Porous carbon scaffold material processing

Abstract

Methods and systems for performing double fines removal. A system has a particle size reduction device (mill), a separator, and a fan. The mill is configured to reduce the particle size of a porous carbon scaffold material to produce porous carbon scaffold particles having a desired particle size distribution and carbon fines and separate desired porous carbon scaffold particles sizes from the carbon fines. The fan is configured to entrain the porous carbon scaffold particles from the mill. The separator is configured to receive the entrained porous carbon scaffold particles and further separate the desired porous carbon scaffold particles from remaining carbon fines.

Description

[0001] POROUS CARBON SCAFFOLD MATERIAL PROCESSING

[0002] BACKGROUND

[0003] Control of particle size distribution is an important factor in powder processing. In particular, fine carbon particles in carbon powder processing (i.e., carbon fines) are undesirable in many particles processes, e.g., a chemical vapor infiltration (CV1) process for porous carbon particles.

[0004] The current technology for removing fine carbon particles includes spiral jet mills that are sometimes configured with a collector tip under the mill. The collector tip allows for the coarse product stream to become separated from the mill grinding air and some of the overly fine particles suspended in the grinding air. However, undesirable carbon fines may still remain in the coarse output produced by the spiral jet mill.

[0005] BRIEF SUMMARY

[0006] Various disclosed embodiments include illustrative systems and methods for creating carbon particles and electrochemical modifier infiltrated carbon particles. In certain embodiments the electrochemical modifier comprises at least one Group 14 element (e.g., carbon or silicon).

[0007] In an illustrative embodiment, a system has a mill (e.g., jet mill, ball mill, water jet mill, and other approaches known in the art), a separator, and a fan. The mill is configured to reduce the particle size of a porous carbon scaffold material to produce porous carbon scaffold particles having a desired particle size distribution and carbon fines and separate desired porous carbon scaffold particles sizes from the carbon fines. The fan is configured to entrain the porous carbon scaffold particles from the mill. The separator is configured to receive the entrained porous carbon scaffold particles and further separate the desired porous carbon scaffold particles from remaining carbon fines.

[0008] In another illustrative embodiment, a method includes milling a porous carbon scaffold material to produce porous carbon scaffold particles and carbon fines using a double discharge jet mill, separating the carbon fines from the porous carbon scaffold particles, entraining the porous carbon scaffold particles from the double discharge jet mill to a separator, and separating remaining carbon fines from the entrained porous carbon scaffold particles using the separator.

[0009] In still another illustrative embodiment, a system includes a porous carbon production system configured to produce a porous carbon scaffold material, a double fines removal system, and a chemical vapor infiltration system configured to infiltrate pores of porous carbon scaffold particles with an electrochemical modifier (e.g., silicon). The double fines removal system includes a mill configured to grind the porous carbon scaffold material to produce porous carbon scaffold particles and carbon fines and separate the porous carbon scaffold particles from the carbon fines, a fan configured to entrain the porous carbon scaffold particles from the mill, and a separator configured to further separate the porous carbon scaffold particles from remaining carbon fines.

[0010] BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a block diagram of material processing system formed in accordance with an embodiment of the present invention.

[0012] Figure 2 is a schematic block diagram of double fines removal system formed in accordance with an embodiment of the present invention.

[0013] Figure 3 is a flow diagram of double fines removal process formed in accordance with an embodiment of the present invention.

[0014] DETAILED DESCRIPTION

[0015] In the following description, certain specific details are set forth in order to provide a thorough understanding of various embodiments. However, one skilled in the art will understand that the disclosure may be practiced without these details. In other instances, well-known structures have not been shown or described in detail to avoid unnecessarily obscuring descriptions of the embodiments. Unless the context requires otherwise, throughout the specification and claims which follow, the word "comprise" and variations thereof, such as, "comprises" and "comprising" are to be construed in an open, inclusive sense, that is, as "including, but not limited to." Further, headings provided herein are for convenience only and do not interpret the scope or meaning of the claimed disclosure.

[0016] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Also, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. It should also be noted that the term "or" is generally employed in its sense including "and / or" unless the content clearly dictates otherwise.

[0017] In various embodiments, as shown in Figure 1, a system 20 is shown for producing a carbon material having an electrochemical modifier. The system 20 includes a porous carbon production system 22, a double fines removal system 24, and a chemical vapor infiltration system 26. A. Porous Scaffold Materials

[0018] For the purposes of embodiments of the current disclosure, a porous scaffold may be used, into which one or more electrochemical modifier (e.g., lithium or silicon) is to be impregnated. In this context, the porous scaffold can comprise various materials. In some embodiments the porous scaffold material primarily comprises carbon, for example hard carbon. Other allotropes of carbon are also envisioned in other embodiments, for example, graphite, amorphous carbon, diamond, C60, carbon nanotubes (e.g., single and / or multiwalled), graphene and / or carbon fibers. The introduction of porosity into the carbon material can be achieved by a variety of means. For instance, the porosity in the carbon material can be achieved by modulation of polymer precursors, and / or processing conditions to create said porous carbon material, and described in detail in the subsequent section.

[0019] In other embodiments, the porous scaffold comprises a polymer material. To this end, a wide variety of polymers are envisioned in various embodiments to have utility, including, but not limited to, inorganic polymers, organic polymers, and additional polymers. Examples of organic polymers includes, but are not limited to, sulfur-containing polymers such polysulfides and polysulfones, low density polyethylene (LDPE), high density polyethylene (HDPE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), nylon, nylon 6, nylon 6,6, teflon (Polytetrafluoroethylene), thermoplastic polyurethanes (TPU), polyureas, poly(lactide), poly(glycolide) and combinations thereof, phenolic resins, polyamides, polyaramids, polyethylene terephthalate, polychloroprene, polyacrylonitrile, polyaniline, polyimide, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PDOT:PSS), polymerized polydivinylbenzene,, and others known in the arts. The organic polymer can be synthetic or natural in origin. In some embodiments, the polymer is a polysaccharide, such as sucrose, starch, cellulose, cellobiose, amylose, amylopectin, gum Arabic, lignin, and the like. In some embodiments, the polysaccharide is derived from the caramelization of mono- or oligomeric sugars, such as fructose, glucose, sucrose, maltose, raffinose, and the like.

[0020] In certain embodiments, the porous scaffold polymer material comprises a coordination polymer. Coordination polymers in this context include, but are not limited to, metal organic frameworks (MOFs). Techniques for production of MOFs, as well as exemplary species of MOFs, are known and described in the art ("The Chemistry and Applications of Metal-Organic Frameworks, Hiroyasu Furukawa et al. Science 341, (2013); DOI: 10.1126 / science.1230444). Examples of MOFs in the context include, but are not limited to, Basolite™ materials and zeolitic imidazolate frameworks (ZIFs).

[0021] Concomitant with the myriad variety of polymers envisioned with the potential to provide a porous substrate, various processing approaches are envisioned in various embodiments to achieve said porosity. In this context, general methods for imparting porosity into various materials are myriad, as known in the art, including, but certainly not limited to, methods involving emulsification, micelle creation, gasification, dissolution followed by solvent removal (for example, lyophilization), axial compaction and sintering, gravity sintering, powder rolling and sintering, isostatic compaction and sintering, metal spraying, metal coating and sintering, metal injection molding and sintering, and the like. Other approaches to create a porous polymeric material, including creation of a porous gel, such as a freeze-dried gel, aerogel, and the like are also envisioned.

