Producing graphitic particles from petroleum pitch with stabilization above softening point

Abstract

A variety of methods and systems for processing petroleum precursor to form graphitic particles which may be suitable for use as negative electrode materials in batteries with stabilization performed at or above the softening point of the petroleum precursor are disclosed. In embodiments, the method of fabricating a negative electrode includes grinding a petroleum precursor at a temperature below a softening point of the petroleum precursor to form at least precursor particles, carbonizing the precursor particles by heating to a temperature from about 700 °C to about 1800 °C to form at least carbonized particles, and graphitizing by heating to a graphitization temperature of about 2000 °C to about 4000 °C.

Description

PRODUCING GRAPHITIC PARTICLES FROM PETROLEUM PITCH WITH STABILIZATION ABOVE SOFTENING POINT CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the priority of U.S. Provisional Patent Application No. 63 / 695,592, filed September 17, 2024, which is incorporated by reference in its entirety. FIELD

[0002] The present disclosure relates to processing of petroleum pitch to produce graphitic particles, and, more particularly, to processing of petroleum pitch to form graphitic particles which may be suitable for use as negative electrode materials with stabilization performed at or above the softening point of the petroleum pitch. BACKGROUND

[0003] Lithium-ion battery is a rechargeable battery that stores and discharges energy by the motion or movement of lithium ions between two electrodes with opposite polarity called the cathode and the negative electrode through an electrolyte. This continuous movement of lithium ions from the negative electrode to the cathode and vice versa is critical to the function of a lithium-ion battery. The negative electrode, also known as the negatively charged electrode, discharges lithium ions into the electrolyte. The negative electrode has a remarkable effect on the overall performance of the whole battery based on its properties and morphology. Synthetic Graphite is now used primarily in commercial lithium-ion battery negative electrodes due to its advantageous properties such as widespread availability, outstanding electronic conductivity, low cost, and a favorable hierarchical arrangement for Li-ion insertion. There are two distinct variants of graphite material for battery negative electrode material: synthetic graphite and natural graphite. Synthetic graphite has a higher density and thermal conductivity than natural graphite.

[0004] However, synthetic graphite negative electrodes have some drawbacks including low charging rate as well as safety risks, which prompted further research into the performance optimization of carbon-based material negative electrodes. The low reduction voltage (~0.2 V vs. Li / Li+) of graphite in current negative electrode is close to the reduction voltage of lithium metal so that negligible volume change occurs during intercalation / deintercalation of lithium ions, yielding an excellent cyclability. Once lithium ions embed into graphite, the interstice between two adjoining layers of carbon atoms offers insertion sites for the lithium ions, thereby preventing the negative electrode material's shape, size, and structure from changing during thecharge-discharge process. As the pathway of lithium ions is limited by these interstices, the charge / discharge efficiency at high rates is low, and the power density is insufficient for the latest batteries. The rate performance of graphite negative electrode materials may be improved by graphite spheronization, surface doping, and / or carbon coating.

[0005] The spheronization process decreases the surface area to allow more graphite into a smaller volume. This creates a smaller, denser, and more efficient negative electrode product for the battery. Natural graphite's inherent anisotropy—distinct properties along different crystallographic axes—is mitigated through graphite spheronization. These optimizations result in consistent electrochemical performance across diverse orientations.

[0006] Current methods for improving fast-charging graphite anode materials in lithium- ion batteries typically involve either forming secondary particle structures through graphitization or modifying primary particle structures via surface treatments. Secondary structures can ensure high capacity when using easily graphitized materials, but they suffer from poor fast-charging performance due to highly ordered surfaces. In contrast, primary structures with surface modification can reduce interface impedance and improve charging speed, but they often lack sufficient capacity and have longer diffusion paths that hinder performance.

[0007] Several patents have explored different combinations of raw materials and processing techniques, but none have successfully balanced both high capacity and fast- charging capability. Common issues include poor material selection, overly ordered surfaces post-graphitization, and structural limitations that restrict ion diffusion. As a result, existing technologies have not yet achieved industrially viable solutions that meet both performance criteria simultaneously.

[0008] Secondary particle graphite is produced through a process called secondary granulation, which enhances the performance of graphite anodes in lithium-ion batteries. The process begins by pulverizing carbon-based raw material (often coal-based needle coke) into small particles. These particles are then mixed with a binder, typically coal tar pitch, and granulated in a reaction kettle to form larger composite particles. After granulation, the material undergoes high-temperature graphitization to achieve the desired crystalline structure. This method combines the benefits of small particles (high surface area and fast lithium-ion migration) with those of large particles (high compaction density and capacity), resulting in an anode material that balances capacity and fast-charging performance.

[0009] Compared to single-particle graphite, secondary particle graphite offers improved rate capability, better low-temperature performance, and higher first Coulombic efficiency.The granulated structure increases the number of lithium-ion intercalation channels and enhances isotropy, which helps reduce internal resistance and improve electrochemical performance. However, the increased surface area can slightly reduce high-temperature stability. Overall, secondary particle graphite is considered superior for high-performance lithium-ion batteries, especially in applications requiring fast charging and long cycle life. SUMMARY

[0010] In one or more aspects, the present disclosure provides methods of fabricating a negative electrode comprising grinding a petroleum pitch at a temperature below a softening point of the petroleum pitch to form at least pitch particles; stabilizing the pitch particles by heating to a stabilizing temperature from about 100 ^C to about 400 ^C, carbonizing the pitch particles by heating to a temperature from about 700 ^C to about 1800 ^C to form at least calcined particles, and graphitizing by heating to a graphitization temperature of about 2000 ^C to about 4000 ^C to form at least graphitized particles.

[0011] In some or other aspects, a composition for negative electrodes comprises secondary graphitic particles in an amount from about 2 % to about 100%; wherein the secondary graphitic particles have a degree of graphitization of about 80% or more and a specific surface area of about 0.1 m2 / g to about 6 m2 / g; wherein the secondary graphitic particles comprise microparticle active material produced at least one from at least one carbon source selected from the group consisting of mesophase pitch, needle coke, petroleum coke, and any combination thereof; and wherein the secondary graphitic particles are granulated using at least one binder, wherein the at least one binder is selected from the group of binders consisting of pitch, asphalt, phenolic resin, furfural resin, epoxy resin, lignin, starch, and any combination thereof.

