Passivation method for controlling the oxygen content and reactivity of silicon-carbon composite materials

Abstract

Passivated silicon-carbon composite materials and related methods are disclosed that solve the problem of providing amorphous nanosized silicon impregnated within porous carbon. Compared to other inferior materials and methods described in the prior art, the disclosed materials and methods have found superior utility in a variety of applications, including energy storage devices such as lithium-ion batteries.

Description

[Technical Field]

[0001] Embodiments of the present invention generally relate to methods for passivation of silicon-carbon composite materials for controlling the oxygen content and reactivity, and related compositions. The silicon-carbon composite is manufactured by impregnating amorphous nano-sized silicon into the pores of a porous scaffold by chemical vapor impregnation using a silicon-containing gas. Suitable porous scaffolds are not particularly limited, but include porous carbon scaffolds and contain carbon having pore volumes including, for example, micropores (less than 2 nm), mesopores (2 to 50 nm), and / or macropores (greater than 50 nm). Chemical vapor impregnation (CVI) of silicon into the pores of the porous scaffold material is achieved by exposing the porous scaffold to a silicon-containing gas (e.g., silane) at high temperatures.

[0002] Passivation can be achieved by using various oxygen-containing gases that penetrate the surface of silicon impregnated into the carbon pores. Alternatively, passivation can be achieved by using various oxygen-free gases that penetrate the surface of silicon impregnated into the carbon pores. Such passivation is important for improving the performance of silicon-carbon composite materials and minimizing undesirable reactivity (e.g., reactivity between silicon and electrolyte components used in lithium-ion batteries). [Background technology]

[0003] Description of related fields CVI is a process in which a gaseous substrate reacts within a porous scaffold material. This approach can be used to manufacture composite materials (e.g., silicon-carbon composites) by decomposing a silicon-containing gas within a porous carbon scaffold at high temperatures. This approach can be used to manufacture various composite materials, and is of particular interest in silicon-carbon (Si-C) composite materials. Such Si-C composite materials have utility, for example, as energy storage materials (e.g., anode material in lithium-ion batteries (LIBs)). LIBs have the potential to replace devices in many applications used today. For example, today's automotive lead-acid batteries are unsuitable for next-generation all-electric and hybrid electric vehicles because they form irreversible and stable sulfates during discharge. Lithium-ion batteries have the potential to replace lead-based systems used today due to their capacity and other considerations.

[0004] To achieve this objective, there continues to be strong interest in the development of new LIB anode materials, particularly silicon (which has 10 times the weight capacity of conventional graphite). However, silicon exhibits large volume changes during cycling, resulting in electrode degradation and destabilization of the solid electrolyte interface (SEI). The most common improvement approach is to reduce the particle size of silicon, either as individual particles or within a matrix (e.g., D V,50 <150nm, for example D V,50 <100nm, for example D V,50 <50nm, for example, D V,50 <20nm, for example, D V,50 <10nm, for example, D V,50 <5nm, for example D V,50The size is <2nm). To date, nanoscale silicon manufacturing technologies have involved high-temperature reduction of silicon oxide, broad-range particle reduction, multi-step toxic etching, and / or other costly processes. Similarly, common matrix approaches involve expensive materials such as graphene or nanographite and / or require complex processes and coatings.

[0005] Scientific literature has shown that non-graphitizable (hard) carbon is advantageous as a LIB anode material (Liu Y, Xue, JS, Zheng T, Dahn, JR. Carbon 1996, 34:193-200; Wu, YP, Fang, SB, Jiang, YY. 1998, 75:201-206; Buiel E, Dahn JR. Electrochim Acta 1999 45:121-130). The basis for this performance improvement lies in the fact that the disordered nature of the graphene layer intercalates Li ions on both sides of the graphene, theoretically doubling the stoichiometric content of Li ions compared to crystalline graphite. Furthermore, in contrast to graphite, where lithiation proceeds only parallel to the stacked graphene plane, the disordered structure intercalates Li ions isotropically, thereby increasing the material's rated capacity. Despite these desirable electrochemical properties, amorphous carbon has not seen widespread adoption in commercial lithium-ion batteries, mainly due to its low FCE and low bulk density (<1 g / cc). Instead, amorphous carbon is more commonly used as a low-mass additive and coating for other active material components in batteries to improve conductivity and suppress surface reactions.

[0006] In recent years, amorphous carbon has attracted considerable attention as a material for LIB batteries and as a coating for silicon anode materials. Such silicon-carbon core-shell structures not only improve conductivity but also have the ability to mitigate the expansion that occurs when silicon is lithiated, thereby stabilizing cycle stability and minimizing problems related to particle pulverization, separation, and SEI integrity (Jung, Y, Lee K, Oh, S. Electrochim Acta 2007 52:7061-7067; Zuo P, Yin G, Ma Y.. Electrochim Acta 2007 52:4878-4883; Ng SH, Wang J, Wexler D, Chew SY, Liu HK. J Phys Chem C 2007 111:11131-11138). Problems associated with this method include a lack of suitable silicon starting materials for the coating process, and an intrinsic lack of engineering voids within the carbon-coated silicon core-shell composite particles to accommodate the expansion of silicon during lithiation. This inevitably leads to a lack of cycle stability due to the breakdown of the core-shell structure and SEI layer. (Beattie SD, Larcher D, Morcrette M, Simon B, Tarascon, JM. J Electrochem Soc 2008 155:A158-A163). [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] U.S. Patent Application No. 7723262 [Patent Document 2] U.S. Patent Application No. 8293818 [Patent Document 3] U.S. Patent Application No. 8404384 [Patent Document 4] U.S. Patent Application No. 8654507 [Patent Document 5] U.S. Patent Application No. 8916296 [License 6] U.S. Patent Application No. 9269502 [License 7] U.S. Patent Application No. 10590277 [License 8] U.S. Patent and Trademark Office Publication No. 2016 / 745197 [Non-licensed literature]

[0008] [Non-licensed Document 1] Liu Y, Xue, JS, Zheng T, Dahn, JR. Carbon 1996, 34:193-200; [Non-licensed Document 2] Wu, YP, Fang, SB, Jiang, YY. 1998, 75:201-206 [Non-licensed Document 3] Buiel E, Dahn JR. Electrochim Acta 1999 45:121-130 [Non-licensed Document 4] Jung, Y, Lee K, Oh, S. Electrochim Acta 2007 52:7061-7067 [Non-licensed Document 5] Zuo P, Yin G, Ma Y.. Electrochim Acta 2007 52:4878-4883 [Non-licensed Document 6] Ng SH, Wang J, Wexler D, Chew SY, Liu HK. J Phys Chem C 2007 111:11131-11138 [Non-licensed Document 7] Beattie SD, Larcher D, Morcrette M, Simon B, Tarascon, JM. J Electrochem Soc 2008 155:A158-A163 [Non-licensed Document 8] Sun et al., 2016, “Heterogeneous reduction of carbon dioxide by hydride-terminated silicon nanocrystals” Nature Communications, 7:1-9 [Non-Patent Document 9] Cicero et al., 2000, “Photoreactivity of Unsaturated Compounds with Hydrogen-Terminated Silicon (111),” Langmuir 16:5688-5695; [Non-Patent Document 10] Cai et al., 2004, “Direct electrical detection of DNA Hybridization at DNA-modified silicon surfaces”, Biosensors and Bioelectronics 19:1013-1019 (2004) [Overview of the project] [Problems that the invention aims to solve]

[0009] An alternative structure to the core-shell structure is one in which amorphous nano-sized silicon is uniformly distributed within the voids of a porous carbon scaffold. Porous carbon has desirable properties: (i) The porosity of carbon provides void volume to accommodate the expansion of silicon during lithiation, thus reducing the net expansion of composite particles at the electrode level; (ii) The disordered graphene network enhances electrical conductivity to silicon, thus enabling faster charge / discharge rates; and (iii) The nanopore structure functions as a template for the synthesis of silicon, thus defining its size, distribution, and morphology. Give. [Means for solving the problem]

[0010] To achieve this objective, the desired inverse hierarchical structure can be achieved by using CVI. Here, the silicon-containing gas penetrates completely into the nanoporous carbon, where it can be broken down into nanoscale silicon. The CVI approach offers several advantages in terms of silicon structure. One advantage is that the nanoporous carbon provides nucleation sites for silicon growth while defining the maximum particle shape and particle size. Limiting silicon growth within the nanoporous structure reduces susceptibility to cracking or pulverization and reduces contact caused by expansion. Furthermore, this structure encourages the retention of nanoscale silicon in the amorphous phase. This property provides opportunities for high charge / discharge rates, especially in combination with silicon proximity within conductive carbon scaffolds. This system provides a high-speed-responsive diffusion pathway for solid-state lithium, which directly supplies lithium ions to the nanoscale silicon interface. Another advantage of silicon provided by CVI within carbon scaffolds is the removal of undesirable crystalline Li 15 This inhibits the formation of the Si4 layer. Another further advantage is that the CVI process creates voids within the particles.

[0011] Thermogravimetric analysis (TGA) may be used to quantify the proportion of silicon in the introduced silicon-carbon composite. For this purpose, the silicon-composite is heated from 25°C to 1100°C. Although not bound by theory, at this temperature, all carbon burns and all silicon oxidizes to SiO2. Thus, the proportion (%) of silicon in the silicon-carbon composite is given by the following formula: %Si=100×[[M1100×(28 / (28+(16×2)))] / M°] [In the formula, when the silicon-carbon composite is heated in air from approximately 25°C to approximately 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M° is the minimum mass of the silicon-carbon composite between 50°C and 200°C. These masses are determined by thermogravimetric analysis.] It is calculated from.

[0012] Thermogravimetric analysis (TGA) may be used to measure the relative amount of silicon impregnated into the pores of porous carbon. TGA can be used to assess the proportion of silicon present in the pores of porous carbon relative to the total silicon present, i.e., the sum of silicon in the pores and on the particle surface. When a silicon-carbon composite is heated in air, the sample shows a mass increase at approximately 300°C to 500°C, which reflects the initiation of silicon oxidation to SiO2. Subsequently, the sample shows a mass decrease as the carbon burns. Subsequently, the sample shows a mass increase reflecting the resumption of the conversion of silicon to SiO2, which increases towards an asymptotic value of 1100°C until the oxidation of silicon is complete. For the purposes of this analysis, the minimum mass recorded when heating the sample from 800°C to 1100°C is estimated to represent the point at which the combustion of carbon is complete. Any further mass increase beyond this point corresponds to the oxidation of silicon to SiO2, and the total mass at the point of oxidation completion is SiO2. Thus, the ratio of un-oxide silicon after carbon combustion to the total weight of silicon is given by the following formula: Z=1.875×[(M1100-M) / M1100]×100 [In the formula, M1100 is the mass of the sample after oxidation is complete at 1100°C, and M is the minimum mass recorded when heating the sample from 800°C to 1100°C.] It can be determined by this method.

[0013] While not theoretically bound, the temperature at which silicon is oxidized under TGA conditions is related to the length scale of the oxide coating on the silicon due to the diffusion of oxygen atoms through the oxide layer. Thus, silicon present within carbon pores will oxidize at a lower temperature than silicon deposits on the particle surface because the coating on the particle surface is necessarily thinner. In this way, the calculation of Z is used to quantitatively assess the proportion of silicon that has not penetrated into the pores of a porous carbon scaffold.

[0014] Simple summary This specification discloses silicon-carbon composite materials with enhanced electrochemical properties and performance, and related methods (including passivation methods), which address the challenges of providing amorphous nano-sized silicon incorporated within porous carbon. Compared to other inferior materials and methods disclosed in prior art, the materials and methods disclosed herein demonstrate superior utility in various applications, including energy storage devices such as lithium-ion batteries.

[0015] The embodiment provides a novel anode material for lithium-silicon batteries. The material comprises a composite containing group 14 elements such as silicon and carbon, the composite containing silicon in a preferred mode (amorphous, nano-sized, and silicon incorporated within porous carbon), and has novel properties that solve the problem of providing an anode material for lithium-silicon batteries. The silicon-carbon composite is manufactured by chemical vapor impregnation (CVI) in which amorphous nano-sized silicon is impregnated into the pores of a porous scaffold. A suitable porous scaffold is not particularly limited, but includes a porous carbon scaffold and contains carbon having pore volumes including, for example, micropores (less than 2 nm), mesopores (2 to 50 nm), and / or macropores (greater than 50 nm). A suitable precursor for the carbon scaffold is not particularly limited, but includes, for example, sugars and polyols, organic acids, phenolic compounds, crosslinking agents, and amine compounds. A suitable composite material is not particularly limited, but includes, for example, a silicon material. The silicon precursor is not particularly limited, but includes silicon-containing gases, such as silanes, higher silanes (di-, tri-, and / or tetrasilanes, etc.), and / or chlorosilanes (mono-, di-, tri-, and tetrachlorosilanes, etc.), and mixtures thereof. CVI for producing silicon in the pores of a porous scaffold material is achieved by exposing the porous scaffold to a silicon-containing gas (e.g., silane) at high temperatures. The porous carbon scaffold may be particulate porous carbon.

[0016] A significant achievement in this regard is the attainment of a desired form of silicon, namely amorphous nanoscale silicon. Furthermore, another important achievement is the impregnation of silicon into the pores of porous carbon. Such materials, such as silicon-carbon composites, have potential as anode materials for energy storage devices (e.g., lithium-silicon batteries). [Brief explanation of the drawing]

[0017] [Figure 1] The relationship between Z and mean Coulomb efficiency in various silicon-carbon composite materials. [Figure 2] Differential capacitance vs. voltage plot of silicon-carbon composite 3 in the second cycle using half-cells. [Figure 3] Differential capacitance vs. voltage plot of silicon-carbon composite 3 during cycles 2 to 5 using half-cells. [Figure 4] dQ / dV vs V plots for various silicon-carbon composite materials. [Figure 5] An example of calculating φ in silicon-carbon composite 3. [Figure 6] Z vs φ plots for various silicon-carbon composite materials.

[0018] Detailed explanation The following description provides certain details to give a full understanding of the various embodiments. However, those skilled in the art will understand that the invention can be implemented without these details. In other examples, known structures are not shown or described in detail to avoid unnecessarily obscuring the description of the embodiments. Unless otherwise noted, in the following specification and claims, the term “comprise,” and its derivatives, such as “comprises” and “comprising,” are to be interpreted in an open and comprehensive sense, i.e., “including, but not limited to.” Furthermore, the headings described herein are for convenience only and do not constitute an interpretation of the scope or meaning of the claimed invention.

[0019] Throughout this specification, any reference to “one embodiment” or “an embodiment” means that any particular feature, structure, or characteristic described in relation to that embodiment is included in at least one embodiment. Thus, the phrases “in one embodiment” or “in an embodiment” appearing in various places throughout this specification do not necessarily all refer to the same embodiment. Furthermore, certain features, structures, or characteristics can be combined in any suitable way in one or more embodiments. Also, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include multiple references unless otherwise noted. Also, unless otherwise noted, the term “or” is generally used to mean “and / or.” [Modes for carrying out the invention]

[0020] A. Porous scaffold material For the purposes of the embodiments of the present invention, a silicon-impregnated porous scaffold may be used. In this embodiment, the porous scaffold can be made of a variety of materials. In some embodiments, the porous scaffold material mainly includes carbon, such as hard carbon. Other allotropes of carbon, such as graphite, amorphous carbon, diamond, C60, carbon nanotubes (e.g., single-layer and / or multi-layer), graphene, and / or carbon fibers are also envisioned in other embodiments. The introduction of porosity into carbon materials can be achieved by various methods. For example, porosity in carbon materials can be achieved by the modulation of polymer precursors and / or processing conditions when producing the porous carbon material, which will be described in detail in the following sections.

[0021] In other embodiments, the porous scaffold comprises a polymer material. For this purpose, a wide range of useful polymers (but not limited to, inorganic polymers, organic polymers, and addition polymers) are envisioned in various embodiments. The inorganic polymers in this embodiment are not limited to, but include silicon-silicon homochain polymers such as polysilanes, silicon carbides, polygermanes, and polystannanes. Further examples of inorganic polymers include, but are not limited to, heterochain polymers such as polyborazylenes, and polysiloxanes such as polydimethylsiloxane (PDMS), polymethylhydrosiloxane (PMHS), and polydiphenylsiloxane, as well as polysilazanes such as perhydridopolysilazane (PHPS), polyphosphazene, and poly(dichlorophosphazene), and polyphosphates, polythiazyls, and polysulfides. Examples of organic polymers include, but are not limited to, low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), nylon, nylon 6, nylon 6,6, This includes Teflon (polytetrafluoroethylene), thermoplastic polyurethane (TPU), polyurea, polylactic acid, polyglycolides, and combinations thereof, phenolic resins, polyamides, polyaramids, polyethylene terephthalate, polychloroprene, polyacrylonitrile, polyaniline, polyimide, poly(3,4-ethylenedioxythiophene)polystyrene sulfonic acid (PDOT:PSS), and other organic polymers known in the art. The organic polymers may be synthetic or natural. In some embodiments, the polymer is a polysaccharide, including, for example, starch, cellulose, cellobiose, amylose, amylopectin, gum arabic, lignin, etc. In some embodiments, the polysaccharide is derived from the caramelization of monosaccharides or oligosaccharides (e.g., fructose, glucose, sucrose, maltose, and raffinose, etc.).

[0022] In certain embodiments, the porous scaffold polymer material includes a coordination polymer. The coordination polymer in this embodiment is not particularly limited, but includes, for example, metal-organic frameworks (MOFs). The manufacturing techniques for MOFs, as with typical MOF species, are known in the art and are described in the following document (The Chemistry and Applications of Metal-Organic Frameworks, Hiroyasu Furukawa et al. Science 341, (2013); DOI: 0.1126 / science.1230444). The MOFs in this invention are not particularly limited, but include, for example, Basolite® materials and zeolitic imidazolate frameworks (ZIFs).

[0023] With a vast number of polymers that are assumed to have the potential to provide porous substrates, various processing approaches are envisioned in various embodiments to achieve the above-mentioned porosity. In this embodiment, there are countless general methods for imparting porosity to various materials, as are known in the art, and are not particularly limited, but include, for example, emulsification, micelle formation, gasification, solvent removal after dissolution (e.g., freeze-drying), 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 so on. Other approaches for producing porous polymer materials are also envisioned, including, for example, the preparation of porous gels such as freeze-dried gels and aerogels.

[0024] In certain embodiments, the porous scaffold material includes a porous ceramic material. In certain embodiments, the porous scaffold material includes a porous ceramic foam. In this embodiment, there are various, but are not limited, common methods for imparting porosity to a ceramic material, including, for example, the fabrication of porous materials, as is known in the art. In this embodiment, suitable common methods and materials for incorporating porous ceramics include, but are not limited, porous aluminum oxide, porous zirconia-reinforced alumina, porous partially stabilized zirconia, porous alumina, porous sintered silicon carbide, sintered silicon nitride, porous cordierite, porous zirconium oxide, and viscosity-bonded silicon carbide.

[0025] In certain embodiments, the porous scaffold comprises porous silica or other oxygen-containing silicon material. The manufacture of sol gels and silicon gels comprising other porous silica materials is known in the art.

[0026] In certain embodiments, the porous material includes a porous metal. Suitable metals in this regard are not particularly limited, but include, for example, porous aluminum, porous steel, porous nickel, porous Inconcel, porous Hasteloy, porous titanium, porous copper, porous brass, porous gold, porous silver, porous germanium, and other metals known in the art that can form porous structures. In some embodiments, the porous scaffold material includes a porous metal foam. The types of metals and methods of production related to the above are known in the art. Such methods are not particularly limited, but include, for example, casting (including foaming, infiltration, and lost-foam casting), agglomeration (chemical and physical), gas eutectic formation, powder metallurgy techniques (powder sintering, pressurization in the presence of a foaming agent, and fiber metallurgy techniques, etc.).

[0027] B. Porous carbon scaffold Methods for producing porous carbon materials from polymer precursors are known in the art. For example, methods for producing carbon materials are described in U.S. Patent Application No. 7723262, U.S. Patent Application No. 8293818, U.S. Patent Application No. 8404384, U.S. Patent Application No. 8654507, U.S. Patent Application No. 8916296, U.S. Patent Application No. 9269502, U.S. Patent Application No. 10590277, and U.S. Patent Publication No. 2016 / 745197, all of which are incorporated herein by reference for all purposes.

[0028] Accordingly, in one embodiment, the present disclosure provides a method for producing any of the carbon materials or polymer gels described above. The carbon material may be synthesized by the thermal decomposition of any single precursor, for example, a sugar material (sucrose, fructose, glucose, dextrin, maltodextrin, starch, amylopectin, amylose, lignin, gum arabic, and other sugars known in the art, and combinations thereof). Alternatively, the carbon material may be synthesized by the thermal decomposition of a composite resin. The composite resin may be formed, for example, by a sol-gel method using a polymer precursor together with a crosslinking agent in a suitable solvent. The polymer precursor includes, for example, phenol, resorcinol, bisphenol A, urea, melamine, and other suitable compounds known in the art, and combinations thereof. The suitable solvent includes, for example, water, ethanol, methanol, and other solvents known in the art, and combinations thereof. The crosslinking agent includes, for example, formaldehyde, hexamethylenetetramine, furfural, and other crosslinking agents known in the art, as well as combinations thereof. The resin may be acidic or basic, and may contain a catalyst. The catalyst may be volatile or non-volatile. The thermal decomposition temperature and reaction time may vary, as known in the art.

[0029] In some embodiments, the method of the present invention comprises the preparation of a polymer gel by a sol-gel method, a condensation process or a crosslinking process (wherein the process includes a monomer precursor and a crosslinking agent, two polymers and a crosslinking agent in a system, or a single polymer and a crosslinking agent), followed by the thermal decomposition of the polymer gel. The polymer gel may be dried (e.g., freeze-dried) before thermal decomposition; however, drying is not necessarily required.

[0030] When a polymerization reaction produces a resin / polymer with the required carbon backbone, the desired carbon properties can derive from the chemical properties of various polymers. Various polymer species include novolacs, resols, acrylates, styrenes, ureathans, rubbers (neoprene, styrene-butadiene, etc.), and nylon. The preparation of any of the above polymer resins can occur through various processes related to polymerization and crosslinking (e.g., sol-gels, emulsions / suspensions, solids, liquids, melts, etc.).

[0031] In some embodiments, an electrochemical modifier is introduced into the material as a polymer. For example, an organic or carbon-containing polymer (e.g., RF) copolymerizes with the polymer and contains an electrochemical modifier. In one embodiment, the electrochemical modifier-containing polymer contains silicon. In one embodiment, the polymer is tetraethylorthosilane (TEOS). In one embodiment, a TEOS solution is added to the RF solution before or during polymerization. In another embodiment, the polymer is a polysilane having organic side groups. In some examples, these side groups are methyl groups, and in other examples, these side groups are phenyl groups. In some examples, the side chains contain group 14 elements (silicon, germanium, tin, or lead). In other examples, the side chains contain group 13 elements (boron, aluminum, boron, gallium, or indium). In other examples, the side chains contain group 15 elements (nitrogen, phosphorus, or arsenic). In other examples, the side chains contain group 16 elements (oxygen, sulfur, or selenium).

[0032] In other embodiments, the electrochemical modifier includes silole. In some examples, it is phenol-silole or silafluorene. In other examples, it is poly-silole or poly-silafluorene. In some examples, silicon is replaced by germanium (germole or germafluorene), tin (stannole or stannafluorene), nitrogen (carbazole), or phosphorus (phosphole or phosphafluorene). In all examples, the heteroatom-containing material may be a small molecule, oligomer, or polymer. The phosphorus atom may or may not be bonded to oxygen.

[0033] In some embodiments, the reactant contains phosphorus. In other specific embodiments, phosphorus is in the form of phosphoric acid. In other specific embodiments, phosphorus may be in the form of a salt, the salt's anion of which contains one or more phosphoric acid, phosphorous acid, phosphide, hydrogen phosphate, dihydrogen phosphate, hexafluorophosphate, hypophosphorous acid, polyphosphate, or pyrophosphate ions, or a combination thereof. In other specific embodiments, phosphorus may be in the form of a salt, the salt's cation of which contains one or more phosphonium ions. Non-phosphates containing any of the anion or cation pairs of the above embodiments can be selected from those known and described in the art. In this embodiment, typical cations that pair with the phosphoric acid-containing anion are not particularly limited, but include, for example, ammonium, tetraethylammonium, and tetramethylammonium ions. In this embodiment, typical anions that pair with the phosphoric acid-containing cation are not particularly limited, but include, for example, carbonic acid, dicarbonate, and acetate ions.

[0034] In some embodiments, the catalyst includes a volatile base catalyst. For example, in one embodiment, the volatile base catalyst includes ammonium carbonate, ammonium dicarbonate, ammonium acetate, ammonium hydroxide, or a combination thereof. In a further embodiment, the volatile base catalyst is ammonium carbonate. In another further embodiment, the volatile base catalyst is ammonium acetate.

[0035] In further embodiments, the method involves mixing acids. In certain embodiments, the acid is solid at room temperature and room pressure. In some embodiments, the acid is liquid at room temperature and room pressure. In some embodiments, the acid is liquid at room temperature and room pressure and does not dissolve one or more other polymer precursors.

[0036] The acid may be selected from many acids suitable for the polymerization process. For example, in some embodiments, the acid is acetic acid, and in other embodiments, the acid is oxalic acid. In further embodiments, the acid is mixed with a first or second solvent such that the ratio of the acid to the solvent is 99:1, 90:10, 75:25, 50:50, 25:75, 20:80, 10:90, or 1:90. In other embodiments, the acid is acetic acid and the first or second solvent is water. In other embodiments, acidity is imparted by the addition of a solid acid.

[0037] The properties of the final product can be altered by changing the total acid content in the mixture. In some embodiments, the acid is present in an amount of about 1% to about 50% by weight relative to the mixture. In other embodiments, the acid is present in an amount of about 5% to about 25% by weight. In other embodiments, the acid is present in an amount of about 10% to about 20% by weight (e.g., about 10%, about 15%, about 20%).

[0038] In certain embodiments, polymer precursor components are blended together and then held at a temperature and time sufficient for polymerization to complete. One or more polymer precursor components may have a particle size of less than 20 mm (e.g., less than 10 mm, less than 7 mm, less than 5 mm, less than 2 mm, less than 1 mm, less than 100 microns, less than 10 microns). In some embodiments, the particle size of one or more polymer precursor components decreases during the blending process.

[0039] Blending one or more polymer precursor components in a solvent-free environment can be achieved by methods described in the art (e.g., ball milling, jet milling, Fritsch milling, planetary mixing, and other mixing methods relating to mixing or blending solid particles while controlling process conditions (e.g., temperature)). The mixing or blending process can be achieved before, during, and / or after incubation at the reaction temperature (or a combination thereof).

[0040] The reaction parameters include aging the blend mixture at room temperature for a sufficient time for one or more polymer precursors to react with each other and form a polymer. In this regard, a suitable aging temperature is in the range from approximately room temperature to the melting point or near the melting point of one or more polymer precursors. In some embodiments, a suitable aging temperature is in the range from approximately room temperature to the glass transition temperature or near the glass transition temperature of one or more polymer precursors. For example, in some embodiments, the solvent-free mixture is aged at about 20°C to about 600°C (e.g., about 20°C to about 500°C, e.g., about 20°C to about 400°C, e.g., about 20°C to about 300°C, e.g., about 20°C to about 200°C). In certain embodiments, the solvent-free mixture is aged at about 50°C to about 250°C.

[0041] The reaction time is generally sufficient for the polymer precursor to react and produce the polymer, for example, the mixture may be aged for 1 to 48 hours at any given time, or longer or shorter depending on the desired result. Typical embodiments include aging in the range of about 2 to about 48 hours, for example, about 12 hours in some embodiments and about 4 to 8 hours (e.g., 6 hours) in other embodiments.

[0042] In certain embodiments, an electrochemical modifier is introduced during the polymerization process described above. For example, in some embodiments, the electrochemical modifier, which may be in the form of metal particles, metal paste, metal salt, metal oxide, or molten metal, may be dissolved or suspended in the mixture that produces the gel resin.

[0043] Typical electrochemical modifiers in the manufacture of composite materials may fall into one or more chemical classifications. In some embodiments, the electrochemical modifier is a lithium salt, and is not particularly limited, but includes, for example, 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 tetrafluoroborate, and combinations thereof.

[0044] In certain embodiments, the electrochemical modifier includes metals, and typical species are not particularly limited but include, for example, aluminum isoproproxide, manganese acetate, nickel acetate, iron acetate, tin chloride, silicon chloride, and combinations thereof. In certain embodiments, the electrochemical modifier is a phosphoric acid compound, and is not particularly limited but includes, for example, phytic acid, phosphoric acid, ammonium dihydrogen phosphate, and combinations thereof. In certain embodiments, the electrochemical modifier includes silicon, and typical species are not particularly limited but include, for example, silicon powder, silicon nanotubes, polycrystalline silicon, nanocrystalline silicon, amorphous silicon, porous silicon, nano-sized silicon, nano-featured silicon, nano-sized and nano-featured silicon, silicine, and black silicon, and combinations thereof.