[0022] In certain embodiments, the porous scaffold material comprises a porous ceramic material. In certain embodiments, the porous scaffold material comprises a porous ceramic foam. In this context, general methods for imparting porosity into ceramic materials are varied, as known in the art, including, but certainly not limited to, creation of porous In this context, general methods and materials suitable for comprising the porous ceramic include, but are not limited to, porous aluminum oxide, porous zirconia toughened alumina, porous partially stabilized zirconia, porous alumina, porous sintered silicon carbide, sintered silicon nitride, porous cordierite, porous zirconium oxide, clay-bound silicon carbide, and the like.

[0023] In certain embodiments, the porous material comprises a porous metal. Suitable metals in this regard include, but are not limited to porous aluminum, porous steel, porous nickel, porous Inconcel, porous Hastelloy, porous titanium, porous copper, porous brass, porous gold, porous silver, porous germanium, and other metals capable of being formed into porous structures, as known in the art. In some embodiments, the porous scaffold material comprises a porous metal foam. The types of metals and methods to manufacture related to the same are known in the art. Such methods include, but are not limited to, casting (including foaming, infiltration, and lost-foam casting), deposition (chemical and physical), gas-eutectic formation, and powder metallurgy techniques (such as powder sintering, compaction in the presence of a foaming agent, and fiber metallurgy techniques).

[0024] B. Porous Carbon Scaffold Materials

[0025] Methods for preparing porous carbon materials from polymer precursors are known in the art. For example, methods for preparation of carbon materials are described in U.S. Patent Nos. 7,723,262, 8,293,818, 8,404,384, 8,654,507, 8,916,296, 9,269,502, 10,590,277, and 10,711,140, the full disclosures of which are hereby incorporated by reference in their entireties for all purposes.

[0026] Accordingly, in one embodiment the present disclosure provides a method for preparing any of the carbon materials or polymer gels described above. The method may be performed by the porous carbon production system 22. The carbon materials may be synthesized through pyrolysis of either a single precursor, for example a saccharide material such as sucrose, fructose, glucose, dextrin, maltodextrin, starch, amylopectin, amylose, lignin, gum Arabic, and other saccharides known in the art, and combinations thereof. Alternatively, the carbon materials may be synthesized through pyrolysis of a complex resin, for instance formed using a sol-gel method using polymer precursors such as phenol, resorcinol, bisphenol A, urea, melamine, and other suitable compounds known in the art, and combinations thereof, in a suitable solvent such as water, ethanol, methanol, and other solvents known in the art, and combinations thereof, with cross-linking agents such as formaldehyde, hexamethylenetetramine, furfural, and other cross-linking agents known in the art, and combinations thereof. The resin may be acid or basic, and may contain a catalyst. The catalyst may be volatile or non-volatile. The pyrolysis temperature and dwell time can vary as known in the art.

[0027] In some embodiments, the methods comprise preparation of a polymer gel by a sol gel process, condensation process or crosslinking process involving monomer precursor(s) and a crosslinking agent, two existing polymers and a crosslinking agent or a single polymer and a crosslinking agent, followed by pyrolysis of the polymer gel. The polymer gel may be dried (e.g., freeze dried) prior to pyrolysis; however drying is not necessarily required.

[0028] The target carbon properties can be derived from a variety of polymer chemistries provided the polymerization reaction produces a resin / polymer with the necessary carbon backbone. Different polymer families include novolacs, resoles, acrylates, styrenes, urethanes, rubbers (neoprenes, styrene-butadienes, etc.), nylons, etc. The preparation of any of these polymer resins can occur via a number of different processes including sol gel, emulsion / suspension, solid state, solution state, melt state, etc. for either polymerization and crosslinking processes.

[0029] In some embodiments the reactant comprises phosphorus. In certain other embodiments, the phosphorus is in the form of phosphoric acid. In certain other embodiments, the phosphorus can be in the form of a salt, wherein the anion of the salt comprises one or more phosphate, phosphite, phosphide, hydrogen phosphate, dihydrogen phosphate, hexafluorophosphate, hypophosphite, polyphosphate, or pyrophosphate ions, or combinations thereof. In certain other embodiments, the phosphorus can be in the form of a salt, wherein the cation of the salt comprises one or more phosphonium ions. The nonphosphate containing anion or cation pair for any of the above embodiments can be chosen for those known and described in the art. In the context, exemplary cations to pair with phosphate-containing anions include, but are not limited to, ammonium, tetraethylammonium, and tetramethylammonium ions. In the context, exemplary anions to pair with phosphate-containing cations include, but are not limited to, carbonate, dicarbonate, and acetate ions.

[0030] In some embodiments, the reactant comprises sulfur. In certain other embodiments, the sulfur is in the form of sulfuric acid. In certain other embodiments, the sulfur can be in the form of a salt, wherein the anion of the salt comprises one or more sulfate, sulfite, bisulfide, bisulfite, hypothiocyanite, sulfonium, S-methylmethionine, thiocarbonate, thiocyanate, thiophosphate, thiosilicate, or trimethylsulfonium, or combinations thereof. In some embodiments, the catalyst comprises a basic volatile catalyst. For example, in one embodiment, the basic volatile catalyst comprises ammonium carbonate, ammonium bicarbonate, ammonium acetate, ammonium hydroxide, or combinations thereof. In a further embodiment, the basic volatile catalyst is ammonium carbonate. In another further embodiment, the basic volatile catalyst is ammonium acetate.

[0031] In still other embodiments, the method comprises admixing an acid. In certain embodiments, the acid is a solid at room temperature and pressure. In some embodiments, the acid is a liquid at room temperature and pressure. In some embodiments, the acid is a liquid at room temperature and pressure that does not provide dissolution of one or more of the other polymer precursors.

[0032] In one embodiment a spherical polydivinylbencene spheres are produced by precipitation polymerization, pyrolyzed, and activated by the methods described herein.

[0033] In one embodiment, a porous carbon can be prepared by pyrolysis of a fluorine containing polymer (e.g., polyvinylidenine fluoride) by heating the material to 600°C under an inerting gas such as nitrogen flowing in a horizontal tube furnace. The material was allowed to cool for 30 minutes and subsequently cooled at room departure prior to removing from the furnace. The resulting carbonized material was attrition milled to less than 25-micron particle size distribution and used to prepare electrodes. The porous carbon prepared by this method is rich in fluorine which facilitates formation of lithium fluoride in the initial stage of electrochemical plating of the lithium metal in a lithium ion battery, thereby increasing the lithiophilicity and reduces detrimental dendrite growth in the battery.

[0034] In certain embodiments, the polymer precursor components are blended together and subsequently held for a time and at a temperature sufficient to achieve polymerization. One or more of the polymer precursor components can have particle size less than about 20 mm in size, for example less than 10 mm, for example less than 7 mm, for example, less than 5 mm, for example less than 2 mm, for example less than 1 mm, for example less than 100 microns, for example less than 10 microns. In some embodiments, the particle size of one or more of the polymer precursor components is reduced during the blending process.

[0035] The blending of one or more polymer precursor components in the absence of solvent can be accomplished by methods described in the art, for example ball milling, jet milling, Fritsch milling, planetary mixing, and other mixing methodologies for mixing or blending solid particles while controlling the process conditions (e.g., temperature). The mixing or blending process can be accomplished before, during, and / or after (or combinations thereof) incubation at the reaction temperature.

