Advanced Lithium (LI) Ion and Lithium Sulfur (LIS) Batteries

Abstract

The present invention provides a lithium (Li) ion battery comprising an anode, a cathode positioned opposite the anode, a porous separator positioned between the anode and the cathode, and a liquid electrolyte in contact with the anode and the cathode. The anode comprises an electrically conductive substrate. A first film is deposited on the electrically conductive substrate. The first film comprises carbon particles of a first concentration that are in contact with one another and define a first electrical conductivity for the first film. Each carbon particle comprises a plurality of aggregates formed of a few-layer graphene sheet. The plurality of aggregates form a porous structure configured to undergo lithiation, which may include any one or more of an intercalation operation or a plating operation. The anode and the cathode may comprise an electroactive material. The porous structure may provide conduction between the few-layer graphene sheets.

Description

Technology Field

[0001] The present disclosure generally relates to the production of carbon-based particles, and more specifically to the incorporation of the produced carbon-based particles into a battery electrode. Background Technology

[0002] Technological advancements have enabled consumers to use electronic devices in many new applications that were previously impossible. These devices have already become commonplace, and many of them rely on battery power, with their popularity continuing to grow. To meet the related power consumption demands, batteries, particularly secondary batteries such as rechargeable batteries, have emerged as a universal solution by allowing for portability and convenient, continuous device use.

[0003] The ongoing challenges regarding rechargeable battery performance, particularly concerning both lifespan and cyclability, have therefore driven continuous innovation in the technology known as lithium-ion, or Li-ion. Typically, intercalated Li compounds can be used as the forming material at the cathode, paired with graphite at the anode. Unlike other battery types, lithium-ion batteries have been sought for use in portable electronic devices due to their relatively high energy density and are limited by the absence of memory effects, such as those occurring in conventional nickel-cadmium and nickel-metal hydride rechargeable batteries, which lose the ability to store charge over numerous charge-discharge cycles involving partial discharge and relatively low self-discharge. Consequently, lithium-ion batteries offer many of the advantages found in primary, for example, non-rechargeable Li batteries, including high charge density that results in a longer effective lifespan without concerns regarding rapid discharge, which can cause overheating, rupture, or explosion in lithium batteries due to the high reactivity of lithium metal.

[0004] To support advancements in Li-ion battery capacity, cycleability, and power transfer, amorphous carbon has been considered alongside Li as a forming material for Li-ion battery electrodes. However, these electrodes continue to suffer from relatively low electrical conductivity and high charge transfer resistance, which leads to high polarization or internal power loss. Among other potential problems, existing amorphous carbon-based cathode materials tend to produce high irreversible capacity. means of solving the problem

[0005] This summary is provided to introduce, in a simplified form, the selection of concepts further explained in the detailed description below. This summary is not intended to identify the primary or essential functions of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter.

[0006] One innovative aspect of the subject matter described in this disclosure may be realized as a lithium (Li) ion battery comprising an anode, a cathode positioned opposite the anode, a porous separator positioned between the anode and the cathode, and a liquid electrolyte in contact with the anode and the cathode. The anode comprises an electrically conductive substrate. A first film is deposited on the electrically conductive substrate. The first film comprises carbon particles of a first concentration configured to define a first electrical conductivity for the first films in contact with one another. Each carbon particle comprises a plurality of aggregates formed of a few-layer graphene sheet. The plurality of aggregates forming a porous structure are configured to undergo lithiation.

[0007] Lithium-lithiation may include any one or more of intercalation operations or plating operations. The anode and cathode may each include an electroactive material. The porous structure is configured to provide electrical conductivity between the contacts of the few-layer graphene sheets. The porous structure may be configured to contain molten Li metal. The porous structure may be configured to accommodate a liquid electrolyte that may be configured to facilitate the transport of multiple Li ions within the porous structure.

[0008] A second film may be deposited on a first film. The second film may contain carbon-based particles of a second concentration. The carbon-based particles of the second concentration are configured to provide a second electrical conductivity for the second film that is lower than the first electrical conductivity. An electroactive material may be present in the pores of one or both of the anode and the cathode. The electroactive material is approximately 1,635 m 2 / g to 2,675m 2 It may have a specific surface area (SSA) of / g. The electroactive material may comprise any one or more of pre-lithiated few-layer graphene (FLG) sheets, pristine graphene, graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, nitrified graphene, boron-doped graphene, nitrogen-doped graphene, chemically functionalized graphene, physically or chemically activated or etched versions thereof, sulfur-doped graphene, or electrically conductive polymer-coated or grafted versions thereof.

[0009] The porous structure may be defined by an aggregate independent of the binder and may be configured to be formed substantially spherically having any one or more dimensions in the range of 1 to 30 μm, < 50 μm, or greater than 500 nm. The porous structure may include an active Li intercalating structure configured to incorporate silicon (Si). The active Li intercalating structure may have a specific capacity between approximately 730 and 3,600 mAh / g. The chemically functionalized graphene may include functional groups selected from combinations thereof comprising functional groups configured to react with or include any one or more of quinone, hydroquinone, quaternary aromatic amine, mercaptan, disulfide, sulfonate (-SO3), transition metal oxide, transition metal sulfide, or magnesium (Mg), calcium (Ca), aluminum (Al), strontium (Sn), and zinc (Zn).

[0010] The electrically conductive substrate may be a current collector, which may be at least partially foam-based or foam-derived, and is selected from any one or more of metal foam, metal web, metal screen, perforated metal, sheet-based 3D structure, metal fiber mat, metal nanowire mat, electrically conductive polymer nanofiber mat, electrically conductive polymer foam, electrically conductive polymer coated fiber foam, carbon foam, graphite foam, carbon aerogel, carbon zerogel, graphene foam, graphene oxide foam, reduced graphene oxide foam, carbon fiber foam, graphite fiber foam, and exfoliated graphite foam.

[0011] The current collector may be formed as a foil. The electroactive material may include one or more of nanoparticles, nanodiscs, nanoplates, nanocoatings, or nanosheets of inorganic materials. The nanoparticles, nanodiscs, nanoplates, nanocoatings, or nanosheets of inorganic materials may be selected from bismuth selenide or bismuth telluride, transition metal dichalcogenides or trichalcogenides, sulfides, selenides, or transition metal tellurides, boron nitride, or combinations thereof, and the nanoparticles, nanodiscs, nanoplates, nanocoatings, or nanosheets have a thickness of less than 100 nm.

[0012] Another innovative aspect of the subject matter described in this disclosure may be realized as an electrochemical cell electrode comprising a film layer deposited on an electrically conductive substrate. The film layer comprises an aggregate of carbon of any concentration formed from a plurality of few-layer graphene sheets fused together orthogonally, and a porous structure defined by the plurality of few-layer graphene sheets. The porous structure is composed of any one or more of providing electrical conductivity between contacts between any two or more of the plurality of few-layer graphene sheets or hosting an electroactive material.

[0013] One or more adjacent pairs of graphene sheets among a plurality of few-layer graphene sheets may comprise a first graphene sheet and a second graphene sheet separated by a D-spacing of 3 Å to 20 Å. The electrochemical cell electrode may comprise an anode, and the electroactive material comprises elemental lithium (Li) interspersed in the D-spacing of the anode. A plurality of Li ions are provided by elemental Li.

[0014] An additional film is deposited on the film. The film is configured to provide a first electrical conductivity, and the additional film is configured to provide a second electrical conductivity different from the first electrical conductivity.

[0015] The porous structure may include a plurality of interconnected channels configured to allow the liquid electrolyte to penetrate. Both the first electrical conductivity and the second electrical conductivity may be directly proportional to the migration of a plurality of Li ions provided by the electroactive material in the liquid electrolyte. The migration may be directed toward an additional electrochemical cell electrode positioned substantially opposite to the electrochemical cell electrode. The plurality of interconnected channels may be configured to prevent the accumulation of Li ions on any one or more of the electrochemical cell electrode or the additional electrochemical cell electrode.

[0016] The porous structure may include any one or more of intermediate-scale structuring or micron-scale fractal structuring. The electroactive material may include molten Li metal that can be configured to be injected into the porous structure.

[0017] The porous structure may be configured to be permeated by an electrolyte that may be configured to transport Li ions. The porous structure may be configured to be permeated by an electrolyte in any one or more of a liquid phase or a gel phase. The electrolyte may be any one or more of a polymer phase or a substantially solid electrolyte interphase that may contain a solid-state electrolyte, which is configured to at least substantially prevent or mitigate any one or more of the formation of Li dendrites, the formation of a short circuit, or leakage of the solid-state electrolyte.

[0018] The solid-state electrolyte may be selected from any one or more of a solid polymer electrolyte, a gel polymer electrolyte, or a non-polymer electrolyte. The solid-state electrolyte further comprises a Li salt dissolved in a polymer host, and the polymer host may comprise any one or more of polyethylene glycol (PEO), polyvinylidene fluoride or polyvinylidene difluoride (PVDF), poly(p-phenylene oxide) (PPO) or poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), poly(methyl methacrylate) (PMMA), polystyrene sulfonate (PSS) and salts of these polymers (Li or Na salts), PAN, and PANI.

[0019] Substantially, the solid electrolyte interface phase may comprise either a liquid component trapped in a polymer matrix or a non-polymer solid electrolyte. The liquid component is configured to facilitate Li ion transport. The non-polymer solid electrolyte is substantially a ceramic material or a Li superion conductor (LISICON), garnet-type Li7La3Zr2O 12 It may include any one or more of a ceramic nanofiber-incorporated composite including (LLZO), and a calcium titanium oxide mineral composed of calcium titanate including perovskite. The non-polymer solid electrolyte may have a thickness in the range of approximately 0.5 µm to 40 µm. The thickness may be configured to substantially prevent any one or more of the formation or growth of Li dendrites.

[0020] The porous channel structure may include a first part configured to provide a Li ion conduit, a second part configured to facilitate rapid Li ion transport, and a third part configured to confine an electroactive material. The electrical conductivity is in the range of about 1,000 S / m to about 20,000 S / m.

[0021] One or more additional film layers may be deposited on the film layer, and any one or more of them are configured to provide electrical conductivity that is proportionally reduced to that of the film layer immediately preceding it in a direction substantially orthogonal to the electrically conductive substrate.

[0022] A solid-electrolyte interface (SEI) may be formed near the porous structure. The electrochemical cell may additionally include an artificial solid-electrolyte interface (ASEI) located near the porous structure. The ASEI is formed in situ during the formation of the porous structure or ex situ through any one or more of a coating, film, or reactant.

[0023] The porous structure may include one or more lithium-affinity functionalized surfaces that can be configured to provide Li adsorption centers.

[0024] One innovative aspect of the subject matter described in the present disclosure may be implemented as a method for manufacturing an anode. The method may include the steps of nucleating a plurality of carbon particles at a first concentration level, forming a first film on a sacrificial substrate based on the first concentration level, - each carbon particle is defined by a plurality of aggregates formed of a few-layer graphene sheet fused together -, defining a porous structure based on the few-layer graphene sheet, and injecting molten lithium (Li) metal into the porous structure.

[0025] A plurality of interconnected porous channels may be defined based on a plurality of carbon particles. A second film may be formed by nucleating carbon particles at a second concentration level on a first film. The first film may be configured to provide a first electrical conductivity, and the second film may be configured to provide a second electrical conductivity different from the first electrical conductivity. The second electrical conductivity may be lower than the first electrical conductivity.

[0026] The first film may have an average thickness in the range of approximately 10 μm to approximately 200 μm. Carbon particles may be grown in a roll-to-roll processing device. The method may include any one or more of the steps of evaporating molten Li metal onto a metal foil and rolling the molten Li metal from the metal foil into a porous structure. The method may include any one or more of the steps of preparing a cathode prepared by any one or more chemical functionalizations or sulfidation and an anode to participate in the reversible migration of Li ions, and densifying a plurality of graphene sheets on the porous structure.

[0027] Other aspects of the subject matter described in the present disclosure may be implemented as a process for manufacturing a lithium (Li) ion battery anode. The process may include the steps of depositing a first plurality of carbon particles on a substrate and forming a first film configured to provide a first electrical conductivity based on the first plurality of carbon particles. Each of the first plurality of carbon particles may comprise a plurality of 3D aggregates formed of a few-layer graphene sheet configured to orthogonally fuse together to define a porous structure. A porous array is formed in the porous structure. Molten Li metal is injected into the porous structure. The process may include any one or more of the steps of depositing a second plurality of carbon particles on the first film and forming a second film configured to provide a first electrical conductivity based on the second plurality of carbon particles.

[0028] The injection rate of the molten Li metal can be selected according to the viscous resistance of the molten Li metal. The molten Li metal may be configured to react with any one or more of the first plurality of carbon particles to produce a carbide. The process may include any one or more of the steps of infiltrating the molten Li metal into the porous structure in a vapor phase, initiating a chemical reaction between any one or more Li ions provided by the molten Li metal and one or more exposed surfaces of the porous structure, and forming one or more lithium-affinity surfaces from one or more exposed surfaces.

[0029] The process may include the step of coating any one or more of the lithium-affinity surfaces with an active element comprising any one or more of halogens or metal oxides. The process may include the step of coating any one or more of the lithium-affinity surfaces with any one or more elements having a surface energy lower than Li, and the step of promoting the improvement of Li wetting of any one or more of the lithium-affinity surfaces with any one or more elements having a surface energy lower than Li.

[0030] The process may include the step of creating a binder by incorporating any one or more of metal-containing compounds, including metal powder or silicon carbide (SiC), into a carbon preform. Li wetting may include manipulating interfacial surface tension. In some embodiments, Li wetting involves one or more chemical reactions at the interface of Li and the exposed surface of the porous structure. Li wetting enhancement may include any one or more of the steps of adding a certain amount of dopant at the interface and influencing the degree of Li wetting corresponding to the amount of dopant. Brief explanation of the drawing

[0031] 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, drawings, and claims. FIGS. 1a to 1f illustrate diagrams of carbon-based particles having various regions defined for electrical conduction and ion transport. Figures 1h and 1i illustrate schematic diagrams of the arrangement and / or intercalation of Li ions in carbon lattices and structures. Figure 2 illustrates a schematic diagram of a cavity formed by extending in the depth direction into several of the adjacent stacked FL graphene layers. Figure 3 illustrates a schematic diagram of a multilayer carbon-based scaffold structure. FIG. 4a shows a schematic diagram of the structure illustrated in FIG. 3 having lithium (Li) metal injected into a nanoscale gap inside. FIG. 4b illustrates a schematic diagram of a series of plasma spray torches positioned in a continuous sequence on a roll-to-roll (R2R) processing device. Figure 5 illustrates a schematic diagram of an exemplary Li-ion or Li-S electrochemical cell. Figure 6a illustrates a schematic diagram of incorporating metal powder into carbon particles for Li wetting and penetration. Figures 6b and 6c show schematic diagrams of a chemically non-reactive system and a chemically reactive system, respectively. Figure 7 illustrates an exemplary process workflow in which molten Li metal penetrates into the empty spaces between carbon agglomerations. Figure 8a shows the equation for the penetration rate of a carbon-based structure. Figures 8b and 8c show non-reactive and reactive systems regarding Li penetration into carbon structures. FIG. 9 illustrates a flowchart showing exemplary operations for lithiating and alloying a carbon-based structure. FIG. 10a illustrates a flowchart illustrating an exemplary operation for preparing a carbon-based structure. FIG. 10b illustrates a flowchart showing an exemplary operation for preparing a Li material. FIGS. 10c to 10p illustrate flowcharts illustrating exemplary operations for manufacturing an electrochemical cell electrode. FIGS. 11a to 11c illustrate exemplary operations for preparing carbon particles for lithiation. FIG. 12 illustrates a flowchart showing an exemplary operation for performing Li injection of carbon particles. Figure 13 shows a schematic diagram of an anode. Figure 14 illustrates the performance of silicon and carbon anodes over multiple use cycles. Figures 15 and 16 illustrate schematic diagrams related to an ideal cathode configuration in which lithium sulfide (Li2S) nanoparticles are dispersed within graphene. FIGS. 17a and FIGS. 17b illustrate enlarged portions of carbon-based particles of FIGS. 1a to 1f. Figures 18a to 18e are micrographs of the carbon particle portion. Figure 19a shows a schematic diagram of a 3D carbon-based cathode. Figure 19b illustrates a schematic diagram of a 3D carbon-based anode. FIG. 20a illustrates the discharge and charge cycles of an exemplary Li₂S electrochemical cell. FIGS. 20b and 20c illustrate battery performance charts for a battery equipped with a carbon-containing electrode. Figure 21 shows the Raman spectrum for 3D N-doped FL graphene. Figure 22 shows a schematic diagram of double-layer graphene. FIG. 23 illustrates a method for preparing a 3D scaffolded film. In various drawings, similar reference numbers and names represent similar elements. Specific details for implementing the invention

[0032] Various aspects of the novel system, apparatus, and method are described more fully in this specification with reference to the accompanying drawings. However, the disclosed teachings may be embodied in many different forms and should not be interpreted as being limited to any specific structure or function presented throughout the entire disclosure. Rather, such aspects are provided so that the disclosure may be thorough and complete and the scope of the disclosure may be fully conveyed to those skilled in the art.

[0033] Based on the teachings of this specification, those skilled in the art should recognize that the scope of this disclosure is intended to include any aspect of the novel systems, devices, and methods disclosed herein, regardless of whether they are implemented independently or combined with any other aspect of the invention. For example, a device may be implemented or a method may be practiced using any number of aspects described herein. Furthermore, the scope of the invention is intended to include such devices or methods implemented in addition to or using other structures, functions, or structures and functions other than those described herein. Any aspect disclosed herein may be implemented by one or more elements of the claims.

[0034] Although some examples and embodiments are described herein, many variations and substitutions of these examples fall within the scope of this disclosure. While some advantages and benefits of preferred aspects have been mentioned, the scope of this disclosure is not intended to be limited to advantages, uses, or purposes. Rather, the embodiments of this disclosure are intended to be broadly applicable to carbon-based particles self-nucleated in atmospheric pressure vapor streams of carbon-containing gases such as methane, the carbon-based particles comprising multiple electrically conductive three-dimensional (3D) aggregates of graphene sheets defining internal voids and ion conduits, some of which are illustrated in the drawings and the following description of preferred embodiments. The detailed description and drawings are not intended to limit the invention but are merely illustrative, and the scope of the invention is defined by the appended claims and their equivalents.

[0035] definition

[0036] lithium-ion battery

[0037] Lithium-ion batteries are a type of secondary battery, also known as rechargeable batteries. Over the past few years, this battery technology has demonstrated great potential as a power source capable of driving the electric vehicle (EV) revolution by facilitating the widespread implementation of EVs in numerous applications. Consequently, the development of new materials for various components of Li-ion batteries is a focus of research in the field of materials science. Lithium-ion batteries power most modern portable devices and appear to have overcome the psychological barriers for the general public regarding the large-scale use of these high-energy-density devices for more demanding applications, such as EVs.

[0038] In terms of operation, in Li-ion batteries, Li ions (Li+) migrate from the negative electrode, also known as the anode, to the positive electrode through an electrolyte that can be any one or more of a liquid or gel phase during discharge cycles, and return during charge cycles. Conventional lithium-ion batteries may use intercalated Li compounds as the forming material for the positive electrode and graphite for the negative electrode. These batteries can feature a relatively high energy density, measured in specific capacity units of milliampere-hours per gram (mAh / g), and lack a "memory effect"—a situation where nickel-cadmium batteries gradually lose their maximum energy capacity when repeatedly recharged after being partially discharged and having low self-discharge. Unfortunately, unlike many non-Li conventional battery chemistries, Li-ion batteries can pose safety risks due to the high reactivity of elemental and ionic Li. Li batteries can experience unexpected performance degradation, including punctures, abrasive contacts, or overcharging, as well as explosions and fires. Despite these drawbacks, the high energy density of lithium-ion batteries remains attractive, as it allows for a longer service life and cycle life of several hours between charge cycles, which represents the current delivery or output performance of a given Li-ion battery over multiple repetitive charge-discharge cycles, such as partial or full charge-depletion cycles.

[0039] Overall, Li metal still appears to be an ideal material for the negative electrode of lithium-ion secondary batteries due to its high theoretical specific capacity of 3,860 mAh / g, low density (0.59 g cm⁻³), and low negative electrochemical potential of -3.040 V compared to standard hydrogen electrodes. However, issues such as dendrite growth—referring to the growth of branched tree-like structures within the battery itself that can be caused by Li precipitates—continue to persist. Dendrites growing from one electrode to another can cause serious safety issues related to short circuits and lead to limited Coulomb efficiency, which discusses the charging efficiency of electron transfer within the battery during the inherent deposition and stripping behaviors of lithium-ion batteries. These problems have previously hindered lithium-ion battery applications.

[0040] Concerns regarding the safety of previously developed Li secondary batteries have led to the development and improvement of the current generation of Li-ion secondary batteries. These lithium-ion batteries typically feature carbonaceous materials used as an anode, such as carbonaceous anode materials comprising the following:

[0041] graphite;

[0042] Amorphous carbon; and,

[0043] Graphitized carbon.

[0044] The first type of the three carbonaceous materials presented above includes artificial graphite or synthetic graphite, such as highly oriented pyrolytic graphite (HOPG), and natural graphite. Any form of graphite can be intercalated with Li, such as that obtained from a molten Li metal source. The resulting graphite intercalation compound (GIC) is Li xIt can be expressed as C6, where X is typically less than 1. To limit or minimize energy density loss by replacing Li metal with GIC, Li x X of C6 must be maximized and the irreversible capacity loss (Q) in the first charge of the battery ir ) must be minimized.

[0045] As a result, the maximum amount of Li that can be reversibly intercalated into the gaps between graphene planes of a perfect graphite crystal is generally Li corresponding to theoretically 372 mAh / g. x It is believed to occur in graphite intercalation compounds represented by C6 (x=1). However, such limited capacity cannot adequately meet the demanding requirements of higher energy density power requirements for modem electronic devices and EVs. Therefore, carbon-based anodes, such as Li-intercalated graphite, can exhibit extended cycle life due to the presence of a surface electrolyte interface (SEI), which occurs during the first few charge-discharge cycles due to reactions between Li and the surrounding electrolyte, or between Li and anode surface / edge atoms or functional groups. The Li ions consumed in these reactions represent the formation of the SEI and can be derived from some Li ions originally intended for charge transport, referencing the process of elemental Li dissociating when intercalated with carbon in carbon-based structures, such as within the anode.

[0046] Charge transport can occur during the migration of Li-ions from the electrolyte to the cathode across the porous separator, in relation to electron emission and transport to facilitate current conduction for powering the load during a typical Li-ion battery discharge cycle. It is explained that during repeated lithium-ion battery charge-discharge cycles, an SEI forms, and some Li-ions moving through the electrolyte become "irreversible" in that they become part of the inert SEI layer and can no longer serve as active elements or ions used for charge transport. Consequently, it is desirable to minimize the amount of Li used for effective SEI layer formation. In addition to SEI formation, Q ir It is due to graphite exfoliation caused by electrolyte / solvent simultaneous intercalation and other side reactions.

[0047] Next, amorphous carbon contains no or almost no micro or nano crystallites and may include both "soft carbon" and "hard carbon." Soft carbon refers to a carbon material that can be graphitized at a temperature of about 2,500°C or higher. In contrast, hard carbon refers to a carbon material that is not graphitized at a high temperature of 2,500°C or higher.

[0048] In practice and industry, the so-called "amorphous carbon" commonly used as an anode active material may not be purely amorphous but rather may contain minute amounts of microcrystalline or nanocrystalline particles, each defined as a small number of graphene sheets oriented toward a basal plane that are stacked and bonded together by weak van der Waals forces. The number of graphene sheets can vary between one and several hundred, typically with a thickness L ranging from 0.34 nm to 100 nm. e It generates c-direction dimensions such as. The length or width (L) of these determinants. aThe range is generally between tens of nanometers and microns. Among these types of carbon materials, soft and hard carbon can be produced by low-temperature pyrolysis (550-1,000°C) and exhibit a reversible specific capacity of 400-800 mAh / g in the 0-2.5V range. So-called "house-of-cards" carbon materials have been produced with an improved specific capacity approaching 700 mAh / g.

[0049] The research group obtained an enhanced capacity of up to 700 mAh / g by milling graphite, coke, or carbon fibers, and explained the origin of the additional capacity by assuming that Li ions are adsorbed on both sides of a single graphene sheet in disordered carbon containing some dispersed graphene sheets, referred to as "House of Cards" materials. It was suggested that Li readily binds to proton-passivated carbon to create a series of edge-oriented Li-to-CH bonds. This can provide an additional source of Li+ in some disordered carbon. Another study proposed the formation of a Li metal monolayer on the outer graphene sheets of graphite nanocrystals. The discussed amorphous carbon was prepared by the pyrolysis of epoxy resin and can be referred to as polymerized carbon. Polymerized carbon-based anode materials were also investigated.

[0050] Chemical, performance, cost, and safety characteristics may vary depending on the Li-ion battery variant. Portable electronic devices may use Li-polymer batteries, utilizing lithium cobalt oxide (LiCoO2) as the cathode material and a polymer gel as the electrolyte. While this configuration can provide relatively high energy density, it may present safety risks, particularly when damaged. Lithium iron phosphate (LiFePO4), lithium-ion manganese oxide batteries (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 risk of fire or explosion. Consequently, these batteries are widely used in applications such as power tools and medical devices. NMC, in particular, is frequently considered for automotive applications.

[0051] Lithium (Li) - Sulfur (S) Battery

[0052] Lithium-sulfur batteries, referred to as Li-S batteries in this specification, are a notable type of rechargeable battery due to their high specific energy. Due to the relatively low atomic weight of Li and the moderate atomic weight of S, Li-S batteries are relatively light, with a density approximately equal to that of water.

[0053] Li-S batteries can succeed lithium-ion batteries due to their higher energy density and reduced costs resulting from the use of sulfur. Li-S batteries can provide a specific energy of approximately 500 Wh / kg, which is significantly superior to many existing lithium-ion batteries that typically range from 150 to 250 Wh / kg. Li-S batteries with up to 1,500 charge-discharge cycles have been demonstrated. Despite these many advantages, a key challenge facing Li-S batteries is the polysulfide "shuttle" effect, where active material progressively leaks from the cathode, shortening the battery's overall lifespan. Furthermore, the extremely low electrical conductivity of sulfur cathodes requires additional mass of the conductor to utilize the full contribution of the active mass to the capacity. The significant volumetric expansion of the S cathode from elemental S to Li2S and the requirement for a large amount of electrolyte are also problematic areas that require attention.

[0054] The chemical processes of Li-S batteries include incorporation into alkali metal polysulfide salts and dissolution of Li from the anode surface during discharge, and reverse lithium plating on the anode during charging. Dissolution of metallic lithium occurs at the anode surface, electrons and lithium ions are generated during discharge, and electrodeposition occurs during charging. The half-reactions are expressed as follows:

[0055] (Equation 1)

[0056] Similar to what is observed in Li-ion batteries, dissolution and / or electrodeposition reactions can cause unstable growth problems at the solid electrolyte interface (SEI) over time, creating active sites for Li nucleation and dendrite growth. Dendrite growth is responsible for internal short circuits in Li batteries and leads to the failure of the battery itself.

