A pitch-based composite powder containing a graphitization catalyst, and a method for producing and using the same.

Abstract

A composite powder for electrode manufacturing may be formed by blending a graphitization catalyst or its precursor with petroleum pitch under grinding conditions. The composite powder may contain about 0.1% to about 30% by mass of the graphitization catalyst or its precursor, and 20% to about 99.9% by mass of petroleum pitch, relative to the total mass of the composite powder. The graphitization catalyst or its precursor is dispersed in a matrix containing petroleum pitch, and the petroleum pitch contains multiple pitch particles. The composite powder may subsequently be carbonized and then graphitized under conditions that may not be more stringent than non-catalytic graphitization. The grinding conditions for forming the composite powder include melt blending to form a continuous pitch matrix, in which at least a portion of the graphitization catalyst or its precursor may be dispersed inside the pitch particles.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims priority to U.S. Provisional Patent Application No. 63 / 508,397, filed on Jun. 15, 2023, the entire disclosure of which is incorporated herein by reference in its entirety in relation to composite powders, more particularly composite powders containing or derived from petroleum pitch.

[0002] This disclosure relates to composite powders, more particularly composite powders containing or derived from petroleum pitch.

Background Art

[0003] Graphite is a carbon allotrope composed of a large number of stacked sheets of hybrid carbon arranged in a highly ordered structure. Among many beneficial properties, graphite has high thermal and electrical conductivity values, and due to the latter, graphite can be useful, inter alia, as an electrode material in, for example, batteries. Furthermore, the crystal structure of graphite promotes the ability to store lithium ions through intercalation, which is useful for lithium - ion battery applications. Further applications where graphite is widely used include, for example, fiber manufacturing, composite manufacturing, lubrication, and electrodes for electric arc furnaces. ​​Graphite can be obtained from natural resources or produced by synthesis through the thermal decomposition of carbonaceous precursors. The latter material is referred to herein as “synthetic graphite.” Suitable carbonaceous precursors for producing synthetic graphite include coke and petroleum pitch, each containing large aromatic molecules that can be converted to graphite under thermal decomposition conditions. For example, the large aromatic molecules in coke and petroleum pitch can first be converted to amorphous carbon in a carbonization process carried out at temperatures of approximately 700°C to 1800°C, and then the amorphous carbon can subsequently be converted to graphite in a graphitization process carried out at higher temperatures of approximately 2800°C to 3400°C. Both conversion processes are carried out in the absence or substantially absence of oxygen. To achieve a high conversion percentage of the previously formed amorphous carbon to graphite (e.g., more than 90% conversion of amorphous carbon to graphite by mass), temperatures of 3000°C or higher and long reaction times of up to approximately 20 hours are often required. Because such long-duration, high-temperature conversion processes are extremely energy-intensive, the production of synthetic graphite remains costly despite the low cost of graphite precursors such as coke and petroleum pitch. Industrial graphitization processes may utilize a further range of graphitization temperatures, which can affect the quality of the graphite produced by those processes.

[0004] The adoption of lithium-ion batteries has increased significantly due to their use in electric vehicles, stationary energy storage, and portable electronic devices. Synthetic graphite has become an optimal material for the negative electrode of lithium-ion batteries. Key considerations for the negative electrode include high volumetric and gravimetric capacity, long charge-discharge cycle life, and faster charging speeds. Graphite anode materials designed for high power capacity and performance, such as those used in EVs, require a protective amorphous carbon coating layer to protect the underlying graphite sheet from the electrolyte inside the cell. Furthermore, the graphite material for the negative electrode is often ground into particles of <10 microns in size and re-aggregated using a suitable carbonaceous binder such as petroleum pitch to form "secondary particles." The secondary particle graphite anode further protects the graphite sheet from electrolyte decomposition and lithium plating, especially during long cycles and rapid charging. The coating and binder themselves do not have lithium storage capacity but prevent the decomposition of the graphite. Coating the graphite anode and forming secondary particles requires separate continuous heat treatments at approximately 1100-1300°C, which increases overall manufacturing costs but reduces yield.

[0005] While attempts have been made to overcome these challenges using carbon-coated graphite anodes, research is also underway to develop graphite anode materials that incorporate nucleating agents. Conventional techniques have focused on incorporating graphitization catalysts or nucleating agents onto the surface of graphite precursors to lower the graphitization temperature and improve the cycle lifetime of graphite anodes. Due to the difficulty in dispersing the graphitization catalyst inside the particles, the nucleating agent reacts with carbon on the particle surface, forming carbide or nitride particles on the surface. The formed boron nitride has high insulating properties, which increases contact resistance and leads to side reactions of lithium and electrolytes. This disclosure overcomes these challenges by carefully selecting a graphitization catalyst that is incorporated not only on the surface but also internally into the graphite precursor. The inventors also describe a method for incorporating a graphite catalyst into a precursor and then graphitizing it at a temperature of 1800-3000°C to produce a final graphite anode having excellent discharge capacity, cycle lifetime, and rate performance. [Overview of the Initiative]

[0006] In various embodiments, the present disclosure provides a composite powder comprising about 0.1% to about 30% by mass of a graphitization catalyst or its precursor based on the total mass of the composite powder; and about 20% to about 99.9% by mass of petroleum pitch based on the total mass of the composite powder; wherein the graphitization catalyst or its precursor is dispersed in a matrix comprising petroleum pitch, and the petroleum pitch comprises a plurality of pitch particles. In some or other various embodiments, the Disclosure provides compositions comprising a graphitization catalyst dispersed in a carbon matrix in an amount of up to about 35% by mass of the total mass of the composition; wherein the carbon matrix comprises amorphous carbon.

[0007] In other embodiments, the method of the present disclosure comprises forming a blend containing about 0.1% to about 35% by mass of a graphitization catalyst or its precursor and about 20% to about 99.9% by mass of petroleum pitch, based on the total mass of the blend; and processing the blend under grinding conditions to form a composite powder; the graphitization catalyst is dispersed in a matrix containing petroleum pitch, and the petroleum pitch contains a plurality of pitch particles. Another object of this disclosure is to provide a negative electrode for a lithium-ion battery that has a large discharge capacity and exhibits remarkably low capacity loss during periodic charge-discharge cycles and during high-rate charge-discharge.

[0008] In other embodiments, the Disclosure provides a method for incorporating a graphitizing catalyst into a graphite precursor by melt-blending 0.1% to about 35% by mass of a graphitizing catalyst or precursor thereof and about 20% to about 99.9% by mass of petroleum pitch, each based on the total mass of the blend; and processing the resulting composite under grinding conditions to form a composite powder; wherein the graphitizing catalyst is dispersed in a matrix containing petroleum pitch, and the petroleum pitch comprises a plurality of pitch particles. In some or other various embodiments, the Disclosure provides a negative electrode for a metal-ion battery having a particle size in the range of 1 μm to 50 μm, formed from a composite powder containing 0.1% to 30% by mass of a graphitizing catalyst or precursor thereof and about 20% to about 99.9% by mass of petroleum pitch, each based on the total mass of the composite powder; wherein the graphitizing catalyst or precursor thereof is dispersed in a matrix containing petroleum pitch, and the petroleum pitch comprises a plurality of pitch particles graphitized at a temperature of 1800°C to 3000°C. In another embodiment, the graphitization catalyst can reduce the time required to achieve a degree of graphitization of >90%. High-rate graphitization allows for >80% graphitization at temperatures lower than standard temperatures (2800-3400°C). The compositions and methods disclosed in this disclosure, as well as their advantageous applications and / or uses, will become apparent from the following detailed description. The accompanying drawings are provided to assist those skilled in the art in constructing and using the subject matter herein. The following drawings are included to illustrate certain aspects of the disclosure and should not be considered exclusive. The disclosed subject matter is capable of any conceivable modifications, alterations, combinations, and equivalents of form and function, as can be recalled by those skilled in the art and those interested in the disclosure. [Brief explanation of the drawing]

[0009] [Figure 1A] This figure shows a composite powder in which a graphitization catalyst is dispersed between pitch particles, according to some embodiments of the present disclosure. [Figure 1B]This figure shows a composite powder in which the graphitization catalyst is located inside the pitch particles, according to some embodiments of the present disclosure. [Figure 1C] This figure shows a composite powder in which the graphitization catalyst is present both inside and between the pitch particles, according to some embodiments of the present disclosure. [Figure 2] [Figure 3] This is an X-ray diffraction pattern of a composite powder manufactured according to some embodiments of the present disclosure. [Figure 4] This is a graph of the degree of graphitization as a function of temperature for a composite powder manufactured according to some embodiments of this disclosure. [Figure 5] This is a graph of the capacity retention over a discharge cycle for an electrode manufactured according to some embodiments of the present disclosure. [Modes for carrying out the invention]

[0010] This disclosure relates to composite powders, and more particularly to composite powders containing or derived from petroleum pitch. It should be understood that the terms “pitch” and “petroleum pitch” are used interchangeably herein. Furthermore, it should be understood that “pitch particles” as described herein may contain petroleum pitch. As discussed above, graphite is a versatile material with numerous important applications due to its high electrical and thermal conductivity, as well as its crystalline structure which can facilitate lithium-ion intercalation. While graphite can be synthesized from inexpensive precursors such as coke and petroleum pitch, the process for producing synthetic graphite is typically very energy-intensive, resulting in high manufacturing costs. Furthermore, synthetic pitch-based graphite anodes often have limited capabilities for achieving high capacity, fast charging, and long cycle life.

