Systems and methods for disproportionation of silicon oxide for anode materials

Abstract

The present disclosure is directed to systems and methods of producing disproportionated silicon oxide composite particles. The disproportionated silicon monooxide composite particles can be produced by mixing an alkali metal salt and / or an alkaline earth metal salt, a carbon precursor, a liquid medium, and silicon monooxide particles to form a precursor suspension. The precursor suspension can be heated to form a powder that includes disproportionated silicon monooxide particles having a coating comprising alkali metal and / or alkaline earth metal, wherein the disproportionation of the silicon monoxide is at least 30%.

Description

SYSTEMS AND METHODS FOR DISPROPORTIONATION OF SILICON OXIDE FOR ANODE MATERIALS FIELD

[0001] This disclosure relates to systems and methods for the disproportionation of silicon oxide. More specifically, this disclosure relates to systems and methods for driving the disproportionation of silicon monoxide to be used as an anode material. BACKGROUND

[0002] Silicon and silicon oxides are often used as anode active materials in lithium-ion batteries to improve the energy density of the batteries. However, in the first cycle of a lithium-ion battery, there can be irreversible loss of the active lithium from the cathode and / or electrolyte believed to be caused by the reaction of silicon or silicon oxide with lithium. To address this issue, silicon oxide can be pre-doped with lithium to form lithium silicates that do not contribute to the charging / discharging and therefore improve the first cycle charge / discharge coulombic efficiency. SUMMARY

[0003] Described herein are systems and methods of producing disproportionated silicon oxide composite particles that can be used as an anode material. Specifically, the methods disclosed herein can control the disproportionation of silicon monoxide to silicon dioxide and elemental silicon in order to produce silicon oxide particles with a high degree of disproportionation of SiO and a high degree of crystallization of the resultant silicon dioxide. The controlled generation of these disproportionated silicon oxide particles can be facilitated by alkali metal salts and / or alkaline earth salts in conjunction with relatively high temperature processing. These disproportionated silicon oxide particles can have a high crystalline phase content as well as can exhibit a first cycle Coulombic efficiency (“1CE”).

[0004] Reaction of silicon oxide with alkali metal salts and / or alkaline earth metal salts can enable the formation of a new composite material / particles that includes elemental nano meter silicon and nano meter crystalline SiO2. The new composite material / particles can yield a much improved first cycle efficiency over either non-disproportionated SiO or partially disproportionated SiO without extensive SiO2crystallization.

[0005] In some embodiments, a method of producing a powder includes mixing an alkali metal salt and / or an alkaline earth metal salt, a liquid medium, and silicon monoxideAttorney Docket No.: L3-8121 WO particles to form a precursor suspension; heating the precursor particles to form a powder comprising disproportionated silicon monoxide particles having a coating comprising alkali metal and / or alkaline earth metal, wherein the disproportionation of the silicon monoxide is at least 30%. In some embodiments, the alkali metal salt is a non-lithium alkali metal salt. In some embodiments, the non-lithium alkali metal salt is sodium hydroxide or sodium carbonate. In some embodiments, the method includes mixing a carbon precursor with the alkali metal salt and / or an alkaline earth metal salt, the liquid medium, and the silicon monoxide particles to form the precursor suspension. In some embodiments, the carbon precursor comprises pentane, hexane, 2-methylhexane, cyclopentane, cyclohexane, methylcyclohexane, heptane, 4-methylheptane, octane, cyclooctane, nonane, decane, benzene, toluene, xylene, ethylbenzene, amylbenzene, methylethylbenzene, diethylbenzene, mesitylene, 1,2,4-triethylbenzene, 1,3,5-triethylbenzene, amylbenzene, tetrahydronaphthalene, refinery heavy oil, pitch, polyethylene, polypropylene, polyacrylic acid, polymaleic acid, polyfumaric acid, polycrotonic acid, poly(pentenoic) acid, polymethacrylic acid, polydimethacrylic acid, poly(allyl alcohol), poly(n-propyl)acrylate, poly(hydroxymethyl)acrylate, poly(2-hydroxyethyl)acrylate, poly(2-carboxyethyl)acrylate, poly(3-ethoxy-3-oxopropyl)acrylate, poly(methylcarbamylethyl)acrylate, poly(2- hydroxyethyl)methacrylate, polyvinylpyrrolidone, polyacrylamide, polymethacrylamide, poly(N-isopropyl)acrylamide, polyvinylacetamide, polyvinyl alcohol, polyvinyl-N- methylacetamide, poly(N-hydroxymethyl)acrylamide, poly(N-hydroxyethyl)acrylamide, poly(N-methoxymethyl)acrylamide, poly(N-ethoxymethyl)acrylamide, polyacrylonitrile, sucrose, natural polymers such as cellulose and polysaccharides, or combinations thereof. In some embodiments, the liquid medium comprises water, alcohols, esters, ketones, nitriles, halogenated hydrocarbons, or combinations thereof. In some embodiments, the silicon monoxide particles comprise carbon coated silicon monoxide particles. In some embodiments, the precursor suspension is heated to 700-1000oC. In some embodiments, the precursor particles are heated in an inert environment comprising an inert gas. In some embodiments, the powder has an amorphous content of less than 60%. In some embodiments, the powder has a silicon crystallite size of less than 125 nm.

[0006] In some embodiments, a powder includes disproportionated silicon monoxide particles having a coating comprising carbon and an alkali metal and / or alkaline earth metal, wherein the powder has an amorphous content of less than 60%. In some embodiments, the powder has a silicon crystallite size of less than 125 nm. In some embodiments, the alkaliAttorney Docket No.: L3-8121 WO metal is a non-lithium alkali metal. In some embodiments, the non-lithium alkali metal is sodium.

[0007] In some embodiments, an anode can include any of the powder above or disclosed herein. In some embodiments, a battery can include the anode. In some embodiments, the battery can be a lithium-ion battery.

[0008] It will be appreciated that any of the variations, aspects, features and options described in view of the systems, methods, and / or powders apply equally to the systems, methods, powders, other devices / configurations, and vice versa. It will also be clear that any one or more of the above variations, aspects, features and options can be combined.

[0009] Additional advantages will be readily apparent to those skilled in the art from the following detailed description. The aspects and descriptions herein are to be regarded as illustrative in nature and not restrictive.

[0010] All publications, including patent documents, scientific articles and databases, referred to in this application are incorporated by reference in their entirety for all purposes to the same extent as if each individual publication were individually incorporated by reference. If a definition set forth herein is contrary to or otherwise inconsistent with a definition set forth in the patents, applications, published applications and other publications that are herein incorporated by reference, the definition set forth herein prevails over the definition that is incorporated herein by reference. BRIEF DESCRIPTION OF THE FIGURES

[0011] The disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0012] FIG. 1 illustrates an example of a composite particle production process in accordance with some embodiments disclosed herein.

[0013] FIG.2A illustrates the results of x-ray diffraction of Example 1 in accordance with some embodiments disclosed herein.

[0014] FIG.2B illustrates the results of x-ray diffraction of Example 2 in accordance with some embodiments disclosed herein.

[0015] FIG.2C illustrates the results of x-ray diffraction of Example 3 in accordance with some embodiments disclosed herein.