[0057] In a Li-S battery, energy is stored in the sulfur electrode (S8), which acts as the cathode. During the battery discharge cycle, Li ions in the electrolyte migrate from the anode to the cathode, reducing S to lithium sulfide (Li2S). Sulfur is reoxidized to S8 during the recharging phase. For illustrative purposes, the semi-reaction is represented by a high level of abstraction as follows:

[0058] (Equation 2)

[0059] In fact, the S reduction reaction for Li2S is much more complex, and several Li polysulfides (Li2S) at decreasing chain lengths in the following order x Includes the formation of , 8 < x < 1):

[0060] (Equation 3)

[0061] The final product is not pure Li2S resulting from the slow reduction kinetics of Li2S, but a mixture of Li2S2 and Li2S. This contrasts with conventional lithium-ion batteries where lithium ions are intercalated at both the anode and the cathode. For example, in a Li2S battery system, each S atom can host two Li ions. Typically, lithium-ion batteries can accommodate only 0.5–0.7 lithium ions per host atom. Consequently, Li2S allows for a much higher Li storage density. Polysulfides (PS) are reduced in turn at the cathode surface during battery discharge:

[0062] (Equation 4)

[0063] S polymer is formed at the cathode across the porous diffusion separator when the battery is charged:

[0064] (Equation 5)

[0065] This reaction may be similar to the reaction of a sodium (Na)-S battery.

[0066] Major challenges regarding Li-S battery systems include the relatively low conductivity of sulfur and the significant volume change during discharge; finding a suitable cathode, such as one composed of any of the currently disclosed carbon-based structures, is the first step toward the commercialization of Li-S batteries. Currently, conventional Li-S batteries utilize a carbon / sulfur cathode and a lithium anode. Although sulfur is abundant in nature and relatively inexpensive, 5 x 10⁻⁶ at 25°C -30 There is almost no electrical conductivity of S·cm⁻¹. Carbon coatings provide the missing electrical conductivity. Although carbon nanofibers have the disadvantage of being expensive, they provide effective electron conduction pathways and structural integrity.

[0067] One problem with Li-S design is that when the S at the cathode absorbs Li, Li x The volume expansion of the S composition occurs, and the expected volume expansion of Li2S is nearly 80% of the original S volume. This causes large mechanical stress in the cathode, which is a major cause of rapid degradation. This process reduces contact between carbon (C) and S and prevents the flow of Li ions to the carbon surface.

[0068] The mechanical properties of lithiated S compounds depend significantly on the Li content; while the strength of lithiated S compounds improves with increasing Li content, this increment is not linear with Li. One of the major drawbacks of most Li-S batteries concerns unwanted reactions with the electrolyte. Although S and Li2S are relatively insoluble in most electrolytes, many intermediate polysulfides (PS) contain Li2S nDissolving it in the electrolyte cannot cause irreversible loss of active S. When highly reactive Li is used as the negative electrode, most other commonly used types of electrolytes dissociate. The use of a protective layer on the anode surface has been studied to improve battery safety, such as using Teflon coatings which have shown improved electrolyte stability, and LIPON and Li3N have also demonstrated promising performance.

[0069] The "shuttle" effect has been observed as a major cause of degradation in Li-S batteries. Li PS Li2S x (6 ≤ x ≤ 8) dissolves well in the common electrolyte used in Li-S batteries. They form at the cathode, leak out, diffuse into the anode to be reduced to short-chain PS, and then diffuse back into the cathode to form long-chain PS. This process results in continuous leakage of active material from the cathode, lithium corrosion, low Coulomb efficiency, and a short battery life due to battery self-discharge. Furthermore, the "shuttle" effect is responsible for the characteristic self-discharge of Li-S batteries due to the slow dissolution of PS that occurs even in the idle state. The "shuttle" effect of Li-S batteries is a coefficient f, which is evaluated as an extension of the charge voltage stabilizer. c (0 <f c It can be quantified as < 1). The coefficient fc is provided by the following formula:

[0070] (Equation 6)

[0071] Here k s , q up , [S tot ] and I c ε₀ is the kinetic constant, the specific capacitance contributing to the anode stabilizer, the total sulfur concentration, and the charging current, respectively.

[0072] Electrical conductivity of carbon-based materials

[0073] Due to advancements in highly conductive carbon materials such as carbon nanotubes (CNT), graphene, amorphous carbon, and / or crystalline graphite in electronic products, these materials can be printed on various types of surfaces without using materials or compounds identified as toxic to the human body or without using printed circuit boards. The use of highly conductive carbon as a feedstock or other material during any one or more of the additive manufacturing processes described above can facilitate the fabrication of batteries with fine lattice structures suitable for enhanced functionality, power storage and transmission, and optimal efficiency. While many of the described devices can be used as power sources such as batteries or capacitors, those skilled in the art will recognize that printing technologies such as 3D printing can be configured to form other electronic devices using highly conductive carbon materials such as carbon nanotubes (CNT), graphene, amorphous carbon, or crystalline graphite.

[0074] Printing technology using highly conductive carbon materials such as carbon nanotubes (CNT), graphene, amorphous carbon, or crystalline graphite can be implemented and / or otherwise integrated into the fabrication of the following devices: antennas, tuned antennas, sensors, biosensors, energy harvesters, photovoltaic cells, and other electronic devices.

[0075] graphene

[0076] Graphene is a carbon allotrope in the form of a single atomic layer in a two-dimensional hexagonal lattice where one atom forms each vertex. It is the basic structural element of other allotropes, including graphite, charcoal, carbon nanotubes, and fullerenes. It can also be considered an infinitely large aromatic molecule, which is the ultimate case of the flattened polycyclic aromatic hydrocarbon series.

[0077] Graphene possesses a special set of properties that distinguish it from other elements. It is approximately 100 times stronger than the strongest steel in proportion to its thickness. However, its density is significantly lower than any other steel, with a surface-related mass of 0.763 mg per square meter. It conducts heat and electricity very efficiently and is nearly transparent. Graphene also exhibits much greater nonlinear diamagnetism than graphite and can be levitated by Nd-Fe-B magnets. Researchers have identified bipolar transistor effects, ballistic charge transport, and large quantum oscillations in the material. End-use applications are extensive; not only do they find unique implementations in advanced materials and composites, but they are also used as a forming material to construct colorful scaffolds for Li-ion battery electrodes, enhancing ion transport and current conductivity to yield capacity and power transfer figures unattainable with conventional battery technology.

[0078] Chemical functionalization of graphene

[0079] Functionalization refers to the process of adding new functions, characteristics, capabilities, or properties to a material or substance by altering its surface chemistry. Functionalization is used across chemistry, materials science, biotechnology, textile engineering, and nanotechnology, and can be performed through the adsorption or attachment of atoms, ions, or molecules from gases, liquids, or dissolved solids to a surface to create a film of adsorbents without forming covalent or ionic bonds, or by attaching molecules or nanoparticles to the surface of a material via chemical bonds.

[0080] The functionalization and dispersion of graphene sheets can be critical for their respective end-use applications. Chemical functionalization of graphene enables the material to be processed using solvent-assisted techniques such as layer-by-layer assembly, spin coating, and filtration, while also preventing the aggregation of single-layer graphene (SLG) during reduction and preserving the intrinsic properties of graphene.

[0081] Currently, the functionalization of graphene can be performed by covalent and non-covalent modification techniques. In both cases, functionalized graphene was obtained by performing reduction following surface modification of graphene oxide. Both covalent and non-covalent modification techniques have been found to be highly effective for the preparation of processable graphene.

[0082] However, the electrical conductivity of functionalized graphene has been observed to be significantly reduced compared to pure graphene. Furthermore, the surface area of ​​functionalized graphene prepared by covalent and non-covalent techniques is greatly reduced due to sonication, functionalization, and chemical reduction following the destructive chemical oxidation of flake graphite. To overcome these problems, studies have been reported on preparing functionalized graphene directly from graphite via a one-step process. In all these cases, surface modification of graphene can prevent aggregation and promote the formation of a stable dispersion. Surface-modified graphene can be used in the fabrication of polymer nanocomposites, Li-ion battery electrodes, supercapacitor devices, drug delivery systems, solar cells, memory devices, transistor devices, biosensors, and the like.

[0083] black smoke

[0084] Graphite, as generally understood and referred to herein, refers to the crystalline form of elemental carbon having atoms arranged in a hexagonal structure. Graphite occurs naturally in this form and is the most stable form of carbon under standard conditions, such as the atmosphere. Otherwise, under high pressure and temperature, graphite transforms into diamond. Graphite is used in pencils and lubricants. Due to its high conductivity, it is useful in electronic products such as electrodes, batteries, and solar panels.

[0085] Roll-to-roll (R2R) processing

[0086] R2R processing refers to the process of making electronic devices on rolls of flexible plastic or metal foil. R2R processing may also refer to any process that involves applying a coating, printing, or performing other processes such as starting with a roll of flexible material and winding it back up after the process to create an output roll. These processes and other processes, such as sheet metal, can be grouped together under the general term "conversion." Once the roll of material is coated, laminated, or printed, it can be cut and / or trimmed to its final size in a slitter rewinder.

[0087] R2R processing of large-area electronic devices can reduce manufacturing costs. Other applications utilizing the flexible properties of the substrate, such as electronic devices embedded in clothing, 3D-printed Li-ion batteries, large-area flexible displays, and roll-up portable displays, may arise.

[0088] Oxidation-reduction (redox) reaction

[0089] Redox is a type of chemical reaction in which the oxidation state of an atom changes. Redox reactions are characterized by the transport of electrons between chemical species; most commonly, one species, the reducing agent, is oxidized by losing electrons, while another species, such as the oxidizing agent, undergoes reduction by gaining electrons. A chemical species from which electrons are removed is said to be oxidized, while a chemical species from which electrons are added is said to be reduced.

[0090] Intercalation

[0091] Intercalation refers to the reversible inclusion or insertion of molecules or ions into a material having a layered structure. Examples can be found in graphite, graphene, and transition metal dichalcogenides.

[0092] Lithium intercalation in bilayer or multilayer graphene

[0093] The electrical storage capacity of graphene and the Li storage process of graphite present challenges requiring further development in the field of lithium-ion batteries. Therefore, efforts have been made to investigate Li storage capacity, process, kinetics, and resistance, and to develop a type of bilayer graphene in which half the atoms are positioned directly above the hexagonal center of the underlying graphene sheet and half are positioned above it, as well as to develop defect-free 3D bilayer graphene with a predominant Bernal stacking configuration. Li atoms can be stored only in the graphene interlayer. Furthermore, the various physicochemical properties of stepwise Li bilayer graphene products further elucidate regular Li intercalation phenomena and explain these two-dimensional Li storage patterns.

[0094] Electrochemical capacitor (EC)

[0095] Electrochemical capacitors (ECs), also referred to as ultracapacitors or supercapacitors, are being considered for use in hybrid or full EVs. ECs can complement or replace conventional batteries, including high-performance Li-ion batteries used in EVs, for specific applications by providing short bursts of power, such as those required for forward propulsion often needed for high-speed acceleration. While traditional batteries can still be used to provide uniform power for cruising at normal highway speeds, supercapacitors possess the ability to release energy much faster than batteries, allowing them to activate and replenish the power provided by the battery at specific times, such as when the vehicle needs to accelerate for merging, overtaking, emergency maneuvers, or climbing hills.

[0096] The EC must also store sufficient energy to provide an acceptable driving range, such as 220 to 325 miles or more. Additionally, to ensure high cost and weight efficiency relative to the additional battery capacity, the EC must combine appropriate non-energy and non-power with a long cycle life and meet cost targets. Specifically, for EVs, the EC must be able to store approximately 400Wh of energy and supply approximately 40kW of power for about 10 seconds, and provide a high cycle life of >100,000 cycles.

[0097] The high volumetric capacitance density of ECs, which is 10 to 100 times greater than that of conventional capacitors, is derived by creating a large effective "plate area" using porous electrodes that can incorporate, feature, and / or configure scaffolded graphene-based materials, and by storing energy in a diffusion bilayer. This bilayer, which is naturally formed at the solid-electrolyte interface when voltage is applied, has a thickness of about 1–2 nm, thus forming a very small effective "plate separation." In some ECs, the stored energy is further increased by pseudo-capacitance effects and recurs at the solid-electrolyte interface due to electrochemical phenomena such as redox charge transport. Bilayer capacitors are based on high-surface-area electrode materials, such as activated carbon, immersed in the electrolyte. A polarized bilayer is formed at the electrode-electrolyte interface, providing high capacitance.

[0098] outline

[0099] introduction

[0100] Technological advancements regarding modern carbon-based materials, such as graphene, have consequently enhanced the application of these materials in many end-use areas, such as advanced secondary batteries. These batteries may utilize electrochemical Li intercalation or deintercalation to leverage the advantageous properties of carbon and carbon-based materials, which can also depend significantly on their respective morphologies, crystallinity, crystallite orientation, and defects. For example, the electrical storage capacity of lithium-ion batteries can be enhanced by the selection and incorporation of desirable nanostructured carbon materials, such as graphite and graphene, or specific allotropes of carbon like nanoscale graphite, nanofibers, insulated single-walled carbon nanotubes, nanoballs, and nanoscale amorphous carbon, each having small carbon nanostructures with dimensions not exceeding about 2 µm.

[0101] A known method for manufacturing carbon and Li-ion electrodes for rechargeable Li batteries comprises the step of forming a carbon electrode. Such a carbon electrode may consist of graphitic carbon particles bonded together by an ethylenepropylene diene monomer binder used to achieve a carbon electrode capable of subsequent intercalation by Li-ions. The carbon electrode then reacts with infiltrated lithium (Li) metal to incorporate Li-ions obtained therefrom into the graphitic carbon particles of the electrode. Voltage may be repeatedly applied to the carbon electrode to initially induce a surface reaction between Li-ions and carbon, and subsequently cause Li-ions to intercalate into the crystalline layer of the graphitic carbon particles. Repeated application of voltage may enable intercalation to be achieved close to a theoretical maximum and may facilitate desirable current conduction.

[0102] Other exfoliated graphite-based hybrid material compositions are related to the following:

[0103] Micron or nanometer-sized particles or coatings capable of absorbing and desorbing alkali or alkaline metal ions, particularly Li ions; and,

[0104] Exfoliated graphite flakes substantially interconnected to form a porous conductive graphite network containing internally defined pores.

[0105] Particles or coatings are present in the pores of the network or attached to the flakes of the network. The amount of exfoliated graphite is in the range of 5 to 90 weight%, and the number of particles or coating amount is in the range of 95 to 10 weight%.

[0106] Furthermore, high-capacity silicon-based anode active materials were found to be effective when combined with high-capacity lithium-rich cathode active materials. Supplemental Li was shown to improve cycling performance and reduce irreversible capacity loss in some silicon-based active materials. Silicon-based active materials can be formed into composites with electrically conductive coatings, such as pyrolytic carbon coatings or metal coatings, and the composites can also be formed from other electrically conductive carbon components, such as carbon nanofibers and carbon nanoparticles.

[0107] In addition, a rechargeable alkali metal battery having a known organic electrolyte has almost no capacity loss due to the intercalation of the carbonaceous electrode and the alkali metal. The carbonaceous electrode may comprise a multiphase composition including both a highly graphitized phase and a less graphitized phase, or may comprise a single phase highly graphitized composition intercalated with Li at temperatures above about 50°C. The incorporation of an electrically conductive filament material, such as carbon black, closely interspersed with the carbonaceous composition minimizes capacity loss during repeated cycling.

[0108] Alternatively, the known Li-based anode material is a carbonaceous anode active material with a specific surface area of ​​1 m² 2It may be characterized by comprising a fiber diameter formed of a styrene-butadiene rubber binder and carbon fibers of 1,000 nanometers, with a content of 1 g or more. Such an anode material is used in a Li battery having desirable characteristics such as low electrode resistance, high electrode strength, excellent permeability, high energy density, and high charge / discharge rate. The negative electrode material contains 0.05 to 20 mass% of carbon fibers and 0.1 to 6.0 mass% of styrene. Butadiene rubber forms a binder and may further contain 0.3 to 3 mass% of a thickener such as carboxymethyl methylcellulose.

[0109] Existing technology related to batteries having the following anode active material has been shown:

[0110] Pre-lithiation; and,

[0111] Pre-pulverized.

[0112] Such an anode may be prepared in a manner including the following:

[0113] Step of providing an anode active material;

[0114] A step of producing a pre-lithiated anode active material by intercalating or absorbing a desired amount of Li into the anode active material;

[0115] A subdivision step, meaning reducing the solid material from one average particle size to a smaller average particle size through grinding, grinding, cutting, vibration, or other processes, into fine particles smaller than the average size of a pre-lithiated anode active material, preferably < 1 µm, most preferably < 200 nm; and,

[0116] A step of forming an anode by combining multiple fine particles of a pre-lithiated anode active material with a conductive additive and / or binder material.

[0117] Pre-lithiated particles are protected by a Li-ion conductive matrix or coating material. The matrix material is reinforced with nanographene sheets.

[0118] Graphitic nanofibers have also been disclosed, comprising tubular fullerenes, generally referred to as "buckytubes," nanotubes, and fibrils functionalized by chemical substitution, and are used as electrodes in electrochemical capacitors. Graphitic nanofiber-based electrodes improve the performance of electrochemical capacitors. Preferred nanofibers are approximately 200 m² 2 It has a surface area exceeding / gm and is practically free of micropores.

[0119] In addition, the disclosed high surface area carbon nanofiber has an outer surface formed with a porous high surface layer. A method for manufacturing the high surface area carbon nanofiber comprises thermally decomposing a polymerizable coating material provided on the outer surface of the carbon nanofiber at a temperature lower than the melting temperature of the polymerizable coating material. The polymerizable coating material used for the high surface area around the carbon nanofiber may include phenolic materials such as formaldehyde, polyacrylonitrile, styrene, divinylbenzene, cellulose polymer, and cyclotrimeric diethynylbenzene. The high surface area polymer covering the carbon nanofiber may be functionalized with one or more functional groups.

[0120] Currently disclosed carbon synthesis

[0121] As presented above, a conventional Li-intercalation carbon-based composition or compound may include the following conventional battery electrode materials:

[0122] Graphene or multilayer 3D graphene particles;

[0123] Electrically conductive carbon particles; and,

[0124] A binder, provided in a fluid form such as a liquid and / or in the form of particulates, is configured to hold carbon-based particles in their respective desired locations and provide overall structural integrity to the carbon-based system.

[0125] In conventional techniques, particles are typically deposited by dropping them onto a conventional slurry-cast electrode containing a current collector made of a metal foil, such as copper. The slurry is prepared to contain an organic binder or binder material called NMP, which is an organic compound composed of a 5-membered lactam used as a solvent in the petrochemical and plastics industries, utilizing its non-volatility and ability to dissolve various materials. The ratio of the active material to the conductive carbon or carbon-based particles generally forms a dominant balance of the active material and the nominal amount of the binder or binder material, such as NMP, with 5 parts conductive carbon. The relative amounts of the conductive phase of the binder and carbon can be determined by creating electrically conductive paths or channels between the larger of the two particles.

[0126] Regarding the challenges associated with the implementation and use of binders in secondary batteries, research indicates that developing high-performance battery systems requires the optimization of all battery components, ranging from electrodes and electrolytes to binder systems. However, conventional strategies for fabricating battery electrodes by casting a mixture of active materials, non-conductive polymer binders, and conductive additives onto metal foil current collectors generally result in electron or ion bottlenecks and poor contact due to randomly distributed conductive phases, which can be issues observed at the anode or cathode. Furthermore, when using high-capacity electrode materials, the mechanical integrity of existing binder systems can be compromised due to high stresses generated during electrochemical reactions, potentially shortening battery life. Therefore, it is crucial to design novel, robust binder systems or scaffolded carbon-based electrode structures that demonstrate structural integrity without the need for binders, capable of retaining the active material where and when desired during battery charge-discharge cycles and providing stable, low-resistance, and continuous internal voids, micropores, and pathways that connect all regions of the electrode.

[0127] In contrast to traditional practices, and to address the defects in binder performance associated with reduced cycle life of batteries, the material composition and method or process of manufacturing the present invention disclosed herein can eliminate the following:

[0128] Any and all forms of binder steps; and,

[0129] Potentially specific regions, features, and / or modes of a conductive phase defined by larger carbon-based particles comprising a graphene form extracted from or generated from graphite and / or graphite exfoliation.

[0130] This is accomplished by manufacturing particles in which interconnected 3D aggregates of multiple layers of graphene sheets are fused or sintered together using random or controlled orientations, such as orthogonal ones; or otherwise bonded together to act as a kind of intrinsic, self-supporting "bonder"; or bonding materials acting as binder substitutes can effectively eliminate separate conventional binder materials, thereby achieving significant weight reduction. This format may also eliminate separate, dedicated current collectors, which are typically essential components of many batteries. The elimination of the binder phase and / or current collector provides the following beneficial and desirable functions:

[0131] Mass production is possible due to the low production cost per unit, and

[0132] High reversible specific capacity,

[0133] Low irreversible capacity,

[0134] Small particle size, such as allowing high throughput / speed capacity,

[0135] For convenient integration and use in commercial battery applications, compatibility with commonly used electrolytes and

[0136] Long charge-discharge cycle life for consumer benefits across demanding end-use applications, including automobiles, airplanes, and spacecraft.

[0137] In particular, the techniques disclosed herein yield unexpected advantageous results. They do not require traditional processes such as graphite exfoliation to produce graphene sheets, but instead synthesize one or more multimodal carbon-baseds in an atmospheric plasma-based vapor stream. The synthesis of carbon-based particles can occur while flying to nucleate from initially formed homogeneous carbon-based nuclei or while depositing directly onto a supporting or sacrificial substrate. Thus, any one or more of the techniques currently disclosed allow for the growth of colorful carbon-based structures independent of the seed particles traditionally required for nucleation.

[0138] In conventional technology, the production of functional graphene relies on the use of graphite as a starting material. Graphite, a conductive material, has been used as an electrode in batteries and other electrochemical devices. In addition to its function as an inert electrode, graphite intercalation compounds (GICs) have been formed using electrochemical methods, and more recently, graphite has been exfoliated into few-layer graphene. Exfoliation, as generally understood and referred to herein in the context of intercalation chemistry, refers to the complete separation of material layers and typically requires aggressive conditions involving highly polar solvents and aggressive reagents. Electrochemical methods are attractive in that they eliminate the use of chemical oxidizers as the driving force for intercalation or exfoliation and allow for control of the electromotive force for tunable GICs. More importantly, the extensive capabilities of electrochemical functionalization and modification enable the easy synthesis of functional graphene and its value-added nanohybrid.

[0139] Unlike exfoliation involving the thermal exfoliation of graphite to produce graphene, the method disclosed herein relates to one or more carbon-containing gas species, such as methane (CH4), flowed into a reaction chamber of a microwave-based or thermal reactor. Upon receiving energy, such as that provided by electromagnetic radiation and / or thermal energy, the incoming gas species spontaneously fractures to form allotropes with other fractured carbon from additional gas species supplied to the reactor to create initial carbon-based sites, such as particles, which have or promote the following:

[0140] Additional particles that grow from defects of initially formed particles or form nuclei; or,

[0141] Additional carbon-based particles with sufficient local energy at the collision point for the colliding particles to combine are orthogonally fused or sintered.

[0142] System structure

[0143] Carbon-based particles - Details

[0144] FIG. 1a illustrates carbon-based particles (100A) having an internally controllable electrical and ion conduction gradient, wherein various aspects of the subject matter disclosed herein may be implemented. The carbon-based particles (100A) may be synthesized through self-assembly independent of a binder to feature multimodal dimensions including various orifices, conduits, pores, paths, etc., any one or more of which are defined as having specific dimensions as mesoporous. A mesoporous material means a material having pores with a diameter of 2 to 50 nm according to IUPAC nomenclature. For comparison, IUPAC defines microporous materials as materials having pores with a diameter of less than 2 nm and macroporous materials as materials having pores with a diameter of 50 nm or more.

[0145] Mesoporous materials can include various types of silica and alumina possessing mesopores of similar size. Mesoporous oxides of niobium, tantalum, titanium, zirconium, cerium, and tin have been studied and reported. Among all variations of mesoporous materials, mesoporous carbon, such as carbon and carbon-based materials, has achieved particular importance as it possesses pores, orifices, pathways, conduits, etc., has at least one mesoporous dimension, and can be directly applied to energy storage devices. Mesoporous carbon can be defined as having porosity within the mesopore range, which significantly increases the specific surface area. Another common mesoporous material is activated carbon, which refers to a form of carbon treated to have small, low-volume pores that increase the surface area. In the context of mesopority, activated carbon typically consists of a carbon framework that possesses both mesoporous and microporous properties depending on the synthesis conditions. According to IUPAC, mesoporous materials can be disordered or ordered in their mesostructure. In crystalline inorganic materials, the mesoporous structure significantly limits the number of lattice units, which greatly alters solid-state chemistry. For example, the battery performance of mesoporous electroactive materials differs significantly from that of bulk-structured batteries.

[0146] Carbon-based particles (100A) are nucleated and grown in an atmospheric pressure plasma-based vapor stream of a reagent gaseous species such as methane (CH4) to form initial carbon-containing and / or carbon-based particles without specifically or explicitly requiring a separate, standalone initial seed particle to which the carbon structure subsequently grows, as seen in the prior art. The initial carbon-based synthetic particles independent of a separate seed particle according to the presently disclosed embodiments can be extended as follows:

[0147] Describes systematic coalescence resulting from nucleation and / or growth from an initial homogeneous carbonaceous nucleation independent of seed particles of additional carbonaceous material induced from an air-introduced carbon-containing gas within a microwave plasma reaction chamber, such as illustrated by the micrograph (100D) of FIG. 1d; or,

[0148] Grows and / or is deposited directly on a supporting or sacrificial substrate, such as a current collector, within a thermal reactor.

[0149] Cohesion refers to a process in which two phase regions of the same composition come together to form a larger phase region. Or, it is a process in which two or more separate masses of mixed material appear to attract each other even with only slight contact. Carbon-based particles (100A) may alternatively be referred to simply as particles and / or any other similar term. The term mesoporous, as generally understood and used herein, may be defined as a material containing pores with a diameter of 2 to 50 nm according to the International Union of Pure and Applied Chemistry (IUPAC) nomenclature.

[0150] The synthesis and / or growth of carbon-based particles (100A) within a microwave-based reactor, such as a reactor, and / or within a reaction chamber associated therewith is disclosed by Stowell, et al. in U.S. Patent No. 9,767,992, filed September 19, 2017, in “Microwave Chemical Processing Reactor,” the entirety of which is incorporated herein by reference. Synthesis may occur in systems other than microwave reactors, such as those occurring in thermal reactors, which generally refer to chemical reactors defined as closed volumes in which temperature-dependent chemical reactors occur.

[0151] The carbon-based particles (100A), also illustrated as carbon-based particles (100E) in FIG. 1e, are synthesized as described herein into a three-dimensional (3D) hierarchical structure comprising short-range, local nano-structuring combined with long-range approximate fractal feature structuring, which in the context refers to the formation of continuous layers orthogonally to one another. Here, orthogonality is defined as including a 90-degree rotation of each continuous layer with respect to the layer below, etc., and enables the creation of vertical or substantially vertical layers and / or intermediate layers.

[0152] An adjacent microstructure (107F) suitable for incorporation into the cathode of an electrochemical cell for a lithium-sulfur (Li₂S) secondary system is illustrated in FIG. 1f, which itself provides an enlarged and more detailed view of the hierarchical pores (101A) illustrated in FIG. 1a and 1e. In some embodiments, the contour and shape of the adjacent microstructure (107F) may structurally define an open porous scaffold (102A) illustrated in FIG. 1a having a diffusion path (109F) suitable for Li ion transport from the anode to the cathode during a discharge-charge cycle. The adjacent microstructure (107F) may include the following:

[0153] A microporous framework such as a diffusion path (109F) defined by dimensions (101F) of > 50 nm providing an adjustable Li ion conduit;

[0154] Mesoporous channels defined by dimensions of about 20 nm to about 50 nm (101F) acting as Li-ion highways for rapid Li-ion transport internally (generally defined by IUPAC nomenclature and referred to as mesopores or mesoporous); and

[0155] Microporous texture such as pores (105F) defined by dimensions (103F) of < 4 nm for charge acceptance and / or limiting of active materials such as sulfur (S) in Li S systems.

