Graphitized carbon materials for lithium-ion batteries from mesophase pitch prepared from aromatic feedstocks

Abstract

A method may include: heating an isotropic pitch composition in an inert atmosphere to form a mesophase pitch composition, wherein the isotropic pitch composition comprises: at least two monomers linked with at least one methylene bridge between each one of the at least two monomers, wherein each one of the at least monomers comprises one or more aromatic classes comprising one or more 5-membered rings, 6-membered rings, and any combination thereof; and wherein the isotropic pitch composition has a weight average molecular weight (Mw) of about 200 g / mol to about 1,500 g / mol, a softening point (Tsp) of 50 °C or greater, and a micro carbon residue (MCR) of about 5 wt.% or greater, based on a total weight of the isotropic pitch composition.

Description

[4600-22401]GRAPHITIZED CARBON MATERIALS FOR LITHIUM-ION BATTERIES FROM AROMATIC FEEDSTOCKSFIELD

[0001] The present disclosure relates to acid-mediated production of isotropic pitch compositions from aromatic hydrocarbon feedstocks and methods of using the isotropic pitch to produce graphite.BACKGROUND

[0002] Graphite is a carbon allotrope consisting of a great number of stacked sheets of sp2- hybridized carbons arranged in a highly ordered structure. Among the many beneficial attributes of graphite are its high thermal and electrical conductivity values, the latter of which may make graphite especially useful as an electrode material in batteries, for instance. In addition, the crystalline structure of graphite promotes an ability to store lithium ions through intercalation, which is useful for lithium-ion battery' applications. Additional applications in which graphite finds extensive use include, for example, fiber production, composite manufacturing, lubrication, and as electrodes for electric arc furnaces.

[0003] Graphite may be obtained from natural sources or produced synthetically through pyrolysis of a carbonaceous precursor. Suitable carbonaceous precursors for producing synthetic graphite include cokes and petroleum pitches, each of which contain large aromatic molecules that may be converted to graphite under pyrolysis conditions. For example, the large aromatic molecules in coke and petroleum pitches may first be converted to amorphous carbon in a carbonization process taking place at a temperature of about 700°C to about 1800°C, followed by subsequent conversion of the amorphous carbon to graphite in a graphitization process taking place at a higher temperature of about 2000°C to about 3400°C. Both conversion processes take place in the absence or substantial absence of oxygen. To achieve a high- percentage conversion of previously formed amorphous carbon to graphite (e.g., greater than 90% conversion of amorphous carbon to graphite on a mass basis), temperatures up to and exceeding 3000°C and extended reaction times up to about 20 hours may be utilized.

[0004] Petroleum byproducts with abundant aromatic fractions have been commonly used to produce mesophase pitch. However, oftentimes, such production process requires toxic and aggressive conditions such as the use of super-acids (e g., HF / BF3) or Lewis acids (e.g., AlCh). Moreover, the harsh acidic conditions and difficulties producing highly pure pitch materials limit the wide application of the current processes. Further, the physical and electronic[4600-22401] properties of the graphite and uniformity of the properties of the graphite depend on the orientation and uniformity' of the pitch and the purity of the pitch itself.SUMMARY

[0005] The present disclosure relates to acid-mediated production of isotropic pitch compositions from aromatic hydrocarbon feedstocks and methods of using the isotropic pitch to produce graphite.

[0006] In embodiments, a method may include: heating an isotropic pitch composition in an inert atmosphere to form a mesophase pitch composition, wherein the isotropic pitch composition comprises: at least two monomers linked with at least one methylene bridge between each one of the at least two monomers, wherein each one of the at least two monomers comprises one or more aromatic groups comprising at least one 5-membered ring, 6-membered ring, or any combination thereof; and wherein the isotropic pitch composition has a weight average molecular weight (Mw) of about 200 g / mol to about 1,500 g / mol, a softening point (Tsp) of 50 °C or greater, and a micro carbon residue (MCR) of about 5 wt.% or greater, based on a total w eight of the isotropic pitch composition.

[0007] In further embodiments, a method may include: mixing an aromatic feedstock comprising one or more aromatic compounds with at least one of formaldehyde, paraformaldehyde, or trioxane, in the presence of acetic acid to produce a first mixture; mixing a second mixture comprising sulfuric acid and acetic acid with to the first mixture at a temperature of about 40 °C to about 300 °C to form a third mixture comprising an isotropic pitch composition, wherein the isotropic pitch composition comprises: at least two monomers linked with at least one methylene bridge between each one of the at least two monomers, wherein each one of the at least two monomers comprise one or more aromatic groups; wherein the isotropic pitch composition has a weight average molecular weight (Mw) of about 200 g / mol to about 1,500 g / mol, a softening point (Tsp) of 50 °C or greater, and a micro carbon residue (MCR) of about 5 wt.% or greater, based on a total weight of the isotropic pitch composition; and heating the isotropic pitch composition in an inert atmosphere to form a mesophase pitch composition.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The following figures are included to illustrate certain aspects of the disclosure, and should not be viewed as exclusive configurations. The subject matter disclosed is capable of considerable modifications, alterations, combinations, and equivalents in form and function, as will occur to those skilled in the art and having the benefit of this disclosure.[4600-22401]

[0009] FIG. 1 is representative synthesis for forming an isotropic pitch composition produced from an aromatic feedstock comprising toluene according to embodiments of the present disclosure.

[0010] FIG. 2 is a representative synthesis for forming an isotropic pitch composition produced from an aromatic feedstock comprising para-xylene according to embodiments of the present disclosure.

[0011] FIG. 3 is flow diagram of synthesis of graphite according to embodiments of the present disclosure.

[0012] FIG. 4 is an optical micrograph mesophase pitch produced via thermal treatment of the synthetic pitch graphite according to embodiments of the present disclosure.

[0013] FIG. 5 is a graph of results of thermogravimetric analysis of synthetic pitch according to embodiments of the present disclosure.

[0014] FIG. 6 is an x-ray diffractogram of a carbonized mesophase pitch according to embodiments of the present disclosure.DETAILED DESCRIPTION

[0015] The present disclosure relates to acid-mediated production of isotropic pitch compositions from aromatic hydrocarbon feedstocks and methods of using the isotropic pitch to produce graphite. In embodiments, the graphite is included in high value carbon products such as graphite anodes for high-energ ' density' storage systems. In embodiments, a method of producing the graphite includes reacting an aromatic hydrocarbon feedstock with a methylene source in the presence of an acid to produce isotropic pitch. The isotropic pitch may then be converted to mesophase pitch by thermal treatment which is then further thermally treated to form the graphite. In some embodiments, the mesophase pitch is stabilized, such as by oxidation, prior to thermal treatment to form the graphite.

[0016] Embodiments of the present disclosure include isotropic pitch compositions comprising: at least two monomers linked with at least one methylene bridge between each one of the at least two monomers, wherein each one of the at least monomers comprises one or more aromatic groups comprising one or more 5-membered rings, 6-membered rings, or any combination thereof, and wherein the isotropic pitch composition has a weight average molecular weight (Mw) of about 300 g / mol to about 1,500 g / mol, a softening point (Tsp) of 40 °C or greater, or 500 °C or lower and a micro carbon residue (MCR) of about 5 wt.% or greater, based on the total weight of the isotropic pitch composition. The isotropic pitch compositions of the present disclosure are methylene-bridged aromatic oligomers produced by reacting aromatic feedstocks with formaldehyde or paraformaldehyde or trioxane in the[4600-22401] presence of acetic acid and sulfuric acid. Herein, the aromatic groups may comprise: unsubstituted aromatics and / or substituted aromatics selected from the group consisting of 1- ring aromatics (ARC1), 2-ring aromatics (ARC2), 3-ring aromatics (ARC3), 4 or more-ring aromatics (ARC4), 5-ring aromatics (ARC5), 6-ring aromatics (ARC6), 7-ring aromatics (ARC7), 8-ring aromatics (ARC8), 9-ring aromatics (ARC9), 10 or more-ring aromatics (ARC10+), or any combination thereof. The substituted aromatics may be selected from the group consisting of Ci to C20 hydrocarbyl monosubstituted aromatics, Ci to C20 hydrocarbyl disubstituted aromatics, Ci to C20 hydrocarbyl trisubstituted aromatics, and or combination thereof, such as the substituted aromatics selected from the group consisting of Ci to C10 hydrocarbyl monosubstituted aromatics, Ci to C10 hydrocarbyl disubstituted aromatics, Ci to C10 hydrocarbyl trisubstituted aromatics, or any combination thereof, such as the substituted aromatics can be selected from the group consisting of Ci to Cs hydrocarbyl monosubstituted aromatics, Ci to Cs hydrocarbyl disubstituted aromatics. Ci to Cs hydrocarbyl trisubstituted aromatics, or any combination thereof.