[0036] Reaction parameters include aging the blended mixture at a temperature and for a time sufficient for the one or more polymer precursors to react with each other and form a polymer. In this respect, suitable aging temperature ranges from about room temperature to temperatures at or near the melting point of one or more of the polymer precursors. In some embodiments, suitable aging temperature ranges from about room temperature to temperatures at or near the glass transition temperature of one or more of the polymer precursors. For example, in some embodiments the solvent free mixture is aged at temperatures from about 20°C to about 600°C, for example about 20°C to about 500°C, for example about 20°C to about 400°C, for example about 20°C to about 300°C, for example about 20°C to about 200°C. In certain embodiments, the solvent free mixture is aged at temperatures from about 50 to about 250°C.

[0037] The reaction duration is generally sufficient to allow the polymer precursors to react and form a polymer, for example the mixture may be aged anywhere from 1 hour to 48 hours, or more or less depending on the desired result. Typical embodiments include aging for a period of time ranging from about 2 hours to about 48 hours, for example in some embodiments aging comprises about 12 hours and in other embodiments aging comprises about 4-8 hours (e.g., about 6 hours).

[0038] In certain embodiments, an electrochemical modifier is incorporated during the above described polymerization process performed by the chemical vapor infiltration system 26 for example. For example, in some embodiments, an electrochemical modifier in the form of metal particles, metal paste, metal salt, metal oxide or molten metal can be dissolved or suspended into the mixture from which the gel resin is produced

[0039] Exemplary electrochemical modifiers for producing composite materials may fall into one or more than one of the chemical classifications. In some embodiments, the electrochemical modifier is a lithium salt, for example, but not limited to, lithium fluoride, lithium chloride, lithium carbonate, lithium hydroxide, lithium benzoate, lithium bromide, lithium formate, lithium hexafluorophosphate, lithium iodate, lithium iodide, lithium perchlorate, lithium phosphate, lithium sulfate, lithium tetraborate, lithium tetrafluorob orate, and combinations thereof.

[0040] In certain embodiments, the electrochemical modifier comprises a metal, and exemplary species includes, but are not limited to aluminum isopropoxide, manganese acetate, nickel acetate, iron acetate, tin chloride, silicon chloride, and combinations thereof. In certain embodiments, the electrochemical modifier is a phosphate compound, including but not limited to phytic acid, phosphoric acid, ammonium dihydrogen phosphate, and combinations thereof. In certain embodiments, the electrochemical modifier comprises silicon, and exemplary species includes, but are not limited to silicon powders, silicon nanotubes, poly crystalline silicon, nanocrystalline silicon, amorphous silicon, porous silicon, nano sized silicon, nano-featured silicon, nano-sized and nano-featured silicon, silicyne, and black silicon, and combinations thereof.

[0041] Electrochemical modifiers can be combined with a variety of polymer systems through either physical mixing or chemical reactions with latent (or secondary) polymer functionality. Examples of latent polymer functionality include, but are not limited to, epoxide groups, unsaturation (double and triple bonds), acid groups, alcohol groups, amine groups, basic groups. Crosslinking with latent functionality can occur via heteroatoms (e.g. vulcanization with sulfur, acid / base / ring opening reactions with phosphoric acid), reactions with organic acids or bases (described above), coordination to transition metals (including but not limited to Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ag, Au), ring opening or ring closing reactions (rotaxanes, spiro compounds, etc.).

[0042] Electrochemical modifiers can also be added to the polymer system through physical blending. Physical blending can include but is not limited to melt blending of polymers and / or co-polymers, the inclusion of discrete particles, chemical vapor deposition of the electrochemical modifier and co-precipitation of the electrochemical modifier and the main polymer material.

[0043] In some instances, the electrochemical modifier can be added via a metal salt solid, solution, or suspension. The metal salt solid, solution or suspension may comprise acids and / or alcohols to improve solubility of the metal salt. In yet another variation, the polymer gel (either before or after an optional drying step) is contacted with a paste comprising the electrochemical modifier. In yet another variation, the polymer gel (either before or after an optional drying step) is contacted with a metal or metal oxide sol comprising the desired electrochemical modifier.

[0044] In addition to the above exemplified electrochemical modifiers, the composite materials may comprise one or more additional forms (i.e., allotropes) of carbon. In this regard, it has been found that inclusion of different allotropes of carbon such as graphite, amorphous carbon, conductive carbon, carbon black, diamond, C60, carbon nanotubes (e.g., single and / or multi-walled), graphene and / or carbon fibers into the composite materials is effective to optimize the electrochemical properties of the composite materials. The various allotropes of carbon can be incorporated into the carbon materials during any stage of the preparation process described herein. For example, during the solution phase, during the gelation phase, during the curing phase, during the pyrolysis phase, during the milling phase, or after milling. In some embodiments, the second carbon form is incorporated into the composite material by adding the second carbon form before or during polymerization of the polymer gel as described in more detail herein. The polymerized polymer gel containing the second carbon form is then processed according to the general techniques described herein to obtain a carbon material containing a second allotrope of carbon.

[0045] In some embodiments, the polymer precursor is a polyvinilbenzene spheres produced by precipitation polymerization. In other embodiments, the polymer precursor in the low or essentially solvent free reaction mixture is a urea or an amine containing compound. For example, in some embodiments the polymer precursor is urea, melamine, hexamethylenetetramine (HMT) or combination thereof. Other embodiments include polymer precursors selected from isocyanates or other activated carbonyl compounds such as acid halides and the like.

[0046] Some embodiments of the disclosed methods include preparation of low or solvent- free polymer gels (and carbon materials) comprising electrochemical modifiers. Such electrochemical modifiers include, but are not limited to nitrogen, silicon, and sulfur. In other embodiments, the electrochemical modifier comprises fluorine, iron, tin, silicon, nickel, aluminum, zinc, or manganese. The electrochemical modifier can be included in the preparation procedure at any step. For example, in some the electrochemical modifier is admixed with the mixture, the polymer phase or the continuous phase.

[0047] The porous carbon material can be achieved via pyrolysis of a polymer produced from precursor materials as described above. In some embodiments, the porous carbon material comprises an amorphous activated carbon that is produced by pyrolysis, physical or chemical activation, or combination thereof in either a single process step or sequential process steps.

[0048] The temperature and dwell time of pyrolysis can be varied, for example the dwell time can vary from 1 min to 10 min, from 10 min to 30 min, from 30 min to 1 hour, for 1 hour to 2 hours, from 2 hours to 4 hours, from 4 hours to 24 h. The temperature can be varied, for example, the pyrolysis temperature can vary from 200°C to 300°C, from 250°C to 350°C, from 350°C to 450°C, from 450°C to 550°C, from 540°C to 650°C, from 650°C to 750°C, from 750°C to 850°C, from 850°C to 950°C, from 950°C to 1050°C, from 1050°C to 1150°C, from 1150°C to 1250°C. In some embodiments, the pyrolysis temperature varies from 650°C to 1100°C. The pyrolysis can be accomplished in an inert gas, for example nitrogen, or argon.

[0049] In some embodiments, an alternate gas is used to further accomplish carbon activation. In certain embodiments, pyrolysis and activation are combined. Suitable gases for accomplishing carbon activation include, but are not limited to, carbon dioxide, carbon monoxide, water (steam), air, oxygen, and further combinations thereof. The temperature and dwell time of activation can be varied, for example the dwell time can vary from 1 min to 10 min, from 10 min to 30 min, from 30 min to 1 hour, for 1 hour to 2 hours, from 2 hours to 4 hours, from 4 hours to 24 h. The temperature can be varied, for example, the pyrolysis temperature can vary from 200°C to 300°C, from 250°C to 350°C, from 350°C to 450°C, from 450°C to 550°C, from 540°C to 650°C, from 650°C to 750°C, from 750°C to 850°C, from 850°C to 950°C, from 950°C to 1050°C, from 1050°C to 1150°C, from 1150°C to 1250°C. In some embodiments, the temperature for combined pyrolysis and activation varies from 650°C to 1100°C.