[0156] A hierarchical porous network (100F) including diffusion pathways (109F) may be configured to define adjacent microstructures (107F) to provide an active Li intercalating structure, in addition to providing pores (105F) to confine active material and define pathways for ion transport. Thus, a hierarchical porous network (100F) of carbon-based particles (100E) may be implemented in an anode or cathode, or in a Li-ion or Li-S battery system having a rated specific capacity between, for example, about 744 mAh / g and about 1,116 mAh / g. For a Li-ion or Li-S configuration, Li may penetrate into an open porous scaffold, such as when provided by molten Li metal via capillary injection, and chemically react at least partially with the exposed carbon within the reactive system.

[0157] One or more physical, electrical, chemical, and / or material properties of the carbon-based particles (100A) may be defined during synthesis. Additionally, dopants representing trace impurity elements introduced into the chemicals to alter original electrical or optical properties, such as Si, SiO, SiO2, Ti, TiO, Sn, Zn, etc., are dynamically incorporated during the synthesis of the carbon-based particles (100A) to at least partially affect material properties including electrical conductivity, wettability, and / or ion conduction or transport through the hierarchical porous network (100F). Microporous textures having dimensions (103F) and / or a hierarchical porous network (100F) may be synthesized, manufactured, or produced to include smaller pores for chemicals such as sulfur (S) or micro-confinement, and the smaller pores are defined in the range of 1 to 3 nm. Additionally, as shown in FIG. 1c, each graphene sheet has a diameter (L a ) may be in the range of 50 to 200 nm.

[0158] The open porous scaffold (102A) can be synthesized independently of a binder, such as a traditional non-conductive polymer binder typically used with a conductive additive on a metal foil current collector in battery end-use applications. Conventional configurations involving the use of binders can cause electron / current conduction issues or ion shrinkage and poor contact due to randomly distributed conductive phases. Additionally, when using high-capacity electrode materials, the relatively high physical stress generated during electrochemical reactions can impair the mechanical integrity of the conventional binder system, consequently shortening the battery's lifespan.

[0159] A vapor stream used to synthesize carbon-based particles (100A) or carbon-based particles (100E) that are identical or may be identical to carbon-based particles (100A) may flow at least partially near a plasma, such as being generated and / or introduced into a reactor and / or chemical reaction vessel. Such a plasma reactor may be configured to propagate microwave energy toward the vapor stream to at least partially support the synthesis of carbon-based particles (100A) and may include carbon particle-based and / or induced nucleation and growth from constituent carbon-based gaseous species such as methane (CH4), wherein such nucleation and growth may occur substantially from an initially formed carbon-based homogeneous nucleation independent of the seed particles within the reactor. Such a reactor accommodates the control of a gas-solid reaction under non-equilibrium conditions, wherein the gas-solid reaction may be at least partially controlled by one or more of the following:

[0160] Ionization potential and / or thermal energy associated with constituent carbonaceous gas species introduced into the reactor for the synthesis of carbonaceous particles; and / or

[0161] Kinetic momentum associated with gas-solid reactions.

[0162] The vapor flow stream can flow into a reactor and / or reaction chamber for the synthesis of carbon-based particles (100A) substantially at atmospheric pressure. And, a change in the wettability of any component such as carbon-based particles (100A) and / or an open porous scaffold (102A) may involve at least partially adjusting the polarity of the carbon matrix associated with the carbon-based particles (100A).

[0163] Synthesis procedure

[0164] microwave reactor

[0165] A vapor stream containing carbon-containing constituent species such as methane (CH4) can be flowed into one of two common reactor types to produce carbonaceous particles (100A):

[0166] Thermal reactor; or,

[0167] Microwave-based reactor. A suitable type of microwave reactor is disclosed in “Microwave Chemical Processing Reactor” by Stowell et al., U.S. Patent No. 9,767,992 filed September 19, 2017, the entirety of which is incorporated herein by reference.

[0168] The term "in-flight" refers to a novel chemical synthesis method based on decomposing incoming carbon-containing gaseous species, for example, species containing methane (CH4), by contacting particulate matter derived from such species. The decomposition as generally understood and referred to herein refers to the technical process of methane pyrolysis to produce elemental carbon, such as high-quality carbon black and hydrogen gas, free from problematic contamination by carbon monoxide and with minimal carbon dioxide emissions. The basic endothermic reaction that may occur within a microwave reactor to produce carbonaceous particles (100A) is given by Equation 7 below:

[0169] (7)

[0170] Carbon derived from the aforementioned decomposition process and / or similar or dissimilar processes can fuse together while dispersed in a gaseous phase called flight, thereby generating carbon-based particles, structures, substantially 2D graphene sheets, 3D aggregates and / or pathways defined therein, including the following:

[0171] An interconnected 3D aggregate (101B) of a multilayer graphene sheet (101C) and / or a single layer of graphene, as schematically illustrated in FIG. 1c, is fused together to form an open porous scaffold (102A) that promotes electrical conduction along and across the contacts of the graphene sheet (101C), which, as illustrated in FIG. 1b, has a stacking height (L c It may include and / or refer to 5 to 15 layers of few-layer graphene oriented in a stacked configuration having a vertical height referred to as ); and,

[0172] Any one or more of adjacent microstructures (107F) whose shape is interspersed or otherwise defined by interconnected 3D aggregates (101B); in some configurations, the interconnected 3D aggregates may be prepared to include one or more of single-layer graphene (SLG), few-layer graphene (FLG) defined as a range of 5 to 15 layers of graphene, or multi-layer graphene (MLG).

[0173] As previously described, multiple layers of interconnected 3D aggregates of graphene sheets (101B) are fused at right angles to each other to serve as a bonding material that allows for the removal of a type of intrinsic, self-supporting binder or a separate traditional binder material. This procedure is substantially different from conventional sintering or frittage as generally understood and referred to herein, which refers to a process of compressing and forming a solid mass of material by heat or pressure without melting the material to a liquefaction point where the material is bonded at a specific acute angle to each other.

[0174] A small number of layer graphene (FLG), defined herein as a range of 5 to 15 layers or sheets of graphene, is fused at an angle that is not flat compared to other FLG sheets, nucleates and / or grows obliquely, and self-assembles over time. Furthermore, process conditions can be adjusted to achieve the synthesis, nucleation and / or growth of carbon-based particles (100A), also referred to as multiple carbon-based particles, which completely fly off when in contact with other carbon-based materials or on the components and / or wall surfaces within the reaction chamber.

[0175] The electrical conductivity of the deposited carbon and / or carbon-based material can be adjusted by adding metal additives to the carbon in the first part of the deposition step or by varying the ratio of the various particles discussed. Other parameters and / or additions can be adjusted as part of the energy deposition process so that the energy level of the deposited carbon and / or carbon-based particles becomes one of the following:

[0176] Binding together; or,

[0177] Not tied together.

[0178] By nucleating and / or growing carbon-based particles (100A) directly in an atmospheric plasma-based vapor stream on a flight, support, or sacrificial substrate, several steps and components found in conventional batteries and battery manufacturing processes can be eliminated. Additionally, a significant amount of tuning and modulation capabilities may be possible or added to the discussed carbon and / or carbon-based materials.

[0179] For example, traditional batteries may use starting materials such as active materials, graphite, etc., which can be obtained as ready-made materials to be mixed into a slurry. In contrast, the carbon-based particles (100A) disclosed herein may enable the customization and / or adjustment of the material's properties in real time as the material is synthesized and / or deposited onto a substrate as part of a carbon or carbon-based material synthesis and / or deposition process. This capability represents a surprising, unexpected, and substantially advantageous starting point from what is currently available regarding the creation of carbon-based scaffold electrode materials in the field of secondary batteries.

[0180] The reactor and / or reactor design disclosed by Stowell et al. in U.S. Patent No. 9,767,992, filed September 19, 2017, “Microwave Chemical Processing Reactor”, can be adjusted, configured, and / or customized to control desired or unwanted nucleation sites on the inner surface of a reaction chamber exposed to carbonaceous gaseous feedstock species such as methane (CH4). The quality of the flying particles may be influenced by their solubility in the gaseous species, where, upon reaching a certain energy level, it is not conceivable that the carbon will decompose as described by thermal cracking, but rather flow to form a solid in the microwave reactor.

[0181] Adjustment for unwanted carbon accumulation on the reaction chamber walls

[0182] Furthermore, tuning of the disclosed reactor and related systems can be performed proactively, such as before the observation of undesirable process conditions, or retrospectively, such as after such conditions have been observed, to address issues related to carbonaceous microwave reactor clogging. For example, open surfaces, feed holes, hoses, piping, etc., may accumulate unwanted carbonaceous particulate material as a byproduct of the synthesis procedure performed to produce carbonaceous particles (100A). Microwave reactors may exhibit this tendency to experience clogging inside and / or along the orifice, due to the walls and other surfaces being exposed to carbon-containing species in the incoming gas that have carbon solubility. Consequently, unwanted growth is possible on the walls and / or outlet tubes of the reaction chamber. Over time, this growth can expand, ultimately obstructing the flow and blocking chemical reactions occurring within the reactor and / or reaction chamber. This phenomenon can be analogous to the wall accumulation of burned oil in exhaust pipes, high-performance, or racing internal combustion engines, where methane is used instead of burning fossil fuel-based gasoline, resulting in unwanted carbon deposition in the reaction chamber wells because the metal inside the reaction chamber has carbon solubility levels.

[0183] While methane is primarily used to produce carbon-based particles (100A), one or more of carbon-containing and / or hydrocarbon gases such as C2 or acetylene, or biogases such as C2H2, CH4, butane, natural gas, or those derived from the decomposition of biological materials, will likewise serve as carbon-containing sources.

[0184] The uncontrolled and unwanted carbon growth described within the exposed surface of a microwave reactor can be compared to that occurring within an internal combustion engine exhaust manifold, as opposed to the cylinder bore of an engine, where a plasma plume—such as hot, excited gases attempting to enter a plasma state—occurs at the beginning of the manifold and obstructs the flow of combustion gases and carbonaceous debris moving downward through the manifold, cross pipes, catalytic converters, and outlet pipes. Therefore, process conditions can be pre-tuned to regulate and accommodate potential carbon accumulation in a microwave reactor that relies on the presence of a plasma for hydrocarbon gas decomposition. Maintaining this plasma requires a specific set of conditions; otherwise, back pressure accumulation can destroy the plasma before plasma generation and subsequent ignition.

[0185] thermal reactor

[0186] In an alternative or additional to the synthesis of carbonaceous particles (100A) in a microwave reactor, structured carbon can be produced by thermally decomposing hydrocarbons by applying heat in a reactor such as a thermal reactor. An exemplary configuration may include exposing an incoming carbonaceous gas species, such as any one or more of the aforementioned hydrocarbons, to a heating element similar to the wire of a light bulb.

[0187] The heating element heats the inside of the reaction chamber where the incoming carbon-containing gas is ionized. Since there is insufficient oxygen to sustain combustion, the carbon-containing gas is not combusted but rather comes into contact with thermal radiation in the form of heat, causing it to ionize and induce nucleation of the components of the carbon-based particles (100A), ultimately synthesizing the carbon-based particles (100A) and / or similar carbon-based particles as a whole through nucleation. At least some of the observed nucleation of carbon-based particles in the thermal reactor may occur in the walls or the heating element itself. Nevertheless, particles can still form nuclei small enough to be broken down by the velocity of the flowing gas, where these particles are captured to aid in the formation of the carbon-based particles (100A).

[0188] The decomposed carbon can be used to generate multi-shell fullerene CNOs (carbon nano-onions), and / or other fullerenes, and smaller fragments of carbon having fullerene internal crystallography. When comparing the synthesis of carbon-based particles (100A) via microwave and thermal reactors, the following differences were observed:

[0189] Microwave reactors can provide tuning capabilities suitable for providing a wide range of carbon allotropes; on the other hand,

[0190] Thermal reactors tend to allow fine tuning of process parameters such as heat flow, temperature, etc., to meet the requirements of specific end-use applications of carbon-based particles (100A).

[0191] For example, thermal reactors are currently used to construct Li₂S electrochemical cell electrodes such as anodes and cathodes. Typical processing temperatures for producing carbonaceous particles (100A) and / or related carbonaceous aggregates are in the thousands of Kelvin range and, when compressed, have electrical conductivity greater than 500 S / m, greater than 5,000 S / m, or between 500 S / m and 20,000 S / m. Optimal performance was observed at 2,000–4,000 K.

[0192] Carbon-based Particles - Physical Properties & Implementation of Li-ion and Li-S Batteries

[0193] Any carbon-based structure illustrated in FIGS. 1a-1f can be incorporated into a secondary battery electrode, such as a lithium (Li) ion battery, as substantially disclosed by Lanning et al. in U.S. Patent Publication No. 2019 / 0173125, published June 6, 2019, “Lithium Ion Battery and Battery Materials,” the entirety of which is incorporated herein by reference. While the disclosed embodiment typically relates to the incorporation or injection of Li into the anode, the carbon-based system may be modified in a Li₂S system where micro-confinement of S is desirable for compatibility and integration with the cathode, particularly to mitigate unwanted polysulfide (PS) shuttle and cell self-discharge.

[0194] Fine particulate carbon included in or otherwise combined with carbon-based particles (100A) can be implemented as a structural and / or electrically conductive material in a Li-ion battery anode or cathode and can feature a hierarchical porous network (100F) having a wide distribution of pore sizes, also known as a multimodal pore size distribution. For example, the fine particulate carbon may include a multimodal distribution of pores in addition to or alternatively in an adjacent microstructure (107F), as illustrated in FIG. 1f, which at least partially further defines an open porous scaffold (102A) having one or more diffusion paths (109F). These pores may have sizes of 0.1 nm to 10 nm, 10 nm to 100 nm, 100 nm to 1 micron, and / or greater than 1 micron. The pore structure may include pores with a multimodal distribution of sizes, including smaller pores with sizes ranging from 1 nm to 4 nm and larger pores with sizes ranging from 30 to 50 nm. This multimodal distribution of pore sizes in carbon-based particles (100A) may be advantageous in the configuration of a Li₂S battery system, wherein the S-containing cathode of the Li₂S battery may be limited to pores (105F) having dimensions (103F) of less than about 1.5 nm or sizes ranging from 1 to 4 nm. Control of the saturation and crystallinity of S and / or generated S compounds in a carbon-based cathode containing larger pores or pathways in the 30 to 50 nm size range, or adjacent microstructures (107F) in pores larger than twice the size of the solvated lithium ion, may enable and / or promote rapid diffusion or mass transport of solvated Li ions in the cathode.

[0195] As previously introduced, lithium-sulfur batteries, abbreviated as Li-S batteries, are a type of rechargeable battery characterized by high specific energy. Li-S batteries may contain sulfur (S) infiltrated or injected to be trapped within pores (105F) along the exposed surface of a continuous microstructure (107F) of mesoporous particles (100E). Thus, when S infiltrates into an open porous scaffold (102A) and is incorporated into the cathode of a Li-S battery, it is deposited within the inner surface of carbonaceous particles (100A, 100E) and / or adjacent microstructures (107F) as illustrated in FIG. 1f and by the schematic diagram (100G) illustrated in FIG. 1g, which contains sulfur sulfide ions (S 2- It shows the intermediate steps related to the reduction to ).

[0196] Carbon-based particles - formed to solve polysulfide (PS) related problems

[0197] To address at least some of the problems associated with such polysulfide (PS) systems, carbon-based particles (100A) and a cathode active material form a meta-particle framework, wherein a cathode electroactive material, such as elemental sulfur capable of forming a PS compound (100G) as shown in FIG. 1g, is arranged within carbon pores / channels, such as within any one or more of adjacent microstructures (107F) as shown in FIG. 1f, which include pores (104F, 105F) and / or pathways (106F) and / or diffusion pathways (109F). S may be substantially contained within the adjacent microstructures (107F), for example, at a loading level representing 35-100% of the total weight / volume of the active material throughout the carbon-based particles (100A and / or 100E).

[0198] This type of organized particle framework can provide low-resistance electrical contact between an insulating cathode electroactive material, such as an S element, and a current collector, and supports Li-ion micro-confinement enhanced by the formation of Li-S compounds temporarily retained in adjacent microstructures (107F), such as pores (105F), which is beneficial to the overall capacity, thereby providing a structure with a relatively high exposed surface area that can control and directly assist in the migration of Li-ions that may eventually be related to current conduction in the battery electrode and / or system. The implementation of carbon-based particles (100A) can also benefit cathode as well as anode stability by capturing at least some of the polysulfides generated using customized structures such as those illustrated by adjacent microstructures (107F), thereby actively preventing unwanted migration to the anode through the electrolyte that causes unwanted parasitic chemical reactions associated with battery self-discharge.

[0199] Migration of polysulfide (PS) during use of Li₂S battery system

[0200] As previously mentioned, referring to the PS shuttle mechanism observed in Li₂S battery electrodes and / or systems, PS dissolves very well in the electrolyte. This triggers the shuttle mechanism, another characteristic of Li-S batteries. PS₂S₅₀ formed and dissolved at the cathode. n2 It diffuses into the Li anode and is reduced to Li2S2 and Li2S. PS species S formed at the cathode during discharge n 2- It dissolves in the electrolyte there. A concentration gradient toward the anode is created, causing PS to diffuse toward the anode. PS is distributed in the electrolyte stepwise. Subsequent higher-order PS species react with these compounds to form lower-order polysulfide S (n-X)It forms. This means that the desired chemical reaction of sulfur at the cathode also occurs at the anode in a partially uncontrolled manner, and here both chemical and electrochemical reactions can be considered, which has a negative effect on the overall cell characteristics.

[0201] When low-order PS species form near the anode, they diffuse into the cathode. When the battery discharges, these diffused species are further reduced to Li2S2 or Li2S. Consequently, cathode reactions occur either partially at the anode during discharge or, rather, through self-discharge of the cell. Both are undesirable effects that reduce capacity. In contrast, diffusion into the cathode during the charging process leads to the re-oxidation of PS species from lower to higher orders. These PS then diffuse back into the anode. This cycle is generally known as the shuttle mechanism, which can be very pronounced, making it possible for the battery to accept unlimited charge to chemically short-circuit. Generally, the shuttle mechanism causes loss of parasitic sulfur active material. This is because Li2S2 and Li2S are uncontrolledly separated outside the cathode region, ultimately significantly reducing the battery's cycling capability and service life. Additional aging mechanisms may include the non-uniform separation of Li2S2 and Li2S at the cathode or mechanical destruction of the cathode structure due to volume changes during battery reactions.

[0202] The pores of carbon-based particles trap sulfur and prevent PS shuttles to the anode.

[0203] To address the PS shuttleing phenomenon, any one or more of the adjacent microstructures (107F) of the carbonaceous particles (100A) at the cathode may provide regions formed with appropriate dimensions, such as pores (105F) having dimensions (103F) of less than 1.5 nm, to induce the formation of lower-order polysulfides such as S and Li2S, and thus higher-order soluble polysulfides, Li, where y is greater than 3, which facilitate Li shuttles such as anode loss. x Sy Prevents the formation of. As described in this specification, the structure of the particulate carbon and the cathode mixture of the material can be tuned during particulate carbon formation in a microwave plasma or thermal reactor. Additionally, cathode electroactive materials such as elemental sulfur, solubility, and crystallinity associated with Li phase formation can be confined / captured within the micro and / or mesoporous framework of the adjacent microstructure (107F) of the carbon-based particle (100A).

[0204] A multimodal distribution of pore sizes can represent structures with a high surface area and a large amount of small pores that are efficiently connected to a substrate and / or current collector through materials with structures having larger feature sizes, providing more conductive paths through the structure. Some non-limiting examples of such structures are fractal structures, dendrite structures, branched structures, and / or aggregate structures having interconnected channels of different sizes composed of pores and / or particles that are approximately cylindrical and / or spherical.

[0205] An exemplary particulate carbon material used in Li-ion or Li-S batteries described herein is described in U.S. Patent No. 9,997,334 under the designation “Seedless Particles Having Carbon Allotropes,” which is assigned to the same assignee as this application and incorporated herein by reference. The particulate carbon material may contain a graphene-based carbon material comprising a plurality of carbon assemblies, each carbon assembly having a plurality of carbon nanoparticles, each carbon nanoparticle comprising graphene, optionally comprising multi-walled spherical fullerenes, and optionally lacking seed particles, such as lacking nucleation particles. In some cases, the particulate carbon material is 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 other elements other than hydrogen in the carbon assemblies is greater than 99%. The intermediate size of the carbon assemblies is 1 micron to 50 microns, or 0.1 micron to 50 microns. The surface area of ​​the carbon aggregate is at least 10 m² when measured using the BET (Brunauer-Emmett-Teller) method with nitrogen as an adsorbent. 2 / g, or at least 50m 2 / g, or 10m 2 / g to 300m 2 / g or 50m 2 / g to 300m 2 / g. When compressed, the carbon aggregate has an electrical conductivity of greater than 500 S / m, or greater than 5,000 S / m, or between 500 S / m and 20,000 S / m.

[0206] Differences between carbon-based particles and existing technology

[0207] Conventional composite Li-ion or Li-S battery electrodes can be manufactured using polymer-based binders optimized to create a unique self-assembly morphology defined by an interconnected permeable conductive network and a slurry-cast mixture of active materials containing conductive additives, such as fine carbon black and graphite, for use in battery cathodes of specific aspect ratios. In conventional formulations or applications, additives and binders can be optimized to improve electrical conductivity, for example, by providing lower interfacial impedance, thereby offering improved power performance and transfer; however, they also exhibit parasitic mass, which inevitably reduces the specific, gravity, energy, and density required for high-performance battery applications currently demanded.

[0208] To minimize losses due to parasitic mass, such as those resulting from increased active and / or inactive ratios, and simultaneously enable faster access of the electrolyte to the entire surface of the electrode, the diffusion path (109F) can be reoriented to effectively shorten the length of the Li-ion diffusion path for charge transport. Hierarchical pores (101A) and / or open porous scaffolds (102A) can be created from carbon particles and / or active materials reduced to the nanometer scale. External specific surface area (SSA) is defined as the total surface area of ​​the material per unit mass, and the unit is m² 2 / kg or m 2 / g or solid or bulk volume (m 2 / m 3 or m -1The unit of is any one or more physical values ​​of currently disclosed carbon particles that can be used to determine the type and properties of the material. For example, the SSA of a sphere increases as the diameter decreases. However, as the particle size decreases to the nanometer size range, there are van der Waals forces of attraction that hinder dispersion and promote aggregation, which can increase cell impedance and decrease power performance.

[0209] Another approach to shortening the ion diffusion path with reference to the diffusion path (109F) illustrated in FIG. 1f is to uniquely manipulate the internal porosity of constituent carbon-based particles, such as those created by aggregates (101B), to create a continuous microstructure (107F). If the cavity is deeper than its width, the surface curvature can be called a pore. Consequently, this definition is excluded in densely packed particles where voids, such as intra-specific spaces or regions between adjacent particles, are created, as in the case of many nanostructured carbon materials with modified external surface areas or conventional slurry-cast electrodes.

[0210] In relation to engineering, regarding the synthesis, generation, formation, and / or growth of carbon-based particles (100A), substantially, whether through flight in the microwave-based reactor described above or layer-by-layer deposition in a thermal reactor, reactor process parameters can be adjusted to tune the size, geometry, and distribution of the hierarchical pores (101A) and / or adjacent microstructures (107F) within the carbon-based particles (100A). The hierarchical pores (101A) and / or continuous microstructures (107F) within the carbon-based particles (100A) can be customized to achieve performance figures that are particularly suitable for implementation in high-performance, high-speed current transfer devices such as supercapacitors.

[0211] As generally explained earlier, supercapacitors (SC), also known as ultracapacitors, are high-capacity capacitors that bridge the gap between electrolytic capacitors and rechargeable batteries, having a much higher capacitance value than other capacitors but a lower voltage limit. Typically, they store 10 to 100 times more energy per unit volume or mass than electrolytic capacitors, can accept and transfer charge much faster and more efficiently than batteries, and can withstand much more charge and discharge cycles than rechargeable batteries.

[0212] In many of the available off-the-shelf carbons used in early supercapacitor development efforts, there were worm-shaped narrow pores that acted as bottlenecks or problems when operating at high current densities and fast charge and discharge rates, as high electrons could struggle to flow internally or externally through such structures or pathways. Although the pore dimensions were fairly uniform and still adjustable to accommodate various length scales, the actual achievable performance was still self-limiting because it was based on structural problems inherent to worm-type narrow pores.

[0213] Compared to conventional porous materials having uniform pore dimensions tuned to a wide length scale, the 3D hierarchical porous material disclosed herein, such as illustrated by hierarchical pores (101A) and / or a continuous microstructure (107F) within carbon-based particles (100A), can be synthesized to have well-defined pore dimensions, such as a continuous microstructure (107F) including pores (104F, 105F), and / or paths (106F) and / or diffusion paths (109F) and topology, to overcome the disadvantages of conventional single-size pores and / or channels by creating multimodal pores and / or channels having the following dimensions and / or widths:

[0214] Meso(2 nm < d pore < 50 nm) pores;

[0215] Macro (d) shown in the micrograph (200) of FIG. 2 for minimizing diffusion resistance for mass transport pore > 50 nm) pore (201A); and,

[0216] Micro (d) for increasing surface area for active site dispersion and / or ion storage pore Capacitance related to the density and number of ions that can be stored within a given pore size, as indicated by the pore (202) with dimensions (103F) in FIG. 1f.

[0217] Although a simple linear correlation between surface area and capacitance has not been experimentally established, carbon-based particles (100A) provide different optimal micropore size distributions and / or configurations for each intended end-use and corresponding voltage window. To optimize capacitance performance, carbon-based particles (100A) can be synthesized with a very narrow pore size distribution (PSD); and larger pores are preferred as the desired or required voltage increases. Nevertheless, supercapacitors of current state-of-the-art technology have provided a path to engineer the 3D hierarchical materials disclosed herein for specific end-use applications.

[0218] In supercapacitors, capacitance and power performance are primarily governed by, for example, the following:

[0219] Surface area of ​​the work wall;

[0220] Size of the workmanship; and

[0221] Interconnectivity of pore channels affecting electric double layer performance.

[0222] In contrast, since Li-ion and / or Li-S storage batteries undergo Faraday reduction / oxidation reactions within the active material, many of the Li-ion transport features of supercapacitors, such as efficiently oriented and / or shortened Li-ion diffusion pathways, may be required. Nevertheless, in all applications including supercapacitors and traditional Li-ion or Li-S secondary batteries, 3D nanocarbon-based frameworks / architectures, such as those defined as open porous scaffolds (102A), can provide continuous electrical conduction pathways, for example, across and along electrically conductive interconnected aggregates of graphene sheets (101B) with high-load active materials having high area and volume specific capacity.