[0011] This disclosure addresses, at least partially, the aforementioned problems using a novel method incorporating a graphitization catalyst or its precursor. A “graphitization catalyst” is a substance capable of facilitating the conversion of a precursor material to graphite under suitable pyrolysis conditions. A suitable graphitization catalyst can reduce the temperature and / or time required to produce synthetic graphite under pyrolysis conditions, or increase the amount of synthetic graphite produced under a given set of pyrolysis conditions. Precursors to graphitization catalysts can be converted to graphitization catalysts in the process of being heated under pyrolysis conditions. Unless otherwise specified or evident from the context of this disclosure, the term “graphitization catalyst” is used herein to refer interchangeably to a graphitization catalyst or a graphitization catalyst precursor.

[0012] More specifically, this disclosure provides easy access to a composite powder containing a graphitization catalyst dispersed in petroleum pitch. Petroleum pitch is a petroleum-derived, carbon-rich viscoelastic material that has properties similar to thermoplastic polymers due to having a softening temperature. Once manufactured, the composite powder can be readily molded into desired forms before being converted to amorphous carbon and subsequently graphite. The dispersion of the graphitization catalyst in the petroleum pitch can vary depending on whether the composite powder is formed above or below the softening temperature of the petroleum pitch. By processing the graphitization catalyst and petroleum pitch below the softening temperature, the graphitization catalyst can be dispersed in the void space around the pitch particles (including contact with the outer surface of the pitch particles), while by processing above the softening temperature, at least a portion of the graphitization catalyst can be dispersed inside the pitch particles after the collapse of the continuous pitch matrix. While any composite powder morphology may be effective in facilitating graphite production according to the disclosure herein, composite powders in which the graphitization catalyst is dispersed within the pitch particles facilitate more effective contact with the larger surface area of ​​petroleum pitch, thereby promoting a more effective conversion to graphite. Furthermore, the dispersed graphitization catalyst prevents the formation of nitrides and carbides, which can create high resistance and potentially act as insulating materials.

[0013] The production of the composite powders disclosed herein may be facilitated by utilizing grinding and / or pulverization processes (hereinafter referred to as “grinding” or “grinding process”). Methods for forming the composite powders include using continuous blending and grinding, which may or may not include first softening the petroleum pitch by heating it above its softening temperature. The grinding process may facilitate the dispersion of the graphitization catalyst within the petroleum pitch. Furthermore, a suitable grinding process may facilitate the conversion of larger pitch particles to smaller sizes and / or the conversion of the continuous pitch matrix into particle form. The graphitization catalyst may also undergo a reduction in size during the grinding process, possibly to nanoparticle form. As used herein, the term “nanoparticle form” refers to any size range of less than about 1000 nm, preferably less than about 500 nm, more preferably less than about 200 nm, or less than about 100 nm.

[0014] If the petroleum pitch is heated above its softening temperature during the production of the composite powder according to this disclosure, the blending process described herein may be referred to as a melt blending process. Conversely, if the petroleum pitch is kept below its softening temperature during the production of the composite powder, the blending process described herein may be referred to as a dry blending process. In both melt blending and dry blending processes, the blending process can be carried out continuously in a screw mill extruder or a similar type of extruder, and the resulting composite powder can, in most cases, be obtained directly from the extruder without the need for further grinding. Optionally, the composite powder may be sieved to a specific particle size if necessary or desired. Further optional, the dry blending process may be carried out using a cooled extruder (e.g., about -10°C to about 5°C) to keep the petroleum pitch in a solid state and limit the possibility of chemical decomposition. In this disclosure, the term “cold blending” is used to refer to a dry blending process carried out at room temperature (below 23°C) and below the softening temperature of the petroleum pitch being blended.

[0015] A variety of graphitization catalysts may be suitable for use in the present disclosure herein. By way of non-limiting example, suitable graphitization catalysts may promote graphitization through mechanisms including, but not limited to, diffusion and intercalation, carbon dissolution-precipitation, carbide formation-decomposition, or any combination thereof. The multiple mechanisms that promote graphite formation may act simultaneously either by using a single graphitization catalyst that promotes graphitization by multiple mechanisms or by utilizing two or more graphitization catalysts that promote graphite formation through different mechanisms. Further description regarding suitable graphitization catalysts is provided in more detail below. For the purposes of the present disclosure, a new numbering scheme for the groups of the periodic table is used. In said numbering scheme, the groups (columns) are numbered from 1 to 18 in order from left to right, excluding the f-block elements (lanthanides and actinides). In this scheme, the term "transition metal" refers to any atom in groups 3 - 12 of the periodic table.

[0016] Thus, the composite powder of the present disclosure may include a graphitization catalyst or a graphitization catalyst precursor blended with petroleum pitch, and the graphitization catalyst or graphitization catalyst precursor is dispersed in a matrix containing petroleum pitch, and the petroleum pitch includes a plurality of pitch particles. In a more specific example, the composite powder may include from about 0.1 wt% to about 30 wt% of a graphitization catalyst or its precursor, based on the total mass of the composite powder, and from about 20 wt% to about 99.9 wt% of petroleum pitch, based on the total mass of the composite powder.

[0017] As referenced above, the morphology of the composite powder can vary depending on whether the graphitizing catalyst is blended with petroleum pitch under melt blending conditions, dry blending conditions, or a combination thereof. In a dry blending process, the graphitizing catalyst can be dispersed in the composite powder by being positioned between pitch particles, for example, in the void spaces between pitch particles, such that the graphitizing catalyst is in contact with the outer surface of the pitch particles. Figure 1A is a diagram of composite powder 100A showing the graphitizing catalyst 102 dispersed between pitch particles 104 in void spaces 106 and / or located on the outer surface of the pitch particles 104. In contrast, in a melt blending process, it is possible to produce a composite powder in which at least a portion of the graphitizing catalyst is dispersed inside the pitch particles, and some of the graphitizing catalyst may be exposed on the surface of the pitch particles. Figure 1B shows a composite powder 100B in which the graphitization catalyst 102 is present inside the pitch particles 104, in which case the void space 106 is not occupied (as shown in Figure 1B), or some of the graphitization catalyst 102 may be present in the void space 106 and / or embedded on the outer surface of the pitch particles 104 (Figure 1C). Optionally, a further dry blend of the composite powder 100B and a second portion of the graphitization catalyst 102 may be performed so that at least some of the void space 106 is filled with the graphitization catalyst (further filling is not shown in Figure 1B). Figure 1C shows a composite powder 100C in which the graphitization catalyst 102 is present inside the pitch particles 104 and also in the void space 106, and the void space 106 is filled either during the melt blending process or during a further dry blending process following the melt blending process. Although the pitch particles 104 and the graphitization catalyst 102 are shown as round, separate particles of the same size in Figures 1A-1C, it should be noted that the particle shapes can be irregular, and the particle size range may be shown for both the graphitization catalyst 102 and the pitch particles 104.

[0018] More specifically, the composite powder of the present disclosure may contain a graphitization catalyst of up to about 10% by mass, or up to about 15% by mass, or up to about 20% by mass, or up to about 25% by mass, or up to about 30% by mass, and about 20% by mass to about 99.9% by mass of petroleum pitch, based on the total mass of the composite powder. The graphitization catalyst is dispersed in a matrix containing petroleum pitch, and the petroleum pitch contains a plurality of pitch particles. In non-limiting examples, the composite powder may contain a graphitization catalyst or a precursor thereof in an amount of about 0.1% by mass to about 15% by mass, or about 0.1% by mass to about 15% by mass, or about 0.1% by mass to about 5% by mass, or about 1% by mass to about 15% by mass, or about 1% by mass to about 10% by mass, or about 1% by mass to about 5% by mass, or about 2% by mass to about 30% by mass, or 3% by mass to about 25% by mass, or about 3% by mass to about 20% by mass, or about 4% by mass to about 20% by mass, or about 5% by mass to about 15% by mass, or about 10% by mass to about 20% by mass, or about 3% by mass to about 10% by mass, based on the total mass of the composite powder. In some or other non-limiting examples, the composite powder may contain petroleum pitch in an amount of about 25% by mass to about 99.9% by mass, or about 30% by mass to about 80% by mass, or about 40% by mass to about 75% by mass, or about 30% by mass to about 50% by mass, or about 50% by mass to about 70% by mass, or about 70% by mass to about 90% by mass, or about 80% by mass to about 98% by mass, or about 85% by mass to about 99% by mass, or about 90% by mass to about 99.9% by mass, based on the total mass of the composite powder.

