reaching the negative electrode surface and undergoing chemical reduction. Graph 2002B in Figure 20B shows the average intensity change of low-porosity carbon, which is generally at a higher level than high-porosity carbon. Graph 2002C in Figure 20C shows high-porosity carbon, which generally has a higher percentage of capacity retention during repeated battery pack use cycles compared to low-porosity carbon.

[0397] Tuning carbon-based particles 100A can achieve more efficient manufacturing, including: increased Li utilization and the potential increase in the ratio of active to inactive materials within the battery pack electrodes; binder reduction; improved uniformity; and controlled electrochemical reactions, such as battery pack conductivity and / or activity. The parameters of carbon-based particles 100A can be tuned to achieve specific performance characteristics that vary with the Li loading percentage / unit area or volume of carbon-based particles 100A, including: ● At low loading levels below capacity, compensation for first charge loss / more efficient SEI formation; at saturation / matched loading levels, current coupling to the Li-rich region of carbon. ● When in contact with an electrolyte and Li and / or Li ions are inserted through the spaces between graphene layers, the oxidizing material; ● Metallic Li is infiltrated into an engineered carbon matrix at an excess loading level; the matrix is ​​configured to accommodate / stabilize Li amplification and suppress dendritic crystal formation caused by increased Li surface area, resulting in a specific capacity comparable to pure Li: > 2,000 mAh / g; and ● A process / methodology for preparing Li ions that can be directly transferred to lithium-ion hybrid capacitors.

[0398] As outlined in Listing 2900E, ongoing challenges related to the thermal and / or liquid infusion of Li and / or Li ions into carbon-based structures such as carbon-based particles 100A may include management of surface tension and wettability of Li reactivity at the solid-liquid electrolyte interface; management of capillary Li and / or S wetting kinetics; engineering of electrical gradients through electrode thickness; gradation of the transition to higher ion conductivity concentrations and / or levels at the current collector and to the electrolyte interface; and carefully tuned engineering of surface chemistry to promote stable SEI formation in contact with the electrolyte and minimize reactivity with air.

[0399] The revealed state can be constructed on the basis of a conventional two-dimensional (2D) plating, similar to the brightener used in electroplating. In electroplating, the addition of chemical additives can often increase polarization and decrease current density; such as redirecting the current density to a low region relative to a high region, such as a protrusion; producing a relatively high nucleation rate and a moderate charge transfer rate. In the case of plating or stripping for battery pack charging and discharging cycles, for battery packs equipped with electrodes with carbon-based particles 100A as shown in Figures 1A to 1E, the carbon film can act as a flexible carrier for SEI formation and redirecting the current density to a low region relative to a high region.

[0400] In the context of generating carbon-based particles 100A and integrating them with a Li-ion battery pack, bonding can be used in any one or more of the disclosed manufacturing techniques. Bonding refers to a method of altering a metal by heating it in contact with a powdered solid; precipitation in copper formation may refer to and / or involve heterogeneous methods. Such methods may refer to conditions where the reactants are two or more phases such as solid and gas, solid and liquid, or components of two immiscible liquids; or where one or more reactants undergo chemical changes at the interface or on the surface of a solid catalyst; where ions are reduced to zero valence at the surface of a solid metal, such as Cu ions on the surface of Fe particles; and where iron is oxidized and copper is reduced, as is the case with Li versus C, where copper has a relatively high current series.

[0401] The welding of molten metals, including Li metal, can be managed to enable any one or more of the aforementioned techniques to be functionally integrated with carbon-based particles 100A and / or used to generate carbon-based particles 100A to enhance the performance of Li-ion or LiS battery packs. These auxiliary methods and / or techniques include: reactive metal management via welding; and the use of inert shielding gases via liquid metal methods, such as classical metal inert gas (MIG), gas tungsten arc welding (GTAW), also known as tungsten inert gas (TIG), and submerged arc welding (SAW) to join reactive metals such as Ti and Al by welding. Examples include using inert shielding gases to form liquid pools of reactive metals in the absence of oxidation, where the ΔGf of oxides such as TiO2 and Al2O3 is at the same level as that of Li2O. In the presence of reactive liquid metals, oxygen and humidity can be effectively managed by the controlled use of inert shielding gases around the reactive metals. In such environments and conditions, liquid Li can be impregnated into the carbon-based structure of carbon-based particles 100A via controlled shielding gas assembly and operation.