[0223] Carbon-based particles used as cathode-forming materials

[0224] To address common problems associated with relatively low electrical and ionic conductivity, volume expansion, and polysulfide (PS) dissolution in current Li₂S cathode electrode designs, carbon-based particles (100A) have hierarchical pores (101A) and / or a continuous microstructure (107F) formed internally to define an open porous scaffold (102A), which includes pores (105F) having a microporous texture with dimensions (103F) such as cavities of approximately 1.5 nm or less than 1-4 nm suitable for trapping elemental sulfur and / or Li₂S-related compounds. The open porous scaffold (102A) provides a host scaffold-type structure that manages S expansion to ensure electron conduction across sulfur-carbon (SC) interfaces, such as contact and / or interfacial regions of S and C within the pores (105F), by, for example, customized in situ nitrogen (N) doping of carbon (C) within the reactor while trapping sulfur. Constricting S within a nanometer (nm) scale cavity, such as a pore (105F) having a microporous texture (103F), changes both advantageously:

[0225] Equilibrium saturation equal to the solubility product; and,

[0226] When dissociating Li₂S compounds, etc., within a microporous texture or pore (105F) having dimensions (103F) without an external driving force required to control the crystalline behavior of S and unwanted PS migration to the anode electrode, S maintains confinement that may be necessary for desirable electrical conductivity.

[0227] Consequently, the dimensions (103F) of the pores (105F) do not require a separator that attempts to hinder polysulfide (PS) diffusion while simultaneously having a negative effect on the cell impedance, such as the effective resistance of an electrical circuit or component to alternating current resulting from the combined effects of ohmic resistance, reactance, and polarization. By using optimal carbon for the micro-confinement and non-optimal multimodal, the carbon-based particles (100A) exhibit the operation of the micro-confinement principle in a properly optimized structure by using optimal carbon for the continuous microstructure (107F) containing elements S, Li, and / or Li₂S, which refer to the pores (104F, 102F, and / or 103F) or (alternatively) a bimodal pore distribution.

[0228] This optimized structure includes integration with aggregates (101B), which can be formulated to include parallel stacked graphene layers, such as those produced from graphite with strong (002) dimensions to random few-layer (FL) graphene with nano-sized pores with low (002) dimensions. FIGS. 1h and 1i show the systematic intercalation of Li ions in the carbon lattice and structure, located within the individual graphene layer cell of FIG. 1h and between adjacent and parallel graphene layers of FIG. 1i. The configuration illustrated in FIG. 1i may include multiple stages including stages 1 through 3, each state representing different dimensions and spacing levels of graphite layer planes to generate a theoretical specific capacity of about 372 mAh / g at the cathode.

[0229] FIG. 2 illustrates an evolution beyond the conventional adjacent stacked FL graphene layers shown in stages 1 through 3 of FIG. 1i, wherein a cavity is formed by extending in the depth direction into several of the adjacent stacked FL graphene layers, each layer having an adjustable D-spacing in the range of approximately 3.34 Å to 4.0 Å, or 3 Å to 20 Å. Thus, Li ions can not only be intercalated between adjacent graphene layers but can also form a layer on the exposed surface of the cavity, which is also referred to as a nanopore to yield a specific capacity range exceeding 750 mAh / g. Collectively, an exemplary enlarged section of a 3D self-assembled binder-free carbon-based particle can be combined to form a carbon-based network, lattice, scaffold, or particle that may include any one or more of the carbon-based structures shown in FIG. 1a through 1f, depending on some implementation. The carbon-based network may include any one or more of a plurality of macropores or micropores (202).

[0230] The carbon-based particles (100A) also provide the ability to effectively load or inject elemental Li, such as that provided from molten Li metal or its vapor derivatives, into the carbon scaffold (300) shown in FIG. 3. The carbon scaffold (300) can be produced in a reactor by one of the following:

[0231] Layer-by-layer deposition of multiple carbon-based particles (100A) by a slurry case method; or,

[0232] By a continuous sequence of plasma spray torch groups illustrated by the plasma spray torch system (400B) of Fig. 4b containing sulfur such as elemental sulfur.

[0233] For Li₂S battery performance to reliably outperform conventional Li-ion batteries, industrially scalable technology must achieve high S loadings, such as >70% sulfur per unit volume, relative to all additives and components of a given cathode template while maintaining the basic specific amount of S active material. Attempts to incorporate S into the cathode host, such as performing one or more of electrolysis, wet chemistry, simple mixing, ball milling, spray coating, and cathode liquid independently or in combination, have not fully incorporated S as desired, nor are they economically scalable or manufacturable.

[0234] Unlike melt infiltration, where small pores are thermodynamically inaccessible, the synthetic approach disclosed herein may utilize isothermal vapor technology introduced and reacted substantially at atmospheric pressure, where the high surface free energy of the nanoscale pores or surfaces induces spontaneous nucleation of the sulfur-containing liquid until an conformal coating of sulfur and / or lithium-containing condensate reaches the inner facing surface of the hierarchical pores (101A) and / or adjacent microstructures (107F). Essentially, the unique vapor injection process injects sulfur into the micropores as well as the surfaces, such as one or more of the diffusion paths (109F) in the hierarchical pores (101A) and / or adjacent microstructures (107F) and / or pores (104F, 105F) and / or paths (106F) and / or the core of the carbonaceous particles (100A).

[0235] Carbon-based particles used to create electrically conductive scaffolds

[0236] Carbon-based particles (100A) can be manufactured in any number of ways using both known and novel techniques disclosed herein, including the following:

[0237] Slurry-casting refers to an existing metalworking, manufacturing, and / or fabrication technique in which a liquid material is poured into a mold containing a hollow cavity of a desired shape and allowed to solidify; or

[0238] A plasma spray-torch system (400B) as shown in FIG. 4b can be used to perform layer-by-layer deposition to gradually grow carbon-based particles (100A).

[0239] The carbon scaffold (300) illustrated in FIG. 3 can be produced in a graded manner using the technology described above or any other known or novel manufacturing technology. Control of the electrical gradient may result in a carbon scaffold (300) having varying electrical conductivity, as indicated at least partially by any one or more of the electrical gradient and ion conductivity gradient described below:

[0240] The electrical gradient can be defined by a graphene sheet (101B) that is substantially fused at a right angle to form an open porous scaffold (102A), wherein electrical conduction occurs along and across the contacts of the graphene sheet (101B); and,

[0241] An ion conductivity gradient, such as Li ion transport, movement, or migration through hierarchical pores (101A) and adjacent microstructures (107F), can be benefited in a specific configuration of carbon-based particles (100) by effectively shortening the diffusion path (109F) over the entire thickness of the carbon scaffold (300B) in the vertical height direction A as shown in FIG. 3b, so that Li ions intercalated between adjacent few-layer graphene sheets, such as graphene sheets (101B), may escape and migrate toward the liquid electrolyte surrounding the carbon scaffold (300B) in the path to cathode-cured electrochemical cell discharge-charge cycling.

[0242] Throughout the embodiments disclosed herein, reference has been made to various forms of carbon synthesized in flight within a reactor to produce graphene sheets (101B), which are interconnected and conduct electricity along contacts and may differ in shape, size, location, orientation, and / or structure. These variations may be influenced by differences in the specific types of carbon allotrope(s) and crystallinity used to produce the electrically conductive interconnected aggregates of the graphene sheets (101B). Crystallinity refers to the degree of structural order of a solid. In a crystal, atoms or molecules are arranged regularly and periodically. Therefore, crystallinity has a significant impact on hardness, density, transparency, and diffusion.

[0243] Accordingly, carbon-based particles (100) can be produced in the form of an organized scaffold, such as a carbon-based scaffold, outside the reactor or during a post-processing activity that occurs outside of the primary synthesis inside the reactor.

[0244] Plasma processing and / or plasma-based processing may be carried out in a reactor disclosed in U.S. Patent No. 9,767,992 issued on September 19, 2017, by Stowell, et al., titled “Microwave Chemical Processing Reactor,” wherein a feed gas is used to generate plasma in a plasma zone to convert process input materials, such as methane and / or other suitable hydrocarbons in the gaseous phase, into components separated in a reaction zone to promote the in-flight synthesis of carbonaceous materials.

[0245] As an alternative to synthesis by a microwave reactor as described above, thermal energy may be sequentially transferred to or near a carbon-containing feedstock material supplied in a gaseous state on a sacrificial substrate (306) of a carbon scaffold (300) shown in FIG. 3 to deposit multiple layers of carbon-based particles (100A) by, for example, a plasma spray torch system (400B) shown in FIG. 4b. These particles may be fused together in a flying microwave reactor or deposited in a thermal reactor in a controlled manner to achieve various concentration levels of carbon-based particles (100A), thereby achieving differential electrical conductivity proportional to the concentration level of carbon-based particles (100A) within the carbon scaffold (300). This procedure can be used to formulate porous carbon-based electrode structures, such as carbon scaffolds (300), which have a high degree of tunability such as electrical conductivity and ion transport, while eliminating many production steps and maintaining the existing appearance.

[0246] The open porous scaffold (102A) may be produced with an open cell structure so that a liquid electrolyte can easily penetrate into various pores, such as any one or more of the paths, voids, etc., of the adjacent microstructure (107F) within it. The skeletal portion of the open porous scaffold (102A) may be referred to as a matrix or frame, and while pores such as the hierarchical pores (101A) and / or adjacent microstructures (107F) may be penetrated by fluid, liquid, or gas, the skeletal material is generally formed of a solid material.

[0247] Porosity of carbon-based particles

[0248] A porous medium, such as carbonaceous particles (100A), can be characterized by porosity. Other properties of the medium, such as permeability, tensile strength, electrical conductivity, and torsion, can be derived from the porosity and pore structure of the medium, as well as from the respective properties of the solid matrix and fluid components interspersed within it. Carbonaceous particles (100A) having a continuous microstructure (107F) interspersed throughout the interior can be produced outside the reactor to achieve a desirable level of porosity that aids in Li-ion diffusion. In relation to this Li-ion diffusion, a graphene sheet (101B) facilitates electron conduction along contact points while allowing electrons to recombine with the cation Li-ions at reaction sites.

[0249] In relation to the porosity and tortuosity of the open porous scaffold (102A) of the carbon-based particle (100A), it can be likened to beads in a glass jar. In this example, porosity refers to the gaps between the marbles that allow the liquid electrolyte to penetrate into the void spaces between the marbles, similar to the adjacent microstructure (107F) that defines the diffusion path (109F) within the carbon-based particle (100A). By allowing the electrolyte to penetrate into the individual graphene sheets, as well as into the cracks between the graphene sheets (101B), as illustrated in FIG. 1c, it can be like Swiss cheese itself. In this example and others, the relative shortening of the diffusion path (109F) refers to the time it takes for Li ions to penetrate inside by capillary action to come into contact with an active substance, such as S, trapped within the pore (105F), for example. The diffusion path (109F) accommodates convenient and rapid penetration and diffusion of the electrolyte into the carbon-based particles (100A) that may contain Li ions, which can then be further grown or synthesized to produce a carbon scaffold (300) having differential electrical conductivity.

[0250] The shortening of the diffusion path (109F) means a shortening of the diffusion length of the movement of Li ions within the open porous scaffold (102A) of the carbon scaffold (300), and the active material itself, such as S, is not confined within the pores (105F) of the adjacent microstructure (107F). This contrasts with existing techniques that shorten the diffusion length of the active material by making the thickness of the active material thinner or smaller. The diffusion path (109F) within the continuous microstructure (107F) can act as a Li ion buffer reservoir by controlling the flow and / or transport of Li ions, and can provide a more free flow structure for Li ion transport that may be advantageous for Li ion confinement by reacting with Li ion transport during the electrochemical cell charge-discharge cycle with S coated on the exposed carbon surface of the pores (105). Transport of Li ions through the diffusion path (109F) in the general direction shown in Fig. 1f can occur in the liquid electrolyte that is initially injected and captured within the open porous scaffold (102A), where this injection of the electrolyte occurs before the use of the circulating carbon scaffold (300) in the discharge charge cycle.

[0251] There are examples in which the initial diffusion and distribution of a liquid electrolyte in an open porous scaffold (102A) of carbon-based particles (100A) is allowed to fill and occupy the hierarchical pores (101A) and / or adjacent microstructures (107F) before using the carbon scaffold (300) synthesized or produced by layer-to-layer deposition of carbon-based particles (100A). Vacuum or air may also be used to fill the hierarchical pores (101A) and / or adjacent microstructures (107F), which may allow or assist in wetting the electrolyte into the carbon-containing exposed surfaces within the open porous scaffold (102A).

[0252] Li ions are bounced from one location to another by a chain reaction similar to the impact of a Newton ball, where a force transfer occurs in which one strike causes another ball to move. Similarly, although each Li ion travels a relatively short distance, a large number of Li ions can be moved from the aggregate through this type of chain reaction as described. The degree of individual Li ion movement may be influenced by the amount of Li ions supplied to the carbon scaffold (300B) via capillary injection into an open porous scaffold (102A), which may be a crystallographic arrangement of Li ions and / or particles within, around, or inside the aggregate of the graphene sheet (101B).

[0253] Electrochemical cell anode or cathode created from a carbon scaffold

[0254] The carbon scaffold (300) illustrated in FIG. 3 can be incorporated into battery or supercapacitor applications, including battery types such as Li-ion batteries and Li-S batteries. The carbon scaffold (300) can be incorporated into the anode or cathode for Li-ion and Li-S battery systems, but it is necessary to form a continuous microstructure (107F) to trap S in the pores (105F) or elsewhere to accommodate the generation and trapping of polysulfide (PS) and control of PS migration. An exemplary battery system may include an electrochemical cell configured to supply power to the system. The electrochemical cell may include a cathode containing a cathode active material, a cathode containing a cathode active material, a porous separator placed between the anode and the cathode, and an electrolyte in ion contact with the anode active material and the cathode active material.

[0255] The anode and cathode may include an electrically conductive sacrificial substrate (306), and since the first layer is deposited thereon as a first continuous film having a first concentration of carbon-based particles (100A) as shown in FIG. 3 as carbon-based particles (302), a redundant description thereof is omitted.

[0256] A porous arrangement formed in a carbon scaffold (300) defined by carbon-based particles (302), which is synonymous with multiple carbon-based particles (100A) connected together and smaller carbon particles (304) scattered throughout the carbon scaffold (300), and is used interchangeably. The arrangement of the carbon scaffold (300) accommodates an electrolyte dispersed therein for Li ion transport through interconnected hierarchical pores (101A) and / or adjacent microstructures (107F) defining one or more channels similar to individual carbon-based particles (100A and / or 302), comprising:

[0257] A microporous framework defined with dimensions > 50 nm (101F) providing a tunable Li ion conduit;

[0258] Mesoporous channels defined by dimensions of about 20 nm to about 50 nm (101F), generally defined according to IUPAC nomenclature and referred to as mesopores or mesoporous, which act as Li-ion highways for rapid Li-ion transport within; and

[0259] Microporous texture defined by dimensions < 4 nm (103F) for charge acceptance and / or active material confinement.

[0260] A first layer comprising carbon-based particles (100A and / or 302) of a first concentration may be configured to exhibit an electrical conductivity in the range of 500 S / m to 20,000 S / m. A second or any subsequent layer may be deposited on the first or any preceding layer. The second layer may comprise a second continuous film formed by carbon-based particles (100A and / or 302) of a second concentration in contact with each other to produce a second electrical conductivity in the range of 0 S / m to 500 S / m, or otherwise lower than the first electrical conductivity.

[0261] A carbon scaffold (300) may be prepared for subsequent Li infiltration, referred herein as pre-lithiated, and later injected into a Li ion liquid solution via capillary action to produce a lithiated carbon scaffold (400A) as illustrated in FIG. 4a. Film layers (406A, 408A, 410A, 412A) having a thickness defined in the vertical direction extending from each current collector may be synthesized in flight in a microwave reactor or deposited layer by layer inside or outside a thermal reactor. The film layers (406A, 408A, 410A, 412A) have varying electrical conductivity in the vertical direction, ranging from high electrical conductivity as in film layer (406A), which may be a sacrificial and / or electrically conductive substrate, to low electrical conductivity as in film layer (412A). In an exemplary configuration, each layer of the film layers (406A, 408A, 410A, 412A) may be produced with a defined and progressively decreasing concentration of carbon-based particles (302) to achieve a specific electrical resistance value as follows:

[0262] The film layer (406A) is suitable for high electrical conductivity < 1,000 It is produced with carbon-based particles (302) of a relatively high definition concentration that helps with low Li ion transport and low electrical resistance.

[0263] The film layer (408A, 410A) is produced by systematically reducing electrical conductivity by engineering carbon-based particles (302) to exhibit desirable interfacial surface tension, thereby promoting the wetting of the carbon surface exposed to molten Li metal; and

[0264] The film layer (412A) is suitable for high electrical resistance > 1,000 - 10,000 It is produced with carbon-based particles (302) of a relatively low definition concentration that helps with high Li ion transport and high electrical resistance.

[0265] Various electrical conductivity may be at least partially proportional to the interfacial surface tension of the Li-ion solution infiltrated into the porous array of the open porous scaffold. Infiltration of the Li-ion solution may be performed via capillary injection designed to promote wetting of the surface of the open porous scaffold (102A) exposed to the Li-ion solution. As illustrated in FIG. 1f, the diffusion path (109F) ensures that deposition and stripping behaviors associated with one or more redox reactions occurring within the carbon-based particles (100A and / or 302B) are uniform. The electroactive material may be present in the pores (105F) of the adjacent microstructure (107F) when used to form the open porous scaffold (102A), which itself may be incorporated into any one or more of the anode and cathode. In some embodiments, the adjacent microstructure (107F) may be formed of, or otherwise contain, a single-layer graphene (SLG) comprising 1 to 10 graphene planes as illustrated in FIG. 1c and / or as a multilayer aggregate (101B) of graphene sheets (101C) illustrated in FIG. 1b. The group of graphene sheets (101C) may be positioned in an orientation substantially aligned along the vertical axis and may be fused together at substantially orthogonal angles. The anode active material or cathode active material has a specific surface area of ​​about 500 m² when measured in a dry state. 2 / g to 2,675 m 2It may be / g and may include a graphene material suitable for lithiation, and the graphene material includes pre-lithiated graphene sheets, pristine graphene, graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide, graphene iodide, graphene hydrogenate, graphene nitrate, boron-doped graphene, nitrogen-doped graphene, chemically functionalized graphene, physically or chemically activated or etched versions thereof, conductive polymer-coated or grafted versions, and / or combinations thereof.

[0266] In any one or more of the examples discussed in relation to the lithiated carbon scaffold (400A), electrically conductive interconnected aggregates of graphene sheets (101B) are sintered together to form an open porous scaffold independent of the binder, but alternative examples exist in which a binder is used. Configurations with or without a binder may each include an open porous scaffold (102A) that acts or serves as an active lithium intercalating structure having a specific capacity of about 744 to 1,116 mAh / g or more. Additionally, examples include the preparation of graphene sheets (101B) using chemically functionalized graphene, comprising surface functionalization thereof, comprising imparting to the open porous scaffold (102A) a functional group selected from quinone, hydroquinone, quaternary aromatic amine, mercaptan, disulfide, sulfonate (-SO3), transition metal oxide, transition metal sulfide, other similar compounds, or combinations thereof.

[0267] The current collector illustrated in FIG. 4a is, for example, at least partially foam-based or foam-derived and may be selected from any one or more of metal foam, metal web, metal screen, perforated metal, sheet-based 3D structure, metal fiber mat, metal nanowire mat, conductive polymer nanofiber mat, conductive polymer foam, conductive polymer coated fiber foam, carbon foam, graphite foam, carbon aerogel, carbon zerogel, graphene foam, graphene oxide foam, reduced graphene oxide foam, carbon fiber foam, graphite fiber foam, exfoliated graphite foam, and combinations thereof.

[0268] The electrically conductive or insulating material of the anode or cathode, referred herein as the active material, may comprise any one or more of nanodisks, nanoplates, nano-fullerenes, CNOs (carbon nano-onions), nano-coatings, or nanosheets of inorganic materials selected from the following:

[0269] Bismuth selenide or bismuth telluride,

[0270] Transition metal dichalcogenides or trichalcogenides,

[0271] Sulfides, selenides, or tellurides of transition metals;

[0272] Boron nitride, or

[0273] A combination of these containing molten Li metal interspersed therein to provide a source of Li ions upon dissociation during a normal electrochemical cell discharge-charge cycle.

[0274] Nanodisks, nanoplates, nanocoatings, or nanosheets may have a thickness of less than 100 nm. In other examples, nanoplates may have a thickness of less than 10 nm and / or a length, width, or diameter of less than 5 µm.

[0275] Production of anodes or cathodes generated from carbon structures

[0276] An exemplary process for producing a three-dimensional (3D) carbon-based electrode, such as one produced from a lithiated carbon scaffold (400A), may include deposition from one or more plasma-based thermal reactors or torches, wherein thermal energy is propagated through a plasma and / or feedstock material supplied in a gaseous state so that carbon-based particles (100A or 400A) form a first continuous film layer, such as the layer (406A) shown in FIG. 4a, on a substrate, wherein the first continuous film layer is characterized by first electrical conductivity. Each carbon-based particle comprises an electrically conductive three-dimensional (3D) aggregate or an aggregate of a graphene sheet (101B). The aggregates are orthogonally fused together to form an open porous scaffold (102A) to facilitate electrical conduction along and across the contact points of the graphene sheet.

[0277] A porous array formed in an open porous scaffold (102A), wherein the porous array helps to accommodate an electrolyte dispersed within for Li-ion transport through interconnected pores, such as hierarchical pores (101A) and / or adjacent microstructures (107F), which define diffusion paths (109F). The first continuous film layer has an average thickness of approximately 100-200 µm or less. In one example, a binder material is combined with a graphene sheet (101B) to hold the graphene sheet (101B) in a desired position to impart structure to the open porous scaffold (102A). The binder may be a thermosetting resin or a polymerizable monomer, or may comprise the same, wherein the resin curing or polymerization of the polymerizable monomer forms a solid resin or polymer with the help of heat, radiation, an initiator, a catalyst, or a combination thereof. The binder can initially be a polymer, coal tar pitch, petroleum pitch, mesalis pitch, or organic precursor material, and is later thermally converted into a carbon material.

[0278] An additional amount of carbon-based particles (100A) is deposited on a first adjacent film layer to form a second adjacent film layer thereon, the second adjacent film layer having a second electrical conductivity lower than the first electrical conductivity, located closer to the electrolyte (414A) and farther from a current collector which may be a sacrificial substrate. A Li-ion solution can penetrate into an open porous support (102A) by capillary injection and react with exposed carbon on the surface to promote Li-ion dissociation and current supply, wherein the exposed carbon on the open porous support is about 100 m 2 It can include a surface area larger than / gm.

[0279] Carbon-based particles (100A) and / or lithiated carbon scaffolds (400A) may be synthesized in flight in a microwave reactor or deposited in a bottom-up manner by reference to layer-by-layer deposition or growth within a thermal reactor, then cast through a liquid slurry and subsequently dried to form a carbon-based electrode suitable for implementation or incorporation within a Li-ion battery. In some examples, this slurry may contain a chemical binder and conductive graphite along with electrochemically active intrinsic carbon.

[0280] The term hierarchical refers to an arrangement of items indicated as being above, below, or at the same level as each other. Here, carbon-based particles (100A) and / or lithiated carbon scaffolds (400A) can be grown by layer-by-layer deposition in a thermal reactor to create one or more grades, as indicated by film layers (406A to 412A) of conductive particles (100A, 302B and / or 402A), which refer to a conductive gradient across the entire thickness of the lithiated carbon scaffold (400A), ionic, referring to a diffusion path (109F), and electrically generated by specific control of the contacts of the graphene sheet (101B). The adjustment of each individually deposited layer (406A to 412A) results in a relatively higher electrical conductivity at the current collector interface and a progressively lower electrical conductivity moving outward from there.

[0281] Graphene sheets (101B) within carbon-based particles (100A) can act as electrical conductors by serving as active Li intercalating structures and conducting current through contacts and / or regions, thereby providing a source for the specific capacity of an anode electrode from 744 to 1,116 mAh / g, which is 2 to 3 times that is available in a conventional graphite anode of, for example, 372 mAh / g. Consequently, interconnected 3D bundles of graphene sheets (102) within carbon-based particles (100A) can be considered as nanoscale electrodes that simultaneously enable a relatively high volume fraction of electrolyte active material along with efficient 3D interpenetration, ionic, and electronic pathways.

[0282] This unique 3D structure of the carbon-based particle (100A) enables both the storage of charge on the exposed surface through capacitive charge storage for desirable high power transfer compared to existing applications, and also the provision of Faraday redox ions within the bulk for desirable high electrical energy storage. As is generally understood and mentioned herein, redox represents a reduction-oxidation reaction, where the oxidation state of an atom changes, including electron transport between chemical species, and most commonly one species undergoes oxidation and another undergoes reduction.

[0283] The term "Faradaic" as generally understood and referred to herein refers to a non-uniform charge-transfer reaction occurring on the surface of an electrode made of and / or otherwise incorporated with carbon-based particles (100A). For example, a pseudocapacitor stores electrical energy in a Faradaic manner through the transport of electron charges between the electrode and the electrolyte. This is achieved through electroadsorption, redox reactions, and intercalation processes referred to as pseudocapacitance.

[0284] Roll-to-roll process for producing electrochemical cell electrodes generated from carbon scaffolds

[0285] In relation to manufacturing, the lithiated carbon scaffold (400A) can be manufactured to mass-produce and / or construct electrochemical cell electrodes, such as cathodes and / or anodes, by sequentially depositing a concentration of carbon-based particles (100A and / or 100E) onto a moving substrate, such as a current collector, via a roll-to-roll (R2R) production method, such as the layers (406A to 412A) shown in FIG. 4a. By directly incorporating the 3D carbon scaffold structure in a microwave reactor, similar to a conventional plasma spraying process, electrode films can be continuously produced without toxic solvents and binders used in the slurry casting process for battery electrodes. Thus, battery electrodes using the lithiated carbon scaffold (400A) can be more easily created by controlling the electrical, ionic, and chemical concentration gradients due to the layer-by-layer, sequential particle deposition capabilities of the plasma spraying type process; and specific elements, such as dopants, may be introduced at other stages within the plasma deposition process.

[0286] Additionally, due to the pores (105F) and / or continuous microstructure (107F) scattered throughout the carbon-based particles (100A), the lithiated carbon scaffold (400A) can be manufactured by gravimetric methods by referring to a series of methods used in the field of analytical chemistry for quantitative measurement of analytes based on mass superior to known devices. That is, the carbon-based particles (100A) having pores and / or voids defined throughout the 3D bundle of graphene sheets (102) and / or conductive carbon particles (104) can be lighter than a comparable battery electrode without a mesoporous structure containing various pores and / or voids.

[0287] Carbon-based particles (100) may feature a ratio of active material to inert material that is superior to that of conventional technology in that a larger amount of active material is available and prepared for electrical conductivity compared to inert and / or structural reinforcements. These structural reinforcements are involved in defining the general structure of the carbon-based particles (100A) but may or may not be involved in the electrically conductive interconnected aggregation of the graphene sheets (101B). Thus, due to the high ratio of active material to inert material, the carbon-based particles (100A) can not only exhibit superior electrical conductivity characteristics compared to conventional batteries but can also be much lighter than these conventional batteries, as carbon can be used to replace traditionally used heavy metals. Therefore, the carbon-based particles (100A) may be particularly suitable for demanding end-use applications that can benefit from relatively light weight, such as automobiles and light trucks.

[0288] Carbon-based particles (100A) can be generated to rely on electrically conductive interconnected aggregates of graphene sheets (101B) to obtain a penetration threshold by referring to the mathematical concept of penetration theory, which describes the formation of long-range connections in random systems. Below the threshold, no large connected components exist, but above the threshold, there are large components of the system size. Thus, 3D bundles of electrically conductive interconnected aggregates of graphene sheets (101B) can conduct electricity from a current collector toward an electrolyte (414A), as illustrated in FIG. 4a.