[0050] In some embodiments, combined pyrolysis and activation is carried out to prepare the porous carbon scaffold. In such embodiments, the process gas can remain the same during processing, or the composition of process gas may be varied during processing. In some embodiments, the addition of an activation gas such as CO2, steam, or combination thereof, is added to the process gas following sufficient temperature and time to allow for pyrolysis of the solid carbon precursors.

[0051] Suitable gases for accomplishing carbon activation include, but are not limited to, carbon dioxide, carbon monoxide, water (steam), air, oxygen, and further combinations thereof. The temperature and dwell time of activation can be varied, for example the dwell time can vary from 1 min to 10 min, from 10 min to 30 min, from 30 min to 1 hour, for 1 hour to 2 hours, from 2 hours to 4 hours, from 4 hours to 24 h. The temperature can be varied, for example, the pyrolysis temperature can vary from 200°C to 300°C, from 250°C to 350°C, from 350°C to 450°C, from 450°C to 550°C, from 540°C to 650°C, from 650°C to 750°C, from 750°C to 850°C, from 850°C to 950°C, from 950°C to 1050°C, from 1050°C to 1150°C, from 1150°C to 1250°C. In some embodiments, the activation temperature varies from 650°C to 1100°C.

[0052] Either prior to the pyrolysis, and / or after pyrolysis, and / or after activation, the carbon may be subjected to a particle size reduction. The particle size reduction can be accomplished by a variety of techniques known in the art, for example by jet milling in the presence of various gases including air, nitrogen, argon, helium, supercritical steam, and other gases known in the art. Other particle size reduction methods, such as grinding, ball milling, jet milling, water jet milling, and other approaches known in the art are also envisioned.

[0053] The porous carbon scaffold may be in the form of particles. The particle size and particle size distribution can be measured by a variety of techniques known in the art, and can be described based on fractional volume. In this regard, the Dv,50 of the carbon scaffold may be between 10 nm and 10 mm, for example between 100 nm and 1 mm, for example between 1 m and 100 fm, for example between 2 fm and 50 fm, example between 3 fm and 30 fm, example between 4 fm and 20 fm, example between 5 fm and 10 fm. In certain embodiments, the Dv,50 is less than 1 mm, for example less than 100 fm, for example less than 50 fm, for example less than 30 fm, for example less than 20 fm, for example less than 10 fm, for example less than 8 fm, for example less than 5 fm, for example less than 3 fm, for example less than 1 fm. In certain embodiments, the Dv,100 is less than 1 mm, for example less than 100 fm, for example less than 50 fm, for example less than 30 fm, for example less than 20 fm, for example less than 10 fm, for example less than 8 fm, for example less than 5 fm, for example less than 3 fm, for example less than 1 fm. In certain embodiments, the Dv,99 is less than 1 mm, for example less than 100 fm, for example less than 50 fm, for example less than 30 fm, for example less than 20 fm, for example less than 10 fm, for example less than 8 fm, for example less than 5 fm, for example less than 3 fm, for example less than 1 fm. In certain embodiments, the Dv,90 is less than 1 mm, for example less than 100 fm, for example less than 50 fm, for example less than 30 fm, for example less than 20 fm, for example less than 10 fm, for example less than 8 fm, for example less than 5 fm, for example less than 3 fm, for example less than 1 fm. In certain embodiments, the Dv,0 is greater than 10 nm, for example greater than 100 nm, for example greater than 500 nm, for example greater than 1 fm, for example greater than 2 fm, for example greater than 5 fm, for example greater than 10 fm. In certain embodiments, the Dv,l is greater than 10 nm, for example greater than 100 nm, for example greater than 500 nm, for example greater than 1 fm, for example greater than 2 fm, for example greater than 5 fm, for example greater than 10 fm. In certain embodiments, the Dv,10 is greater than 10 nm, for example greater than 100 nm, for example greater than 500 nm, for example greater than 1 fm, for example greater than 2 fm, for example greater than 5 fm, for example greater than 10 fm.

[0054] In some embodiments, the surface area of the porous carbon scaffold can comprise a surface area greater than 400 m2 / g, for example greater than 500 m2 / g, for example greater than 750 m2 / g, for example greater than 1000 m2 / g, for example greater than 1250 m2 / g, for example greater than 1500 m2 / g, for example greater than 1750 m2 / g, for example greater than 2000 m2 / g, for example greater than 2500 m2 / g, for example greater than 3000 m2 / g. In other embodiments, the surface area of the porous carbon scaffold can be less than 500 m2 / g. In some embodiments, the surface area of the porous carbon scaffold is between 200 and 500 m2 / g. In some embodiments, the surface area of the porous carbon scaffold is between 100 and 200 m2 / g. In some embodiments, the surface area of the porous carbon scaffold is between 50 and 100 m2 / g. In some embodiments, the surface area of the porous carbon scaffold is between 10 and 50 m2 / g. In some embodiments, the surface area of the porous carbon scaffold can be less than 10 m2 / g.

[0055] In some embodiments, the pore volume of the porous carbon scaffold is greater than 0.4 cm3 / g, for example greater than 0.5 cm3 / g, for example greater than 0.6 cm3 / g, for example greater than 0.7 cm3 / g, for example greater than 0.8 cm3 / g, for example greater than 0.9 cm3 / g, for example greater than 1.0 cm3 / g, for example greater than 1.1 cm3 / g, for example greater than 1.2 cm3 / g, for example greater than 1.4 cm3 / g, for example greater than 1.6 cm3 / g, for example greater than 1.8 cm3 / g, for example greater than 2.0 cm3 / g. In other embodiments, the pore volume of the porous carbon scaffold is less than 0.5 cm3, for example between 0.1 cm3 / g and 0.5 cm3 / g. In certain other embodiments, the pore volume of the porous carbon scaffold is between 0.01 cm3 / g and 0.1 cm3 / g.

[0056] In some other embodiments, the porous carbon scaffold is an amorphous activated carbon with a pore volume between 0.2 and 2.0 cm3 / g. In certain embodiments, the carbon is an amorphous activated carbon with a pore volume between 0.4 and 1.5 cm3 / g. In certain embodiments, the carbon is an amorphous activated carbon with a pore volume between 0.5 and 1.2 cm3 / g. In certain embodiments, the carbon is an amorphous activated carbon with a pore volume between 0.6 and 1.0 cm3 / g.

[0057] In some other embodiments, the porous carbon scaffold comprises a tap density of less than 1.0 g / cm3, for example less than 0.8 g / cm3, for example less than 0.6 g / cm3, for example less than 0.5 g / cm3, for example less than 0.4 g / cm3, for example less than 0.3 g / cm3, for example less than 0.2 g / cm3, for example less than 0.1 g / cm3.