[0045] Electrochemical modifiers can be bonded to various polymer systems by either physical mixing or chemical reaction with potential (or secondary) polymer functional groups. Examples of potential polymer functional groups are not particularly limited, but include, for example, epoxides, unsaturated (double or triple bonds), acids, alcohols, amines, and bases. Crosslinking with potential functional groups can occur through reactions of heteroatoms (e.g., vulcanization with sulfur, acid / base / ring-opening reactions with phosphoric acid) with organic acids or bases (as described above), coordination to transition metals (e.g., titanium, chromium, manganese, iron, cobalt, nickel, copper, zinc, zirconium, niobium, molybdenum, silver, gold, etc., but not limited to these), and ring-opening or ring-closing reactions (rotaxanes, spiro compounds, etc.).

[0046] Furthermore, electrochemical modifiers may be added to the polymer system by physical blending. Physical blending is not particularly limited, but may include, for example, melt blending of polymers and / or copolymers, incorporation of discrete particles, chemical vapor deposition of electrochemical modifiers, and coprecipitation of electrochemical modifiers and the main polymer material.

[0047] In some examples, the electrochemical modifier may be added via a solid, solution, or suspension of the metal salt. The metal salt solid, solution, or suspension may contain an acid and / or alcohol to enhance the solubility of the metal salt. In other further variations, the polymer gel (either before or after any drying step) comes into contact with a paste containing the electrochemical modifier. In yet another variation, the polymer gel (either before or after any drying step) comes into contact with a metal or metal oxide containing the desired electrochemical modifier.

[0048] In addition to the electrochemical modifiers exemplified above, the composite material may contain one or more additional forms (i.e., allotropes) of carbon. In this regard, the inclusion of various allotropes of carbon (graphite, amorphous carbon, conductive carbon, carbon black, diamond, C60, carbon nanotubes (e.g., single-layer and / or multi-layer), graphene, and / or carbon fiber, etc.) in the composite material has been found to be effective in optimizing the electrochemical properties of the composite material. Various allotropes of carbon can be introduced into the carbon material at any stage of the manufacturing method described herein (e.g., during the dissolution phase, gelation phase, curing phase, pyrolysis phase, milling phase, or after milling). In some embodiments, the second carbon form is introduced into the composite material by adding the second carbon form during or before polymerization of the polymer gel, as described in more detail herein. The polymerized polymer gel containing the second carbon form is processed according to the general method described herein to obtain a carbon material containing the second allotrope of carbon.

[0049] In preferred embodiments, the carbon is produced from a precursor that requires little or no solvent in the process. The structure of the polymer precursor suitable for use in a reaction mixture with little or essentially no solvent is not particularly limited. However, the polymer precursor may react with other polymer precursors or a second polymer precursor to produce a polymer. The polymer precursors include amine-containing compounds, alcohol-containing compounds, and carbonyl-containing compounds, and in some embodiments, for example, the polymer precursor is selected from alcohols, phenols, polyalcohols, sugars, alkylamines, aromatic amines, aldehydes, ketones, carboxylic acids, esters, ureas, acid halides, and isocyanates.

[0050] In one embodiment using a reaction mixture with little solvent or essentially solvent-free solvent, the method comprises the use of first and second polymer precursors, in some embodiments, one of the first or second polymer precursors is a carbonyl-containing compound and the other is an alcohol-containing compound. In some embodiments, the first polymer precursor is a phenol compound and the second polymer precursor is an aldehyde compound (e.g., formaldehyde). In one embodiment, the phenol compound of the above method is phenol, resorcinol, catechol, hydroquinone, phloroglucinol, or a combination thereof; and the aldehyde compound is formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, benzaldehyde, cinnamaldehyde, or a combination thereof. In a further embodiment, the phenol compound is resorcinol, phenol, or a combination thereof, and the aldehyde compound is formaldehyde. In a further embodiment, the phenol compound is resorcinol and the aldehyde compound is formaldehyde. In some embodiments, the polymer precursors are alcohols and carbonyl compounds (e.g., resorcinol and aldehyde), and they are present in a ratio of approximately 0.5:1.0.

[0051] The polymer precursor materials suitable for reaction mixtures with little solvent or essentially no solvent, as described herein, include (a) alcohols, phenolic compounds, and other mono- or polyhydroxy compounds, and (b) aldehydes, ketones, and combinations thereof. Typical alcohols in this embodiment include linear and branched saturated and unsaturated alcohols. Suitable phenolic compounds include polyhydroxybenzenes, such as dihydroxy or trihydroxybenzene. Typical polyhydroxybenzenes include resorcinol (i.e., 1,3-dihydroxybenzene), catechol, hydroquinone, and phloroglucinol. Another suitable compound is bisphenol (e.g., bisphenol A). Mixtures of two or more polyhydroxybenzenes may also be used. Phenols (monohydroxybenzene) may also be used. Typical polyhydroxy compounds include sugars (e.g., glucose, sucrose, fructose, chitin, and other polyols such as mannitol). Aldehydes in this embodiment include: Straight-chain saturated aldehydes, such as methanal (formaldehyde), ethanal (acetaldehyde), propanal (propionaldehyde), and butanal (butyraldehyde); Linear unsaturated aldehydes, such as ethenone and other ketenes, as well as 2-propenal (acrylaldehyde), 2-butenal (crotonaldehyde), and 3-butenal, etc. Branched chain saturated and unsaturated aldehydes; and Aromatic aldehydes, such as benzaldehyde, salicylaldehyde, and hydrocinnamaldehyde, Includes the following ketones: Linear saturated ketones, such as propanone and 2-butanone; Linear unsaturated ketones, such as propenone, 2-butenone, and 3-butenone (methyl vinyl ketone); Branched-chain saturated and unsaturated ketones; and Aromatic ketones, such as methyl benzyl ketone (phenylacetone) and ethyl benzyl ketone, It includes. The polymer precursor material may be a combination of the precursors described above.

[0052] In some embodiments, the polymer precursor in a reaction mixture containing little solvent, or essentially solvent-free, is an alcohol-containing species, and the other polymer precursors are carbonyl-containing species. The relative amounts of alcohol-containing species (e.g., alcohols, phenolic compounds, and mono- or poly-hydroxy compounds, or combinations thereof) reacting with carbonyl-containing species (e.g., aldehydes, ketones, or combinations thereof) can vary substantially. In some embodiments, the ratio of alcohol-containing species to aldehyde species is selected such that the total moles of reactive alcohol groups in the alcohol-containing species are approximately equal to the total moles of reactive carbonyl groups in the aldehyde species. Similarly, the ratio of alcohol-containing species to ketone species may be selected such that the total moles of reactive alcohol groups in the alcohol-containing species are approximately equal to the total moles of reactive carbonyl groups in the ketone species. The same general 1:1 molar ratio is correctly maintained even when the carbonyl-containing species include combinations of aldehyde and ketone species.

[0053] In other embodiments, the polymer precursor in a reaction mixture containing little solvent or essentially no solvent is a urea or amine-containing compound. For example, in some embodiments, the polymer precursor is urea, melamine, hexamethylenetetramine (HMT), or a combination thereof. Other embodiments include a polymer precursor selected from isocyanates or other activated carbonyl compounds (e.g., acid halides).

[0054] Some embodiments of the disclosed methods involve the production of a small-solvent or solvent-free polymer gel (and carbon material) containing an electrochemical modifier. Such electrochemical modifiers are not particularly limited, but include, for example, nitrogen, silicon, and sulfur. In other embodiments, the electrochemical modifiers include fluorine, iron, tin, silicon, nickel, aluminum, zinc, or manganese. The electrochemical modifier may be incorporated at any step in the production process. For example, in some cases, the electrochemical modifier is mixed with the mixture, the polymer phase, or a subsequent phase.

[0055] Blending of one or more polymer precursor components in the absence of solvents can be achieved by methods described in the Art, such as ball milling, jet milling, Fritsch milling, planetary mixing, and other mixing methods relating to mixing or blending solid particles while controlling process conditions (e.g., temperature). The mixing or blending process can be achieved before, during, and / or after incubation at the reaction temperature (or a combination thereof).

[0056] The reaction parameters include aging the blend mixture at a temperature and time sufficient for one or more polymer precursors to react with each other and form a polymer. In this regard, a suitable aging temperature ranges from approximately room temperature to the melting point of one or more polymer precursors, or a temperature near thereto. In some embodiments, a suitable aging temperature ranges from approximately room temperature to the glass transition temperature of one or more polymer precursors, or a temperature near thereto. For example, in some embodiments, the solvent-free mixture is aged 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 from about 50°C to about 250°C.

[0057] Porous carbon materials can be achieved by the thermal decomposition of polymers produced from the precursor materials described above. In some embodiments, the porous carbon material comprises activated amorphous carbon, which is produced by thermal decomposition, physical or chemical activation, or a combination thereof, in either a single-process or a series of processes.

[0058] The temperature and processing time of the pyrolysis can vary; for example, the processing time can range from 1 to 10 minutes, 10 to 30 minutes, 30 minutes to 1 hour, 1 to 2 hours, 2 to 4 hours, or 4 to 24 hours. The temperature can also vary; for example, the pyrolysis temperature can range from 200°C to 300°C, 250°C to 350°C, 350°C to 450°C, 450°C to 550°C, 540°C to 650°C, 650°C to 750°C, 750°C to 850°C, 850°C to 950°C, 950°C to 1050°C, 1050°C to 1150°C, or 1150°C to 1250°C. In some embodiments, the pyrolysis temperature ranges from 650°C to 1100°C. Pyrolysis can be achieved in an inert gas (e.g., nitrogen or argon).

[0059] In some embodiments, alternative gases are used to achieve further carbon activation. In certain embodiments, pyrolysis and activation occur simultaneously. Suitable gases for achieving carbon activation are not particularly limited but include, for example, carbon dioxide, carbon monoxide, water (water vapor), air, oxygen, and further combinations thereof. The activation temperature and processing time may vary, for example, processing time may range from 1 to 10 minutes, 10 to 30 minutes, 30 minutes to 1 hour, 1 to 2 hours, 2 to 4 hours, or 4 to 24 hours. The temperature can vary; for example, the thermal decomposition temperature can range from 200°C to 300°C, 250°C to 350°C, 350°C to 450°C, 450°C to 550°C, 540°C to 650°C, 650°C to 750°C, 750°C to 850°C, 850°C to 950°C, 950°C to 1050°C, 1050°C to 1150°C, and 1150°C to 1250°C. In some embodiments, the temperatures of simultaneous thermal decomposition and activation vary from 650°C to 1100°C.

[0060] In some embodiments, a porous carbon scaffold was produced by simultaneously performing thermal decomposition and activation. In such embodiments, the process gas may remain the same throughout the process, or its composition may change during the process. In some embodiments, the addition of an activated gas (e.g., CO2, vapor, or a combination thereof) is performed on the process gas after sufficient temperature and time for the solid carbon precursor to be thermally decomposed.

[0061] Suitable gases for achieving carbon activation are not particularly limited, but include, for example, carbon dioxide, carbon monoxide, water (steam), air, oxygen, and further combinations thereof. The activation temperature and processing time may vary, for example, processing time may range from 1 to 10 minutes, 10 to 30 minutes, 30 minutes to 1 hour, 1 to 2 hours, 2 to 4 hours, and 4 to 24 hours. The temperature may also vary, for example, the pyrolysis temperature may range from 200°C to 300°C, 250°C to 350°C, 350°C to 450°C, 450°C to 550°C, 540°C to 650°C, 650°C to 750°C, 750°C to 850°C, 850°C to 950°C, 950°C to 1050°C, 1050°C to 1150°C, and 1150°C to 1250°C. In some embodiments, the activation temperature varies from 650°C to 1100°C.

[0062] The particle size of carbon may be reduced before and / or after thermal decomposition and / or after activation. Particle size reduction can be achieved by various methods known in the art, for example, by jet milling in the presence of various gases, including, for example, air, nitrogen, argon, helium, supercritical vapor, and other gases known in the art. Other methods for reducing particle size include grinding, ball milling, jet milling, waterjet milling, and other approaches known in the art.

[0063] The porous carbon scaffold may be in the form of particles. The particle size and particle size distribution can be measured by various methods known in the art and can be expressed on a volume fraction basis. In this regard, the Dv,50 of the carbon scaffold may be 10 nm to 10 mm, for example 100 nm to 1 mm, for example 1 μm to 100 μm, for example 2 μm to 50 μm, for example 3 μm to 30 μm, for example 4 μm to 20 μm, for example 5 μm to 10 μm. In certain embodiments, the Dv,50 is less than 1 mm, for example less than 100 μm, for example less than 50 μm, for example less than 30 μm, for example less than 20 μm, for example less than 10 μm, for example less than 8 μm, for example less than 5 μm, for example less than 3 μm, for example less than 1 μm. In a particular embodiment, Dv,100 is less than 1 mm, for example less than 100 μm, for example less than 50 μm, for example less than 30 μm, for example less than 20 μm, for example less than 10 μm, for example less than 8 μm, for example less than 5 μm, for example less than 3 μm, for example less than 1 μm. In a particular embodiment, Dv,99 is less than 1 mm, for example less than 100 μm, for example less than 50 μm, for example less than 30 μm, for example less than 20 μm, for example less than 10 μm, for example less than 8 μm, for example less than 5 μm, for example less than 3 μm, for example less than 1 μm. In a particular embodiment, Dv,90 is less than 1 mm, for example less than 100 μm, for example less than 50 μm, for example less than 30 μm, for example less than 20 μm, for example less than 10 μm, for example less than 8 μm, for example less than 5 μm, for example less than 3 μm, for example less than 1 μm. In certain embodiments, Dv,0 is greater than 10 nm, for example, greater than 100 nm, for example, greater than 500 nm, for example, greater than 1 μm, for example, greater than 2 μm, for example, greater than 5 μm, for example, greater than 10 μm. In certain embodiments, Dv,1 is greater than 10 nm, for example, greater than 100 nm, for example, greater than 500 nm, for example, greater than 1 μm, for example, greater than 2 μm, for example, greater than 5 μm, for example, greater than 10 μm. In certain embodiments, Dv,10 is greater than 10 nm, for example, greater than 100 nm, for example, greater than 500 nm, for example, greater than 1 μm, for example, greater than 2 μm, for example, greater than 5 μm, for example, greater than 10 μm.

[0064] In some embodiments, the porous carbon scaffold can include a surface area of more than 400 m 2 / g, for example more than 500 m 2 / g, for example more than 750 m 2 / g, for example more than 1000 m 2 / g, for example more than 1250 m 2 / g, for example more than 1500 m 2 / g, for example more than 1750 m 2 / g, for example more than 2000 m 2 / g, for example more than 2500 m 2 / g, for example more than 3000 m 2 / g. In other embodiments, the surface area of the porous carbon scaffold can be less than 500 m 2 / g. In some embodiments, the surface area of the porous carbon scaffold is from 200 m 2 / g to 500 m 2 / g. In some embodiments, the surface area of the porous carbon scaffold is from 100 m 2 / g to 200 m 2 / g. In some embodiments, the surface area of the porous carbon scaffold is from 50 m 2 / g to 100 m 2 / g. In some embodiments, the surface area of the porous carbon scaffold is from 10 m 2 / g to 50 m 2 / g. In some embodiments, the surface area of the porous carbon scaffold can be less than 10 m 2 / g.

[0065] In some embodiments, the pore volume of the porous carbon scaffold is more than 0.4 cm 3 / g, for example more than 0.5 cm 3 / g, for example more than 0.6 cm 3 / g, for example more than 0.7 cm 3 / g, for example more than 0.8 cm 3 / g, for example more than 0.9 cm 3 / g, for example more than 1.0 cm 3 / g, for example more than 1.1 cm 3 / g or more, for example, 1.2cm 3 / g or more, for example, 1.4cm 3 / g or more, for example, 1.6cm 3 / g or more, for example, 1.8cm 3 / g or more, for example, 2.0cm 3 It is greater than / g. In other embodiments, the pore volume of the porous silicon scaffold is 0.5 cm³. 3 Less than, for example, 0.1 cm 3 / g~0.5cm 3 The value is / g. In certain embodiments, the pore volume of the porous silicon scaffold is 0.01 cm³. 3 / g~0.1cm 3 It is / g.

[0066] In some other embodiments, the porous carbon scaffold is activated amorphous carbon, and its pore volume is 0.2–2.0 cm³. 3 The value is / g. In certain embodiments, the carbon is activated amorphous carbon, and its pore volume is 0.4-1.5 cm³. 3 The value is / g. In certain embodiments, the carbon is activated amorphous carbon, and its pore volume is 0.5-1.2 cm³. 3 The value is / g. In certain embodiments, the carbon is activated amorphous carbon, and its pore volume is 0.6-1.0 cm³. 3 It is / g.

[0067] In some other embodiments, the porous carbon scaffold is 1.0 g / cm³ 3 Includes tap densities of less than 0.8 g / cm³. 3 Less than, for example, 0.6 g / cm³ 3 Less than, for example, 0.5 g / cm³ 3 Less than, for example, 0.4 g / cm³ 3 Less than, for example, 0.3 g / cm³ 3 Less than, for example, 0.2 g / cm³ 3 Less than, for example, 0.1 g / cm³ 3 Includes "less than".

[0068] The surface functionality of porous carbon scaffolds can vary. One property that can predict the surface functionality is the pH of the porous carbon scaffold. The porous carbon scaffolds disclosed herein include pH values ​​in the range of less than 1 to about 14, for example, less than 5, 5 to 8, or greater than 8, etc. In some embodiments, the pH of the porous carbon is less than 4, less than 3, less than 2, or less than 1. In other embodiments, the pH of the porous carbon is about 5 to 6, about 6 to 7, about 7 to 8, 8 to 9, or 9 to 10. In yet other embodiments, the pH of the porous carbon is high, greater than 8, greater than 9, greater than 10, greater than 11, greater than 12, or greater than 13.

[0069] The pore volume distribution of a porous carbon scaffold can vary. For example, the percentage of micropores (%) can include less than 30%, and may include, for example, less than 20%, less than 10%, less than 5%, less than 4%, less than 3%, less than 2%, less than 1%, less than 0.5%, less than 0.2%, less than 0.1%, etc. In certain embodiments, there are no detectable micropore volumes in the porous carbon scaffold.

[0070] The mesopores contained in a porous carbon scaffold can vary. For example, the mesopore percentage can be less than 30%, and may include, for example, less than 20%, less than 10%, less than 5%, less than 4%, less than 3%, less than 2%, less than 1%, less than 0.5%, less than 0.2%, less than 0.1%, etc. In certain embodiments, there are no detectable mesopore volumes in the porous carbon scaffold.

[0071] In some embodiments, the pore volume distribution of the porous carbon scaffold includes 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, and so on.

[0072] In certain preferred embodiments, the pore volume of the porous carbon scaffold includes a blend of micropores, mesopores, and macropores. Thus, in certain embodiments, the porous carbon scaffold contains 0-20% micropores, 30-70% mesopores, and less than 10% macropores. In other specific embodiments, the porous carbon scaffold contains 0-20% micropores, 0-20% mesopores, and 70-95% macropores. In other specific embodiments, the porous carbon scaffold contains 20-50% micropores, 50-80% mesopores, and 0-10% macropores. In other specific embodiments, the porous carbon scaffold contains 40-60% micropores, 40-60% mesopores, and 0-10% macropores. In other specific embodiments, the porous carbon scaffold comprises 80-95% micropores, 0-10% mesopores, and 0-10% macropores. In other specific embodiments, the porous carbon scaffold comprises 0-10% micropores, 30-50% mesopores, and 50-70% macropores. In other specific embodiments, the porous carbon scaffold comprises 0-10% micropores, 70-80% mesopores, and 0-20% macropores. In other specific embodiments, the porous carbon scaffold comprises 0-20% micropores, 70-95% mesopores, and 0-10% macropores. In other specific embodiments, the porous carbon scaffold comprises 0-10% micropores, 70-95% mesopores, and 0-20% macropores.

[0073] In certain embodiments, the percentage of pore volume (%) representing pores of 100-1000A (10-100nm) in the porous carbon scaffold includes more than 30% of the total pore volume, for example more than 40% of the total pore volume, for example more than 50% of the total pore volume, for example more than 60% of the total pore volume, for example more than 70% of the total pore volume, for example more than 80% of the total pore volume, for example more than 90% of the total pore volume, for example more than 95% of the total pore volume, for example more than 98% of the total pore volume, for example more than 99% of the total pore volume, for example more than 99.5% of the total pore volume, for example more than 99.9% of the total pore volume.

[0074] In certain embodiments, the pycnometry density of the porous carbon scaffold is in the range of about 1 g / cc to about 3 g / cc, for example, in the range of about 1.5 g / cc to about 2.3 g / cc. In other embodiments, the scaffold density is in the range of about 1.5 g / cc to about 1.6 g / cc, about 1.6 g / cc to about 1.7 g / cc, about 1.7 g / cc to about 1.8 g / cc, about 1.8 g / cc to about 1.9 g / cc, about 1.9 g / cc to about 2.0 g / cc, about 2.0 g / cc to about 2.1 g / cc, about 2.1 g / cc to about 2.2 g / cc, about 2.2 g / cc to about 2.3 g / cc, about 2.3 g / cc to about 2.4 g / cc, and about 2.4 g / cc to about 2.5 g / cc.

[0075] C. Manufacturing of silicon by chemical vapor impregnation (CVI) Chemical vapor deposition (CVD) is a method in which a substrate provides a solid surface containing the first component of a composite, and a gas thermally decomposes on the solid surface of the first component to provide the second component of the composite. Such a CVD approach can be used, for example, to produce Si-C composite materials in which silicon is coated on the outer surface of silicon particles. Alternatively, chemical vapor infiltration (CVI) is a method in which a substrate provides a porous scaffold containing the first component of a composite, and a gas thermally decomposes within the pores of the porous scaffold material to provide the second component of the composite.

[0076] In one embodiment, silicon is produced within the pores of a porous carbon scaffold by exposing porous carbon particles to a silicon-containing precursor gas at a high temperature and in the presence of a silicon-containing gas, preferably a silane, in order to decompose the silicon-containing gas into silicon. In some embodiments, the silicon-containing gas may include higher silanes (such as di-, tri-, and / or tetrasilanes), chlorosilanes (such as mono-, di-, tri-, and tetrachlorosilanes), or mixtures thereof.

[0077] The silicon-containing precursor gas may be mixed with other inert gases, such as nitrogen, hydrogen, argon, helium, or combinations thereof. The processing temperature and time may vary, for example, the temperature may be 200°C to 900°C, 200°C to 250°C, 250°C to 300°C, 300°C to 350°C, 300°C to 400°C, 350°C to 450°C, 350°C to 400°C, 400°C to 500°C, 500°C to 600°C, 600°C to 700°C, 700°C to 800°C, 800°C to 900°C, 600°C to 1100°C, etc.

[0078] The gas mixture may contain 0.1–1% silane and residual inert gas. Alternatively, the gas mixture may contain 1–10% silane and residual inert gas. Alternatively, the gas mixture may contain 10–20% silane and residual inert gas. Alternatively, the gas mixture may contain 20–50% silane and residual inert gas. Alternatively, the gas mixture may contain more than 50% silane and residual inert gas. Alternatively, the gas may contain essentially 100% silane gas. Suitable inert gases include, but are not limited to, hydrogen, nitrogen, argon, and combinations thereof.

[0079] The atmospheric pressure in the CVI process can vary. In some embodiments, the pressure is atmospheric pressure. In some embodiments, the pressure is lower than atmospheric pressure. In some embodiments, the pressure is higher than atmospheric pressure.

[0080] D. Physicochemical and electrochemical properties of silicon-carbon composites While we do not wish to be constrained by theory, it is conceivable that nano-sized silicon can be achieved by filling porous carbon scaffolds with desired pore volume structures (e.g., silicon-filled pores in the range of 5 nm to 1000 nm, or other ranges of silicon-filled pores disclosed anywhere in this specification). This is achieved along with favorable properties of other components of the composite material, such as low surface area, low pycnometric density, and electrochemical performance when the composite includes the anode of a lithium-ion energy storage device.

[0081] In certain embodiments, the silicon particles embedded in the composite have nanoscale properties. The nanoscale properties may have characteristic length scales of preferably less than 1 μm, preferably less than 300 nm, preferably less than 150 nm, preferably less than 100 nm, preferably less than 50 nm, preferably less than 30 nm, preferably less than 15 nm, preferably less than 10 nm, and preferably less than 5 nm.

[0082] In certain embodiments, the silicon embedded in the composite is spherical in shape. In other specific embodiments, the porous silicon particles are non-spherical, for example, in a rod-like or fibrous structure. In some embodiments, the silicon exists as a layer coating the inside of the pores within the porous carbon scaffold. The depth of this silicon layer can vary, for example, from 5nm to 10nm, 5nm to 20nm, 5nm to 30nm, 5nm to 33nm, 10nm to 30nm, 10nm to 50nm, 10nm to 100nm, 10nm to 150nm, 50nm to 150nm, 100nm to 300nm, 300nm to 1000nm, etc.

[0083] In some embodiments, the silicon embedded within the composite is nanosized and resides within the pores of a porous carbon scaffold. For example, the embedded silicon can be impregnated and deposited into the pores of porous carbon particles by CVI or other suitable method, where the porous carbon particles include particle sizes of 5 to 1000 nm, e.g., 10 to 500 nm, e.g., 10 to 200 nm, e.g., 10 to 100 nm, e.g., 33 to 150 nm, e.g., 20 to 100 nm, etc. Other ranges of carbon particle sizes with respect to fragmentary pore volume are similarly assumed, whether they are micropores, mesopores, or macropores.

[0084] In some embodiments, the pore volume distribution of a carbon scaffold can be described as the number of pores or the pore volume distribution, determined based on gas adsorption analysis (e.g., nitrogen gas adsorption analysis) known in the art. In some embodiments, the pore size distribution can be expressed as the pore size at which a certain percentage of the total pore volume consists of pores of a certain size or smaller. For example, a pore size at which 10% of pores are of a certain size or smaller can be represented as DPv10.

[0085] The DPv10 of a porous carbon scaffold can vary; for example, DPv10 can range from 0.01nm to 100nm, 0.1nm to 100nm, 1nm to 100nm, 1nm to 50nm, 1nm to 40nm, 1nm to 30nm, 1nm to 10nm, 1nm to 5nm, and so on.

[0086] The DPv50 of the porous carbon scaffold can vary, for example, from 0.01nm to 100nm, for example, 0.1nm to 100nm, for example, 1nm to 100nm, for example, 1nm to 50nm, for example, 1nm to 40nm, for example, 1nm to 30nm, for example, 1nm to 10nm, for example, 1nm to 5nm, etc. In other embodiments, the DPv50 is 2nm to 100nm, for example, 2nm to 50nm, for example, 2nm to 30nm, for example, 2nm to 20nm, for example, 2nm to 15nm, for example, 2nm to 10nm.

[0087] The DPv90 of the porous carbon scaffold can vary, for example, DPv90 can range from 0.01nm to 100nm, for example, 0.1nm to 100nm, for example, 1nm to 100nm, for example, 1nm to 50nm, for example, 1nm to 50nm, for example, 1nm to 40nm, for example, 1nm to 30nm, for example, 1nm to 10nm, for example, 1nm to 5nm, etc. In other embodiments, DPv50 is 2nm to 100nm, for example, 2nm to 50nm, for example, 2nm to 30nm, for example, 2nm to 20nm, for example, 2nm to 15nm, for example, 2nm to 10nm.

[0088] In some embodiments, DPv90 is less than 100 nm, for example less than 50 nm, for example less than 40 nm, for example less than 30 nm, for example less than 20 nm, for example less than 15 nm, for example less than 10 nm. In some embodiments, the carbon scaffold contains more than 70% micropores and DPv90 less than 100 nm, for example less than 50 nm, for example less than 40 nm, for example less than 30 nm, for example less than 20 nm, for example less than 15 nm, for example less than 10 nm, for example less than 5 nm, for example less than 4 nm, for example less than 3 nm. In other embodiments, the carbon scaffold includes more than 80% micropores and DPv90s less than 100 nm, for example, DPv90s less than 50 nm, for example, DPv90s less than 40 nm, for example, DPv90s less than 30 nm, for example, DPv90s less than 20 nm, for example, DPv90s less than 15 nm, for example, DPv90s less than 10 nm, for example, DPv90s less than 5 nm, for example, DPv90s less than 4 nm, for example, DPv90s less than 3 nm.