[0017] The isotropic pitch compositions may be produced from substituted and / or nonsubstituted single-ring aromatic feedstocks, substituted and / or non-substituted polycyclic aromatic hydrocarbon (PAH) feedstocks, or any combination thereof. Polycyclic aromatic hydrocarbon (PAH) may include two-ring aromatic feedstocks or multi-ring aromatic feedstocks (e.g., three ring aromatic feedstocks or greater). Scheme 1 illustrates an example synthesis of isotropic pitch mixed xylenes using paraformaldehyde as a methylene source and sulfuric acid as a catalyst and acetic acid as a solvent.Scheme 1

[0018] In embodiments, the methods for making the isotropic pitch compositions comprise: mixing an aromatic feedstock comprising one or more aromatic groups with paraformaldehyde in presence of acetic acid at ambient temperature to produce a first mixture; heating the first mixture at a temperature of about 40 °C to about 300 °C; and mixing a second mixture comprising sulfuric acid and acetic acid to the first mixture at a temperature of about 40 °C to about 300 °C to form a mix comprising an isotropic pitch composition, wherein the isotropic pitch composition comprises: at least two monomers linked with at least one methylene bridge between each one of the at least two monomers, wherein each one of the at least two monomers[4600-22401] comprises one or more aromatic groups comprising one or more 5-membered rings, 6- membered rings, or any combination thereof, and wherein the isotropic pitch composition has an average molecular weight (Mw) of about 300 g / mol to about 1,500 g / mol, a softening point (Tsp) of 50 °C or greater, and a micro carbon residue (MCR) of about 5 wt. % or greater, based on the total weight of the isotropic pitch composition.

[0019] Further, the isotropic pitch composition may have an average molecular weight (Mw) of about 200 g / mol to about 1500 g / mol. The isotropic pitch composition may comprise dimers, trimers, tetramers, pentamers, or any combination thereof. In some embodiments, the isotropic pitch composition may comprise trimers and tetramers, for example.

[0020] The reaction conditions of the methods herein affect the molecular weight distribution and the softening point of the isotropic pitch compositions. In some embodiments, the methods described herein enable the control of both the molecular weight distribution and the softening point of the isotropic pitch compositions by tuning the molar ratio of sulfuric acid and paraformaldehyde. The softening points of the isotropic pitch compositions may increase particularly with reaction time, the amount of sulfuric acid, and the amount of methylene source including formaldehyde and / or paraformaldehyde and / or trioxane. Further, little to no water is present in the reaction mixture, and any residual acids may be readily removed by filtration after washing the residue comprising the isotropic pitch composition with basic solution such as an aqueous solution of a Group I or Group II hydroxide or ammonium hydroxide; thus facilitating the isolation of the isotropic pitch composition as a highly pure material.

[0021] In embodiments, the methods described herein use a non-dehydrogenative synthetic route which provides a facile pathway to produce pitch precursors for the manufacturing of advanced carbon products. Further, the methods advantageously provide a way of producing high-quality synthetic isotropic pitch compositions, particularly with the ability to tune structural and other physical properties needed for addressing application-specific needs. The isotropic pitch compositions may be used as precursors of mesophase pitches for graphite anode for high-energy density storage systems, for example.Definitions and Test Methods

[0022] For the purposes of the present disclosure, the new numbering scheme for groups of the Periodic Table is used. In said numbering scheme, the groups (columns) are numbered sequentially from left to right from 1 through 18. The new numbering scheme for the Periodic Table Groups is used as described in Chemical and Engineering News, v. 63(5), pg. 27 (1985). Therefore, a "group 14" is an element from group 14 of the Periodic Table, e.g., C, Si, or Ge.[4600-22401]

[0023] For the purposes of the present disclosure and the claims thereto, the following definitions shall be used.

[0024] "Conversion" is the percentage of monomers that is converted to polymer product in a polymerization, and is reported as % and is calculated based on the polymer yield, the polymer composition, and the amount of monomers fed into the reactor.

[0025] Unless otherw ise specified, the term "Cn" means hydrocarbon(s) having n carbon atom(s) per molecule, wherein n is a positive integer.

[0026] The term “Cn” group or compound refers to a group or a compound comprising carbon atoms at total number thereof of n. Thus, a "Cm-Cn" group or compound refers to a group or compound comprising carbon atoms at a total number thereof in the range from m to n. Thus, a C1-C50 alkyl group refers to an alkyl group comprising carbon atoms at a total number thereof in the range from 1 to 50.

[0027] The terms "group," "radical," and "substituent" may be used interchangeably.

[0028] The terms "hydrocarbyl radical," "hydrocarbyl group," or "hydrocarbyl" may be used interchangeably and are defined to mean a group consisting of hydrogen and carbon atoms only. Preferred hydrocarbyls are Ci-Cioo radicals that may be linear, branched, or cyclic, and when cyclic, aromatic or non-aromatic. Examples of such radicals include, but are not limited to, alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tertbutyl, pentyd, iso-amyl, hexyl, octyl cyclopropyl, cyclobuty l, cyclopentyl, cyclohexyl, cyclooctyl, and the like, aryl groups, such as phenyl, benzy l naphthaleny 1, and the like.

[0029] Examples of saturated hydrocarby l groups include, but are not limited to. methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, iso-amyl (isopenty l), neopentyl, hexyl, octyl cyclopropyl, cyclobuty l, cyclopentyd, cyclohexyl, cyclooctyl, and the like, including their substituted analogues. Examples of unsaturated hydrocarbyl groups include, but are not limited to, ethenyl, propeny l, allyl, 1.4-butadienyl, cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, cyclooctenyl and the like, including their substituted analogues.

[0030] Examples of aromatic hydrocarby l groups include, but are not limited to, pheny l, tolyl, xylyl, naphthy l, and the like. Heteroary l and polynuclear heteroaryl groups may include, but are not limited to, pyridyl, quinohnyl, isoquinolinyl, pyrimidinyl, quinazolinyl, acridinyl, pyrazinyl, quinoxalinyl, imidazolyl, benzimidazolyl, pyrazolyl, benzopyrazoly 1, oxazolyl, benzoxazolyl, isoxazolyl, benzisoxazolyl, imidazoliny 1, thiophenyl, benzothiophenyl, furanyl and benzofuranyl. Polynuclear aryl groups may include, but are not limited to, naphthalenyl, anthracenyl, indanyl, indenyl, and tetralinyl.[4600-22401]

[0031] The “microcarbon residue test”, also referred to as “MCRT”, is a standard test method for the determination of carbon residue (micro method). The carbon residue value of the various petroleum materials serves as an approximation of the tendency of the material to form carbonaceous type deposits under degradation conditions similar to those used in the test method, and can be useful as a guide in manufacture of certain stocks. However, care needs to be exercised in interpreting the results. This test method covers the determination of the amount of carbon residue formed after evaporation and pyrolysis of petroleum materials under certain conditions and is intended to provide some indication of the relative coke forming tendency of such materials. Herein, the MCRT is measured according to the ASTM D4530-15 standard test method, using METTLER TOLEDO DP70 dropping point instrument, such as METTLER TOLEDO DP70.

[0032] As used herein, a “glass transition temperature” (Tg) refers to a mid-point of the temperature at which a continuous step change in heat capacity (or peak at the first derivative of heat flow) is recorded on the second heating scan of a differential scanning calorimeter (DSC) experiment at 10 °C / min heating and cooling rate. For purposes of the disclosure herein, Tg may be measured using thermal analysis TA INSTRUMENTS Q2000™, as indicated. DSC data analysis was performed using TA Instruments TRIOS software using the second heating curve.

[0033] The “softening point” refers to a temperature or a range of temperatures at which a substance softens. Herein, the softening point (SP) is measured using a METTLER TOLEDO dropping point instrument, such as METTLER TOLEDO DP70, according to a procedure analogous to ASTM D3104. Unless otherwise indicated, 'H and13C Nuclear Magnetic Resonance (NMR) spectra of the pitch compositions can be obtained using either a 400 MHz BRUKER AVANCE™ III HD spectrometer. Chemical shifts were referenced to tetramethylsilane (TMS) as an internal standard at 0.00 ppm for 'H spectra taken in CDCh containing 0.03 % (v / v) TMS.

[0034] The following abbreviations may be used through the present disclosure and claims: MCRT is microcarbon residue test, equiv is molar equivalent, ppm is parts per million, Tg is glass transition temperature; Tsp is softening point temperature.Isotropic Pitch Compositions

[0035] The isotropic pitch composition may comprise: at least two monomers linked with at least one methylene bridge between each one of the at least two monomers, wherein each one of the at least two monomers comprises one or more aromatic groups, and wherein the isotropic pitch composition has an average molecular weight (Mw) of about 300 g / mol to about 1,500[4600-22401] g / mol, a softening point (Tsp) of 40 °C or greater, and a micro carbon residue (MCR) of about 5 wt % or greater, based on the total weight of the isotropic pitch composition.

[0036] The isotropic pitch composition comprises a distribution of products, including dimers, trimers, and higher oligomers. Further, the isotropic pitch composition may have an average molecular weight (Mw) of about 300 g / mol to about 750 g / mol, wherein the isotropic pitch composition may comprise dimers, trimers, tetramers, pentamers, or any combination thereof. In some cases, the isotropic pitch composition may comprise trimers and tetramers.