[0058] The surface functionality of the porous carbon scaffold can vary. One property which can be predictive of surface functionality is the pH of the porous carbon scaffold. The presently disclosed porous carbon scaffolds comprise pH values ranging from less than 1 to about 14, for example less than 5, from 5 to 8 or greater than 8. In some embodiments, the pH of the porous carbon is less than 4, less than 3, less than 2 or even less than 1. In other embodiments, the pH of the porous carbon is between about 5 and 6, between about 6 and 7, between about 7 and 8 or between 8 and 9 or between 9 and 10. In still other embodiments, the pH is high and the pH of the porous carbon ranges is greater than 8, greater than 9, greater than 10, greater than 11, greater than 12, or even greater than 13.

[0059] The pore volume distribution of the porous carbon scaffold can vary. For example, the % micropores can comprise less than 30%, for example less than 20%, for example less than 10%, for example less than 5%, for example less than 4%, for example less than 3%, for example less than 2%, for example less than 1%, for example less than 0.5%, for example less than 0.2%, for example, less than 0.1%. In certain embodiments, there is no detectable micropore volume in the porous carbon scaffold.

[0060] The mesopores comprising the porous carbon scaffold can vary. For example, the % mesopores can comprise less than 30%, for example less than 20%, for example less than 10%, for example less than 5%, for example less than 4%, for example less than 3%, for example less than 2%, for example less than 1%, for example less than 0.5%, for example less than 0.2%, for example, less than 0.1%. In certain embodiments, there is no detectable mesopore volume in the porous carbon scaffold.

[0061] In some embodiments, the pore volume distribution of the porous carbon scaffold comprises more than 50% macropores, for example more than 60% macropores, for example more than 70% macropores, for example more than 80% macropores, for example more than 90% macropores, for example more than 95% macropores, for example more than 98% macropores, for example more than 99% macropores, for example more than 99.5% macropores, for example more than 99.9% macropores.

[0062] In certain preferred embodiments, the pore volume of the porous carbon scaffold comprises a blend of micropores, mesopores, and macropores. Accordingly, in certain embodiments, the porous carbon scaffold comprises 0-20% micropores, 30-70% mesopores, and less than 10% macropores. In certain other embodiments, the porous carbon scaffold comprises 0-20% micropores, 0-20% mesopores, and 70-95% macropores. In certain other embodiments, the porous carbon scaffold comprises 20-50% micropores, 50-80% mesopores, and 0-10% macropores. In certain other embodiments, the porous carbon scaffold comprises 40-60% micropores, 40-60% mesopores, and 0-10% macropores. In certain other embodiments, the porous carbon scaffold comprises 80-95% micropores, 0-10% mesopores, and 0-10% macropores. In certain other embodiments, the porous carbon scaffold comprises 0-10% micropores, 30-50% mesopores, and 50-70% macropores. In certain other embodiments, the porous carbon scaffold comprises 0-10% micropores, 70-80% mesopores, and 0-20% macropores. In certain other embodiments, the porous carbon scaffold comprises 0-20% micropores, 70-95% mesopores, and 0-10% macropores. In certain other embodiments, the porous carbon scaffold comprises 0-10% micropores, 70-95% mesopores, and 0-20% macropores.

[0063] In certain embodiments, the % of pore volume in the porous carbon scaffold representing pores between 100 and 1000 A (10 and 100 nm) comprises greater than 30% of the total pore volume, for example greater than 40% of the total pore volume, for example greater than 50% of the total pore volume, for example greater than 60% of the total pore volume, for example greater than 70% of the total pore volume, for example greater than 80% of the total pore volume, for example greater than 90% of the total pore volume, for example greater than 95% of the total pore volume, for example greater than 98% of the total pore volume, for example greater than 99% of the total pore volume, for example greater than 99.5% of the total pore volume, for example greater than 99.9% of the total pore volume.

[0064] In certain embodiments, the pycnometry density of the porous carbon scaffold ranges from about 1 g / cc to about 3 g / cc, for example from about 1.5 g / cc to about 2.3 g / cc. In other embodiments, the skeletal density ranges from about 1.5 cc / g to about 1.6 cc / g, from about 1.6 cc / g to about 1.7 cc / g, from about 1.7 cc / g to about 1.8 cc / g, from about 1.8 cc / g to about 1.9 cc / g, from about 1.9 cc / g to about 2.0 cc / g, from about 2.0 cc / g to about 2.1 cc / g, from about 2.1 cc / g to about 2.2 cc / g or from about 2.2 cc / g to about 2.3 cc / g, from about 2.3 cc to about 2.4 cc / g, for example from about 2.4 cc / g to about 2.5 cc / g.

[0065] In some embodiments, the carbon scaffold pore volume distribution can be described as the number or volume distribution of pores as determined as known in the art based on gas sorption analysis, for example nitrogen gas sorption analysis. In some embodiments the pore size distribution can be expressed in terms of the pore size at which a certain fraction of the total pore volume resides at or below. For example, the pore size at which 10% of the pores reside at or below can be expressed at DPvlO.

[0066] The DPvlO for the porous carbon scaffold can vary, for example DPvlO can be between 0.01 nm and 100 nm, for example between 0.1 nm and 100 nm, for example between 1 nm and 100 nm, for example between 1 nm and 50 nm, for example between 1 nm and 40 nm, for example between 1 nm and 30 nm, for example between 1 nm and 10 nm, for example between 1 nm and 5 nm.

[0067] The DPv50 for the porous carbon scaffold can vary, for example DPv50 can be between 0.01 nm and 100 nm, for example between 0.1 nm and 100 nm, for example between 1 nm and 100 nm, for example between 1 nm and 50 nm, for example between 1 nm and 40 nm, for example between 1 nm and 30 nm, for example between 1 nm and 10 nm, for example between 1 nm and 5 nm. In other embodiments, the DPv50 is between 2 and 100, for example between 2 and 50, for example between 2 and 30, for example between 2 and 20, for example between 2 and 15, for example between 2 and 10.

[0068] The DPv90 for the porous carbon scaffold can vary, for example DPv90 can be between 0.01 nm and 100 nm, for example between 0.1 nm and 100 nm, for example between 1 nm and 100 nm, for example between 1 nm and 50 nm, for example between 1 nm and 50 nm, for example between 1 nm and 40 nm, for example between 1 nm and 30 nm, for example between 1 nm and 10 nm, for example between 1 nm and 5 nm. In other embodiments, the DPv50 is between 2 nm and 100 nm, for example between 2 nm and 50 nm, for example between 2 nm and 30 nm, for example between 2 nm and 20 nm, for example between 2 nm and 15 nm, for example between 2 nm and 10 nm. In some embodiments, the DPv90 is less than 100 nm, for example less than 50 nm, for example less than 40 nm, for example less than 30 nn, for example less than 20 nm, for example less than 15 nm, for example less than 10 nm. In some embodiments, the carbon scaffold comprises a pore volume with greater than 70% micropores (and DPv90 less than 100 nm, for example DPv90 less than 50 nm, for example DPv90 less than 40 nm, for example DPv90 less than 30 nm, for example DPv90 less than 20 nm, for example DPv90 less than 15 nm, for example DPv90 less than 10 nm, for example DPv90 less than 5 nm, for example DPv90 less than 4 nm, for example DPv90 less than 3 nm. In other embodiments, the carbon scaffold comprises a pore volume with greater than 80% micropores and DPv90 less than 100 nm, for example DPv90 less than 50 nm, for example DPv90 less than 40 nm, for example DPv90 less than 30 nm, for example DPv90 less than 20 nm, for example DPv90 less than 15 nm, for example DPv90 less than 10 nm, for example DPv90 less than 5 nm, for example DPv90 less than 4 nm, for example DPv90 less than 3 nm.