[0089] The DPv99 of the porous carbon scaffold can vary, for example, DPv99 may be 0.01nm to 1000nm, e.g., 0.1nm to 1000nm, e.g., 1nm to 500nm, e.g., 1nm to 200nm, e.g., 1nm to 150nm, e.g., 1nm to 100nm, e.g., 1nm to 50nm, e.g., 1nm to 20nm, etc. In other embodiments, DPv99 is 2nm to 500nm, e.g., 2nm to 200nm, e.g., 2nm to 150nm, e.g., 2nm to 100nm, e.g., 2nm to 50nm, e.g., 2nm to 20nm, e.g., 2nm to 15nm, e.g., 2nm to 10nm.

[0090] Embodiments of composites with highly durable lithium intercalation disclosed herein improve numerous properties of electrical energy storage devices, such as lithium-ion batteries. In some embodiments, the silicon-carbon composites disclosed herein exhibit a Z of less than 10, for example, less than 5, less than 4, less than 3, less than 2, less than 1, less than 0.1, less than 0.01, or less than 0.001. In certain embodiments, Z is 0.

[0091] In certain preferred embodiments, the silicon-carbon composite includes a combination of preferably low Z and one other desired physicochemical and / or electrochemical property, or a combination of several other desired physicochemical and / or electrochemical properties. A description of a specific embodiment relating to the properties (including reversible capacitance) of the silicon-carbon composite is shown in Table 1 below. The surface area can be measured, for example, by nitrogen gas adsorption analysis, as is known in the art. The silicon content can be measured, for example, by TGA, as is known in the art. The characteristic value Z can be measured by TGA in accordance with this disclosure. The first cycle efficiency can be measured, for example, by calculation based on the charge and discharge capacity of the first cycle in a full cell or half cell, as is known in the art. For example, the first cycle efficiency can be measured in a half cell in a voltage window of 5mV to 0.8V, or alternatively, 5mV to 1.5V. The reversible capacitance can be described as the maximum reversible capacitance or maximum capacitance, and can be measured in a half-cell within a voltage window of, for example, 5mV to 0.8V, or alternatively, 5mV to 1.5V, as is known in the art.

[0092] Specific characteristic values ​​in the silicon-carbon composite embodiment [Table 1]

[0093] The silicon-carbon composite may include various combinations of characteristic values ​​as shown in Table 1. For example, the silicon-carbon composite may have Z less than 10, 100m 2 This may include a surface area of ​​less than 10 / g, a first-cycle efficiency of more than 80%, and a reversible capacity of 1300mAh / g or more. For example, silicon-carbon composites may have a Z of less than 10 and 100m 2 This may include a surface area of ​​less than 10 / g, a first-cycle efficiency of more than 80%, and a reversible capacity of 1600mAh / g or more. For example, a silicon-carbon composite may have a Z of less than 10 and 20m 2 This may include a surface area of ​​less than 10 / g, a first-cycle efficiency of more than 85%, and a reversible capacity of 1600mAh / g or more. For example, a silicon-carbon composite may have a Z of less than 10, 10m 2 This may include a surface area of ​​less than 10 / g, a first-cycle efficiency of more than 85%, and a reversible capacity of 1600mAh / g or more. For example, a silicon-carbon composite may have a Z of less than 10, 10m 2 This may include a surface area of ​​less than 10 / g, a first-cycle efficiency of more than 90%, and a reversible capacity of 1600mAh / g or more. For example, silicon-carbon composites may have a Z of less than 10, 10m 2 This may include a surface area of ​​less than mAh / g, a first-cycle efficiency of more than 90%, and a reversible capacity of 1800mAh / g or more.

[0094] The silicon-carbon composite may include combinations of the properties described above, and may further include carbon scaffolds that similarly include the properties described herein. Accordingly, a description of specific embodiments relating to combinations of properties of the silicon-carbon composite is shown in Table 2 below.

[0095] Specific characteristics of a silicon-carbon composite embodiment [Table 2]

[0096] As used herein, the percentages "microporosity," "mesoporosity," and "macroporosity" refer to the proportion of micropores, mesopores, and macropores to the total pore volume, respectively. For example, a carbon scaffold with more than 90% microporosity is a carbon scaffold in which 90% of the total pore volume is formed by micropores.

[0097] According to Table 2, silicon-carbon composites can contain various combinations of physical properties. For example, silicon-carbon composites have an I of 0.7 or less. D / I G , Z less than 10, 100m 2 Surface area less than / g, first cycle efficiency greater than 80%, reversible capacity of 1600mAh / g or more, silicon content of 15% to 85%, and 0.2 to 1.2cm² 3 The total pore volume of the carbon scaffold per gram may include more than 80% micropores, less than 20% mesopores, and less than 10% macropores. For example, a silicon-carbon composite may have an I of 0.7 or less. D / I G , Z less than 10, 20m 2 Surface area less than / g, first cycle efficiency greater than 85%, reversible capacity of 1600mAh / g or more, silicon content of 15% to 85%, and 0.2 to 1.2cm² 3 The total pore volume of the carbon scaffold per gram may include more than 80% micropores, less than 20% mesopores, and less than 10% macropores. For example, a silicon-carbon composite may have an I of 0.7 or less. D / I G , Z less than 10, 10m 2 Surface area less than / g, first cycle efficiency greater than 85%, reversible capacity of 1600mAh / g or more, silicon content of 15-85%, and 0.2-1.2cm² 3The total pore volume of the carbon scaffold per gram may include micropores (over 80%), mesopores (less than 20%), and macropores (less than 10%). For example, a silicon-carbon composite may have an I of 0.7 or less. D / I G , Z less than 10, 10m 2 Surface area less than / g, first cycle efficiency greater than 90%, reversible capacity of 1600mAh / g or more, silicon content of 15% to 85%, and 0.2 to 1.2cm² 3 The total pore volume of the carbon scaffold per gram may include micropores (over 80%), mesopores (less than 20%), and macropores (less than 10%). For example, a silicon-carbon composite may have an I of 0.7 or less. D / I G , Z less than 10, 10m 2 Surface area less than / g, first cycle efficiency greater than 90%, reversible capacity of 1800mAh / g or more, silicon content of 15% to 85%, and 0.2 to 1.2cm² 3 The total pore volume of the carbon scaffold per gram may include more than 80% micropores, less than 20% mesopores, and less than 10% macropores.

[0098] Furthermore, according to Table 2, the silicon-carbon composite may include a carbon scaffold containing more than 80% micropores, 30-60% silicon content, an average Coulomb efficiency of 0.9969 or higher, and a Z value of less than 10. For example, the silicon-carbon composite may include a carbon scaffold containing more than 80% micropores, 30-60% silicon content, an average Coulomb efficiency of 0.9970 or higher, and a Z value of less than 10. For example, the silicon-carbon composite may include a carbon scaffold containing more than 80% micropores, 30-60% silicon content, an average Coulomb efficiency of 0.9975 or higher, and a Z value of less than 10. For example, the silicon-carbon composite may include a carbon scaffold containing more than 80% micropores, 30-60% silicon content, an average Coulomb efficiency of 0.9980 or higher, and a Z value of less than 10. For example, the silicon-carbon composite may include a carbon scaffold containing more than 80% micropores, 30-60% silicon content, an average Coulomb efficiency of 0.9985 or higher, and a Z value of less than 10. For example, the silicon-carbon composite may include a carbon scaffold containing more than 80% micropores, 30-60% silicon content, an average Coulomb efficiency of 0.9990 or higher, and a Z value of less than 10. For example, the silicon-carbon composite may include a carbon scaffold containing more than 80% micropores, 30-60% silicon content, an average Coulomb efficiency of 0.9995 or higher, and a Z value of less than 10. For example, the silicon-carbon composite may include a carbon scaffold containing more than 80% micropores, 30-60% silicon content, an average Coulomb efficiency of 0.9970 or higher, and a Z value of less than 10. For example, the silicon-carbon composite may include a carbon scaffold with more than 80% micropores, a silicon content of 30-60%, an average Coulomb efficiency of 0.9999 or higher, and a Z of less than 10.

[0099] Although not bound by theory, the filling of silicon into the pores of porous carbon traps porosity within the porous carbon scaffold particles, resulting in an inaccessible volume, such as the volume inaccessible to nitrogen gas. Thus, the silicon-carbon composite material may exhibit a pycnometry density of less than 2.1 g / cm 3 and, for example, less than 2.0 g / cm 3 and, for example, less than 1.9 g / cm 3 and, for example, less than 1.8 g / cm 3 and, for example, less than 1.7 g / cm 3 and, for example, less than 1.6 g / cm 3 and, for example, less than 1.4 g / cm 3 and, for example, less than 1.2 g / cm 3 and, for example, less than 1.0 g / cm 3 and so on.

[0100] In some embodiments, the silicon-carbon composite material can exhibit a pycnometry density of 1.7 g / cm 3 to 2.1 g / cm 3 and, for example, 1.7 g / cm 3 to 1.8 g / cm 3 and, for example, ①.8 g / cm 3 to 1.9 g / cm 3 and, for example, 1.9 g / cm 3 to 2.0 g / cm 3 and, for example, 2.0 g / cm 3 to 2.1 g / cm 3 and so on. In some embodiments, the silicon-carbon composite material can exhibit a pycnometry density of 1.8 g / cm 3 to 2.1 g / cm 3 In some embodiments, the silicon-carbon composite material can exhibit a pycnometry density of 1.8 g / cm 3 to 2.0 g / cm 3 In some embodiments, the silicon-carbon composite material can exhibit a pycnometry density of 1.9 g / cm 3 to 2.1 g / cm 3

[0101] Note: There seems to be a formatting issue in the original text where "①.8 g / cm" is likely a typo. I've translated it as "1.8 g / cm" as it's the most likely correction. If this is incorrect, please provide the correct information.The pore volume of the composite material exhibiting highly durable lithium intercalation is 0.01 cm³. 3 / g~0.2cm 3 It can be / g. In certain embodiments, the pore volume of the composite material is 0.01 cm³. 3 / g~0.15cm 3 It may be in the range of / g, for example, 0.01cm 3 / g~0.1cm 3 / g, for example, 0.01cm 3 / g~0.05cm 3 It may indicate / g, etc.

[0102] The particle size distribution of composite materials exhibiting highly durable lithium intercalation is equally important for both power performance and volumetric capacity. With improved packing, volumetric capacity may also increase. In one embodiment, the distribution is either a Gaussian distribution with a sharp single peak, bimodal, or polymodal (more than two identifiable peaks, e.g., trimodal). The particle size characteristics of the composite can be described by D0 (smallest particle in the distribution), Dv50 (average particle size), and Dv100 (maximum size of the largest particle). The optimal combination of particle packing and performance is the following size range combination. Particle size reduction in such embodiments can be achieved, as is known in the art, by jet milling, for example, in the presence of various gases. These gases include air, nitrogen, argon, helium, supercritical vapor, and other gases known in the art.

[0103] In one embodiment, the Dv0 of the composite material may be in the range of 1 nm to 5 μm. In other embodiments, the Dv0 of the composite is in the range of 5 nm to 1 μm, for example, 5 to 500 nm, for example, 5 to 100 nm, for example, 10 to 50 nm. In other embodiments, the Dv0 of the composite is in the range of 500 nm to 2 μm, for example, 750 nm to 1 μm, or 1 to 2 μm. In other embodiments, the Dv0 of the composite is 2 to 5 μm, or greater than 5 μm.

[0104] In one embodiment, the Dv1 of the composite material may be in the range of 1 nm to 5 μm. In other embodiments, the Dv1 of the composite is in the range of 5 nm to 1 μm, for example, 5 to 500 nm, for example, 5 to 100 nm, for example, 10 to 50 nm. In other embodiments, the Dv1 of the composite is in the range of 100 nm to 10 μm, 200 nm to 5 μm, 500 nm to 2 μm, 750 nm to 1 μm, or 1 to 2 μm. In other embodiments, the Dv1 of the composite is 2 to 5 μm, or greater than 5 μm.

[0105] In one embodiment, the Dv10 of the composite material may be in the range of 1 nm to 10 μm. In another embodiment, the Dv10 of the composite is in the range of 5 nm to 1 μm, for example, 5 to 500 nm, for example, 5 to 100 nm, for example, 10 to 50 nm. In another embodiment, the Dv10 of the composite is in the range of 100 nm to 10 μm, 500 nm to 10 μm, 500 nm to 5 μm, 750 nm to 1 μm, or 1 to 2 μm. In another embodiment, the Dv10 of the composite is 2 to 5 μm, or greater than 5 μm.

[0106] In some embodiments, the Dv50 of the composite material is in the range of 5 nm to 20 μm. In other embodiments, the Dv50 of the composite is in the range of 5 nm to 1 μm, for example 5 to 500 nm, for example 5 to 100 nm, for example 10 to 50 nm. In other embodiments, the Dv50 of the composite is in the range of 500 nm to 2 μm, 750 nm to 1 μm, or 1 to 2 μm. In yet further embodiments, the Dv50 of the composite is in the range of 1 to 1000 μm, for example 1 to 100 μm, for example 1 to 10 μm, for example 2 to 20 μm, for example 3 to 15 μm, for example 4 to 8 μm. In certain embodiments, the Dv50 is greater than 20 μm, for example greater than 50 μm, for example greater than 100 μm.

[0107] The span is represented by the following formula:

number

[0108] The surface functionality of composite materials exhibiting highly durable lithium intercalation, as disclosed herein, may be modified to obtain desired electrochemical properties. One property that can predict surface functionality is the pH of the composite material. The composite materials disclosed herein include pH ranges from less than 1 to about 14, for example, less than 5, 5 to 8, or greater than 8. In some embodiments, the pH of the composite material is less than 4, less than 3, less than 2, or less than 1. In other embodiments, the pH of the composite material is about 5 to 6, about 6 to 7, about 7 to 8, 8 to 9, or 9 to 10. In further embodiments, the pH of the composite material is high, with pH greater than 8, greater than 9, greater than 10, greater than 11, greater than 12, or greater than 13.

[0109] Silicon-carbon composite materials can contain varying amounts of carbon, oxygen, hydrogen, and nitrogen, which can be measured by CHNO analysis using gas chromatography. In one embodiment, the carbon content of the composite is greater than 98% by weight or greater than 99.9% by weight, as measured by CHNO analysis. In another embodiment, the carbon content of the silicon-carbon composite is in the range of 10 to 90% by weight, for example, 20 to 80% by weight, for example, 30 to 70% by weight, for example, 40 to 60% by weight, etc.

[0110] In some embodiments, the silicon-carbon composite material has a nitrogen content in the range of 0 to 90%, for example, 0.1 to 1%, 1 to 3%, 1 to 5%, 1 to 10%, 10 to 20%, 20 to 30%, or 30 to 90%.

[0111] In some embodiments, the oxygen content is in the range of 0 to 90%, for example, 0.1 to 1%, 1 to 3%, 1 to 5%, 1 to 10%, 10 to 20%, 20 to 30%, or 30 to 90%.

[0112] Silicon-carbon composite materials may incorporate electrochemical modifiers selected to optimize the electrochemical properties of the unmodified composite. The electrochemical modifiers may be introduced in the pore structure and / or on the surface of the porous carbon scaffold, within embedded silicon, or within the final layer of carbon, or by conductive polymers, coatings, or numerous other methods. For example, in some embodiments, the composite material includes a coating of the electrochemical modifier (e.g., silicon, or Al2O3) on the surface of the carbon material. In some embodiments, the composite material contains more than about 100 ppm of the electrochemical modifier. In certain embodiments, the electrochemical modifier is selected from iron, tin, silicon, nickel, aluminum, and manganese.

[0113] In certain embodiments, the electrochemical modifier comprises an element (e.g., silicon, tin, sulfur) capable of lithiating lithium metal at 3 to 0 V. In other embodiments, the electrochemical modifier comprises a metal oxide (e.g., iron oxide, molybdenum oxide, titanium oxide) capable of lithiating lithium metal at 3 to 0 V. In further embodiments, the electrochemical modifier comprises an element (e.g., aluminum, manganese, nickel, metal phosphate) that does not lithiate lithium metal at 3 to 0 V. In further embodiments, the electrochemical modifier comprises a nonmetallic element (e.g., fluorine, nitrogen, hydrogen). In further embodiments, the electrochemical modifier comprises any of the above electrochemical modifiers, or any combination thereof (e.g., tin-silicon, nickel-titanium oxide).

[0114] The electrochemical modifier may be provided in a number of forms. For example, in some embodiments, the electrochemical modifier comprises a salt. In other embodiments, the electrochemical modifier comprises one or more elements in elemental form, such as iron, tin, silicon, nickel, or manganese. In other embodiments, the electrochemical modifier comprises one or more elements in oxide form, such as iron oxide, tin oxide, silicon oxide, nickel oxide, aluminum oxide, or manganese oxide.

[0115] The electrochemical properties of a composite material can be modified, at least partially, by the amount of electrochemical modifier in the material. Here, the electrochemical modifier is an alloy material such as silicon, tin, indium, aluminum, germanium, or gallium. Accordingly, in some embodiments, the composite material contains 0.10% or more, 0.25% or more, 0.50% or more, 1.0% or more, 5.0% or more, 10% or more, 25% or more, 50% or more, 75% or more, 90% or more, 95% or more, 99% or more, or 99.5% or more of the electrochemical modifier.

[0116] The particle size of the composite material may expand upon lithiation compared to the unlithified state. For example, the expansion coefficient is defined as the ratio of the average particle size of the composite material containing the porous silicon material after lithiation to the average particle size under non-lithified conditions. As described in the Art, the above expansion coefficient is relatively large for known, suboptimal silicon-containing materials, for example, about 4X (corresponding to a 400% volume expansion during lithiation). The inventors have found composite materials containing porous silicon material that can exhibit lower expansion (for example, various values ​​such as 3.5-4.0, 3.0-3.5, 2.5-3.0, 2.0-2.5, 1.5-2.0, and 1.0-1.5).

[0117] In certain embodiments, the composite material is assumed to include a portion of the trapped pore volume, i.e., a void volume inaccessible to nitrogen gas. This void volume can be measured by nitrogen gas adsorption measurements. While not theoretically bound, this trapped pore volume is important because it provides a volume through which silicon can expand during lithiation.

[0118] In certain embodiments, the ratio of the trapped void volume to the silicon volume containing the composite particles is 0.1:1 to 10:1. For example, the ratio of the trapped void volume to the silicon volume containing the composite particles is 1:1 to 5:1, or 5:1 to 10:1. In some embodiments, the ratio of the trapped void volume to the silicon volume containing the composite particles is 2:1 to 5:1, or about 3:1, which can efficiently accommodate the maximum expansion of silicon during lithiation.

[0119] In certain embodiments, the electrochemical performance of the composites disclosed herein is tested in half-cells; otherwise, the performance of composites with highly durable lithium intercalations disclosed herein is tested in full cells (e.g., a full-cell coin cell, a full-cell pouch cell, a prismatic cell, or other battery configurations known in the art). Anode compositions containing composites with highly durable lithium intercalations disclosed herein may further include a variety of types, as known in the art. Further formulation components are not particularly limited but include conductive additives, such as conductive carbon (e.g., Super C45, Super P, and Ketjenblack carbon), conductive polymers, and binders (e.g., styrene-butadiene rubber sodium carboxymethylcellulose (SBR-Na-CMC), polyvinylidene fluoride (PVDF), polyimide (PI), and polyacrylic acid (PAA)), and combinations thereof. In certain embodiments, the binder may include lithium ions as counterions.

[0120] Other types, including electrodes, are known in the art. The weight percentage of the active material in the electrode can vary, for example, 1-5% by weight, 5-15% by weight, 15-25% by weight, 25-35% by weight, 35-45% by weight, 45-55% by weight, 55-65% by weight, 65-75% by weight, 75-85% by weight, 85-95% by weight, etc. In some embodiments, the active material makes up 80-95% of the electrode. In certain embodiments, the amount of the conductive additive in the electrode can vary, for example, 1-5% by weight, 5-15% by weight, 15-25% by weight, 25-35% by weight, etc. In some embodiments, the amount of the conductive additive in the electrode is 5-25% by weight. In certain embodiments, the amount of binder may vary, for example, 1-5% by weight, 5-15% by weight, 15-25% by weight, 25-35% by weight, etc. In certain embodiments, the amount of conductive additive in the electrode is 5-25% by weight.

[0121] The silicon-carbon composite material may be pre-lithified, as is known in the art. In certain embodiments, pre-lithification is achieved electrochemically, for example in half-cells, before assembling the lithified anode containing porous silicon material into a full-cell lithium-ion battery. In certain embodiments, pre-lithification is achieved by doping the cathode with a lithium-containing compound (e.g., a lithium-containing salt). Suitable lithium salts in this embodiment are not particularly limited, but include, for example, dilithium tetrabromonickel(II)ate, dilithium tetrachlorocopper(II)ate, lithium azide, lithium benzoate, lithium bromide, lithium carbonate, lithium chloride, lithium cyclohexane butyrate, lithium fluoride, lithium formate, lithium hexafluoroarsenate(V), lithium hexafluorophosphate, lithium hydroxide, lithium iodate, lithium iodide, lithium metaborate, lithium perchlorate, lithium phosphate, lithium sulfate, lithium tetraborate, lithium tetrachloroaluminate, lithium tetrafluoroborate, lithium thiocyanate, lithium trifluoromethanesulfonate, and combinations thereof.

[0122] Anodes containing silicon-carbon composite materials can be paired with various cathode materials to result in full-cell lithium-ion batteries. Examples of suitable cathode materials are known in the art. Examples of such cathode materials are not particularly limited, but include, for example, LiCoO2 (LCO) and LiNi 0.8 Co 0.15 Al 0.05 O2(NCA), LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 It includes O2(NMC), LiMn2O4 and its variants (LMO), and LiFePO4(LFP).

[0123] In a full-cell lithium-ion battery including an anode further comprising a silicon-carbon composite material, the cathode-anode pair can vary. For example, the cathode-anode capacity ratio can vary from 0.7 to 1.3. In certain embodiments, the cathode-anode capacity ratio can vary from 0.7 to 1.0, for example, from 0.8 to 1.0, for example, from 0.85 to 1.0, for example, from 0.9 to 1.0, for example, from 0.95 to 1.0. In other embodiments, the cathode-anode capacity ratio can vary from 1.0 to 1.3, for example, from 1.0 to 1.2, for example, from 1.0 to 1.15, for example, from 1.0 to 1.1, for example, from 1.0 to 1.05. In further embodiments, the ratio of cathode-to-anode capacitances may vary from 0.8 to 1.2, and may vary from, for example, 0.9 to 1.1, or for example, 0.95 to 1.05.

[0124] In a full-cell lithium-ion battery including an anode further comprising a silicon-carbon composite material, the voltage window during charging and discharging can vary. In this regard, the voltage window can vary depending on the various characteristics of the lithium-ion battery, as is known in the art. For example, as is known in the art, the choice of cathode plays a role in the selected voltage window. Examples of voltage windows are diverse, for example, with respect to the potential for Li / Li+, ranging from 2.0V to 5.0V, and for example, from 2.5V to 4.5V, 2.5V to 4.2V, and so on.

[0125] In a full-cell lithium-ion battery including an anode further comprising a silicon-carbon composite material, the cell conditioning method can vary as is known in the art. For example, conditioning can be achieved by performing one or more charge and discharge cycles at various rates, for example, at a rate slower than the desired cycle rate. As is known in the art, the conditioning process may further include the steps of opening the lithium-ion battery, evacuating all gases generated during the conditioning process, and subsequently resealing the lithium-ion battery.

[0126] In a full-cell lithium-ion battery including an anode further comprising a silicon-carbon composite material, the cycle rate may vary as is known in the art, for example, the rate may be C / 20 to 20C, for example C / 10 to 10C, for example C / 5 to 5C, etc. In a particular embodiment, the cycle rate is C / 10. In a particular embodiment, the cycle rate is C / 5. In a particular embodiment, the cycle rate is C / 2. In a particular embodiment, the cycle rate is 1C. In a particular embodiment, the cycle rate is 1C with a periodic decrease to a slower rate (for example, applying a decrease of C / 10 every 20 cycles). In a particular embodiment, the cycle rate is 2C. In a particular embodiment, the cycle rate is 4C. In a particular embodiment, the cycle rate is 5C. In a particular embodiment, the cycle rate is 10C. In a particular embodiment, the cycle rate is 20C.

[0127] The first-cycle efficiency of the highly durable lithium intercalation composite disclosed herein was measured by comparing the lithium inserted into the anode during the first cycle with the lithium extracted from the anode during the first cycle, prior to the prior lithiation modification. When insertion and extraction are equal, the efficiency is 100%. As is known in the art, the anode material can be tested in a half-cell, where the counter electrode is lithium metal, the electrolyte is 1 M LiPF6 and 1:1 ethylene carbonate:diethyl carbonate (EC:DEC), and a commercially available polypropylene separator is used. In certain embodiments, the electrolyte may include various additives known to improve performance, such as fluoroethylene carbonate (FEC) or other related fluorinated carbonate compounds, or ester cosolvents (e.g., methyl butanoate, vinylene carbonate), and other electrolyte additives known to improve the electrochemical performance of silicon-containing anode materials.

[0128] In certain embodiments, the first cycle efficiency in a half-cell may be measured over a voltage window of 5mV to 0.8V. In another embodiment, the first cycle efficiency in a half-cell may be measured over a voltage window of 5mV to 1.0V. In yet another embodiment, the first cycle efficiency in a half-cell may be measured over a voltage window of 5mV to 1.5V. In yet another embodiment, the first cycle efficiency in a half-cell can be measured over a voltage window of 5mV to 2.0V. In other embodiments, the first cycle efficiency is measured in a full-cell battery and measured over a voltage window such as 2.0V to 4.5V, 2.3V to 4.5V, 2.5V to 4.2V, or 3.0V to 4.2V.

[0129] Coulomb efficiency can be averaged, for example, in half-cell testing, it can be averaged over cycles 7 to 25. In certain embodiments, the average efficiency of a composite with very durable lithium intercalation is greater than 0.9 or greater than 90%. In certain embodiments, the average efficiency is greater than 0.95 or greater than 95%. In other specific embodiments, the average efficiency is 0.99 or higher, for example 0.991 or higher, for example 0.992 or higher, for example 0.993 or higher, for example 0.994 or higher, for example 0.995 or higher, for example 0.996 or higher, for example 0.997 or higher, for example 0.998 or higher, for example 0.999 or higher, for example 0.9991 or higher, for example 0.9992 or higher, for example 0.9993 or higher, for example 0.9994 or higher, for example 0.9995 or higher, for example 0.9996 or higher, for example 0.9997 or higher, for example 0.9998 or higher, for example 0.9999 or higher.

[0130] In further other embodiments, the disclosure herein provides a composite material exhibiting highly durable lithium intercalation, where the composite material, when introduced into the electrodes of a lithium-based energy storage device, has a volumetric capacity 10% or more higher than when introduced into the electrodes of a lithium-based energy storage device including graphite electrodes. In some embodiments, the lithium-based energy storage device is a lithium-ion battery. In other embodiments, the composite material has a volumetric capacity in a lithium-based energy storage device that is 5% or more, 10% or more, or 15% or more higher than a similar electrical energy storage device having graphite electrodes. In further other embodiments, the composite material has a volumetric capacity in a lithium-based energy storage device that is 20% or more, 30% or more, 40% or more, 50% or more, 200% or more, 100% or more, 150% or more, or 200% or more higher than a similar electrical energy storage device having graphite electrodes.

[0131] The composite material may be pre-lithiated as is known in the art. These lithium atoms may or may not be separable from carbon. The number of lithium atoms relative to six carbon atoms is determined by the following formula, which is known to those skilled in the art: #Li=Q×3.6×MM / (C%×F) [Here, Q is the lithium extraction capacity (mAh / g) measured at a voltage of 5mV to 2.0V relative to lithium metal, MM is the molecular mass of 72 or 6 carbon atoms, F is the Faraday constant (96500), and C% is the mass percentage of carbon present in the structure, measured by CHNO or XPS.] It can be calculated by [method].

[0132] Composite materials can be characterized by the ratio of lithium atoms to carbon atoms (Li:C), which may be approximately 0:6 to 2:6. In some embodiments, the Li:C ratios are approximately 0.05:6 and approximately 1.9:6. In other embodiments, lithium is in ionic form and not metallic form, and the maximum Li:C ratio is 2.2:6. In other specific embodiments, the Li:C ratios are approximately 1.2:6 to approximately 2:6, approximately 1.3:6 to approximately 1.9:6, approximately 1.4:6 to approximately 1.9:6, approximately 1.6:6 to approximately 1.8:6, or approximately 1.7:6 to approximately 1.8:6. In other embodiments, the Li:C ratios are greater than 1:6, greater than 1.2:6, greater than 1.4:6, greater than 1.6:6, or greater than 1.8:6. In further other embodiments, the Li:C ratio is about 1.4:6, about 1.5:6, about 1.6:6, about 1.7:6, about 1.8:6, or about 2:6. In certain embodiments, the Li:C ratio is about 1.78:6.