[0037] The isotropic pitch compositions may be produced from substituted and / or nonsubstituted single-ring aromatic feedstocks, substituted and / or non-substituted polycyclic aromatic hydrocarbon (PAH) feedstocks, or any combination thereof. Polycyclic aromatic hydrocarbon (PAH) may include two-ring aromatic feedstocks or multi-ring aromatic feedstocks (e.g., three ring aromatic feedstocks or greater). Polycyclic aromatic hydrocarbon (PAH) may be a mixture of the above hydrocarbons such as AROMATIC-200™ a high solvency Cl 1 aromatic fluid available from ExxonMobil.

[0038] The one or more aromatic groups may be unsubstituted aromatics and / or substituted aromatics selected from the group consisting of 1-ring aromatics (ARC1), 2-ring aromatics (ARC2), 3-ring aromatics (ARC3), 4 or more-ring aromatics (ARC4), 5-ring aromatics (ARC5), 6-ring aromatics (ARC6), 7-ring aromatics (ARC7), 8-ring aromatics (ARC8), 9-ring aromatics (ARC9), 10 or more-ring aromatics (ARC10+), or any combination thereof.

[0039] The substituted aromatics may be selected from the group consisting of Ci to C20 hydrocarbyl monosubstituted aromatics, Ci to C20 hydrocarbyl disubstituted aromatics, Ci to C20 hydrocarbyl trisubstituted aromatics, or any combination thereof, such as the substituted aromatics can be selected from the group consisting of Ci to C10 hydrocarbyl monosubstituted aromatics, Ci to C10 hydrocarbyl disubstituted aromatics, Ci to C10 hydrocarbyl trisubstituted aromatics, or any combination thereof, such as the substituted aromatics can be selected from the group consisting of Ci to C5 hydrocarbyl monosubstituted aromatics, Ci to Cs hydrocarbyl disubstituted aromatics, Ci to C5 hydrocarbyl trisubstituted aromatics, or any combination thereof.

[0040] Nonlimiting examples of aromatic feedstocks may comprise benzene, toluene, xylenes (e.g., ortho-, meta-, para-substituted xylene), mesitylene, durane, naphthalene, 1- methylnaphthalene, 2-methylnaphthalene, 3 -methylnaphthalene, 2,6-dimethylnaphthalene, 1- ethylnaphthalene, 2-ethylnaphthalene, 1,7-diisopropylnaphthalene, 2,3- diisopropylnaphthalene, 2,6-diisopropylnaphthalene, 2,7-diisopropylnaphthalene, 1- butylnaphthalene. 2-butylnaphthalene, 1-tert-butylnaphthalene, 2-tert-butylnaphthalene,[4600-22401] anthracene, 1 -methyl anthracene, 2-methylanthracene, 9-methylanthracene, 9,10- dimethylanthracene, 9,10-diphethylanthracene, phenanthrene, 1 -methylphenanthrene, 1- ethylphenanthrene, 2-methylphenanthrene. 1 -phenylphenanthrene, 2,7-diphenylphenanthrene, pyrene, 1 -propylpyrene, 4-propylpyrene, 1,2,3-trimethylpyrenebenzopyrene, picene, coronene, chrysene, tetracene, pentacene, triphenylene, corannulene, fluorine, benzo [j] fluoranthene, Benzo[c]fluorene, peiylene, bcnzo-perylenc. ovalene, AROMATIC-200™, acenaphthene, or any isomers thereof, or any combination thereof.

[0041] The aromatic hydrocarbons or heterocyclic aromatic compounds may comprise 1 to 3 rings and they may be substituted by alkyl groups containing 1 to 6 carbon atoms, phenyl groups, or aralkyl groups containing 7 to 9 carbon atoms. Here, an aromatic hydrocarbon is advantageously selected from xylene, naphthalene, methylnaphthalene, dimethyl naphthalene, biphenyl, anthracene, phenanthrene, pyrene and their derivatives substituted with alkyl groups containing 1 to 6 carbon atoms. Polycyclic aromatic hydrocarbons may be naphthalene, methylnaphthalene, and dimethyl naphthalene and mixtures of these polycyclic aromatic hydrocarbons such as aromatic oils.

[0042] In cases where a polycyclic aromatic compound is used as a reactant, the compound, for example, may be an aromatic hydrocarbon oil containing 90 wt. % or more of naphthalene, high-purity naphthalene, or an aromatic hydrocarbon oil mainly containing naphthalene. Available as such hydrocarbon oils are the naphthalene oil fraction, methylnaphthalene oil fraction and intermediate oil fraction derived from coal tar or the intermediate products and residual oils obtained by recovering the principal components of these fractions by distillation, extraction and the like. These naphthalene- or methylnaphthalene-containing oils often occur as mixtures of the principal components and polycyclic aromatic hydrocarbons whose boiling points are close to each other. An aromatic hydrocarbon to be used in the reaction may be a mixture unless a pure raw material is used.

[0043] A naphthal ene-containing aromatic hydrocarbon oil naturally contains aromatic hydrocarbons as main components and may additionally contain heterocyclic aromatic compounds having nitrogen (N), sulfur (S), oxygen (O), and the like in the ring, aromatic compounds having functional groups containing the aforementioned heteroatoms or inert aliphatic hydrocarbons. In embodiments, an aromatic hydrocarbon oil containing 90 wt. % or more of naphthalene may be refined naphthalene, or 95 % grade naphthalene. This material may contain benzothiophene, methyl naphthalene and the like in addition to naphthalene.

[0044] The one or more aromatic groups may comprise partially hydrogenated aromatic rings, such as tetralin (also referred to as '’ 1.2.3.4-tetrahydronaphthalene'’) or indene, for example.[4600-22401]The one or more aromatic groups may be substituted with one or more alky l groups having 1 to 10 carbons, such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, and isomers thereof. The alkyl group may be straight chain, branched, or cyclic. The alkyl group may be saturated or unsaturated. In some embodiments, the alkyl group may include at least one aromatic group.

[0045] In embodiments, a methylene source includes formaldehyde or a compound which is capable of generating formaldehyde in the reaction system and formaldehyde, formalin, paraformaldehyde and the like may be used. It may be advantageous to use paraformaldehyde.

[0046] Nonlimiting examples of acids may comprise sulfuric acid, hydrochloric acid, nitric acid, acetic acid, phosphoric acid, citric acid, carbonic acid, oxalic acid, aromatic sulfonic acid.

[0047] The isotropic pitch composition may comprise: 0.1 wt. % to 100 wt % 1-ring aromatics (ARC1), 0.1 wt. % to 100 wt. % 2-ring aromatics (ARC2), 0.1 wt. % to 100 wt. % -3-ring aromatics (ARC3), 0.1 wt. % to 100 wt. % 4-ring aromatics (ARC4), 0.1 wt. % to 100 wt. % 5-ring aromatics (ARC5), 0.1 wt. % to 100 wt. % 6-ring aromatics (ARC6), 0.1 wt. % to 100 wt. % 7-ring aromatics (ARC7), 0.1 wt. % to 100 wt. % 8-ring aromatics (ARC8), 0.1 wt. % to 100 wt. % 9-ring aromatics (ARC9), 0.1 wt. % to 100 wt. % 10-ring or more aromatics (ARC10+), based on the total weight of the isotropic pitch composition.

[0048] The isotropic pitch composition may comprise 0. 1 wt. % to 100 wt. % 1-ring aromatics (ARC1) (0.1 wt. % to 95 wt. %, or 0.5 wt. % to 90 wt. %, or 1 wt. % to 85 wt. %, or 5 wt. % to 80 wt. %. or 10 wt. % to 75 wt. %, or 15 wt. % to 70 wt. %, or 20 wt. % to 65 wt. %, or 25 wt. % to 60 wt. %, or 30 wt. % to 55 wt. %, or 35 wt. % to 50 wt. %, or 40 wt. % to 45 wt. %, or 0.1 wt. % to 50 wt. %, or 0.5 wt. % to 45 wt. %, or 1 wt. % to 40 wt. %, or 1.5 wt. % to 35 wt. %, or 2 wt. % to 30 wt. %, or 2.5 wt. % to 25 wt. %, or 3 wt. % to 20 wt. %), based on the total w eight of the isotropic pitch composition.

[0049] The isotropic pitch composition may comprise: 0.1 wt. % to 100 wt. % 2-ring aromatics (ARC2) (0.1 wt. % to 95 wt. %, or 0.5 wt. % to 90 wt. %, or 1 wt. % to 85 wt. %, or 5 wt. % to 80 wt. %, or 10 wt. % to 75 wt. %, or 15 wt. % to 70 wt. %, or 20 wt. % to 65 wt. %, or 25 wt. % to 60 wt. %, or 30 wt. % to 55 wt. %, or 35 wt. % to 50 wt. %, or 40 wt. % to 45 wt. %, or 0. 1 wt. % to 50 wt. %, or 0.5 wt. % to 45 wt. %, or 1 wt. % to 40 wt. %, or 1.5 wt. % to 35 wt. %, or 2 wt. % to 30 wt. %, or 2.5 wt. % to 25 wt. %, or 3 wt. % to 20 wt. %), based on the total weight of the isotropic pitch composition.