[0069] The DPv99 for the porous carbon scaffold can vary, for example DPv99 can be between 0.01 nm and 1000 nm, for example between 0.1 nm and 1000 nm, for example between 1 nm and 500 nm, for example between 1 nm and 200 nm, for example between 1 nm and 150 nm, for example between 1 nm and 100 nm, for example between 1 nm and 50 nm, for example between 1 nm and 20 nm. In other embodiments, the DPv99 is between 2 nm and 500 nm, for example between 2 nm and 200 nm, for example between 2 nm and 150 nm, for example between 2 nm and 100 nm, for example between 2 nm and 50 nm, for example between 2 nm and 20 nm, for example between 2 nm and 15 nm, for example between 2 nm and 10 nm.

[0070] In certain embodiments, the carbon scaffold is modified prior to impregnation of lithium. For example, in certain embodiments, the surface of the carbon pores is functionalized for the purpose of creating a more lithiophilic surface, i.e., surface that interacts preferentially with lithium or lithium containing precursor materials, wherein said preferential interaction can manifest as preferential diffusion, deposition, adsorption of the like.

[0071] In some embodiments metal oxides are used to functionalize the porous carbon and improve lithiophilicity and thereby improve SEI stability of a lithium metal anode. In this embodiment, a porous carbon scaffold is modified with zinc oxide via a hydrothermal solgel synthesis reaction. Zinc acetate dihydrate is dissolved in water and stirred with micronized porous carbon powder. A strong oxidizing agent such as NaOH is then added dropwise into the reaction solution and allowed to react for up to 2 hours, before being separated by filtration and allowed to dry. In some embodiments the metal oxide may be aluminum oxide, nickel oxide, manganese oxide, cobalt oxide, tin oxide, or titanium oxide.

[0072] In still further embodiments the metal oxide is deposited via atomic layer deposition, physical vapor deposition onto the porous carbon surface and then subsequently converted to a metal oxide via chemical or thermal oxidation reactions. In still further embodiments, the porous carbon may be coated with a polymer containing lithium.

[0073] C. Introduction of Silicon into Scaffold Materials to Create Composite Materials

[0074] Nano-sized silicon is difficult to handle and to process in traditional electrodes. Due to the high surface area and preference to agglomerate, uniform dispersion and coating requires special procedures and / or binder systems. To truly be a drop-in replacement for existing graphite anode materials, the next generation Si — C material needs to be micronsized. In a preferred embodiment, the size distribution for the composite is relatively uniform, with upper and lower bounds within a preferred range, for example, Dv,10 of no less than 5 nm, a Dv,50 between 500 nm and 5 fm, and a Dv,90 no greater than 50 fm. In certain embodiments, the composite particles are comprised of the following size distribution: Dv,10 of no less than 50 nm, a Dv,50 between 1 fm and 10 fm, and a Dv,90 no greater than 30 fm. In certain other embodiments, the composite particles are comprised of the following size distribution: Dv,10 of no less than 100 nm, a Dv,50 between 2 fm and 8 fm, and a Dv,90 no greater than 20 fm. In certain further embodiments, the composite particles are comprised of the following size distribution: Dv,10 of no less than 250 nm, a Dv,50 between 4 fm and 6 fm, and a Dv,90 no greater than 15 fm.

[0075] Unlike existing composite materials which bury silicon into a mass of inactive material, it is understood that to achieve optimal performance, silicon needs room to expand and contract. In certain embodiments high pore volume carbons serve as porous scaffolds in which to embed or deposit silicon, and do so in an engineered fashion, filling pore volume of desired range to create impregnated carbon material of the desired size range. Thus, the scaffold, for example the porous carbon material, plays an important role as a framework and engineered in-situ control for expansion and contraction of the material as well as contributing to the overall electron and ion conduction capability of the composite particle. This scaffold structure allows for the movement of electrons and ions. The primary role of the scaffold is to a framework to affix the silicon to a single location and volume, allowing the silcion to outwardly expand and contract while remaining lodged inside the pores of the carbon scaffold material.

[0076] In certain embodiments, the silicon is introduced into the porous carbon by nanoparticle impregnation by the chemical vapor infiltration system 26 of Figure 1. Accordingly, a nano-sized or nano-sized and nano-featured silicon is first produced. In a preferred embodiment, the nano-sized and nano-featured silicon (individually or collectively “nano silicon”) is produced according to methods described in U.S. Patent No. 10,147,950 “Materials With Extremely Durable Intercalation Of Lithium And Manufacturing Methods Thereof,” and / or U.S. Patent No. 11,611,073 “Composites of Porous Nano- Featured Silicon Materials and Carbon Materials,” the full disclosures of which are hereby incorporated by reference in their entireties for all purposes. The porous carbon can be mixed with the nano silicon, for example in a stirred reactor vessel wherein the carbon particles, for example micro sized porous carbon particles, are co-suspended with nano silicon of the desired particle size. The suspension milieu can be varied as known in the art, for example can be aqueous or non-aqueous. In certain embodiments, the suspension fluid can be multi-component, comprising either miscible or non-miscible co-solvents. Suitable co-solvents for aqueous (water) milieu include, but are not limited to, acetone, ethanol, methanol, and others known in the art. A wide variety of non-water soluble milieu are also known in the art, including, but not limited to, heptane, hexane, cyclohexane, oils, such as mineral oils, vegetable oils, and the like. Without being bound by theory, mixing within the reactor vessel allows for diffusion of the silicon nanoparticles within the porous carbon particle. The resulting nano silicon impregnated carbon particles can then be harvested, for example, by centrifugation, filtration, and subsequent drying, all as known in the art.

[0077] To this end, the porous carbon particles with the desired extent and type of porosity are subject to processing that results in creation of silicon within said porosity. For this processing, the porous carbon particles can be first particle size reduced, for example to provide a Dv,50 between 1 and 1000 microns, for example between 1 and 100 microns, for example between 1 and 50 microns, for example between 1 and 20 microns, for example between 1 and 15 microns, for example between 2 and 12 microns, for example between 5 and 10 microns. The particle size reduction can be carried out as known in the art, and as described elsewhere herein, for instance by jet milling.

[0078] In a preferred embodiment, silicon is created within the pores of the porous carbon by subjecting the porous carbon particles to silane gas at elevated temperature and the presence of a silicon-containing gas, preferably silane, in order to achieve silicon deposition via chemical vapor deposition (CVD). The silane gas can be mixed with other inert gases, for example, nitrogen gas. The temperature and time of processing can be varied, for example the temperature can be between 300 and 400° C, for example between 400 and 500°C., for example between 500 and 600°C., for example between 600 and 700° C, for example between 700 and 800° C, for example between 800 and 900° C. The mixture of gas can comprise between 0.1 and 1% silane and remainder inert gas. Alternatively, the mixture of gas can comprise between 1% and 10% silane and remainder inert gas. Alternatively, the mixture of gas can comprise between 10% and 20% silane and remainder inert gas. Alternatively, the mixture of gas can comprise between 20% and 50% silane and remainder inert gas. Alternatively, the mixture of gas can comprise above 50% silane and remainder inert gas. Alternatively, the gas can essentially be 100% silane gas. The reactor in which the CVD process is carried out is according to various designs as known in the art, for example in a fluid bed reactor, a static bed reactor, an elevator kiln, a rotary kiln, a box kiln, or other suitable reactor type. The reactor materials are suitable for this task, as known in the art. In a preferred embodiment, the porous carbon particles are processed under conditions that provide uniform access to the gas phase, for example a reactor wherein the porous carbon particles are fluidized, or otherwise agitated to provide said uniform gas access.