[0289] Roll-to-Roll (R2R) Plasma Spray Torch Deposition System

[0290] As a variation of the present disclosed atmospheric MW plasma reactor used to generate particle-based outputs including integrated continuous 3D hierarchical carbon scaffold films, a similar carbon-based structure illustrated by an R2R (roll-to-roll) system (400B) can be produced using a spray torch configuration. Using a plasma torch, similar to a waveguide reactor, the material can be initially formulationd and then accelerated to an impact zone on the substrate surface where it can move or stop. Each zone of the R2R process can provide unique control of integration, such as heterogeneous mixed-phase or composite material synthesis, formulation, integration, and densification.

[0291] A plasma torch can be used to deposit carbon-based particles onto a continuously moving substrate to enable additional type process control, ranging from the location of the high-temperature plasma jet depositing the carbon-based particles to the location beyond the plasma afterglow region to the impact zone of the substrate. Various properties such as defect density and residual stress can be controlled through the control of film layer deposition thickness, chemical and thermal gradients, phase transformations, and anisotropy. For the fabrication of electrochemical cell electrodes, an atmospheric pressure MW plasma torch can produce formulations and integrated continuous 3D graphene films without the use of toxic solvents such as NMP and / or binders according to conventional slurry casting processes. Furthermore, the plasma torch can be used to create integrated electrode / current collector film structures for enhanced performance at reduced cost.

[0292] FIG. 4b illustrates a roll-to-roll (R2R) system (400b) using an exemplary array of a group (444B) of plasma spray torches (422B to 428B), such as 422B, 424B, 426B, and / or 428B, all of which are configured to perform layer-by-layer deposition, referred to as growing in a different way, to progressively manufacture the carbon-based scaffold (300B) and / or a variation thereof shown in FIG. 3b. A group (444B) of plasma spray torches (414B to 420B) is oriented in a continuous order on an R2R processing device (440B), which may include wheels and / or rollers (434B and 439B) configured to rotate in the same direction (430B and 432B), and may result in a translational forward motion (436B) of a sacrificial layer (402B) on which a layer (442B) of carbon scaffold (436B) can be deposited in a layer-by-layer manner, thereby achieving a differential electrical conductivity gradient proportional to the concentration level of carbon-based particles (100A) contained per unit volume area in each progressively deposited layer, such as film layers (406A-412A).

[0293] This deposition may include positioning a group (444B) of plasma spray torches (414B to 420B) as illustrated in FIG. 4b, and initially, in the direction of forward motion (436B), the spray torch (414B) extends the farthest downward from a feedstock supply line (412B) toward the sacrificial layer (404B), which is positioned to spray a carbon-based material (422B) to deposit an initial layer (404B) which may be illustrated as an intermediate layer (406A) in FIG. 4a, etc., on a carbon support (300B) on a sacrificial layer (402B). The initial layer (404B) can be deposited to achieve the highest conductivity value, and each of the subsequent layers (406B to 410B) features a proportionally less dense dispersion of carbonaceous particles (100A) constituting the carbonaceous scaffold (300B) to achieve a differential electrical gradient for the layer (442B).

[0294] That is, the plasma spray torches (414B to 420B) can be oriented to gradually decrease or otherwise change their height as shown in FIG. 4b, so that each spray torch of the group (444B) can be adjusted to spray a carbon-based feedstock material supplied by the feedstock supply line (412B) into the respective sprays (422B to 428B). Thus, battery electrodes can be more easily created with controlled electric, ionic, and chemical concentration gradients due to the layer-by-layer, sequential deposition described herein by connecting to the plasma spray-torch system (400B) which exhibits the desirable features of a plasma spray type process; and specific elements or additional components can also be introduced at other stages within the plasma-based spray deposition process described by the plasma spray torch system (400B). Such control can be extended to the tunability of the plasma spray-torch system (400B) to achieve any one or more target electric field and / or electromagnetic field characteristics of the layers (442B).

[0295] A group of plasma spray torches (414B to 420B) (444B) may use plasma-based thermally enhanced carbon spray technology to provide a carbon coating process in which a molten or heated material is sprayed onto a surface. The feedstock, which is a coating precursor, is heated by electrical, plasma or arc or chemical means such as combustion and / or flame.

[0296] Thermal atomization by a plasma atomizing torch (414B to 420B) can provide thick coatings ranging in thickness from 20 µm to several mm, depending on the process and feedstock, over a wide area at a high deposition rate compared to other coating processes such as electroplating, physical and chemical vapor deposition. Coating materials that can be used for thermal atomization include metals, alloys, ceramics, plastics, and composites. They are fed in powder or wire form, heated to a molten or semi-molten state, and accelerated toward a substrate in the form of µm-sized particles. Combustion or electric arc discharge is typically used as an energy source for thermal atomization. The resulting coating is formed by the accumulation of numerous atomized particles. Since the surface is not heated significantly, flammable materials can be coated.

[0297] Coating quality is generally evaluated by measuring porosity, oxide content, macro and microhardness, bond strength, and surface roughness. In general, coating quality increases with increasing particle speed.

[0298] Carbon scaffold implemented in Li₂S secondary battery

[0299] A group (444B) of plasma spray torches (414B to 420B) can be configured or adjusted to spray carbon-based material in a controlled manner to achieve a specific desired hierarchical and organizational structure, such as an open porous scaffold (102A) of carbon-based particles (100A and / or 100E) having a continuous microstructure (107F) suitable for use in Li ion penetration through internal capillary action, depending on the porosity percentage of the carbon-based particles (100A and / or 100E). The total amount of S that can be injected into adjacent microstructures (107L) and / or deposited on exposed surface areas of carbon-based particles (100A and / or 100E) and other similar structures may also depend on the porosity percentage, where 3D fractal shape structures providing larger pores, such as pores (105L) having dimensions (103L), can efficiently accommodate and finely confine S for a desired time frame during electrochemical cell operation. There are examples in which combinations of S are allowed to prevent polysulfide (PS) generated by designing and growing pure structural S with the goal of confining S to a percentage defined as follows: 0-5%, 0-10%, 0-30%, 0-40%, 0-50%, 0-60%, 0-70%, 0-80%, 0-90%, and / or 0-100%, any one or more of these ranges successfully demonstrate a delay in polysulfide migration out of the electrode structure.

[0300] Carbon scaffold implemented in a Li-air secondary battery

[0301] Existing Li-air cathodes can only last for 3 to 10 cycles and are therefore not yet universally understood as providing a very promising or reliable technology. In these cathodes, air itself acts as the cathode, so a stable and powerful supply of air flowing through the cathode, such as through a pore, orifice, or other opening, effectively excludes practical applications in consumer-grade portable electronic devices such as smartphones.

[0302] The device can be constructed using a type of air pump mechanism, but air purification remains a problem, given that the amount of impurities pervasive in the air can react with available Li in parasitic side reactions and ultimately reduce the capacity of the entire electrochemical cell. Additionally, since air provides only about 20.9% O2, it is not as efficient as other alternative current advanced battery technologies.

[0303] Nevertheless, even in light of the problem mentioned above, the example provided above can be configured to operate in a 3D printed battery with respect to any variation thereof implemented in carbon-based particles (100A, 100E) and / or carbon scaffolds (300B) and / or lithiated carbon scaffolds (400A). In particular, measures can be taken to prevent unwanted and / or sudden collapse of the porous structure, such as creating blockages in defined passages, such as adjusting to achieve desirable structural reinforcement in specific target areas of the open porous scaffold (102A). For example, the carbon scaffold (300B) can be decorated with numerous metal oxides to achieve such reinforcement, and when lithium reacts with air to spontaneously form a solid in that state, it can control or positively contribute to the mechanical tunneling of the structure itself. Traditional situations, such as those without special preparations performed in connection with the implementation of carbon-based particles (100A) initiated using a Li air cathode, may involve Li ions reacting with carbon provided in a gaseous state so that the Li ions and the carbon-containing gas react in a different way to form an expanding solid. And, depending on the location where this expansion occurs, the entire carbon-based mesoporous scaffold structure, such as a carbon scaffold (300B), may be mechanically degraded.

[0304] Lithium-based particle preparation

[0305] In order to enable alternative non-Li or lithiated carbon-based scaffold cathodes, such as those trapping sulfur, oxygen, and vanadium oxides compared to current lithium oxide compound cathodes, as well as to accommodate first-charge lithium loss in current lithium-ion batteries and reduce Coulomb efficiency, a scalable pre-lithiation method of carbon-based structures to be implemented in electrochemical cell electrodes may be required. As a result, various experimental attempts have been made using carbon-based particles (100A, 100E) and / or any derivative structures based thereon, including carbon scaffolds (300B) such as ball milling, annealing after heat treatment, and electrochemical reduction from additional electrodes. These efforts have been used for pre-lithiation, such as chemically preparing carbon-based structures to react with and / or confine lithium physically and / or chemically, but have addressed issues of uniformity, lithium reactivity, cost, and scalability.

[0306] Nevertheless, by fine-tuning the reactor process parameters, carbon-based particles (100A, 100E) and / or carbon scaffolds (300B) can be synthesized and / or manufactured by a layer-by-layer deposition process as previously discussed, having carbon-based host structural dynamics with engineered surface chemistry, such as including nitrogen and oxygen doping to promote rapid decomposition associated with oxide imbalance.

[0307] Upon thermal activation that may involve the formation of one or more sparks, Li metal may infiltrate non-reactively, driven by capillary forces, for example without a pressure gradient, to generate controlled and pre-lithiated carbon structures or particle building blocks. Consequently, these pre-lithiated particle building blocks are:

[0308] As illustrated by the intermediate layer (406A), in high conductivity at the backplane in contact with the current collector,

[0309] It can be synthesized into an integrated composite film having differential electrical conductivity as an insulating ion conductive layer of the electrolyte / electrode plane.

[0310] Surface chemistry associated with the non-reactive penetration of Li metal can be tuned by optimizing the degree of oxide thermal reduction, such as exothermic reactions, using thermogravimetric analysis (TGA) or differential scanning calorimetry (DSC) analysis techniques.

[0311] To address scalability issues that may arise from transitioning from a small-scale laboratory test and sample production environment to a large-capacity plant capable of simultaneously fulfilling multiple customer orders, the pre-lithiation process described above can be easily applied to a continuous roll-to-roll (R2R) format, similar to other liquid melt wetting processes such as brazing.

[0312] A thin film Li-clad foil, which may include tantalum (Ta) or copper (Cu) in some compositions, can be loaded onto a heated calender roll to come into contact with carbon-based particles (100A) or a carbon film for a spray torch process in a controlled thermal drying environment. Thermal retention, such as immersion, time, gradient, and applied pressure, can be adjusted and controlled to facilitate both of the following: (1) activation; and (2) an infiltration process step.

[0313] Initiation of lithiation of carbon scaffolds

[0314] Prior to the development of a method for injecting Li metal into carbon-based structures and / or lump particles, efforts were undertaken to evaluate the following two scenarios:

[0315] Microwave graphene sheet growth with extended D-spacing that allows Li intercalation between individual graphene sheets to occur much more efficiently or at a faster rate than that occurring in typical commercially available graphene sheets; and, growing FLG in such a manner to successfully and repeatedly achieve such higher D-spacing; and

[0316] Use of a wet liquid Li metal front that propagates to an adjacent microstructure (107F) defined by an open porous scaffold (102A) of hierarchical pores (101A) and / or carbon-based particles (100A and / or 100E), where the attraction from the Li metal to the exposed carbon-based surface wets the surface compared to otherwise functionalizing the exposed carbon-based surface.

[0317] The thermal reactor disclosed at present can perform hammering the surface of the particles to promote the penetration of molten (Li) metal front without post-processing and additional pressure from an external source to produce highly organized and structured carbon having functions related to the penetration of molten Li metal and / or other species, such as aluminum penetration into silicon carbide sintered materials. This effort allows for continuous wetting instead of using capillary pressure to push the metal into the open porous scaffold (102A) of the carbonaceous particles (100A and / or 100E).

[0318] FIG. 4a illustrates a lithiated carbon scaffold formed from several interconnected carbon-based particles (402A) similar in form and function to carbon-based particles (100A and / or 100E) synthesized and deposited in film layers (406A to 412A) at various concentration levels, from the most concentrated to the least concentrated. All film layers (406A-412A) are configured to be infiltrated via a non-reactive capillary injection method with a molten Li metal and / or Li ion solution in a liquid state or phase for the insertion of Li ions between pairs of graphene sheets of graphene sheet (101B). An exemplary D-spacing of approximately 1 Å to 3 Å can be targeted during the synthesis of the graphene sheet (101B) to retain more Li ions between alternating graphene sheets than in a conventional graphene sheet stack.

[0319] A void (416A) representing an empty region or space between adjacent and / or contacting carbon-based particles (402A) may be defined by a section of lithiated carbon scaffold (400A) located away from the current collector (420A) and facing the liquid electrolyte layer, passivation layer (418A). Passivation means that the material becomes passive, i.e., less affected by or corroded in the future usage environment. Additionally, or alternatively, a Li ion-conducting insulation, or differential interphase layer may be deposited on the same layer (412A) as the same location of the passivation layer (418A) facing the electrolyte (414A) to minimize side reactions with glass in ionic form and / or physically and / or chemically unattached Li.

[0320] Prior to the deposition or placement of any such periphery layer, Li provided by molten Li metal may flow in a liquid state into the pores (416A) defined by the carbonaceous particles (402A) to help form an electrochemical gradient proportional to the concentration level of the carbonaceous particles (402A) in each layer of the film layer (406A-412A).

[0321] When repetitive or periodic Li-ion electrodes, such as anodes or cathodes, are used in secondary batteries, problems such as volume expansion during redeposition in electroplating operations can occur due to the use of molten Li metal. This refers to a process that uses an electric current to reduce dissolved metal cations and form a thin, cohesive metal coating on the electrode. This term can also be used for the electro-oxidation of anions on a solid substrate, such as forming silver chloride on a silver wire to make a silver / silver chloride electrode.

[0322] The process used for electroplating in relation to the penetration of a Li-ion solution into a lithiated carbon scaffold (400A) can be described as electrodeposition, also known as electrophoretic deposition (EPD), and is similar to a concentration cell acting in reverse. As previously mentioned, electroplating with Li-ions can result in a volume expansion of approximately 400% or more of the lithiated carbon scaffold (400A). Such expansion is undesirable in terms of micromechanical stability and causes performance degradation with many dead zones, referring to inactive or non-chemically and / or electrically active regions, thereby ultimately preventing the induction of a longer lifespan in a lithium-ion battery installed in this way. Generally, it is desirable to have a majority of the Li-ion material plate, which means it is reduced to a smooth and uniform surface to facilitate the uniform deposition of Li-ions. Removal is also smooth at a smooth planar interface.

[0323] In fact, when Li penetrates into the carbon scaffold (400A), it may tend to form unwanted dendrites, which are defined as crystals that develop into a typical multi-branched tree-like form. These Li-ion dendrites, which are in the form of needle-like Li-ion dendrites describing a crystal habit consisting of slender needle-shaped crystal precipitates, are located away from the surface where Li-ions penetrate, such as on and / or between individual graphene sheets (101B). Under certain circumstances, with sufficient battery charge-discharge cycling, dendrite protrusions or projections can grow all the way from the anode containing the lithiated carbon-based scaffold (400A) to the cathode located opposite the carbon-based scaffold within the electrochemical cell, causing a short path or circuit that describes a case where there is a low-resistance connection between the two conductors supplying power to the circuit. This can generate excessive voltage streaming and cause excessive current flow to the power source. Electricity flows through the short path and a short circuit occurs.

[0324] Capillary Li-ion implantation technology into a lithiated carbon scaffold (400A) can solve many of the problems described. Nevertheless, a persistent problem faced in lithium-ion batteries is that conventional cathodes provide only a limited amount of specific capacity or energy capacity. Likewise, a decrease in specific capacity and energy density has been observed on the anode side as well. Therefore, even in terms of electrical energy storage capacity and current delivery, Li-ion batteries can be compared to Li metal hydride or lead-acid or Ni-cad batteries, and incorporating one or more of the currently disclosed carbon-based materials, such as a lithiated carbon-based scaffold (400A), to approach the theoretical capacity of pure Li metal, which has a specific capacity of about 3,800 mAh / g, enables much greater advancements in power storage and delivery with regard to protection or prevention of unwanted Li-based dendrite formation.

[0325] Other approaches have been pursued, including the development of solid-state batteries that are entirely free of a liquid phase. However, interest in Li metal has resurfaced due to the oxide electrolytes used to achieve contact and stabilization with Li. Additionally, alternatives to Li metal, including Si, Sn, and various other alloys, have been explored. Nevertheless, even if Li metal is eliminated, a Li ion source may still be required.

[0326] Alternative lithium materials for lithium-ion battery electrode structures can produce the following energy density values: oxides provide 260 mAh / g; and sulfur (S) provides 650 mAh / g. Due to their relatively high energy density capabilities, it is desirable to confine sulfur (S) in battery electrode applications so that it is not solubilized or dissolved in the surrounding electrolyte. To achieve this effect, sulfur micro-confinement is required in relation to the pores (105F) of the adjacent microstructure (107F) of the open porous scaffold (102A) as previously described, as shown in FIG. 1f. A confined (or micro-confined) liquid refers to a liquid to which nano-sized geometric constraints are applied so that most molecules are close enough to the interface to detect slight differences from standard bulk conditions. Typical examples are liquids in porous media or liquids in solvated shells.

[0327] Confinement and / or micro-confinement, referring to confinement within a microscopic size region, regularly prevents crystallization, allowing the liquid to be supercooled below a uniform nucleation temperature, even if this is not possible in the bulk state. Therefore, considering the various problems presented above and other problems not discussed here, various improvements to existing graphite-based anodes can be achieved by instead using few-layer graphene (FLG) materials and / or structures defined as having fewer than 15 graphene layers grown, deposited, or organized in a stacked structure with Li ions intercalated between defined spacing and / or concentration levels. Any one or more of carbon-based particles (100A, 100E), etc., may be prepared in this way.

[0328] By doing so, the transition from graphite to FLG can improve the capacity for Li-intercalated carbon-based structures from approximately 380 to over 1,000 mAh / g. The disclosed material can increase the spacing between individual graphene layers to allow for up to 2 to 3 Li ion penetrations, unlike the 1 Li ion typically seen elsewhere, as shown in Fig. 1i, which indicates that by replacing graphite with FLG, a higher active surface area can be allowed and various graphite or graphene layer planes can be controlled in terms of D-spacing to achieve various Li ion fittings between adjacent graphite or graphene layer planes.

[0329] In graphene, the hexagonal carbon structures of each graphene sheet can be positioned on top of each other, which is referred to as an AA packing sequence instead of an AB packing sequence. An example of a carbon packing sequence is shown in the chemical structure diagram illustrated in Fig. 1h, where Li ions can enter empty spaces defined by carbon atoms arranged and bonded in a hexagonal lattice structure. In particular, a configuration for graphene sheets and / or few-layer graphene (FLG) is envisioned, where individual layers of graphene can be stacked directly on top of each other to obtain an uneven and irregular stacking that does not fit together, as shown in Stage 3 of Fig. 1i, which allows for the intercalation of additional Li ions between each layer of graphene in the FLG structure.

[0330] Under traditional conditions and circumstances, the intercalation of Li ions from the top or bottom in layered graphene structures can actually prove very difficult. In contrast, Li ions are more easily inserted between individual graphene layers separated by a definable distance. Therefore, the key is to precisely manage and adjust the available edge regions. In this regard, any carbon-based structure disclosed herein is adjustable. And, the carbon in graphene is also conductive—therefore, this feature serves a dual role by: (1) providing structural definition to FLG scaffold electrode structures such as carbon scaffolds (300B) and / or lithiated carbon scaffolds (400A) and (2) providing conductive pathways therein.

[0331] The production technology used to manufacture any one or more of the carbon-based structures disclosed herein may indicate that adjustment of the edge lengths of individual graphene layers relative to a planar surface is desirable; additionally, adjustment of the spacing between individual graphene stacks may be possible. Due to its two-dimensional structure, graphene provides a much larger surface area into which lithium ions can be inserted. Accordingly, the application of graphene sheets according to various aspects of the subject matter disclosed herein can provide a natural evolution toward enhanced energy storage density.

[0332] Individual graphene sheets are held in place as part of a plasma growth process. Carbon-based gumball-like structures are self-assembled in flight in FLG and / or combinations thereof as previously described to form carbon-based particles (100A, 100E, 402A), and defined long-range orders are defined as where 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, so that smaller structures aggregate to form something essentially resembling a gumball.

[0333] The size dimensions of the gumball-like structures describing individual carbon-based particles (100A), etc., may be 100 nm across their widest points. As shown in FIG. 18, larger aggregated particles forming a carbon lattice structure (1800) may be composed of multiple gumball-like structures with a diameter of about 20 to 30 microns, or much larger, and may provide structural definition to one or more film layers (406A-412A) shown in FIG. 4a.

[0334] In contrast, traditional battery electrode manufacturing methods typically use known deposition techniques, such as chemical vapor deposition (CVD) or other manufacturing techniques, nanotubes, etc., to grow structures from a defined fixed substrate or surface, and thus do not involve the in-flight fusing of carbon-based particles in a substantially atmospheric pressure vapor stream of carbon-containing gaseous species as disclosed herein. Such known assembly processes and procedures can tend to be very labor-intensive and may also allow for the growth of structures of limited thickness, with a thickness of 200 to 300 microns.

[0335] The densification of graphene-on-graphene of multiple FLGs on original gumball-based carbon scaffolds, such as carbon-based particles (100A), carbon scaffolds (300B), and lithiated carbon scaffolds (400A), can also result in increased energy density and capacity. In the target area of ​​the carbon scaffold, such densification can be performed after the creation of larger aggregated particles containing multiple carbon-based particles (100A) or otherwise achieved. Generally, since Li ions can be plated onto the electrode before reduction, the Li ions can transition from an ionic to a metallic state depending on the battery chemistry. Furthermore, in an implementation, similar to electroplating, graphene can be grown in a stacked manner on other materials such as plastic and tuned to obtain a desired bright and / or smooth finish. This electroplating process is reversible and may include separate but interconnected plating and stripping processes intended to lay Li ions and / or atoms underneath and subsequently remove them.

[0336] In the continuous cyclic use of secondary lithium-ion batteries, including multiple charge-discharge-recharge cycles, the surface on which carbon-based structures are grown and / or built eventually becomes rough and thus susceptible to or accepting unwanted dendrite growth. In contrast, as discussed above, the technology used to produce carbon-based particles (100A) and / or similar ones can substantially prevent the growth of such dendrites by using substantially impurity-free Li metal together with carbon-based graphene structures to enable high capacity values.

[0337] The use of graphene sheets allows for a relatively larger exposed surface area available for intercalation or plating operations for penetration, referring to the non-reactive capillary injection of Li ions. Consequently, the tendency to migrate to specific points is eliminated; furthermore, because graphene has a higher surface-to-volume ratio than conventional carbon-based materials such as graphite, it can fundamentally alter the way plating and delamination occur. Li ions can be introduced by relying at least partially on liquid Li; however, given Li's propensity for chemical reactivity with the surroundings and / or elements, aqueous moisture and oxygen must be avoided. Similarly, the introduction of impurities leads to harmful effects. Metal-matrix composites have been studied regarding the use of metallic bonding of Li in relation to the disclosed carbon-based structures or the formation of metal-matrix composites with C, thus providing additional options for managing and fine-tuning the reactivity of the exposed surface.

[0338] Li in contact with C may result in a situation where the free energy of Li carbides at the contact surface must be suppressed and / or controlled to avoid unwanted reactivity associated with spontaneous Li infiltration in carbonaceous particles (100A), etc. Traditionally, Li generally forms carbonates and other formations due to the chemical properties of the electrolyte in the liquid phase. However, what is proposed by the present embodiment is the formation of a relatively stable solid electrolyte interface (SEI) prior to the introduction of the liquid electrolyte.

[0339] Furthermore, a number of methods and / or processes that affect the Li ion interface region may be available. For example, alloying the surface of liquid Li with Si and other elements will reduce reactivity and promote the overall Li ion wetting of larger aggregated particles, each containing multiple carbon-based particles (100A). In the example, it was observed that approximately less than 1.5% of Li preferentially migrated to the exposed surface exposed to the electrolyte.

[0340] 3D hierarchical graphene with increased capacity (~3x) compared to conventional graphite anodes

[0341] The commercial use of graphite carbon materials for anode active materials and fine carbon black materials for electrical conduction is justified by their relatively low cost, excellent structural integrity for the insertion and extraction of Li+ ions, safety without Li dendrite formation, and the formation of a protective passivation layer for many electrolytes, such as those associated with the formation or accumulation of solid electrolyte interface phases (SEI).

[0342] However, the low specific capacity of graphite with a stoichiometric formula (LiC6) of 372 mAh / g is a significant limitation and, consequently, may potentially hinder the development of large-scale energy storage systems requiring high energy and power densities. By designing and applying three-dimensional (3D) graphene having an intercalated Li and / or S compound electrode approach disclosed herein by any one or more of the aforementioned drawings, a larger loading of the active anode material can be accommodated while promoting Li ion diffusion. Additionally, a 3D nanocarbon framework, such as that defined by an open porous scaffold (102A), etc., can impart the following:

[0343] Electrical conduction path; and

[0344] Structural buffers for high-capacity non-carbon nanomaterials result in enhanced lithium-ion storage capacity.

[0345] Both (1) and (2) can improve lithium-ion storage capacity (> 1,000 mAh / g) and improved cycling (stability) performance can be achieved with these 3D structures.

[0346] Integrated with Li-ion (and Li-S) battery electrodes

[0347] An exemplary Li-ion or Li-S, secondary electrochemical cell system (500) in which an anode (501) and a cathode (502) are separated by a separator (517) is illustrated in FIG. 5. Any one or more of the anode (501) and the cathode (502) are substantially formed by a lithiated carbon scaffold (400A) illustrated in FIG. 4a, which is represented by a simplified representation of larger and smaller carbon particles (509), all of which at least partially define a Li-ion conductive electrolyte solution (518) containing a dissociated Li-ion conductive salt (505) as illustrated. A separator, which is a porous membrane that electrically insulates the anode (501) and the cathode (502), is also located in the illustrated position. A single Li ion migrates back and forth through the path (507) between the electrodes of the Li-ion battery during the discharge-charge cycle and is intercalated into a carbon-based active material forming either one or more of the anode (501) and cathode (502) to be confined inside as needed for optimal secondary electrochemical cell (500) performance.

[0348] Electrolytes, such as the electrolyte solution (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 batteries due to their high ionic conductivity, low surface tension, low interfacial impedance, and excellent wettability within the electrode. In Li₂S battery systems, liquid electrolytes are dominant because they help compensate for the potentially poor electrochemical kinetics of S and lithium sulfide (Li₂S). In Li₂S systems, liquid electrolytes containing ether-based solvents can be used because ether-based solvents do not react negatively with S unlike carbonates and generally have better Li ion transport properties. A potential disadvantage of using ether-based electrolytes is the solubility of long-chain polysulfides (PS), which can lead to the decomposition of the Li₂S electrochemical cell due to volume expansion of the cathode, which eventually leads to PS shuttles, migration, and damage to structural integrity.