[0019] The petroleum pitch used in this disclosure can be obtained from any source or process, provided that the petroleum pitch does not contain any components that may adversely affect the intended application of the composite powder after carbonization or graphitization. In some examples, at least the majority of the petroleum pitch may include mesophase pitch. Mesophase pitch is an anisotropic pitch containing a composite mixture of aromatic molecules that are at least partially ordered and fused to a liquid crystal phase. Crystallinity can enhance, for example, mechanical integrity. Furthermore, when carbonized and converted to graphite, the highly ordered structure can promote enhanced electrical conductivity and facilitate the formation of an ordered lattice structure in the graphite itself. In non-limiting examples, the petroleum pitch used herein may each have a mesophase pitch content of about 50% by mass or more, or about 60% by mass or more, or about 70% by mass or more, or about 80% by mass or more, or about 90% by mass or more, or about 95% by mass or more, or about 99% by mass or more, or about 99.9% by mass or more, for example, about 80% by mass to about 99.9% by mass, or about 90% by mass to about 99.9% by mass, or about 95% by mass to about 99.9% by mass, or even 100% by mass, based on the total mass of the petroleum pitch.

[0020] Suitable graphitization catalysts can facilitate the conversion of petroleum pitch to graphite by one or more mechanisms, including but not limited to diffusion and intercalation, carbon dissolution-precipitation, carbide formation-decomposition, or any combination thereof. The graphitization catalyst may be directly dispersed in a matrix containing pitch particles, or a precursor to the graphitization catalyst may be utilized. The graphitization catalyst precursor may undergo chemical reactions, including decomposition, to produce an active graphitization catalyst in the process of being heated to a desired carbonization temperature and / or graphitization temperature. Suitable graphitization catalysts may lower the temperature required to convert amorphous carbon to graphite, reduce the amount of time required to convert amorphous carbon to graphite, increase the amount of amorphous carbon converted to graphite, or any combination thereof, any or all of which can facilitate graphite production with reduced energy consumption compared to the conversion of petroleum pitch to graphite under non-catalytic conditions. Furthermore, by having a larger proportion of the graphitization catalyst within the pitch matrix, energy consumption can be minimized while further accelerating graphite production, compared to when the catalyst is located on the pitch surface, due to improved dispersion quality and limited nitride and carbide formation.

[0021] In some cases, a suitable graphitization catalyst may enhance graphitization through the diffusion constants of one or more of its elements. Without being bound by theory or mechanism, elements having diffusion constants greater than carbon in both the transverse and longitudinal directions may enhance the graphitization of petroleum pitch and similar graphite precursors by intercalating between aromatic rings in adjacent layers, thereby improving the graphitization rate by creating larger voids that carbon can utilize through self-diffusion. Suitable graphitization catalysts that can promote graphitization through intercalation and diffusion include those containing Group 13 elements. Examples of Group 13 elements include boron, aluminum, gallium, indium, and thallium. In a preferred example, a suitable graphitization catalyst containing Group 13 elements may also contain boron. Suitable boron-containing graphitization catalysts include, but are not limited to, boric acid, organic esters of boric acid, sodium tetraborate, tetrahydroxyborate, orthoborate, metaborate, triborate, tetraborate, pentaborate, octaborate, boronic acid, boronic acid esters, boron oxide, boron carbide, etc., or any combination thereof.

[0022] In some cases, a suitable graphitization catalyst may promote graphitization by a diffusion-precipitation mechanism (i.e., a carbon diffusion-precipitation mechanism). Without being bound by theory or mechanism, a graphitization catalyst that promotes graphitization by diffusion-precipitation may dissolve carbon (e.g., amorphous carbon) and then redeposit the dissolved carbon into a regular graphite layer. Suitable graphitization catalysts that can promote graphitization through dissolution and precipitation include those containing group 8-10 elements. Group 8-10 elements include iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium, and platinum. In preferred examples, a suitable graphitization catalyst containing group 8-10 elements may include iron, cobalt, or nickel. Suitable graphitization catalysts containing group 8-10 elements include, but are not limited to, Fe2O3, Fe3O4, Fe metal, Co metal, Ni metal, Fe-Ni alloy, Co-Ni alloy, Fe-Co alloy, Ni-Co alloy, iron carbide, etc., or any combination thereof.

[0023] In some cases, a suitable graphitization catalyst may promote graphitization through a carbide formation-decomposition mechanism. Regardless of theory or mechanism, a graphitization catalyst that promotes graphitization through carbide formation-decomposition may form initial metal carbide reaction products that subsequently decompose to produce graphite and free metals. Suitable graphitization catalysts that can promote graphitization through carbide formation include those containing group 4-7 elements. Examples of group 4-7 elements include titanium, vanadium, chromium, manganese, zirconium, niobium, molybdenum, hafnium, tantalum, tungsten, and rhenium. In preferred examples, a suitable graphitization catalyst containing group 4-7 elements may include titanium, vanadium, chromium, or manganese. Suitable graphitization catalysts containing group 4-7 elements include, but are not limited to, Ti metal, V metal, Cr metal, Mn metal, titanium oxide, vanadium oxide, chromium oxide, and manganese dioxide.

[0024] Further graphitization catalysts that may be suitable for use in this specification include, for example, Group 2 elements such as beryllium, calcium, magnesium, strontium, and barium; Group 11 elements such as copper, silver, and gold; Group 12 elements such as zinc; and Group 14 elements such as silicon. Therefore, the graphitization catalyst or its precursor may include a compound containing at least one of the following elements: Group 2, Group 4, Group 5, Group 6, Group 7, Group 8, Group 9, Group 10, Group 13, Cu, Zn, or Si. Suitable compounds containing elements from the aforementioned groups of the periodic table include, but are not limited to, oxides, carbides, salts, coordination compounds, and any combination thereof.

[0025] When blended with petroleum pitch, the graphitization catalyst may have any suitable size and any suitable particle size distribution that provides sufficient contact with the pitch matrix to promote its graphitization after carbonization. For example, a graphitization catalyst blended with petroleum pitch may have a D50 of about 200 nm or less, or about 300 nm or less, or about 500 nm or less, and a D90 of about 1000 nm or less, or about 1200 nm or less, or about 1500 nm or less. As used herein, the term "D50" refers to a diameter in which 50% of the sample by volume consists of particles having a diameter less than the aforementioned diameter. As used herein, the term "D90" refers to a diameter in which 90% of the sample by volume consists of particles having a diameter less than the aforementioned diameter. Examples of particle size distributions of graphitization catalysts used herein include D50 with particle sizes of approximately 10 nm to approximately 300 nm, or approximately 50 nm to approximately 250 nm, or approximately 100 nm to approximately 200 nm, or approximately 1 nm to approximately 200 nm, and / or D90 with particle sizes of approximately 10 nm to approximately 1200 nm, or approximately 10 nm to approximately 1000 nm, or approximately 10 nm to approximately 900 nm, or approximately 700 nm to approximately 1100 nm.

[0026] In some or other examples, at least the majority, preferably 75% or more, or even 90% or more, of the graphitization catalyst present in the composite powder may have a size in the range of about 25 nm to about 200 nm, or about 50 nm to about 150 nm, or about 50 nm to about 100 nm, or about 50 nm to about 75 nm, or about 75 nm to about 100 nm, or about 75 nm to about 125 nm, or about 125 nm to about 175 nm. It should be noted that since the graphitization catalyst may undergo particle size reduction under the grinding process used to produce the composite powder according to further descriptions herein, graphitization catalysts having larger particle sizes than those described above can be used to produce the composite powder disclosed herein. For example, when the graphitization catalyst is processed in a grinding process for producing the composite powder disclosed herein, it may have a size of up to about 500 nm, or up to about 1 micron, or up to about 5 microns, or up to about 10 microns before undergoing particle size reduction. Similarly, petroleum pitch may undergo particle size reduction when processed with a blend of petroleum pitch and graphitization catalyst under suitable grinding conditions. Therefore, the composite powders of this disclosure may contain petroleum pitch particles having particle sizes in the range of at least about 1 μm to about 50 μm, or about 5 μm to about 50 μm, or about 5 μm to about 25 μm, or about 10 μm to about 30 μm. The particle size is measured by laser diffraction using a particle size analyzer via both dry and wet methods. The dry method consists of directly measuring the powder, while the wet method involves dispersing the powder in a solvent such as mineral oil at a maximum of 5% by mass.