[0402] Figure 21 shows the Raman spectrum of 3D N-doped FL graphene, including the initial carbon and N-doped carbon maps. In the example of Figure 21, the Raman spectrum of 3D N-doped FL graphene 2100 includes a 2D peak 2102 at approximately 2730 cm⁻¹ and D peaks 2104 and 2106 at approximately 1600 cm⁻¹ and 1400 cm⁻¹, respectively.

[0403] Figure 22 shows various properties associated with bilayer graphene 2200. In the example of Figure 22, the sample bilayer graphene basic structure 2200 is shown as having two layers of graphene oriented at the indicated location, which is understood to be a device containing only one, two, or three atomic layers. Schematic diagram 2202 shows approximate spacing measurements of 1.42 Å, 1.94 Å, and / or 3.35 Å between individual graphene sheets. Schematic diagram 2204 shows various exemplary defect sites 2206 and / or 2208 that may exist in the defined adjacent region of the edge plane and / or be supplemented by one or more graphene sheets including carbon-dominant particle structures. Schematic diagram 2210 shows various model diagrams 2212 of the top view of the hard spherical carbon particle model.

[0404] In some embodiments, reactor tuning can be performed to, for example, perform one or more of the following: increase the spacing between FL graphene sheets, decrease van der Waals forces, control doping, promote carbon vacancy formation, and reduce Li adsorption energy and / or increase Li capacity. The Li ion interlocks can, for example, shift the graphene sheet stack from AB to A by adapting the interlocks with increased spacing, wherein, for example in graphite, AA can shift back to AB with the interlocks removed; and in FL graphene, the AA stack is retained, for example, by maintaining the increased spacing, with the interlocks removed. These stack arrangements can be associated with carbon-dominant particles 100A shown in Figures 1A to 1E.

[0405] Figure 23 shows an exemplary flow chart depicting an exemplary operation 2300 for preparing a 3D scaffolded membrane containing carbon-dominant particles. In the example of Figure 23, method 3300 includes preparing a 3D scaffolded membrane containing carbon-dominant particles in operation 2304 by providing the 3D scaffolded membrane to a roll-to-roll processing apparatus or device in operation 2306. A carbon-rich electrode can be deposited on the 3D scaffolded membrane in operation 2308; and processing of the 3D scaffolded membrane in the roll-to-roll processing apparatus or device, independent of the application of a chemically inactive binder, can occur in operation 2310 before the end of method 2300 in operation 2312.

[0406] The disclosure has been described with reference to specific examples in the foregoing specification. However, it is obvious that various modifications and changes can be made to it without departing from the broader spirit and scope of the disclosure. For example, the processing flow described above is described with reference to a specific order of method actions. However, the order of many described method actions can be changed without affecting the scope or operation of the disclosure. This specification and drawings should be regarded in an illustrative sense rather than a restrictive sense.