[0016] FIG. 3 illustrates an example of how to calculate amorphous content from x-ray diffraction in accordance with some embodiments disclosed herein.Attorney Docket No.: L3-8121 WO DETAILED DESCRIPTION

[0017] Reference will now be made in detail to implementations and embodiments of various aspects and variations of devices, powders, systems, and methods described herein. Although several exemplary variations of the devices, powders, systems, and methods are described herein, other variations of the devices, powders, systems, and methods may include aspects of the devices, powders, systems, and methods described herein combined in any suitable manner having combinations of all or some of the aspects described.

[0018] Silicon monoxide (SiO) is an amorphous material consisting of nano cluster of elemental silicon (Si or Si0) and silicon dioxide (SiO2). Silicon monoxide can be used as a negative electrode material (in lithium ion batteries) because it has a high capacity (approximately 2600 mAh / g). However silicon monoxide can have a low initial Coulombic efficiency (approximately 76%) and this low Coulombic efficiency can preclude its commercial use in lithium-ion batteries as a high Coulombic efficiency can be desired to maximize utilization of the limited lithium content provided from the cathode material in a typical lithium-ion battery.

[0019] To overcome the low Coulombic efficiency of silicon oxide, prelithiation is typically instituted. Prelithiation is a common chemical or electrochemical process in which the silicon oxide is reacted with a lithium containing component prior to installation in a battery to offset the low Coulombic efficiency. In a typical process to create prelithiated silicon particles such as that described in PCT App. No. PCT / US2019 / 055980 (which is hereby incorporated by reference in its entirety), a paste of a carbon precursor, solvent, a lithium precursor, and silicon oxide is heated / reacted to form a composite material with a silicon core and a shell of carbon and lithium silicates (e.g., (Li2Si2O5, Li2SiO3, and / or Li4SiO4).

[0020] Described herein are systems and methods of producing disproportionated silicon oxide powder or particles with high Coulombic efficiency. Pristine silicon monoxide (SiO) can consist of both silicon (Si) and silicon dioxide (SiO2) with these components being amorphous and made up of infinitely small (e.g., < 5 nm) domains that may not exhibit long range crystallographic order. Disproportionation can describe the bulk crystallization of these domains into two or more crystallographically distinct entities (e.g., Si, cristobalite SiO2, quarts SiO2, etc.). The disproportionation of SiO is a thermodynamically favorable process, but may be kinetically sluggish often requiring temperatures of greater than 1400oC to be driven forward. In addition, at these high temperatures, the silicon crystallite size may be too large (e.g., 100 nm or greater) such that its performance as an anode material can deteriorate. For example, at a high temperature (e.g., greater than 1400oC) the silicon phaseAttorney Docket No.: L3-8121 WO may be made up of very large crystals that are embedded in a crystalline SiO2 matrix that may not allow lithium in and / or out when used in a battery. Instead, lower silicon crystallite sizes can be preferred and lower temperatures can prevent silicon crystalline growth. As disclosed by the methods and systems herein, the average silicon crystallite size can be less than about 100 nm, less than about 90 nm, less than about 80 nm, less than about 75 nm, less than about 50 nm, or less than about 25 nm. In some embodiments, the average silicon crystallite sizes disclosed herein can be greater than about 1 nm, greater than about 5nm, or greater than about 10 nm

[0021] Applicant has discovered that the addition of an alkali metal salt and / or alkaline earth metal salt during the heating / reaction (e.g., calcination) step of silicon oxide (e.g., SiO) can significantly lower the temperature needed for SiO disproportionation, thereby allowing the generation of high performance materials (e.g., anode materials).

[0022] FIG.1 illustrates process 100 for forming disproportionated silicon oxide composite particles 108 as disclosed herein. To form the composite particles, a precursor suspension 103 can be formed. In some embodiments, the precursor suspension 103 can be formed by mixing one or more alkali metal salts and / or alkaline earth metal salts 101a, one or more carbon precursors 101b, and / or one or more liquid mediums 101c with silicon oxide particles 102. In some embodiments, the precursor suspension can be formed in a mixer. In some embodiments, the mixing can include a magnetic stirrer, an overhead stirrer, an acoustic mixer (e.g., a high frequency acoustic mixer) and / or a shaker, among others. In some embodiments, the one or more alkali metal salts and / or alkaline earth metal salts and / or the one or more carbon precursors can be dissolved, suspended, dispersed, slurried, and / or emulsified in the one or more liquid mediums to form the precursor suspension. In some embodiments, one or more carbon precursors may not be added to the precursor suspension.

[0023] In some embodiments, the alkali metal salts and / or alkaline earth metal salts can be any alkali metal salt and / or any alkaline earth metal salt. In some embodiments, the alkali metal can be lithium, sodium, potassium, rubidium, cesium, and / or francium. In some embodiments, the alkaline earth metal can be beryllium, magnesium, calcium, strontium, barium, and / or radium. In some embodiments, the alkali metal is a non-lithium alkali metal. In other words, the alkali metal salt may not include lithium. In some embodiments, the alkali metal salts and / or alkaline earth metal salt can be a hydroxide, carbonate, phosphate, sulfate, acetate, cyanide, chloride, bromide, iodide, chlorate, bicarbonate, nitrite, nitrate, sulfite, acetylacetate, benzoate, citrate, formate, oxalate, oxide, salicylate, tartrate,Attorney Docket No.: L3-8121 WO phosphite, sulfide, and / or silicate. In some embodiments, hydrated forms of these alkali metal salts and / or alkaline earth metal salts can also be used. In some embodiments, the alkali metal salt can be lithium hydroxide, lithium carbonate, sodium hydroxide, and / or sodium carbonate. In some embodiments, the alkali metal salts and / or alkaline earth metal salts can be in the form of a powder.

[0024] In some embodiments, the amount of alkali metal salts and / or alkaline earth metal salts in the precursor suspension can be an amount that the total weight percent of the alkali metal salt and / or alkaline earth metal salt in the precursor suspension can be about 0.01-15 wt.%, about 0.05-10 wt.%, about 0.1-5 wt.%, about 0.1-4.5 wt.%. In some embodiments, the amount of alkali metal salts and / or alkaline earth metal salts in the precursor suspension can be an amount that the total weight percent of the alkali metal salt and / or alkaline earth metal salt in the precursor suspension can be at least about 0.01 wt.%, at least about 0.05 wt.%, at least about 0.1 wt.%, at least about 0.5 wt.%, at least about 1 wt.%, at least about 2 wt.%, at least about 3 wt.%, or at least about 4 wt.%. In some embodiments, the amount of alkali metal salts and / or alkaline earth metal salts in the precursor suspension can be an amount that the total weight percent of the alkali metal salt and / or alkaline earth metal salt in the precursor suspension can be at most about 15 wt.%, at most about 10 wt.%, at most about 8 wt.%, at most about 6 wt.%, at most about 5 wt.%., at most about 4.5 wt.%, at most about 4 wt.%, at most about 3 wt.%, at most about 2 wt.%, at most about 1 wt.%, or at most about 0.5 wt.%.