[0027] The composite powders of this disclosure may further contain graphite, which may be introduced when a graphitization catalyst is blended with petroleum pitch to form the composite powder, or the graphite may be subsequently mixed with the composite powder. In non-limiting examples, the composite powder may contain graphite in amounts ranging from about 0.1% to about 85% by mass, or about 0.1% to about 60% by mass, or about 5% to about 60% by mass, or about 5% to about 20% by mass, or about 20% to about 40% by mass, or about 30% to about 60% by mass, or about 5% to about 20% by mass, or about 20% to about 50% by mass, based on the total mass of the composite powder. Similar to the graphitization catalyst, when present in the composite powder, the graphite may be located outside the pitch particles (e.g., in the interstitial spaces between pitch particles, including on the outer surface of the pitch particles) if the composite powder is prepared by a dry blending process, or inside the pitch particles if the composite powder is prepared by a melt blending process. In some cases, the added graphite present in the composite powder may be upgraded by an increase in its graphitization percentage after the composite powder is carbonized and subsequently graphitized in the presence of a graphitization catalyst. Without being bound by theory or mechanism, graphitization catalysts may facilitate such an upgrade of added graphite.

[0028] Furthermore, in some examples, the composite powder may be further treated after incorporating a graphitization catalyst (and optionally graphite) but before carbonizing and / or graphitizing the petroleum pitch within the composite powder. In particular, the composite powder may be heated below the softening temperature of petroleum pitch in a low-oxygen environment (e.g., about 0.1 mol% to about 20 mol% oxygen). At least some oxidation of petroleum pitch carried out under such conditions may provide some benefits. That is, when petroleum pitch is heated below its softening temperature in a low-oxygen environment, the mechanical integrity of the composite powder and the resulting carbon matrix may be enhanced through at least partial crosslinking of the petroleum pitch. At least partial crosslinking may also raise the softening temperature of the petroleum pitch, thereby making it easier to maintain the shape of the composite powder as it is heated during carbonization or graphitization. Furthermore, if at least a portion of the graphitization catalyst is located on the outer surface of the pitch particles and / or within the interstitial spaces between the pitch particles, the graphitization catalyst can be at least partially embedded on the outer surface of the pitch particles being treated under such conditions.

[0029] In non-limiting examples, heating below the softening temperature described above may be carried out at temperatures above room temperature and below about 500°C, or below about 400°C, or below about 300°C, or below about 200°C, for example, within the 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. The actual heating temperature may be selected based on the initial softening temperature of the petroleum pitch. The low-oxygen environment may have an oxygen concentration in the range of 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%. Therefore, in some cases, the composite powder may be heated in an environment containing about 0.1 mol% to about 20 mol% oxygen at temperatures ranging from about 200°C to about 450°C, or from about 200°C to about 300°C, or from about 300°C to about 450°C, or from about 250°C to about 400°C. When heated under the aforementioned conditions, crosslinking of at least a portion of the petroleum pitch may occur. A simultaneous increase in the softening temperature may occur during the crosslinking of the petroleum pitch.

[0030] The above-mentioned composite powder can serve as a precursor composite to form a carbon composite in which petroleum pitch is thermally decomposed (carbonized) to form a carbon matrix containing amorphous carbon and / or graphite. Amorphous carbon can be distinguished from graphite by spectroscopic methods, for example, by powder X-ray diffraction. The conversion of the composite powder to a graphite-containing composite may occur along with the initial conversion of petroleum pitch to amorphous carbon in a first heating temperature followed by a second heating temperature higher than the first heating temperature to form graphite, with each heating operation carried out under conditions that minimize reaction with oxygen. Amorphous carbon can be formed when petroleum pitch is exposed to temperatures in the range of 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 an oxygen-free or very low-oxygen environment (e.g., with an oxygen content of about 0.1 mol% or less), preferably in the presence of an inert gas environment. Thus, in some examples, the composite powder can be at least partially carbonized in an environment containing about 0.1 mol% or less oxygen at carbonization temperatures in the range of about 700°C to about 1800°C or about 900°C to about 1500°C, thereby at least partially converting the petroleum pitch into amorphous carbon.

[0031] After converting petroleum pitch to amorphous carbon, graphitization of the composite powder may then occur. Under non-catalytic conditions, graphite can be formed from amorphous carbon by heating to higher temperatures in the range of about 2800°C to about 3400°C or about 2800°C to about 3000°C for a period of time that may range from up to about 24 hours, up to about 48 hours, or even up to about 72 hours, in an oxygen-free or very low-oxygen environment, preferably in the presence of an inert gas environment. By using the graphitization catalysts disclosed herein, an increase in graphite yield can be achieved at lower heating temperatures and / or for shorter heating times.

[0032] In non-limiting examples, the graphitization of the composite powders disclosed herein may be carried out at graphitization temperatures up to about 3400°C, for example, in the range of 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 below about 2000°C but above the carbonization temperature. When using the graphitization catalysts disclosed herein, about 80% by mass or more, or about 85% by mass or more, or about 90% by mass or more, or about 90% by mass or more of petroleum pitch in the composite powder may be converted to graphite. Under the aforementioned conditions, the duration of graphitization may be approximately 18 hours or less, or approximately 15 hours or less, or approximately 12 hours or less, or approximately 10 hours or less, or approximately 9 hours or less, or approximately 8 hours or less, or approximately 7 hours or less, or approximately 6 hours or less, or approximately 5 hours or less, or approximately 4 hours or less, or approximately 3 hours or less, or approximately 2 hours or less, or approximately 1 hour or less. In some cases, graphitization may be carried out at a graphitization temperature of approximately 3000°C to approximately 3400°C, but over a short graphitization time of approximately 1 hour or less, or approximately 50 minutes or less, or approximately 40 minutes or less, or approximately 30 minutes or less, or approximately 20 minutes or less, or approximately 10 minutes or less. Therefore, in at least some cases, after at least partially carbonizing the composite powder, heating above the carbonization temperature may be carried out in an oxygen-free or very low-oxygen environment containing 0.1 mol% or less of oxygen, to convert at least a portion of the amorphous carbon into graphite.

[0033] The composition obtained from the initial carbonization of petroleum pitch to form amorphous carbon may be isolated and / or analyzed before the subsequent conversion to graphite takes place. Such a composition may contain up to about 35% by mass of a graphitization catalyst dispersed in a carbon matrix, relative to the total mass of the composition, the carbon matrix containing at least amorphous carbon. Alternatively, the composition obtained after carbonization may be directly heated to the graphitization temperature without further cooling after carbonization. In other words, the carbonization and graphitization of the composite powder can, in some examples, be carried out in a single heating operation. Accordingly, such compositions can be produced by a process comprising heating petroleum pitch to a carbonization temperature sufficient to form a carbon matrix in an oxygen-free or very low-oxygen environment containing about 0.1 mol% or less of oxygen, where any graphitization catalyst precursor, if present, is converted to a graphitization catalyst during the formation of the carbon matrix. The petroleum pitch or amorphous carbon may be further converted to graphite at a suitable graphitization temperature, as will be discussed further herein. In any case, heating may be carried out in an environment containing about 0.1 mol% or less of oxygen.

[0034] When a composite powder is carbonized to form a carbon matrix, a small amount of mass loss may occur. Without being bound by theory or mechanism, the mass loss is considered to be the result of various reactions of petroleum pitch that form gaseous products. Such reactions include, for example, dehydrogenation, polymerization and / or hydrogen production by side chain loss, dealkylation, condensation of aromatic rings, and decomposition of oxygen-containing groups. Gaseous products include, for example, carbon monoxide, carbon dioxide, water vapor, hydrocarbon vapor, methane, etc. Up to about 20% by mass of petroleum pitch may be lost due to oxidation during carbonization. Preferably, the amount of such mass loss is about 10% by mass or less, or about 5% by mass or less, or about 2% by mass or less. Due to such mass loss occurring during carbonization, the corresponding amount of graphitization catalyst packed into the carbon matrix can increase, for example, up to about 35% by mass relative to the total mass of the resulting carbon matrix.

[0035] The methods of the present disclosure may provide a composite powder, a composition produced from the composite powder containing a carbon matrix containing amorphous carbon, or a composition produced from the composite powder containing a carbon matrix containing graphite. As mentioned above, the composite powder can be produced under grinding conditions suitable for dispersing a graphitization catalyst or its precursor in the form of multiple pitch particles in a matrix containing petroleum pitch. Such a method may include forming a blend each containing about 0.1% to about 30% by mass of a graphitization catalyst or its precursor and 20% to 99.9% by mass of petroleum pitch, based on the total mass of the blend; and processing the blend under grinding conditions to form a composite powder; the graphitization catalyst is dispersed in a matrix containing petroleum pitch, and the petroleum pitch contains multiple pitch particles.