[0349] In addition to conventional liquid electrolytes, solid-state electrolytes can be configured to potentially stop the formation and growth of Li dendrites and to stop PS shuttles because the solid-state electrolyte effectively converts the Li₂S system from a multiphase system to a single phase system, resulting in no internal short circuits, no electrolyte leakage, and no flammability. Solid polymer electrolytes can be defined as porous membranes capable of transporting Li ions across the corresponding membrane. Solid electrolytes can be further classified into solid polymer electrolytes, gel polymer electrolytes, and non-polymer electrolytes. Solid polymer electrolytes can consist of lithium salts dissolved in a high molecular weight polymer host. Common polymer hosts used include polyethylene glycol (PEO), polyvinylidene fluoride or polyvinylidene difluoride (PVDF), poly(p-phenylene oxide) or poly(PPO), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), and poly(methyl methacrylate) (PMMA).

[0350] Gel polymer electrolytes can be similar to solid polymer electrolytes in that they contain high molecular weight polymers but include a liquid component tightly trapped within the polymer matrix. In some implementations, gel polymer electrolytes have been developed to compensate for the poor ionic conductivity observed in solid polymer electrolytes. Compared to other forms of solid electrolytes, non-polymer solid electrolytes have the advantage of high thermal and chemical stability.

[0351] Non-polymer solid electrolytes are composed of ceramics, and commonly found non-polymer electrolytes include lithium superion conductors (LISICON) and Li7La3Zr20. 12 (LLZO), Li7La 2.75 Ca 0.25 Zr 1.75 Nb 0.25 O 12 (LLCZN), garnet, and Ge-doped Li 0.33 La 0.56It may include TiO3 (Ge-LLTO) perovskite, etc., and may have a thickness in the range of approximately 0.5 µm to 40 µm, which can be configured to substantially prevent the formation or growth of one or more Li dendrites. Nevertheless, some solid electrolytes may suffer from certain problems, including relatively poor Li ion conductivity and weight. At the thickness required to prevent Li dendrite growth, the observed ion impedance may be too high so that the mounted Li ion or Li S battery may not function as desired, whereas at the thickness required to have acceptable Li ion conductivity, Li dendrite growth may not be prevented.

[0352] During discharge, Li is deintercalated from the anode (501). The active material of the cathode (502) may include a mixed oxide. The active material of the anode (501) may include amorphous carbon compounds, mainly graphite and those presented herein. This is the material to which Li is intercalated.

[0353] The Li ion conductive salt (505) can be dissociated to provide mobile Li ions available for intercalation to any one or more of the unique carbon-based structures disclosed herein that can be incorporated as a forming material to achieve a specific capacity holding capability exceeding 1,100 mAh / g as facilitated by a continuous microstructure (107F). The Li ions are temporarily restricted during charge-discharge cycles to a level that cannot otherwise be achieved through conventional unorganized carbon structures, which require bonding via adhesive definitions and binders, which may impair overall battery performance and lifespan as previously discussed.

[0354] Pores (105F) of the adjacent microstructure (107F) shown in FIG. 1f, which can be used to create a conductive graded film layer for any one or more of the anode (501) or cathode (502) and form carbon-based particles (100A, 100E, 402A) and / or similar, can be defined to contain a micropore volume (pores < 1.5 nm) during synthesis. Sulfur (S) is injected into the S-trapped pores (105F) via capillary forces. Successfully trapping sulfur microscopically generally prevents dissolved polysulfide (PS) from redepositing outside the original pores, as previously presented in relation to Li₂S systems. To achieve an activated carbon composite capable of holding an achievable amount of S, a pore volume of 1.7 cc / g with a total of 1.7 cc / g attributed to pores having an opening of <1.5 nm may be required.

[0355] Operatory, in a Li ion or Li S system, Li ions migrate from the anode (501) to the cathode (502) through the electrolyte (518) and the separator (517). Here, molten Li metal (514) is finely confined within a few-layer graphene sheet (515) associated with any of the currently disclosed carbon-based structures used as a forming material for the anode (501) or cathode (502), as shown in the enlarged areas (516 and 513). The molten Li metal can be dissociated from the anode (501) according to the following equation (8):

[0356] (8)

[0357] Equation (1) illustrates discharging electrons (506 and 511) to power an external load so that Li ions (512) migrating to the cathode (502) return to a thermodynamically preferred position within the cobalt oxide-based lattice according to the following equation (9):

[0358] (9)

[0359] During charging, this process of return-migration of lithium ions (505) from the cathode (502) to the anode (501) through the electrolyte (518) and separator (517) is reversed.

[0360] A carbon-based structure is disclosed that mentions a remarkably favorable specific capacity value made possible by a unique multimodal hierarchical structure of carbon-based particles (100A, 100E) and / or carbon scaffolds (300B) and derivatives thereof, including lithiated carbon scaffolds (400A), any one or more of which may be constructed based on the existing advantages provided by lithium-ion technology. Li ions, which are relatively small compared to sodium or potassium ions, exhibit much faster dynamics in various oxide cathode materials. Another difference is that, unlike other alkali metals, Li ions can reversibly intercalate and deintercalate in graphite and silicon (Si). And lithiated graphite electrodes enable higher cell voltages. The carbon-based material disclosed, which is suitable for hard case, pouch cell, and prism applications and has a unique layout of few-layer graphene (FLG) such as 5-15 graphene layers in a generally horizontally stacked configuration (101C) as used in carbon-based particles (100A), improves the ease with which Li ions can be reversibly intercalated and deintercalated between the graphene sheets.

[0361] Stabilization of artificial solid electrolyte interface (SEI) films by doping

[0362] Currently, current Li-ion batteries form a protective passivation layer (e.g., the passivation layer (418A) shown in FIG. 4a) or a solid electrolyte interface (SEI) on the electrode surface exposed to the electrolyte during a pre-conditioning phase followed by an initial discharge and charge phase after the electrolyte is first introduced. Electrolyte chemistry and pre-conditioning protocols, such as charge / discharge rates and overvoltage, can be adjusted to optimize film passivation by reference to SEI formation, but the existing film layer integrated into the electrode may still be chemically and mechanically unstable.

[0363] Now, referring to FIG. 6a, a specific element (602A) can be introduced into the aforementioned carbon material (600A) by doping. On an exemplary exposed electrode surface (601A), elements (602A), such as silicon, sulfur, nitrogen, and phosphorus, can be coated on the electrode surface (601A) of the carbon structure to a specific level of conformal coverage, ranging from a coarse decoration to complete conformal coverage. Priorities for the formation of a stable solid-state electrolyte ion-conducting layer have been reported in the literature; chemical formula Li 3.25 Ge 0.25 P 0.75 Sulfide-based thioLISCON, defined as a lithium sulfur conductor having S4, and generally the chemical formula Na i+x Zr2Si x P 3-x O 12, 0 < x < 3 refers to phosphate-based NASCIONs such as sodium (Na) superionic conductors, which generally represent a solid series, and the abbreviation is also used for similar compounds where Na, Zr and / or Si are replaced with equivalent elements. The formation of the stabilized solid-state passivation layer described herein involves doping with a specific element (602A), and the electrode surface (601A) can be designed prior to battery assembly, thereby isolating the process of forming a stable solid-state ionic conductive layer from reduction / oxidation events that occur when in contact with the electrolyte, which are still difficult to achieve stable operation over a long period in current lithium-ion battery manufacturing.

[0364] Manufacturing using slurry casting technology

[0365] Any one or more of the modified 3D hierarchical graphene-based particles disclosed herein in combination with conductive particles such as carbon black, and optionally a polymer binder such as NMP and a solvent, may be directly incorporated into a conventional slurry-cast electrode manufacturing process as follows:

[0366] For the anode, an active graphene-based (FLG) replacing graphite particles; and / or

[0367] In the case of the cathode, active sulfur (S) injection.

[0368] The 3D graphene particles provide high-capacity graphene building blocks with interconnected mesoporous ion conduction channels for rapid Li-ion transport, together with carbon black and a binder, to ensure electrical conduction pathways such as those defined by the graphene sheet (101B) used as a forming material for a continuous microstructure (107F) that also provides mechanical integrity.

[0369] The disclosed carbon material can be pre-lithiated by ball milling and / or post-thermal annealing and electrochemical reduction of a third electrode at the following locations:

[0370] A relatively low concentration to offset the first charge Li loss in conventional oxide cathode cells; or

[0371] Increasing the total specific capacity for both oxide and alternative cathode configurations at relatively higher concentrations, and then casting the slurry to the electrode.

[0372] FIGS. 6b1 and 6b2 illustrate schematic diagrams comparing a chemically non-reactive system (600B1) versus a chemically reactive system (600B2) with respect to active material infiltration and lithium (Li) confinement within the active material according to some implementations. While the configuration involves molten Li metal infiltrating any one or more of the currently disclosed carbon-based structures illustrated in FIGS. 1a through 1f, such as an adjacent microstructure (107F), alternative or additional implementations provide the injection of molten Li metal droplets in a vapor phase into pores, such as pores (105F). In the chemically non-reactive system (600B1), it is expected that the Li metal droplets will not react with the carbon when prepared or when in contact with the exposed carbon surface, for example, due to the Li-phobicity of the carbon. Nevertheless, the injection of vapor-phase Li droplets at an intrinsic contact angle (θ) between about 50° and 90° results in a liquid-phase molten Li droplet and a liquid ( )of ( It can provide a balance between competing liquid-solid adhesive forces, such as the adhesion observed between solid carbons that is proportional to the cohesive force.

[0373] Wetting occurring between vapor-phase Li and solid-phase carbon is defined as the ability of a liquid to maintain contact with a solid surface, and the degree or wettability arises from intermolecular interactions when the two come together, which can be determined by the balance of forces between adhesion and cohesion. Desired degree of wetting can occur when the adhesion energy is close to the cohesion energy, such as in semiconductors including silicon (Si), germanium (Ge), or silicon carbide (SiC), as well as ceramics containing one or more of carbides, nitrides, or borides that may exhibit metal-like behavior near exposed surfaces, or in liquid-phase metals dispersed in solid-phase metals, where the adhesion energy is close to the cohesion energy. Furthermore, using a liquid-phase metal that is relatively soluble to atmospheric contaminants such as oxygen (O), nitrogen (N), moisture (H2O vapor), or carbon can reduce the contact angle required or be observed during wetting on contaminated solid surfaces or pure carbon surfaces.

[0374] In a chemically reactive system (600B2), the wetting of a carbon surface layer (602B2), such as that encountered on the surface of a carbon-based particle (100A) exposed to Li metal, may be accompanied by chemical reactions occurring at the interface, such as the dissolution of solid carbon material or the formation of a compound involving at least partial consumption of a new 3D layer (604B2) or the underlying carbon surface layer (604B2). The addition of a dopant adjusted according to type and concentration in the carbon surface layer (602B2), as shown by various fluid positions (606B2, 608B2, 610B2), illustrating molten Li droplets having very little wetting at position (606B2) with progressively greater wetting at positions (608B2 and 610B2), respectively, may affect the degree or extent of wetting. The formation of the new 3D layer (604B2) may, in some embodiments, alter properties of the underlying carbon surface layer (602B2), such as electrical conductivity, and may limit penetration into the porous medium by pinching off the formation of the volume expansion reaction product, which is depicted as the new 3D layer (604B2).

[0375] For a chemically non-reactive system (600B1) or a chemically reactive system (600B2), reducing the contact angle of the liquid Li metal droplet beads as shown in position (610B2) can promote the wetting of the underlying carbon surface layer (602B2). And in the case where the carbon surface layer (602B2) is composed of adsorbed or chemically bonded oxygen (O), adding an element, also known as a getter, having high O solubility can reduce or otherwise control O activity in the new 3D layer (604B2). In the case of a solid deformation of the carbon surface layer (602B2), adding elements such as nickel (Ni), iron (Fe), etc., to the liquid metal having high carbon solubility can ensure relatively high surface activity or affinity.

[0376] FIG. 7 illustrates an exemplary process workflow in which, depending on some implementation, molten Li metal penetrates into the voids between carbon aggregates and initiates a reaction on the exposed carbon surface. Considerations for infiltrating a packed carbon scaffold (702) with Li metal (704, 706) that can provide a forming material for any one or more of the currently disclosed carbon-based structures, such as the carbon particles (100A) shown in FIG. 1a or the adjacent microstructure (107F) shown in FIG. 1f, or be incorporated therein, are illustrated in the infiltration process workflow schematic (700). The surface conditions of the carbon scaffold (702) can be adjusted prior to infiltration by molten Li metal, which may be introduced into the carbon scaffold (702) by one or more of capillary injection using liquid molten Li metal or injection of molten Li metal droplets suspended in air to form Li metal vapor. The precise adjustment of the following conditions on the surface of the carbon scaffold (702) exposed to the incoming Li includes:

[0377] Atmospheric pollutants such as moisture (H2O vapor), oxygen (O), nitrogen (N), and hydrocarbons configured to trap or contain O via physical adsorption or chemical adsorption;

[0378] Formation of nitrogen bonds on the surface after plasma treatment; and

[0379] Purity of lithium metal, such as control of common surface oxides, nitrides, and carbonates.

[0380] Li infiltration can be initiated by capillary injection of molten Li metal (704, 706) to form a lithiated carbon compound (708) that is not only intermingled within the carbon scaffold (702) but also filled into the empty space of the packed carbon scaffold (702). The procedure may be followed by non-reactive Li wetting infiltration and post-reaction treatment. Various specific process options exist for Li to infiltrate into the carbon scaffold (702), including the following:

[0381] The use of molten Li metal to initiate a reaction on an exposed carbon surface—assuming controlled hydroxyl (OH) and oxygen (O) adsorption conditions on the exposed surface of a carbon scaffold (702), such as one or more lipophilic functionalized surfaces configured to expose the carbon scaffold (702) to Li adsorption centers, thermal oxide reduction, or pristine molten Li metal vapor located on top of the carbon scaffold (702) for a duration of about 30 to 45 seconds at about 200 °C—can initiate a chemical reaction on the exposed surface of the carbon scaffold (702) to form a lithium-affinity surface such as LiC6;

[0382] To control surface contaminants in the interface region between molten Li metal and exposed carbon, the exposed carbon surface is coated with a surface-active element—fluxing elements can be used to destroy oxide skulls or promote the melting of halogens including fluorine (F), and oxide getters can be used to reduce oxides (Ti, etc.);

[0383] The exposed carbon surface is coated with an element such as a metal having a surface energy lower than Li and / or an element such as silicon (Si) or aluminum (Al) that promotes Li wetting and / or penetration to promote alloying and wetting; and

[0384] Metal-containing compounds, such as metal powder or silicon carbide (SiC), can be incorporated into carbon preforms such as SiNPs or Ni to act as binders and promote wetting penetration, thereby allowing the ratio of metal to carbon to be controlled according to non-reactive wetting parameters. Figure 8a illustrates an equation for the penetration rate of a carbon-based structure having an internal space defined by any one or more of the 3D carbon-based particles shown in Figures 1a to 1f, depending on some implementation.

[0385] FIG. 8a illustrates an equation for modeling the Li penetration rate into any one or more of the porous regions of the currently presented carbon-based structure, such as the pores (105F) and adjacent paths (107) shown in FIG. 1f of the carbon-based particle (100A) shown in FIG. 1a. The penetration rate can be controlled by the non-reactive viscous resistance of a liquid metal, such as molten Li metal, and subsequently by the chemical reaction between the liquid metal in contact with the carbon to produce a carbide according to the Washburn equation 800A shown in FIG. 8a, where σ and η are the surface tension and viscosity of the liquid, respectively, θ is the contact angle, and r eff is the effective pore radius of a pore (105F) shown in Fig. 1f that can be scattered throughout a carbon-based scaffold, such as the carbon-based scaffold 702 shown in Fig. 7. Thus, as can be seen from the various coefficients used in Washburn's equation (800A), capillary flow is explained by effectively expressing absorption into a porous material by modeling the carbon-based preform structure as a theoretical bundle of parallel cylindrical tubes.

[0386] FIG. 8b illustrates a non-reactive system (800B) comprising a non-wetting configuration (802B) and a spontaneously wetting configuration (804B) according to some implementations. For example:

[0387] In a non-wetting configuration (802B), to overcome capillary pressure, pressure (P o) is applied, and, for example, the pressure between two immiscible fluids in a thin tube may be limited by viscous friction, such as that which arises from the interaction of forces between the fluid and the rigid wall of the tube and is set and characterized by Washburn's equation (800A); L may represent a liquid Li layer, such as 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, which is characterized by Washburn's equation (800A) in the contact region between L and S;

[0388] In the spontaneous wetting configuration (804B), θ is maintained at an angle < 60° to achieve non-reactive Li penetration into the carbon-based scaffold; and

[0389] Any one or more of the non-wetting configuration (802B) or the spontaneously wetting configuration (804B) may be incorporated into or otherwise implemented in the exemplary carbon-based scaffold (806B), which may be a forming part of any one or more of the carbon-based structures currently disclosed.

[0390] FIG. 8c illustrates a reactive system (800C) comprising a wettable reactive product layer configuration (802C) and a non-wettable surface layer configuration (804B) according to some implementations. The wettable reactive product layer configuration (802C) may include the formation of a new 3D layer (806C) similar to that previously discussed in relation to the chemical reactive system (600B2) illustrated in FIG. 6b2, wherein the formation of the new 3D layer (604B2) or compound involves the consumption of at least partially underlying carbon surface layer (604B2). Here, the solid carbon material (S) may be LiC6 or may be at least partially consumed to produce or create a new 3D layer (806C) that may contain it. In contrast, in a non-wetting surface layer configuration (804B), the surface immediately facing S, such as in the vertical direction, is non-reactive, so the encroachment of L into the capillary, tubular, open region causes a wasteful reaction with S to create a new 3D layer (808C) along the capillary open region.

[0391] FIG. 9 illustrates a flowchart (900) for a method of lithiating and alloying a carbon-based structure according to some implementations. In block (902), oxide pyrolysis may be used to initiate a surface interface reaction by lithium (Li) vapor pressure to activate the surface of carbon in a packed preform. In block (904), in the example of Li film penetration into a metal substrate, a surface-active element compound may be evaporated to decompose the oxide flux and / or promote wetting. In block (906), alloying elements such as silicon (Si), aluminum (Al), and potassium (K) may be incorporated as part of the penetration process to promote penetration at the interface and / or manage oxygen activity.

[0392] FIG. 10a illustrates a flowchart for a method (1000A) for preparing a carbon-based structure to undergo lithiation, according to some implementations. In block (1002A), a procedure for testing a lithium foil / powder preform can be established. In block (1004A), a proxy metal powder preform can be used to facilitate non-reactive infiltration while understanding a reproducible protocol for lithium management, such as surface pretreatment / impurity management. In block (1006A), the carbon surface activation / pretreatment protocol can be evaluated by measuring the thermal activation response through various techniques including thermogravimetric analysis (TGA) and / or differential scanning calorimetry (DSC).

[0393] FIG. 10b illustrates a flowchart for another method (1000B) for preparing a Li material suitable for use in a lithiation operation according to some embodiments. In block (1002B), a heater platen may be calibrated and thermal profiling of the material may be performed. In block (1004B), a glove box environment including conditions or settings for moisture and oxygen before, during, and after testing may be determined. In block (1006B), the sample may be prepared in any one or more of a lithium foil, lithium evaporated on a metal foil, and carbon powder.

[0394] FIG. 10c shows a flowchart for a method (1000C) for nucleating a plurality of carbon particles at a first concentration level. In block (1002C), a plurality of carbon particles may be nucleated at a first concentration level configured to form a first film on a sacrificial substrate, and each carbon particle comprises a plurality of aggregates comprising a plurality of few-layer graphene sheets fused together. In block (1004C), a porous structure may be formed based on a plurality of few-layer graphene sheets fused together. In block (1006C), molten Li metal may be injected into the porous structure.

[0395] FIG. 10d illustrates a flowchart for a method (1000D) for nucleating a plurality of carbon particles at a second concentration level. In block (1002D), carbon particles can be nucleated at a second concentration level on a first film. In block (1004D), a second film can be formed based on the second concentration level of the carbon particles.

[0396] FIG. 10e illustrates a flowchart for a method (1000E) for growing carbon particles. In block (1002), carbon particles can be grown on a roll-to-roll processing device.

[0397] FIG. 10f illustrates a flowchart for a method (1000F) for evaporating molten Li metal. In block (1002E), molten Li metal can be evaporated onto a metal foil. In block (1004E), molten Li metal can be rolled from the metal foil into a porous structure.

[0398] FIG. 10g illustrates a flowchart for a method (1000G) for preparing an anode to participate in the reversible transfer of Li ions. In block (1002G), the anode may be prepared to participate in the reversible transfer of Li ions with the cathode. The cathode is prepared by one or more of chemical functionalization or sulfidation.

[0399] FIG. 10h illustrates a flowchart for a method (1000H) for densifying a plurality of graphene sheets. In block (1002H), a plurality of graphene sheets can be densified on a porous structure.

[0400] FIG. 10i illustrates a flowchart for a method (1000I) of depositing a first plurality of carbon particles to form a first film. In block (1002I), a first plurality of carbon particles may be deposited to form a first film configured to provide first electrical conductivity on a substrate. In block (1004I), a plurality of 3D assemblies formed of a few-layer graphene sheets may be orthogonally fused together to define a porous structure. In block (1006I), a porous array may be formed in the porous structure. In block (1008I), molten Li metal may be injected into the porous structure.

[0401] FIG. 10j illustrates a flowchart for a method (1000J) for depositing a second plurality of carbon particles. In block (1002J), a second plurality of carbon particles may be deposited on a first film. In block (1004J), a second film may be formed based on the second plurality of carbon particles.

[0402] FIG. 10k illustrates a flowchart for a method (1000K) of infiltrating molten Li metal. In block (1002K), molten Li metal can be infiltrated into the pore structure in a vapor phase. In 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 pore structure. In block (1006K), one or more lithium-affinity surfaces can be formed from one or more exposed surfaces.

[0403] FIG. 10L illustrates a flowchart for a method (1000L) of coating any one or more of lithium-affinity surfaces. In block (1002L), any one or more of the lithium-affinity surfaces may be coated with an active element comprising any one or more of an oxide getter containing titanium (Ti) and a halogen.

[0404] FIG. 10m illustrates a flowchart for a method (1000M) of coating any one or more of lithium-affinity surfaces. In block (1002M), any one or more of the lithium-affinity surfaces may be coated with any one or more elements having a surface energy lower than Li, including silicon (Si) or aluminum (Al). In block (1004M), the wetting enhancement of any one or more of the lithium-affinity surfaces having any one or more elements having a surface energy lower than Li may be promoted.

[0405] FIG. 10n illustrates a flowchart for a method (1000N) for producing a binder. In block (1002N), a binder may be produced by incorporating any one or more of a metal-containing compound or metal powder containing silicon carbide (SiC) into a carbon scaffold.

[0406] FIG. 100 illustrates a flowchart for a method (10000) of adding a certain amount of dopant. In block (10020), a certain amount of dopant may be present at the interface. In block (10040), the degree of Li wetting may be affected in correspondence with the amount of dopant.

[0407] FIG. 10p shows a flowchart for a method (1000P) for controlling the adsorption of hydroxyl (OH) or hydroxyl (OH) groups. In block (1002P), the adsorption of hydroxyl (OH) or hydroxyl (OH) groups can be controlled on any one of the exposed surfaces of the pore structure.

[0408] FIG. 11a illustrates a flowchart for a lithium injection method (1100A). In block (1102A), lithium can be injected using roll-to-roll furnace brazing or spontaneous infiltration. In block (1104A), a two-dimensional (2D) analog can be used with a 2D liquid gap filler. In block (1106A), the injected lithium metal can chemically react at the liquid-to-solid interface with an exposed carbon surface having a controlled flux for activation, increased and / or decreased surface tension, and controlled thermodynamic driving force. In block (1108A), rapid screening of lithium wettability can be performed with Li foil / carbon particles stacked on a hot plate by using a halogen intermediate layer to decompose Li2O.

[0409] FIG. 11b illustrates a flowchart for a method (1100B) of evaporating lithium (Li) onto a metal foil. In block (1102B), lithium can be evaporated onto a metal foil that can act as a thermal conductor. In block (1104B), copper can optionally be used as a current collector and / or tantalum for emission to achieve minimal chemical interaction. In block (1106B), the film thickness can be tuned in proportion to the pore volume of the packed carbon-based particles and / or structure.

[0410] FIG. 11c illustrates another flowchart for a method (1100C) for preparing carbon particles for lithiation through a process referred to, for example, as pre-lithiation. In block (1102C), the pre-lithiated and / or pre-formed foil on the carbon particle packing bed can be oriented with an applied load, such as a calender roll type, under drying chamber environmental conditions. In block (1104C), overall isothermal-like conditions, such as approximately 180°C and / or just below the Li melting point, can be created across the packed particles and Li, with rapid thermal spikes at the concentrated loading location. In block (1106C), a capillary-driven fluid flow can be used in a porous carbon medium utilizing principles related to Darcy's law, washburn, etc., which have variable permeability after initiating penetration using an exothermic reaction. The capillary-driven fluid flow does not assume the formation / accumulation of detectable reaction products.

[0411] FIG. 12 illustrates a flowchart of a method (1200) for performing Li injection of carbon particles while carbon particles are formed with vaporized Li according to some implementation. In block (1202), a metal such as copper and / or tantalum, foil, may be coated with lithium as in a vacuum evaporator; and a measured Li volume, such as thickness and density, may correspond to the pore volume of the packed particle layer. In block (1204), the particles may be assembled into a packed film without a binder through the creation of a granular material, such as a film, from fine particles and size expansion, and assembly techniques may include tumbling, pressure compression, thermal reaction, fusion, drying, aggregation from a liquid suspension, as well as electrostatics to form coin cell-sized pucks. In block (1206), innate carbon particles may be formed. In block (1208), sp of carbon during formation 2 / sp 3The ratio can be optimized to correspondingly increase lithium (Li) insertion and / or intercalation. In block (1210), impurity contamination, such as that caused by acetylene and other post-plasma aromatics, can be reduced. In block (1212), post-processing operations can be performed.

[0412] FIG. 13 illustrates a schematic diagram showing an ideal anode (1300) configuration having a 3D graphene-based nanostructure (1302) incorporated internally to provide structural definition to the anode (1300) according to some implementations. The 3D graphene-based nanostructure (1302) may be incorporated into or provide structural definition to any one or more of the currently disclosed carbon-based structures including pores (105F) and / or continuous paths (107F), both of which are illustrated in FIG. 1f, or may possess a metal dopant such as silicon (Si) (1312) to create a surface-activated diffusion path (1316) to handle volume expansion during the Li-ion (1306) alloying-de-alloying cycle and limit the inflow of electrolyte. As illustrated in path (1310), silicon can be distributed in path (1308) to a binder (1304), such as high-polarity polyacrylonitrile (PAN), as well as redistributed into defects, pores, or wrinkles of the few-layer graphene sheet. Sulfur (S) doping is performed or occurs in the graphene (1314) on the silicon contact area or surface to support Li ignition in the Li₂S battery system and associated charge-discharge cycles to achieve one or more of the performance figures cited herein, including a specific capacity greater than 372 mAh / g, which can generally be achieved as a theoretical maximum with graphite alone. In some implementations, graphene oxide may be used in addition to or alternative to the few-layer graphene, and the Li₂S system may be immersed in a LiPF6 liquid electrolyte.

[0413] The anode (1300) may be composed of existing or future carbon-based materials that provide backward compatibility. The surface-activated diffusion pathway (1316) may host Li metal, while Li may also be intercalated between pairs of few-layer graphene sheets. The pore size of the carbon material may be tuned in the anode (1300) to achieve a specific distribution or level of inhibition of Li and Li ion flow reversibility, and may be produced as an amorphous or crystalline carbon structure.