[0025] In some embodiments, the amount of alkali metal and / or alkaline earth metal in the precursor suspension can be an amount that the total weight percent of the alkali metal and / or alkaline earth metal in the precursor suspension can be about 0.001-5 wt.%, about 0.005-2 wt.%, about 0.01-1 wt.%, or about 0.01-0.75 wt.%. In some embodiments, the amount of alkali metal and / or alkaline earth metal in the precursor suspension can be an amount that the total weight percent of the alkali metal and / or alkaline earth metal in the precursor suspension is at least about 0.001 wt.%, at least about 0.005 wt.%, at least about 0.01 wt.%, at least about 0.02 wt.%, at least about 0.05 wt.%, at least about 0.1 wt.%, at least about 0.25 wt.%, at least about 0.5 wt.%, or at least about 0.7 wt.%. In some embodiments, the amount of alkali metal and / or alkaline earth metal in the precursor suspension can be an amount that the total weight percent of the alkali metal and / or alkaline earth metal in the precursor suspension is at most about 5 wt.%, at most about 2.5 wt.%, at most about 2 wt.%, at most about 1 wt.%, at most about 0.8 wt.%, at most about 0.75 wt.%,Attorney Docket No.: L3-8121 WO at most about 0.5 wt.%, at most about 0.25 wt.%, at most about 0.1 wt.%, or at most about 0.05 wt.%.

[0026] In some embodiments, the amount of alkali metal salts and / or alkaline earth metal salts in the precursor suspension can be an amount that the total moles of the alkali metal and / or alkaline earth metal in the precursor suspension can be about 0.5-4.6 mol / kg precursor suspension. In some embodiments, the amount of alkali metal salts and / or alkaline earth metal salts in the precursor suspension can be an amount that the total moles of the alkali metal and / or alkaline earth metal in the precursor suspension can be less than 10, less than 7, less than 5, less than 4.6, less than 4, less than 3, less than 2.5, less than 2, less than 1.5, or less than 1 mol / kg precursor suspension. In some embodiments, the amount of alkali metal salts and / or alkaline earth metal salts in the precursor suspension can be an amount that the total moles of the alkali metal and / or alkaline earth metal in the precursor suspension can be greater than 0.1, greater than 0.5, greater than 1, greater than 1.5, greater than 2, greater than 2.5, greater than 3, greater than 3.5, greater than 4, or greater than 4.5 mol / kg precursor suspension.

[0027] In some embodiments, the carbon precursors can be hydrocarbons (e.g., contain only carbon and hydrogen), organic compounds that contain one or more heteroatoms (e.g., oxygen and / or nitrogen), or combinations thereof. In some embodiments, the carbon precursors can have higher amounts of carbon relative to hydrogen (e.g., aromatic compounds). In some embodiments, the carbon precursors can be polymers, including polyolefins, heteroatom-containing polymers, or combinations thereof. In some embodiments, the carbon precursors can include pentane, hexane, 2-methylhexane, cyclopentane, cyclohexane, methylcyclohexane, heptane, 4-methylheptane, octane, cyclooctane, nonane, decane, benzene, toluene, xylene, ethylbenzene, amylbenzene, methylethylbenzene, diethylbenzene, mesitylene, 1,2,4-triethylbenzene, 1,3,5- triethylbenzene, amylbenzene, tetrahydronaphthalene, refinery heavy oil, pitch, polyethylene, polypropylene, polyacrylic acid, polymaleic acid, polyfumaric acid, polycrotonic acid, poly(pentenoic) acid, polymethacrylic acid, polydimethacrylic acid, poly(allyl alcohol), poly(n-propyl)acrylate, poly(hydroxymethyl)acrylate, poly(2- hydroxyethyl)acrylate, poly(2-carboxyethyl)acrylate, poly(3-ethoxy-3-oxopropyl)acrylate, poly(methylcarbamylethyl)acrylate, poly(2-hydroxyethyl)methacrylate, polyvinylpyrrolidone, polyacrylamide, polymethacrylamide, poly(N-isopropyl)acrylamide, polyvinylacetamide, polyvinyl alcohol, polyvinyl-N-methylacetamide, poly(N- hydroxymethyl)acrylamide, poly(N-hydroxyethyl)acrylamide, poly(N-Attorney Docket No.: L3-8121 WO methoxymethyl)acrylamide, poly(N-ethoxymethyl)acrylamide, polyacrylonitrile, sucrose, natural polymers such as cellulose and polysaccharides, or combinations thereof.

[0028] As stated above, the liquid medium can be a liquid such that the one or more alkali metal salts and / or alkaline earth metal salts and / or the one or more carbon precursors can be dissolved, suspended, dispersed, slurried, and / or emulsified in the liquid medium to form the precursor suspension. In some embodiments, the liquid medium can be a liquid such that the one or more alkali metal salts and / or alkaline earth metal salts, the one or more silicon oxide particles, and / or the one or more carbon precursors can be dissolved, suspended, dispersed, slurried, or emulsified in the liquid medium to form the precursor suspension. In some embodiments, the one or more alkali metal salts and / or alkaline earth metal salts and / or the one or more carbon precursors can be in different states in the liquid medium. For example, the alkali metal salts and / or alkaline earth metal salts may be dissolved in the liquid medium, whereas the carbon precursor can be suspended in the liquid medium.

[0029] In some embodiments, the amount of carbon precursor in the precursor suspension can be an amount such that the carbon precursor(s) is slurried or dissolved in the liquid medium. In some embodiments, the amount of carbon precursor(s) in the precursor suspension can be about 0.01-15 wt.%, about 0.1-5 wt.%, or about 0.5-2 wt.%. In some embodiments, the amount of carbon precursor(s) in the precursor suspension can be at least about 0.01 wt.%, at least about 0.25 wt.%, at least about 0.5 wt.%, at least about 0.6 wt.%, at least about 0.7 wt.%, at least about 0.75 wt.%, at least about 1 wt.%, at least about 5 wt.%, or at least about 10 wt.%. In some embodiments, the amount of carbon precursor(s) in the precursor suspension can be at most about 15 wt.%, at most about 10 wt.%, at most about 5 wt.%, at most about 2.5 wt.%, at most about 2 wt.%, at most about 1 wt.%, at most about 0.9 wt.%, at most about 0.85 wt.%, or at most about 0.8 wt.%.

[0030] In some embodiments, the liquid medium can include one or more solvents. In some embodiments, the alkali metal salts and / or alkaline earth metal salts can be in one or more solvents, whether dissolved, suspended, dispersed, slurried, and / or emulsified, and the carbon precursor can separately be in one or more solvents, whether dissolved, suspended, dispersed, slurried, and / or emulsified, and the alkali metal salts and / or alkaline earth metal salts in its solvent(s) can be combined with the carbon precursor in its solvent(s) to form the precursor suspension. In some embodiments, the alkali metal salts and / or alkaline earth metal salts may have at least some ionic character and a polar solvent can be used as the one or more liquid mediums. In some embodiments, the carbon precursor may have limitedAttorney Docket No.: L3-8121 WO solubility in a polar solvent, and can be dissolved in a nonpolar solvent to form a solution of the carbon precursor, which can then be combined with a solution of the alkali metal salts and / or alkaline earth metal salts to obtain the precursor suspension comprising the liquid mediums and the carbon precursor and alkali metal salts and / or alkaline earth metal salts. In some embodiments, when the carbon precursor is dissolved in a nonpolar solvent, the nonpolar solvent can have some miscibility with the polar solvent in which the alkali metal salt and / or alkaline earth metal salt may be dissolved. In some embodiments, in a precursor suspension in which the alkali metal salts and / or alkaline earth metal salts and / or the carbon precursor are suspended, partially dissolved, slurried, emulsified, and / or dispersed, the coating formed from such precursor suspension may be less uniform; however, such precursor suspensions may provide other advantages such as ease of transfer.