[0036] In some cases, the composite powder may be produced by a dry blending process. Suitable dry blending processes for producing the composite powders described herein enable single-step processing of the materials while ensuring appropriate particle sizes and complete dispersion of the graphitization catalyst between pitch particles. Dry blending processes, preferably cold blending processes, can combine the graphitization catalyst and petroleum pitch in a manner that maintains the petroleum pitch below its softening temperature while dispersing the graphitization catalyst particles between multiple pitch particles. Combining the petroleum pitch and graphitization catalyst in the manner described above may include milling, extrusion, grinding, or any combination thereof. A reduction in the particle size of the petroleum pitch and / or graphitization catalyst may occur during such dry blending processes.

[0037] In non-limiting examples of preferred dry blending processes, the composite powders disclosed herein may be formed by milling or grinding a preferred petroleum pitch and a preferred graphitizing catalyst, preferably in a continuous milling or grinding process, more preferably in a screw mill extruder. Without being bound by theory, milling or grinding can preferably disperse the graphitizing catalyst and petroleum pitch together into a sufficiently dispersed particle state, while simultaneously reducing the particle size of individual components (e.g., graphitizing catalyst and petroleum pitch) within the composite powder. Therefore, the graphitizing catalyst and petroleum pitch introduced into the screw mill extruder do not necessarily have to be within the final size range present in the composite powder. For example, the graphitizing catalyst introduced into the screw mill extruder may be up to about 10 microns in size, or up to about 5 microns in size, or up to about 1 micron in size, or up to about 500 nm in size, and will undergo a size reduction as blending takes place. The screw mill can be any preferred size and configuration to achieve the desired degree of dispersion of the graphitizing catalyst within the petroleum pitch and the desired particle size. It should also be noted that composite powders can be produced by related grinding processes, such as ball milling, which are discontinuous (batch) processes.

[0038] In some cases, the composite powder may preferably be produced by a melt blending process, in which the graphitization catalyst may be blended with the petroleum pitch at a temperature above the softening temperature of the petroleum pitch. In non-limiting cases, heating during the melt blending process may be carried out at temperatures above the softening temperature and up to about 500°C, or up to about 400°C, or up to about 350°C, or up to about 325°C, for example, in the range of about 300°C to about 500°C, or about 325°C to about 450°C, or about 350°C to about 425°C, or about 350°C to about 475°C. In treating the graphitization catalyst with petroleum pitch in this manner, at least a portion of the graphitization catalyst may be dispersed in a continuous pitch matrix containing softened petroleum pitch. Similar to the dry blending process, the graphitization catalyst may undergo a change in particle size as blending with petroleum pitch occurs. Once the desired blending is performed and the graphitization catalyst is dispersed within the petroleum pitch, the resulting molten blend containing the continuous pitch matrix can be cooled to a temperature below the softening temperature, at which point the continuous pitch matrix can be divided into multiple pitch particles, each containing the graphitization catalyst within the pitch particles.

[0039] A suitable melt blending process can be carried out in an extruder in a manner similar to the associated dry blending process, except that the petroleum pitch is initially heated above its softening temperature, and then cooled below its softening temperature once the graphitizing catalyst is completely dispersed within the continuous pitch matrix. Heating can be carried out in a multi-zone extruder having a first zone maintained at a temperature above the softening temperature of the petroleum pitch and a second zone maintained at a temperature below the softening temperature of the petroleum pitch. Such a melt blending process can also be carried out in a screw mill extruder under continuous grinding conditions, or alternatively, in a batch process using a ball or sand mill above the softening temperature of the petroleum pitch, followed by cooling and grinding of the continuous pitch matrix to form a composite powder.

[0040] It should be noted that combined grinding processes are also contemplated in this disclosure. For example, two or more extruders may be used in series to achieve a blend of a desired particle size or degree, and / or two or more extruders may be used in parallel to increase throughput. In another example, two or more extruders may be used in series at different temperatures, with the first extruder forming a continuous pitch matrix containing dispersed graphitization catalyst above the softening temperature of petroleum pitch, and the second extruder grinding the continuous pitch matrix into a composite powder below the softening temperature of petroleum pitch. Furthermore, it should be noted that a melt blending process achieves higher quality dispersion by having more graphitization catalyst inside the pitch particles. In yet another example, a dry blending process may follow a melt blending process to produce a composite powder in which the graphitization catalyst is dispersed both inside and between the pitch particles.

[0041] After processing to achieve an appropriate particle size distribution and temperature, the composite electrode powder is added to an aqueous solution with a maximum solid content of 97% by mass. Additional conductive additives and binders are added with a maximum content of 10% by mass. The solution is then mixed to achieve good dispersion. The resulting slurry is coated onto copper foil, which is the current collector, dried into a film, and calendered to produce a negative electrode (i.e., anode) with a maximum of 15 layers and a total film thickness of up to 150 μm. The anode electrode sheet is added to the cathode with a separator film in between and pressed together into a pouch cell. Finally, the resulting cell is filled with an electrolyte made from a combination of carbonates (ethyl, ethylmethyl, dimethyl, etc.) and lithium salts (LiPO2F2, LiBF4, LiBOB, LiPF6, LiFSI, LiTFSI, etc.). Embodiments disclosed herein include the following:

[0042] A. Composite powder. The composite powder contains approximately 0.1% to 30% by mass of graphitization catalyst or its precursor relative to the total mass of the composite powder; and approximately 20% to 99.9% by mass of petroleum pitch relative to the total mass of the composite powder; the graphitization catalyst or its precursor is dispersed in a matrix containing petroleum pitch, and the petroleum pitch contains multiple pitch particles. B. Composition obtained from the composite powder. The composition contains a graphitization catalyst dispersed in a carbon matrix at a maximum of about 35% by mass relative to the total mass of the composition, the carbon matrix containing amorphous carbon. Composition B1. Composed of B, which is produced by a process comprising preparing a composite powder of A and heating petroleum pitch in an environment containing about 0.1 mol% or less of oxygen to a carbonization temperature sufficient to form a carbon matrix; and, if present, a graphitization catalyst precursor is converted to a graphitization catalyst during carbon matrix formation. C. Method for producing a composite powder. The method comprises forming a blend containing about 0.1% to about 35% by mass of a graphitization catalyst or its precursor and about 20% to about 99.9% by mass of petroleum pitch, based on the total mass of each blend; and processing the blend under grinding conditions to form a composite powder; wherein the graphitization catalyst is dispersed in a matrix containing petroleum pitch, and the petroleum pitch contains a plurality of pitch particles.

[0043] Embodiments A to C may have one or more of the following additional elements in any combination. Element 1: Petroleum pitch contains approximately 50% or more by mass of mesophase pitch. Element 2: The graphitization catalyst or its precursor is dispersed in the interstitial space between pitch particles. Element 3: At least a portion of the graphitization catalyst or its precursor is dispersed inside the pitch particles. Element 4: The pitch particles have a particle size in the range of approximately 1 μm to approximately 25 μm. Element 5: The composite powder contains approximately 0.1% to 10% by mass of the graphitization catalyst. Element 6: The graphitization catalyst or its precursor contains a compound that includes at least one of the following: Group 2 elements, Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, Group 9 elements, Group 10 elements, Group 13 elements, Cu, Zn, or Si. Element 7: The graphitization catalyst or its precursor comprises an oxide, carbide, salt, coordination compound, or any combination thereof. Element 8: The graphitization catalyst or its precursor contains compounds containing boron, iron, nickel, cobalt, molybdenum, titanium, zirconium, manganese, and vanadium. Element 9: The boron-containing compound comprises at least one compound selected from the group consisting of boric acid, sodium tetraborate, tetrahydroxyborate, orthoborate, metaborate, triborate, tetraborate, pentaborate, octaborate, boronic acid, boronic acid ester, boron oxide, boron carbide, and combinations thereof.

[0044] Element 10: The carbonization temperature is in the range of approximately 700°C to approximately 1800°C. Element 11: Forming a blend includes melt-blending a graphitization catalyst or its precursor and petroleum pitch at a temperature above the softening temperature of the petroleum pitch to disperse the graphitization catalyst or its precursor in a continuous pitch matrix, and processing the blend under grinding conditions includes grinding the continuous pitch matrix to form pitch particles in which at least a portion of the graphitization catalyst or its precursor is dispersed inside the pitch particles. Element 12: The method further comprises heating the composite powder in an environment containing about 0.1 mol% to about 20 mol% oxygen at a temperature in the range of about 200°C to about 450°C. Element 13: The method further comprises at least partially carbonizing a composite powder at a carbonization temperature in the range of about 700°C to about 1800°C in an environment containing about 0.1 mol% or less of oxygen, thereby at least partially converting petroleum pitch to amorphous carbon. Element 14: The method further comprises at least partially carbonizing a composite powder, and then heating it in an environment containing about 0.1 mol% or less of oxygen at a graphitization temperature above the carbonization temperature to convert at least a portion of the amorphous carbon into graphite. Element 15: Approximately 80% or more by mass of petroleum pitch in the composite powder is converted to graphite. Element 16: The graphitization temperature is in the range of approximately 2000°C to approximately 3400°C. Element 17: Heating at the graphitization temperature is performed for approximately 0.1 hours to approximately 5 hours.