[0012] These and other features and attributes of the disclosed compositions and methods of the present disclosure and their advantageous applications and / or uses will be apparent from the detailed description which follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] To assist one of ordinary skill in the relevant art in making and using the subject matter thereof, reference is made to the appended drawing. The following figure is included to illustrate certain aspects of the disclosure and should not be viewed as an exclusive configuration. 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.

[0014] The FIGURE is a block diagram of an illustrative system and method for processing petroleum pitch according to the present disclosure.DETAILED DESCRIPTION

[0015] The present disclosure relates to a graphite negative electrode for lithium-ion battery prepared from a petroleum precursor with particle size Dv50 from 1 micrometer to 25 micrometers, wherein the petroleum precursor comprises a benzene soluble fraction comprising a hexane-insoluble (HI) sub-fraction of at least 20 wt % of the benzene soluble (BS) fraction (HI in BS > 20 wt %). The petroleum precursor may comprise hydrocarbon fractions with boiling point above 200 °C (ASTM D7500 >350 °C, >450 °C). Upon heating, these hydrocarbon fractions may produce a thin layer of pitch like material that increase particle size without the need for an additional binder. This agglomeration behavior and surface coating layer produced by this hydrocarbon fluid produces graphite with excellent electronic properties.

[0016] The petroleum precursor may exhibit agglomeration tendency when heated to temperatures from 200 °C to 900 °C, from 300 °C to 800 °C, from 450 °C to 800 °C, from 450 °C to 750 °C, or any value in between. The agglomeration tendency may be defined as Dv50 (after heat treatment) / Dv50 (milled) > 1.1 (preferred ranges >1.2 more preferred >1.5 and more preferred is 1.4 to 3.0).

[0017] The present disclosure further relates to a graphite negative electrode for lithium- ion battery prepared from a petroleum precursor with particle size Dv50 from 1 micrometer to 25 micrometers with volatile matter content of 1 wt % or more, from 5 wt % to 90 wt %, from 8 wt % to 50 wt %, from 10 wt % to 35 wt %, or from 5 wt % to 20 wt % as measured by ASTM D6374; for example.

[0018] The petroleum precursor may have a ratio of benzene soluble to benzene insoluble above 0.25 (BS / BI > 0.25), above 0.40, above 0.60, or any value in between, quinoline soluble to quinoline insoluble above 0.10 (QS / QI > 0.10), above 0.25, above 0.40, or any value in between, and a hexane-insoluble (HI) sub-fraction of at least 20 wt % of the benzene soluble (BS) fraction (HI in BS > 20 wt %), HI in BS > 30 wt %; HI in BS > 65 wt %, HI in BS > 80 wt %, and a ratio of hexane insoluble to benzene soluble of less than 3, less than 2 (HI / BS<2.0), or from 0.001 to 1.5, for example. Further, the benzene soluble combined with the quinoline soluble represent at least 15 wt % of the organics, at least 25 wt % of the organics, at least 35 wt % of the organics; at least 50 wt % of the organics, r any value in between, for example.

[0019] The present disclosure relates to processing of a petroleum precursor to produce graphitic particles, to form graphitic particles which may be suitable for use as negative electrode material by: 1) pulverizing the green coke materials and classifying them to remove fine powder to obtain a Dv50 of 1 micrometer to 25 micrometers precursor; 2) shaping theprecursor from step 1 to increase the roundness as measured by tap density with preferred tap density >0.8 g / cm33); 3) subjecting the step 3 material to controlled heat treatment (HT) without any added binder by heating up to 1000 °C, from 500 °C to 900 °C, or from 600 °C to 900 °C in an inert atmosphere of Argon or Nitrogen to obtain a powder meeting the criteria D50 (HT) / D50 >1.1 (preferred ranges as above). The heating rate of the temperature increase may be from 20 °C / hour to 150 °C / hour or from 60 °C / hour to 120 °C / hour; 4) subjecting the product obtained in step 3) to a graphitization treatment at a temperature from 2800 °C to 3200 °C to obtain artificial graphite.

[0020] The petroleum precursor may be a petroleum coke, delayed coke, sponge coke, shot coke, calcined coke, or any combination thereof. The petroleum precursor may be a petroleum pitch. The petroleum precursor may further comprise additives such as graphitization catalyst such as Boron, Chromium, Vanadium, Cerium, Cesium, Silicon, Titanium incorporated in the melt state. The petroleum pitch comprises fines (i.e. Dv50 < 25 micrometers) selected from petroleum coke, pitch coke, shot coke, delayed coke, sponge coke, calcined coke, calcined sponge coke, biochar, gas pyrolysis carbon, flake natural graphite, graphite fines, or any combination thereof incorporated in the melt state. The petroleum precursor may be a blend that has combined volatile matter meeting ranges described above.

[0021] The present disclosure relates to processing of petroleum pitch to produce graphitic particles, and, more particularly, to processing of petroleum pitch to form graphitic particles which may be suitable for use as negative electrode materials with stabilization or infusibility treatment performed at or above the softening point of the petroleum pitch. As used herein, graphitic particles refer to particles having 80 % or more degree of graphitization. Further, a degree of graphitization greater than 90 % is typically suitable for negative electrode. The degree of graphitization is determined using the d002 peak from a diffraction pattern acquired using X-Ray Diffraction (XRD).

[0022] In embodiments, the petroleum pitch precursor is subjected to an optional stabilization or infusibility treatment after the step 1 described above (the pulverization step) comprising heating the material in a rotary kiln or fluidized bed furnace from 150 °C to 350 °C in an oxygen containing environment for up to 6 hours, from 10 minutes (min.) to 5 hours, from 30 min to 4 hours, from 1 hour to 2 hours, for example. In some embodiments, an optional binder may be added in step 3 described above (the heating treatment step). The binder may be any pitch including petroleum-based pitch, coal tar-based pitch, phenolic or furan resins, polymers including PVA, CMC, or SBR, natural binders such as lignin, starch, or molasses, for example, or any combination thereof.