[0133] In other specific embodiments, the composite material includes Li:C ratios in the range of approximately 1:6 to approximately 2.5:6, approximately 1.4:6 to approximately 2.2:6, or approximately 1.4:6 to approximately 2:6. In yet another embodiment, the composite material does not necessarily have to contain lithium, but instead has lithium uptake capacity, i.e., the ability to absorb a certain amount of lithium during the material's cycle between, for example, two voltage conditions (for a lithium-ion half-cell, a typical voltage window is 0 to 3V, e.g., 0.005 to 2.7V, e.g., 0.005 to 1V, e.g., 0.005 to 0.8V). While we do not wish to be bound by theory, the lithium uptake capacity of the composite material contributes to superior performance in lithium-based energy storage devices. Lithium uptake capacity is expressed as the ratio of lithium atoms replaced by the composite. In other specific embodiments, composite materials exhibiting highly durable lithium intercalation include lithium uptake capacities ranging from about 1:6 to about 2.5:6, about 1.4:6 to about 2.2:6, or about 1.4:6 to about 2:6, etc.

[0134] In other specific embodiments, the lithium uptake capacity ranges from approximately 1.2:6 to approximately 2:6, approximately 1.3:6 to approximately 1.9:6, approximately 1.4:6 to approximately 1.9:6, approximately 1.6:6 to approximately 1.8:6, or approximately 1.7:6 to approximately 1.8:6. In other embodiments, the lithium uptake capacity is greater than 1:6, greater than 1.2:6, greater than 1.4:6, greater than 1.6:6, or greater than 1.8:6. In yet another embodiment, the Li:C ratio is approximately 1.4:6, approximately 1.5:6, approximately 1.6:6, approximately 1.6:6, approximately 1.7:6, approximately 1.8:6, or approximately 2:6. In one particular embodiment, the Li:C ratio is approximately 1.78:6.

[0135] E. Passivation method for controlling oxygen content and reactivity of silicon-carbon materials using silane as a silicon precursor Low-temperature chemical vapor deposition (CVM), which uses silane gas to obtain silicon elements, produces amorphous structures that are prone to rapid oxidation (spontaneous combustion) if not properly passivated. Current techniques for passivating silicon immediately after synthesis simply require introducing air while it is still in the furnace, allowing the reaction to proceed without flammability concerns. The challenge is that the degree of oxidation can vary dramatically depending on the final surface area of ​​the composite. For example, composites with a high surface area will readily react with oxygen, causing an exponential increase in temperature and resulting in oxidation. On the other hand, composites with a low surface area will undergo slower passivation and generate very little heat. While the latter case may seem most ideal, alternative passivation methods are needed to reduce oxygen content and maintain the silicon's morphology immediately after deposition in order to better understand and utilize the potentially improved electrochemical cycle stability of composites with a higher surface area (smaller silicon dimensions). The inventions disclosed herein outline several methods for passivating the surface of a silicon material immediately after deposition by exposing it to a mild (non-oxygen) gas species in order to maintain a low exothermic temperature and thus provide the minimum oxygen content and maximum capacity that can be achieved.

[0136] Methods for passivating silicon films containing nanocrystals and silicon surfaces containing particles have been described in prior literature (e.g., Sun et al., 2016, “Heterogeneous reduction of carbon dioxide by hydride-terminated silicon nanocrystals” Nature Communications, 7:1-9; Cicero et al., 2000, “Photoreactivity of Unsaturated Compounds with Hydrogen-Terminated Silicon (111),” Langmuir 16:5688-5695; Cai et al., 2004, “Direct electrical detection of DNA Hybridization at DNA-modified silicon surfaces,” Biosensors and Bioelectronics 19:1013-1019 (2004)). However, these prior art methods do not address the very different and extremely difficult challenge of passivating the surface of amorphous nanoscale silicon present within the pores of porous carbon scaffolds. In other words, prior art does not address how to passivate the surface of silicon manufactured by CVI (i.e., silicon impregnated into the pores of a porous carbon scaffold by CVI).

[0137] The function of this invention is to mitigate the over-oxidation of silicon resulting from the silane CVI reaction. The above reaction will yield a Si-C composite with a high surface area and low oxygen content. By controlling the time, temperature, and gas species and concentration, it will be possible to influence the passivation properties of silicon, maintain the amorphous structure immediately after deposition, and increase the Li-ion capacity. Furthermore, although not theoretically bound, such passivation of silicon produced by CVI leads to an improvement in the rated capacity of Li-ions by minimizing the thickness of the oxide film.

[0138] When silane-derived silicon with a large surface area is suddenly exposed to air, severe exothermic oxidation occurs. This oxidation can be exacerbated by thermal runaway, which can completely oxidize the present silicon (i.e., render it inert / unusable) and raise flammability safety concerns. This invention addresses the issue of spontaneously combustible silane-derived silicon with a large surface area (especially 500 m²). 2 The associated challenges when depositing on substrates (greater than / g) are addressed by enabling stepwise controlled passivation of the material.

[0139] In some embodiments, silicon produced by CVI may be passivated by cooling the silicon-carbon material immediately after production under a nitrogen flow to a temperature lower than the CVI reaction temperature, and then by introducing air, or alternatively, oxygen gas in a pure form, or oxygen gas mixed with nitrogen gas in various proportions. The above cooling temperatures are, for example, below 400°C, or below 350°C, or below 300°C, or below 250°C, or below 200°C, or below 150°C, or below 100°C, or below 50°C, etc. For example, the passivation gas flow may contain 1% oxygen and 99% nitrogen, or 5% oxygen and 95% nitrogen, or 10% oxygen and 90% nitrogen, or 15% oxygen and 85% nitrogen, or 20% oxygen and 80% nitrogen, or the passivation gas flow may contain a mixture of nitrogen gas with more than 20% oxygen gas.

[0140] Typical low-temperature chemical vapor deposition (CVD) reactions involving gaseous precursors based on hydrogen compounds (e.g., silanes) result in highly disordered nanofilms / particles, which often exhibit an inherent tendency to oxidize or passivate when exposed to atmospheric conditions. The degree to which this occurs and the exothermic nature of the reaction are most strongly determined by the particle size and crystallinity of the material immediately after deposition. In the case of polycrystalline growth carried out by the solar power industry, deposition conditions are often very high temperatures (above 600°C) and in the form of thick films or granular particles. These materials not only exhibit high crystallinity but also very low surface area, resulting in very slow and mild reactivity when exposed to air, thus requiring little control over the degree of passivation.

[0141] In contrast to the prior art, the present invention discloses a method for passivating silicon produced by CVI (e.g., silicon produced by CVI in the pores of a porous carbon scaffold). CVI of low-temperature elemental silicon is used to passivate high-surface-area materials (e.g., 500 m²) having a highly tortuous, porous, and irregular morphology. 2 Surface area exceeding / g, and 0.4cm 3When carried out on particulate porous carbon containing a total pore volume greater than 1 / g, the silicon structure is highly disordered (amorphous), contains a high proportion of reactive hydrogen bonds at the surface ends, and is very small in size (e.g., less than 200 nm, or less than 100 nm, or less than 50 nm, or less than 30 nm, or less than 20 nm, or less than 10 nm, or less than 5 nm, or less than 3 nm, or less than 2 nm, or less than 1 nm). These material properties result in a dramatic decrease in the activation energy required for silicon oxidation under atmospheric conditions, thus leading to uncontrolled and often unsafe reactivity (spontaneous combustion) to oxygen when exposed to air. The material can undergo thermal runaway, combustion, and possibly complete oxidation to form dioxide. Thermal runaway is numerically defined herein as the silicon-carbon composite after silane CVI treatment being removed from the reactor at less than 50°C and heated to a temperature greater than 50°C when exposed to air. To control the degree of oxidation of nanosilicon immediately after deposition, the passivation method must be carefully controlled, as described in the present invention, so as to satisfy thermodynamic susceptibility but limit kinetic reactivity.

[0142] When using air as a passivation agent, it is important to limit the reactant (oxygen) concentration at the start of exposure to amorphous silicon immediately after deposition to minimize thermal runaway. In one embodiment, following silicon CVI on a porous carbon scaffold, the material is cooled to below 100°C under an inert gas, and then air is slowly introduced into the reaction chamber, initially with a total diluted oxygen content of 1 vol%. Sufficient time may be allowed to ensure complete purging of the chamber volume and a stoichiometric excess of O:Si. Here, the oxygen concentration is gradually increased by reducing the inert gas flow through the chamber (e.g., about 5, 10, 15, and finally 20 vol% oxygen), taking into account sufficient purging time and a stoichiometric excess of O:Si. Passivation is considered complete when the oxygen concentration reaches the concentration of ambient air, and the sample can then be safely removed from the reaction chamber.

[0143] In another embodiment, following silicon CVI on a porous carbon scaffold, the material is cooled to below 100°C under an inert gas, and then the pressure is reduced (e.g., below 700 Torre, or below 600 Torre, or below 500 Torre, or below 300 Torre, or below 100 Torre, or below 50 Torre, or below 30 Torre, or below 20 Torre, or below 10 Torre, or below 5 Torre, or below 3 Torre, or below 2 Torre, or below 1 Torre). Then, air is gradually introduced and retained for a certain period of time (e.g., 1 minute, or 5 minutes, or 10 minutes, or 20 minutes, or 30 minutes, or 60 minutes) until a certain pressure is reached (e.g., 50 Torre, or 100 Torre, or 200 Torre, or 300 Torre, or 500 Torre, or 600 Torre, or 760 Torre). In this method, it is not necessary to control the dilution of the air with an inert gas flow, and instead vacuum is used as a “diluent”. The advantage of this method is that the resulting partial vacuum conditions reduce convective heat flow, mitigating thermal runaway before it can occur. While not bound by theory, the reduction in pressure before passivation is important in the passivation of silicon within carbon pores, and therefore silicon produced by CVI, for example, which cannot approach the gas phase relatively easily, exhibits a very different situation compared to prior art for the passivation of silicon present on a surface, which can approach the gas phase relatively easily.

[0144] Apart from controlling the concentration and distribution of the oxygen reagent, passivation of silicon can also be achieved by utilizing the reactivity of surface-terminal hydrogen (Si-H) bonds through chemical reactions known in the art. In one such embodiment, after depositing silicon on a porous substrate, the material is cooled / heated to about 400°C under an inert gas. At this point, carbon dioxide is introduced into the furnace and undergoes a self-terminating hydride exchange reaction with the Si-H surface groups (Si-H + CO2 → Si-OH + CO), thus ultimately producing hydroxyl terminals that do not oxidize further when exposed to air.

[0145] In another further embodiment, after depositing silicon on a porous substrate, the material is cooled / heated to 100-200°C under an inert gas. Here, an alkene or alkyne gas (e.g., ethylene, propylene, or acetylene) is introduced into the furnace and allowed to remain for a certain period (e.g., 1-24 hours) to undergo a self-terminating hydrosilylation reaction with the Si-H surface group (Si-H + R1=R2 → Si-R1H-R2), thus ultimately yielding alkyl ends that do not oxidize further upon exposure to air. This particular passivation reaction is advantageous because it does not generate byproducts and does not impart oxygen content, thereby mitigating the formation of irreversible Li-O byproducts in Li-ion batteries and potentially improving the electrochemical performance of the anode.

[0146] Another approach to air passivation, as described above, would involve, after depositing silicon on a porous substrate, cooling the material to below 100°C, evacuating the chamber, and backfilling it with enough oxygen to stoichiometrically react with the silicon monolayer surface. The chamber would then be held under these conditions for a predetermined time (e.g., several hours) sufficient for passivation and heat loss to occur. This method would ensure the minimum amount of oxygen necessary for the formation of an oxide film that prevents further oxidation.

[0147] In passivation using hydrosilylation reactions, specific advantageous characteristics (not limited to, but such as hydrophobicity, covalent bridging with common Li-ion anode binders, or artificial SEI) can be imparted by preparing certain alkenes.

[0148] In passivation using carbon dioxide or hydrosilylation, UV light can be used to initiate the reaction instead of heat. This would have the advantage of limiting further diffusion of CO2 into the silicon bulk by keeping the material at a low temperature (ambient temperature).

[0149] In some embodiments, the passivation gas contains oxygen species and is liquid at room temperature. In such embodiments, the reaction between the passivation gas and silicon not only achieves the desired passivation of the silicon surface but also, though not theoretically bound, causes chemical modification of the surface, thereby improving the electrochemical properties and / or stability of the silicon material. In this regard, in some embodiments, passivation forms silyl ether species, resulting in improved performance when the silicon-carbon composite material is used as an anode for lithium-ion batteries (e.g., providing a more stable SEI, improved calendar life, improved cycle life, and / or improved performance at high temperatures such as 45°C or 60°C).

[0150] Examples of passivation gases in silicon passivation produced by CVI are not particularly limited, but include, for example, oxygen, carbon dioxide, water, methanol, ethanol, propanol, butanol, dimethyl carbonate, ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, vinylene carbonate, fluoroethylene carbonate, and mixtures thereof.

[0151] In certain embodiments, the present invention includes a method for passivating the surface of a hydrogen-terminated silicon-carbon composite using alkene and / or alkyne species to improve ambient temperature (storage life) and electrochemical stability at the anode of a Li-ion battery. In such composites produced by CVI using a silicon-containing gas, e.g., silane as the silicon precursor, the silicon in the resulting silicon-carbon composite is amorphous, and such a structure tends to oxidize rapidly (thermally runaway) unless completely passivated.

[0152] Prior to this invention, the most advanced passivation of silicon immediately after synthesis involved simply introducing air into the newly synthesized silicon-carbon composite material, which remained in the CVI furnace or a cooled chamber downstream of the CVI furnace after the completion of the CVI process. However, this modern approach presents a challenge: the required degree of oxidation can vary dramatically depending on the final surface area of ​​the composite. The higher the surface area of ​​the newly synthesized silicon-carbon composite, the more readily the material reacts with oxygen, leading to a rapid temperature increase, thus further accelerating the reaction and potentially causing thermal runaway. In contrast, the lower the surface area of ​​the newly synthesized silicon-carbon composite, the more slowly the material reacts with oxygen, thus resulting in corresponding heat loss. Consequently, the above-mentioned state-of-the-art approach to passivating newly synthesized silicon-carbon composite materials is extremely difficult to control beyond the laboratory to the relevant commercial manufacturing scale.

[0153] Therefore, the present invention is 2m 2 Surface area greater than / g (e.g., 5m 2 / g or more, for example, 10m 2 / g or more, for example, 15m 2 / g or more, for example, 20m 2 / g or more, for example, 25m 2 / g or more, for example, 30m 2 / g or more, for example, 40m 2 / g or more, for example, 50m 2 / g or more, for example, 100m 2 It is useful in the passivation of newly synthesized silicon-carbon composite materials containing (more than / g).

[0154] In certain embodiments, passivation of the surface of hydrogen-terminated silicon materials by exposure to mild (oxygen-free) organic species via gas-phase reactions (including, but not limited to, hydrosilylation reactions) not only mitigates exothermic behavior and improves stability for commercial production, but also results in the lowest oxygen content achievable in silicon-carbon composites. This content can be expressed as the molar ratio of oxygen to silicon in the silicon-carbon composite. In a particular embodiment, after passivation of the surface of the hydrogen-terminated silicon material by exposure to organic species via a gas-phase hydrosilylation reaction, the molar ratio of oxygen to silicon is less than 0.5 mol / mol, for example less than 0.4 mol / mol, for example less than 0.3 mol / mol, for example less than 0.2 mol / mol, for example less than 0.1 mol / mol, for example less than 0.09 mol / mol, for example less than 0.08 mol / mol, for example less than 0.07 mol / mol, for example less than 0.06 mol / mol, for example less than 0.05 mol / mol, for example less than 0.04 mol / mol, for example less than 0.03 mol / mol, for example less than 0.02 mol / mol, for example less than 0.01 mol / mol, for example less than 0.005 mol / mol, for example less than 0.001 mol / mol.

[0155] In certain embodiments, passivation of the surface of a hydrogen-terminated silicon material by exposure to mild (oxygen-free) organic species via a gas-phase reaction (including, but not limited to, a hydrosilylation reaction for example) alleviates the exothermic behavior and improves the stability of commercial manufacturing. Moreover, in a silicon-carbon composite, when the silicon-carbon composite powder is exposed to ambient conditions (i.e., room temperature of about 25 °C and ambient oxygen), it results in a very stable oxygen content. In certain embodiments, the molar ratio of oxygen to silicon when the silicon-carbon composite powder is exposed to ambient conditions increases by less than 0.01 mol / mol per day, such as less than 0.009 mol / mol per day, such as less than 0.008 mol / mol per day, such as less than 0.007 mol / mol per day, such as less than 0.006 mol / mol per day, such as less than 0.005 mol / mol per day, such as less than 0.004 mol / mol per day, such as less than 0.003 mol / mol per day, such as less than 0.002 mol / mol per day, such as less than 0.001 mol / mol per day, such as less than 0.0009 mol / mol per day, such as less than 0.0008 mol / mol per day, such as less than 0.0007 mol / mol per day, such as less than 0.0006 mol / mol per day, such as less than 0.0005 mol / mol per day, such as less than 0.0004 mol / mol per day, such as less than 0.0003 mol / mol per day, such as less than 0.0002 mol / mol per day, such as less than 0.0001 mol / mol per day, such as less than 0.00005 mol / mol per day, such as less than 0.00001 mol / mol per day.

[0156] Similarly, the low ratio of oxygen to silicon in the silicon-carbon composite in the above embodiments not only imparts a lower reactivity to the silicon-carbon composite, but also makes the molar ratio of the oxygen content to silicon more stable, thus improving and maintaining excellent cycle life and calendar life when used as an anode in a lithium-ion battery.

[0157] In certain embodiments, passivation of the surface of the hydrogen-terminated silicon material within the silicon-carbon composite material is achieved via a hydrosilylation reaction. In some embodiments, the hydrosilylation reaction is a gas-solid reaction, i.e., a reaction between a passivating agent that is present primarily as a gas under passivation reaction conditions and a solid silicon-carbon composite. In other embodiments, the hydrosilylation reaction is a liquid-solid reaction, i.e., a reaction between a passivating agent that is present primarily as a liquid under passivation reaction conditions and a solid silicon-carbon composite.

[0158] The passivators selected may vary, and their properties impart desirable properties to the manufactured passivated silicon-carbon composite material. For example, a passivator having an ether functional group, when used as a passivator to passivate the surface of hydrogen-terminated silicon material in a silicon-carbon composite, results in a passivated silicon-carbon composite with improved ionic conductivity. In another embodiment, a passivator having a carbonate group, when used as a passivator to passivate the surface of hydrogen-terminated silicon material in a silicon-carbon composite, results in a passivated silicon-carbon composite that forms a more stable SEI layer when used as an anode active material cycled in a lithium-ion battery. In yet another embodiment, a passivator having an epoxy group, when used as a passivator to passivate the surface of hydrogen-terminated silicon material in a silicon-carbon composite, results in a passivated silicon-carbon composite that forms a bond with a binder (e.g., polyacrylic acid) in the anode formulation, improving the performance of the silicon-carbon composite when it is cycled as an anode active material in a lithium-ion battery. In yet another embodiment, a passivator containing a fluoride, when used as a passivator to passivate the surface of hydrogen-terminated silicon material in a silicon-carbon composite, results in a passivated silicon-carbon composite that forms a more stable SEI layer when used as an anode active material cycled in a lithium-ion battery. In yet another embodiment, a passivator containing a nitrogen-containing functional group (e.g., amines and amides, etc.), when used as a passivator to passivate the surface of hydrogen-terminated silicon material in a silicon-carbon composite, provides a passivated silicon-carbon composite having properties that combine those of the above examples (including improved ionic conductivity and bonding).

[0159] Example 1. Manufacturing of silicon-carbon composite material by CVI. The physical properties of the carbon scaffold (carbon scaffold 1) used in the manufacturing of the silicon-carbon composite are shown in Table 3 below. Using carbon scaffold 1, the silicon-carbon composite (silicon-carbon composite 1) was manufactured by CVI as follows: 0.2 grams of amorphous porous carbon was placed in a 2-inch x 2-inch ceramic crucible and positioned in the center of a horizontal tubular furnace. The furnace was sealed and purged with nitrogen gas at 500 cubic centimeters (ccm) per minute. The furnace temperature was increased by 20°C per minute to a peak temperature of 450°C and maintained for 30 minutes. At this point, the nitrogen gas was shut off, and then silane and hydrogen were introduced at flow rates of 50 ccm and 450 ccm, respectively, over a total of 30 minutes. Subsequently, the silane and nitrogen were shut off, nitrogen was reintroduced into the furnace, and the internal air was purged. At the same time, the furnace heating was stopped and it was allowed to cool down to ambient temperature. The finished Si-C material was then removed from the furnace.

[0160] Description of the carbon scaffold used in Example 1 [Table 3]

[0161] Example 2. Analysis of various silicon-composite materials. Carbon scaffold materials using various carbon scaffold materials were characterized by nitrogen adsorption gas analysis, and specific surface area, total pore volume, and the percentage of pore volume including micropores, mesopores, and macropores were measured. The characterization data for the carbon scaffold materials, i.e., the surface area, pore volume, and pore volume distribution (percentage of micropores, mesopores, and macropores) of the carbon scaffolds (all measured by nitrogen adsorption analysis), are shown in Table 4.

[0162] Physical properties of various carbon scaffold materials [Table 4]

[0163] Using the carbon scaffold samples listed in Table 4, various silicon-carbon composite materials were fabricated by the CVI method in a static bed configuration, as generally described in Example 1. These silicon-carbon samples were prepared under process conditions ranging from silane concentration of 1.25% to 100%; dilution gas of nitrogen or hydrogen; and starting mass of carbon scaffold of 0.2 g to 700 g.

[0164] The surface area of ​​the silicon-carbon composite was measured. Furthermore, the silicon content and Z of the silicon-carbon composite were determined by TGA analysis. The silicon-carbon composite material was tested in a half-cell coin cell. The anode of the half-cell coin cell can contain 60-90% silicon-carbon composite, 5-20% Na-CMC (as a binder), and 5-20% Super C45 (as a conductivity enhancer), and the electrolyte can contain 2:1 ethylene carbonate:diethylene carbonate, 1M LiPF6, and 10% fluoroethylene carbonate. The half-cell coin cell can be cycled for 5 cycles at 25°C and a rate of C / 5, and then cycled at a rate of C / 10. The voltage can be cycled from 0V to 0.8V, or alternatively, from 0V to 1.5V. From the data of half-cell and coin cells, the maximum capacity can be measured, and the average Coulomb efficiency (CE) from cycle 7 to cycle 20 can also be measured. The physicochemical and electrochemical properties of various silicon-carbon composite materials are shown in Table 5.

[0165] The oxygen, nitrogen, and hydrogen content of silicon-carbon composites was measured using an inert gas melting apparatus known in the art (LECO ONH 836). Silicon-carbon composite samples were flash-heated to approximately 3000°C in a graphite arc furnace under a helium gas flow. Oxygen in the samples was carbonothermally reduced to CO2 and / or CO, introduced into the helium gas flow, and quantified downstream using an IR spectrophotometer. Hydrogen was released from the sample in the form of H2, catalytically converted to H2O in the gas phase, and also quantified using an IR spectrophotometer. Finally, nitrogen was released from the sample in the form of N2 and quantified using a thermal conductivity detector. The results are presented as the percentage of elemental weight relative to the total weight of the sample.

[0166] Properties of various silicon-carbon materials [Table 5]

[0167] Figure 1 shows a plot of the average Coulomb efficiency as a function of Z. As can be seen, the average Coulomb efficiency for silicon-carbon samples with low Z values ​​increased dramatically. In particular, all silicon-carbon samples with Z less than 10.0 showed an average Coulomb efficiency of 0.9941 or higher, and all silicon-carbon samples with Z greater than 10 (silicon-carbon composite samples 12 to 16) were observed to have an average Coulomb efficiency of 0.9909 or lower. Although not bound by theory, the higher Coulomb efficiency in silicon-carbon samples with Z less than 10 results in superior cycle stability in full-cell lithium-ion batteries. Further investigation of the table revealed a surprising and unexpected result: a combination of silicon-carbon composite samples with Z less than 10 and silicon-carbon composite samples further containing carbon scaffolds with microporosity greater than 70 showed an average Coulomb efficiency of 0.995 or higher.

[0168] Therefore, in a more preferred embodiment, the silicon-carbon composite material includes Z less than 10, for example Z less than 5, for example Z less than 3, for example Z less than 2, for example Z less than 1, for example Z less than 0.5, for example Z less than 0.1, or Z 0.

[0169] In certain preferred embodiments, the silicon-carbon composite material comprises a carbon scaffold having a Z of less than 10 and a microporosity of more than 70%, for example, a Z of less than 10 and a microporosity of more than 80%, for example, a Z of less than 10 and a microporosity of more than 90%, for example, a Z of less than 10 and a microporosity of more than 95%, for example, a Z of less than 5 and a microporosity of more than 70%, for example, a Z of less than 5 and a microporosity of more than 80%, for example, a Z of less than 5 and a microporosity of more than 90%, for example, a Z of less than 3 and a microporosity of more than 70%, for example, a Z of less than 3 and a microporosity of more than 80%, for example, a Z of less than 3 and a microporosity of more than 95%, for example, a Z of less than 2 and a microporosity of more than 70%, for example, a Z of less than 2 and a microporosity of more than 80%, for example, a Z of less than 2 and a microporosity of more than 90%, for example, 2 Microporosity less than Z and greater than 95%, e.g., Z less than 1 and greater than 70%, e.g., Z less than 1 and greater than 80%, e.g., Z less than 1 and greater than 90%, e.g., Z less than 1 and greater than 95%, e.g., Z less than 0.5 and greater than 70%, e.g., Z less than 0.5 and greater than 80%, e.g., Z less than 0.5 and greater than 90%, e.g., Z less than 0.5 and 95 This includes microporosity greater than % (e.g., Z less than 0.1) and microporosity greater than 70%, for example, Z less than 0.1 and microporosity greater than 80%, for example, Z less than 0.1 and microporosity greater than 90%, for example, Z less than 0.1 and microporosity greater than 95%, for example, Z 0 and microporosity greater than 70%, for example, Z 0 and microporosity greater than 80%, for example, Z 0 and microporosity greater than 90%, for example, Z 0 and microporosity greater than 95%, etc.

[0170] In certain preferred embodiments, the silicon-carbon composite material has a Z of less than 10, a microporosity of more than 70%, silicon content of 15% to 85%, and 100m 2 Includes a surface area of ​​less than / g, for example, Z less than 10, microporosity greater than 70%, silicon 15% to 85%, and 50m 2 Surface area less than / g, e.g., Z less than 10, microporosity greater than 70%, silicon 15% to 85%, and 30m 2 Surface area less than / g, e.g., Z less than 10, microporosity greater than 70%, silicon 15% to 85%, and 10m 2 Surface area less than / g, e.g., Z less than 10, microporosity greater than 70%, silicon 15% to 85%, and 5m 2 Surface area less than / g, e.g., Z less than 10, microporosity greater than 80%, silicon 15% to 85%, and 50m 2 Surface area less than / g, e.g., Z less than 10, microporosity greater than 80%, silicon 15% to 85%, and 30m 2 Surface area less than / g, e.g., Z less than 10, microporosity greater than 80%, silicon 15% to 85%, and 10m 2 Surface area less than / g, e.g., Z less than 10, microporosity greater than 80%, silicon 15% to 85%, and 5m 2 Surface area less than / g, e.g., Z less than 10, microporosity greater than 90%, silicon 15% to 85%, and 50m 2 Surface area less than / g, e.g., Z less than 10, microporosity greater than 90%, silicon 15% to 85%, and 30m 2 Surface area less than / g, e.g., Z less than 10, microporosity greater than 90%, silicon 15% to 85%, and 10m 2 Surface area less than / g, e.g., Z less than 10, microporosity greater than 90%, silicon 15% to 85%, and 5m 2 Surface area less than / g, e.g., Z less than 10, microporosity greater than 95%, silicon 15% to 85%, and 50m 2 Surface area less than / g, e.g., Z less than 10, microporosity greater than 95%, silicon 15% to 85%, and 30m2 Surface area less than / g, e.g., Z less than 10, microporosity greater than 95%, silicon between 15% and 85%, and 10m 2 Surface area less than / g, e.g., Z less than 10, microporosity greater than 95%, silicon 15% to 85%, and 5m 2 Includes surface area less than / g, etc.