[0031] In some embodiments, the liquid medium can include a polar solvent, a nonpolar solvent, or a combination thereof. In some embodiments, the polar solvent(s) can be protic or aprotic. In some embodiments, the liquid medium can include mixtures of polar solvents including mixtures comprising an aprotic solvent and a protic solvent. In some embodiments, the polar solvent(s) can include water, alcohols, esters, ketones, nitriles, halogenated hydrocarbons, or combinations thereof. In some embodiments, the polar solvent(s) can include water, methanol, ethanol, n-propanol, 2-propanol, 1-butanol, 2- methyl-1-propanol, 1-methyl-1-propanol, cyclopropylmethanol, cyclobutanol, cyclopentanol, acetonitrile, propionitrile, hexanenitrile, benzonitrile, acetone, methyl ethyl ketone, pentanone, hexanone, heptanone, tetrahydrofuran, diethyl ether, di-n-propyl ether, diisopropyl ether, di-n-butyl ether, butyl ethyl ether, cyclohexylmethyl ether, tetrahydrofuran, tetrahydropyran, 1,3-dioxane, 1,4-dioxane, 1,3-dioxolane, ethylene glycol, diethylene glycol, ethyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, amyl acetate, hexyl acetate, methyl propionate, ethyl propionate, ethyl butyrate, ethyl benzoate, dichloromethane, dibromomethane, dibromoethane, trichloromethane, tribromomethane, 1,2-dichloroethane, chlorobenzene, bromobenzene, dimethylformamide, dimethylsulfoxide, N-methyl pyrrolidinone, or combinations thereof. In some embodiments, nonpolar solvent(s) can include liquid aromatic hydrocarbons liquid aliphatic hydrocarbons, or combinations thereof. In some embodiments, liquid hydrocarbons can include pentane, hexane, 2-methylhexane, cyclopentane, cyclohexane, methylcyclohexane, heptane, 4-methylheptane, octane, cyclooctane, nonane, decane, benzene, toluene, xylene(s), ethylbenzene, mesitylene, methylethylbenzene, diethylbenzene, cumene, cymene, tetrahydronaphthalene, or combinations thereof. In some embodiments, if theAttorney Docket No.: L3-8121 WO liquid medium includes one or more carbon-containing components / solvents, some of the carbon from these components / solvents may become part of the coating on the composite particles.

[0032] In some embodiments, the amount of liquid medium in the precursor suspension can be about 10-95 wt.%, about 20-90 wt.%, about 30-90 wt.%, or about 40-85 wt.%. In some embodiments, the amount of liquid medium in the precursor suspension is at least about 10 wt.%, at least about 20 wt.%, at least about 30 wt.%, at least about 40 wt.%, at least about 50 wt.%, at least about 60 wt.%, at least about 70 wt.%, at least about 75 wt.%, at least about 80 wt.%, or at least about 81 wt.%. In some embodiments, the amount of liquid medium in the precursor suspension is at most about 95 wt.%, at most about 90 wt.%, or at most about 85 wt.%.

[0033] In some embodiments, the silicon oxide particles 102 can be added to form the precursor suspension 103. In some embodiments, the precursor suspensions can be formed in a mixer. In some embodiments, a precursor suspension can be formed by mixing the one or more alkali metal salts and / or alkaline earth metal salts, one or more carbon precursors, one or more liquid mediums, and / or the silicon oxide particles.

[0034] In some embodiments, the silicon oxide particles include silicon, silicon oxides, or combinations thereof. In some embodiments, the silicon oxide particles are at least about 95 wt.%, at least about 98 wt.%, or at least about 99 wt.% silicon, neglecting impurities where impurities are elements other than silicon and oxygen. In some embodiments, the silicon oxides are of the formula SiOxwhere x is about 0.75-2, about 0.9-1.8, or about 0.9- 1.5. In some embodiments, the silicon oxide particles include SiO, SiO2, Si, or combinations thereof. In some embodiments, the silicon oxide particles include at least about 95 wt.%, at least about 98 wt.%, or at least about 99 wt.%, silicon oxides, neglecting impurities where impurities are elements other than silicon and oxygen. In some embodiments, the silicon oxide particles can include mixtures of different silicon oxides. In some embodiments, the mixtures of different silicon oxides can be in separate particles and / or particles in which different silicon oxides are present in the same particle. In some embodiments, the silicon oxide particles can be silicon monoxide (SiO) particles.

[0035] In some embodiments, the silicon oxide particles can be coated silicon oxide particles. In some embodiments, the silicon oxide particles can have a carbon coating (e.g., the silicon oxide particles have been subjected to a carbonization surface treatment). For example, in some embodiments, the silicon oxide particles can be carbon coated silicon oxides. In some embodiments, having the silicon oxide particles already carbon coated canAttorney Docket No.: L3-8121 WO eliminate using a carbon precursor either in the precursor suspension and / or in the subsequent heating / reacting steps (e.g., hydrocarbon vapor) disclosed in more detail below. In some embodiments, a specific surface area of the carbon coated silicon oxide particles can be about 0.1-10 m2 / g, about 0.5-5 m2 / g, or about 1-3 m2 / g. In some embodiments, the carbon content of the carbon coated silicon oxide particles is about 0.1-15 wt.%, about 0.5- 10 wt.%, or about 1-5 wt.%. In some embodiments, the carbon coated silicon oxide particles can have a silicon oxide core with a carbon coating shell around the core. In some embodiments, the carbon at least partially coats the silicon oxide particles. In some embodiments, the silicon oxide particles have an average particle size of about 0.1-30 microns, about 0.5-20 microns, or about 0.5-10 microns. In some embodiments, the silicon oxide particles have an average particle size of at least about 0.1 microns, at least about 0.5 microns, at least about 1 micron, at least about 2.5 microns, at least about 5 microns, at least about 7.5 microns, at least about 10 microns, or at least about 20 microns. In some embodiments, the silicon oxide particles have an average particle size of at most about 30 microns, at most about 20 microns, at most about 15 microns, at most about 10 microns, at most about 7.5 microns, at most about 5 microns, at most about 2.5 microns, or at most about 1 micron.

[0036] In some embodiments, the precursor suspension includes silicon oxide particles in an amount of about 1-90 wt.%, about 5-80 wt.%, about 10-70 wt.%, or about 10-60 wt.%. In some embodiments, the precursor suspension includes silicon oxide particles in an amount of at least about 1 wt.%, at least about 5 wt.%, at least about 10 wt.%, at least 20 wt.%, at least 30 wt.%, at least 40 wt.%, or at least 50 wt.%. In some embodiments, the precursor suspension includes silicon oxide particles in an amount of at most about 90 wt.%, at most about 80 wt.%, at most about 70 wt.%, at most about 60 wt.%, at most about 50 wt.%, at most about 40 wt.%, at most about 30 wt.%, at most about 25 wt.%, at most about 20 wt.%, or at most about 15 wt.%.