[0023] Advantageously, by adjusting the heat treatment conditions during stabilization, graphitic particles may be produced from the petroleum pitch with reduction or elimination of the need for binders or additives for agglomeration. In some embodiments, the binder may be a thermally and chemically untreated petroleum pitch or mesophase pitch or isotropic pitch. Coke Description and Coke Fines

[0024] As used herein, the term “delayed coke,” including its grammatical variants, refers to the solid carbonaceous byproduct formed in a delayed coking process, irrespective of its morphology. This includes, but is not limited to, shot coke, sponge coke, transition coke, and needle coke. The delayed coking process involves thermally cracking residual oil feed by heating it to a predetermined temperature within one or more coker drums. This process converts heavy hydrocarbon chains into a vapor-phase product stream and a concentrated solid carbon residue. The term “delayed” reflects the residence time of the feedstock within the reactor during the cracking reaction.

[0025] Delayed coke may be characterized by a sulfur content ranging from approximately 1 wt.% to 8 wt.%, volatile matter content between approximately 8 wt.% and 15 wt.%, a Hardgrove Grindability Index (HGI) ranging from about 30 to 130, and a bulk density in the range of approximately 1.2 to 1.4 g / cm³.

[0026] Delayed coking typically yields three primary types of solid coke products, each with distinct properties and commercial value: needle coke, sponge coke, and shot coke.

[0027] Needle coke represents the highest quality among these varieties. Upon further thermal treatment, needle coke exhibits high electrical conductivity and a low coefficient of thermal expansion, making it suitable for use in electric arc furnace electrodes. It is generally low in sulfur and metallic impurities and is commonly derived from aromatic-rich feedstocks such as slurry oils, decant oils from catalytic cracking units, and thermal cracking tars. Needle coke is typically not produced from residuum-based feedstocks via delayed coking.

[0028] Sponge coke, which is considered a lower-grade product, is commonly produced in refinery operations using feedstocks rich in asphaltenes, heteroatoms, and metals. When sulfur and metal contents are sufficiently low, sponge coke may be used in the production of aluminum smelting electrodes. Otherwise, it is utilized as a fuel source. The term “sponge coke” refers to its porous, sponge-like texture. Conventional delayed coking of residuum feedstocks generally yields sponge coke.

[0029] Shot coke is regarded as the lowest quality form of delayed coke. It is named for its spherical, pellet-like shape, typically ranging from 1 / 16 inch (1.6 mm) to 3 / 8 inch (9.5 mm) in diameter. Shot coke tends to agglomerate, especially when mixed with sponge coke, forminglarge masses that may exceed one foot in diameter, potentially causing operational issues in refinery equipment. It is typically produced from low-quality, resin- and asphaltene-rich feedstocks and is primarily used as a high-sulfur fuel in applications such as cement kilns and steel manufacturing.

[0030] Transition coke refers to a form of delayed coke exhibiting intermediate morphology between sponge coke and shot coke. For example, it may possess a predominantly sponge-like structure with emerging discrete shot-like spheres.

[0031] As used herein, the term “carbon-to-hydrogen ratio” or “C / H ratio,” including its grammatical variants, refers to the proportion of elemental carbon to elemental hydrogen in a petroleum-based composition. This ratio is determined in accordance with ASTM D5373-21, “Standard Test Methods for Determination of Carbon, Hydrogen and Nitrogen in Analysis Samples of Coal and Coke.”

[0032] As used herein, the term “thermogravimetric analysis” or “TGA,” and its grammatical variants, refers to the measurement of sample weight loss as a function of temperature (°C), which is indicative of the percentage of degradable components present in the sample. Solvent Extraction

[0033] Hexane extraction fraction is the portion of the petroleum precursor that is soluble / insoluble in n-hexane when tested in accordance with ASTM D2007 or an equivalent method. The hexane soluble fraction comprises predominantly lower molecular weight hydrocarbons, residual oils, and asphaltene precursor. The hexane insoluble fractions include highly condensed aromatic hydrocarbons.

[0034] Benzene extraction fraction is the portion of the petroleum precursor that is soluble / insoluble in benzene when tested in accordance with ASTM D2318 or an equivalent method. The benzene soluble fraction comprises predominantly polynuclear aromatic hydrocarbons, resins and other solvent extractables organic materials of intermediate to high molecular weight. Benzene insoluble fraction comprises highly condensed, cross-linked aromatic carbon to aromatic species and coke.

[0035] Quinoline extraction fraction is the portion of the petroleum precursor when tested in accordance with ASTM D2319 or equivalent method. The quinoline soluble fraction includes large, complex aromatic molecules such as mesophase pitch. The quinoline insoluble fraction includes the refractory part of coke.

[0036] Hexane insoluble of Benzene soluble (HI_in_BS): the mass percentage of material that is hexane insoluble within the benzene soluble fraction when the BS extract is contacted with n-hexane under standardized conditions.

[0037] Higher BS / BI (Benzene insoluble) ratio is an indicator of more fusible aromatic phase relative to rigid carbon matrix which increases agglomeration potential.

[0038] High QS / QI ratio is an indicator of mesophase precursors relative to non-fusible domains.

[0039] High HI_in_BS % greater asphaltene like content in the fusible pool strongly promotes fusion. Petroleum Pitch

[0040] Petroleum pitch (also referred to herein as “pitch”) is a carbon source of the residue obtained from the heat treatment and distillation of petroleum fractions or coal tar. It is solid at room temperature, comprising a complex mixture of numerous predominantly aromatic hydrocarbons and exhibiting a broad range of softening temperatures instead of a defined melting temperature. Petroleum pitch may have a temperature softening point between 100 °C and 500 °C depending upon its carbon content (e.g., from 80 wt% to 90 wt%) and its molecular weight. As used herein, the “softening point” or “softening temperature” of petroleum pitch refers to the point at which the pitch will flow under a given load on heating. The softening point depends on a number of factors, including average molecular weight and intrinsic viscosity. The softening point is determined in accordance with ASTP D36 / D36M using a ring- and-ball apparatus.

[0041] Petroleum pitch is liquid at high temperatures and may easily be removed from the equipment as compared to coke. The raw materials in petroleum pitch may be petrochemical byproducts such as pyrolysis fuel oil, fluid catalytic cracking-decant oil, and vacuum residue, which are cost-effective, abundant, and high in carbon content with an aromatic structure. While the yield of petroleum pitch from most crude oils may be relatively low, the large crude oil runs in refineries can result in the production of large amounts of petroleum pitch.