[0171] In certain preferred embodiments, the silicon-carbon composite material has a Z of less than 10, a microporosity of more than 70%, a silicon content of 30% to 60%, and 100m 2 Includes a surface area of ​​less than / g, for example, Z less than 10, microporosity greater than 70%, silicon 30% to 60%, and 50m 2 Surface area less than / g, e.g., Z less than 10, microporosity greater than 70%, silicon 30% to 60%, and 30m 2 Surface area less than / g, e.g., Z less than 10, microporosity greater than 70%, silicon 30% to 60%, and 10m 2 Surface area less than / g, e.g., Z less than 10, microporosity greater than 70%, silicon 30% to 60%, and 5m 2 Surface area less than / g, e.g., Z less than 10, microporosity greater than 80%, silicon 30% to 60%, and 50m 2 Surface area less than / g, e.g., Z less than 10, microporosity greater than 80%, silicon 30% to 60%, and 30m 2 Surface area less than / g, e.g., Z less than 10, microporosity greater than 80%, silicon 30% to 60%, and 10m 2 Surface area less than / g, e.g., Z less than 10, microporosity greater than 80%, silicon 30% to 60%, and 5m 2 Surface area less than / g, e.g., Z less than 10, microporosity more than 90%, silicon 30% to 60%, and 50m 2 Surface area less than / g, e.g., Z less than 10, microporosity more than 90%, silicon 30% to 60%, and 30m 2 Surface area less than / g, e.g., Z less than 10, microporosity more than 90%, silicon 30% to 60%, and 10m 2Surface area less than / g, e.g., Z less than 10, microporosity more than 90%, silicon 30% to 60%, and 5m 2 Surface area less than / g, e.g., Z less than 10, microporosity greater than 95%, silicon 30% to 60%, and 50m 2 Surface area less than / g, e.g., Z less than 10, microporosity greater than 95%, silicon 30% to 60%, and 30m 2 Surface area less than / g, e.g., Z less than 10, microporosity greater than 95%, silicon 30% to 60%, and 10m 2 Surface area less than / g, e.g., Z less than 10, microporosity more than 95%, silicon 30% to 60%, and 5m 2 Includes surface area less than / g, etc.

[0172] In certain preferred embodiments, the silicon-carbon composite material has a carbon scaffold with a Z of less than 10 and more than 80% micropolycity, and 30-60% silicon, 30m 2 This includes a surface area of ​​less than 0.9969 / g and an average Coulomb efficiency of 0.9969 or higher. For example, a silicon-carbon composite material has a Z of less than 10, a carbon scaffold with more than 80% micropolycity, 30-60% silicon, and 30m 2 This includes a surface area of ​​less than 0.9970 / g and an average Coulomb efficiency of 0.9970 or higher. For example, silicon-carbon composite materials include a carbon scaffold with a Z of less than 10, a micropolycity of more than 80%, and 30-60% silicon, 30m 2 This includes a surface area of ​​less than 0.9975 / g and an average Coulomb efficiency of 0.9975 or higher. For example, silicon-carbon composite materials include a carbon scaffold with a Z of less than 10, a micropolycity of more than 80%, and 30-60% silicon, 30m 2 This includes a surface area of ​​less than 0.9980 / g and an average Coulomb efficiency of 0.9980 or higher. For example, silicon-carbon composite materials have a Z of less than 10, a carbon scaffold with more than 80% micropolycity, 30-60% silicon, and 30m 2This includes a surface area of ​​less than 0.9985 / g and an average Coulomb efficiency of 0.9985 or higher. For example, silicon-carbon composite materials have a Z of less than 10, a carbon scaffold with more than 80% micropolycity, 30-60% silicon, and 30m 2 This includes a surface area of ​​less than 0.9990 / g and an average Coulomb efficiency of 0.9990 or higher. For example, silicon-carbon composite materials include a carbon scaffold with a Z of less than 10, a micropolycity of more than 80%, and 30-60% silicon, 30m 2 This includes a surface area of ​​less than 0.9995 / g and an average Coulomb efficiency of 0.9995 or higher. For example, silicon-carbon composite materials include a carbon scaffold with a Z of less than 10, micropolycity of more than 80%, and silicon of 30-60%, 30m 2 Includes surface area less than / g and average Coulomb efficiency of 0.9999 or greater.

[0173] Example 3. dV / dQ in various silicon-carbon composite materials. Differential capacitance curves (dQ / dV vs voltage) are commonly used as a non-destructive tool to understand phase transitions as a function of voltage in lithium battery electrodes (MN Obrovac et al. Structural Changes in Silicon Anodes during Lithium Insertion / Extraction, Electrochemical and Solid-State Letters, 7 (5) A93-A96 (2004); Ogata, K. et al. Revealing lithium-silicide phase transformations in nano-structured silicon-based lithium ion batteries via in situ NMR spectroscopy. Nat. Commun. 5:3217). As an alternative to dQ / dV vs voltage plotting, a strategy to obtain a similar analysis is to plot dQ vs V. As an example, the differential capacitance plot (dQ / dV vs voltage) was calculated from data obtained by galvanostatic cycling at a rate of 0.1C and a voltage range of 5mV to 0.8V in a half-cell coin cell at 25°C.Typical differential capacity curves of half cells vs lithium in silicon-based materials can be found in many references (Loveridge, M. J. et al. Towards High Capacity Li-Ion Batteries Based on Silicon-Graphene Composite Anodes and Sub-micron V-doped LiFePO4 Cathodes. Sci. Rep. 6, 37787; doi: 10.1038 / srep37787 (2016); M. N. Obrovac et al. Li15Si4Formation in Silicon Thin Film Negative Electrodes, Journal of The Electrochemical Society,163 (2) A255-A261 (2016); Q.Pan et al. Improved electrochemical performance of micro-sized SiO-based composite anode by prelithiation of stabilized lithium metal powder, Journal of Power Sources 347 (2017) 170-177). The lithiation behavior in the first cycle depends on, among other factors, the crystallinity of silicon and the oxygen content.

[0174] After the first cycle, previous amorphous silicon materials in the art show two distinct phase transition peaks in the dQ / dV vs V plot for lithiation and, similarly, two distinct phase transition peaks in the dQ / dV vs V plot for delithiation. For lithiation, one peak corresponds to the lithium-poor Li-Si alloy phase that occurs at 0.2 - 0.4 V, and the other peak corresponds to the lithium-rich Li-Si alloy phase that occurs at less than 0.15 V. For delithiation, one delithiation peak corresponds to the extraction of lithium that occurs at less than 0.4 V, and the other delithiation peak corresponds to the extraction of lithium that occurs at 0.4 V - 0.55 V. During lithiation, Li15 When the Si4 phase is formed, it is delithiated at approximately 0.45 V, resulting in a very narrow and sharp peak.

[0175] Figure 2 shows the dQ / dV vs voltage curve for cycle 2 in a silicon-carbon composite material corresponding to silicon-carbon composite 3 of Example 1. Silicon-carbon composite 3 contains Z at 0.6. For ease of identification, the plots are divided into regimes I, II, III, IV, V, and VI. Regimes I (0.8V~0.4V), II (0.4V~0.15V), and III (0.15V~0V) include the lithiation potential, while regimes IV (0V~0.4V), V (0.4V~0.55V), and VI (0.55V~0.8V) include the delithiation potential. As described above, the previous amorphous silicon-based materials in the art showed phase transition peaks at the lithiation potential in two regimes (regimes II and III), and phase transition peaks at the delithiation potential in two regimes (regimes IV and V).

[0176] As can be seen from Figure 2, the dQ / dV vs voltage curve revealed a surprising and unexpected result: silicon-carbon composite 3, containing Z 0.6, also exhibits two more peaks in the dQ / dV vs V curve, namely regime 1 at the lithiation potential and regime VI at the delithiation potential. As shown in Figure 3, all six peaks are reversible and are similarly observed in subsequent cycles.

[0177] While not bound by theory, the trimodal behavior of the dQ / dV vs V curve described above is novel and reflects a new form of silicon.

[0178] In particular, the novel peaks observed in regimes I and VI are more pronounced in certain scaffold matrices and are completely absent in other samples indicating prior art (silicon-carbon composite samples with Z greater than 10; see description and table below).

[0179] Figure 4 shows the dQ / dV vs V curve for silicon-carbon composite 3, which exhibits clear novel peaks in regimes I and VI. In contrast, Figure 4 also shows the dQ / dV vs V curves for silicon-carbon composites 15, 16, and 14 (all three samples containing Z values ​​greater than 10), which lack any peaks in regimes I and VI.

[0180] While not bound by theory, these novel peaks observed in regimes I and VI are related to the properties of silicon impregnated into the porous carbon scaffold, i.e., related to the interaction and properties between the porous carbon scaffold, the silicon impregnated into the porous carbon scaffold by CVI, and lithium. To provide a quantitative analysis, the inventors have expressed the following equation as peak I normalized with respect to peak III: φ = (Maximum peak height dQ / dV in Regime I) / (Maximum peak height dQ / dV in Regime III) [Here, dQ / dV was measured in a half-cell coin cell, with regime 1 being 0.8V to 0.4V and regime III being 0.15V to 0V; the half-cell coin cell was manufactured as known in the art.] The parameter φ, which is calculated using the formula, was defined. If a Si-C sample exhibits a graphite-related peak in regime III of the differential curve, the Li-Si-related phase transition peak for the calculation of coefficient D is given priority, and the former peak is removed. In this example, the half-cell coin cell contains an anode with 60-90% silicon-carbon composite, 5-20% SBR-Na-CMC, and 5-20% Super C45. An example of the calculation of φ for silicon-carbon composite 3 is shown in Figure 5. In this example, the maximum peak height in regime I was -2.39, found at 0.53V. Similarly, the maximum peak height in regime III was -9.71 at 0.04V. In this example, φ can be calculated using the above formula, and φ = -2.39 / -9.71 = 0.25 was obtained. The value of φ was obtained from half-cell coin cell data for various silicon-carbon composites shown in Example 2. These data are summarized in Table 6. Table 6 also includes data on the first cycle efficiency measured in half-cell coin cells at cycles of 5mV to 0.8V.

[0181] Physical properties of various silicon-carbon materials [Table 6] The parenthetical data for the first cycle efficiency were measured within a voltage window of 5mV to 1.5V.

[0182] The data in Table 6 revealed an unexpected relationship between decreasing Z and increasing φ. All silicon-carbon composites with Z less than 10 had a φ of 0.13 or greater, and all silicon-carbon composites with Z greater than 10 had a φ of less than 0.13. Conversely, all silicon-carbon composites with Z greater than 10 had a φ of 0. This relationship is also clearly shown in Figure 6. Although not bound by theory, silicon materials containing a φ of 0.10 or greater (e.g., φ of 0.13 or greater, e.g., φ of 0.15 or greater, e.g., φ of 0.20 or greater, e.g., φ of 0.25 or greater, e.g., φ of 0.30 or greater) correspond to novel forms of silicon. Separately, silicon materials containing a φ greater than 0 also correspond to novel forms of silicon. Although not bound by theory, silicon materials containing a φ greater than 0 are characteristic of silicon materials that are amorphous, nano-sized, or silicon trapped in pores (e.g., in the pores of porous carbon scaffolds). Silicon-carbon composite materials containing silicon with a diameter of 0.10 or greater (e.g., 0.13 or greater, 0.15 or greater, 0.20 or greater, 0.25 or greater, 0.30 or greater) correspond to novel silicon-carbon composite materials. Separately, silicon-carbon composite materials containing a diameter greater than 0 also correspond to novel silicon-carbon composite materials.

[0183] In certain embodiments, the silicon-carbon composite includes φ of 0.1 or greater, φ of 0.11 or greater, φ of 0.12 or greater, φ of 0.13 or greater, φ of 0.14 or greater, φ of 0.15 or greater, φ of 0.16 or greater, φ of 0.17 or greater, φ of 0.18 or greater, φ of 0.19 or greater, φ of 0.20 or greater, φ of 0.24 or greater, φ of 0.25 or greater, φ of 0.30 or greater, or φ of 0.35 or greater. In one embodiment, φ is greater than 0. In some embodiments, φ is 0.001 or greater, φ is 0.01 or greater, φ is 0.02 or greater, φ is 0.05 or greater, φ is 0.1 or greater, φ is 0.11 or greater, or φ is 0.12 or greater.

[0184] In certain embodiments, the silicon-carbon composite material consists of a carbon scaffold with a Z of less than 10 and a microporosity of more than 70%, and 30-60% silicon, 100m 2 Includes a surface area of ​​less than / g and a diameter of 0.1 or greater, for example, Z less than 10, microporosity greater than 70%, silicon content of 30-60%, and 50m 2 Surface area less than / g, and φ greater than 0.1, e.g., Z less than 10, microporosity greater than 70%, silicon 30-60%, 30m 2 Surface area less than / g, and φ greater than 0.1, e.g., Z less than 10, microporosity greater than 70%, silicon 30-60%, 10m 2 Surface area less than / g, and φ greater than 0.1, e.g., Z less than 10, microporosity greater than 70%, 5m 2 This includes a surface area of ​​less than / g and a diameter of 0.1 or greater, etc.

[0185] In certain embodiments, the silicon-carbon composite material is a carbon scaffold with a Z of less than 10 and a microporosity of more than 70%, containing 40-60% silicon, and 100m 2 Includes a surface area of ​​less than / g and a diameter of 0.1 or greater, for example, Z less than 10, microporosity greater than 70%, silicon content of 40-60%, and 50m 2 Surface area less than / g, and diameter greater than 0.1, e.g., Z less than 10, microporosity greater than 70%, silicon content 40-60%, 30m 2 Surface area less than / g, and φ greater than 0.1, e.g., Z less than 10, microporosity greater than 70%, silicon 40-60%, 10m 2 Surface area less than / g, and diameter greater than 0.1, e.g., Z less than 10, microporosity greater than 70%, silicon 40-60%, 5m 2 This includes a surface area of ​​less than / g and a diameter of 0.1 or greater, etc.

[0186] In certain embodiments, the silicon-carbon composite material consists of a carbon scaffold with a Z of less than 10 and a microporosity of more than 70%, and 30-60% silicon, 100m 2Includes a surface area less than / g and a φ greater than 0, for example, Z less than 10, microporosity greater than 70%, silicon 30-60%, 50m 2 Surface area less than / g, and φ greater than 0, e.g., Z less than 10, microporosity greater than 70%, silicon 30-60%, 30m 2 Surface area less than / g, and φ greater than 0, e.g., Z less than 10, microporosity greater than 70%, silicon 30-60%, 10m 2 Surface area less than / g, and φ greater than 0, e.g., Z less than 10, microporosity greater than 70%, silicon 30-60%, 5m 2 This includes surface area less than / g, and φ greater than 0, etc.

[0187] In certain embodiments, the silicon-carbon composite material is a carbon scaffold with a Z of less than 10 and a microporosity of more than 70%, containing 40-60% silicon, and 100m 2 Includes a surface area less than / g and a φ greater than 0, for example, Z less than 10, microporosity greater than 70%, silicon 40-60%, 50m 2 Surface area less than / g, and φ greater than 0, e.g., Z less than 10, microporosity greater than 70%, silicon 40-60%, 30m 2 Surface area less than / g, and φ greater than 0, e.g., Z less than 10, microporosity greater than 70%, silicon 40-60%, 10m 2 Surface area less than / g, and φ greater than 0, e.g., Z less than 10, microporosity greater than 70%, silicon 40-60%, 5m 2 This includes surface area less than / g, and φ greater than 0, etc.

[0188] In certain embodiments, the silicon-carbon composite material is a carbon scaffold with a Z of less than 10 and a microporosity of more than 80%, containing 30-60% silicon, and 100m 2 Includes a surface area of ​​less than / g and a diameter of 0.1 or greater, for example, Z less than 10, microporosity greater than 80%, silicon content of 30-60%, and 50m 2 Surface area less than / g, and φ greater than 0.1, e.g., Z less than 10, microporosity greater than 80%, silicon 30-60%, 30m 2Surface area less than / g, and φ greater than 0.1, e.g., Z less than 10, microporosity greater than 80%, silicon 30-60%, 10m 2 Surface area less than / g, and diameter greater than 0.1, e.g., Z less than 10, microporosity greater than 80%, silicon content 30-60%, 5m 2 This includes a surface area of ​​less than / g and a diameter of 0.1 or greater, etc.

[0189] In certain embodiments, the silicon-carbon composite material is a carbon scaffold with a Z of less than 10 and a microporosity of more than 80%, containing 40-60% silicon, and 100m 2 Includes a surface area of ​​less than / g and a diameter of 0.1 or greater, for example, Z less than 10, microporosity greater than 80%, silicon content of 40-60%, and 50m 2 Surface area less than / g, φ greater than 0.1, for example Z less than 10, microporosity greater than 80%, silicon 40-60%, 30m 2 Surface area less than / g, and φ greater than 0.1, e.g., Z less than 10, microporosity greater than 80%, silicon 40-60%, 10m 2 Surface area less than / g, φ greater than 0.1, for example Z less than 10, microporosity greater than 80%, silicon 40-60%, 5m 2 This includes a surface area of ​​less than / g and a diameter of 0.1 or greater, etc.

[0190] In certain embodiments, the silicon-carbon composite material is a carbon scaffold with a Z of less than 10 and a microporosity of more than 80%, containing 30-60% silicon, and 100m 2 Includes a surface area less than / g and a φ greater than 0, for example, Z less than 10, microporosity greater than 80%, silicon 30-60%, 50m 2 Surface area less than / g, and φ greater than 0, e.g., Z less than 10, microporosity greater than 80%, silicon 30-60%, 30m 2 Surface area less than / g, and φ greater than 0, e.g., Z less than 10, microporosity greater than 80%, silicon 30-60%, 10m 2 Surface area less than / g, and φ greater than 0, e.g., Z less than 10, microporosity greater than 80%, silicon 30-60%, 5m2 This includes surface area less than / g, and φ greater than 0, etc.

[0191] In certain embodiments, the silicon-carbon composite material is a carbon scaffold with a Z of less than 10 and a microporosity of more than 80%, containing 40-60% silicon, and 100m 2 Includes a surface area less than / g and a φ greater than 0, for example, Z less than 10, microporosity greater than 80%, silicon 40-60%, 50m 2 Surface area less than / g, and φ greater than 0, e.g., Z less than 10, microporosity greater than 80%, silicon 40-60%, 30m 2 Surface area less than / g, and φ greater than 0, e.g., Z less than 10, microporosity greater than 80%, silicon 40-60%, 10m 2 Surface area less than / g, and φ greater than 0, e.g., Z less than 10, microporosity greater than 80%, silicon 40-60%, 5m 2 This includes surface area less than / g, and φ greater than 0, etc.

[0192] In certain embodiments, the silicon-carbon composite material is a carbon scaffold with a Z of less than 10 and a microporosity of more than 90%, containing 30-60% silicon, and 100m 2 Includes a surface area of ​​less than / g and a diameter of 0.1 or greater, for example, Z less than 10, microporosity greater than 90%, silicon 30-60%, 50m 2 Surface area less than / g, and φ greater than 0.1, e.g., Z less than 10, microporosity greater than 90%, silicon 30-60%, 30m 2 Surface area less than / g, and φ greater than 0.1, e.g., Z less than 10, microporosity greater than 90%, silicon 30-60%, 10m 2 Surface area less than / g, φ greater than 0.1, for example Z less than 10, microporosity greater than 90%, silicon 30-60%, 5m 2 This includes a surface area of ​​less than / g and a diameter of 0.1 or greater, etc.

[0193] In certain embodiments, the silicon-carbon composite material is a carbon scaffold with a Z of less than 10 and a microporosity of more than 90%, containing 40-60% silicon, and 100m 2 Includes a surface area of ​​less than / g and a diameter of 0.1 or greater, for example, Z less than 10, microporosity greater than 90%, silicon 40-60%, 50m 2 Surface area less than / g, and φ greater than 0.1, e.g., Z less than 10, microporosity greater than 90%, silicon 40-60%, 30m 2 Surface area less than / g, and φ greater than 0.1, e.g., Z less than 10, microporosity greater than 90%, silicon 40-60%, 10m 2 Surface area less than / g, and diameter greater than 0.1, e.g., Z less than 10, microporosity greater than 90%, silicon 40-60%, 5m 2 This includes a surface area of ​​less than / g and a diameter of 0.1 or greater, etc.

[0194] In certain embodiments, the silicon-carbon composite material is a carbon scaffold with a Z of less than 10 and a microporosity of more than 90%, containing 30-60% silicon, and 100m 2 Includes a surface area less than / g and a φ greater than 0, for example, Z less than 10, microporosity greater than 90%, silicon 30-60%, 50m 2 Surface area less than / g, and φ greater than 0, e.g., Z less than 10, microporosity greater than 90%, silicon 30-60%, 30m 2 Surface area less than / g, and φ greater than 0, e.g., Z less than 10, microporosity greater than 90%, silicon 30-60%, 10m 2 Surface area less than / g, and φ greater than 0, e.g., Z less than 10, microporosity greater than 90%, silicon 30-60%, 5m 2 This includes surface area less than / g, and φ greater than 0, etc.

[0195] In certain embodiments, the silicon-carbon composite material is a carbon scaffold with a Z of less than 10 and a microporosity of more than 90%, containing 40-60% silicon, and 100m 2Includes a surface area less than / g and a φ greater than 0, for example, Z less than 10, microporosity greater than 90%, silicon 40-60%, 50m 2 Surface area less than / g, and φ greater than 0, e.g., Z less than 10, microporosity greater than 90%, silicon 40-60%, 30m 2 Surface area less than / g, and φ greater than 0, e.g., Z less than 10, microporosity greater than 90%, silicon 40-60%, 10m 2 Surface area less than / g, and φ greater than 0, e.g., Z less than 10, microporosity greater than 90%, silicon 40-60%, 5m 2 This includes surface area less than / g, and φ greater than 0, etc.

[0196] In certain embodiments, the silicon-carbon composite material is a carbon scaffold with a Z of less than 10 and a microporosity of more than 95%, containing 30-60% silicon, and 100m 2 Includes a surface area of ​​less than / g and a diameter of 0.1 or greater, for example, Z less than 10, microporosity greater than 95%, silicon content of 30-60%, and 50m 2 Surface area less than / g, and φ greater than 0.1, e.g., Z less than 5, microporosity greater than 95%, silicon 30-60%, 30m 2 Surface area less than / g, and φ greater than 0.1, e.g., Z less than 10, microporosity greater than 95%, silicon 30-60%, 10m 2 Surface area less than / g, φ greater than 0.1, for example Z less than 10, microporosity greater than 95%, silicon 30-60%, 5m 2 This includes a surface area of ​​less than / g and a diameter of 0.1 or greater, etc.

[0197] In certain embodiments, the silicon-carbon composite material is a carbon scaffold with a Z of less than 10 and a microporosity of more than 95%, containing 40-60% silicon, and 100m 2 Includes a surface area of ​​less than / g and a diameter of 0.1 or greater, for example, Z less than 10, microporosity greater than 95%, silicon content of 40-60%, and 50m 2 Surface area less than / g, and diameter greater than 0.1, e.g., Z less than 10, microporosity greater than 95%, silicon content 40-60%, 30m2 Surface area less than / g, and φ greater than 0.1, e.g., Z less than 10, microporosity greater than 95%, silicon 40-60%, 10m 2 Surface area less than / g, φ greater than 0.1, for example Z less than 10, microporosity greater than 95%, silicon 40-60%, 5m 2 This includes a surface area of ​​less than / g and a diameter of 0.1 or greater, etc.

[0198] In certain embodiments, the silicon-carbon composite material is a carbon scaffold with a Z of less than 10 and a microporosity of more than 95%, containing 30-60% silicon, and 100m 2 Includes a surface area of ​​less than / g and a diameter of 0.1 or greater, for example, Z less than 10, microporosity greater than 95%, silicon content of 30-60%, and 50m 2 Surface area less than / g, and diameter greater than 0.1, e.g., Z less than 10, microporosity greater than 95%, silicon content 30-60%, 30m 2 Surface area less than / g, and φ greater than 0.1, e.g., Z less than 10, microporosity greater than 95%, silicon 30-60%, 10m 2 Surface area less than / g, φ greater than 0.1, for example Z less than 10, microporosity greater than 95%, silicon 30-60%, 5m 2 This includes a surface area of ​​less than / g and a diameter of 0.1 or greater, etc.

[0199] In certain embodiments, the silicon-carbon composite material is a carbon scaffold with a Z of less than 10 and a microporosity of more than 95%, containing 40-60% silicon, and 100m 2 Includes a surface area less than / g and a φ greater than 0, for example, Z less than 10, microporosity greater than 95%, silicon 40-60%, 50m 2 Surface area less than / g, and φ greater than 0, e.g., Z less than 10, microporosity greater than 95%, silicon 40-60%, 30m 2 Surface area less than / g, and φ greater than 0, e.g., Z less than 10, microporosity greater than 95%, silicon 40-60%, 10m 2Surface area less than / g, and φ greater than 0, e.g., Z less than 10, microporosity greater than 95%, silicon 40-60%, 5m 2 This includes surface area less than / g, and φ greater than 0, etc.

[0200] In certain embodiments, the silicon-carbon composite material consists of a carbon scaffold with a Z of less than 10 and a microporosity of more than 80%, and 30-60% silicon, 30m 2 This includes a surface area of ​​less than / g, a diameter of 0.15 or greater, and an average Coulomb efficiency of 0.9969 or greater, for example, a carbon scaffold with a Z of less than 10, a microporosity of more than 80%, 30-60% silicon, and 30m 2 Carbon scaffolds with a surface area of ​​less than / g, a diameter of 0.15 or greater, and an average Coulomb efficiency of 0.9970 or greater, e.g., a Z of less than 10, and a microporosity of over 80%, containing 30-60% silicon, and 30m 2 Carbon scaffolds with a surface area of ​​less than / g, a diameter of 0.15 or greater, and an average Coulomb efficiency of 0.9975 or greater, e.g., a Z of less than 10, and a microporosity of over 80%, 30-60% silicon, 30m 2 Carbon scaffolds with a surface area of ​​less than / g, a diameter of 0.15 or greater, and an average Coulomb efficiency of 0.9980 or greater, e.g., a Z of less than 10, and a microporosity of over 80%, containing 30-60% silicon, and 30m 2 Carbon scaffolds with a surface area of ​​less than / g, a diameter of 0.15 or greater, and an average Coulomb efficiency of 0.9985 or greater, e.g., a Z of less than 10, and a microporosity of over 80%, containing 30-60% silicon, and 30m 2 Carbon scaffolds with a surface area of ​​less than / g, a diameter of 0.15 or greater, and an average Coulomb efficiency of 0.9990 or greater, e.g., a Z of less than 10, and a microporosity of over 80%, containing 30-60% silicon, and 30m 2 Carbon scaffolds with a surface area of ​​less than / g, a diameter of 0.15 or greater, and an average Coulomb efficiency of 0.9995 or greater, e.g., a Z of less than 10, and a microporosity of over 80%, containing 30-60% silicon, and 30m 2Examples include a surface area of ​​less than / g, a diameter of 0.15 or greater, and an average Coulomb efficiency of 0.9999 or greater.

[0201] In certain embodiments, the silicon-carbon composite material consists of a carbon scaffold with a Z of less than 10 and a microporosity of more than 80%, and 30-60% silicon, 30m 2 This includes a surface area of ​​less than / g, a diameter of 0.20 or greater, and an average Coulomb efficiency of 0.9969 or greater, for example, a carbon scaffold with a Z of less than 10, a microporosity of more than 80%, 30-60% silicon, and 30m 2 Carbon scaffolds with a surface area of ​​less than / g, a diameter of 0.20 or greater, and an average Coulomb efficiency of 0.9970 or greater, e.g., a Z of less than 10, and a microporosity of over 80%, containing 30-60% silicon, and 30m 2 Carbon scaffolds with a surface area of ​​less than / g, a diameter of 0.20 or greater, and an average Coulomb efficiency of 0.9975 or greater, e.g., a Z of less than 10, and a microporosity of over 80%, containing 30-60% silicon, and 30m 2 Carbon scaffolds with a surface area of ​​less than / g, a diameter of 0.20 or greater, and an average Coulomb efficiency of 0.9980 or greater, e.g., a Z of less than 10, and a microporosity of over 80%, containing 30-60% silicon, and 30m 2 Carbon scaffolds with a surface area of ​​less than / g, a diameter of 0.20 or greater, and an average Coulomb efficiency of 0.9985 or greater, e.g., a Z of less than 10, and a microporosity of over 80%, containing 30-60% silicon, and 30m 2 Carbon scaffolds with a surface area of ​​less than / g, a diameter of 0.20 or greater, and an average Coulomb efficiency of 0.9990 or greater, e.g., a Z of less than 10, and a microporosity of over 80%, containing 30-60% silicon, and 30m 2 Carbon scaffolds with a surface area of ​​less than / g, a diameter of 0.20 or greater, and an average Coulomb efficiency of 0.9995 or greater, e.g., a Z of less than 10, and a microporosity of over 80%, containing 30-60% silicon, and 30m 2 Examples include a surface area of ​​less than / g, a diameter of 0.20 or greater, and an average Coulomb efficiency of 0.9999 or greater.