[0037] In some embodiments, the amount of alkali metal salt and / or alkaline earth metal salt to silicon oxide particles in the precursor suspension is such that the alkali metal:SiO molar ratio and / or alkaline earth metal:SiO molar ratio is about 0.001-1, about 0.005-0.5, or about 0.0095-0.342. In some embodiments, the amount of alkali metal salt and / or alkaline earth metal salt to silicon oxide particles in the precursor suspension is such that the alkali metal:SiO molar ratio and / or alkaline earth metal:SiO molar ratio is at least about 0.001, at least about 0.005 at least about 0.0075, at least about 0.009, at least about 0.0095, at least about 0.01, at least about 0.1, at least about 0.2, or at least about 0.3. In some embodiments,Attorney Docket No.: L3-8121 WO the amount of alkali metal salt and / or alkaline earth metal salt to silicon oxide particles in the precursor suspension is such that the alkali metal:SiO molar ratio and / or alkaline earth metal:SiO molar ratio is at most about 1, at most about 0.75, or at most about 0.5.

[0038] In some embodiments, the alkali metal salt and / or alkaline earth metal salt, carbon precursor(s), liquid medium(s), and / or the silicon oxide particles can be mixed together to form a suspension such that the alkali metal salt and / or alkaline earth metal salt, carbon precursor(s), and / or silicon oxide particles are dissolved, suspended, dispersed, slurried, and / or emulsified in the one or more liquid mediums to form the precursor suspension. In some embodiments, the silicon oxide particles can be suspended or dispersed in the precursor suspension (liquid medium of the precursor suspension) and the alkali metal salt and / or alkaline earth metal salt and / or carbon precursor can be slurried or dissolved in the precursor suspension (liquid medium of the precursor suspension).

[0039] In some embodiments, the precursor suspension (e.g., slurry) has a solids content of about of about 1-90 wt.%, about 5-80 wt.%, about 10-70 wt.%, or about 10-60 wt.%. In some embodiments, the precursor suspension (e.g., slurry) has a solids content of greater than about 1%, greater than about 5%, greater than about 20%, greater than about 30%, greater than about 40%, greater than about 45%, greater than about 50%, or greater than about 55%. In some embodiments, the precursor suspension (e.g., slurry) has a solids content of less than about 90%, less than about 80%, less than about 75%, less than about 70%, less than about 65%, or less than about 60%.

[0040] In some embodiments, the precursor suspensions can be formed in ambient air or in a controlled environment such as an inert environment. In some embodiments, the inert atmosphere can exclude water and / or oxygen. In some embodiments, the inert atmosphere can be an argon and / or nitrogen atmosphere. In some embodiments, the alkali metal salt and / or alkaline earth metal salt can be one that mildly reacts or is non-reactive to the one or more carbon precursors, one or more liquid mediums, and / or one or more silicon oxide particles.

[0041] In some embodiments, the precursor suspension can be spray dried to form precursor particles that include the alkali metal and / or alkaline earth metal and the silicon oxide particles. Unlike traditional processing, where the precursor suspension would have to be dried or the solvent would have to evaporated out of the precursor suspension in an oven (e.g., a vacuum oven) to form precursor particles, spray drying can allow for the precursor particles to be formed quickly and continuously without the need for an elongated evaporation step.Attorney Docket No.: L3-8121 WO

[0042] In some embodiments, the spray dryer can be operated such that the inlet has a temperature of about 180-450oC and / or the outlet has a temperature of about 80-250oC. In some embodiments, the heated drying medium for spray drying can be a gas. In some embodiments, the gas can be an inert gas. In some embodiments, the gas can be air or nitrogen. In some embodiments, the spray dryer can be warmed up until the inlet and outlet temperatures are stable. In some embodiments, the precursor suspension can be fed to the spray dryer to make the spray dried precursor particles.

[0043] In some embodiments, the spray dried precursor particles can include the silicon oxide particles, the alkali metal salt and / or alkaline earth metal salt, and / or the carbon precursor(s). In other words, the spray dried precursor particles can be made up of one or more of the silicon oxide particles, alkali metal salt and / or alkaline earth metal salt, and carbon precursor(s). In some embodiments, the spray dried precursor particles can include the silicon oxide particles with the alkali metal salt and / or alkaline earth metal salt and / or carbon precursor(s) attached to the surface of the inorganic particles. In some embodiments, the spray dried precursor particles can be silicon oxide particles coated with the alkali metal salt and / or alkaline earth metal salt and / or carbon precursor(s). In some embodiments, the spray drying can uniformly coat the silicon oxide particles with the alkali metal salt and / or alkaline earth metal salt and / or carbon precursor(s). In some embodiments, no reaction besides drying can take place during the spray drying. In some embodiments, dehydration and / or decomposition of lithium hydroxide monohydride can happen during the spray drying.

[0044] In some embodiments, the precursor suspension (or spray dried precursor particles) can be heated in a reaction step (e.g., calcination) 104 such that disproportionation of the silicon oxide particles can occur. 100% disproportionation of silicon monoxide would be the following Reaction (1), where 2 moles of SiO form 1 mole of Si and 1 mole of SiO2: 2^^^^^^ → ^^^^ ^ ^^^^^^ଶ (1)

[0045] The disproportionation of SiO is quantifiable through the Rietveld method of refining powder x-ray diffraction (PXRD) data collected with a known mass of an internal standard. Originally, PXRD data only indicated the formation of Si, SiO2, and various silicates. PXRD is limited to the observation of crystalline materials, and thus it was believed that typical prelithiation processes drove crystallization to completion with the relative weight ratios of all observed materials adding up to 100%. However, inclusion ofAttorney Docket No.: L3-8121 WO a known quantity of a crystalline material with a known structure can allow the absolute weight ratios of all crystalline materials to be quantified, with the missing mass being attributable to remnant amorphous material in the composite.

[0046] Complete disproportionation of Reaction (1) would result in a product that includes 31.8% Si by mass and 68.2% SiO2 by mass. The actual disproportionation of this reaction step (e.g., calcination) can be referenced to Reaction (1), where the observed formation of Si can be compared to the possible maximum formation of Si. For example, if a Rietveld refinement containing an internal standard indicates the formation of 25.44% Si by weight, then disproportionation in the reaction can be calculated by 25.44 / 31.8 = 0.8, or 80% disproportionation. The Rietveld method is a least-squares fitting technique that quantifies the crystalline components observed via PXRD A high degree of disproportionation can be beneficial to generate a large portion of elemental silicon as this elemental silicon can function as the primary source for reversible lithium ion storage in an anode.

[0047] Besides a high degree of disproportionation, the generation of crystalline SiO2(cSiO2) over amorphous SiO2 (αSiO2) can increase the Coulombic efficiency of the resulting composite particles. For example, consider Reactions (2) and (3): 2^^^^^^ → ^^^^ ^ ^^^^^^^^ଶ (2)2 ^^^^^^ → ^^^^ ^ ^^^^^^^^ଶ (3)

[0048] Both reactions can exhibit 100% disproportionation, producing 1 mole of Si and 1 mole of SiO2. However, in Reaction (2), all SiO2 is amorphous yielding an amorphous content of 68.2%. In contrast, all SiO2in Reaction (3) is crystalline, and thus the products are 0% amorphous. If products of Reactions (2) and (3) were installed in an electrode for lithium ion storage, the crystalline products of Reaction (3) would be expected to have a significantly higher Coulombic efficiency than the mixed amorphous and crystalline products of Reaction (2). As such, the disproportionation of SiO and the subsequent crystallization of the products (as well as Si crystalline size) can impact the Coulombic efficiency of the composite particles disclosed herein.