[0042] The highly ordered crystalline structure of pitch makes it a suitable precursor for making graphitic particles with high electric and thermal conductivity. These pitch-derived graphitic particles may also have high strength through traditional heat treatment processes (e.g., carbonation and graphitization). However, petroleum pitch becomes deformable at its softening temperature which may lead to some difficulty in using petroleum pitch as a precursor to amorphous carbon and graphite for negative electrode material. Namely, a shaped pitch material, such as pitch particles in a mold, may deform prior to undergoing carbonizationor graphitization, which may be unsuitable for producing objects having strict size or shape tolerances such as a negative electrode for a lithium-ion battery. Since there may be a large difference between the softening temperature and the temperature at which carbonization takes place, there is often a wide temperature window over which deformation of the pitch particles may occur. Example Petroleum Pitch

[0043] Petroleum pitch may be produced as a byproduct of thermal or catalytic conversion of a hydrocarbon feedstock (e.g., a highly aromatic hydrocarbon feedstock) or recovered from a source material, such as petroleum. The petroleum pitch used in the present disclosure may be obtained from any source or process, provided that the petroleum pitch does not contain components that might be detrimental to an intended application following carbonization or graphitization of the pitch particles. Example feedstocks for petroleum pitch may include main column bottoms, ethylene cracker bottoms, or other highly aromatic oils, coil tar, and derivatives of petroleum and coal tar. The petroleum pitch may be produced from a hydrocarbon feedstock, including virgin naphtha, coker naphtha, steam cracked naphtha, catalytically cracked naphtha, gas oil, steam cracked gas oil, coker gas oil, catalytically cracked gas oil, steam cracked tar, vacuum gas oil, heavy coker gas oil, raffinate reformate, Fischer- Tropsch liquids, Fischer-Tropsch gases, natural gasoline, distillate, heating oil, jet fuel, diesel, kerosene, gasoline, atmospheric pipestill bottoms, vacuum pipestill streams including bottoms, wide boiling range naphtha to gas oil condensates, heavy non-virgin hydrocarbon streams from refineries, waxy residues, atmospheric residues, residue admixtures, crude oil, and any combination thereof.

[0044] The petroleum pitch may be isotropic pitch or mesophase pitch. Petroleum pitch comprises a complex mixture of aromatic molecules that may be at least partially ordered and coalesced into a liquid crystalline phase. The liquid crystalline phase may be referred to as “mesophase pitch,” which may comprise a majority or all of a petroleum pitch in some cases. In some examples, the mesophase pitch may be formed, for example, by thermal conversion of isotropic pitch in an open or closed system. The pitch may have a mesophase content of from 0 wt % to 100 wt %. In some examples, at least a majority of the petroleum pitch may comprise a mesophase pitch. Once carbonized and converted to graphitic particles, the highly aligned structure of mesophase pitch may promote enhanced electrical conductivity of the graphite, about 50 wt% or greater, or about 60 wt% or greater, or about 70 wt% or greater, or about 80 wt% or greater, or about 90 wt% or greater, or about 95 wt% or greater, or about 99 wt% or greater, or about 99.9 wt% or greater, such as about 80 wt% to about 99.9 wt%, or about 90wt% to about 99.9 wt%, or about 95 wt% to about 99.9 wt%, or even 100 wt%, each based on a total mass of the petroleum pitch. However, petroleum pitch with less than a majority of mesophase pitch may also be used in accordance with example embodiments. For example, the petroleum pitch used herein may have a mesophase pitch content of less than 5 wt%. The mesophase content may be measured using polarized light microscopy.

[0045] Prior to undergoing stabilization through heating of the pitch particles, the petroleum pitch being processed according to the disclosure herein may have a softening point of 500 °C or below, or 450 °C or below, or 400 °C or below, or 350 °C or below, or 300 °C or below, or 150 °C or below, or 100 °C or above. In non-limiting examples, the softening point of the petroleum pitch may reside within a range of about 180 °C to about 500 °C, or about 250 °C to about 500 °C, about 250 °C to about 400 °C, or about 280 °C to about 400 °C, or about 180 °C to about 400 °C, or about 250 °C to about 330 °C, or about 300 °C to about 340 °C. As used herein, “glass transition temperature” (Tg) refers to a temperature or a range of temperature at which a material (e.g., a polymer substrate) changes from a rigid glassy material to a soft material. The Tgand the change in the heat capacity can be measured using the differential scanning calorimeter (DSC) technique. Tg refers to a mid-point of the temperature at which a change in heat capacity is recorded on the second heating scan of a DSC experiment at 10 °C. / min heating and cooling rate. For purposes of the disclosure herein, Tg may be measured using, for example, thermal analysis TA INSTRUMENTS DISCOVERY DSC or TA INSTRUMENTS Q2000™, as indicated.

[0046] In some embodiments, the pitch has a carbon residue content of from 20 wt % to 99 wt %, such as from 30 wt % to 99 wt %, such as from 40 wt % to 99 wt %, such as from 50 wt % to 99 wt %, such as from 50 wt % to 95 wt %, such as from 50 wt % to 90 wt %, such as from 50 wt % to 85 wt %, and such as from 50 wt % to 80 wt %, based on the total weight of the pitch composition. As used herein, carbon residue is determined in accordance with ASTM D4350-15 standard test method.

[0047] In some embodiments, the pitch has a volatiles content of 1 wt % or less (or 0.9 wt % or less, or 0.8 wt % or less, or 0.7 wt % or less, or 0.6 wt % or less, or 0.5 wt % or less, or 0.4 wt % or less, or 0.3 wt % or less, or 0.2 wt % or less, or 0.1 wt % or less), based on the total weight of the pitch, at spinning temperature. As used herein, the term “volatile” refers to a substance that is readily vaporizable at the respective temperature and can include light products produced during cracking reactions. The term volatile can be applied to liquids and solids. For example, some solid materials can change directly from solid to vapor without ever becoming liquid, via a process called sublimation.