[0050] The isotropic pitch composition may comprise: 0.1 wt. % to 100 wt. % 3-ring aromatics (ARC3) (0. 1 wt. % to 95 wt. %, or 0.5 wt. % to 90 wt. %, or 1 wt. % to 85 wt. %, or 5 wt. % to 80 wt. %. or 10 wt. % to 75 wt. %, or 15 wt. % to 70 wt. %, or 20 wt. % to 65 wt. %, or 25[4600-22401] wt. % to 60 wt. %, or 30 wt. % to 55 wt. %, or 35 wt. % to 50 wt. %, or 40 wt. % to 45 wt. %, or 0. 1 wt. % to 50 wt. %, or 0.5 wt. % to 45 wt. %, or 1 wt. % to 40 wt. %, or 1.5 wt. % to 35 wt. %, or 2 wt. % to 30 wt. %, or 2.5 wt. % to 25 wt. %, or 3 wt. % to 20 wt. %), based on the total weight of the isotropic pitch composition.

[0051] The isotropic pitch composition may comprise: 0.1 wt. % to 100 wt. % 4-ring aromatics (ARC4) (0.1 wt. % to 95 wt. %, or 0.5 wt. % to 90 wt. %, or 1 wt. % to 85 wt. %, or 5 wt. % to 80 wt. %. or 10 wt. % to 75 wt. %, or 15 wt. % to 70 wt. %, or 20 wt. % to 65 wt. %, or 25 wt. % to 60 wt. %, or 30 wt. % to 55 wt. %, or 35 wt. % to 50 wt. %, or 40 wt. % to 45 wt. %, or 0.1 wt. % to 50 wt. %, or 0.5 wt. % to 45 wt. %, or 1 wt. % to 40 wt. %, or 1.5 wt. % to 35 wt. %, or 2 wt. % to 30 wt. %, or 2.5 wt. % to 25 wt. %, or 3 wt. % to 20 wt. %), based on the total w eight of the isotropic pitch composition.

[0052] The isotropic pitch composition may comprise: 0.1 wt. % to 100 wt. % 5-ring aromatics (ARC5) (0.1 wt. % to 95 wt. %, or 0.5 wt. % to 90 wt. %, or 1 wt. % to 85 wt. %, or 5 wt. % to 80 wt. %, or 10 wt. % to 75 wt. %, or 15 wt. % to 70 wt. %, or 20 wt. % to 65 wt. %, or 25 wt. % to 60 wt. %, or 30 wt. % to 55 wt. %, or 35 wt. % to 50 wt. %, or 40 wt. % to 45 wt. %, or 0. 1 wt. % to 50 wt. %, or 0.5 wt. % to 45 wt. %, or 1 wt. % to 40 wt. %, or 1.5 wt. % to 35 wt. %, or 2 wt. % to 30 wt. %, or 2.5 wt. % to 25 wt. %, or 3 wt. % to 20 wt. %), based on the total weight of the isotropic pitch composition.

[0053] The isotropic pitch composition may comprise: 0.1 wt. % to 100 wt. % 6-ring aromatics (ARC6) (0. 1 wt. % to 95 wt. %, or 0.5 wt. % to 90 wt. %, or 1 wt. % to 85 wt. %, or 5 wt. % to 80 wt. %. or 10 wt. % to 75 wt. %, or 15 wt. % to 70 wt. %, or 20 wt. % to 65 wt. %, or 25 wt. % to 60 wt. %, or 30 wt. % to 55 wt. %, or 35 wt. % to 50 wt. %, or 40 wt. % to 45 wt. %, or 0.1 wt. % to 50 wt. %, or 0.5 wt. % to 45 wt. %, or 1 wt. % to 40 wt. %, or 1.5 wt. % to 35 wt. %, or 2 wt. % to 30 wt. %, or 2.5 wt. % to 25 wt. %, or 3 wt. % to 20 wt. %), based on the total weight of the isotropic pitch composition.

[0054] The isotropic pitch composition may comprise: 0. 1 wt. % to 100 wt. % 7-ring aromatics (ARC7) (0.1 wt. % to 95 wt. %, or 0.5 wt. % to 90 wt. %, or 1 wt. % to 85 wt. %, or 5 wt. % to 80 wt. %, or 10 wt. % to 75 wt. %, or 15 wt. % to 70 wt. %, or 20 wt. % to 65 wt. %, or 25 wt. % to 60 wt. %, or 30 wt. % to 55 wt. %, or 35 wt. % to 50 wt. %, or 40 wt. % to 45 wt. %, or 0. 1 wt. % to 50 wt. %?or 0.5 wt. % to 45 wt. %, or 1 wt. % to 40 wt. %, or 1.5 wt. % to 35 wt. %, or 2 wt. % to 30 wt. %, or 2.5 wt. % to 25 wt. %, or 3 wt. % to 20 wt. %), based on the total w eight of the isotropic pitch composition.

[0055] The isotropic pitch composition may comprise: 0.1 wt. % to 100 wt. % 8-ring aromatics (ARC8) (0. 1 wt. % to 95 wt. %, or 0.5 wt. % to 90 wt. %. or 1 wt. % to 85 wt. %, or 5 wt. %[4600-22401] to 80 wt %, or 10 wt. % to 75 wt. %, or 15 wt. % to 70 wt. %, or 20 wt. % to 65 wt. %, or 25 wt. % to 60 wt. %, or 30 wt % to 55 wt. %, or 35 wt. % to 50 wt. %, or 40 wt. % to 45 wt. %, or 0. 1 wt. % to 50 wt. %, or 0.5 wt. % to 45 wt. %, or 1 wt. % to 40 wt. %, or 1.5 wt. % to 35 wt. %, or 2 wt. % to 30 wt. %, or 2.5 wt. % to 25 wt. %, or 3 wt. % to 20 wt. %), based on the total weight of the isotropic pitch composition.

[0056] The isotropic pitch composition may comprise: 0.1 wt. % to 100 wt. % 9-ring aromatics (ARC9) (0. 1 wt. % to 95 wt. %, or 0.5 wt. % to 90 wt. %, or 1 wt. % to 85 wt. %, or 5 wt. % to 80 wt. %, or 10 wt. % to 75 wt. %, or 15 wt. % to 70 wt. %, or 20 wt. % to 65 wt. %, or 25 wt. % to 60 wt. %, or 30 wt. % to 55 wt. %, or 35 wt. % to 50 wt. %, or 40 wt. % to 45 wt. %, or 0. 1 wt. % to 50 wt. %, or 0.5 wt. % to 45 wt. %, or 1 wt. % to 40 wt. %, or 1.5 wt. % to 35 wt. %, or 2 wt. % to 30 wt. %, or 2.5 wt. % to 25 wt. %, or 3 wt. % to 20 wt. %), based on the total weight of the isotropic pitch composition.

[0057] The isotropic pitch composition may comprise: 0. 1 wt. % to 100 wt. % 10-ring or more aromatics (ARC 10+) (0. 1 wt. % to 95 wt. %, or 0.5 wt. % to 90 wt. %, or 1 wt. % to 85 wt. %, or 5 wt. % to 80 wt. %, or 10 wt. % to 75 wt. %, or 15 wt. % to 70 wt. %, or 20 wt. % to 65 wt. %, or 25 wt. % to 60 wt. %, or 30 wt. % to 55 wt. %, or 35 wt. % to 50 wt. %, or 40 wt. % to 45 wt. %, or 0. 1 wt. % to 50 wt. %, or 0.5 wt. % to 45 wt. %, or 1 wt. % to 40 wt. %, or 1.5 wt. % to 35 wt. %, or 2 wt. % to 30 wt. %, or 2.5 wt. % to 25 wt. %, or 3 wt. % to 20 wt. %), based on the total w eight of the isotropic pitch composition.

[0058] The isotropic pitch composition may comprise: 0.1 wt. % to 100 wt. % ARC1, 0.1 wt. % to 100 wt. % ARC2, 0. 1 wt. % to 80 wt. % ARC3, 0. 1 wt. % to 50 wt. % ARC4. 0. 1 wt. % to 50 wt. % ARC5, 0. 1 wt. % to 25 wt. % ARC6, 0. 1 wt. % to 25 wt. % ARC7, 0 wt. % to 10 wt. % ARC8, 0 wt. % to 10 wt. % ARC9, 0 wt. % to 5 wt. % ARC10+, based on the total weight of the isotropic pitch composition.