[0414] Pre-lithiation of the anode (1300) may initially involve electrochemical or direct contact with molten Li metal, and may later transition to direct vapor injection technology. The carbon structure used as a forming material to constitute the anode (1300) may be deposited as a film of particles or directly from powder, substantially as previously described. The Li efflux rate may be matched with the Li insertion rate within the anode (1300) to prevent excessive Li deposition or condensed carbon surfaces exposed to the incoming Li. And production and cost metric considerations for the anode (1300) may include the following:

[0415] Producing carbon-based materials as low-cost powders rather than films configured for inclusion in the manufacture of existing Li-ion or Li-S batteries;

[0416] A carbon-based film is directly deposited onto a drum regardless of the binder; and

[0417] Carbon can be purified or dried by using lithium injection and evaporation techniques on carbon-based particles and structures such as slurry cast films / binders.

[0418] The Li injection of the anode (1300) may include the following procedures established by known roll-to-roll furnace brazing and / or spontaneous infiltration techniques, which include any one or more of the following:

[0419] Use a two-dimensional (2D) analog with a 2D liquid gap filler;

[0420] Chemical reaction between liquid and solid using flux for activation;

[0421] Increasing the ratio of solid to viscous surface area and decreasing the ratio of liquid to viscous surface area to control and tune surface tension and / or thermodynamic driving force; and

[0422] To decompose the formed lithium oxide (Li2O), Li wettability is screened into a Li foil / carbon particle stack on a hot plate using a halogen intermediate layer.

[0423] The injection of Li into the anode (1300) may also include the following procedure, technique, or implementation involving the evaporation of Li on a metal foil configured to act as a thermal conductor:

[0424] Selection of copper (Cu) for use as a current collector in a Li-ion or Li-S battery system including an anode (1300);

[0425] Tantalum (Ta) interspersed within the anode (1300) for lithium ion release minimizes overall chemical interactions; and

[0426] Creation of a carbon-based film thickness corresponding to the pore volume of packed particles.

[0427] Furthermore, the Li injection of the anode (1300) may also include the following procedure, technique, or implementation related to the orientation of Li and Ta on top of carbon particles packed in a bed configuration that can be prepared to receive a load or pressure provided by a calender roll type drum rotating under dry chamber environmental conditions:

[0428] Forward rotation of a calender roll or drum wrapped in a Ta foil layer additionally wrapped in Li foil compresses carbon particles prepared as a thin layer of material, which applies heat to the calender roll and Cu foil placed on the copper foil to melt Li and produce molten Li metal that penetrates into the carbon particles;

[0429] Creation of total isothermal conditions, such as approximately 180°C just below the Li melting point, across the infiltrated Li and packed carbon particles;

[0430] Observation of a sharp thermal spike at a concentrated Li load location; and

[0431] Li infiltration via an exothermic reaction with capillary-driven molten Li metal fluid flow in a porous carbon medium is subject to one or more Darcy laws, Washburn equations, etc., with variable permeability, and the process is assumed to have no detectable reaction product formation or accumulation.

[0432] Furthermore, the Li injection of the anode (1300) may also include the following procedures, techniques, or implementations:

[0433] Coat a metal, such as copper (Cu) and / or tantalum (Ta) foil, with lithium Li in a vacuum evaporator; control the volume of Li, such as thickness and density, corresponding to the pore volume of the packed carbon particle layer or film;

[0434] Carbon particles are assembled into a packed film without a binder, but a binder option can be considered assuming there is no interaction with molten Li and the proposed binder can be easily removed after Li infiltration.

[0435] Enlargement and / or generation of film-like granular carbon materials from carbon microparticles, such as by tumbling, pressure compression, thermal reaction, fusion, drying, aggregation from liquid suspension, and electrostatic generation to create puck-shaped coin cell-sized structures;

[0436] Collect or screen the aforementioned substances within the reactor.

[0437] Perform post-microwave sintering or fusion; and

[0438] Partial compression is performed with a carbon die and an independent puck or tablet.

[0439] The formation of native carbon particles of a few-layer graphene and other carbons used to form the anode (1300) may include the following:

[0440] sp to increase lithium insertion / intercalation 2 and / or sp 3 Optimizes carbon structure formation; and

[0441] Reduction of impurity contamination, such as acetylene and other post-plasma aromatic substances.

[0442] Post-processing methods may include the following:

[0443] Washing such as aromatic removal;

[0444] Baking carbon at approximately 500°C for approximately 3 hours to remove adsorbed moisture and / or oxygen; and

[0445] Nitrided and / or treated carbon with silicon monoxide.

[0446] Factors affecting Li penetration into the carbon structure of the anode (1300) may include the following:

[0447] Precursor volume;

[0448] Melting temperature such as approximately 180°C to 380°C;

[0449] Particle post-treatment, such as carbon surfaces exposed to contact with Li;

[0450] Mechanical pressure;

[0451] Graphene properties such as a small number of layers or sheet sizes;

[0452] Carbon structural morphology including pore size, volume, and distribution; and

[0453] Surface activation.

[0454] Carbon structure reactions to Li infiltration may include the following:

[0455] Voluntary infiltration;

[0456] Accumulation of excess Li material to achieve a balanced mass in proportion to the Li input amount; and

[0457] The degree of penetration based on the ratio of the carbon surface area exposed to incoming Li to the total volume of the carbon structure.

[0458] FIG. 14 illustrates silicon and carbon (Si-C) anode performance comparing anode specific capacities in mAh / g for a number of charge-discharge cycles according to some implementations. The various series illustrated, including (426, 459, 462, 486, 487, and 401), may include any one or more of the carbon structures illustrated in FIG. 1a through 1f incorporated within the anode (1300) illustrated in FIG. 13 or a Li-ion or Li-S system anode. As illustrated, the carbon structures disclosed herein can uniformly yield specific capacities significantly higher than 372 mAh / g, which is generally associated with graphite anodes.

[0459] FIGS. 15 and 16 illustrate schematic diagrams relating to the ideal cathode configuration (1500) shown in FIG. 15, characterized in that lithium sulfide (Li2S) nanoparticles dispersed in a graphene sheet are bonded by a PAN-type binder and immersed in a LiTFSI electrolyte solution to provide ease of Li ion transport and electrical conductivity, as well as the mitigation and control of polysulfide (PS) generated during charge-discharge cycles of a Li2S battery system according to some implementations. The ideal cathode configuration (1500) may be partially implemented in any one or more of the currently disclosed carbon structures, including forming the pores (105F) and / or continuous microstructure (107F) shown in FIG. 1f in a Li2S battery system. FIG. 16 illustrates an exemplary in-situ 3D nanostructured few-layer graphene material (1600) that may be incorporated to provide structural definition to any one or more of the currently disclosed carbon structures. In some embodiments, a stack of few-layer graphene sheets (1602) may comprise milled sulfur-impregnated graphene heated in a two-stage high temperature (HT) process at 250°C and 350°C. The stack of few-layer graphene sheets (1602) may be infiltrated by Li, such as by lithium triethylborohydride (LiEt3BH) in a THF solution or n-butyllithium provided in an inert argon (Ar) atmosphere, thereby providing a Li source (1604) by any one of the aforementioned Li infiltration techniques. The Li infiltration stack of few-layer graphene sheets (1602) may undergo HT vacuum treatment at 110°C for 10 hours to form in situ Li2S in pores such as the pore (105F) shown in FIG. 1f, where such Li2S is involved in the Li2S electrochemical premise functioning as previously described.

[0460] FIG. 17a illustrates an enlarged cutaway perspective view of carbon-based particles (100A, 100E) and / or similar ones. Individual ligaments (1702A) formed as discussed in relation to the carbon-based particles (100A) shown in FIG. 1a through 1f may be extended to form a lattice and / or tree-branched structure of the section (1700A) where Li ions (Li+) (1704A) can be intercalated, which can be inserted between individual gradient layers of the section (1700A) containing 3D bundles of the graphene sheet (101B). Current may be conducted through the flow of electrons through the region and / or contact surface between the interconnected 3D bundles of the graphene sheet (101B). Li ions can flow through pores (1710A) that can be scaled to a larger size of bimodal distribution of pores or pores as described in Figs. 1a to 1f, or generally confined through chemical micro-confinement into pores of about 1 to 3 nanometers in size.

[0461] Accordingly, the Li ion flow must be finely controlled or tuned in the carbon-based particles (100A) to be opposite to the electron flow as needed to facilitate the electrochemical gradient that may be required for electrical conduction and / or electron flow through the contacts and / or regions of the 3D bundle of, for example, the graphene sheet (101B). The spacing between individual carbon-based ligaments can be set to 0.1 µm. Those skilled in the art will understand that the dimension of 0.1 µm is provided merely as an example and that other suitable similar or dissimilar dimensions may exist in the section (1700A) of the carbon-based particles (100A).

[0462] Section (1700A) can be formed of 3D bundles of graphene sheets (101B) sintered together to form a configuration without completely open channels, so that electricity is necessarily conducted through the contacts and / or regions of the interconnected 3D bundles of graphene sheets (101B). Thus, the conductive properties of the liquid passing through the voids (1704A) and the carbon-carbon bonds allow carbon-based materials to be easily connected to other carbon-based materials without the need for chemical binders and / or chemical bonding agents or agents, many of which result in undesirable chemicals or side effects in relation to the functionality of the carbon-based particles (100A).

[0463] An open porous scaffold (102A) of carbon-based particles (100A) presents a departure from traditional industrial standard battery electrodes that may include slurry-molded boulders, which are relatively large particles randomly organized on a substrate, and such boulders generally require a binder that must be held together to conduct electricity through them. The open porous scaffold (102A), defined by hierarchical pores (101A) and / or adjacent microstructures (107F) of carbon-based particles (100A), allows for improved electrical conductivity within.

[0464] FIG. 17b illustrates the carbon-based particles of FIG. 17a having graphene-on-graphene densification. For the example of FIG. 17b, the surface (1700B) shown in FIG. 17b and / or the surface (1708A) shown in FIG. 17a at the edge region, at least partially planar surfaces of the branched tree-like structure of the carbon-based particle (100A) section (1700A), are densified upon application, deposition, or growth of multiple additional graphene layers. Such densification processes, methods, and / or procedures allow for the creation of complex, multilayered, and potentially nearly infinitely tunable 3D carbon structures comprising combinations of 3D bundles of graphene sheets (101B). Thus, this fine-tunability achieved by graphene-on-graphene densification can facilitate the achievement of specific electrical conductivity values ​​when the carbon-based particles (100) are incorporated into the electrodes of a battery.

[0465] FIGS. 18a through 18c illustrate any one or more actual micrographs (1800A, 1800B, 1800C) of the currently disclosed carbon structures and include carbon-based particles (100A) and / or adjacent microstructures (107F) respectively illustrated in FIGS. 1a and 1f at various levels of magnification.

[0466] FIG. 18d illustrates a micrograph (1800D) of a composite carbon aggregate having an internal structure similar to that described for a carbon-based particle (100A) having pores (105F) and a continuous microstructure (107F), and although the size and composition are both formulated for integration into a cathode for a lithium-ion system, they can also be applied to processing and producing a cage for Li in an anode. Any one or more of the electrodes currently disclosed can be manufactured using aggregates of any size and shape. Nevertheless, carbon aggregates and / or particles can be produced to a regular expected size through a conditioning procedure, which can potentially provide both ease of handling and processing advantages.

[0467] FIG. 18e shows a micrograph (1800E) of an activated carbon structure for sulfur (S) infiltration used in a Li₂S system cathode described by at least one of the currently disclosed carbon-based structures including the adjacent microstructure (107F) shown in FIG. 1f. The activated carbon structure for sulfur (S) infiltration shown in the micrograph (1800E) can be produced by a combined screw conveyor system or through other distinct steps. The thermal reactor-generated material was found to be more lithium-affinity than the undoped and / or unfunctionalized microwave-generated carbon structure. In some implementations, the diffusion of organic and / or hydrocarbon-based contamination on the surface of the few-layer graphene produced in the reactor may require the performance of an additional post-processing purification step.

[0468] FIG. 19a illustrates a schematic diagram (1900A) of a 3D graphene particle cathode scaffold, such as a carbon scaffold (300B) featuring sulfur (S) micro-confinement suitable for scaling up and / or integration with one or more carbons currently disclosed, including use as a forming material to create the continuous microstructure (107F) illustrated in FIG. 1f. In the example of FIG. 19a, graphene-based sheets and / or structures containing sulfur companionship and / or confinement (1902A) in various 3D cathode scaffold structures or configurations of various thicknesses (1904A and 1906A) are illustrated. Including S in graphene-based battery chemistry provides desirable charge storage and retention measured in milliampere-hours, which is further illustrated by the synthesis of a graphene-sulfur composite material by wrapping poly(ethylene glycol) (PEG)-coated submicrometer sulfur particles in a slightly oxidized graphene oxide sheet decorated with carbon black nanoparticles.

[0469] PEG and graphene coating layers are important for accommodating the volumetric expansion of coated sulfur particles during discharge, trapping soluble polysulfide intermediates, and making the sulfur particles electrically conductive. The resulting graphene-sulfur composites exhibit high and stable specific capacities of up to ~600 mAh / g over more than 100 cycles, representing promising cathode materials for rechargeable Li batteries 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 applied as a sulfur matrix. The influence of AG pore structure parameters and sulfur loading on the electrochemical performance of lithium-sulfur batteries has been systematically investigated.

[0470] The results demonstrate that the battery's specific capacity, cycling performance, and Coulomb efficiency are closely related to the pore structure and sulfur load. An AG3-sized (S) composite electrode with a high sulfur load of 72 wt.% exhibited excellent long-term cycling stability with 50% capacity retention over 1,000 cycles and an ultra-low capacity fade rate (0.05% per cycle). Furthermore, when LiNO3 was used as an electrolyte additive, the AG3 / S electrode exhibited similar capacity retention of ~98% and high Coulomb efficiency over 1,000 cycles. The superior electrochemical performance of the series of AG3 / S electrodes is attributed to the mixed micro / mesoporous structure, high surface area, excellent electrical conductivity of the AG matrix, and sulfur well distributed within the micro / mesopores, which is advantageous for electrical and ion transport during cycling.

[0471] FIG. 19b illustrates a 3D few-layer graphene anode scaffold, such as a carbon scaffold (300) and / or a lithiated carbon scaffold (400A), prepared for use as an integrated or forming material inside a Li-ion or Li-S system anode in which Li is intercalated between graphene layers. In the example of FIG. 19b, Li ions (Li+) are intercalated into FLG (1902B) and are illustrated in various configurations (1900B) including the reversible inclusion of Li metal in a carbon-based host scaffold (1904B). Li intercalation into bilayer graphene is related to and can resolve the Li storage process in graphite, which poses issues regarding the actual capacity of graphene and the field of Li-ion batteries.

[0472] The various physicochemical properties of stepwise lithium bilayer graphene products, confirmed by theoretical calculations, further exhibit regular Li-intercalation phenomena, thereby perfectly illustrating this fundamental two-dimensional lithium storage pattern. These findings not only establish commercial graphite as a primary electrode with a distinct lithium storage process but also guide the development of graphene materials in lithium-ion batteries. The lithium absorption and intercalation of single-layer and few-layer graphene differ from those associated with bulk graphite. For single-layer graphene, the cluster expansion method is used to systematically search for the lowest energy ion configuration as a function of absorbed Li content. Unless defects are present on the single-layer graphene surface, it is predicted that no Li arrangement exists to stabilize Li absorption on the single-layer graphene surface. From these results, it can be seen that poor single-layer graphene exhibits significantly inferior capacity compared to bulk graphite.

[0473] In some embodiments, the carbon-based particle film may include at least the following particle-like properties in addition to any one or more of the following: sacrificial and support film substrates; adjustable velocity relative to the substrate; adjustable impact energy from injection to adsorption; adjustable thickness; and adjustable porosity; one or more of these may be integrated with a stacking fabrication function.

[0474] In some embodiments, any one or more of the currently disclosed carbon and carbon-based structures can significantly improve battery performance compared to currently available Li-ion and / or Li-S batteries, including: approximately 400 to 650 (W To achieve any one or more of physical and / or electrical energy storage and / or conductivity values ​​including energy density in the range of h ) / kg, a maximum theoretical value of 850 (W h) / kg, also in aspect where the sulfur and / or sulfur intercalation cathode is 650 (MAh) / g, and in aspect of intercalation of conductive carbon particles and / or graphene sheets (102A) interspersed to define pores and / or voids, etc. as substantially discussed in relation to those illustrated in FIGS. 1a to 1f, or ionic Li(Li+) is ultimately intercalated internally to achieve an energy density storage value of 900 to 2,000 (mAh) / g.

[0475] FIG. 20a illustrates cathode specific capacity levels according to cycles and various representative sulfur-nano confinement, representing the application and / or use of systems based on or using diagrams and images of carbon-based particles (100A) and their derivatives. Improved cathode specific capacity, electrode levels measured in mAh / g are shown in graph (2008a) for various compositions and / or compounds, any one or more of which at least partially comprise carbon-based particles (100A) formed by incorporating s to improve cathode specific capacity.

[0476] FIGS. 20b and 20c show charts regarding accelerated carbon tuning to mitigate polysulfide (PS) shuttle-related problems, indicating that increasing the porosity of carbonaceous materials, carbonaceous particles (100A), and their variations reduces PS shuttle, which is defined as sulfur S reaching the cathode surface and undergoing chemical reduction to cause unwanted auto-electrochemical cell self-discharge. The chart (2002B) shown in FIG. 20b shows the average intensity change of low-porous carbon at a level generally higher than that of high-porous carbon. The chart (2002C) shown in FIG. 20c indicates high-porous carbon having a higher percentage of capacity retention over repeated battery usage cycles compared to low-porous carbon.

[0477] Adjustment of the carbon-based particles (100A) can achieve more efficient manufacturing, including lithium utilization, and can achieve a potential increase in the ratio of active material to inactive material within the battery electrode, a reduction in binder, improved uniformity, and controlled electrochemical reactions such as battery electrical conductivity and / or activity. The parameters of the carbon-based particles (100A) can be adjusted to achieve specific performance characteristics as a function of the percentage of Li loading per unit area or volume of the carbon-based particles (100A), including:

[0478] Compensates for sub-capacity at low load levels, primary charge loss / more effective SEI formation; Li-rich regions galvanically bonded to carbon at saturated / matched loading,

[0479] Oxidizing the material upon contact with the electrolyte and insertion of Li and / or Li ions through intercalation between graphene layers;

[0480] Under excessive load levels, metallic Li infiltrates the engineered host carbon; the host is configured to accommodate / stabilize the expansion of Li and suppress dendrite formation as a result of the increased Li surface area, thereby enabling a specific capacity equivalent to pure Li: > 2,000 mAh / g; and,

[0481] A lithium-ion process / method capable of direct transfer to a lithium-ion hybrid capacitor is prepared.

[0482] Ongoing issues regarding the thermal and / or liquid injection of Li and / or Li ions into carbon-based structures, such as carbon-based particles (100A) as summarized in Listing 2900E, may include the management of Li reactivity regarding surface tension and wettability at the solid-liquid electrolyte interface; the management of capillary Li and / or S penetration kinetics; the engineering of the electrical gradient through the electrode thickness; the gradient of Li penetration so that it is highest at the current collector and transitions to a higher ionic conductivity concentration and / or level at the electrolyte interface; and the carefully tuned engineering of surface chemistry to promote stable SEI formation in contact with the electrolyte and minimize reactivity with air.

[0483] The disclosed embodiment may be based on traditional two-dimensional (2D) plating, which may be similar to a brightener in electroplating. In electroplating, the addition of chemical additives can often increase polarization and decrease current density; for example, redirect the current density toward a lower direction rather than a high region such as a protrusion; generate a relatively high nucleation rate and result in a moderate charge transfer rate. In the case of a battery with an electrode equipped with carbon-based particles (100A) shown in FIGS. 1a through 1f in relation to plating or stripping for battery charge and discharge cycles, the carbon film can not only serve as a flexible support for SEI formation but also redirect the current density toward a lower region rather than a high region.

[0484] Cementation, employed herein in the context of generating carbon-based particles (100A) and integrating them into a Li-ion battery, may be used in any one or more of the disclosed manufacturing techniques. Cementation refers to a process of altering a metal by heating it in contact with a powdered solid, and the precipitation of copper production may refer to or involve a heterogeneous process. Such a process may refer to conditions where the reactants are composed of two or more phases, such as solid and gas, solid and liquid, or two immiscible liquids, or where one or more reactants undergo a chemical change at the interface of a solid catalyst surface, where, ions on a solid metal surface, such as Cu ions on the surface of Fe particles, are reduced to zero; and where iron is oxidized and copper is reduced, for example, copper is relatively higher in the galvanic series, which is similar to Li versus C.

[0485] Molten metal containing Li metal may be managed for welding so that any one or more of the mentioned techniques can be functionally integrated and / or carbon-based particles (100A) can be generated to be used to improve Li-ion or Li-S battery performance. These auxiliary processes and / or techniques include: managing reactive metal through welding; gas tungsten arc welding (GTAW), also known as conventional metal inert gas (MIG) and tungsten inert gas (TIG); and submerged arc welding (SAW), which joins reactive metals such as Ti and Al through liquid metal processes such as welding using an inert shielding gas. Examples include forming a liquid pool of reactive metal without oxidation using an inert shielding gas, wherein the delta Gf of oxides such as TiO2 and Al2O3 is equivalent to that of Li2O. By using an inert shielding gas in a controlled manner around the reactive metal, oxygen and moisture can be effectively managed in the presence of the reactive liquid metal. Under these environments and conditions, liquid Li can penetrate the carbon-based structures of carbon-based particles (100A) through controlled shielding gas configuration and operation.

[0486] FIG. 21 illustrates the Raman spectrum for 3D N-doped FL graphene, including charts for both raw carbon and N-doped carbon. In the example of FIG. 21, the Raman spectrum for 3D N-doped FL graphene (2100) shows a 2D peak (2102) at approximately 2730 cm⁻¹ and at approximately 1600 cm⁻¹, respectively. -1 and 1400cm -1 Each includes D peaks (2104, 2106).

[0487] FIG. 22 illustrates various properties associated with bilayer graphene (2200). In the example of FIG. 22, the sample bilayer graphene base structure (2200) is shown with two graphene layers oriented at the illustrated positions, which is understood as a device containing 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 occur in the defined vicinity of the edge plane and / or may aid in the creation of a carbon-based particle structure containing one or more graphene sheets. Schematic diagram (2210) shows various model diagrams (2212) of a plan view of a rigid spherical carbon particle model.

[0488] In some implementations, reactor tuning may be performed by any one or more of the following: e.g., increasing FL graphene spacing, decreasing van der Waals forces; controlling doping; promoting carbon defect formation; and decreasing Li adsorption energy and / or increasing Li capacity. Li ion intercalation can, for example, shift a graphene sheet stack from an AB configuration to an A configuration, where the intercalation is accommodated by increased spacing, where, for example, in graphite, it can be shifted back to AB through deintercalation, and in FL graphene, the AA stacking is maintained by deintercalation, for example, by maintaining increased spacing. Such stacked configurations may be associated with carbon-based particles (100A) shown in FIGS. 1a through 1f.

[0489] FIG. 23 illustrates an exemplary flowchart for describing an exemplary operation (2300) for manufacturing a 3D scaffolded film containing carbon-based particles. In the example of FIG. 23, the method (3300) includes the step of preparing a 3D scaffolded film containing carbon-based particles in operation (2304) by providing the 3D scaffolded film to a roll-to-roll processing device or apparatus in operation (2306). A carbon-rich electrode may be deposited on the 3D scaffolded film in operation 2308; the step of processing the 3D scaffolded film on the roll-to-roll processing device or apparatus regardless of the application of a chemically inert bonding material may occur in operation (2310) before the method (2300) is terminated in operation (2312).

[0490] One innovative aspect of the subject matter described in the present disclosure may be realized as a lithium (Li) ion battery comprising an anode, a cathode positioned opposite the anode, a porous separator positioned between the anode and the cathode, and a liquid electrolyte in contact with the anode and the cathode. The anode comprises an electrically conductive substrate. A first film is deposited on the electrically conductive substrate. The first film comprises carbon particles of a first concentration in contact with each other, configured to define a first electrical conductivity for the first film. Each carbon particle comprises a plurality of aggregates made of a few-layer graphene sheet. The plurality of aggregates forming a porous structure are configured to undergo lithiation.

[0491] Lithium-lithiation may include any one or more of intercalation operations or plating operations. The anode and cathode may each include an electroactive material. The porous structure is configured to provide electrical conductivity between the contacts of the few-layer graphene sheets. The porous structure may be configured to contain molten Li metal. The porous structure may be configured to accommodate a liquid electrolyte that may be configured to facilitate the transport of multiple Li ions within the porous structure.

[0492] A second film may be deposited on a first film. The second film may contain carbon-based particles of a second concentration. The carbon-based particles of the second concentration are configured to provide a second electrical conductivity for the second film that is lower than the first electrical conductivity. The electroactive material may be present in the pores of one or both of the anode and the cathode. The electroactive material is approximately 1,635 m 2 / g to 2,675m 2 It may have a specific surface area (SSA) of / g. The electroactive material may comprise any one or more of pre-lithiated few-layer graphene (LLG) sheets, pristine graphene, graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide, graphene iodide, graphene hydrogenate, graphene nitrate, boron-doped graphene, nitrogen-doped graphene, chemically functionalized graphene, physically or chemically activated or etched versions, sulfur-doped graphene, or electrically conductive polymer-coated or grafted versions thereof.

[0493] The porous structure may be defined by an aggregate independent of the binder and may be configured to be formed substantially spherically having any one or more dimensions in the range of 1 to 30 µm, < 50 µm, or greater than 500 nm. The porous structure may include an active Li intercalating structure configured to incorporate silicon (Si). The active Li intercalating structure may have a specific capacity between approximately 730 and 3,600 mAh / g. The chemically functionalized graphene may include functional groups selected from combinations thereof comprising functional groups configured to react with or include one or more of quinone, hydroquinone, quaternized aromatic amine, mercaptan, disulfide, sulfonate (-SO3), transition metal oxide, transition metal sulfide, or magnesium (Mg), calcium (Ca), aluminum (Al), strontium (Sn), and zinc (Zn).

[0494] The electrically conductive substrate may be a current collector that is at least partially foam-based or foam-derived, and is selected from any one or more of metal foam, metal web, metal screen, perforated metal, sheet-based 3D structure, metal fiber mat, metal nanowire mat, electrically conductive polymer nanofiber mat, electrically conductive polymer foam, electrically conductive polymer coated fiber foam, carbon foam, graphite foam, carbon aerogel, carbon zerogel, graphene foam, graphene oxide foam, reduced graphene oxide foam, carbon fiber foam, graphite fiber foam, and exfoliated graphite foam.

[0495] The current collector may be formed as a foil. The electroactive material may include one or more of nanoparticles, nanodiscs, nanoplates, nanocoatings, or nanosheets of inorganic materials. The nanoparticles, nanodiscs, nanoplates, nanocoatings, or nanosheets of inorganic materials may be selected from bismuth selenide or bismuth telluride, transition metal dichalcogenides or trichalcogenides, sulfides, selenides or tellurides of transition metals, boron nitride, or combinations thereof, wherein the nanoparticles, nanodiscs, nanoplates, nanocoatings, or nanosheets have a thickness of less than 100 nm.

[0496] Another innovative aspect of the subject matter described in this disclosure may be realized as an electrochemical cell electrode comprising a film layer deposited on an electrically conductive substrate. The film layer comprises an aggregate of carbon of any concentration formed from a plurality of few-layer graphene sheets orthogonally fused, and a porous structure defined by the plurality of few-layer graphene sheets. The porous structure is composed of any one or more of providing electrical conductivity between contacts between any two or more of the plurality of few-layer graphene sheets or hosting an electroactive material.