[0048] In some embodiments, the pitch has a nitrogen content of from 0 wt % to 3 wt % (or from 0 wt % to 2 wt %, or from 0 wt % to 1 wt %, or from 0.1 wt % to 2 wt %, or from 0.1 wt % to 1.9 wt %, or from 0.1 wt % to 1.8 wt %).

[0049] In some embodiments, the pitch has a sulfur content of from 0 wt % to 10 wt % (or from 0 wt % to 9 wt %, or from 0 wt % to 8 wt %, or from 0 wt % to 7 wt %, or from 0 wt % to 6 wt %, or from 0 wt % to 5 wt %, or from 0 wt % to 4 wt %, or from 0 wt % to 3 wt %, or from 0 wt % to 2 wt %, or from 0 wt % to 1 wt %, or from 0.1 wt % to 0.7 wt %).

[0050] In some embodiments, the pitch has a density from about 0.90 g / cc to about 1.5 g / cc, from about 1.0 g / cc to about 1.25 g / cc, from about 1.0 g / cc to about 1.2 g / cc, from about 1.0 g / cc to about 1.15 g / cc, or from about 1.05 g / cc to about 1.14 g / cc.

[0051] In some embodiments, the amount of carbon residue formed after evaporation and pyrolysis of the pitch ranges from about 70 % to about 99 %, from about 75 % to about 98 %, from about 80 % to about 95 %, or from about 85 % to about 90 % using a Micro Carbon Residue Tester (MCRT).

[0052] While the application generally describes the use of petroleum pitch as the feed, example embodiments may use other carbons sources, including raw coke materials, such as one or more of raw petroleum coke, raw asphalt coke, or metallurgical coke, for example. In some examples, the raw coke material includes raw petroleum coke. In some embodiments, the raw coke material includes needle coke, sponge coke, and shot coke. The needle coke may include one or more needle raw petroleum coke and needle raw coal tar coke. In some examples, the needle coke includes needle petroleum. Example Graphitic Particle Production from Petroleum Precursor

[0053] Example embodiments may adjust the heat treatment conditions of the petroleum pitch to provide graphitic particles, which may be suitable for use as negative electrode materials. For example, a process for forming graphitic particles may include grinding the petroleum pitch at a temperature below a softening point of the petroleum pitch to form at least pitch particles, stabilizing the pitch particles by heating to a stabilizing temperature from about 100 ^C to about 400 ^C, carbonizing the pitch particles by heating to a temperature from about 700 ^C to about 1800 ^C to form at least calcined particles, and graphitizing by heating to a graphitization temperature of about 2000 ^C to about 4000 ^C to form at least graphitized particles.

[0054] In embodiments, methods and systems may stabilize the pitch at temperatures above its softening point. In contrast, traditional stabilization of the pitch particles has typically been performed at temperatures below the softening point. With stabilization performed at elevatedtemperatures, agglomeration of intermediate pitch particles may be achieved in the stabilization stage without the need for additional binders or additives to agglomerate in a granulating step. STEP 1: Grinding or Pulverization Step:

[0055] The grinding step may be performed in a grinding apparatus to produce a plurality of petroleum precursor particles. To facilitate the production of precursor particles, the petroleum pitch or petroleum coke may be maintained at a temperature below the softening temperature in the grinding apparatus. By keeping the petroleum pitch below the softening temperature, the pitch particles remain brittle, and glass-like which makes it easier for grinding. Moreover, the pitch particles can retain their shape and form after grinding when temperatures remain below the softening point.

[0056] A method and apparatus known in the art may be employed to comminute green coke material, including but not limited to jet mills, mechanical mills, or roller mills. The crushing process typically results in a particle size distribution containing an excess of fine particles and, in some cases, oversized particles. Accordingly, a classification step may be performed after crushing to remove particles that fall outside the desired size range. This classification enables the production of a precursor material with an optimized particle size distribution, which is advantageous for subsequent shaping and granulation / heat treatment processes. The classification may be carried out using conventional equipment and techniques, such as classification screens, gravity classifiers, centrifugal classifiers, or equivalent systems. Optionally, <10% of natural graphite or graphite fines or petcoke fines can be added in this co- milling step.

[0057] Grinding may be utilized to facilitate preparation of said pitch particles herein. Any suitable grinding apparatus or technique may be used to facilitate production of pitch particles through pulverization of a petroleum pitch sample. The terms “grinding” and “pulverizing,” as well as grammatical variants thereof, are to be considered equivalent herein. Suitable grinding processes may employ a grinding apparatus that may be operated in a batchwise manner or a continuous manner. Batchwise grinding apparatuses may employ, for example, ball milling and like techniques. Continuous grinding apparatuses may employ, for example, jet milling, impact milling, roller milling, Wiley milling, extrusion, and related techniques. In particular examples, grinding in the disclosure herein may be performed by jet milling. Jet milling may be especially desirable since it typically produces narrow particle size distributions. Moreover, because jet milling equipment lacks blades and other direct contact grinding structures, there is a lower likelihood of introducing contaminants from the mill (e.g., due to micro abrasion of the milling equipment) compared to other types of grinding processes.

[0058] In some embodiments, two or more grinding apparatuses may be used in combination with one another in implementing the embodiments of the present disclosure. For example, two or more jet mills or extruders in series may be utilized to achieve a desired particle size and / or two or more jet mills or extruders in parallel may be utilized to increase throughput.

[0059] Grinding of the petroleum pitch may produce pitch particles and petroleum pitch fines. Petroleum pitch fines may include pitch particles having a particle size of about 5 microns or below or about 1 micron or below, including pitch fines having a size residing in a nanoparticle size range of about 500 nm or below or about 100 nm or below. Pitch particles may have a size ranging from about 1 micron to about 100 microns, or about 1 micron to about 50 microns, or about 5 microns to about 100 microns, or about 5 microns to about 50 microns, or about 5 microns to about 25 microns, or about 1 micron to about 25 microns, or about 10 microns to about 30 microns, or about 15 microns to about 50 microns. The pitch particle size is determined using the diffraction pattern of particles upon shining a laser on it. This correlation is based on the Mie theory of light scattering. The experiments are run on a Malvern Panalytical Mastersizer 3000. The ratio of pitch fines to pitch particles may range from about 1:1 to about 1:9, or about 1:1 to about 1:99, or about 1:3 to about 1:9 on a mass basis. Alternately, pitch fines may be produced in preference to pitch particles in the grinding process in a ratio ranging from about 9:1 to about 1:1, or about 8:1 to about 1:1, or about 7:1 to about 1:1, or about 6:1 to about 1:1. Desirably, the pitch fines that are produced may be recovered and re-processed into pitch particles having a desired size range according to the disclosure herein.