[0407] The various implementation schemes of this disclosure relate to the following numbered items: 1. A battery pack comprising: One cathode; An anode, positioned opposite the cathode, the anode including a mixed artificial solid-electrolyte intermediate phase (A-SEI) layer encapsulating the anode, the mixed A-SEI layer comprising: First active component; A second active component, which is disposed on the first active component; and Multiple carbon-containing aggregates, interwoven throughout the first and second active components and arranged to suppress the growth of Li dendrites from the anode toward the cathode; and A spacer is located between the anode and the cathode. 2. The battery pack of Clause 1, wherein the cathode comprises a porous, carbon-based structure, which is configured to expand in the presence of polysulfide (PS) shuttles in one or more portions of the battery pack. 3. The battery pack of paragraph 1 further includes an electrolyte dispersed between the anode and the cathode and in contact with the anode and the cathode. 4. The battery pack of paragraph 3, wherein the plurality of carbon-containing aggregates comprise a polymer, the polymer comprising a cross-linked polymeric network. 5. The battery pack of item 4, wherein the cross-linked polymeric network is configured to control the amount of contact between the electrolyte and the anode. 6. The battery pack of item 4, wherein a first portion of the cross-linked polymeric network has a first cross-linking density, and a second portion of the cross-linked polymeric network has a second low cross-linking density different from the first cross-linking density. 7. The battery pack of item 4 further includes a gradient defined by a crosslinking density of the crosslinked polymeric network that spans the hybrid A-SEI layer encapsulating the anode. 8. The battery pack of paragraph 4, wherein the cross-linked polymeric network comprises one or more of a monomer or an oligomer. 9. The battery pack of item 4, wherein the cross-linked polymeric network is configured to inhibit the dissolution of the mixed A-SEI layer. 10. The battery pack of item 4, wherein the cross-linked polymeric network has Li wettability configured to promote Li adhesion to the cross-linked polymeric network. 11. The battery pack of paragraph 4, wherein the cross-linked polymeric network comprises any or more of a vinyl group, an acrylate group, a methacrylate group, or an epoxy group. 12. The battery pack of Clause 11, wherein any or more of the vinyl, acrylate or methacrylate groups are combined for curing by any or more of an ultraviolet (UV) curing method or a thermosetting method. 13. The battery pack of Clause 11, wherein the epoxy-based group is configured to be cured by adding an amine group or a amide group. 14. The battery pack of clause 1, wherein the first active component includes a barrier. 15. The battery pack of clause 14, wherein the barrier is configured to prevent direct contact between the Li metal in the anode and the electrolyte. 16. The battery pack of paragraph 14 further includes a naturally occurring solid-electrolyte interface (SEI), wherein the barrier is configured to prevent the formation of an instability in the naturally occurring SEI. 17. The battery pack of clause 14, wherein the barrier is configured to prevent the electrolyte from decomposing. 18. The battery pack of item 1 further includes a Li layer deposited on the second active component. 19. The battery pack of clause 18, wherein the second active component is assembled to ensure uniform deposition of one of the Li layers. 20. The battery pack of paragraph 1, wherein the spacer is configured to transport Li ions from the anode to the cathode via the spacer. 21. The battery pack of clause 20, wherein the spacer is further configured to suppress the growth of the Li dendrites from the anode toward the cathode. 22. The battery pack of clause 1, wherein the anode further comprises a conductive substrate configured to support the hybrid A-SEI layer. 23. The battery pack of clause 22, wherein the conductive substrate includes a copper current collector. 24. The battery pack of item 1, wherein the anode comprises a metal foil. 25. The battery pack of item 24, wherein one of the metal foils has a thickness of approximately between 1 µm and 250 µm. 26. The battery pack of paragraph 25, wherein the metal foil comprises a Li layer with a thickness of about 15 µm to 50 µm. 27. The battery pack of Clause 1, wherein the hybrid A-SEI layer comprises a component comprising a plurality of carbon nano-onions (CNO), wherein the component is conductive. 28. A battery pack as described in clause 1, wherein the hybrid A-SEI layer is configured to electrochemically stabilize itself during the operational cycling of the battery pack. 29. The battery pack of paragraph 1, wherein the hybrid A-SEI layer may include one or more flexure points configured to cyclically expand and contract a volume of the hybrid A-SEI layer during the operational cycles of the battery pack. 30. The battery pack of clause 1, wherein at least one of the first active component or the second active component includes a passivation layer. 31. The battery pack of clause 30, wherein the passivation layer comprises an inorganic component. 32. The battery pack of clause 31, wherein the inorganic component comprises one or more of the following: Al2O3, LiF, Li2S6, P2S5, Li3N, SiO2, MoS2, Li2S3, LiF, LiN3, Li-metal alloy, Li-Si, Li3PO4, LiI or Li3PS4. 33. The battery pack of clause 30, wherein the passivation layer comprises one or more metal crosslinked carboxylates, the one or more metal crosslinked carboxylates comprising the acrylate group of Zn, Sn, Sr, In, Al or Mo, the methacrylate group or higher crosslinking analogues. 34. The battery pack of paragraph 1, wherein the plurality of carbon aggregates define a porous structure comprising a plurality of few-layer graphene (FLG) sheets fused together. 