[0079] In some embodiments, the CVD process is a plasma-enhanced chemical vapor deposition (PECVD) process. This process is known in the art to provide utility for depositing thin films from a gas state (vapor) to a solid state on a substrate. Chemical reactions are involved in the process, which occur after creation of a plasma of the reacting gases. The plasma is generally created by RF (AC) frequency or DC discharge between two electrodes, the space between which is filled with the reacting gases. In certain embodiments, the PECVD process is utilized for porous carbon that is coated on a substrate suitable for the purpose, for example a copper foil substrate. The PECVD can be carried out at various temperatures, for example between 300 and 800° C, for example between 300 and 600° C, for example between 300 and 500° C, for example between 300 and 400° C, for example at 350° C. The power can be varied, for example 25W RF, and the silane gas flow required for processing car be varied, and the processing time can be varied as known in the art.

[0080] The silicon that is impregnated into the porous carbon, regardless of the process, is envisioned to have certain properties that are optimal for utility as an energy storage material. For example, the size and shape of the silicon can be varied accordingly to match, while not being bound by theory, the extent and nature of the pore volume within the porous carbon particle. For example, the silicon can be impregnated, deposited by CVD, or other appropriate process into pores within the porous carbon particle comprising pore sizes between 5 nm and 1000 nm, for example between 10 nm and 500 nm, for example between 10 nm and 200 nm, for example between 10 nm and 100 nm, for example between 33 nm and 150 nm, for example between 20 nm and 100 nm. Other ranges of carbon pores sizes with regards to fractional pore volume, whether micropores, mesopores, or macropores, are also envisioned as described elsewhere within this disclosure.

[0081] The oxygen content in silicon can be less than 50%, for example, less than 30%, for example less than 20%, for example less than 15%, for example, less than 10%, for example, less than 5%, for example, less than 1%, for example less than 0.1%. In certain embodiments, the oxygen content in the silicon is between 1 and 30%. In certain embodiments, the oxygen content in the silicon is between 1 and 20%. In certain embodiments, the oxygen content in the silicon is between 1 and 10%. In certain embodiments, the oxygen content in the porous silicon materials is between 5 and 10%.

[0082] In certain embodiments wherein the silicon contains oxygen, the oxygen is incorporated such that the silicon exists as a mixture of silicon and silicon oxides of the general formula SiOx, where X is a non-integer (real number) can vary continuously from 0.01 to 2. In certain embodiments, the fraction of oxygen present on the surface of the nano-feature porous silicon is higher compared to the interior of the particle.

[0083] In certain embodiments, the silicon comprises crystalline silicon. In certain embodiments, the silicon comprises polycrystalline silicon. In certain embodiments, the silicon comprises micro-polycrystalline silicon. In certain embodiments, the silicon comprises nano-polycrystalline silicon. In certain other embodiments, the silicon comprises amorphous silicon. In certain other embodiments, the silicon comprises both crystalline and non-crystalline silicon.

[0084] In certain embodiments, the carbon scaffold to be impregnated or otherwise embedded with silicon can comprise various carbon allotropes and / or geometries. To this end, the carbon scaffold to be impregnated or otherwise embedded with silicon can comprise graphite, nano graphite, graphene, nano graphene, conductive carbon such as carbon black, carbon nanowires, carbon nanotubes, and the like, and combinations thereof.

[0085] In certain embodiments, the carbon scaffold that is impregnated or otherwise embedded with silicon is removed to yield the templated silicon material with desired size characteristics. The removal of the scaffold carbon can be achieved as known in the art, for example by thermal of chemical activation under conditions wherein the silicon does not undergo undesirable changes in its electrochemical properties. Alternatively, if the scaffold is a porous polymer or other material soluble in a suitable solvent, the scaffold can be removed by dissolution.

[0086] D. Double Fines Removal

[0087] In various embodiments, referring to Figure 2, the double fines removal system 24 performs first and second fines removal. The first fines removal includes a particle size reduction device (such as a mill) 42 configured to reduce the size of the porous carbon material received from the porous carbon production system 22 via a feeder 44. The mill 42 produces porous carbon particles of an acceptable size and particle size distribution. The mill 42 may also produce carbon fines (i.e., carbon dust). In one embodiment, the mill 42 is a double discharge spiral jet mill. A top discharge of the jet mill outputs carbon dust to a dust collector 46. A bottom discharge of the jet mill outputs coarse carbon particles (of the acceptable size) to an eductor (i.e., eductor tee) 48. The eductor 48 includes a port connected to the mill 42, an intake port having a fine, high airflow filter 50 to prevent debris from contaminating the milled carbon. The eductor 48 also includes an exit port that may be directly connected to a separator 54 of a second fines removal component or to the separator 54 or a mill baghouse 56 via a diverter 52. The diverter 52 allows for automatic or manual control of outputting the carbon particles from the mill 42 to go to the separator 54 or directly to the mill baghouse 56.

[0088] In various embodiments, the separator 54 further removes particles within the carbon material outputted by the mill 42 that fail to meet predefined particle size standards. The separator 54 is connected to the mill baghouse 56 so that carbon fines may be collected in the mill baghouse 56 and coarse particles may be collected separately. The separator 54 may be a cyclone separator or comparable device. In various embodiments, a venting device or fan 58 is connected to the eductor 48, the diverter 52, the separator 54, and the mill baghouse 56 for entraining the low fines carbon particles to move from the mill 42 through the eductor 48 to the diverter 52, the separator 54, and / or the mill baghouse 56. The external fan 58 can pull coarse, low fines carbon particles through a cyclone separator 54 to remove fines a second time. The double fines removal system 24 mitigates the differences between the flow of grinding air in the mill 42 and the flow of transport air through the cyclone separator 54 which allows for particle size control in the mill 42 to be fully divorced from particle separation control in the separator 54 as both pieces of equipment (42, 54) rely on air flow rate as a process input.

[0089] In various embodiments, a motor of the fan 58 is interlocked with controls of the mill 42 so that air within the mill 42 and the moving components of the feeder 44 turn off if the fan 58 is off. The external fan 58 pulls 300-700 scfm (standard cubic feet per minute) through the eductor 48 and the cyclone separator 54 to separate coarse and fine particles.

[0090] In various embodiments, a controller 60 sends control signals to the feeder 44, the mill 42, the diverter 52, and / or the separator 54 depending upon status of the fan 58 or input by a user via a user interface device 62.

[0091] Referring to Figure 3, a process 80 performs double fines removal. At a block 82, the process 80 performs milling a porous carbon scaffold material to produce porous carbon scaffold particles and carbon fines. Ata block 84, the process 80 performs a first separation of the carbon fines from the porous carbon scaffold particles. At a block 86, the process 80 performs entraining the porous carbon scaffold particles to a separator or a mill baghouse. At a block 88, the process 80 performs a second separation of remaining carbon fines from the porous carbon scaffold particles.

[0092] EXPRESSED EMBODIMENTS

[0093] Embodiment 1. A system comprising a mill configured to grind porous carbon scaffold material to produce porous carbon scaffold particles and carbon fines and separate the porous carbon scaffold particles from the carbon fines, a fan configured to entrain the porous carbon scaffold particles from the mill, and a separator configured to receive the entrained porous carbon scaffold particles and further separate the porous carbon scaffold particles from remaining carbon fines.