[0060] In addition, pitch particles that are not within a desired size range may be rejected by a size separation, such as sieving, and the rejected pitch particles may be recycled in a similar manner to the pitch fines, preferably with the rejected pitch particles being combined with the pitch fines to form the pitch melt. Accordingly, the present disclosure may facilitate a tight sizing (narrow particle size distribution) of the pitch particles but without suffering from excessive mass loss of the petroleum pitch sample in doing so. Shaping step:

[0061] The edges and corners of the granular precursor material are smoothed through a shaping process to enhance the stability of the secondary particles formed during subsequent granulation and heat treatment. The shaping treatment may be performed using equipment and techniques known in the art, such as shaping machines or equivalent apparatus. Following shaping, a fine powder removal step may be conducted to refine the particle size distribution.This step enables adjustment of the D₁₀ value of the shaped particle product to fall within a desired range, thereby ensuring that the D₁₀ of the resulting artificial graphite meets specified performance criteria. In certain embodiments, the D₁₀ of the shaped particles is controlled to be at least 0.5 micrometer (μm), from 0.5 μm to 1.5 μm, for example. Optionally, less than 10 % of natural graphite or graphite fines or petcoke fines can be added in this co-shaping step. Stabilizing Step (optional step):

[0062] After grinding, the pitch particle may be stabilized by a heat treatment to promote at least partial crosslinking in accordance with example embodiments. In contrast to conventional techniques, example methods may include stabilizing the pitch particles at a higher temperature above the softening temperature of the pitch particles such as from 100 °C to 500 °C, from 180 °C to 400 °C, for example. The stabilization step may be performed under air flow with oxygen representing about 10 % of the environment or under oxygen flow or without any oxygen such as under nitrogen flow, for example. A variety of factors affect the stabilization of the petroleum pitch including the nature of the petroleum pitch (e.g., its carbon content and molecular weight), the gaseous environment, the temperature ramping rate, and the time maintained at temperature.

[0063] The temperature ramping rate and the holding temperature, the temperature at which heating is maintained, depend upon the softening temperature and the targeted size of the petroleum pitch particles. In some embodiments, the temperature ramping rate is maximal while the time at which the heating temperature is maintained is minimized to obtain petroleum particle size in between 1 µm to 100 µm, or from 10 µm to 25 µm, for example. For example, the temperature ramping rate may be from about 0.5 ^C per minute to about 20 ^C per minute, from about 10 °C to about 20 °C per minute, from about 12 °C to about 18 °C, or from about 14 °C about 16 °C, or 15 °C per minutes. In embodiments, the stabilization step may include heating the pitch particle at 0.5 °C per minute up to from about 180 °C to about 250 °C in air. Then, the heat may be maintained at 180 °C or 250 °C for 2 hours in air, for example.

[0064] As discussed in brief above, the procedure of stabilization may facilitate stabilization of the petroleum pitch of the pitch particles by promoting at least partial crosslinking thereof. In non-limiting examples, the stabilization temperature may be at least 5 °C above the softening temperature, or at least 10 °C above the softening temperature, or at least 15 °C above the softening temperature, or at least 20 °C above the softening temperature, or at least 25 °C above first softening temperature, or at least 50 °C above the softening temperature, or at least 75 °C above the softening temperature, or at least 100 °C above the softening temperature, or at least 150 °C below the first softening temperature, such as withina range of about 180 °C to about 500 °C, or about 200 °C to about 250 °C, or about 250 °C to about 300 °C, or about 200 °C to about 300 °C, or about 350 °C to about 450 °C. The temperature of the petroleum pitch may be maintained at this stabilization temperature over a period of about 10 minutes to about 24 hours, or about 10 minutes to about 6 hours, or about 30 minutes to about 20 hours, or about 30 minutes to 6 hours, or about 1 hour to about 18 hours, or about 30 minutes to about 2 hours, or about 2 hours to about 6 hours.

[0065] The treatment temperature of the pitch particles may correspond to an onset of oxidation temperature (OOT) associated with the petroleum pitch. The onset of oxidation temperature may be characterized by a rapid exothermic release of heat upon reaction of the petroleum pitch with oxygen. Maintaining the treatment temperature at the onset of oxidation temperature for a specified hold time may be desirable for promoting stabilization of the petroleum pitch.

[0066] The at least partial crosslinking occurring at the treatment temperature may increase the softening temperature of the petroleum pitch from its original softening temperature prior to heat treatment during stabilization to a second softening temperature that is higher than the first softening temperature, which may encourage the petroleum pitch to maintain its shape upon being further heated during carbonization or graphitization. In non-limiting examples, the softening temperature may increase due to the stabilization treatment by at least 5 °C, at least 10 °C, at least 20 °C, at least 30 °C, at least 40 °C, or at least 50 °C or higher. Granulation / Agglomeration / Heat Treatment Step:

[0067] The resulting pulverized and shaped product is then subjected to a controlled heat treatment process from 200 °C to 1000 °C, from 300 °C to 950 °C, from 400 °C to 900 °C, for example, wherein independently dispersed primary particles of 1 micrometer to 25 micrometers are aggregated to form secondary particles where the Dv50 (HT) / Dv50(milled)> 1.1. This aggregation enhances the isotropy of the resulting artificial graphite, thereby contributing to a reduction in the orientation index (OI) of the negative electrode plate. The controlled heat treatment process may be performed without the addition of a binder. Preferably, no binder is added, particularly when the volatile content of the petroleum precursor material is at least 2%. When a binder is used, its amount is controlled to not exceed 5% of the total weight of the petroleum precursor. Binder addition within this range can improve the gram capacity and structural integrity of the artificial graphite. The binder is preferably selected from pitch, furfural, starch, phenolic resin and asphalt. Excessive volatile content in the petroleum coke material may adversely affect gram capacity and processability.

[0068] In some embodiments, the binder is a pitch specifically mesophase pitch. In certain examples, the mesophase pitch can have a graphitization catalyst incorporated.