[0049] Applicant has discovered that the disproportionation of SiO and crystallization of the products of the disproportionation reaction can be facilitated / driven by its reaction with alkali metal salts and / or alkaline earth metal salts. The amount of alkali metal and / or alkaline earth metal as well as the reaction (e.g., calcination) temperature can impact the degree of disproportionation and the amount of amorphous content. Specifically, reaction conditions can be controlled to maximize the Coulombic efficiency of the compositeAttorney Docket No.: L3-8121 WO particles which can arise from composite particles with a low amorphous content of the disproportionated SiO. In addition, as stated above, the smaller the Si crystalline size, the more effective the material can be as an anode material. The Si crystallite size can be measured using x-ray diffraction.

[0050] Previously, it was believed that the formation of lithium silicates were a necessary component for enabling the performance of an anode material made with prelithiated SiO. However, Applicant discovered that using a non-lithium alkali metal or an alkaline earth metal can simulate prelithiated composite particles without the use of lithium compounds for use in an anode of a lithium-ion battery.

[0051] In some embodiments, the precursor suspension (or spray dried precursor particles) is heated to at least about 500oC, at least about 550oC, at least about 600oC, at least about 650oC, at least about 700oC, at least about 750oC, at least about 800oC, at least about 850oC, at least about 900oC, or at least about 950oC. In some embodiments, the precursor suspension is heated to at most about 1200oC, at most about 1150oC, at most about 1100oC, at most about 1050oC, or at most about 1000oC. In some embodiments, the precursor suspension is heated to about 500-1200oC, about 600-1100oC, or about 700-1000oC. In some embodiments, the precursor suspension is heated for about 0.1-10 hours, about 0.2-5 hours, about 0.5-4 hours, 0.5-3 hours, or about 1-3 hours.

[0052] In some embodiments, the heating / reacting of the precursor suspension is performed in an inert environment to form the final powder. In some embodiments, the inert environment can be static or a flow of the inert gas or inert gases in the inert environment. In some embodiments, the inert environment can include argon, nitrogen, helium, or combinations thereof.

[0053] In some embodiments, the reacting / heating step can cause disproportionated silicon oxide composite particles 108 to form. In some embodiments, the reacting / heating step can cause the silicon oxide particles to react with the alkali metal and / or alkaline earth metal to form silicates. In some embodiments, the composite particles can include disproportionated silicon oxide particles that have a coating comprising carbon and / or one or more of alkali metal and / or alkaline earth metal. In some embodiments, the composite particles can include disproportionated silicon oxide particles that have a coating comprising carbon and / or one or more of alkali metal silicates and / or alkaline earth metal silicates. For example, in some embodiments, the composite particles can include the carbon coated disproportionated silicon oxide particles that have one or more alkali metals and / or alkaline earth metals (and / or silicates thereof) with one or more calcined carbons on the surface ofAttorney Docket No.: L3-8121 WO the carbon coated disproportionated silicon oxide particles. In addition, in some embodiments, there can be multiple coatings or multiple coating layers on the surface of the carbon coated particles.

[0054] In some embodiments, the disproportionated silicon oxide particles of the composite particles can be the products of the disproportionation reaction. In some embodiments, the disproportionated silicon oxide particles of the composite particles can include Si and crystalline SiO2. In some embodiments, the disproportionated silicon oxide particles can be material derived from SiO in which some or all of the Si and some or all of the SiO2has crystallized.

[0055] In some embodiments, this heating / reaction step can take place in a reactor such as a stationary, tube, or rotary kiln or furnace.

[0056] In some embodiments, the disproportionation of the silicon monoxide in the reaction / heating step can be about 5-100%, about 20-90%, or about 30-90%. In some embodiments, the disproportionation of the silicon monoxide in the reaction / heating step can be at least about 5%, at least about 10%, at least about 20%, at least about 30%, at least about 40%, least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, or at least about 85%. In some embodiments, the disproportionation of the silicon monoxide in the reaction / heating step can be at most about 100%, at most about 99%, at most about 98%, at most about 95%, at most about 90%, at most about 85%, at most about 80%, or at most about 75%.

[0057] In some embodiments, the amorphous content of the composite particles (powder) can be about 5-90%, about 10-80%, or about 15-60%. In some embodiments, the amorphous content of the composite particles (powder) can be less than about 90%, less than about 80%, less than about 75%, less than about 70%, less than about 65%, less than about 60%, less than about 55%, less than about 50%, less than about 45%, less than about 40%, less than about 35%, less than about 30%, less than about 25%, less than about 20%, less than about 15%, less than about 10%, or less than about 5%. In some embodiments, the amorphous content of the composite particles (powder) can be more than about 5%, more than about 10%, more than about 15 %, more than about 20%, more than about 25%, more than about 30%, more than about 35%, more than about 40%, or more than about 45%.

[0058] In some embodiments, the Si crystallite size of the composite particles (powder) can be about 0.1-200 nm, about 1-150 nm, or about 5-120 nm. In some embodiments, the Si crystallite size of the composite particles (powder) can be at most about 200 nm, at most about 150 nm, at most about 125 nm, at most about 120 nm, at most about 100 nm, at mostAttorney Docket No.: L3-8121 WO about 75 nm, at most about 50 nm, at most about 40 nm, at most about 35 nm, at most about 30 nm, at most about 25 nm, at most about 20 nm, at most about 15 nm, or at most about 10 nm. In some embodiments, the Si crystallite size of the composite particles (powder) can be at least about 0.1 nm, at least about 1 nm, at least about 5 nm, at least about 10 nm, at least about 15 nm, at least about 25 nm, at least about 30 nm, at least about 35 nm, at least about 50 nm, or at least about 75 nm.

[0059] In some embodiments, the composite particles can be cooled after the reaction / heating step. In some embodiments, the composite particles can be cooled in an inert atmosphere such as one of the inert atmospheres used during the reaction / heating step. In some embodiments, the composite particles can be washed (after cooling) with one or more liquid mediums (as described above) to remove any unreacted precursors and / or undesired by-products.

[0060] In some embodiments, the composite particles can be ground, milled, or other techniques to a desired particle size distribution after the heating / reaction step (or cooling step). In some embodiments, after the heating / reaction step or after the grinding step, the composite particles can be sieved. For example, the composite powder can be seived through a 325 mesh.

[0061] As stated above, the composite particles or powder can include disproportionated silicon oxide particles that have a coating layer comprising carbon and alkali metal (and / or silicate) and / or alkaline earth metal (and / or silicate). In some embodiments, the composite powder particles can have a core-shell structure, wherein the disproportionated silicon oxide particles can form the core and the shell is a layer / coating that includes carbon and alkali metal (and / or silicate) and / or alkaline earth metal (and / or silicate). In some embodiments, there may be multiple coatings on the disproportionated silicon oxide particles. For example, the disproportionated silicon oxide particles may have a carbon coating and / or a coating of alkali metal (and / or silicate) and / or alkaline earth metal (and / or silicate), either on top of or under the carbon coating.

[0062] In some embodiments, the carbon content of the composite particle powder is about 0.1-20 wt.%, about 0.5-10 wt.%, or about 0.5-8 wt.%. In some embodiments, the carbon content of the composite particle powder is at least about 0.1 wt.% or at least about 0.5 wt.%. In some embodiments, the carbon content of the composite particle powder is at most about 20 wt.%, at most about 15 wt.%, at most about 10 wt.%, at most about 7.5 wt.%, at most about 5 wt.%, at most about 2.5 wt.%, or at most about 1 wt.%.Attorney Docket No.: L3-8121 WO

[0063] In some embodiments, the carbon in the coating of the composite particle powder is non-crystalline. In some embodiments, the alkali metal and / or alkaline earth metal content of the composite particle powder can the same as the alkali metal and / or alkaline earth metal content of the starting alkali metal salt and / or an alkaline earth metal.