35. A battery pack comprising: One cathode; An anode, which is positioned relative to the cathode; A hybrid artificial solid-electrolyte intermediate phase (A-SEI) layer is deposited on the anode and includes multiple active components; A doping material, interwoven throughout the plurality of active components and configured to suppress the growth of lithium (Li) dendrites from the anode to the cathode, the doping material comprising: A combination of a crystalline sp2-bonded carbon domain of a graphene sheet and one of a plurality of flexible wrinkled regions located at two or more connection points within the crystalline sp2-bonded carbon domain of the graphene sheet; and A polymer matrix, which is configured to bond the plurality of active components together with the blending material; An electrolyte, which is in contact with the mixed A-SEI and the cathode; and A spacer is located between the anode and the cathode. 36. The battery pack of clause 35, wherein the admixture comprises any or more curable metal carboxylates, the any or more curable metal carboxylates comprising one or more of the following: acrylates, methacrylates or more advanced curable carboxylates of zinc, strontium, tin, indium, aluminum or molybdenum. 37. The battery pack of clause 35, wherein the pack further comprises one or more flexure points configured to shrink one volume of the A-SEI layer during crosslinking of the polymer matrix. 38. A battery pack as described in clause 35, wherein the cathode comprises a porous structure that is configured to expand in the presence of polysulfide (PS) shuttles in one or more portions of the battery pack. 39. The battery pack of clause 35, wherein the plurality of active components comprises: A first active component; and A second active component is disposed on the first component. 40. The battery pack of clause 39, wherein at least one of the first active component or the second active component includes a passivation layer. 41. The battery pack of clause 40, wherein the passivation layer comprises an inorganic component. 42. The battery pack of clause 41, wherein the inorganic component comprises one or more of the following: Al2O3, LiF, Li2S6, P2S5, Li3N, SiO2, MoS2, Li2S3, LiF, LiN3, Li-metal alloy, Li-Si, Li3PO4, LiI or Li3PS4. 43. The battery pack of paragraph 39, wherein the first component includes a barrier configured to prevent direct contact between the Li metal in the anode and the electrolyte. 44. The battery pack of paragraph 43 further includes a naturally occurring solid-electrolyte interface (SEI) formed between the anode and the electrolyte, wherein the barrier is configured to prevent the formation of an unstable component of the naturally occurring SEI. 45. The battery pack of paragraph 43, wherein the barrier is configured to prevent the electrolyte from decomposing. 46. ​​The battery pack of paragraph 39 further comprises a Li layer deposited on the anode. 47. The battery pack of clause 46, wherein the second active component is assembled to ensure uniform deposition of one of the Li layers on the anode. 48. The battery pack of clause 35, wherein the spacer is configured to transport Li ions from the anode to the cathode via the spacer. 49. The battery pack of clause 35, wherein the spacer is configured to suppress the growth of the Li dendrites from the anode toward the cathode. 50. The battery pack of clause 35, wherein the anode further comprises a conductive substrate configured to support the hybrid A-SEI layer. 51. The battery pack of clause 50, wherein the conductive substrate includes a copper current collector. 52. The battery pack of clause 35, wherein the anode comprises a metal foil. 53. The battery pack of clause 52, wherein one of the metal foils has a thickness of approximately between 1 µm and 250 µm. 54. The battery pack of paragraph 53, wherein the metal foil comprises a Li layer with a thickness of about 15 µm to 50 µm. 55. The battery pack of clause 35, wherein the hybrid A-SEI layer is ionically conductive and configured to preferentially conduct electricity after the addition of conductive carbon. 56. A battery pack as described in clause 35, wherein the hybrid A-SEI layer is configured to electrochemically stabilize itself during the operational cycling of the battery pack. 57. The battery pack of clause 35, wherein the polymer matrix comprises one or more of the following: cross-linked polydimethylsiloxane (PDMS), polystyrene (PS), bis(2-(methacryloxy)ethyl) phosphate, a binder primarily composed of 2-hydroxyethyl methacrylate, including one or more of succinate, maleate, phthalate, or phosphate, glyceryl dimethacrylate maleate, polyethylene glycol (PEO), poly(3,4-ethylenedioxythiophene) (PEDOT), styrene-butadiene rubber (SBR), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), and polyvinylidene fluoride (PVDF). 58. The battery pack of clause 35, wherein the polymer matrix comprises a cross-linked polymeric network configured to control a contact amount between the electrolyte and the anode. 59. The battery pack of clause 58, wherein a first portion of the crosslinked polymeric network has a first crosslinking density, and a second portion of the crosslinked polymeric network has a second low crosslinking density different from the first crosslinking density. 60. The battery pack of clause 58 further includes a gradient defined by a crosslinking density of the crosslinked polymeric network spanning the hybrid A-SEI layer encapsulating the anode. 61. The battery pack of paragraph 58, wherein the cross-linked polymeric network comprises one or more of a monomer or an oligomer. 62. The battery pack of item 58, wherein the cross-linked polymeric network is configured to inhibit the dissolution of the mixed A-SEI layer. 63. The battery pack of clause 58, wherein the cross-linked polymeric network has a defined Li wettability associated with Li adhesion to the cross-linked polymeric network. 64. The battery pack of Clause 58, wherein the cross-linked polymeric network comprises any or more of a vinyl group, an acrylate group, a methacrylate group, or an epoxy group. 65. The battery pack of clause 64, wherein any or more of the vinyl, acrylate or methacrylate groups are combined for curing by any or more of an ultraviolet (UV) curing method or a thermosetting method. 66. The battery pack of clause 64, wherein the epoxy-based group is configured to be cured by adding an amine group or a amide group. 67. The battery pack of paragraph 35, wherein the pack further comprises a plurality of three-dimensional (3D) carbon-based aggregates, each 3D ...