[0069] Granulation or heat treatment may be carried out using conventional equipment known in the art, such as a granulator comprising a stirred reactor and a temperature control module. Process parameters including stirring speed, heating rate, granulation temperature, and cooling rate may be adjusted to optimize the structural strength and isotropy of the artificial graphite. Alternatively, granulation can also be performed in a horizontal reactor with internal baffles or stirred to break up agglomerates. Additionally, by controlling these parameters, the volume average particle size Dv₅₀, as well as Dv₁₀ and Dv₉₀, can be maintained within the specified range. The final particle size distribution may also be tuned through adjustments to ensure that Dv₅₀, Dv₁₀, Dv₉₀, and the relative span (Dv₉₀−Dv₁₀) / Dv₅₀ fall within the required limits. Carbonizing Step (optional):

[0070] The foregoing heat treated or granulated particles may further undergo carbonization in accordance with example embodiments, for example, to convert at least a portion of the petroleum pitch into disordered carbon. Disordered carbon may be formed upon heating the pitch particles at a carbonization temperature under nitrogen flow. In some embodiments, the carbonization may occur in a no-oxygen or very low-oxygen environment comprising 0.1 mol % oxygen or below, preferably in the presence of an inert gas environment. The carbonization temperature may range, for example, from about 700 °C to about 1800 °C, from about 900 °C to about 1800 °C, from about 900 °C to about 1500 °C, from about 1000 °C to about 1500 °C, from about 900 °C to about 1400 °C, or from about 1000 °C to about 1200 °C, for example. Carbonization may not be as sensitive to the temperature ramping rate; however, the preferred temperature ramping rate may range from about 1 ^C per minute to about 20 ^C per minute, from about 2 ^C per minute to about 15 ^C per minute, from about 5 ^C per minute to about 12 ^C per minute, from 8 ^C per minute to about 11 ^C per minute, or about 10 ^C per minute, for example. The carbonization temperature may be maintained at the carbonization temperature for about one hour, or from about 10 seconds to about 0.5 hour. Upon carbonization, the stickiness of the petroleum pitch particles goes away, and the petroleum pitch particles solidify after cooling down to ambient temperature.

[0071] A small amount of mass loss may occur upon carbonization as the pitch particles form disordered carbon. Without being limited by theory or mechanism, the mass loss is believed to result from various reactions of the petroleum pitch that form gaseous products. Such reactions may include, for instance, dehydrogenation, polymerization with side chain lossand / or hydrogen production, condensation of aromatic rings, and decomposition of oxygen- containing groups. Gaseous products may include, for example, carbon monoxide, carbon dioxide, water vapor, hydrocarbon vapor, methane, and the like. Up to 20 wt % mass loss may occur during carbonization due to such reactions. Preferably, the amount of mass loss is 10 wt % or less, 5 wt % or less, or 2 wt % or less, for example. Graphitization Step:

[0072] Graphitization of the carbonized particles may then occur to form graphitized particles in accordance with example embodiments by heating to a graphitization temperature of about 2000 ^C to about 4000 ^C to form at least graphitized particles. This extreme heat triggers a rearrangement of carbon atoms, transforming the carbonized particles into graphite. The graphitization process imparts enhanced conductivity and other desirable properties to the particles.

[0073] Thus, in further non-limiting examples, after the carbonization step, the carbonized particles may be heated at a graphitization temperature in a no-oxygen or low-oxygen environment comprising 0.1 mol % oxygen or below. In some embodiments, graphitization may occur in an inert gas environment, such as argon or nitrogen, for example. In non-limiting examples, the graphitization temperature may range from about 2000 °C to about 4000 °C, from about 2500 °C to about 3500 °C, from about 2800 °C to about 3200 °C, or from about 2800 °C to about 3000 °C, for example. The holding temperature, or the temperature at which the sample is maintained at a constant temperature, may range from about 30 minutes to about 8 hours, from about an hour to about 7 hours, from about 2 hours to about 6 hours, from about 3 hours to about 5 hours, or about 2 hours, for example. The temperature ramping rate may be as high as possible, such as about 20 ^C per minute, but it can also take days to reach the final temperature in commercial settings if the heating ramp rate is limited. This process is performed at ambient pressure. However, other embodiments may perform graphitization at increased pressures.

[0074] Accordingly, example embodiments produce graphitized particles in a process that uses adjusted heat treatment conditions in stabilization of petroleum pitch. The process may produce graphitized particles suitable for use in negative electrodes. The graphitic particles may include primary negative electrode particles or secondary negative electrode particles, as discussed herein. In some embodiments, the secondary particles have a larger surface area than the primary surface area. The surface area of the secondary particles may be from about 0.5 m2 / g to about 5 m2 / g, from about 1 m2 / g to about 4 m2 / g, or from about 2 m2 / g to about 3 m2 / g, for example. The secondary graphitic particles may comprise microparticle active materialproduced from mesophase pitch or needle coke or petroleum coke or blends thereof. The median for the volume distribution (Dv50) of the microparticle active material ranges from 0.1 micron to 10 microns, wherein the Dv50 for the secondary particles is superior to the Dv50 for the microparticle active material. Granulating Step:

[0075] In some embodiments, an optional granulating step may be added after the stabilizing step and before the carbonizing step. Alternatively, the optional granulating step may be added after the carbonizing step and before the graphitizing step. Finally, two optional graphitization steps may be added with one added after the stabilizing step and one added after the carbonizing step. The granulating step comprises agglomerating the intermediate pitch particles by heating to a temperature from about 200 ^c to about 600 ^c using at least one binders or additives.

[0076] In some embodiments, the binder is petroleum pitch. In some embodiments, the mass ratio of the binder to the pitch particles, or of the binder to the calcined particles, or of the binder to the graphitized particles, may be selected from 1:8.5 to 1:9.5, non-limiting examples of which are 1:8.5, 1:8.6, 1:8.7, 1:8.8, 1:8.9, 1:9.0, 1:9.1, 1:9.2, 1:9.3, 1:9.4, 1:9.5, etc., and may also be selected from the interval consisting of any two of the above ratios.