[0202] In certain embodiments, the silicon-carbon composite material consists of a carbon scaffold with a Z of less than 10 and a microporosity of more than 80%, and 30-60% silicon, 30m 2 This includes a surface area of ​​less than / g, a diameter of 0.25 or greater, and an average Coulomb efficiency of 0.9969 or greater, for example, a carbon scaffold with a Z of less than 10, a microporosity of more than 80%, 30-60% silicon, and 30m 2 Carbon scaffolds with a surface area of ​​less than / g, a diameter of 0.25 or greater, and an average Coulomb efficiency of 0.9970 or greater, e.g., a Z of less than 10, and a microporosity of over 80%, containing 30-60% silicon, and 30m 2 Carbon scaffolds with a surface area of ​​less than / g, a diameter of 0.25 or greater, and an average Coulomb efficiency of 0.9975 or greater, e.g., a Z of less than 10, and a microporosity of over 80%, containing 30-60% silicon, and 30m 2 Carbon scaffolds with a surface area of ​​less than / g, a diameter of 0.25 or greater, and an average Coulomb efficiency of 0.9980 or greater, e.g., a Z of less than 10, and a microporosity of over 80%, containing 30-60% silicon, and 30m 2 Carbon scaffolds with a surface area of ​​less than / g, a diameter of 0.25 or greater, and an average Coulomb efficiency of 0.9985 or greater, e.g., a Z of less than 10, and a microporosity of over 80%, containing 30-60% silicon, and 30m 2 Carbon scaffolds with a surface area of ​​less than / g, a diameter of 0.25 or greater, and an average Coulomb efficiency of 0.9990 or greater, e.g., a Z of less than 10, and a microporosity of over 80%, containing 30-60% silicon, and 30m 2 Carbon scaffolds with a surface area of ​​less than / g, a diameter of 0.25 or greater, and an average Coulomb efficiency of 0.9995 or greater, e.g., a Z of less than 10, and a microporosity of over 80%, 30-60% silicon, 30m 2 Examples include a surface area of ​​less than / g, a diameter of 0.25 or greater, and an average Coulomb efficiency of 0.9999 or greater.

[0203] In certain embodiments, the silicon-carbon composite material consists of a carbon scaffold with a Z of less than 10 and a microporosity of more than 80%, and 30-60% silicon, 30m2 Includes a surface area of ​​less than / g, a diameter of 0.3 or greater, and an average Coulomb efficiency of 0.9969 or greater, for example, a carbon scaffold with a Z of less than 10, a microporosity of more than 80%, 30-60% silicon, 30m 2 Carbon scaffolds with a surface area of ​​less than / g, a diameter of 0.3 or greater, and an average Coulomb efficiency of 0.9970 or greater, e.g., a Z of less than 10, and a microporosity of over 80%, containing 30-60% silicon, and 30m 2 Carbon scaffolds with a surface area of ​​less than / g, a diameter of 0.3 or greater, and an average Coulomb efficiency of 0.9975 or greater, e.g., a Z of less than 10, and a microporosity of over 80%, containing 30-60% silicon, and 30m 2 Carbon scaffolds with a surface area of ​​less than / g, a diameter of 0.3 or greater, and an average Coulomb efficiency of 0.9980 or greater, e.g., a Z of less than 10, and a microporosity of over 80%, containing 30-60% silicon, and 30m 2 Carbon scaffolds with a surface area of ​​less than / g, a diameter of 0.3 or greater, and an average Coulomb efficiency of 0.9985 or greater, e.g., a Z of less than 10, and a microporosity of over 80%, containing 30-60% silicon, and 30m 2 Carbon scaffolds with a surface area of ​​less than / g, a diameter of 0.3 or greater, and an average Coulomb efficiency of 0.9990 or greater, e.g., a Z of less than 10, and a microporosity of over 80%, containing 30-60% silicon, and 30m 2 Carbon scaffolds with a surface area of ​​less than / g, a diameter of 0.3 or greater, and an average Coulomb efficiency of 0.9995 or greater, e.g., a Z of less than 10, and a microporosity of over 80%, containing 30-60% silicon, and 30m 2 Examples include a surface area of ​​less than / g, a diameter of 0.3 or greater, and an average Coulomb efficiency of 0.9999 or greater.

[0204] Example 4. Particle size distribution of various carbon scaffold materials. The particle size distribution of various carbon scaffold materials was measured using a laser diffraction particle size analyzer known in the art. In particular, the data for Dv1, Dv10, Dv50, Dv90, and Dv100 are shown in Table 7.

[0205] Physical properties of various carbon scaffold materials [Table 7]

[0206] Example 5. Lithium-silicon battery comprising an anode containing a silicon and carbon-containing composite, which are Group 14 elements. A novel composite containing silicon and carbon, which are Group 14 elements, has utility for dramatically improving the performance of a lithium-silicon battery. As is known in the art, lithium-silicon batteries include various other properties, as described in this example.

[0207] The lithium-silicon battery described above includes an anode containing a silicon-carbon composite, which is a Group 14 element. The dry weight concentration of the silicon-carbon composite in the anode can vary, for example, 1% to 90%, 5% to 95%, 10% to 70%, etc. In certain embodiments, the dry weight concentration of the silicon-carbon composite in the anode is 5% to 25%, 25% to 35%, 35% to 50%, 50% to 70%, or greater than 70%.

[0208] The above anode may further contain other components, including graphite, conductive carbon additives, binders, and combinations thereof.

[0209] In some embodiments, the lithium-silicon battery includes an anode containing graphite, or a combination thereof. Typical liquid graphite in this regard includes, but is not particularly limited, natural graphite, synthetic graphite, nanographite, or a combination thereof. The dry weight concentration of graphite in the anode can vary, for example, 5% to 95%, 10% to 70%, 20% to 60%, 30% to 50%, etc. In certain embodiments, the lithium-silicon battery includes an anode that does not contain graphite.

[0210] In a preferred embodiment, the lithium-silicon battery includes an anode containing a conductive carbon additive, or a combination thereof. Typical conductive carbon additives are not particularly limited, but include, for example, carbon black, conductive carbon black, superconductive carbon black, extraconductive carbon black, ultraconductive carbon black, Super C, Super P, Super[C45 or C65], Ketjenblack carbon, acetylene black, fullerene, graphene, carbon fiber, carbon nanofiber, carbon nanotube, or a combination thereof. The dry weight concentration of the conductive carbon additive in the anode may vary, for example, 0.1% to 20%, 1% to 10%, 2% to 8%, 3% to 6%, etc. In certain embodiments, for example, when the anode does not contain graphite, the dry weight concentration of the conductive carbon additive may be in the range of 5% to 20%, such as 10% to 20%, 14% to 16%, and so on.

[0211] In preferred embodiments, the lithium-silicon battery includes an anode containing a binder, or a combination thereof. Typical binders are not particularly limited, but include, for example, polyvinylidene fluoride (PVDF), styrene-butadiene rubber (SBR), sodium carboxymethylcellulose (Na-CMC), polyacrylonitrile (PAN), polyacrylic acid latex, polyacrylic acid (PAA), polyvinyl alcohol (PVA), polyethylene glycol (PEG), polyamide-imide (PAI), polyimide (PI), and combinations thereof. In specific embodiments, the binder may contain lithium ions as counterions. The dry weight concentration of the binder in the anode can vary, for example, 0.1% to 20%, 1% to 10%, 2% to 8%, 3% to 6%, and so on. In certain embodiments, for example, when the anode does not contain graphite, the dry weight concentration of the binder may be in the range of 5% to 20%, such as 10% to 20%, 14% to 16%, and so on.

[0212] The anode of a lithium-silicon battery comprises a composite containing silicon and carbon, which are Group 14 elements, and further comprises porosity in a dry state. The porosity of the dry anode can vary, for example, from 10% to 90%, 20% to 80%, 30% to 70%, or 40% to 60%. In a particular preferred embodiment, the porosity of the dry anode is 30% to 50%. In a particular preferred embodiment, the porosity of the dry anode is 10% to 50%.

[0213] A lithium-silicon battery includes an anode containing a silicon and carbon-containing composite, which are Group 14 elements, and further includes a cathode. Typical cathodes are not particularly limited, but include, for example, lithium cobalt oxide (LiCoO2) (LCO), lithium manganese oxide (LiMn2O4) (LMO), lithium iron phosphate (LiFePo4) (LFP), lithium nickel cobalt aluminum oxide (LiNiCoAlO2) (NCA), lithium titanate (Li2TiO3) (LTO), or lithium nickel manganese cobalt oxide (LiNi x Mn y Co z Examples include O2)(NMC, where x+y+z=1 and x:y:z=3:3:3(NMC333), 4:3:3(NMC433), 5:3:2(NMC532), 6:1:1(NMC611), 6:2:2(NMC622), 8:1:1(NMC811), etc.). In a particular preferred embodiment, the cathode is NMC811.

[0214] Lithium-silicon batteries include a ratio known as the N / P ratio, which represents the capacity ratio between the anode and cathode electrodes in the battery. The N / P ratio is important for determining the energy density of lithium-silicon batteries. Although not theoretically bound, a lower N / P ratio gives less excess anode, thereby giving a higher energy density to lithium-silicon batteries. The average discharge potential of silicon-carbon anodes is higher than that of graphite anodes. Although not theoretically bound, the presence of φ in the anode reduces the excess anode needed to avoid plating of the battery. Therefore, although not theoretically bound, novel anode materials containing φ greater than 0 (e.g., φ greater than 0.15, φ greater than 0.2, φ greater than 0.25, φ greater than 0.3), as described herein, further reduce the N / P ratio, thereby giving a higher energy density to lithium-silicon batteries. In certain embodiments, the N / P ratio is greater than 1.1, for example, greater than 1.2, greater than 1.3, greater than 1.4, greater than 1.5, greater than 2.0, etc. In certain preferred embodiments, the N / P ratio is 2.0 or less, for example, 1.5 or less, 1.4 or less, 1.3 or less, 1.2 or less, 1.1 or less, 1.0 or less, 0.9 or less, 0.8 or less, etc.

[0215] Lithium-silicon batteries contain an electrolyte, which comprises various components including a solvent, solvent additives, and electrolyte ions. Typical electrolyte components are not particularly limited, but include, for example, ethylene carbonate (EC), diethylene carbonate (DEC), propylene carbonate (PC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), ethyl propyl ether (EPE), fluorinated cyclic carbonate (F-AEC), fluorinated linear carbonate (F-EMC), dimethylacrylamide (DMAA), succinic anhydride (SA), tris(trimethylsilyl) borate (TTMB), tris(trimethylsilyl) phosphate (TTSP), 1,3-propanesultone (PS), fluorinated ether (F-EPE), fluoroethylene carbonate (FEC), performance-enhancing organosilicon electrolyte materials (e.g., OS3), vinylene carbonate (VC), LiPF6, LiBF4, LiBOB, LiTFSI, LiFSI, LiClO4, and combinations thereof. In certain embodiments, the concentration of the electrolyte salt is greater than 1.0 M, for example, greater than 1.2 M, greater than 1.3 M, greater than 1.4 M, greater than 1.5 M, greater than 2.0 M. In certain preferred embodiments, the concentration of the electrolyte salt is less than 2.0 M, for example, less than 1.5 M, less than 1.4 M, less than 1.3 M, less than 1.2 M, less than 1.1 M, less than 1.0 M, less than 0.9 M.

[0216] Lithium-silicon batteries containing silicon and carbon-containing composites, which are Group 14 elements, include a separator that maintains the separation of the anode and cathode. The separator may be made from a single or multi-layer polymer material, or it may be coated with aramid, ceramic, or fluoride material. Typical separator materials are not particularly limited, but include, for example, nonwoven fabrics (cotton, nylon, polyester, glass), polymer films (polyethylene, polypropylene, poly(tetrafluoroethylene), polyvinyl chloride), ceramics, and natural products (rubber, asbestos, wood), etc. In certain preferred embodiments, the separator includes a polymer, and typical polymers are not particularly limited, but include, for example, polyolefin-based materials having a semicrystalline structure, polyethylene, polypropylene, graft polymers (including micropore-grafted polymethyl methacrylate and siloxane-grafted polyethylene), polyvinylidene fluoride (PVDF) nanofiber webs, and polytriphenylamine (PTPA), etc.

[0217] Lithium-silicon batteries containing silicon and carbon-containing composites, which are Group 14 elements, cycle between the lower and upper limits of the lithium-silicon battery's operating voltage window during battery use. Although not bound by theory, a lower operating voltage window results in a higher energy density for lithium-silicon batteries. Therefore, although not bound by theory, novel anode materials disclosed herein, including φ greater than 0 (e.g., φ greater than 0.15, φ greater than 0.2, φ greater than 0.25, φ greater than 0.3), lower the lower limit of the voltage window, thereby increasing the energy density of lithium-silicon batteries. In certain embodiments, the lower limit of the voltage window is 3.0V or less, e.g., 2.9V or less, e.g., 2.8V or less, e.g., 2.7V or less, e.g., 2.6V or less, e.g., 2.5V or less, e.g., 2.4V or less, e.g., 2.3V or less. The upper limit of the voltage window during a lithium-silicon battery cycle can vary, for example, 4.0V or higher, such as 4.0V, 4.1V, 4.2V, 4.3V, 4.4V, 4.5V, 4.6V, 4.7V, 4.8V, 4.9V, or 5.0V.

[0218] Example 6. Passivation of silicon-carbon composite materials produced by CVI using various oxygen-containing gases. Carbon scaffold 10 was used as the porous carbon scaffold, and the CVI process described in Example 1 was generally carried out. Exceptionally, in this example, silicon-carbon composite materials were produced by passivating various samples in various ways as the final step in the production of the silicon-carbon composite. In each case, after the completion of the CVI process, the process gas was switched to nitrogen gas before reaching the desired passivation temperature, where the temperature was maintained at the desired passivation temperature, and then the process gas was switched back to the passivation gas. After passivation, the temperature was lowered to below 100°C, and the material was removed for characterization. An overview of the passivation method and the properties of the produced silicon-carbon composite materials are shown in Table 8 below.

[0219] Passivation of silicon-carbon composite material by Example 6 [Table 8]

[0220] The use of air as a passivation agent (silicon-carbon composite sample #22) yielded favorable conditions. No excessive sample heating (thermal runaway) was observed. Therefore, these conditions represent a safe, industrially important, and scalable approach for the production of silicon-carbon composites. In contrast, a comparative sample of silicon-carbon composite produced by a CVI reaction using the same carbon scaffold showed a low mass increase (29%) and low silicon content (25%), and was passivated with air at a relatively low temperature (26°C), with a surface area of ​​730 m². 2 The result was / g. In particular, thermal runaway was observed in this sample.

[0221] Table 8 shows that various alternative oxygen-containing gases, such as water vapor, ethanol vapor, or carbon dioxide, can also be used without problems as passivation gases at the temperatures listed in Table 8. Furthermore, the silicon content and Z of the silicon-carbon composite can be measured by TGA, and these values ​​are shown in Table 8. Tests of the silicon-carbon composite material were also conducted in half-cell coin cells. These data are shown in Table 9.

[0222] Electrochemical evaluation of various silicon-carbon composite samples prepared according to Example 5. [Table 9]

[0223] No overheating was observed in any of the various passivation approaches used in Table 9. As can be seen, the conditions of 200°C and water vapor were found to be suitable as passivation gases for silicon-carbon composite samples produced by CVI. Similarly, the conditions of 200°C and ethanol gas were also found to be suitable as passivation gases for silicon-carbon composite samples produced by CVI. Although not bound by theory, it is expected that passivation in oxygen-containing gases with larger molecular sizes than oxygen gas will not be easy due to the additional diffusion limit imposed by silicon produced by CVI. Therefore, it is a surprising and unexpected result that such alcohols, such as denatured alcohol, are suitable for passivating silicon produced by CVI, i.e., silicon located in the pores of porous carbon scaffolds. In further embodiments, the oxygen-containing passivation gas may be an alcohol, and is not particularly limited, but may include, for example, methanol, ethanol, denatured alcohol, propanol, butanol, isopropyl alcohol, dimethyl carbonate, ethylene carbonate, and combinations thereof.

[0224] Furthermore, the conditions of 400°C and carbon dioxide were also found to be suitable as passivation gases for silicon-carbon composite samples produced by CVI. In this method, passivation was carried out under a temperature regime similar to that of the CVI process. In some embodiments, passivation and CVI treatment can be performed alternately, thus layering of oxygen components in silicon impregnated within porous carbon. In this method, the characteristic silicon size is further reduced compared to when passivation is performed after the completion of the CVI treatment. Although not theoretically bound, the layering of oxygen in silicon produced by CVI, located within carbon pores, offers advantages such as improved cycle stability and reduced expansion during lithiation when the material is used as an anode for lithium-ion batteries.

[0225] For this purpose, silicon-carbon composite samples were prepared in the same manner as silicon-carbon composite #25, with the exception that the reaction temperature was maintained at 440°C, and the gases introduced into the reactor were silane (to achieve CVI) and CO2 (to achieve passivation), with three intervals in which each of the CVI treatment and passivation was introduced alternately at three independent and equally spaced intervals. This resulted in three layers of silicon-oxygen passivated surfaces on silicon, which are represented as silicon-carbon composite #26 in Tables 8 and 9. Measurement by TGA showed that this sample had a substantially lower silicon content compared to the overall mass increase from three intermittent CVI and passivation treatments. This difference is due to the increased oxygen content in this sample compared to the other samples shown in Table 8. Importantly, the average Coulomb efficiency of this sample was high at 0.9983, in contrast to the other comparisons shown in Table 9.

[0226] In some embodiments, silicon-carbon composite materials are manufactured by maintaining the temperature of a porous carbon scaffold at 350°C to 550°C and alternating the introduction of process gases, a silicon-containing gas and an oxygen-containing gas, for a total of two intervals each. In some embodiments, the alternating introduction of the silicon-containing gas and the oxygen-containing gas process can be carried out for a total of three intervals each, or four intervals each, or five intervals each, or 5 to 10 intervals each, or more than 10 intervals each.

[0227] Example 7. Passivation of silicon-carbon composite material produced by CVI using oxygen-free gas. The silicon-carbon composite material was produced using carbon scaffold 10 as the porous carbon scaffold, and the CVI process described in Example 1 was generally carried out. However, in this example, as an exception, various samples were produced by passivating them using an oxygen-free gas in the final step of silicon-carbon composite production. In this example, the oxygen-free gas was a hydrocarbon, i.e., propylene gas. In this example, the CVI reaction temperature was 440°C, and passivation using propylene was performed by introducing propylene after the completion of the CVI process, and the process temperature was cooled from the initial 440°C for about 60 minutes to perform passivation. Therefore, the passivation temperature was less than 440°C. Details of this sample are shown in Table 10, and the electrochemical properties are shown in Table 11.

[0228] Passivation of silicon-carbon composite materials [Table 10]

[0229] Electrochemical evaluation of various silicon-carbon composite samples prepared according to Example 6. [Table 11]

[0230] While not bound by theory, the use of propylene as a passivator not only results in passivation of the silicon surface but also provides a terminal carbon coating on the silicon-carbon composite. While not bound by theory, this provides further advantages such as improved electrical conductivity and improved stability due to reduced reactivity of the terminal carbon coating layer. Similarly, the silicon-carbon composite thus produced offers further advantages when used as an anode material for lithium-ion batteries (though not limited to, for example, improved rated capacity, improved cycle life at room temperature, improved cycle life at high temperatures such as 45°C or 60°C, and / or improved calendar life).

[0231] In some embodiments, the size of silicon-carbon composite particles is reduced after CVI treatment and before passivation. In other embodiments, the size of silicon-carbon composite particles is reduced after passivation.

[0232] Example 8. Hydrosilylation passivation of silicon-carbon composite materials produced by CVI using acetylene. The production of silicon-carbon composite materials using the following CVI and passivation can be achieved by hydrosilylation passivation. The temperature can be in the range of 100°C to 500°C, for example 120°C, 150°C, 170°C, 180°C, 200°C, 250°C, 300°C, 350°C, 400°C, 450°C, etc. In one preferred embodiment, the temperature is 170°C or 190°C. The atmospheric pressure can be atmospheric pressure. In some embodiments, the atmospheric pressure can be lower than atmospheric pressure. In some embodiments, the atmospheric pressure can be higher than atmospheric pressure. Although not bound by theory, acetylene undergoes the self-terminal hydrosilylation reaction with the Si-H surface groups as shown below. Si-H + R1=R2 → Si-R1H-R2 [In the formula, R1 and R2 correspond to an alkane, alkene, or alkyne, as is well known in the art.] Thus, alkyl(ethyl) terminators are formed, which ultimately do not undergo further oxidation even when exposed to air. This particular hydrosilylation passivation reaction is advantageous because it does not release byproducts or confer oxygen components, thereby potentially improving the electrochemical performance of the anode to mitigate the formation of irreversible Li-O byproducts or parasitic side reactions with other electrolytes in Li-ion batteries.

[0233] While not bound by theory, the hydrosilylation passivation of silicon-carbon composites results in carbon scaffolds and nano-sized silicon domains within the pores of porous carbon, where the silicon surface contains Si-R bonds (where R represents an organic functional group comprising a combination of carbon, oxygen, nitrogen, or hydrogen, and typical R species are alkanes, alkenes, or alkynes). In some embodiments, R includes halogen elements, such as bromine, fluorine, chlorine, or iodine.

[0234] Table 12 lists various samples prepared using hydrosilylation passivation according to Example 8.

[0235] Hydrosilylated passivation of a silicon-carbon composite material prepared according to Example 8. [Table 12] Silicon-carbon composite #27 represents the control, which is air-passivated rather than hydrosilylated.

[0236] The electrochemical characterization of the selected samples was evaluated (Table 13). For both Z and φ, the trends and ranges in the chemical vapor-passivated and air-passivated samples followed similar behavior as shown in the above examples (e.g., Examples 1-3).

[0237] Electrochemical characterization of hydrosilylated passivation of silicon-carbon composite materials according to Example 8. [Table 13]

[0238] Example 9. Passivation of silicon-carbon composite material produced by CVI using gasified liquid. In certain embodiments, the alkene and / or alkyne passivator is liquid under standard temperature and pressure conditions. Following the deposition of silane-derived silicon on a porous substrate, the material is cooled and held at 100-500°C (e.g., 120°C, 150°C, 170°C, 180°C, 200°C, 250°C, 300°C, 350°C, 400°C, 450°C, etc.). In one preferred embodiment, the temperature is 170°C. A certain amount of time is allowed to pass until the temperature reaches equilibrium (about 30 minutes). At this point, the gas flow is stopped and the reactor is evacuated. Next, the reactor is backfilled to the desired pressure with a bubbler / dewar containing a liquid alkene having a boiling point lower than the reactor temperature (e.g., allyl glycidyl ether, boiling point 154°C), and allowed to remain in the gas phase for the duration of the reaction. The reactor is sealed and left at the temperature for 1 to 24 hours to promote the hydrosilylation passivation reaction. In another embodiment, the vacuum step can be omitted, and instead, the inert gas flow can be bypassed through a bubbler / dewar containing the alkene / alkyne liquid species, allowing the vapor to permeate the gas flow and be introduced into the reactor for the above time, thus maintaining atmospheric pressure during the reaction.

[0239] In another embodiment, the hydrosilylation reaction is carried out in a suspension. Here, the silicon-carbon composite is transferred from the reactor to an inert gas environment (e.g., argon, nitrogen, helium) and dispersed in an aprotic solvent (e.g., THF or toluene) with or without stirring. An alkene / alkyne species (e.g., allyl glycidyl ether) is added to the suspension, followed by a catalyst (e.g., platinum(0)-1,3-divinyl-1,1,3,3,-tetramethyldisiloxane complex). The suspension is gently heated (e.g., 30-50°C) and reacted for a set period of time (e.g., 1-24 hours). The passivated silicon-carbon composite is then recovered using conventional methods (e.g., centrifugation, filtration, spray drying, etc.).

[0240] Example 10. Passivation of silicon-carbon composite material produced by CVI using a combination of passivating agents. In further embodiments, combinations of different alkene / alkyne species are used for simultaneous passivation to achieve a combination of physical properties and / or performance characteristics. Following the deposition of silicon derived from silane onto a porous substrate, the material is cooled to 170°C under an inert gas and held therein. A certain amount of time is allowed (about 30 minutes) until the temperature reaches equilibrium. At this point, the gas flow is stopped and the reactor is evacuated. The reactor is backfilled to the desired pressure with a bubbler / dewar containing a mixture of two or more liquid alkenes having a boiling point lower than the reactor temperature (e.g., allyl glycidyl ether and allyl oxy (polyethylene oxide)), and kept in the gas phase for the duration of the reaction. The reactor is sealed and left at the temperature for 3 hours to promote the hydrosilylation passivation reaction.

[0241] In preferred embodiments, the temperature during hydrosilylation passivation is 100°C to 220°C, preferably 160°C to 190°C. In preferred embodiments, the atmospheric pressure during hydrosilylation passivation is 0.001 tor to 800 tor, preferably 500 to 760 tor. Typical species used as hydrosilylation passivating agents include acetylene, propylene, ethylene, butene, allyloxyethanol, diallyl carbonate, allyl methyl carbonate, allyl ethyl carbonate, allyl glycidyl ether, allyloxy(polyethylene oxide) methyl ether, and allyloxytrimethylsilane (preferred species: acetylene, allyl glycidyl ether, allyl ethyl carbonate, and allyloxy(polyethylene oxide)). The preferred retention time during hydrosilylation passivation is 0.5 to 12 hours, more preferably 1 to 6 hours. In certain embodiments, a catalyst may be used to reduce the reaction temperature and time of hydrosilylation passivation. In such embodiments, typical catalysts include platinum (Karstedt's catalyst), ultraviolet light (wavelength approximately 365 nm), radical initiators (e.g., 2,2-azobisisobutyronitrile, benzoyl peroxide, or borane), and combinations thereof.

[0242] Example 11. Chemical vapor passivation (CVP) of silicon-carbon composite materials. This example describes a novel method for in situ passivation of silicon-carbon composite materials, which we will refer to here as chemical vapor passivation (CVP). According to the CVP method, silicon-carbon composite materials (e.g., silicon-carbon composite materials produced by CVI to produce nano-sized amorphous silicon in porous carbon scaffolds) are subsequently passivated at high temperatures in the presence of hydrocarbon gases. The CVP temperature can vary, for example, 400°C to 1000°C, 400°C to 500°C, 500°C to 600°C, 600°C to 700°C, 700°C to 800°C, 800°C to 900°C, 900°C to 1000°C, 400°C to 450°C, 450°C to 500°C, 500°C to 550°C, 550°C to 600°C, 600°C to 650°C, 650°C to 700°C, 700°C to 750°C, 750°C to 800°C, 800°C to 850°C, 850°C to 900°C, 900°C to 950°C, 950°C to 1000°C, and so on. In some embodiments, the CVI temperature is in the range of 400°C to 600°C, 500°C to 700°C, 600°C to 800°C, 700°C to 900°C, or 800°C to 1000°C. In some preferred embodiments, the temperature is in the range of 300°C to 700°C. The gas used in the CVP process may be hydrocarbons (e.g., acetylene, ethylene, propylene, propane, ethane, methane, butane, butylene, or combinations thereof). In some preferred embodiments, acetylene is used. The atmospheric pressure may be atmospheric pressure. In some embodiments, the atmospheric pressure may be less than atmospheric pressure. In some embodiments, the atmospheric pressure may be greater than atmospheric pressure. During the CVP process, the hydrocarbon gas decomposes on the surface of the material, forming an amorphous carbon coating (hence C x H Y => This reaction produces C + H2. This particular passivation reaction is advantageous because the thickness of the carbon layer can be controlled by adjusting the reaction temperature and time, and the carbon layer itself can impart electrical conductivity to the host silicon-carbon composite.

[0243] While not bound by theory, the CVP of silicon-carbon composites results in a material comprising a carbon scaffold, nano-sized silicon domains within the pores of porous carbon (where the silicon surface contains Si-H bonds), and a carbonaceous layer that at least partially covers the silicon domains.

[0244] According to this embodiment, various silicon-carbon composite samples are prepared, generally following the method described herein, with passivation achieved by CVP. These samples are shown in Table 14. The carbon scaffold used was carbon scaffold 10, or other similar porous material. The CVP temperature was in the range of 300°C to 700°C. Alternatively, the CVP temperature may be 700°C to 1000°C. The oxygen content of the selected samples was measured; the oxygen content was in the range of 0.6 to 2.9%. With respect to both Z and φ, the trends and ranges in the chemical vapor-passivated and air-passivated samples followed similar behavior as shown in the above examples (e.g., Examples 1 to 3).