[0094] Embodiment 2. The system of the foregoing Embodiment, wherein the mill includes a spiral jet mill.

[0095] Embodiment 3. The system of Embodiment 1, wherein the separator includes a cyclone separator. Embodiment 4. The system of the foregoing Embodiments further comprising a tee joint comprising an input port coupled to the spiral jet mill, an air intake port, and an exhaust port pneumatically coupled to the cyclone separator and the fan.

[0096] Embodiment 5. The system of the foregoing Embodiments wherein the tee joint is an eductor tee.

[0097] Embodiment 6. The system of the foregoing Embodiments further comprising a diverter coupled between the exhaust port of the tee joint and the cyclone separator.

[0098] Embodiment 7. The system of the foregoing Embodiments further comprising a mill baghouse coupled to the diverter.

[0099] Embodiment 8. The system of the foregoing Embodiments, wherein the mill baghouse is coupled to the separator.

[0100] Embodiment 9. The system of the foregoing Embodiments further comprising a dust collector coupled to the first exit port of the mill.

[0101] Embodiment 10. The system of the foregoing Embodiments further comprising a controller configured to control operation of the jet mill, a jet mill feeder, or the separator based on an operational status of the fan.

[0102] Embodiment 11. A method comprising milling a porous carbon scaffold material to produce porous carbon scaffold particles and carbon fines using a double discharge jet mill, separating the carbon fines from the porous carbon scaffold particles, entraining the porous carbon scaffold particles from the double discharge jet mill to a separator, and separating remaining carbon fines from the entrained porous carbon scaffold particles using the separator.

[0103] Embodiment 12. The foregoing method, wherein milling comprises spiral jet milling.

[0104] Embodiment 13. The foregoing method, wherein separating comprises cyclone separating.

[0105] Embodiment 14. The foregoing method, wherein entraining comprises applying forced air using a fan. Embodiment 15. The foregoing Embodiments, the method further comprising diverting the entrained porous carbon scaffold particles from going to a separator based on the entrained porous carbon scaffold particles meeting at least one predefined requirement.

[0106] Embodiment 16. The method of the foregoing Embodiments wherein the diverting comprises diverting the entrained porous carbon scaffold particles to a bagging device.

[0107] Embodiment 17. The method of the foregoing Embodiments further comprising controlling operation of the jet mill, a jet mill feeder, or the separator based on an operational status of the fan.

[0108] Embodiment 18. A system comprising a porous carbon production system configured to produce a porous carbon scaffold material, a double fines removal system, and a chemical vapor infiltration system configured to infiltrate pores of porous carbon scaffold particles with silicon. The double fines removal system comprising a mill configured to grind the porous carbon scaffold material to produce porous carbon scaffold particles and carbon fines and separate the porous carbon scaffold particles from the carbon fines, a fan configured to entrain the porous carbon scaffold particles from the mill, and a separator configured to further separate the porous carbon scaffold particles from remaining carbon fines.

[0109] Embodiment 19. The system of the foregoing Embodiment wherein the mill includes a spiral jet mill, the separator includes a cyclone separator, and the double fines removal system further includes a tee joint couple to the spiral jet mill having an input port coupled to the spiral jet mill, an air intake port, and an exhaust port pneumatically coupled to the cyclone separator and the fan, a diverter coupled between the exhaust port of the tee joint and the cyclone separator, and a mill baghouse coupled to the diverter.

[0110] Embodiment 20. The system of the foregoing Embodiments wherein the double fines removal system further comprises a controller configured to control operation of the spiral jet mill, a jet mill feeder, or the cyclone separator based on operational status of the fan.

[0111] From the foregoing it will be appreciated that, although specific embodiments of the disclosure have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the disclosure. The various embodiments described above can be combined to provide further embodiments.

[0112] All of the U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and / or listed in the Application Data Sheet, including U.S. patent application Serial No. 63 / 586,508, filed September 29, 2023, are incorporated herein by reference, in their entirety. Aspects of the embodiments can be modified, if necessary to employ concepts of the various patents, applications and publications to provide yet further embodiments.

Claims

CLAIMS1. A system comprising: a mill configured to: grind porous carbon scaffold material to produce porous carbon scaffold particles and carbon fines; and separate the porous carbon scaffold particles from the carbon fines; a fan configured to entrain the porous carbon scaffold particles from the mill; and a separator configured to receive the entrained porous carbon scaffold particles and further separate the porous carbon scaffold particles from remaining carbon fines.

2. The system of Claim 1, wherein the mill includes a spiral jet mill.

3. The system of Claim 2, wherein the separator includes a cyclone separator.

4. The system of Claim 3, further comprising a tee joint comprising: an input port coupled to the spiral jet mill; an air intake port; and an exhaust port pneumatically coupled to the cyclone separator and the fan.

5. The system of Claim 4, wherein the tee joint is an eductor tee.

6. The system of Claim 4, further comprising a diverter coupled between the exhaust port of the tee joint and the cyclone separator.

7. The system of Claim 6, further comprising a mill baghouse coupled to the diverter.

8. The system of Claim 7, wherein the mill baghouse is further coupled to the separator.

9. The system of Claim 1, further comprising a dust collector coupled to the first exit port of the mill.

10. The system of Claim 1, further comprising a controller configured to control operation of the jet mill, a jet mill feeder, or the separator based on an operational status of the fan.

11. A method comprising: milling a porous carbon scaffold material to produce porous carbon scaffold particles and carbon fines using a double discharge jet mill; separating the carbon fines from the porous carbon scaffold particles; entraining the porous carbon scaffold particles from the double discharge jet mill to a separator; and separating remaining carbon fines from the entrained porous carbon scaffold particles using the separator.

12. The method of Claim 11, wherein milling comprises spiral jet milling.

13. The method of Claim 12, wherein separating using the separator comprises cyclone separating.

14. The method of Claim 13, wherein entraining comprises applying forced air using a fan.

15. The method of Claim 14, further comprising diverting the entrained porous carbon scaffold particles from going to a separator based on the entrained porous carbon scaffold particles meeting at least one predefined requirement.

16. The method of Claim 15, wherein diverting comprises diverting the entrained porous carbon scaffold particles to a bagging device.

17. The method of Claim 14, further comprising controlling operation of the jet mill, a jet mill feeder, or the separator based on operational status of the fan.

18. A system comprising: a porous carbon production system configured to produce a porous carbon scaffold material; a double fines removal system comprising: a mill configured to: grind the porous carbon scaffold material to produce porous carbon scaffold particles and carbon fines; and separate the porous carbon scaffold particles from the carbon fines; a fan configured to entrain the porous carbon scaffold particles from the mill; and a separator configured to further separate the porous carbon scaffold particles from remaining carbon fines; anda chemical vapor infiltration system configured to infiltrate pores of the porous carbon scaffold particles with silicon.

19. The system of Claim 18, wherein: the mill includes a spiral jet mill; the separator includes a cyclone separator; and the double fines removal system further comprises: a tee joint couple to the spiral jet mill, the tee joint comprising: an input port coupled to the spiral jet mill; an air intake port; and an exhaust port pneumatically coupled to the cyclone separator and the fan; a diverter coupled between the exhaust port of the tee joint and the cyclone separator; and a mill baghouse coupled to the diverter.

20. The system of Claim 19, the double fines removal system further comprises a controller configured to control operation of the spiral jet mill, a jet mill feeder, or the cyclone separator based on an operational status of the fan.

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