[0059] Further, the isotropic pitch composition may have a softening point (Tsp) of about 500 °C or less (or from about 40 °C to about 500 °C, or from about 100 °C to about 490 °C, or from about 110 °C to about 480 °C, or from about 120 °C to about 470 °C, or from about 130 °C to about 460 °C, or from about 140 °C to about 450 °C, or from about 150 °C to about 440 °C, or from about 160 °C to about 430 °C, or from about 170 °C to about 420 °C, or from about 180 °C to about 410 °C, or from about 200 °C to about 400 °C or from about 200 °C to about 800 °C). In some cases, the isotropic pitch composition may have a Tspof about 400 °C or less, such as about 350 °C or less, such as about 300 °C or less, such as about 250 °C or less, such as about 200 °C or less.[4600-22401]

[0060] The isotropic pitch composition may have a glass transition temperature (Tg) ranging from about 100 °C to about 500 °C (or from about 60 °C to about 180 °C, or from about 70 °C to about 160 °C, or from about 80 °C to about 140 °C, or from about 90 °C to about 120 °C. or from about 40 °C to about 100 °C, or from about 100 °C to about 200 °C).

[0061] The isotropic pitch composition may have a micro carbon residue (MCR) of about 40 wt. % or less (or 35 wt. % or less, or 30 wt. % or less), based on the total weight of the isotropic pitch composition. The isotropic pitch composition may have a micro carbon residue (MCR) of from about 18 wt. % to about 40 wt. %, based on the total weight of the isotropic pitch composition. In embodiments, the isotropic pitch composition has an MCR at a point in a range of from about 5 wt.% to about 95 wt.%.

[0062] The isotropic pitch composition may have an average molecular weight (Mw) of about 200 g / mol to about 1,500 g / mol (or about 400 g / mol to about 1,200 g / mol, or about 500 g / mol to about 1 ,000 g / mol, or about 600 g / mol to about 800 g / mol, or about 300 g / mol to about 1 ,000 g / mol, or about 300 g / mol to about 500 g / mol). Alternately, the isotropic pitch composition may have an average molecular weight (Mw) of about 500 g / mol or less (or about 100 g / mol to about 500 g / mol. or about 150 g / mol to about 400 g / mol. or about 200 g / mol to about 350 g / mol, or about 250 g / mol to about 300 g / mol, or about 100 g / mol to about 250 g / mol, or about 250 g / mol to about 500 g / mol).

[0063] Methods for making the isotropic pitch compositions described above may comprise: mixing an aromatic feedstock comprising one or more aromatic groups with paraformaldehyde, in the presence of acetic acid at ambient temperature to produce a first mixture: heating the first mixture at a temperature of about 40 °C to about 300 °C; and mixing a second mixture comprising sulfuric acid and acetic acid to the first mixture at a temperature of about 40 °C to about 300 °C to form a mix comprising an isotropic pitch composition, wherein the isotropic pitch composition comprises: at least two monomers linked with at least one methylene bridge between each one of the at least two monomers, wherein each one of the at least monomers comprises one or more aromatic groups, and wherein the isotropic pitch composition has a weight average molecular weight (Mw) of about 200 g / mol to about 1,500 g / mol, a softening point (Tsp) of 40 °C or greater, and a micro carbon residue (MCR) of about 5 wt. % or greater, based on the total weight of the isotropic pitch composition. Without being bound by any theory, it is believed that the reaction may be initiated via Friedel-Craft acylation reaction, followed by condensation reactions.

[0064] Further, the isotropic pitch composition may have an average molecular weight (Mw) of about 300 g / mol to about 750 g / mol. wherein the isotropic pitch composition may comprise[4600-22401] dimers, trimers, tetramers, pentamers, or any combination thereof. In some embodiments, the isotropic pitch composition may comprise trimers and tetramers.

[0065] A nonlimiting example of an isotropic pitch composition may be produced from an aromatic feedstock comprising toluene. A representative synthesis is shown in FIG. 1 .

[0066] Another nonlimiting example of an isotropic pitch composition may be produced from an aromatic feedstock comprising para-xylene. A representative synthesis is shown in FIG. 2.

[0067] Mixing the aromatic feedstock and paraformaldehyde may be carried out at a molar ratio aromatic feedstock: formaldehyde (or paraformaldehyde) of from about 10: 1 to about 1: 10 (or about 1: 1 to about 1:10, or about 1 : 1.5 to about 1 :9, or about 1 :2 to about 1 :8, or about 1:2.5 to about 1:7, or about 1:3 to about 1 :6, or about 1 :4 to about 1:5). In at least one embodiment, the molar ratio aromatic feedstock: paraformaldehyde is 1 :3. Notwithstanding, the paraformaldehyde molar ratio is based on the formaldehyde molar equivalent.

[0068] Further, the addition of sulfuric acid may be carried out at a molar ratio aromatic feedstock: sulfuric acid of from about 1 :0.001 to about 1:20 (or about 1 :0.01 to about 1: 19, or about 1:0.1 to about 1: 18, or about 1 :0.5 to about 1: 17, or about 1:1 to about 1: 16, or about 1 : 1.5 to about 1: 15, or about 1:2 to about 1: 14, or about 1:2.5 to about 1 : 13. or about 1:3 to about 1 : 12, or about 1 :3.5 to about 1 : 1 1, or about 1:4 to about 1 : 10). In at least one embodiment, the molar ratio aromatic feedstock: sulfuric acid is 1:1.

[0069] The mixing of the second mixture comprising sulfuric acid and acetic acid to the first mixture comprising the aromatic feedstock and paraformaldehyde may be carried out at a temperature of about 40 °C to about 300 °C, such as about 50 °C to about 100 °C, such as about 60 °C to about 80 °C, such as about 40 °C to about 60 °C, such as about 60 °C to about 90 °C, for a time period of about 24 hours or less (or about 5 minutes to about 24 hours, or about 10 minutes to about 5 hours, or about 15 minutes to about 4 hours, or about 20 minutes to about 3 hours, or about 25 minutes to about 2 hours, or about 30 minutes to about 1 hour, for example), although the conditions may vary with the raw materials and acids in use.

[0070] Separating the isotropic pitch composition from any remaining paraformaldehyde, sulfuric acid and / or acetic acid may be performed by filtration of the reaction mixture, using alkalis to wash the residue and neutralize the acids. The paraformaldehyde, sulfuric acid and / or acetic acid recovered from the separation may be recycled to minimize its consumption in the process, for example.

[0071] Suitable examples of alkalis may be water-soluble alkalis such as sodium hydroxide, potassium hydroxide, ammonium hydroxide, and sodium carbonate. “Water-soluble” means that not only the alkalis themselves are water-soluble but also the salts to be formed by their[4600-22401] reaction with acids are water-soluble. Moreover, “alkali” means a substance which can neutralize an acid, and its examples are hydroxides and weak acid salts such as carbonates of alkali metals and alkaline earth metals. For example, sodium hydroxide may be used during the filtration process as it is readily available and soluble in many acids.

[0072] The methods of synthesizing the isotropic pitch may further comprise cooling the mixture comprising an isotropic pitch composition to ambient temperature; and separating the isotropic pitch composition from any remaining paraformaldehyde, sulfuric acid and / or acetic acid.

[0073] In some instances, mixing the second mixture comprising sulfuric acid and acetic acid to the first mixture may be carried out at atmospheric pressure.

[0074] In embodiments, the methods of synthesizing the isotropic pitch may be carried out without any use of solvent (i.e., neat mixing the aromatic feedstock, the sulfuric acid, and the formaldehyde, for instance). In some instance, solvents used for producing the isotropic pitch composition may be miscible with the aromatic feedstock, the formaldehyde, and / or the acids.

[0075] The isotropic pitch compositions may be used as a precursor for the production of mesophase pitches, and further for graphite anodes for high-energy density storage systems. Mesophase Pitch Compositions:

[0076] Methods for preparing a mesophase pitch composition from the isotropic pitch composition may include thermally treating the isotropic pitch composition at elevated temperature in inert atmosphere. In some embodiments, the isotropic pitch composition is heated in a nitrogen atmosphere. In embodiments, the isotropic pitch composition is heated at a temperature below the softening temperature such as a temperature above room temperature and below about 500°C, or below about 400°C, or below about 300°C, or below about 200°C, such as within a range of about 200°C to about 450°C, or about 200°C to about 300°C, or about 200°C to about 250°C, or about 250°C to about 350°C, or about 300°C to about 450°C, or any ranges therebetween. In embodiments, the isotropic pitch composition is heated for a period of time at a point in a range of 0.5 hour to 10 hours. Alternatively, the isotropic pitch composition is heated for a period of time at a point in a range of 0.5 hour to 3 hours, 3 hours to 6 hours, 6 hours to 10 hours, or any ranges therebetween.

[0077] Mesophase pitches disclosed herein include a mesophase content of 0.1 wt.% to 100 wt.%. The mesophase content of a pitch may be determined using ASTM D4616-95, for example.