[0045] As an example of non-limiting examples, exemplary combinations applicable to A-C include: 1 and 2; 1 and 3; 1-3; 1 and 4; 1 and 5; 1 and 6; 1 and 7; 1, 7, and 8; 1 and 11; 1 and 12; 1, 11, and 12; 1 and 13; 1, 11, and 13; 1 and 11-13; 1 and 14; 1 and 11-14; 1, 11, 13, and 14; 2 and / or 3, and 4; 2 and / or 3, and 5; 2 and / or 3, and 6; 2 and / or 3, and 7; 2 and / or 3, 7, and 8; 2 and / or 3, and 11; 2 and / or 3, and 12; 2 and / or 3, 11, and 12; 2 and / or 3, and 13; 2 and / or 3, 11, and 13; 2 and / or 3, and 11-13; 2 and / or 3, and 14; 2 and / or 3, and 11-14; 2 and / or 3, 11, and 13; 2 and / or 3, 11, 13, and 14; 4 and 5; 4 and 6; 4 and 7; 4, 7, and 8; 4 and 11; 4 and 12; 4, 11, and 12; 4 and 13; 4, 11, and 13; 4 and 11-13; 4 and 14; 4 and 11-14; 4, 11, and 13;4, 11, 13, and 14;5 and 6;5 and 7;5, 7, and 8;5 and 11;5 and 12;5, 11, and 12;5 and 13;5 and 11-13;5 and 14;5 and 11-14;5, 11, and 13;5, 11, 13, and 14;6 and 7;6-8;6 and 11;6 and 12;6, 11, and 12;6 and 13;6 and 11-13;6 and 14;6 and 11-14;6, 11, and 13;6, 11, 13, and 14;7 and 8;7 and 11;7 and 12;7, 11, and 12;7 and 13; Examples include, but are not limited to, 7, 11, and 13; 7 and 11-13; 7 and 14; 7 and 11-14; 7, 11, 13, and 14; 8 and 11; 8 and 12; 8, 11, and 12; 8 and 13; 8, 11, and 13; 8 and 11-13; 8 and 14; 8 and 11-14; 8, 11, 13, and 14; 12 and 13; 12-14; 12 and 14; 12-15; 12-16; 13 and 14; 13-15; 13-16; 13-17; 14 and 15; 14 and 16; 14-16; and 14-17.

[0046] Further embodiments disclosed herein include: Embodiment 1. A graphitization catalyst or its precursor in an amount of approximately 0.1% to 30% by mass relative to the total mass of the composite powder; Approximately 20% to 99.9% by mass of petroleum pitch relative to the total mass of the composite powder. A composite powder containing; A composite powder comprising a graphitization catalyst or its precursor dispersed in a matrix containing petroleum pitch, wherein the petroleum pitch contains multiple pitch particles. Embodiment 2. The composite powder of Embodiment 1, wherein the petroleum pitch contains approximately 50% by mass or more of mesophase pitch. Embodiment 3. A composite powder according to Embodiment 1 or Embodiment 2, wherein the graphitization catalyst or its precursor is dispersed in the interstitial spaces between pitch particles. Embodiment 4. A composite powder according to Embodiment 1 or Embodiment 2, wherein at least a portion of the graphitization catalyst or its precursor is dispersed inside the pitch particles.

[0047] Embodiment 5. A composite powder of any one of Embodiments 1 to 4, wherein the pitch particles have a particle size in the range of approximately 1 μm to approximately 25 μm. Embodiment 6. A composite powder of any one of Embodiments 1 to 5, containing approximately 0.1% to 10% by mass of a graphitization catalyst. Embodiment 7. A composite powder according to any one of Embodiments 1 to 6, wherein the graphitization catalyst or precursor thereof comprises a compound containing at least one of the following: Group 2 elements, Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, Group 9 elements, Group 10 elements, Group 13 elements, Cu, Zn, or Si. Embodiment 8. A composite powder according to any one of Embodiments 1 to 7, wherein the graphitization catalyst or precursor thereof comprises an oxide, carbide, salt, coordination compound, or any combination thereof. Embodiment 9. A composite powder according to any one of Embodiments 1 to 8, wherein the graphitization catalyst or precursor thereof comprises a compound containing boron, iron, nickel, cobalt, molybdenum, titanium, zirconium, manganese, and vanadium. Embodiment 10. The composite powder of Embodiment 9, wherein the boron-containing compound comprises at least one compound selected from the group consisting of boric acid, sodium tetraborate, tetrahydroxyborate, orthoborate, metaborate, triborate, tetraborate, pentaborate, octaborate, boronic acid, boronic acid ester, boron oxide, boron carbide, and combinations thereof.

[0048] Embodiment 11. A composition comprising a graphitization catalyst dispersed in a carbon matrix in an amount of up to about 35% by mass relative to the total mass of the composition, wherein the carbon matrix comprises amorphous carbon. Embodiment 12. The composition of Embodiment 11, manufactured by a process comprising: preparing one composite powder from any one of Embodiments 1 to 10; and heating petroleum pitch in an environment containing about 0.1 mol% or less of oxygen to a carbonization temperature sufficient to form a carbon matrix; and, if present, a graphitization catalyst precursor being converted to a graphitization catalyst during carbon matrix formation. Embodiment 13. The composition of Embodiment 12, wherein the carbonization temperature is in the range of approximately 700°C to approximately 1800°C. Embodiment 14. A method comprising forming a blend containing about 0.1% to about 35% by mass of a graphitization catalyst or its precursor and about 20% to about 99.9% by mass of petroleum pitch, based on the total mass of each blend; and processing the blends under grinding conditions to form a composite powder; wherein the graphitization catalyst is dispersed in a matrix containing petroleum pitch, and the petroleum pitch contains a plurality of pitch particles.

[0049] Embodiment 15. The method of Embodiment 14, wherein forming a blend comprises melt-blending a graphitization catalyst or its precursor and petroleum pitch at a temperature above the softening temperature of the petroleum pitch to disperse the graphitization catalyst or its precursor in a continuous pitch matrix, and processing the blend under grinding conditions comprises grinding the continuous pitch matrix to form pitch particles in which at least a portion of the graphitization catalyst or its precursor is dispersed inside the pitch particles. Embodiment 16. The method of Embodiment 14 or Embodiment 15, wherein the petroleum pitch contains about 50% by mass or more of mesophase pitch. Embodiment 17. Any one of Embodiments 14 to 16, wherein the pitch particles have a particle size in the range of about 1 μm to about 25 μm. Embodiment 18. Any one of Embodiments 14 to 17, wherein the composite powder contains about 0.1% to about 10% by mass of a graphitization catalyst or its precursor. Embodiment 19. Any one of Embodiments 14 to 18, wherein the graphitization catalyst or precursor thereof comprises a compound containing at least one of the following: Group 2 elements, Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, Group 9 elements, Group 10 elements, Group 13 elements, Cu, Zn, or Si. Embodiment 20. Any one of Embodiments 14 to 19, wherein the graphitization catalyst or precursor thereof comprises an oxide, a carbide, a salt, a coordination compound, or any combination thereof.

[0050] Embodiment 21. Any one of Embodiments 14 to 20, wherein the graphitization catalyst or precursor thereof comprises a compound containing boron, iron, nickel, cobalt, molybdenum, titanium, zirconium, manganese, and vanadium. Embodiment 22. The method of Embodiment 21, wherein the boron-containing compound comprises at least one compound selected from the group consisting of boric acid, sodium tetraborate, tetrahydroxyborate, orthoborate, metaborate, triborate, tetraborate, pentaborate, octaborate, boronic acid, boronic acid ester, boron oxide, boron carbide, and any combination thereof. Embodiment 23. Any one of Embodiments 14 to 22, further comprising heating the composite powder in an environment containing about 0.1 mol% to about 20 mol% oxygen at a temperature in the range of about 200°C to about 450°C. Embodiment 24. Any one of Embodiments 14 to 23, further comprising at least partially carbonizing a composite powder in an environment containing about 0.1 mol% or less of oxygen at a carbonization temperature in the range of about 700°C to about 1800°C to at least partially convert petroleum pitch to amorphous carbon.