[0064] In some embodiments, the amount of alkali metal and / or alkaline earth metal in the composite powder is about 0.01-15 wt.%, about 0.05-10 wt.%, or about 0.1-8 wt.%. In some embodiments, the amount of alkali metal and / or alkaline earth metal in the composite powder is at least about 0.01 wt.%, at least about 0.05 wt.%, at least about 0.1 wt.%, at least about 0.15 wt.%, at least about 0.5 wt.%, at least about 1 wt.%, at least about 2.5 wt.%, at least about 3 wt.%, at least about 4 wt.%, or at least about 4.5 wt.%. In some embodiments, the amount of alkali metal and / or alkaline earth metal in the composite powder is at most about 15 wt.%, at most about 10 wt.%, at most about 8 wt.%, at most about 6 wt.%, at most about 5 wt.%, at most about 4.5 wt.%, at most about 3 wt.%, at most about 2.5 wt.%, at most about 1 wt.%, or at most about 0.5 wt.%.

[0065] In some embodiments, the alkali metal and / or alkaline earth metal content can be measured using Inductively Coupled Plasma (ICP) Spectroscopy.

[0066] In some embodiments, the alkali metal:SiO molar ratio and / or alkaline earth metal:SiO molar ratio is about 0.001-10, about 0.005-0.5, or about 0.0095-0.342. In some embodiments, the alkali metal:SiO molar ratio and / or alkaline earth metal:SiO molar ratio is at least about 0.001, at least about 0.005 at least about 0.0075, at least about 0.009, at least about 0.0095, at least about 0.01, at least about 0.1, at least about 0.2, or at least about 0.3. In some embodiments, the alkali metal:SiO molar ratio and / or alkaline earth metal:SiO molar ratio is at most about 10, at most about 1, at most about 0.75, at most about 0.5, at most about 0.4, at most about 0.35, at most about 0.1, at most about 0.05, or at most about 0.01.

[0067] In some embodiments, the composite particle powder can be used as an electrode (e.g., anode) active material. In some embodiments, the composite powder (together with other anode additives and / or other anode active material(s)) can be coated onto a current collector (in the form of a slurry that includes the composite powder). In some embodiments, at least a portion of this coated current collector can become at least part of an electrode (e.g., an anode). In some embodiments, an electrode (e.g., an anode) with the composite powder as the active material can be used in a battery (e.g., a lithium-ion battery). In some embodiments, the battery can include an anode, a cathode, a separator, and / or an electrolyte. In some embodiments, the battery can be a solid-state battery.Attorney Docket No.: L3-8121 WO

[0068] For the purpose of clarity and a concise description, features are described herein as part of the same or separate embodiments; however, it will be appreciated that the scope of the disclosure includes embodiments having combinations of all or some of the features described. EXAMPLES

[0069] The following examples are presented for purposes of illustration, and are not intended to impose limitations on the scope of this disclosure.

[0070] To test the necessity of the lithium silicates, a reaction was conducted under the same conditions except replacing LiOH with NaOH yielding a product with similarly high Coulombic efficiency and capacity when installed into an electrode for Lithium ion storage (Table 1).

[0071] Examples 1-3 were made according to the following process: 1. Dissolve 0.385 mol alkali salt in 200 g of a solution of 14% PAA in water (wt / wt); 2. weigh 6.68 g AOH / PAA / H2O solution and 2g PAA / H2O solution into plastic vessel with screw cap lid; 3. add 12.5 g C coated SiO (Sangfroid) to vessel; 4. mix using high frequency acoustic mixer for 3 minutes, resulting in a thick, grey / black slurry; 5. Place slurry in silica boat (MTI); 6. Place boat in horizontal tube furnace (MTI) and affix gas manifold to flow Ar gas (1 l / m) over the sample during calcination; 7. Heat the sample to 950 °C at a rate of 15°C / min. Calcine sample for 90 minutes at 950 °C. Allow sample to cool to room temperature under flowing argon in the furnace; and 8. Collect the resultant product as a brittle, grey / black solid. Grind to a powder in an agate mortar and pestle.

[0072] Lithiation, delithiation, and 1CE values were determined using electrodes composed solely of the active material cycled against a Li metal counterelectrode. The materials were cycled between 5 mV and 2.5 V at a rate of C / 20, based off a theoretical capacity of 1600 mAh / g. TABLE 1 Example Alkali Lithiation Delithiation 1CE Amorphous Disproportionation Si hydroxide (mAh / g) @ 1.5 V @1.5 content (%) (%) crystallite (mAh / g) V size (nm) 1 LiOH 1192 1067 89.5 16.5 80.9 35 2 NaOH 1360 1164 85.6 46.9 77 35 3 Na2CO3 997 773 77.5 56 67.5 110 Standard N / A 2270 1747 77 100 0 <5 SiOAttorney Docket No.: L3-8121 WO

[0073] The lithiation and delithiation capacities of disproportionated SiO generated by reaction with LiOH or NaOH are shown in the above Table 1. A comparison to non- disproportionated SiO is provide as well. After reaction with both LiOH or NaOH, the lithiation capacities decrease but the first cycle Coulombic efficiency drastically increases. In comparing the relevant structural parameters, reacting with either alkali hydroxide yielded a decrease in amorphous content along with a large magnitude of disproportionation. The x-ray diffractions of Examples 1-3 can be shown in FIGS.2A-2C, respectively.

[0074] Example Calculation of Disproportionation Percentage

[0075] 1. Combine 800 mg of the reacted product (composite powder such as that in step 8 above) with 200 mg of corundum Al2O3 (Sigma Aldrich). Grind to homogeneity in an agate mortar and pestle.

[0076] 2. Collect X-ray diffraction pattern with a minimum range of 10-60 ° 2θ using a Cu X-ray source (λ = 1.54 angstrom), a maximum step size of 0.02 degrees and a minimum counting time of 0.5 sec / step / detector channel.

[0077] 3. Refine the data using the Rietveld method using Bruker D8 Advance and fit using TOPAS, using the added Al2O3 as an internal standard to determine amorphous content. Constraining the weight percent of Al2O3 to 20% allows determination of missing intensity which is then attributed to amorphous material in the product. Other phases that are commonly found include elemental silicon, quartz SiO2, cristobalite SiO2, and Li2SiO3 and Li2Si2O5 if lithium alkali metal is used. The sum of all crystalline phases and amorphous content is 100%.

[0078] 4. Determine the degree of disproportionation by comparing the refined wt% of Si (step 3) with the theoretical maximum wt% of Si in the SiO precursor: SiO → ½ Si + ½ SiO2, 28.0855 g / mol / (28.0855 + 28.0855 + 15.999 + 15.999)g / mol = 0.318 = maximum Si0. If refined Si = 25 wt%, then disproportionation = 0.25 / 0.318 = 0.79 or 79%

[0079] Example Calculation of Amorphous Content

[0080] The following is if LiOH was used as the alkali metal. The prelithiation reaction would be:^^ ^^^^^^^^ ^ ^^^^^^ → ^^^^௫^^^^^^^ା௫ / ଶ ^ 0.5^^ଶ^^

[0081] And would yield about 13g from 12.5 g SiO input.