[0078] In embodiments, the mesophase pitch has low contamination level of metals, sulfur, and particles, The mesophase pitch may have contamination level of all the metals from 0 ppm[4600-22401] to about 100 ppm, or from about 1 ppm to about 75 ppm, or from about 10 ppm to about 50 ppm, or from about 15 ppm to about 25 ppm, for example. The mesophase pitch may have contamination level of sulfur from 0 ppm to about 100 ppm. or from about 1 ppm to about 75 ppm, or from about 10 ppm to about 50 ppm, or from about 15 ppm to about 25 ppm, for example. The mesophase pitch may have contamination level of particles of less than 100 pm from 0 ppm to about 100 ppm, or from about 1 ppm to about 75 ppm, or from about 10 ppm to about 50 ppm, or from about 15 ppm to about 25 ppm, for example.

[0079] Further, the mesophase pitch composition may have a softening point (Tsp) of about 200 °C or greater such as at a point in a range of from about 200 °C to about 500 °C, or from about 500 °C to about 600 °C, from about 600 °C to about 700 °C, or from about 700 °C to about 800 °C, or any ranges therebetween.

[0080] The mesophase pitch composition may have a glass transition temperature (Tg) at a point in a range of from about 100 °C to about 500 °C, or from about 150 °C to about 250 °C, or from about 200 °C to about 300 °C, or from about 250 °C to about 350 °C, or from about 350 °C to about 400 °C, or from about 400 °C to about 450 °C, or from about 450 °C to about 500 °C, or any ranges therebetween.

[0081] The mesophase pitch composition may have a micro carbon residue (MCR) of about 95 wt. % or less (or 40 wt. % or less, or 30 wt. % or less), based on the total weight of the mesophase pitch composition. The mesophase pitch composition may have a micro carbon residue (MCR) of from about 18 wt. % to about 95 wt. %, based on the total w eight of the mesophase pitch composition.

[0082] The mesophase pitch composition may have an average molecular weight (Mw) at a point in a range of from about 300 g / mol to about 2,000 g / mol, or about 400 g / mol to about 1,500 g / mol, or about 500 g / mol to about 1,250 g / mol, or about 600 g / mol to about 1,000 g / mol, or about 300 g / mol to about 750 g / mol, or about 300 g / mol to about 500 g / mol. or any ranges therebetween.

[0083] In embodiments, the mesophase pitch is stabilized to form a stabilized mesophase pitch composition, such as by thermal in a low-oxygen environment (e.g., about 0.1 mol% oxygen to about 20 mol% oxygen) below the softening temperature of the mesophase pitch. At least some oxidation of the mesophase pitch may take place under such conditions to provide a number of benefits. Namely, when heating mesophase pitch in a low-oxygen environment below the softening temperature of the mesophase pitch, mechanical integrity of the composite powder and carbon matrices produced therefrom may be enhanced through at least partial crosslinking of the mesophase pitch. The at least partial crosslinking may increase the softening[4600-22401] temperature of the mesophase pitch as well, thereby allowing the pitch to maintain its shape more readily as the composite powder is heated up during carbonization or graphitization.

[0084] In non-limiting examples, the foregoing heating below the softening temperature may take place at a temperature below the softening temperature such as a temperature above room temperature and below about 500°C, or below about 400°C, or below about 300°C, or below about 200°C, such as within a range of about 200°C to about 450°C, or about 200°C to about 300°C, or about 200°C to about 250°C, or about 250°C to about 350°C, or about 300°C to about 450°C, or any ranges therebetween. The actual heating temperature may be selected based upon the initial softening temperature of the mesophase pitch. In embodiments, the mesophase pitch it heated at a temperature ramp at a point in a range from 1 °C per minute to 5 °C per minute under a flux of air The low-oxygen environment may have an oxygen concentration from ranging from about 0.1 mol% to about 20 mol%, or about 1 mol% to about 15 mol%, or about 1 mol% to about 10 mol%, or about 1 mol% to about 5 mol%, or less than about 5 mol%, or less than about 1 mol%. Thus, in some examples, the mesophase pitch may be heated at a temperature ranging from about 200°C to about 450°C, or about 200°C to about 300°C, or about 300°C to about 450°C, or about 250°C to about 400°C in an environment containing about 0.1 mol% to about 20 mol% oxygen. When heated under the foregoing conditions, at least some crosslinking of the mesophase pitch may take place. A concurrent increase in softening temperature may occur upon crosslinking of the mesophase pitch.Graphitic Composition:

[0085] The above mesophase pitch may serve as a precursor composite for forming carbon composites in which the mesophase pitch is pyrolyzed (carbonized) to form a carbon matrix comprising amorphous carbon and / or graphite. Amorphous carbon may be distinguished from graphite spectroscopically by powder X-ray diffraction, for example. Amorphous carbon or carbonized samples may be defined as ones with a degree of graphitization of up to 60%. Conversion of the mesophase pitch to a graphite-containing composite may occur with initial conversion of the mesophase pitch to amorphous carbon at a first heating temperature, followed by a subsequent heating operation at a second heating temperature that is higher than the first heating temperature to form graphite, each heating operation being conducted under conditions that may lead to a minimal reaction with oxygen. Amorphous carbon may be formed upon exposing the mesophase pitch to a temperature ranging from about 700°C to about 1800°C, or about 900°C to about 1800°C, preferably about 900°C to about 1500°C or about 1000°C to about 1500°C, or more preferably about 900°C to about 1400°C, in a no-oxygen or very low- oxygen environment (e.g, an oxygen content below about 0.1 mol% or below), preferably in[4600-22401] the presence of an inert gas environment. Thus, in some examples, the mesophase pitch may be at least partially carbonized to form a carbonaceous composition at a carbonization temperature ranging from about 700°C to about 1800°C or about 900°C to about 1500°C in an environment comprising about 0. 1 mol% oxygen or below, which may at least partially convert the mesophase pitch to amorphous carbon.

[0086] After converting the mesophase pitch to amorphous carbon, graphitization of the amorphous carbon may then occur. Under un-catalyzed conditions, graphite may be formed from amorphous carbon by heating to a higher temperature ranging from about 2000°C to about 3400°C, or about 2500°C to about 3400°C in a no-oxygen or very low-oxygen environment, preferably in the presence of an inert gas environment, over a time that may range up to about 24 hours, or up to about 48 hours, or even up to about 72 hours. In embodiments where the mesophase pitch includes a graphitization catalyst, increased graphite yields may be realized at lower heating temperatures and / or over a shorter heating time.

[0087] In non-limiting examples, graphitization of the amorphous carbon disclosed herein may take place at a graphitization temperature up to about 3400°C, such as a graphitization temperature ranging from about 2000°C to about 3400°C. or about 2000°C to about 2500°C, or about 2500°C to about 3000°C, or about 2800°C to about 3200°C, or about 2200°C to about 2800°C, or even at a graphitization temperature lower than about 2000°C but above the carbonization temperature. In embodiments, a heating ramp rate during carbonization / graphitization includes a temperature ramp ranging from 5 °C per minute to 10 °C per minute under nitrogen atmosphere. Under the foregoing conditions, the time period over which graphitization is conducted may be about 18 hours or less, or about 15 hours or less, or about 12 hours or less, or about 10 hours or less, or about 9 hours or less, or about 8 hours or less, or about 7 hours or less, or about 6 hours or less, or about 5 hours or less, or about 4 hours or less, or about 3 hours or less, or about 2 hours or less, or about 1 hour or less. In some examples, graphitization may take place at a graphitization temperature of about 3000°C to about 3400°C but over a short graphitization time of about 1 hour or less, or about 50 minutes or less, or about 40 minutes or less, or about 30 minutes or less, or about 20 minutes or less, or about 10 minutes or less. Thus, in at least some examples, after at least partially carbonizing the mesophase pitch, heating above a carbonization temperature may take place in a no-oxygen or very low-oxygen environment comprising 0.1 mol% oxygen or below to convert at least a portion of the amorphous carbon into a graphitic composition.

[0088] The compositions resulting from initial carbonization of the mesophase pitch to form amorphous carbon may be isolated and / or analyzed before subsequent conversion to graphite[4600-22401] takes place. Alternately, the compositions obtained following carbonization may be directly heated to a graphitization temperature without undergoing cooling following carbonization. That is, carbonization and graphitization of the composite powders may take place in a single heating operation in some instances.

[0089] Accordingly, such compositions may be produced by a process including heating the mesophase pitch to a carbonization temperature sufficient to form the carbon matrix in a nooxygen or very low-oxygen environment comprising about 0.1 mol% oxygen or below, wherein the graphitization catalyst precursor, if present, is converted to the graphitization catalyst while forming the carbon matrix. The petroleum pitch or amorphous carbon may be further converted to graphite at a suitable graphitization temperature, as discussed further herein. In either case, heating may take place in an environment comprising about 0. 1 mol% oxygen or below.