[0245] CVP of silicon-carbon composite material according to Example 11. [Table 14]

[0246] Description of the Embodiment Embodiment 1. A method for producing passivated silicon-carbon composite particles, the following: a. To provide a carbon scaffold having a pore volume containing more than 70% microporosity; b. Heating porous carbon scaffold particles to 350°C to 550°C in the presence of silane gas; c. Lowering the temperature to below 200°C in the presence of nitrogen gas; and d. Adding an oxygen-containing gas. A manufacturing method that includes this.

[0247] Embodiment 2. A method for producing passivated silicon-carbon composite particles, the following: a. To provide a carbon scaffold having a pore volume containing more than 70% microporosity; b. Heating porous carbon scaffold particles to 350°C to 550°C in the presence of silane gas; c. Lowering the temperature to below 200°C in the presence of nitrogen gas; d. Adding oxygen-containing gas; and e. Here, the passivated silicon-carbon composite is as follows: i. Includes Z less than 10, where Z is Z is calculated as Z = 1.875 × [(M1100 - M) / M1100] × 100%, (wherein, when the silicon-carbon composite is heated in air from approximately 25°C to approximately 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C; these masses are determined by thermogravimetric analysis.) A manufacturing method that includes this.

[0248] Embodiment 3. A method for producing passivated silicon-carbon composite particles, the following: a. To provide a carbon scaffold having a pore volume containing more than 70% microporosity; b. Heating porous carbon scaffold particles to 350°C to 550°C in the presence of silane gas; c. Lowering the temperature to below 200°C in the presence of nitrogen gas; d. Adding oxygen-containing gas; and e. Here, the passivated silicon-carbon composite is as follows: i. Z less than 10, where Z is, Z = 1.875 × [(M1100-M) / M1100] × 100%, (wherein, when the silicon-carbon composite is heated in air from approximately 25°C to approximately 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C, and these masses are determined by thermogravimetric analysis.) is used for calculation; and ii. 0.1 or greater φ, where said φ is φ is calculated from φ = (maximum peak height of dQ / dV in regime I) / (maximum peak height of dQ / dV in regime III), (wherein dQ / dV is measured in a half-cell coin cell, with regime I being 0.8V to 0.4V and regime III being 0.15V to 0V). Includes passivated silicon-carbon composite, A manufacturing method that includes this.

[0249] Embodiment 4. A method for producing passivated silicon-carbon composite particles, the following: a. To provide a carbon scaffold having a pore volume containing more than 70% microporosity; b. Heating porous carbon scaffold particles to 350°C to 550°C in the presence of silane gas; c. Lowering the temperature to below 200°C in the presence of nitrogen gas; d. Adding oxygen-containing gas; and e. Here, the passivated silicon-carbon composite is as follows: i. Silicone content of 30% to 60% by weight; ii. 30m 2 Surface area less than / g; iii. Z less than 10, where Z is, Z = 1.875 × [(M1100-M) / M1100] × 100%, (wherein, when the silicon-carbon composite is heated in air from approximately 25°C to approximately 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C, and these masses are determined by thermogravimetric analysis.) is used for calculation; and iv.0.1 includes φ greater than or equal to, where φ is, φ is calculated from φ = (maximum peak height of dQ / dV in regime I) / (maximum peak height of dQ / dV in regime III), (wherein dQ / dV is measured in a half-cell coin cell, with regime I being 0.8V to 0.4V and regime III being 0.15V to 0V). A manufacturing method that includes this.

[0250] Embodiment 5. A method for producing passivated silicon-carbon composite particles, the following: a. To provide a carbon scaffold having a pore volume containing more than 70% microporosity; b. Heating porous carbon scaffold particles to 350°C to 550°C in the presence of silane gas; c. Adjust the temperature to 400°C or below in the presence of nitrogen gas; and d. Adding an oxygen-containing gas. A manufacturing method that includes this.

[0251] Embodiment 6. A method for producing passivated silicon-carbon composite particles, the following: a. To provide a carbon scaffold having a pore volume containing more than 70% microporosity; b. Heating porous carbon scaffold particles to 350°C to 550°C in the presence of silane gas; c. Adjust the temperature to below 400°C in the presence of nitrogen gas; d. Adding oxygen-containing gas; and e. Here, the passivated silicon-carbon composite is as follows: i. Includes Z less than 10, where Z is Z = 1.875 × [(M1100 - M) / M1100] × 100%, (wherein, when the silicon-carbon composite is heated in air from approximately 25°C to approximately 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C. These masses are determined by thermogravimetric analysis.) A manufacturing method that includes this.

[0252] Embodiment 7. A method for producing passivated silicon-carbon composite particles, the following: a. To provide a carbon scaffold having a pore volume containing more than 70% microporosity; b. Heating porous carbon scaffold particles to 350°C to 550°C in the presence of silane gas; c. Adjust the temperature to 400°C or below in the presence of nitrogen gas; and d. Adding oxygen-containing gas; and e. Here, the passivated silicon-carbon composite is as follows: i. Z less than 10, where Z is, Z = 1.875 × [(M1100-M) / M1100] × 100%, (wherein, when the silicon-carbon composite is heated in air from approximately 25°C to approximately 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C, and these masses are determined by thermogravimetric analysis.) is used for calculation; and ii.0.1 includes φ greater than or equal to, where said φ is, φ is calculated from φ = (maximum peak height of dQ / dV in regime I) / (maximum peak height of dQ / dV in regime III), (wherein dQ / dV is measured in a half-cell coin cell, with regime I being 0.8V to 0.4V and regime III being 0.15V to 0V). A manufacturing method that includes this.

[0253] Embodiment 8. A method for producing passivated silicon-carbon composite particles, the following: a. To provide a carbon scaffold having a pore volume containing more than 70% microporosity; b. Heating porous carbon scaffold particles to 350°C to 550°C in the presence of silane gas; c. Adjust the temperature to below 400°C in the presence of nitrogen gas; d. Adding oxygen-containing gas; and e. Here, the passivated silicon-carbon composite is as follows: i. Silicone content of 30% to 60% by weight; ii. 30m 2 Surface area less than / g; iii. Z less than 10, where Z is, Z = 1.875 × [(M1100-M) / M1100] × 100%, (wherein, when the silicon-carbon composite is heated in air from approximately 25°C to approximately 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C, and these masses are determined by thermogravimetric analysis.) is used for calculation; and iv.0.1 includes φ greater than or equal to, where φ is, φ is calculated from φ = (maximum peak height of dQ / dV in regime I) / (maximum peak height of dQ / dV in regime III), (wherein dQ / dV is measured in a half-cell coin cell, with regime I being 0.8V to 0.4V and regime III being 0.15V to 0V). A manufacturing method that includes this.

[0254] Embodiment 9: A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 1 to 8, comprising a pore volume having more than 80% microporosity.

[0255] Embodiment 10: A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 1 to 9, comprising a pore volume having more than 90% microporosity.

[0256] Embodiment 1: A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 1 to 10, comprising a pore volume having more than 1.95% microporosity.

[0257] Embodiment 12. A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 1 to 11, comprising heating porous carbon scaffold particles to 400°C to 525°C in the presence of silane gas.

[0258] Embodiment 13. A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 1 to 12, wherein the silicon-carbon composite contains a silicon content of 40% to 60%.

[0259] Embodiment 14. A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 1 to 13, wherein the silicon-carbon composite contains a Z of less than 5.

[0260] Embodiment 15. A silicon-carbon composite is 10 m 2 A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 1 to 14, including a surface area of ​​less than / g.

[0261] Embodiment 16. A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 1 to 15, wherein the silicon-carbon composite contains a φ of 0.2 or more, where the φ is φ is calculated from φ = (maximum peak height of dQ / dV in regime I) / (maximum peak height of dQ / dV in regime III), (wherein dQ / dV is measured in a half-cell coin cell, with regime I being 0.8V to 0.4V and regime III being 0.15V to 0V).

[0262] Embodiment 17. A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 1 to 16, wherein the silicon-carbon composite contains a φ of 0.3 or more, where the φ is φ is calculated from φ = (maximum peak height of dQ / dV in regime I) / (maximum peak height of dQ / dV in regime III), (wherein dQ / dV is measured in a half-cell coin cell, with regime I being 0.8V to 0.4V and regime III being 0.15V to 0V).

[0263] Embodiment 18. A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 1 to 17, wherein the silicon-carbon composite contains Dv50 particles ranging from 5 nm to 20 microns in size.

[0264] Embodiment 19. A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 1 to 18, wherein the silicon-carbon composite has a capacity of more than 900 mA / g.

[0265] Embodiment 20. A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 1 to 19, wherein the silicon-carbon composite has a capacity greater than 1300 mA / g.

[0266] Embodiment 21. A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 1 to 20, wherein the silicon-carbon composite has a capacity of more than 1600 mA / g.

[0267] Embodiment 22. A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 1 to 21, wherein the oxygen-containing gas contains carbon dioxide.

[0268] Embodiment 23. A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 1 to 21, wherein the oxygen-containing gas contains ethanol.

[0269] Embodiment 24. A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 1 to 21, wherein the oxygen-containing gas comprises dimethyl carbonate, ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, or vinylene carbonate, or a combination thereof.

[0270] Embodiment 25. A method for producing passivated silicon-carbon composite particles, the following: a. To provide a carbon scaffold having a pore volume containing more than 70% microporosity; b. Heating porous carbon scaffold particles to 350°C to 550°C in the presence of silane gas; and c. Alternating between silane gas and carbon dioxide gas as the process gas. A manufacturing method that includes this.

[0271] Embodiment 26. A method for producing passivated silicon-carbon composite particles, the following: a. To provide a carbon scaffold having a pore volume containing more than 70% microporosity; b. Heating porous carbon scaffold particles to 350°C to 550°C in the presence of silane gas; c. Alternating between silane gas and carbon dioxide gas as the process gas; and d. Here, the passivated silicon-carbon composite is as follows: i. Includes Z less than 10, where Z is calculated as Z = 1.875 × [(M1100-M) / M1100] × 100%, (wherein, when the silicon-carbon composite is heated in air from approximately 25°C to approximately 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C, and these masses are determined by thermogravimetric analysis.) A manufacturing method that includes this.

[0272] Embodiment 27. A method for producing passivated silicon-carbon composite particles, the following: a. To provide a carbon scaffold having a pore volume containing more than 70% microporosity; b. Heating porous carbon scaffold particles to 350°C to 550°C in the presence of silane gas; c. Alternating between silane gas and carbon dioxide gas as the process gas; and d. Here, the passivated silicon-carbon composite is as follows: i. Z less than 10, where Z is, Z = 1.875 × [(M1100-M) / M1100] × 100%, (wherein, when the silicon-carbon composite is heated in air from approximately 25°C to approximately 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C, and these masses are determined by thermogravimetric analysis.) is used for calculation; and ii.0.1 includes φ greater than or equal to, where said φ is, φ is calculated from φ = (maximum peak height of dQ / dV in regime I) / (maximum peak height of dQ / dV in regime III), (wherein dQ / dV is measured in a half-cell coin cell, with regime I being 0.8V to 0.4V and regime III being 0.15V to 0V). A manufacturing method that includes this.

[0273] Embodiment 28. A method for producing passivated silicon-carbon composite particles, the following: a. To provide a carbon scaffold having a pore volume containing more than 70% microporosity; b. Heating porous carbon scaffold particles to 350°C to 550°C in the presence of silane gas; c. Alternating between silane gas and carbon dioxide gas as the process gas; and d. Here, the passivated silicon-carbon composite is as follows: i. Silicone content of 30% to 60% by weight; ii. 30m 2 Surface area less than / g; iii. Z less than 10, where Z is, Z = 1.875 × [(M1100-M) / M1100] × 100%, (wherein, when the silicon-carbon composite is heated in air from approximately 25°C to approximately 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C, and these masses are determined by thermogravimetric analysis.) is used for calculation; and iv.0.1 includes φ greater than or equal to, where φ is, φ is calculated from φ = (maximum peak height of dQ / dV in regime I) / (maximum peak height of dQ / dV in regime III), (wherein dQ / dV is measured in a half-cell coin cell, with regime I being 0.8V to 0.4V and regime III being 0.15V to 0V). A manufacturing method that includes this.

[0274] A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 25 to 28, comprising a pore volume having more than 9.80% microporosity.

[0275] Embodiment 3: A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 25 to 28, comprising a pore volume having more than 90% microporosity.

[0276] Embodiment 3: A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 25 to 28, comprising a pore volume having more than 1.95% microporosity.

[0277] Embodiment 32. A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 25 to 28, wherein the silicon-carbon composite contains a silicon content of 40% to 60%.

[0278] Embodiment 33. A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 25 to 28, wherein the silicon-carbon composite contains Z less than 5.

[0279] Embodiment 34. A silicon-carbon composite is 10 m 2 A method for producing passivated silicon-carbon composite particles according to any one of embodiments 25 to 28, including a surface area of ​​less than 1 / g.

[0280] Embodiment 35. A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 25 to 28, wherein the silicon-carbon composite contains a φ of 0.2 or more, where the φ is φ is calculated from φ = (maximum peak height of dQ / dV in regime I) / (maximum peak height of dQ / dV in regime III), (wherein dQ / dV is measured in a half-cell coin cell, with regime I being 0.8V to 0.4V and regime III being 0.15V to 0V).

[0281] Embodiment 36. A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 25 to 28, wherein the silicon-carbon composite contains a φ of 0.3 or more. Here, the φ is φ is calculated from φ = (maximum peak height of dQ / dV in regime I) / (maximum peak height of dQ / dV in regime III), (wherein dQ / dV is measured in a half-cell coin cell, with regime I being 0.8V to 0.4V and regime III being 0.15V to 0V).

[0282] Embodiment 37. A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 25 to 28, wherein the silicon-carbon composite contains Dv50 particles ranging from 5 nm to 20 microns.

[0283] Embodiment 38. A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 25 to 28, wherein the silicon-carbon composite has a capacity greater than 900 mA / g.

[0284] Embodiment 39. A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 25 to 28, wherein the silicon-carbon composite has a capacity greater than 1300 mA / g.

[0285] Embodiment 40. A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 25 to 28, wherein the silicon-carbon composite has a capacity greater than 1600 mA / g.

[0286] Embodiment 41. A method for producing passivated silicon-carbon composite particles, the following: a. To provide a carbon scaffold having a pore volume containing more than 70% microporosity; b. Heating porous carbon scaffold particles to 350°C to 550°C in the presence of silane gas; and c. Cooling the silicon-carbon composite in the presence of propylene gas. A manufacturing method that includes this.

[0287] Embodiment 42. A method for producing passivated silicon-carbon composite particles, the following: a. To provide a carbon scaffold having a pore volume containing more than 70% microporosity; b. Heating porous carbon scaffold particles to 350°C to 550°C in the presence of silane gas; c. Cooling the silicon-carbon composite in the presence of propylene gas; and d. Here, the passivated silicon-carbon composite is as follows: i. Includes Z less than 10, where Z = 1.875 × [(M1100-M) / M1100] × 100%, (wherein, when the silicon-carbon composite is heated in air from approximately 25°C to approximately 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C, and these masses are determined by thermogravimetric analysis.) Calculated from, A manufacturing method that includes this.

[0288] Embodiment 43. A method for producing passivated silicon-carbon composite particles, the following: a. To provide a carbon scaffold having a pore volume containing more than 70% microporosity; b. Heating porous carbon scaffold particles to 350°C to 550°C in the presence of silane gas; c. Cooling the silicon-carbon composite in the presence of propylene gas; and d. Here, the passivated silicon-carbon composite is as follows: i. Z less than 10, where Z is, Z = 1.875 × [(M1100-M) / M1100] × 100%, (wherein, when the silicon-carbon composite is heated in air from approximately 25°C to approximately 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C, and these masses are determined by thermogravimetric analysis.) is used for calculation; and ii.0.1 includes φ greater than or equal to, where said φ is, φ is calculated from φ = (maximum peak height of dQ / dV in regime I) / (maximum peak height of dQ / dV in regime III), (wherein dQ / dV is measured in a half-cell coin cell, with regime I being 0.8V to 0.4V and regime III being 0.15V to 0V). A manufacturing method that includes this.

[0289] Embodiment 44. A method for producing passivated silicon-carbon composite particles, the following: a. To provide a carbon scaffold having a pore volume containing more than 70% microporosity; b. Heating porous carbon scaffold particles to 350°C to 550°C in the presence of silane gas; c. Cooling the silicon-carbon composite in the presence of propylene gas; and d. Here, the passivated silicon-carbon composite is as follows: i. Silicone content of 30% to 60% by weight; ii. 30m 2 Surface area less than / g; iii. Z less than 10, where Z is, Z = 1.875 × [(M1100-M) / M1100] × 100%, (wherein, when the silicon-carbon composite is heated in air from approximately 25°C to approximately 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C, and these masses are determined by thermogravimetric analysis.) is used for calculation; and iv.0.1 includes φ greater than or equal to, where φ is, φ is calculated from φ = (maximum peak height of dQ / dV in regime I) / (maximum peak height of dQ / dV in regime III), (wherein dQ / dV is measured in a half-cell coin cell, with regime I being 0.8V to 0.4V and regime III being 0.15V to 0V). A manufacturing method that includes this.

[0290] Embodiment 45. A method for producing passivated silicon-carbon composite particles, the following: a. To provide a carbon scaffold having a pore volume containing more than 70% microporosity; b. Heating porous carbon scaffold particles to 350°C to 550°C in the presence of silane gas; and c. Cool the silicon-carbon composite to a temperature between 100°C and 300°C in the presence of acetylene gas. A manufacturing method that includes this.

[0291] Embodiment 46. A method for producing passivated silicon-carbon composite particles, the following: a. To provide a carbon scaffold having a pore volume containing more than 70% microporosity; b. Heating porous carbon scaffold particles to 350°C to 550°C in the presence of silane gas; c. Cooling the silicon-carbon composite to a temperature between 100°C and 300°C in the presence of acetylene gas; and d. Here, the passivated silicon-carbon composite is as follows: i. Includes Z less than 10, where Z is: Z = 1.875 × [(M1100 - M) / M1100] × 100%, (wherein, when the silicon-carbon composite is heated in air from approximately 25°C to approximately 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C. These masses are determined by thermogravimetric analysis.) A manufacturing method that includes this.

[0292] Embodiment 47. A method for producing passivated silicon-carbon composite particles, the following: a. To provide a carbon scaffold having a pore volume containing more than 70% microporosity; b. Heating porous carbon scaffold particles to 350°C to 550°C in the presence of silane gas; c. Cooling the silicon-carbon composite to between 100°C and 300°C in the presence of acetylene gas; and d. Here, the passivated silicon-carbon composite is as follows: i. Z less than 10, where Z is, Z = 1.875 × [(M1100-M) / M1100] × 100%, (wherein, when the silicon-carbon composite is heated in air from approximately 25°C to approximately 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C, and these masses are determined by thermogravimetric analysis.) is used for calculation; and ii.0.1 includes φ greater than or equal to, where said φ is, φ is calculated from φ = (maximum peak height of dQ / dV in regime I) / (maximum peak height of dQ / dV in regime III), (wherein dQ / dV is measured in a half-cell coin cell, with regime I being 0.8V to 0.4V and regime III being 0.15V to 0V). A manufacturing method that includes this.

[0293] Embodiment 48. A method for producing passivated silicon-carbon composite particles, the following: a. To provide a carbon scaffold having a pore volume containing more than 70% microporosity; b. Heating porous carbon scaffold particles to 350°C to 550°C in the presence of silane gas; c. Cooling the silicon-carbon composite to between 100°C and 300°C in the presence of acetylene gas; and d. Here, the passivated silicon-carbon composite is as follows: i. Silicone content of 30% to 60% by weight; ii. 30m 2 Surface area less than / g; iii. Z less than 10, where Z is, Z=1.875×[(M1100-M) / M1100]×100%, (In the formula, when the silicon-carbon composite is heated in air from approximately 25°C to approximately 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C, and these masses are determined by thermogravimetric analysis.) and iv.0.1 includes φ greater than or equal to, where φ is, φ is calculated from φ = (maximum peak height of dQ / dV in regime I) / (maximum peak height of dQ / dV in regime III), (wherein dQ / dV is measured in a half-cell coin cell, with regime I being 0.8V to 0.4V and regime III being 0.15V to 0V). A manufacturing method that includes this.

[0294] A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 41 to 48, comprising a pore volume having more than 9.80% microporosity.

[0295] A method for producing passivated silicon-carbon composite particles according to any one of embodiments 41 to 48, comprising a pore volume having more than 50.90% microporosity.

[0296] A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 41 to 48, comprising a pore volume having more than 1.95% microporosity.

[0297] Embodiment 52. A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 41 to 48, wherein the silicon-carbon composite contains a silicon content of 40% to 60%.

[0298] Embodiment 53. A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 41 to 48, wherein the silicon-carbon composite contains Z less than 5.

[0299] Embodiment 54. A silicon-carbon composite is 10 m 2 A method for producing passivated silicon-carbon composite particles according to any one of embodiments 41 to 48, including a surface area of ​​less than / g.

[0300] Embodiment 55. A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 41 to 48, wherein the silicon-carbon composite contains a φ of 0.2 or more. Here, the φ is φ is calculated from φ = (maximum peak height of dQ / dV in regime I) / (maximum peak height of dQ / dV in regime III), (wherein dQ / dV is measured in a half-cell coin cell, with regime I being 0.8V to 0.4V and regime III being 0.15V to 0V).

[0301] Embodiment 56. A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 41 to 48, wherein the silicon-carbon composite contains a φ of 0.3 or more. Here, the φ is φ is calculated from φ = (maximum peak height of dQ / dV in regime I) / (maximum peak height of dQ / dV in regime III), (wherein dQ / dV is measured in a half-cell coin cell, with regime I being 0.8V to 0.4V and regime III being 0.15V to 0V).

[0302] Embodiment 57. A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 41 to 48, wherein the silicon-carbon composite contains Dv50 particles ranging from 5 nm to 20 microns in size.

[0303] Embodiment 58. A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 41 to 48, wherein the silicon-carbon composite has a capacity greater than 900 mA / g.

[0304] Embodiment 59. A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 41 to 48, wherein the silicon-carbon composite has a capacity greater than 1300 mA / g.

[0305] Embodiment 60. A method for producing passivated silicon-carbon composite particles according to any one of Embodiments 41 to 48, wherein the silicon-carbon composite has a capacity greater than 1600 mA / g.

[0306] Embodiment 61. A silicon-carbon composite, the following: a. Carbon scaffold containing pore volume with over 70% microporosity; b. Z less than 10, where Z is, Z=1.875×[(M1100-M) / M1100]×100%, (In the formula, when the silicon-carbon composite is heated in air from approximately 25°C to approximately 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C, and these masses are determined by thermogravimetric analysis.) and c. One or more layers of passivated silicon located beneath the terminal passivated silicon surface, A silicon-carbon composite, including [the aforementioned material].

[0307] Embodiment 62. The silicon-carbon composite according to Embodiment 61, wherein the silicon-carbon composite further contains a silicon content of 30% to 60% by weight.

[0308] Embodiment 63. A silicon-carbon composite according to any one of Embodiments 61 to 62, wherein the silicon-carbon composite consists of particles containing Dv50 ranging in size from 5 nm to 20 microns.

[0309] Embodiment 64. A silicon-carbon composite according to any one of Embodiments 61 to 63, wherein the silicon-carbon composite includes a φ of 0.1 or more, where the φ is φ is calculated from φ = (maximum peak height of dQ / dV in regime I) / (maximum peak height of dQ / dV in regime III), (wherein dQ / dV is measured in a half-cell coin cell, with regime I being 0.8V to 0.4V and regime III being 0.15V to 0V).

[0310] Embodiment 65. The silicon-carbon composite according to any one of Embodiments 61 to 64, wherein the passivated silicon layer is a silicon oxide layer.

[0311] Embodiment 66. A method for producing hydrosilylated passivated silicon-carbon composite particles, the following: a. To provide carbon scaffold particles having a pore volume containing more than 70% microporosity; b. Manufacturing silicon-carbon composite particles by contacting porous carbon scaffold particles with silane gas at 350°C to 550°C; and c. The above silicon-carbon composite particles are brought into contact with an alkene gas at 100°C to 500°C to produce hydrosilylated passivated silicon-carbon composite particles. A manufacturing method that includes this.

[0312] Embodiment 67. A method for producing hydrosilylated passivated silicon-carbon composite particles, the following: a. To provide carbon scaffold particles having a pore volume containing more than 70% microporosity; b. Manufacturing silicon-carbon composite particles by contacting porous carbon scaffold particles with silane gas at 350°C to 550°C; and c. The above silicon-carbon composite particles are brought into contact with alkyne gas at 100°C to 500°C to produce hydrosilylated passivated silicon-carbon composite particles. A manufacturing method that includes this.

[0313] Embodiment 68. A method for producing hydrosilylated passivated silicon-carbon composite particles, the following: a. To provide carbon scaffold particles having a pore volume containing more than 70% microporosity; b. Manufacturing silicon-carbon composite particles by contacting porous carbon scaffold particles with silane gas at 350°C to 550°C; and c. The above silicon-carbon composite particles are brought into contact with acetylene gas at 100°C to 500°C to produce hydrosilylated passivated silicon-carbon composite particles. A manufacturing method that includes this.

[0314] Embodiment 69. A method for producing hydrosilylated passivated silicon-carbon composite particles, the following: a. To provide carbon scaffold particles having a pore volume containing more than 70% microporosity; b. Manufacturing silicon-carbon composite particles by contacting porous carbon scaffold particles with silane gas at 350°C to 550°C; and c. The above silicon-carbon composite particles are brought into contact with propylene gas at 100°C to 500°C to produce hydrosilylated passivated silicon-carbon composite particles. A manufacturing method that includes this.

[0315] Embodiment 70. A method for producing hydrosilylated passivated silicon-carbon composite particles, the following: a. To provide carbon scaffold particles having a pore volume containing more than 70% microporosity; b. Manufacturing silicon-carbon composite particles by contacting porous carbon scaffold particles with silane gas at 350°C to 550°C; and c. The above silicon-carbon composite particles are brought into contact with ethylene gas at 100°C to 500°C to produce hydrosilylated passivated silicon-carbon composite particles. A manufacturing method that includes this.

[0316] Embodiment 71. A method for producing hydrosilylated passivated silicon-carbon composite particles, the following: a. To provide carbon scaffold particles having a pore volume containing more than 70% microporosity; b. Silicon-carbon composite particles are produced by contacting porous carbon scaffold particles with silane gas at 350°C to 550°C; c. Contacting the above silicon-carbon composite particles with acetylene gas at 100°C to 500°C to produce hydrosilylated passivated silicon-carbon composite particles; and d. Here, the passivated silicon-carbon composite is as follows: i. Silicone content of 30% to 60% by weight; ii. 30m 2 Surface area less than / g; iii. Z less than 10, where Z is, Z = 1.875 × [(M1100-M) / M1100] × 100%, (wherein, when the silicon-carbon composite is heated in air from approximately 25°C to approximately 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C, and these masses are determined by thermogravimetric analysis.) is used for calculation; and iv.0.1 includes φ greater than or equal to, where φ is, φ is calculated from φ = (maximum peak height of dQ / dV in regime I) / (maximum peak height of dQ / dV in regime III), (wherein dQ / dV is measured in a half-cell coin cell, with regime I being 0.8V to 0.4V and regime III being 0.15V to 0V). A manufacturing method that includes this.

[0317] Embodiment 72. A method for producing hydrosilylated passivated silicon-carbon composite particles, the following: a. To provide carbon scaffold particles having a pore volume containing more than 70% microporosity; b. Silicon-carbon composite particles are produced by contacting porous carbon scaffold particles with silane gas at 350°C to 550°C; c. Contacting the above silicon-carbon composite particles with propylene gas at 100°C to 500°C to produce hydrosilylated passivated silicon-carbon composite particles; and d. Here, the passivated silicon-carbon composite is as follows: i. Silicone content of 30% to 60% by weight; ii. 30m 2 Surface area less than / g; iii. Z less than 10, where Z is, Z = 1.875 × [(M1100-M) / M1100] × 100%, (wherein, when the silicon-carbon composite is heated in air from approximately 25°C to approximately 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C, and these masses are determined by thermogravimetric analysis.) is used for calculation; and iv.0.1 includes φ greater than or equal to, where φ is, φ is calculated from φ = (maximum peak height of dQ / dV in regime I) / (maximum peak height of dQ / dV in regime III), (wherein dQ / dV is measured in a half-cell coin cell, with regime I being 0.8V to 0.4V and regime III being 0.15V to 0V). A manufacturing method that includes this.