[0082] 1. Combine 800 mg of the reacted product (^^^^௫^^^^^^^ା௫ / ଶ) with 200 mg of corundum Al2O3 (Sigma Aldrich). Grind to homogeneity in an agate mortar and pestle.Attorney Docket No.: L3-8121 WO

[0083] 2. Collect X-ray diffraction pattern with a minimum range of 10-60 ° 2θ using a Cu X-ray source (λ = 1.54 angstrom), a maximum step size of 0.02 degrees and a minimum counting time of 0.5 sec / step / detector channel.

[0084] 3. Refine the data using the Rietveld method using Bruker D8 Advance and fit using TOPAS, using the added Al2O3 as a 20% internal standard to determine amorphous content. Constraining the weight percent of Al2O3 to 20% allows determination of missing intensity which is then attributed to amorphous material in the product. Other phases that are commonly required include elemental silicon, quartz SiO2, cristobalite SiO2, Li2SiO3 and Li2Si2O5 if lithium alkali metal is used. The sum of all crystalline phases and amorphous content is 100%.

[0085] The calculation for an example can be shown in FIG. 2 that includes, where the overall amorphous content of the reacted product (composite powder) is 68.45%. DEFINITIONS

[0086] Unless defined otherwise, all terms of art, notations and other technical and scientific terms or terminology used herein are intended to have the same meaning as is commonly understood by one of ordinary skill in the art to which the claimed subject matter pertains. In some cases, terms with commonly understood meanings are defined herein for clarity and / or for ready reference, and the inclusion of such definitions herein should not necessarily be construed to represent a substantial difference over what is generally understood in the art.

[0087] The terms “powders” and “particles” used herein are equivalent, except that a single powder refers to a plurality of particles. This disclosure can apply to a wide range of particles and powders.

[0088] As used herein, the word “layer(s)” and “coating(s)” are equivalent. Specifically, each term “layer(s)” or “coating(s)” as used in relation to a particle(s) indicates that at least a portion of the surface of such particle, substantially all, or all of the surface of such particle(s) is covered by or in contact with the “layer(s)” or “coating(s).” Similarly, the term “coated” in relation to a particle(s) indicates that at least a portion of the surface of the particle, substantially all, or all of the surface of the particle(s) is covered by or in contact with the substance(s) with which the particle(s) is said to be “coated.”

[0089] Reference to “about” a value or parameter herein includes (and describes) variations that are directed to that value or parameter per se. For example, description referring to “about X” includes description of “X”. In addition, reference to phrases “less than”, “greater than”, “at most”, “at least”, “less than or equal to”, “greater than or equal to”, or other similarAttorney Docket No.: L3-8121 WO phrases followed by a string of values or parameters is meant to apply the phrase to each value or parameter in the string of values or parameters.

[0090] As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It is also to be understood that the term “and / or” as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items. It is further to be understood that the terms “includes, “including,” “comprises,” and / or “comprising,” when used herein, specify the presence of stated features, integers, steps, operations, elements, components, and / or units but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, units, and / or groups thereof.

[0091] This application discloses several numerical ranges in the text and figures. The numerical ranges disclosed inherently support any range or value within the disclosed numerical ranges, including the endpoints, even though a precise range limitation is not stated verbatim in the specification because this disclosure can be practiced throughout the disclosed numerical ranges.

[0092] The above description is presented to enable a person skilled in the art to make and use the disclosure, and is provided in the context of a particular application and its requirements. Various modifications to the preferred embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the disclosure. Thus, this disclosure is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.

Claims

Attorney Docket No.: L3-8121 WO CLAIMS 1. A method of producing a powder comprising: mixing an alkali metal salt and / or an alkaline earth metal salt, a liquid medium, and silicon monoxide particles to form a precursor suspension; heating the precursor particles to form a powder comprising disproportionated silicon monoxide particles having a coating comprising alkali metal and / or alkaline earth metal, wherein the disproportionation of the silicon monoxide is at least 30%.

2. The method of claim 1, wherein the alkali metal salt is a non-lithium alkali metal salt.

3. The method of claim 2, wherein the non-lithium alkali metal salt is sodium hydroxide or sodium carbonate.

4. The method of any one of claims 1-3, further comprising mixing a carbon precursor with the alkali metal salt and / or an alkaline earth metal salt, the liquid medium, and the silicon monoxide particles to form the precursor suspension.

5. The method of claim 4, wherein the carbon precursor comprises pentane, hexane, 2-methylhexane, cyclopentane, cyclohexane, methylcyclohexane, heptane, 4- methylheptane, octane, cyclooctane, nonane, decane, benzene, toluene, xylene, ethylbenzene, amylbenzene, methylethylbenzene, diethylbenzene, mesitylene, 1,2,4-triethylbenzene, 1,3,5-triethylbenzene, amylbenzene, tetrahydronaphthalene, refinery heavy oil, pitch, polyethylene, polypropylene, polyacrylic acid, polymaleic acid, polyfumaric acid, polycrotonic acid, poly(pentenoic) acid, polymethacrylic acid, polydimethacrylic acid, poly(allyl alcohol), poly(n-propyl)acrylate, poly(hydroxymethyl)acrylate, poly(2-hydroxyethyl)acrylate, poly(2- carboxyethyl)acrylate, poly(3-ethoxy-3-oxopropyl)acrylate, poly(methylcarbamylethyl)acrylate, poly(2-hydroxyethyl)methacrylate, polyvinylpyrrolidone, polyacrylamide, polymethacrylamide, poly(N- isopropyl)acrylamide, polyvinylacetamide, polyvinyl alcohol, polyvinyl-N- methylacetamide, poly(N-hydroxymethyl)acrylamide, poly(N- hydroxyethyl)acrylamide, poly(N-methoxymethyl)acrylamide, poly(N-Attorney Docket No.: L3-8121 WO ethoxymethyl)acrylamide, polyacrylonitrile, sucrose, natural polymers such as cellulose and polysaccharides, or combinations thereof.

6. The method of any one of claims 1-5, wherein the liquid medium comprises water, alcohols, esters, ketones, nitriles, halogenated hydrocarbons, or combinations thereof.

7. The method of any one of claims 1-6, wherein the silicon monoxide particles comprise carbon coated silicon monoxide particles.

8. The method of any one of claims 1-7, wherein the precursor suspension is heated to 700-1000oC.

9. The method of claim 8, wherein the precursor particles are heated in an inert gas.

10. The method of any one of claims 1-9, wherein the powder has an amorphous content of less than 60%.

11. The method of any one of claims 1-10, wherein the powder has a silicon crystallite size of less than 125 nm.

12. A powder comprising: disproportionated silicon monoxide particles having a coating comprising carbon and an alkali metal and / or alkaline earth metal, wherein the powder has an amorphous content of less than 60%.

13. The powder of claim 12, wherein the powder has a silicon crystallite size of less than 125 nm.

14. The powder of any one of claims 12-13, wherein the alkali metal is a non-lithium alkali metal.

15. The powder of claim 14, wherein the non-lithium alkali metal is sodium.

16. An anode comprising the powder of any one of claims 12-15.

17. A battery comprising the anode of claim 16.

18. The battery of claim 17, wherein the battery is a lithium-ion battery.

Images