[0497] One or more adjacent pairs of graphene sheets among a plurality of few-layer graphene sheets may comprise a first graphene sheet and a second graphene sheet separated by a D-spacing of 3 Å to 20 Å. The electrochemical cell electrode may comprise an anode, wherein the electroactive material comprises elemental lithium (Li) interspersed in the D-spacing of the anode. A plurality of Li ions are provided by elemental Li.

[0498] An additional film is deposited on the film. The film is configured to provide a first electrical conductivity, and the additional film is configured to provide a second electrical conductivity different from the first electrical conductivity.

[0499] The porous structure may include a plurality of interconnected channels configured to allow the liquid electrolyte to penetrate. Both the first electrical conductivity and the second electrical conductivity may be directly proportional to the migration of a plurality of Li ions provided by the electroactive material in the liquid electrolyte. The migration may be directed toward an additional electrochemical cell electrode positioned substantially opposite to the electrochemical cell electrode. The plurality of interconnected channels may be configured to prevent the accumulation of Li ions on any one or more of the electrochemical cell electrode or the additional electrochemical cell electrode.

[0500] The porous structure may include any one or more of intermediate-scale structuring or micron-scale fractal structuring. The electroactive material may include molten Li metal, which can be configured to be injected into the porous structure.

[0501] The porous structure may be configured to be permeated by an electrolyte that may be configured to transport Li ions. The porous structure may be configured to be permeated by an electrolyte in any one or more of a liquid phase or a gel phase. The electrolyte may be any one or more of a polymer phase or a substantially solid electrolyte interface phase that may contain a solid-state electrolyte, and may be configured to at least substantially prevent or mitigate any one or more of the formation of Li dendrites, the formation of a short circuit, or leakage of the solid electrolyte.

[0502] The solid-state electrolyte may be selected from any one or more of a solid polymer electrolyte, a gel polymer electrolyte, or a non-polymer electrolyte. The solid-state electrolyte may comprise a Li salt dissolved in a polymer host, which may comprise one or more of polyethylene glycol (PEO), polyvinylidene fluoride or polyvinylidene difluoride (PVDF), poly(p-phenylene oxide) (PPO) or poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), poly(methyl methacrylate) (PMMA), polystyrene sulfonate (PSS) and salts of these polymers (Li or Na salts), PAN, and PANI.

[0503] Substantially, the solid electrolyte interface may comprise one or the other of a liquid component trapped in a polymer matrix or a non-polymer solid electrolyte. The liquid component is configured to facilitate Li ion transport. The non-polymer solid electrolyte is a Li superion conductor (LISICON) or a garnet-type Li7La3Zr2O 12It may include any one or more of a ceramic nanofiber-incorporated composite including (LLZO), and a calcium titanium oxide mineral composed of calcium titanate including perovskite. The non-polymer solid electrolyte may have a thickness in the range of approximately 0.5 µm to 40 µm. The thickness may be configured to substantially prevent any one or more of the formation or growth of Li dendrites.

[0504] The porous channel structure may include a first part configured to provide a Li ion conduit, a second part configured to facilitate rapid Li ion transport, and a third part configured to confine an electroactive material. The electrical conductivity is in the range of about 1,000 S / m to about 20,000 S / m.

[0505] One or more additional film layers may be deposited on the film layer, and any one or more of them are configured to provide electrical conductivity that is proportionally reduced to that of the immediate film layer in a direction substantially orthogonal to the electrically conductive substrate.

[0506] A solid electrolyte interface (SEI) may be formed near the porous structure. The electrochemical cell may further include an artificial solid electrolyte interface (ASEI) located near the porous structure. The ASEI is formed in situ during the formation of the porous structure or is formed ex situ as any one or more of a coating, film, or reactant.

[0507] The porous structure may include one or more lithium-affinity functionalized surfaces that can be configured to provide Li adsorption centers.

[0508] One innovative aspect of the subject matter described in the present disclosure may be implemented as a method for manufacturing an anode. The method comprises the steps of: nucleating a plurality of carbon particles at a first concentration level; forming a first film on a sacrificial substrate based on the first concentration level; defining a porous structure based on a plurality of graphene sheets, wherein each carbon particle is defined by a plurality of aggregates formed of a few-layer graphene sheet fused together; and injecting molten lithium (Li) metal into the porous structure.

[0509] A plurality of interconnected porous channels may be defined based on a plurality of carbon particles. A second film may be formed by nucleation of carbon particles at a second concentration level on a first film. The first film may be configured to provide a first electrical conductivity, and the second film may be configured to provide a second electrical conductivity different from the first electrical conductivity. The second electrical conductivity may be lower than the first electrical conductivity.

[0510] The first film may have an average thickness in the range of approximately 10 μm to approximately 200 μm. Carbon particles may be grown in a roll-to-roll processing device. The method may include any one or more of the steps of evaporating molten Li metal onto a metal foil and rolling the molten Li metal from the metal foil into a porous structure. The method may include the steps of preparing a cathode and an anode to participate in the reversible migration of Li ions, prepared by any one or more chemical functionalizations or sulfidation, and densifying a plurality of graphene sheets on the porous structure.

[0511] Other aspects of the subject matter described in the present disclosure may be implemented as a process for manufacturing a lithium (Li) ion battery anode. The process may include the steps of depositing a first plurality of carbon particles on a substrate and forming a first film configured to provide a first electrical conductivity based on the first plurality of carbon particles. Each of the first plurality of carbon particles may comprise a plurality of 3D aggregates formed of a few-layer graphene sheet configured to orthogonally fuse together and define a porous structure. A porous array is formed in the porous structure. Molten Li metal is injected into the porous structure. The process may include any one or more of the steps of depositing a second plurality of carbon particles on the first film and forming a second film configured to provide a first electrical conductivity based on the second plurality of carbon particles.

[0512] The molten Li injection rate can be selected according to the viscous resistance of the molten Li. The molten Li metal may be configured to react with any one or more of the first plurality of carbon particles to produce a carbide. The process may include any one or more of the steps of infiltrating the molten Li metal into the porous structure in a vapor phase, initiating a chemical reaction between any one or more Li ions provided by the molten Li metal and one or more exposed surfaces of the porous structure, and forming one or more lithium-affinity surfaces from one or more exposed surfaces.

[0513] The process may include coating any one or more of the lithium-affinity surfaces with an active element comprising any one or more halogens or metal oxides. The process may include the steps of coating any one or more of the lithium-affinity surfaces with any one or more elements having a surface energy lower than Li, and promoting the improvement of Li wetting on any one or more of the lithium-affinity surfaces with any one or more elements having a surface energy lower than Li.

[0514] The process may include the step of creating a binder by incorporating any one or more of metal-containing compounds, including metal powder or silicon carbide (SiC), into a carbon preform. Li wetting may include interfacial surface tension engineering. In some embodiments, Li wetting involves one or more chemical reactions at the interface of Li and at the exposed surface of the porous structure. Li wetting enhancement may include the step of adding a certain amount of dopant at the interface and any one or more of influencing the degree of Li wetting corresponding to the amount of dopant. Adsorption of hydroxyl (OH) or hydroxyl (OH) groups may be controlled on any one or more of the exposed surfaces of the porous structure.

[0515] In the foregoing specification, the present disclosure has been described with reference to specific examples. However, it will be apparent that various modifications and changes may be made without departing from the broader spirit and scope of the present disclosure. For example, the process flow described above is described with reference to a specific sequence of process operations. However, many sequences of the described process operations may be changed without affecting the scope or operation of the present disclosure. The present specification and drawings should be considered in an illustrative sense rather than a restrictive sense.

[0516] The following are additional examples of innovative embodiments included in the present disclosure:

[0517] 1. As a lithium (Li) ion battery,

[0518] Anode;

[0519] A cathode positioned opposite the above anode;

[0520] A porous separator located between the anode and the cathode; and

[0521] It comprises a liquid electrolyte in contact with the anode and the cathode, wherein the anode is:

[0522] Electrically conductive substrate; and

[0523] A lithium-ion battery comprising a first film deposited on an electrically conductive substrate, wherein the first film comprises carbon particles of a first concentration configured to contact each other and define a first electrical conductivity for the first film, each of the carbon particles comprises a plurality of aggregates formed of a few-layer graphene sheet, and the plurality of aggregates form a porous structure configured to undergo lithiation.

[0524] 2. A lithium-ion battery according to Example 1, wherein the lithiation step comprises any one or more of an intercalation operation or a plating operation.

[0525] 3. A lithium-ion battery in which, in any one of the preceding examples, the anode and the cathode each comprise an electroactive material.

[0526] 4. A lithium-ion battery, wherein, in any one of the prior examples, the porous structure is configured to provide electrical conductivity between the contacts of the few-layer graphene sheets.

[0527] 5. A lithium-ion battery, wherein, in any one of the preceding examples, the porous structure is configured to include molten Li metal.

[0528] 6. In any one of the preceding examples, the porous structure is configured to accommodate a liquid electrolyte, in a lithium-ion battery.

[0529] 7. A lithium-ion battery, wherein, in any one of the prior examples, the liquid electrolyte is configured to facilitate the transport of a plurality of Li ions within the porous structure.

[0530] 8. A lithium-ion battery comprising, in any one of the prior examples, a second film deposited on the first film, wherein the second film comprises carbon-based particles of a second concentration.

[0531] 9. A lithium-ion battery, wherein in any one of the preceding examples, the carbon-based particles of the second concentration are configured to provide a second electrical conductivity to the second film that is lower than the first electrical conductivity.

[0532] 10. A lithium-ion battery in which, in any one of the preceding examples, the electroactive material is present in the pores of one or both of the anode and the cathode.

[0533] 11. In any one of the preceding examples, the electroactive material is approximately 1,635 m 2 / g to 2,675 m 2 A lithium-ion battery having a specific surface area (SSA) of g / g.

[0534] 12. In any one of the prior examples, the electroactive material comprises any one or more of a pre-lithiated few-layer graphene (FLG) sheet, pristine graphene, graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, nitrified graphene, boron-doped graphene, nitrogen-doped graphene, chemically functionalized graphene, physically or chemically activated or etched versions thereof, sulfur-doped graphene, or electrically conductive polymer-coated or grafted versions thereof, a lithium-ion battery.

[0535] 13. A lithium-ion battery, wherein in any one of the preceding examples, the porous structure is defined by the aggregate independent of the binder.

[0536] 14. A lithium-ion battery, wherein, in any one of the preceding examples, the porous structure is configured to be substantially spherical.

[0537] 15. A lithium-ion battery, wherein, in any one of the preceding examples, the substantially spherical porous structure has any one or more dimensions in the range of 1 to 30 µm, < 50 µm, or greater than 500 nm.

[0538] 16. A lithium-ion battery, wherein in any one of the prior examples, the porous structure comprises an active Li intercalating structure configured to incorporate silicon (Si), and the active Li intercalating structure has a specific capacity of about 730 to 3,600 mAh / g.

[0539] 17. A lithium-ion battery in which, in any one of the prior examples, the chemically functionalized graphene comprises a functional group selected from a combination thereof comprising a functional group configured to react with or include any one or more of quinone, hydroquinone, quaternary aromatic amine, mercaptan, disulfide, sulfonate (-SO3), transition metal oxide, transition metal sulfide, or magnesium (Mg), calcium (Ca), aluminum (Al), strontium (Sn), and zinc (Zn).

[0540] 18. A lithium-ion battery, wherein, in any one of the preceding examples, the electrically conductive substrate is a current collector.

[0541] 19. In any one of the prior examples, the current collector is at least partially foam-based or foam-derived and is selected from any one or more of metal foam, metal web, metal screen, perforated metal, sheet-based 3D structure, metal fiber mat, metal nanowire mat, electrically conductive polymer nanofiber mat, electrically conductive polymer foam, electrically conductive polymer coated fiber foam, carbon foam, graphite foam, carbon aerogel, carbon zerogel, graphene foam, graphene oxide foam, reduced graphene oxide foam, carbon fiber foam, graphite fiber foam, and exfoliated graphite foam, a lithium-ion battery.

[0542] 20. In any one of the preceding examples, the lithium-ion battery, wherein the current collector is formed of foil.

[0543] 21. A lithium-ion battery, wherein, in any one of the prior examples, the electroactive material comprises one or more of nanoparticles, nanodiscs, nanoplates, nanocoatings, or nanosheets of an inorganic material.

[0544] 22. In any one of the prior examples, the nanoparticles, nanodiscs, nanoplates, nanocoatings, or nanosheets of the inorganic material are selected from bismuth selenide or bismuth telluride, transition metal dichalcogenides or trichalcogenides, sulfides, selenides, or tellurides of transition metals, boron nitride, or combinations thereof, and the nanoparticles, nanodiscs, nanoplates, nanocoatings, or nanosheets have a thickness of less than 100 nm, a lithium-ion battery.

[0545] 23. In the electrode of an electrochemical cell,

[0546] It comprises a film layer deposited on an electrically conductive substrate, and - the film layer:

[0547] A carbon aggregate of arbitrary concentration formed from a plurality of orthogonally fused few-layer graphene sheets; and

[0548] An electrochemical cell electrode comprising a porous structure defined by the plurality of few-layer graphene sheets and configured to provide electrical conductivity between any two or more contacts among the plurality of few-layer graphene sheets or to host an electroactive material.

[0549] 24. An electrochemical cell electrode, wherein, in any one of the prior examples, one or more adjacent pairs of graphene sheets among the plurality of few-layer graphene sheets comprise a first graphene sheet and a second graphene sheet separated by a D-spacing of 3 Å to 20 Å.

[0550] 25. An electrochemical cell electrode comprising, in any one of the preceding examples, further comprising an anode, wherein the electroactive material comprises elemental lithium (Li) interspersed in the D-spacing of the anode.

[0551] 26. An electrochemical cell electrode comprising, in any one of the preceding examples, a plurality of Li ions provided by the element Li.

[0552] 27. An electrochemical cell electrode comprising, in any one of the prior examples, an additional film deposited on the film, wherein the film is configured to provide a first electrical conductivity and the additional film is configured to provide a second electrical conductivity different from the first electrical conductivity.

[0553] 28. In any one of the preceding examples, the porous structure is:

[0554] An electrochemical cell electrode comprising a plurality of interconnected channels configured to be penetrated by a liquid electrolyte, wherein the first electrical conductivity and the second electrical conductivity are both directly proportional to the migration of a plurality of Li ions provided by the electroactive material in the liquid electrolyte, and the migration is directed toward an additional electrochemical cell electrode positioned substantially opposite to the electrochemical cell electrode.

[0555] 29. An electrochemical cell electrode, wherein, in any one of the preceding examples, the plurality of interconnected channels are configured to prevent the accumulation of Li ions on any one or more of the electrochemical cell electrode or the additional electrochemical cell electrode.

[0556] 30. An electrochemical cell electrode, wherein, in any one of the preceding examples, the porous structure comprises any one or more of a mesoscale structuring or a micron-scale fractal structuring.

[0557] 31. An electrochemical cell electrode, wherein, in any one of the prior examples, the electroactive material comprises molten Li metal.

[0558] 32. An electrochemical cell electrode configured such that the molten Li metal is injected into the porous structure in any one of the preceding examples.

[0559] 33. An electrochemical cell electrode configured such that the porous structure is penetrated by an electrolyte in any one of the preceding examples.

[0560] 34. An electrochemical cell electrode configured such that the electrolyte transports Li ions in any one of the preceding examples.

[0561] 35. An electrochemical cell electrode, wherein, in any one of the preceding examples, the porous structure is configured to be penetrated by the electrolyte in any one or more of a liquid phase or a gel phase.

[0562] 36. An electrochemical cell electrode in which, in any one of the preceding examples, the electrolyte is on any one or more of a polymer phase or a substantially solid electrolyte interface.

[0563] 37. An electrochemical cell electrode in which, in any one of the prior examples, the substantially solid electrolyte interface phase comprises a solid-state electrolyte.

[0564] 38. An electrochemical cell electrode configured such that, in any one of the preceding examples, the solid-state electrolyte substantially prevents or mitigates at least one or more of the formation of Li dendrites, the formation of a short circuit, or leakage of the solid-state electrolyte.

[0565] 39. An electrochemical cell electrode, wherein, in any one of the prior examples, the solid-state electrolyte is selected from any one or more of a solid polymer electrolyte, a gel polymer electrolyte, or a non-polymer electrolyte.

[0566] 40. An electrochemical cell electrode, wherein, in any one of the prior examples, the solid-state electrolyte further comprises a Li salt dissolved in a polymer host.

[0567] 41. An electrochemical cell electrode, wherein, in any one of the prior examples, the polymer host comprises any one or more of polyethylene glycol (PEO), polyvinylidene fluoride or polyvinylidene difluoride (PVDF), poly(p-phenylene oxide) (PPO) or poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), poly(methyl methacrylate) (PMMA), polystyrene sulfonate (PSS) and salts of these polymers (Li or Na salts), PAN, and PANI.

[0568] 42. An electrochemical cell electrode, wherein, in any one of the preceding examples, the substantially solid electrolyte interface comprises one or the other of a non-polymer solid electrolyte or a liquid component trapped in a polymer matrix.

[0569] 43. An electrochemical cell electrode configured such that the liquid component promotes Li ion transport in any one of the preceding examples.

[0570] 44. An electrochemical cell electrode in which, in any one of the preceding examples, the non-polymer solid electrolyte substantially comprises a ceramic material.

[0571] 45. In any one of the prior examples, the non-polymer solid electrolyte is a Li superionic conductor (LISICON), garnet-type Li7La3Zr2O 12 An electrochemical cell electrode comprising any one or more of a ceramic nanofiber-incorporated composite including (LLZO) and a calcium titanium oxide mineral composed of calcium titanate including perovskite.

[0572] 46. ​​In any one of the prior examples, the non-polymer solid electrolyte has a thickness in the range of approximately 0.5 μm to 40 μm, an electrochemical cell electrode.

[0573] 47. An electrochemical cell electrode, wherein, in any one of the preceding examples, the thickness is configured to substantially prevent any one or more of the formation or growth of Li dendrites.

[0574] 48. In any one of the preceding examples, the porous structure channel is:

[0575] A first part configured to provide a Li ion conduit;

[0576] A second part configured to facilitate rapid Li ion transport; and

[0577] An electrochemical cell electrode further comprising a third part configured to confine the above-mentioned electroactive material.

[0578] 49. An electrochemical cell electrode having an electrical conductivity in the range of about 1,000 S / m to about 20,000 S / m in any one of the prior examples.

[0579] 50. An electrochemical cell electrode comprising, in any one of the prior examples, one or more additional film layers deposited on the film layer, wherein any one or more of these are configured to provide electrical conductivity that is proportionally reduced to that of the film layer immediately preceding with respect to a direction substantially orthogonal to the electrically conductive substrate.

[0580] 51. An electrochemical cell electrode in which, in any one of the prior examples, the solid electrolyte interface (SEI) is formed near the porous structure.

[0581] 52. An electrochemical cell electrode, wherein, in any one of the prior examples, the electrochemical cell further comprises an artificial solid electrolyte interface (ASEI) located near the porous structure.

[0582] 53. An electrochemical cell electrode, wherein in any one of the preceding examples, the ASEI is formed in situ during the formation of the porous structure or is formed ex situ as any one or more of a coating, a film, or a reactant.

[0583] 54. An electrochemical cell electrode, wherein, in any one of the prior examples, the porous structure comprises one or more surfaces functionalized to be lithium-affinity (lithiophilically).

[0584] 55. An electrochemical cell electrode configured such that, in any one of the prior examples, the one or more surfaces functionalized with lithium affinity provide a Li adsorption center.

[0585] 56. In a method for manufacturing an anode, the method comprises:

[0586] A step of nucleating a plurality of carbon particles at a first concentration level;

[0587] A step of forming a first film on a sacrificial substrate based on the first concentration level, - each of the carbon particles is defined by a plurality of aggregates formed of a few-layer graphene (FLG) sheet fused together -;

[0588] A step of defining a porous structure based on the above FLG sheet; and

[0589] A method comprising the step of injecting molten lithium (Li) metal into the porous structure.

[0590] 57. A method comprising, in any one of the preceding examples, further defining a plurality of interconnected porous channels based on the plurality of carbon particles.

[0591] 58. A method comprising, in any one of the prior examples, further comprising the step of forming a second film by nucleating carbon particles at a second concentration level on the first film.

[0592] 59. A method in any one of the prior examples, wherein the first film is configured to provide a first electrical conductivity and the second film is configured to provide a second electrical conductivity different from the first electrical conductivity.

[0593] 60. In any one of the preceding examples, the second electrical conductivity is lower than the first electrical conductivity.

[0594] 61. A method in any one of the prior examples, wherein the first film has an average thickness in the range of approximately 10 μm to approximately 200 μm.

[0595] 62. A method comprising, in any one of the preceding examples, further a step of growing carbon particles on a roll-to-roll processing apparatus.

[0596] 63. In any one of the preceding examples,

[0597] A step of evaporating the molten Li metal onto a metal foil; and

[0598] A method further comprising the step of rolling the molten Li metal into the porous structure on the metal foil.

[0599] 64. A method comprising, in any one of the preceding examples, further comprising the step of preparing an anode to participate in the reversible migration of Li ions with a cathode prepared by any one or more of chemical functionalization or sulfidation.

[0600] 65. A method comprising, in any one of the prior examples, further comprising the step of densifying a plurality of graphene platelets on the porous structure.

[0601] 66. As a manufacturing process for a lithium (Li) ion battery anode, the above process is:

[0602] A step of depositing a first plurality of carbon particles on a substrate;

[0603] The method comprises the step of forming a first film configured to provide a first electrical conductivity based on a first plurality of carbon particles, wherein each of the first plurality of carbon particles is:

[0604] A plurality of 3D assemblies formed of few-layer graphene (FLG) sheets configured to be orthogonally fused together to define a porous structure; and

[0605] A porous array formed in the above porous structure; and

[0606] A process comprising the step of injecting molten Li metal into the porous structure.

[0607] 67. In any one of the preceding examples,

[0608] A step of depositing a second plurality of carbon particles on the first film; and

[0609] A process further comprising the step of forming a second film configured to provide a first electrical conductivity based on the second plurality of carbon particles.

[0610] 68. A process further comprising, in any one of the preceding examples, a step of selecting an injection rate of the molten Li metal based on the viscous resistance of the molten Li metal.

[0611] 69. A process configured such that, in any one of the preceding examples, the molten Li metal reacts with any one or more of the first plurality of carbon particles to produce a carbide.

[0612] 70. In any one of the preceding examples,

[0613] A step of infiltrating the above molten Li metal into the above porous structure in a vapor phase;

[0614] A step of initiating a chemical reaction between any one or more Li ions provided by the molten Li metal and one or more exposed surfaces of the porous structure; and

[0615] A process further comprising the step of forming one or more lithium-affinity surfaces from one or more exposed surfaces.

[0616] 71. A process further comprising, in any one of the preceding examples, the step of coating any one or more of the lithium-affinity surfaces with an active element comprising any one or more of a halogen or a metal oxide.

[0617] 72. In any one of the preceding examples,

[0618] A step of coating any one or more of lithium-affinity surfaces with any one or more elements having surface energy lower than Li; and

[0619] A process further comprising a step of promoting the wetting enhancement of any one or more Li-affinity surfaces with any one or more elements having a surface energy lower than Li.

[0620] 73. In any one of the preceding examples,

[0621] A process further comprising the step of incorporating any one or more of metal-containing compounds, including metal powder or silicon carbide (SiC), into a carbon preform to produce a binder.

[0622] 74. A process comprising, in any one of the preceding examples, that the Li wetting manipulates the interfacial surface tension.

[0623] 75. A process in any one of the preceding examples, wherein the Li wetting comprises one or more chemical reactions at the interface of Li and the exposed surface of the porous structure.

[0624] 76. In any one of the preceding examples, the above Li wetting enhancement is;

[0625] A step of adding a certain amount of dopant at the above interface; and

[0626] A process comprising a step that affects the degree of Li wetting according to the amount of the above dopant.

[0627] 77. In any one of the preceding examples,

[0628] A process further comprising the step of controlling the adsorption of hydroxyl (OH) or hydroxyl (OH) groups on any one or more exposed surfaces of the porous structure.

Claims

Claim 1 An electrode of a battery, comprising: a plurality of carbon aggregates formed by few-layer graphene (FLG) nanoplates that are joined together and deposited as two or more films on an electrically conductive substrate, wherein the first film comprises a first group of the plurality of carbon aggregates having a relatively low carbon concentration and the second film comprises a second group of the plurality of carbon aggregates having a relatively high carbon concentration, and the plurality of carbon aggregates defined by the FLG nanoplates having a porous structure joined orthogonally to each other; and a plurality of pores of the porous structure, wherein at least some of the plurality of pores are configured to finely confine an electroactive material within the electrode. Claim 2 The electrode according to claim 1, wherein the porous structure comprises one or more lithium-affinity functionalized surfaces. Claim 3 The electrode according to claim 2, wherein the one or more surfaces functionalized with lithium affinity comprise a lithium adsorption center. Claim 4 An electrode according to claim 1, wherein the porous structure comprises mesoscale structuring or micron-scale fractal structuring. Claim 5 The electrode of claim 1, wherein the plurality of pores are configured to receive a liquid electrolyte. Claim 6 The electrode according to claim 1, wherein the porous structure comprises a plurality of interconnected channels, each of the interconnected channels comprising: a first portion configured to provide a lithium ion conduit; a second portion configured for lithium ion transport; and a third portion configured to temporarily confine the electroactive material. Claim 7 An electrode according to claim 1, further comprising a solid-electrolyte interface (SEI) formed near the porous structure. Claim 8 The electrode of claim 1, further comprising an artificial solid-electrolyte interface (ASEI) located near the porous structure. Claim 9 In claim 8, the ASEI is an electrode formed in situ during the formation of the porous structure. Claim 10 The electrode of claim 8, wherein the ASEI comprises one or more of a coating, a film, or a reactant. Claim 11 The electrode of claim 1, wherein the porous structure is configured to expand in the presence of a polysulfide (PS) shuttle within one or more parts of the battery. Claim 12 An electrode according to claim 1, wherein the plurality of carbon assemblies comprises a polymer configured to bond at least some of the plurality of carbon assemblies together and define an open porous scaffold. Claim 13 delete Claim 14 delete Claim 15 delete Claim 16 delete Claim 17 delete Claim 18 delete Claim 19 delete Claim 20 delete Claim 21 delete Claim 22 delete Claim 23 delete Claim 24 delete Claim 25 delete Claim 26 delete Claim 27 delete Claim 28 delete Claim 29 delete Claim 30 delete Claim 31 delete Claim 32 delete Claim 33 delete Claim 34 delete Claim 35 delete Claim 36 delete Claim 37 delete Claim 38 delete Claim 39 delete Claim 40 delete Claim 41 delete Claim 42 delete Claim 43 delete Claim 44 delete Claim 45 delete Claim 46 delete Claim 47 delete Claim 48 delete Claim 49 delete Claim 50 delete Claim 51 delete Claim 52 delete Claim 53 delete Claim 54 delete Claim 55 delete Claim 56 delete Claim 57 delete Claim 58 delete Claim 59 delete Claim 60 delete Claim 61 delete Claim 62 delete Claim 63 delete Claim 64 delete Claim 65 delete Claim 66 delete Claim 67 delete Claim 68 delete Claim 69 delete Claim 70 delete Claim 71 delete Claim 72 delete Claim 73 delete Claim 74 delete Claim 75 delete Claim 76 delete Claim 77 delete

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