[0318] Embodiment 73. A method for producing hydrosilylated passivated silicon-carbon composite particles, the following: a. To provide carbon scaffold particles having a pore volume containing more than 70% microporosity; b. Silicon-carbon composite particles are produced by contacting porous carbon scaffold particles with silane gas at 350°C to 550°C; c. Contacting the above silicon-carbon composite particles with ethylene gas at 100°C to 500°C to produce hydrosilylated passivated silicon-carbon composite particles; and d. Here, the passivated silicon-carbon composite is as follows: i. Silicone content of 30% to 60% by weight; ii. 30m 2 Surface area less than / g; iii. Z less than 10, where Z is, Z = 1.875 × [(M1100-M) / M1100] × 100%, (wherein, when the silicon-carbon composite is heated in air from approximately 25°C to approximately 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C, and these masses are determined by thermogravimetric analysis.) is used for calculation; and iv.0.1 includes φ greater than or equal to, where φ is, φ is calculated from φ = (maximum peak height of dQ / dV in regime I) / (maximum peak height of dQ / dV in regime III), (wherein dQ / dV is measured in a half-cell coin cell, with regime I being 0.8V to 0.4V and regime III being 0.15V to 0V). A manufacturing method that includes this.

[0319] Embodiment 74. A silicon-carbon composite material, the following: a. Carbon scaffolds with a pore volume containing more than 70% microporosity; b. Nano-sized silicon domains within the pores of porous carbon containing Si-R bonds on the silicon surface; c. The above R is as follows: a. Organic functional groups containing a combination of carbon, oxygen, nitrogen, or hydrogen; and b. further comprising one or more halogen elements, such as bromine, fluorine, chlorine, or iodine; and d. Passivated silicon-carbon composites are as follows: i. Silicone content of 30% to 60% by weight; ii. 30m 2 Surface area less than / g; iii. Z less than 10, where Z is, Z = 1.875 × [(M1100-M) / M1100] × 100%, (wherein, when the silicon-carbon composite is heated in air from approximately 25°C to approximately 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C, and these masses are determined by thermogravimetric analysis.) is used for calculation; and iv.0.1 includes φ greater than or equal to, where φ is, φ is calculated from φ = (maximum peak height of dQ / dV in regime I) / (maximum peak height of dQ / dV in regime III), (wherein dQ / dV is measured in a half-cell coin cell, with regime I being 0.8V to 0.4V and regime III being 0.15V to 0V). A hydrosilylated passivated silicon-carbon composite material containing this material.

[0320] Embodiment 75. A method for producing chemically vapor-passivated silicon-carbon composite particles, the following: a. To provide carbon scaffold particles having a pore volume containing more than 70% microporosity; b. Manufacturing silicon-carbon composite particles by contacting porous carbon scaffold particles with silane gas at 350°C to 550°C; and c. The above silicon-carbon composite particles are brought into contact with an alkane gas at 300°C to 700°C to produce chemically vapor-passivated silicon-carbon composite particles. A manufacturing method that includes this.

[0321] Embodiment 76. A method for producing chemically vapor-passivated silicon-carbon composite particles, the following: a. To provide carbon scaffold particles having a pore volume containing more than 70% microporosity; b. Manufacturing silicon-carbon composite particles by contacting porous carbon scaffold particles with silane gas at 350°C to 550°C; and c. The above silicon-carbon composite particles are brought into contact with alkyne gas at 300°C to 700°C to produce chemically vapor-passivated silicon-carbon composite particles. A manufacturing method that includes this.

[0322] Embodiment 77. A method for producing chemically vapor-passivated silicon-carbon composite particles, the following: a. To provide a carbon scaffold having a pore volume containing more than 70% microporosity; b. Manufacturing silicon-carbon composite particles by contacting porous carbon scaffold particles with silane gas at 350°C to 550°C; and c. The above silicon-carbon composite particles are brought into contact with acetylene gas at 300°C to 700°C to produce chemically vapor-passivated silicon-carbon composite particles. A manufacturing method that includes this.

[0323] Embodiment 78. A method for producing chemically vapor-passivated silicon-carbon composite particles, the following: a. To provide carbon scaffold particles having a pore volume containing more than 70% microporosity; b. Manufacturing silicon-carbon composite particles by contacting porous carbon scaffold particles with silane gas at 350°C to 550°C; and c. The above silicon-carbon composite particles are brought into contact with propylene gas at 300°C to 700°C to produce chemically vapor-passivated silicon-carbon composite particles. A manufacturing method that includes this.

[0324] Embodiment 79. A method for producing chemically vapor-passivated silicon-carbon composite particles, the following: a. To provide carbon scaffold particles having a pore volume containing more than 70% microporosity; b. Manufacturing silicon-carbon composite particles by contacting porous carbon scaffold particles with silane gas at 350°C to 550°C; and c. The above silicon-carbon composite particles are brought into contact with ethylene gas at 300°C to 700°C to produce chemically vapor-passivated silicon-carbon composite particles. A manufacturing method that includes this.

[0325] Embodiment 80. A method for producing chemically vapor-passivated silicon-carbon composite particles, the following: a. To provide carbon scaffold particles having a pore volume containing more than 70% microporosity; b. Silicon-carbon composite particles are produced by contacting porous carbon scaffold particles with silane gas at 350°C to 550°C; c. The above silicon-carbon composite particles are brought into contact with acetylene gas at 300°C to 700°C to produce chemically vapor-passivated silicon-carbon composite particles; and d. Here, the passivated silicon-carbon composite is as follows: i. Silicone content of 30% to 60% by weight; ii. 30m 2 Surface area less than / g; iii. Z less than 10, where Z is, Z = 1.875 × [(M1100-M) / M1100] × 100%, (wherein, when the silicon-carbon composite is heated in air from approximately 25°C to approximately 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C, and these masses are determined by thermogravimetric analysis.) is used for calculation; and iv.0.1 includes φ greater than or equal to, where φ is, φ is calculated from φ = (maximum peak height of dQ / dV in regime I) / (maximum peak height of dQ / dV in regime III), (wherein dQ / dV is measured in a half-cell coin cell, with regime I being 0.8V to 0.4V and regime III being 0.15V to 0V). A manufacturing method that includes this.

[0326] Embodiment 81. A method for producing chemically vapor-passivated silicon-carbon composite particles, the following: a. To provide carbon scaffold particles having a pore volume containing more than 70% microporosity; b. Silicon-carbon composite particles are produced by contacting porous carbon scaffold particles with silane gas at 350°C to 550°C; c. The above silicon-carbon composite particles are brought into contact with propylene gas at 300°C to 700°C to produce chemically vapor-passivated silicon-carbon composite particles; and d. Here, the passivated silicon-carbon composite is as follows: i. Silicone content of 30% to 60% by weight; ii. 30m 2 Surface area less than / g; iii. Z less than 10, where Z is, Z = 1.875 × [(M1100-M) / M1100] × 100%, (wherein, when the silicon-carbon composite is heated in air from approximately 25°C to approximately 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C, and these masses are determined by thermogravimetric analysis.) is used for calculation; and iv.0.1 includes φ greater than or equal to, where φ is, φ is calculated from φ = (maximum peak height of dQ / dV in regime I) / (maximum peak height of dQ / dV in regime III), (wherein dQ / dV is measured in a half-cell coin cell, with regime I being 0.8V to 0.4V and regime III being 0.15V to 0V). A manufacturing method that includes this.

[0327] Embodiment 82. A method for producing chemically vapor-passivated silicon-carbon composite particles, the following: a. To provide carbon scaffold particles having a pore volume containing more than 70% microporosity; b. Silicon-carbon composite particles are produced by contacting porous carbon scaffold particles with silane gas at 350°C to 550°C; c. The above silicon-carbon composite particles are brought into contact with ethylene gas at 300°C to 700°C to produce chemically vapor-passivated silicon-carbon composite particles; and d. Here, the passivated silicon-carbon composite is as follows: i. Silicone content of 30% to 60% by weight; ii. 30m 2 Surface area less than / g; iii. Z less than 10, where Z is, Z = 1.875 × [(M1100-M) / M1100] × 100%, (wherein, when the silicon-carbon composite is heated in air from approximately 25°C to approximately 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C, and these masses are determined by thermogravimetric analysis.) is used for calculation; and iv.0.1 includes φ greater than or equal to, where φ is, φ is calculated from φ = (maximum peak height of dQ / dV in regime I) / (maximum peak height of dQ / dV in regime III), (wherein dQ / dV is measured in a half-cell coin cell, with regime I being 0.8V to 0.4V and regime III being 0.15V to 0V). A manufacturing method that includes this.

[0328] Embodiment 83. A silicon-carbon composite material, the following: a. Carbon scaffolds with a pore volume containing more than 70% microporosity; b. Nano-sized silicon domains within the pores of porous carbon containing Si-H bonds on the silicon surface; c. A carbonaceous layer covering at least partially the silicon domain; and d. Here, the passivated silicon-carbon composite is as follows: i. Silicone content of 30% to 60% by weight; ii. 30m 2 Surface area less than / g; iii. Z less than 10, where Z is, Z = 1.875 × [(M1100-M) / M1100] × 100%, (wherein, when the silicon-carbon composite is heated in air from approximately 25°C to approximately 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C, and these masses are determined by thermogravimetric analysis.) is used for calculation; and iv.0.1 includes φ greater than or equal to, where φ is, φ is calculated from φ = (maximum peak height of dQ / dV in regime I) / (maximum peak height of dQ / dV in regime III), (wherein dQ / dV is measured in a half-cell coin cell, with regime I being 0.8V to 0.4V and regime III being 0.15V to 0V). A chemical vapor-passivated silicon-carbon composite material, including [specific material].

[0329] From the above, it will be understood that while specific embodiments of the present invention have been described herein for disclosure purposes, various modifications may be made without departing from the spirit and scope of the invention. Accordingly, the present invention is not limited except as provided for in the appended claims.

[0330] This application claims priority to U.S. Provisional Application No. 63 / 085,788 (filed September 30, 2020) and U.S. Provisional Application No. 63 / 129,363 (filed December 22, 2020), the disclosures herein fully incorporated by reference.

Claims

1. Passivated silicon-carbon composite, the following: a. Carbon scaffolds containing pore volume with over 70% microporosity; b. Z less than 10, where Z is given by the following formula: Z=1.875×((M1100-M) / M1100)×100% [In the formula, when the silicon-carbon composite is heated in air from approximately 25°C to approximately 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C, both measured by thermogravimetric analysis.] It is represented c. One or more layers of passivated silicon located beneath the terminal passivated silicon surface; and d. The silicon-carbon composite contains φ of 0.1 or greater, where φ is given by the following formula: φ = (Maximum peak height dQ / dV in Regime I) / (Maximum peak height dQ / dV in Regime III) [In the formula, dQ / dV is measured in a half-cell coin cell, with Regime I being 0.8V to 0.4V and Regime III being 0.15V to 0V.] Represented by, A passivated silicon-carbon composite, including [the specified component].

2. The composition according to claim 1, wherein the silicon-carbon composite contains a silicon content of 30% to 60% by weight.

3. The composition according to claim 1, wherein the silicon-carbon composite comprises Dv50 ranging from 5 nm to 20 microns.

4. A silicon-carbon composite, 30m ２ The composition according to claim 1, comprising a surface area of ​​less than 1g.

5. A silicon-carbon composite, 10m ２ The composition according to claim 4, comprising a surface area of ​​less than / g.

6. A method for producing passivated silicon-carbon composite particles, the following: a. To provide a carbon scaffold containing a pore volume having more than 70% microporosity; b. Heating porous carbon scaffold particles to 350°C to 550°C in the presence of silane gas; c. Adjust the temperature to 400°C or below in the presence of nitrogen gas; d. Introducing an oxygen-containing passivation gas; e. Here, the passivated silicon-carbon composite is as follows: i. Includes Z less than 10, where Z is given by the following formula: Z=1.875×((M1100-M) / M1100)×100% [In the formula, when the silicon-carbon composite is heated in air from about 25°C to about 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C, both measured by thermogravimetric analysis.] Represented by; and f. The silicon-carbon composite contains φ of 0.1 or greater, where φ is given by the following formula: φ = (Maximum peak height dQ / dV in Regime I) / (Maximum peak height dQ / dV in Regime III) [In the formula, dQ / dV is measured in a half-cell coin cell, with Regime I being 0.8V to 0.4V and Regime III being 0.15V to 0V.] Represented by, A manufacturing method that includes this.

7. A method for producing passivated silicon-carbon composite particles according to claim 6, wherein the silicon-carbon composite contains a silicon content of 30% to 60% by weight.

8. A method for producing passivated silicon-carbon composite particles according to claim 6, wherein the silicon-carbon composite contains Dv50 particles ranging from 5 nm to 20 microns.

9. A method for producing passivated silicon-carbon composite particles according to claim 6, wherein the oxygen-containing passivation gas contains ethanol.

10. A method for producing passivated silicon-carbon composite particles according to claim 6, wherein the oxygen-containing passivation gas is selected from the group consisting of dimethyl carbonate, ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, or vinylene carbonate, or a combination thereof.

11. A silicon-carbon composite, 30m ２ A method for producing passivated silicon-carbon composite particles according to claim 6, comprising a surface area of ​​less than 1g.

12. A silicon-carbon composite, 10m ２ A method for producing passivated silicon-carbon composite particles according to claim 11, comprising a surface area of ​​less than 1g.

13. A method for producing passivated silicon-carbon composite particles, the following: a. To provide a carbon scaffold containing a pore volume having more than 70% microporosity; b. Heating porous carbon scaffold particles to 350°C to 550°C in the presence of silane gas; c. Switching the process gas between silane gas and carbon dioxide gas; d. Here, the passivated silicon-carbon composite is as follows: i. Includes Z less than 10, where Z is given by the following formula: Z=1.875×((M1100-M) / M1100)×100% [In the formula, when the silicon-carbon composite is heated in air from about 25°C to about 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C, both measured by thermogravimetric analysis.] Represented by; and e. The silicon-carbon composite contains φ of 0.1 or greater, where φ is given by the following formula: φ = (Maximum peak height dQ / dV in Regime I) / (Maximum peak height dQ / dV in Regime III) [In the formula, dQ / dV is measured in a half-cell coin cell, with Regime I being 0.8V to 0.4V and Regime III being 0.15V to 0V.] Represented by, A manufacturing method that includes this.

14. A method for producing passivated silicon-carbon composite particles according to claim 13, wherein the silicon-carbon composite contains a silicon content of 30% to 60% by weight.

15. A method for producing passivated silicon-carbon composite particles according to claim 13, wherein the silicon-carbon composite contains Dv50 particles ranging from 5 nm to 20 microns.

16. A silicon-carbon composite, 30m ２ A method for producing passivated silicon-carbon composite particles according to claim 13, comprising a surface area of ​​less than 1g.

17. A silicon-carbon composite, 10m ２ A method for producing passivated silicon-carbon composite particles according to claim 16, comprising a surface area of ​​less than 1g.

18. A method for producing passivated silicon-carbon composite particles, the following: a. To provide a carbon scaffold containing a pore volume having more than 70% microporosity; b. Heating porous carbon scaffold particles to 350°C to 550°C in the presence of silane gas; c. Cooling the silicon-carbon composite in the presence of propylene gas; d. Here, the silicon-carbon composite is as follows: i. Includes Z less than 10, where Z is given by the following formula: Z=1.875×((M1100-M) / M1100)×100% [In the formula, when the silicon-carbon composite is heated in air from about 25°C to about 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C, both measured by thermogravimetric analysis.] Represented by; and e. The silicon-carbon composite contains φ of 0.1 or greater, where φ is given by the following formula: φ = (Maximum peak height dQ / dV in Regime I) / (Maximum peak height dQ / dV in Regime III) [In the formula, dQ / dV is measured in a half-cell coin cell, with Regime I being 0.8V to 0.4V and Regime III being 0.15V to 0V.] Represented by, A manufacturing method that includes this.

19. A method for producing passivated silicon-carbon composite particles according to claim 18, wherein the silicon-carbon composite contains a silicon content of 30% to 60% by weight.

20. A method for producing passivated silicon-carbon composite particles according to claim 18, wherein the silicon-carbon composite contains Dv50 particles ranging from 5 nm to 20 microns.

21. A silicon-carbon composite, 30m ２ A method for producing passivated silicon-carbon composite particles according to claim 18, comprising a surface area of ​​less than 1g.

22. A silicon-carbon composite, 10m ２ A method for producing passivated silicon-carbon composite particles according to claim 21, comprising a surface area of ​​less than 1g.

23. A method for producing passivated silicon-carbon composite particles, the following: a. To provide a carbon scaffold containing a pore volume having more than 70% microporosity; b. Heating porous carbon scaffold particles to 350°C to 550°C in the presence of silane gas; c. Cooling the silicon-carbon composite to 100°C to 300°C in the presence of acetylene gas; and d. Here, the silicon-carbon composite is as follows: i. Z less than 10, where Z is given by the following formula: Z=1.875×((M1100-M) / M1100)×100% [In the formula, when the silicon-carbon composite is heated in air from about 25°C to about 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C, both measured by thermogravimetric analysis.] Represented by; and e. The silicon-carbon composite contains φ of 0.1 or greater, where φ is given by the following formula: φ = (Maximum peak height dQ / dV in Regime I) / (Maximum peak height dQ / dV in Regime III) [In the formula, dQ / dV is measured in a half-cell coin cell, with Regime I being 0.8V to 0.4V and Regime III being 0.15V to 0V.] Represented by, A manufacturing method that includes this.

24. A method for producing passivated silicon-carbon composite particles according to claim 23, wherein the silicon-carbon composite contains a silicon content of 30% to 60% by weight.

25. A method for producing passivated silicon-carbon composite particles according to claim 23, wherein the silicon-carbon composite contains Dv50 particles ranging from 5 nm to 20 microns.

26. The method for producing passivated silicon-carbon composite particles according to claim 23, wherein the silicon-carbon composite has a surface area of less than 30 m ２ / g.

27. A silicon-carbon composite, 10m ２ A method for producing passivated silicon-carbon composite particles according to claim 26, comprising a surface area of ​​less than 1g.

28. A silicon-carbon composite, which is as follows: a. Carbon scaffolds containing pore volume with over 70% microporosity; b. Z less than 10, where Z is given by the following formula: Z=1.875×((M1100-M) / M1100)×100% [In the formula, when the silicon-carbon composite is heated in air from about 25°C to about 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C, both measured by thermogravimetric analysis.] It is represented by; c. Silicon content of 30% to 60% by weight; d. Dv50 in the range of 5 nm to 20 microns; e. Molar ratio of oxygen to silicon less than 0.5 mol / mol; and f. The silicon-carbon composite contains φ of 0.1 or greater, where φ is given by the following formula: φ = (Maximum peak height dQ / dV in Regime I) / (Maximum peak height dQ / dV in Regime III) [In the formula, dQ / dV is measured in a half-cell coin cell, with Regime I being 0.8V to 0.4V and Regime III being 0.15V to 0V.] Represented by, A passivated silicon-carbon composite, including [the specified component].

29. A silicon-carbon composite, which is as follows: a. Carbon scaffolds containing pore volume with over 70% microporosity; b. Z less than 10, where Z is given by the following formula: Z=1.875×((M1100-M) / M1100)×100% [In the formula, when the silicon-carbon composite is heated in air from about 25°C to about 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C, both measured by thermogravimetric analysis.] It is represented by; c. Silicon content of 30% to 60% by weight; d. Dv50 in the range of 5 nm to 20 microns; e. Molar ratio of oxygen to silicon less than 0.5 mol / mol; f. When exposed to air at 25°C, the molar ratio of oxygen to silicon increases by less than 0.01 mol / mol per day; and g. The silicon-carbon composite contains φ of 0.1 or greater, where φ is given by the following formula: φ = (Maximum peak height dQ / dV in Regime I) / (Maximum peak height dQ / dV in Regime III) [In the formula, dQ / dV is measured in a half-cell coin cell, with Regime I being 0.8V to 0.4V and Regime III being 0.15V to 0V.] Represented by, A passivated silicon-carbon composite, including [the specified component].

30. A passivated silicon-carbon composite according to any one of claims 28 to 29, wherein the molar ratio of oxygen to silicon is less than 0.1 mol / mol.

31. A passivated silicon-carbon composite according to any one of claims 28 to 29, wherein the molar ratio of oxygen to silicon is less than 0.05 mol / mol.

32. A passivated silicon-carbon composite according to any one of claims 28 to 29, wherein the molar ratio of oxygen to silicon is less than 0.01 mol / mol.

33. A passivated silicon-carbon composite according to any one of claims 28 to 29, wherein the molar ratio of oxygen to silicon is less than 0.005 mol / mol.

34. A passivated silicon-carbon composite according to any one of claims 28 to 29, wherein the molar ratio of oxygen to silicon is less than 0.001 mol / mol.

35. A passivated silicon-carbon composite according to any one of claims 28 to 34, wherein, when exposed to air at 25°C, the molar ratio of oxygen to silicon increases by less than 0.005 mol / mol per day.

36. A passivated silicon-carbon composite according to any one of claims 28 to 34, wherein, when exposed to air at 25°C, the molar ratio of oxygen to silicon increases by less than 0.001 mol / mol per day.

37. A passivated silicon-carbon composite according to any one of claims 28 to 34, wherein, when exposed to air at 25°C, the molar ratio of oxygen to silicon increases by less than 0.0005 mol / mol per day.

38. A passivated silicon-carbon composite according to any one of claims 28 to 34, wherein, when exposed to air at 25°C, the molar ratio of oxygen to silicon increases by less than 0.0001 mol / mol per day.

39. A method for producing hydrosilylated passivated silicon-carbon composite particles, the following: a. To provide carbon scaffold particles containing pore volume having more than 70% microporosity; b. Manufacturing silicon-carbon composite particles by contacting porous carbon scaffold particles with silane gas at 350°C to 550°C; c. Contacting the silicon-carbon composite particles with an alkene gas at 100°C to 500°C to produce hydrosilylated passivated silicon-carbon composite particles; and d. The silicon-carbon composite contains φ of 0.1 or greater, where φ is given by the following formula: φ = (Maximum peak height dQ / dV in Regime I) / (Maximum peak height dQ / dV in Regime III) [In the formula, dQ / dV is measured in a half-cell coin cell, with Regime I being 0.8V to 0.4V and Regime III being 0.15V to 0V.] Represented by, A manufacturing method that includes this.

40. A method for producing hydrosilylated passivated silicon-carbon composite particles, the following: a. To provide carbon scaffold particles containing pore volume having more than 70% microporosity; b. Manufacturing silicon-carbon composite particles by contacting porous carbon scaffold particles with silane gas at 350°C to 550°C; c. Contacting the silicon-carbon composite particles with alkyne gas at 100°C to 500°C to produce hydrosilylated passivated silicon-carbon composite particles; and d. The silicon-carbon composite contains φ of 0.1 or greater, where φ is given by the following formula: φ = (Maximum peak height dQ / dV in Regime I) / (Maximum peak height dQ / dV in Regime III) [In the formula, dQ / dV is measured in a half-cell coin cell, with Regime I being 0.8V to 0.4V and Regime III being 0.15V to 0V.] Represented by, A manufacturing method that includes this.

41. A method for producing hydrosilylated passivated silicon-carbon composite particles, the following: a. To provide carbon scaffold particles containing pore volume having more than 70% microporosity; b. Manufacturing silicon-carbon composite particles by contacting porous carbon scaffold particles with silane gas at 350°C to 550°C; and c. Contacting the silicon-carbon composite particles with acetylene gas at 100°C to 500°C to produce hydrosilylated passivated silicon-carbon composite particles; and d. The silicon-carbon composite contains φ of 0.1 or greater, where φ is given by the following formula: φ = (Maximum peak height dQ / dV in Regime I) / (Maximum peak height dQ / dV in Regime III) [In the formula, dQ / dV is measured in a half-cell coin cell, with Regime I being 0.8V to 0.4V and Regime III being 0.15V to 0V.] Represented by, A manufacturing method that includes this.

42. A silicon-carbon composite material, which is as follows: a. Carbon scaffolds containing pore volume with over 70% microporosity; b. Nano-sized silicon domains within the pores of porous carbon, where the silicon surface contains Si-R bonds; c. The above R is as follows: i. Organic functional groups comprising a combination of carbon, oxygen, nitrogen, or hydrogen; and ii. One or more additional halogen elements (e.g., boron, fluorine, chlorine, or iodine), Including; and d. Silicon-carbon composites are as follows: i. Silicon content of 30% to 60% by weight; ii. 30m ２ Surface area less than / g; iii. Z less than 10, where Z is given by the following formula: Z=1.875×((M1100-M) / M1100)×100% [In the formula, when the silicon-carbon composite is heated in air from about 25°C to about 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C, both measured by thermogravimetric analysis.] Represented by; and iv. φ greater than or equal to 0.1, where φ is given by the following formula: φ = (Maximum peak height dQ / dV in Regime I) / (Maximum peak height dQ / dV in Regime III) [In the formula, dQ / dV is measured in a half-cell coin cell, with Regime I being 0.8V to 0.4V and Regime III being 0.15V to 0V.] Represented by, A hydrosilylated passivated silicon-carbon composite material containing this material.

43. A method for producing chemical vapor-passivated silicon-carbon composite particles, the following: d. To provide carbon scaffold particles containing pore volume having more than 70% microporosity; e. Manufacturing silicon-carbon composite particles by contacting porous carbon scaffold particles with silane gas at 350°C to 550°C; and f. Contacting the silicon-carbon composite particles with alkyne gas at 300°C to 700°C to produce chemically vapor-passivated silicon-carbon composite particles; and g. The silicon-carbon composite contains φ of 0.1 or greater, where φ is given by the following formula: φ = (Maximum peak height dQ / dV in Regime I) / (Maximum peak height dQ / dV in Regime III) [In the formula, dQ / dV is measured in a half-cell coin cell, with Regime I being 0.8V to 0.4V and Regime III being 0.15V to 0V.] Represented by, A manufacturing method that includes this.

44. A chemical vapor-passivated silicon-carbon composite material, the following: a. Carbon scaffolds containing pore volume with over 70% microporosity; b. Nano-sized silicon domains within the pores of porous carbon, where the silicon surface contains Si-H bonds; c. A carbonaceous layer covering at least partially the silicon domain; and d. Chemical vapor-passivated silicon-carbon composites are as follows: i. Silicon content of 30% to 60% by weight; ii. 30m ２ Surface area less than / g; iii. Z less than 10, where Z is given by the following formula: Z=1.875×((M1100-M) / M1100)×100% [In the formula, when the silicon-carbon composite is heated in air from about 25°C to about 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C, both measured by thermogravimetric analysis.] Represented by; and iv. φ greater than or equal to 0.1, where φ is given by the following formula: φ = (Maximum peak height dQ / dV in Regime I) / (Maximum peak height dQ / dV in Regime III) [In the formula, dQ / dV is measured in a half-cell coin cell, with Regime I being 0.8V to 0.4V and Regime III being 0.15V to 0V.] Represented by, A chemical vapor-passivated silicon-carbon composite material containing,

45. A method for producing chemically vapor-passivated silicon-carbon composite particles, the following: d. To provide carbon scaffold particles containing pore volume having more than 70% microporosity; e. Manufacturing silicon-carbon composite particles by contacting porous carbon scaffold particles with silane gas at 350°C to 550°C; and f. Contacting the silicon-carbon composite particles with acetylene gas at 300°C to 700°C to produce chemically vapor-passivated silicon-carbon composite particles; and g. The silicon-carbon composite contains φ of 0.1 or greater, where φ is given by the following formula: φ = (Maximum peak height dQ / dV in Regime I) / (Maximum peak height dQ / dV in Regime III) [In the formula, dQ / dV is measured in a half-cell coin cell, with Regime I being 0.8V to 0.4V and Regime III being 0.15V to 0V.] Represented by, A manufacturing method that includes this.

46. A chemical vapor-passivated silicon-carbon composite material, the following: a. Carbon scaffolds containing pore volume with over 70% microporosity; b. Nano-sized silicon domains within the pores of porous carbon, where the silicon surface contains Si-H bonds; c. A carbonaceous layer covering at least partially the silicon domain; and d. Chemical vapor-passivated silicon-carbon composites are as follows: i. Silicon content of 30% to 60% by weight; ii. 30m ２ Surface area less than / g; iii. Z less than 10, where Z is given by the following formula: Z=1.875×((M1100-M) / M1100)×100% [In the formula, when the silicon-carbon composite is heated in air from about 25°C to about 1100°C, M1100 is the mass of the silicon-carbon composite at 1100°C, and M is the minimum mass of the silicon-carbon composite between 800°C and 1100°C, both measured by thermogravimetric analysis.] Represented by; and iv. φ greater than or equal to 0.1, where φ is given by the following formula: φ = (Maximum peak height dQ / dV in Regime I) / (Maximum peak height dQ / dV in Regime III) [In the formula, dQ / dV is measured in a half-cell coin cell, with Regime I being 0.8V to 0.4V and Regime III being 0.15V to 0V.] Represented by, including, A chemical vapor-passivated silicon-carbon composite material containing this material.

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