[0090] FIG. 3 is a schematic of workflow 300 of the synthesis of graphite suitable for graphite anode for high-energy storage system from aromatic feeds according to embodiments of the present disclosure. In block 302, an aromatic feed, such as those disclosed above, is mixed with acid and a methylene source such as paraformaldehyde. The mixture is allowed to react at conditions suitable for the formation of isotropic pitch. In block 304, the isotropic pitch produced in block 302 is thermally treated in inert atmosphere to transform at least a portion of the isotropic pitch to mesophase pitch. In block 306, the mesophase pitch produced in block 304 is stabilized, such as by oxidation, as described herein. In block 308. the stabilized pitch undergoes thermolysis at elevated temperatures to form the graphite.

[0091] Embodiments disclosed herein include:

[0092] Embodiment 1. A method comprising: heating an isotropic pitch composition in an inert atmosphere to form a mesophase pitch composition, wherein the isotropic pitch composition comprises: at least two monomers linked with at least one methylene bridge between each one of the at least two monomers, wherein each one of the at least two monomers comprises one or more aromatic groups comprising at least one 5-membered ring, 6-membered ring, or any combination thereof; and wherein the isotropic pitch composition has a weight average molecular weight (Mw) of about 200 g / mol to about 1,500 g / mol, a softening point (Tsp) of 50 °C or greater, and a micro carbon residue (MCR) of about 5 wt.% or greater, based on a total weight of the isotropic pitch composition.

[0093] Embodiment 2. The method of embodiment 1 wherein the mesophase pitch composition has a softening point at a point in a range of from about 200 °C to about 800 °C as measured according to ASTM D3104.[4600-22401]

[0094] Embodiment 3. The method of any of embodiments 1-2 wherein the mesophase pitch composition has a glass transition temperature (Tg) at a point in a range of from about 100 °C to about 500 °C.

[0095] Embodiment 4. The method of any of embodiments 1-3 wherein the mesophase pitch composition has a micro carbon residue (MCR) of from about 5 wt. % to about 95 wt. %, based on a total weight of the mesophase pitch composition.

[0096] Embodiment 5. The method of any of embodiments 1-4 further comprising stabilizing the mesophase pitch composition by heating the mesophase pitch composition at a temperature below the softening point of the mesophase pitch in an atmosphere comprising oxygen to form a stabilized mesophase pitch composition.

[0097] Embodiment 6. The method of any of embodiments 1-5 wherein the oxygen is present in an amount of about 0. 1 mol% to about 20 mol% in the atmosphere comprising oxygen.

[0098] Embodiment 7. The method of any of embodiments 1-6 further comprising heating the stabilized mesophase pitch composition at a carbonization temperature in an inert atmosphere to form a carbonaceous composition comprising amorphous carbon.

[0099] Embodiment 8. The method of any of embodiments 1-7 wherein the stabilized mesophase pitch composition is heated to a temperature at a point in a range of from about 700°C to about 1800°C.

[0100] Embodiment 9. The method of any of embodiments 1-8 further comprising heating the carbonaceous composition at a graphitization temperature in an inert atmosphere to form a graphitic composition.

[0101] Embodiment 10. The method of any of embodiments 1-9 wherein the carbonaceous composition is heated to a temperature at a point in a range of from about 2000°C to about 3400°C.

[0102] Embodiment 11. A battery anode comprising the graphitic composition of claim 9.

[0103] Embodiment 12. A method comprising: mixing an aromatic feedstock comprising one or more aromatic compounds with at least one of formaldehyde, paraformaldehyde, or trioxane, in the presence of acetic acid to produce a first mixture; mixing a second mixture comprising sulfuric acid and acetic acid with to the first mixture at a temperature of about 40 °C to about 300 °C to form a third mixture comprising an isotropic pitch composition, wherein the isotropic pitch composition comprises: at least two monomers linked with at least one methylene bridge between each one of the at least two monomers, wherein each one of the at least two monomers comprise one or more aromatic groups; wherein the isotropic pitch composition has a weight average molecular weight (Mw) of about 200 g / mol to about 1,500 g / mol. a softening point[4600-22401](Tsp) of 50 °C or greater, and a micro carbon residue (MCR) of about 5 wt.% or greater, based on a total weight of the isotropic pitch composition; and heating the isotropic pitch composition in an inert atmosphere to form a mesophase pitch composition.

[0104] Embodiment 13. The method of embodiment 12 wherein the aromatic feedstock comprises at least one unsubstituted aromatic compound and / or substituted aromatic compound selected from the group consisting of 1-ring aromatics (ARC1), 2-ring aromatics (ARC2), 3- ring aromatics (ARC3), 4 or more-ring aromatics (ARC4), 5-ring aromatics (ARC5), 6-ring aromatics (ARC6), 7-ring aromatics (ARC7), 8-ring aromatics (ARC8), 9-ring aromatics (ARC9), 10 or more-ring aromatics (ARC10+), and combinations thereof.

[0105] Embodiment 14. The method of any of embodiments 12-13 wherein the aromatic feedstock comprises at least one compound elected from the group consisting of a Cl to C20 hydrocarbyl monosubstituted aromatic, a Cl to C20 hydrocarbyl disubstituted aromatic, a Cl to C20 hydrocarbyl trisubstituted aromatic, and combinations thereof.

[0106] Embodiment 15. The method of any of embodiments 12-14, wherein the aromatic feedstock comprises partially hydrogenated aromatic rings.

[0107] Embodiment 16. The method of any of embodiments 12-15, wherein the aromatic feedstock comprises at least one compound selected from the group consisting of benzene, toluene, xylene, ethyl benzene, mesitylene, durane, naphthalene, 1 -methyl naphthalene, 2- methyl naphthalene, anthracene, phenanthrene, pyrene, benzopyrene, picenecoronene, chrysene, tetracene, pentacene, triphenylene. corannulene, benzo [j] fluoranthene, Benzo[c]fluorene, perylene, benzo-perylene, ovalene, and any combination thereof.

[0108] Embodiment 17. The method of any of embodiments 12-16 further comprising stabilizing the mesophase pitch composition by heating the mesophase pitch composition at a temperature below the softening point of the mesophase pitch in an atmosphere comprising oxygen to form a stabilized mesophase pitch composition.

[0109] Embodiment 18. The method of any of embodiments 12-17 further comprising heating the stabilized mesophase pitch composition at a carbonization temperature in an inert atmosphere to form a carbonaceous composition comprising amorphous carbon.

[0110] Embodiment 19. The method of any of embodiments 12-18 further comprising heating the carbonaceous composition at a graphitization temperature in an inert atmosphere to form a graphitic composition.

[0111] Embodiment 20. The method of any of embodiments 12-19 further comprising forming a battery anode comprising the graphitic composition.[4600-22401]

[0112] To facilitate a better understanding of the embodiments of the present disclosure, the following examples of preferred or representative embodiments are given. In no way should the following examples be read to limit, or to define, the scope of the present disclosure.EXAMPLES

[0113] In this example, isotropic pitch was prepared from an aromatic feed comprising mixed xylenes. The isotropic pitch was further converted to mesophase pitch and the mesophase pitch further converted to graphite.Preparation of Isotropic Pitch

[0114] Briefly, xylenes (1 mole equivalent) and paraformaldehyde (1 mole equivalent) were mixed in acetic acid in an around bottom flask. Sulfuric acid (0.75 mole equivalent) was added dropwise to the flask. The resulting mixture was stirred at 90 °C for 4 h and then cooled to ambient temperature and poured into water. The precipitates were filtered, ground and washed with water and dried under vacuum at 50 °C. The softening point of the isotropic pitch was found to be 122 °C.Preparation of Mesophase Pitch

[0115] The synthetic mesophase pitches were prepared by heating the isotropic pitches at 425 °C for 4 h in a nitrogen atmosphere. It was found that the mesophase content of the synthetic mesophase pitch was 95% and the softening point was greater than 400 °C. FIG. 4 is an optical micrograph of mesophase pitch produced via thermal treatment of the synthetic pitch product for 4 different durations at 425 °C. The pitch material was prepared for optical imaging by embedding it in epoxy and polishing it until reaching a mirror-smooth surface. Before the heat treatment, the starting isotropic pitch did not display any anisotropic optical texture or mesophase droplets. However, after thermal processing for 4 hours at 425 °C, optical micrographs indicate larger nematic droplets or nematic regions.Stabilization and Thermolysis

[0116] The mesophase pitch was further stabilized by oxidation. The mesophase pitches were oxidized at 260 °C for 2 h with a heating rate of 1 °C / min in an air-circulated box furnace. The oxidized pitch was carbonized under a N2 atmosphere at 900 °C by using a heating rate of 5 °C / min in a tube-type furnace. Thermogravimetric analysis (TGA) was performed on the mesophase pitch, the oxidized mesophase pitch, and the carbonized mesophase pitch. The results of the TGA analysis are shown in FIG. 5.