Claims

1. A battery pack comprising: a cathode; an anode positioned opposite the cathode, the anode including a mixed artificial solid-electrolyte mesophase (A-SEI) layer encapsulating the anode, the mixed A-SEI layer including: a first active component; a second active component disposed on the first active component; and a plurality of carbon-containing aggregates interwoven throughout the first active component and the second active component and configured to inhibit the growth of Li dendrites from the anode toward the cathode; and a spacer located between the anode and the cathode, wherein the battery pack further includes an electrolyte dispersed between the anode and the cathode and in contact with the anode and the cathode, wherein the plurality of carbon-containing aggregates include a polymer including a crosslinked polymeric network, and wherein the battery pack further includes a gradient defined by a crosslinking density of the crosslinked polymeric network spanning the mixed A-SEI layer encapsulating the anode.

2. The battery pack of claim 1, wherein the cathode comprises a porous, carbon-based structure, which is configured to expand in the presence of polysulfide (PS) shuttles in one or more portions of the battery pack.

3. The battery pack of claim 1, wherein the cross-linked polymeric network is configured to control a contact amount between the electrolyte and the anode.

4. The battery pack of claim 1, wherein a first portion of the crosslinked polymeric network has a first crosslinking density, and a second portion of the crosslinked polymeric network has a second low crosslinking density different from the first crosslinking density.

5. A battery pack comprising: a cathode; an anode positioned opposite the cathode; a mixed artificial solid-electrolyte mesophase (A-SEI) layer deposited on the anode and including a plurality of active components; a dopant material interwoven throughout the plurality of active components and configured to inhibit the growth of lithium (Li) dendrites from the anode to the cathode, the dopant material comprising: a combination of crystalline sp2-bound carbon domains of graphene sheets and one of a plurality of flexible wrinkled regions located at two or more connection points of the crystalline sp2-bound carbon domains of the graphene sheets; and a polymer matrix configured to bond the plurality of active components to the dopant material; an electrolyte in contact with the mixed A-SEI and the cathode; and a spacer located between the anode and the cathode, wherein the combination further includes one or more flexure points configured to shrink a volume of the A-SEI layer during crosslinking of the polymer matrix.

6. The battery pack of claim 5, wherein the admixture comprises any or more curable metal carboxylates, the any or more curable metal carboxylates comprising one or more of the following: acrylates, methacrylates or more advanced curable carboxylates of zinc, strontium, tin, indium, aluminum or molybdenum.

7. The battery pack of claim 5, wherein the cathode comprises a porous structure that is configured to expand in the presence of polysulfide (PS) shuttles in one or more portions of the battery pack.

8. The battery pack of claim 5, wherein the plurality of active components comprises: a first active component; and a second active component disposed on the first active component.

9. The battery pack of claim 8, wherein at least one of the first active component or the second active component includes a passivation layer.

10. The battery pack of claim 9, wherein the passivation layer comprises an inorganic component.

11. A method for manufacturing a lithium (Li) anode, the method comprising: forming a slurry by mixing a plurality of electrically insulating sheet-like carbons and a plurality of carbon nanotubes (CNO); casting the slurry onto a release film; drying the slurry; and transferring the dried slurry on the release film onto a lithium sheath copper foil of the Li anode by roll lamination.

12. The method of claim 11, wherein the roll lamination comprises: applying pressure to the dry slurry on the release film; forming a protective carbon-containing layer based on the pressure applied to the dry slurry on the release film; rolling the protective carbon-containing layer onto the Li anode; and releasing the release film from the protective carbon-containing layer while maintaining adhesion between the carbon-containing layer and the Li anode.

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