[0051] Embodiment 25. The method of Embodiment 24, further comprising at least partially carbonizing the composite powder, and then heating it in an environment containing about 0.1 mol% or less of oxygen at a graphitization temperature above the carbonization temperature to convert at least a portion of the amorphous carbon into graphite. Embodiment 26. The method of Embodiment 25, wherein approximately 80% by mass or more of petroleum pitch in the composite powder is converted to graphite. Embodiment 27. The method of Embodiment 25 or Embodiment 26, wherein the graphitization temperature is in the range of approximately 1800°C to approximately 3400°C. Embodiment 28. Any one of Embodiments 25 to 27, wherein heating at the graphitization temperature is performed for approximately 0.1 hours to approximately 5 hours. To facilitate a better understanding of the embodiments of this disclosure, the following examples of preferred or representative embodiments are provided. In no way should the following examples be read as limiting or defining the scope of the invention. [Examples]

[0052] The composite powder sample was prepared by blending raw petroleum pitch with iron (E2), iron oxide (E2), boric acid (E1), ferrocene (E2), titanium carbide (E3), boron carbide (E1), zirconium carbide (E4), manganese (E5), boron (E1), nickel (E6), cobalt (E7), molybdenum (E8), and vanadium (E9) under melt blending conditions in an extruder set to a rotation speed of 280 rpm and a setpoint temperature of over 280°C. The throughput of the resulting melt blend was 300 g / hour. After dispersion of the catalyst into a continuous pitch matrix, the temperature was lowered to room temperature, and the continuous pitch matrix was batch-ground into pitch particles containing boric acid. After obtaining the composite powder, the sample was placed in a furnace and further heated at a temperature of 200°C to 300°C, below the softening point of petroleum pitch, to at least partially react oxygen with petroleum pitch.

[0053] A composite powder containing various graphitization catalysts was first heated in a nitrogen atmosphere at 1100°C for 10 hours to convert the pitch to amorphous carbon, and then heated in an argon atmosphere at 1300-3000°C for 8 hours. The extent of graphitization was determined as a function of the amount of graphitization catalyst packed in the powder, as described below. The extent of graphitization was estimated by powder X-ray diffraction (XRD). The results for each catalyst are summarized in Tables 1, 2, and 3, and Table 1 shows the inter-plane spacing d (d) calculated from powder X-ray diffraction. 002 ) also shows.

[0054] [Table 1]

[0055] As shown in Table 1, the degree of graphitization increased at a catalyst loading of 2 mass% (samples E1-9). The degree of increase in graphitization varied among different catalysts, ranging from 5% to a maximum of 22%. To determine the d spatial values ​​in Table 1, powder XRD patterns were obtained for each sample, and the 002 peak of graphite was further analyzed. Powder XRD was performed using Cu K-α radiation with a wavelength of 1.5406 Å. The 002 peak of graphite is located at a 2θ value of approximately 26°, where θ is the X-ray scattering angle. As an example, Figure 3 shows the powder XRD patterns of the 002 peak of graphite for samples C1, C2, and E1. Based on the 2θ peak position of the 002 peak, the interplane d spatial value (d) was determined using Bragg's equation (Equation 1). 002 ) was calculated. d 002 From the values, the degree of graphitization (G) was calculated using the Mering-Maire equation (Equation 2). The degree of graphitization (G) is further provided in Table 2. In Equations 1 and 2, λ is the X-ray wavelength, and the other variables are defined as above. λ = 2d 002 ×sinθ (Formula 1) G=(0.3440-d 002 / (0.3440-0.3354) (Formula 2)

[0056] The degree of graphitization as a function of temperature, both in and out of the presence of the graphitization catalyst, was also investigated. As shown in Table 2, mesophase pitch and needle coke (samples C1 and C2 in Table 2) yielded similar amounts of graphitization in the absence of a catalyst over temperatures up to 3000°C. In the presence of 2 mass% of the catalyst (samples E1-9 in Table 1), similar amounts of graphitization were achieved, except for lower graphitization temperatures down to 800°C (Figure 4). The rate of graphitization was also enhanced at lower temperatures, with an initial increase in the degree of graphitization observed at approximately 1500°C compared to approximately 1600°C for the non-catalyst samples (C1 and C2). Figure 5 is a graph of capacity retention versus discharge cycles.

[0057] Graphite composite powders containing a graphitization catalyst exhibit smaller crystal size and thickness at the same degree of graphitization as graphite powder produced from a pure carbon source. Furthermore, graphite produced from catalyst-containing carbon shows a lower degree of anisotropy, indicated by a smaller I(10¹) / I(10⁰) peak ratio in the XRD pattern. This property suggests that graphite produced from catalyst samples exhibits a larger surface area and flatter edges despite reaching the same degree of graphitization. Typically, temperatures exceeding 2800°C are required to achieve a degree of graphitization of >90%, which then leads to further growth of the graphite crystals. Maintaining isotropy and small crystal size while exhibiting a high degree of graphitization (>90%) is a unique characteristic of graphite produced from catalyst samples, and the resulting products have novel properties. The unique structure of graphite produced from catalyst samples suggests that it exhibits enhanced conductivity and potentially longer cycle lifetime compared to typical graphite derived from a pure carbon source.

[0058] Next, all graphitized samples were tested in coin cells to determine their specific capacity and initial Coulombic efficiency. This data is summarized in Table 3. Samples with similar degrees of graphitization showed similar initial discharge capacity and initial Coulombic efficiency, suggesting that graphite produced from catalyst samples meets the requirements for battery-grade anode material.

[0059] Three graphitized samples with a degree of graphitization exceeding 90%, two derived from pure carbon precursors and one from a carbon-catalyst precursor, were tested in pouch cells to evaluate the conductivity and rate performance of the samples. The conductivity of these cells was evaluated using charge and discharge mapping protocols. For charge mapping, the cell was charged at a variable rate starting at 0.1C (10 hours) up to 6C (10 minutes), followed by a constant discharge at 0.1C, during which the capacity retention was measured. For discharge mapping, the cell was charged at a fixed rate of 0.1C, followed by a constant voltage step down to 0.05C to achieve 100% charge, and then the discharge rate was varied from 0.1C to 3C (20 minutes). Cycle life was evaluated for charging at a fixed 1C (1 hour) followed by a constant voltage step down to 0.05C, and for discharge at 1C. The results (Tables 4 and 5) show that graphite fabricated from carbon-catalyst precursors exhibits higher capacity retention at both high charge and discharge rates compared to graphite fabricated from current carbon materials. This improved performance suggests that graphite fabricated from catalyst samples differs structurally and compositionally from current samples, resulting in different intercalation and electrochemical mechanisms at the anode. These results are consistent with predictions based on crystal size and anisotropy XRD data for graphite samples.

[0060] [Table 2]

[0061] [Table 3]

[0062] [Table 4]

[0063] [Table 5]

[0064] Table 4 shows the capacity retention as a function of discharge rate. Higher C rates result in faster discharge. In Table 4, 0.1C discharges for 10 hours, 0.2C for 5 hours, 0.5C for 2 hours, 1C for 1 hour, 2C for 30 minutes, and 3C for 20 minutes. Table 5 shows the capacity retention as a function of the charging rate. Higher C rates result in faster charging: 0.1C charges in 10 hours, 0.2C in 5 hours, 0.5C in 2 hours, 1C in 1 hour, 2C in 30 minutes, 3C in 20 minutes, 4C in 15 minutes, 5C in 12 minutes, and 6C in 10 minutes.

[0065] All documents described herein, including any priority documents and / or test procedures, to the extent that they do not conflict with this document, are incorporated herein by reference for the purposes of all jurisdictions where such practice is permitted. As is evident from the general description and specific embodiments above, the forms of this disclosure are exemplary and described, but various modifications can be made without departing from the spirit and scope of this disclosure. Therefore, this disclosure is not intended to be limited thereto. For example, the compositions described herein do not have to include any components or compositions not explicitly listed or disclosed herein. Any methods do not have to include any steps not explicitly listed or described herein. Similarly, the term “comprising” is considered to be synonymous with the term “including.” Whenever a method, composition, element, or group of elements is followed by the transitional phrase “including,” the inventors also intend the same group of compositions or elements followed by the transitional phrases “essentially consisting of,” “consisting of,” “selected from the group consisting of,” or “is,” and vice versa.

[0066] Unless otherwise indicated, all numbers used in this specification and the appended claims to represent quantities, molecular weights, and other properties of components, reaction conditions, etc., shall be understood in all cases to be modified with the term "approximately." Therefore, unless otherwise indicated, the numerical parameters expressed in the following specification and the appended claims are approximations that may vary depending on the desired properties to be obtained by one or more embodiments described herein. Each numerical parameter should be interpreted, at least in light of the reported significant figures, by applying common rounding techniques, not in an attempt to limit the application of the principle of equivalent claims. Wherever a numerical range with lower and upper limits is disclosed, all numbers and all included ranges that fall within that range are specifically disclosed. In particular, all ranges of values ​​disclosed herein (in the form of "about a to about b," or equivalently "approximately a to b," or equivalently "approximately a to b") are to be understood to indicate all numbers and ranges that are encompassed within a broader range of values. Furthermore, terms in the claims have their plain, ordinary meanings unless otherwise explicitly and clearly defined by the patent holder. In addition, the indefinite article "a" or "an," when used in the claims, is defined herein to mean one or more elements that it introduces.