[0117] FIG. 5 shows 3 curves with the first curve representing the synthetic mesophase pitch heated under air (labelled “Syn-MP in air’ in FIG. 5). While combustion starts at 260 °C, mass loss starts around 460 °C and complete mass loss occurs by 580 °C. The same mesophase pitch[4600-22401] was heated under nitrogen (labelled “Syn-MP in N2” in FIG. 5). While the mass loss starts around 350 °C, 20 % is lost by 500 °C, and 32 % is lost by 800 °C. In contrast, the synthetic mesophase pitch, which experienced oxidation at 260 °C (labelled “Syn-MP-oxid260C in N2” in FIG. 5) prior to the thermogravimetric analysis (TGA) in nitrogen, loses only 10 % by 500 °C, 20 % by 600 °C, 25 % by 700 °C, and 30 % by 800 °C. Therefore, the oxidation step according to embodiments of the present disclosure provides thermal stability to the synthetic mesophase pitch. It was further observed that the carbonized mesophase pitch did not puff during the carbonization.

[0118] The mesophase pitch was further carbonized at 900 °C, 1100 °C, 1300 °C, and 1500 °C and each pitch was analyzed by x-ray diffraction (XRD). The results of the XRD are shown in FIG. 6. It was observed that the increasing carbonization temperature led to a more graphitic structure as indicated by the spectrum of the carbonized pitch approaching that of natural graphite.

[0119] All documents described herein are incorporated by reference herein for purposes of all jurisdictions where such practice is allowed, including any priority documents and / or testing procedures to the extent they are not inconsistent with this text. As is apparent from the foregoing general description and the specific embodiments, while forms of the disclosure have been illustrated and described, various modifications can be made without departing from the spirit and scope of the disclosure. Accordingly, it is not intended that the disclosure be limited thereby. For example, the compositions described herein may be free of any component, or composition not expressly recited or disclosed herein. Any method may lack any step not recited or disclosed herein. Likewise, the term “comprising” is considered synonymous with the term “including.” Whenever a method, composition, element or group of elements is preceded with the transitional phrase “comprising,” it is understood that we also contemplate the same composition or group of elements with transitional phrases “consisting essentially of,” “consisting of,” “selected from the group of consisting of,” or “is” preceding the recitation of the composition, element, or elements and vice versa.

[0120] One or more illustrative incarnations incorporating one or more disclosure elements are presented herein. Not all features of a physical implementation are described or shown in this application for the sake of clarity. It is understood that in the development of a physical embodiment incorporating one or more elements of the present disclosure, numerous implementation-specific decisions must be made to achieve the developer's goals, such as compliance with system-related, business-related, government-related and other constraints, which vary by implementation and from time to time. While a developer's efforts might be[4600-22401] time-consuming, such efforts would be, nevertheless, a routine undertaking for those of ordinary skill in the art and having benefit of this disclosure.

[0121] Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weight, reaction conditions, and so forth used in the present specification and associated claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the embodiments of the present disclosure. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claim, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0122] Whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range is specifically disclosed, including the lower limit and upper limit. In particular, every range of values (of the form, “from about a to about b,” or, equivalently, “from approximately a to b,” or, equivalently, “from approximately a-b”) disclosed herein is to be understood to set forth every number and range encompassed within the broader range of values. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. Moreover, the indefinite articles “a” or “an,” as used in the claims, are defined herein to mean one or more than one of the element that it introduces.

[0123] Therefore, the present disclosure is well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the present disclosure may be modified and practiced in different but equivalent manners apparent to one having ordinary skill in the art and having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered, combined, or modified and all such variations are considered within the scope and spirit of the present disclosure. The embodiments illustratively disclosed herein suitably may be practiced in the absence of any element that is not specifically disclosed herein and / or any optional element disclosed herein.

Claims

2024EM154-US[4600-22400]CLAIMSWhat is claimed is:

1. A method comprising: heating an isotropic pitch composition in an inert atmosphere to form a mesophase pitch composition, wherein the isotropic pitch composition comprises: at least two monomers linked with at least one methylene bridge between each one of the at least two monomers, wherein each one of the at least two monomers comprises one or more aromatic groups comprising at least one 5-membered ring, 6-membered ring, or any combination thereof; and wherein the isotropic pitch composition has a weight average molecular weight (Mw) of about 200 g / mol to about 1,500 g / mol, a softening point (Tsp) of 50 °C or greater, and a micro carbon residue (MCR) of about 5 wt.% or greater, based on a total weight of the isotropic pitch composition.

2. The method of claim 1 wherein the mesophase pitch composition has a softening point at a point in a range of from about 200 °C to about 800 °C as measured according to ASTM D3104.

3. The method of any of claims 1-2 wherein the mesophase pitch composition has a glass transition temperature (Tg) at a point in a range of from about 100 °C to about 500 °C.

4. The method of any of claims 1-3 wherein the mesophase pitch composition has a micro carbon residue (MCR) of from about 5 wt. % to about 95 wt. %, based on a total weight of the mesophase pitch composition.

5. The method of any of claims 1-4 further comprising stabilizing the mesophase pitch composition by heating the mesophase pitch composition at a temperature below the softening point of the mesophase pitch in an atmosphere comprising oxygen to form a stabilized mesophase pitch composition.

6. The method of any of claims 1-5 wherein the oxygen is present in an amount of about 0.1 mol% to about 20 mol% in the atmosphere comprising oxygen.2024EM154-US[4600-22400]7. The method of any of claims 1-6 further comprising heating the stabilized mesophase pitch composition at a carbonization temperature in an inert atmosphere to form a carbonaceous composition comprising amorphous carbon.

8. The method of any of claims 1-7 wherein the stabilized mesophase pitch composition is heated to a temperature at a point in a range of from about 700°C to about 1800°C.

9. The method of any of claims 1-8 further comprising heating the carbonaceous composition at a graphitization temperature in an inert atmosphere to form a graphitic composition.

10. The method of any of claims 1-9 wherein the carbonaceous composition is heated to a temperature at a point in a range of from about 2000°C to about 3400°C.

11. A battery anode comprising the graphitic composition of claim 9.

12. A method comprising: mixing an aromatic feedstock comprising one or more aromatic compounds with at least one of formaldehyde, paraformaldehyde, or trioxane, in the presence of acetic acid to produce a first mixture; mixing a second mixture comprising sulfuric acid and acetic acid with to the first mixture at a temperature of about 40 °C to about 300 °C to form a third mixture comprising an isotropic pitch composition, wherein the isotropic pitch composition comprises: at least two monomers linked with at least one methylene bridge between each one of the at least two monomers, wherein each one of the at least two monomers comprise one or more aromatic groups; wherein the isotropic pitch composition has a weight average molecular weight (Mw) of about 200 g / mol to about 1,500 g / mol, a softening point (Tsp) of 50 °C or greater, and a micro carbon residue (MCR) of about 5 wt.% or greater, based on a total weight of the isotropic pitch composition; and heating the isotropic pitch composition in an inert atmosphere to form a mesophase pitch composition.

13. The method of claim 12 wherein the aromatic feedstock comprises at least one unsubstituted aromatic compound and / or substituted aromatic compound selected from the2024EM154-US[4600-22400] group consisting of 1-ring aromatics (ARC1), 2-ring aromatics (ARC2), 3-ring aromatics (ARC3), 4 or more-ring aromatics (ARC4), 5-ring aromatics (ARC5), 6-ring aromatics (ARC6), 7-ring aromatics (ARC7). 8-ring aromatics (ARC8), 9-ring aromatics (ARC9), 10 or more-ring aromatics (ARC10+), and combinations thereof.

14. The method of any of claims 12-13 wherein the aromatic feedstock comprises at least one compound elected from the group consisting of a Ci to C20 hydrocarbyl monosubstituted aromatic, a Ci to C20 hydrocarbyl disubstituted aromatic, a Ci to C20 hydrocarbyl trisubstituted aromatic, and combinations thereof.

15. The method of any of claims 12-14, wherein the aromatic feedstock comprises partially hydrogenated aromatic rings.

16. The method of any of claims 12-15, wherein the aromatic feedstock comprises at least one compound selected from the group consisting of benzene, toluene, xylene, ethyl benzene, mesilylene. durane. naphthalene, 1 -methyl naphthalene, 2-methyl naphthalene, anthracene, phenanthrene, pyrene, benzopyrene, picenecoronene, chrysene, tetracene, pentacene, triphenylene, corannulene, benzo[j]fluoranthene, Benzo[c]fluorene, perylene. benzo-perylene, ovalene, and any combination thereof.

17. The method of any of claims 12-16 further comprising stabilizing the mesophase pitch composition by heating the mesophase pitch composition at a temperature below the softening point of the mesophase pitch in an atmosphere comprising oxygen to form a stabilized mesophase pitch composition.

18. The method of any of claims 12-17 further comprising heating the stabilized mesophase pitch composition at a carbonization temperature in an inert atmosphere to form a carbonaceous composition comprising amorphous carbon.

19. The method of any of claims 12-18 further comprising heating the carbonaceous composition at a graphitization temperature in an inert atmosphere to form a graphitic composition.2024EM154-US[4600-22400]20. The method of any of claims 12-19 further comprising forming a battery anode comprising the graphitic composition.

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