[0067] One or more exemplary embodiments are presented herein. For clarity, not all features of a physical implementation are necessarily described or shown in this application. In developing the physical embodiments of this disclosure, numerous implementation-related decisions, such as compliance with system-related, business-related, government-related, and other constraints, must be made to achieve the developer's objectives, and these will vary from implementation to implementation and from time to time and circumstances. While the developer's efforts may be time-consuming, such efforts will nevertheless be routinely undertaken by those skilled in the art and those interested in this disclosure.

[0068] Accordingly, this disclosure is well adapted to achieve the purposes and benefits mentioned herein, as well as those inherent thereto. The specific embodiments disclosed above are merely examples, and this disclosure can be modified and implemented in different but equivalent ways that will be obvious to those skilled in the art and those who have a benefit of teaching herein. Furthermore, no limitation is intended to the details of the configuration or design shown herein other than those described in the following claims. Accordingly, the specific exemplary embodiments disclosed above may be modified, combined or altered, and it is clear that all such modifications are within the scope and spirit of this disclosure. The embodiments disclosed herein exemplary may preferably be implemented in the absence of any elements not specifically disclosed herein and / or any elements disclosed herein.

Claims

1. A composite powder for electrodes, A graphitization catalyst or its precursor in an amount of approximately 0.1% to approximately 30% by mass relative to the total mass of the composite powder; and Petroleum pitch in an amount of approximately 20% to 99.9% by mass relative to the total mass of the composite powder. A composite powder comprising a graphitization catalyst or its precursor dispersed in a matrix containing petroleum pitch, wherein the petroleum pitch contains multiple pitch particles.

2. The composite powder according to claim 1, wherein the petroleum pitch contains approximately 50% by mass or more of mesophase pitch.

3. The composite powder according to claim 1, wherein a graphitization catalyst or its precursor is dispersed in the interstitial space between pitch particles.

4. The composite powder according to claim 1, wherein at least a portion of the graphitization catalyst or its precursor is dispersed inside the pitch particles.

5. The composite powder according to claim 1, wherein the pitch particles have a particle size in the range of about 1 μm to about 25 μm.

6. The composite powder according to claim 1, comprising approximately 0.1% by mass to approximately 10% by mass of a graphitization catalyst.

7. The composite powder according to claim 1, wherein the graphitization catalyst or precursor thereof comprises a compound containing at least one of the following: group 2 elements, group 4 elements, group 5 elements, group 6 elements, group 7 elements, group 8 elements, group 9 elements, group 10 elements, group 13 elements, Cu, Zn, or Si.

8. The composite powder according to claim 1, wherein the graphitization catalyst or precursor thereof comprises an oxide, a carbide, a salt, a coordination compound, or any combination thereof.

9. The composite powder according to claim 1, wherein the graphitization catalyst or precursor thereof contains a compound containing boron, iron, titanium, zirconium, manganese, nickel, cobalt, molybdenum, and vanadium.

10. The composite powder according to claim 1, wherein the graphitization catalyst comprises a boron-containing compound selected from the group consisting of boric acid, sodium tetraborate, tetrahydroxyborate, orthoborate, metaborate, triborate, tetraborate, pentaborate, octaborate, boronic acid, boronic acid ester, boron oxide, boron carbide, and combinations thereof.

11. A method for forming a composite powder for electrodes, To form a blend containing approximately 0.1% to approximately 35% by mass of a graphitization catalyst or its precursor, and approximately 20% to approximately 99.9% by mass of petroleum pitch, relative to the total mass of each blend; and A method comprising processing a blend under grinding conditions to form a composite powder, wherein a graphitizing catalyst is dispersed in a matrix containing petroleum pitch, and the petroleum pitch contains multiple pitch particles.

12. The method according to claim 11, wherein forming a blend comprises melt-blending a graphitization catalyst or its precursor and petroleum pitch at a temperature above the softening temperature of the petroleum pitch to disperse the graphitization catalyst or its precursor in a continuous pitch matrix, and treating the blend under grinding conditions comprises grinding the continuous pitch matrix to form pitch particles in which at least a portion of the graphitization catalyst or its precursor is dispersed inside the pitch particles.

13. The method according to claim 11, wherein the petroleum pitch contains approximately 50% by mass or more of mesophase pitch.

14. The method according to claim 11, wherein the pitch particles have a particle size in the range of about 1 μm to about 25 μm.

15. The method according to claim 11, wherein the composite powder contains about 0.1% by mass to about 10% by mass of a graphitization catalyst or its precursor.

16. The method according to claim 11, wherein the graphitization catalyst or precursor thereof comprises a compound containing at least one of the following: a group 2 element, a group 4 element, a group 5 element, a group 6 element, a group 7 element, a group 8 element, a group 9 element, a group 10 element, a group 13 element, Cu, Zn, or Si.

17. The method according to claim 11, wherein the graphitization catalyst or precursor thereof comprises an oxide, a carbide, a salt, a coordination compound, or any combination thereof.

18. The method according to claim 11, wherein the graphitization catalyst or precursor thereof comprises a compound containing boron, iron, titanium, zirconium, manganese, nickel, cobalt, molybdenum, and vanadium.

19. The method according to claim 18, wherein the graphitization catalyst comprises a boron-containing compound selected from the group consisting of boric acid, sodium tetraborate, tetrahydroxyborate, orthoborate, metaborate, triborate, tetraborate, pentaborate, octaborate, boronic acid, boronic acid ester, boron oxide, boron carbide, and combinations thereof.

20. The composite powder is heated in an environment containing approximately 0.1 mol% to approximately 20 mol% oxygen at a temperature in the range of approximately 180°C to approximately 450°C. The method according to claim 11, further comprising:

21. The composite powder is at least partially carbonized in an environment containing less than 0.1 mol% oxygen at a carbonization temperature in the range of approximately 700°C to approximately 1800°C to at least partially convert petroleum pitch into amorphous carbon with a maximum degree of graphitization of 60%. The method according to claim 11, further comprising:

22. After carbonizing the composite powder at least partially, it is heated in an environment containing less than approximately 0.1 mol% oxygen at a graphitization temperature above the carbonization temperature to convert at least a portion of the amorphous carbon into graphite. The method according to claim 21, further comprising:

23. The method according to claim 22, wherein approximately 80% by mass or more of petroleum pitch in the composite powder is converted to graphite.

24. The method according to claim 22, wherein the graphitization temperature is in the range of about 1800°C to about 3400°C.

25. The method according to claim 22, wherein heating at the graphitization temperature is performed for approximately 0.1 hours to approximately 8 hours.

26. An electrode material comprising a graphitization catalyst containing a group 13 element dispersed in a carbon matrix at a maximum of approximately 35% by mass relative to the total mass of the electrode material, and which may be coated with amorphous carbon.

27. The electrode material according to claim 26, wherein the carbon matrix has a degree of graphitization of more than 90%.

28. The electrode material according to claim 26, wherein the surface of the electrode material contains nitrides and / or carbides.

29. The electrode material according to claim 26, wherein the graphite crystal size and thickness are up to 70% smaller than those of the raw carbon precursor.

30. A lithium-ion battery comprising the electrode material according to claim 26.

31. The lithium-ion battery according to claim 30, wherein the capacity retention is up to 91% at a 3C discharge rate.

32. The lithium-ion battery according to claim 30, wherein the capacity retention is up to 59% at a 6C charge rate.

33. A method for manufacturing electrode materials, A graphitization catalyst or its precursor in an amount of approximately 0.1% to approximately 30% by mass relative to the total mass of the composite powder; and The present invention provides a composite powder containing approximately 20% to 99.9% by mass of petroleum pitch relative to the total mass of the composite powder, wherein the graphitization catalyst or its precursor is dispersed in a matrix containing petroleum pitch, and the petroleum pitch contains multiple pitch particles; and Heating the composite powder to a carbonization temperature sufficient to form a carbon matrix, wherein the heating is carried out in an environment containing approximately 0.1 mol% or less of oxygen. Includes, A method in which, if present, a graphitization catalyst precursor is converted into a graphitization catalyst during carbon matrix formation.

34. The method according to claim 33, wherein the graphitization temperature is in the range of about 1800°C to about 3400°C.

35. The method according to claim 33, wherein a degree of graphitization of over 90% is achieved at a temperature of 2200°C or higher.

36. The method according to claim 33, wherein a graphitization degree of more than 90% is achieved within 0.1 hours.

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