[0077] The binder may comprise thermally and chemically untreated petroleum pitch, a graphitization catalyst, asphalt, phenolic resin, furfural resin, epoxy resin, lignin, starch, and any combination thereof. Graphitization Catalyst:

[0078] A “graphitization catalyst” is a substance capable of promoting conversion of a precursor material into graphite under suitable pyrolysis conditions. Suitable graphitization catalysts may lower the temperature and / or the time required to produce synthetic graphite under the pyrolysis conditions or raise the amount of synthetic graphite produced under a given set of pyrolysis conditions. A precursor to a graphitization catalyst may be converted to the graphitization catalyst in the course of being heated under the pyrolysis conditions. Unless otherwise specified or evident from context in the present disclosure, the term “graphitization catalyst” is used herein to refer equivalently to a graphitization catalyst or a graphitization catalyst precursor. In some examples, suitable graphitization catalysts may promote graphitization by virtue of the diffusion constant of one or more elements therein. Without being bound by theory or mechanism, an element with a diffusion constant larger than carbon in both the transverse and longitudinal directions may enhance graphitization of petroleum pitch and similar graphite precursors by becoming intercalated between aromatic rings inadjacent layers, thereby leaving large voids that carbon may exploit through self-diffusion to improve the graphitization rate.

[0079] Suitable graphitization catalysts that may promote graphitization through intercalation and diffusion include those containing a Group 13 element. Group 13 elements include boron, aluminum, gallium, indium, and thallium. In preferred examples, suitable graphitization catalysts containing a Group 13 element may comprise boron. Suitable boron- containing graphitization catalysts may include, but are not limited to, boric acid, organic esters of boric acid, sodium tetraborate, tetrahydroxyborate salts, orthoborate salts, metaborate salts, triborate salts, tetraborate salts, pentaborate salts, octaborate salts, boronic acids, boronate esters, boron oxides, boron carbides, the like, or any combination thereof.

[0080] In some examples, suitable graphitization catalysts may promote graphitization by a dissolution-precipitation mechanism (i.e., a carbon dissolution-precipitation mechanism). Without being bound by theory or mechanism, graphitization catalysts promoting graphitization by dissolution-precipitation may dissolve carbon (e.g., amorphous carbon) and then re-precipitate the dissolved carbon in ordered graphitic layers. Suitable graphitization catalysts that may promote graphitization through dissolution and precipitation include those containing a Group 8-10 element. Group 8-10 elements include iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium, and platinum. In preferred examples, suitable graphitization catalysts containing a Group 8-10 element may comprise iron, cobalt, or nickel. Suitable graphitization catalysts containing a Group 8-10 element may include, but are not limited to, Fe2O3, Fe3O4, Fe metal, Co metal, Ni metal, Fe-Ni alloys, Co-Ni alloys, Fe-Co alloys, Ni-Co alloys, iron carbides, the like, or any combination thereof.

[0081] In some examples, suitable graphitization catalysts may promote graphitization by a carbide formation-decomposition mechanism. Without being bound by theory or mechanism, graphitization catalysts promoting graphitization by carbide formation-decomposition may form an initial metal carbide reaction product that subsequently decomposes to produce graphite and free metal. Suitable graphitization catalysts that may promote graphitization through carbide formation include those containing a Group 4-7 element. Group 4-7 elements include titanium, vanadium, chromium, manganese, zirconium, niobium, molybdenum, hafnium, tantalum, tungsten, and rhenium. In preferred examples, suitable graphitization catalysts containing a Group 4-7 element may comprise titanium, vanadium, chromium, or manganese. Suitable graphitization catalysts containing a Group 4-7 element may include, but are not limited to, Ti metal, V metal, Cr metal, Mn metal, titanium oxide, vanadium oxide, chromium oxide, manganese dioxide, and the like.

[0082] Additional graphitization catalysts that may be suitable for use herein 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. Accordingly, the graphitization catalyst or the precursor thereof may comprise a compound containing at least one of 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. Suitable compounds containing an element from the foregoing groups of the Periodic Table include, but are not limited to, oxides, carbides, salts, coordination compounds, and any combination thereof.

[0083] In some embodiments, the binder may comprise asphalt, phenolic resin, furfural resin, epoxy resin, lignin, starch, or any combination thereof. In other embodiments, graphitic particles may be produced from petroleum pitch by adjusting the heat treatment conditions during stabilization at or above the softening point of the petroleum pitch without any binders or additives for agglomeration. Further, the heating ramp rate during stabilization may be from about 0.5 ^C per minute to about 30 ^C per minute, from about 1 ^C per minute to about 20 ^C per minute, from about 2 ^C per minute to about 15 ^C per minute, from about 3 ^C per minute to about 10 ^C per minute, from about 5 ^C per minute to about 7.5 ^C per minute, for example. De-Agglomeration Step:

[0084] After converting the petroleum pitch to carbonized particles, a de-agglomeration step may be performed in accordance with example embodiments. A de-agglomeration step may be added after the grinding step. A de-agglomeration step may be added after the stabilization step. A de-agglomeration step may be added after the optional granulating step. A de-agglomeration step may be added after the graphitization step. Alternatively, a de- agglomeration step may be added after the optional granulating step and after the carbonizing step.

[0085] In de-agglomeration after the carbonizing step, the carbonized particles may be broken into particles Dv50 ranging, for example, from 1 µm to 50 µm, from 5 µm to 35 µm, from 10 µm to 20 µm, from 12 µm to 18 µm, or from 14 µm to 16 µm, for example. This may be accomplished by jet milling, for example. As discussed above, jet milling may be especially desirable since it typically produces narrow particle size distributions. Moreover, because jet milling equipment lacks blades and other direct physical structures, there is a lower likelihood of introducing contaminants from the mill (e.g., due to micro abrasion of the milling equipment) compared to other types of de-agglomeration processes. Other suitable grinding processes may be used for de-agglomeration, including impact mills and hammer mills. Inaccordance with some embodiments, the de-agglomeration may be performed at ambient temperature and pressure but under a constant flow of nitrogen or air. However, other embodiments may perform de-agglomeration at elevated temperatures and / or pressures.

[0086] After deagglomeration of the carbonized particles, graphitization of the carbonized particles may then occur to form graphitized particles in accordance with example embodiments. Graphitization occurs when the carbonized particles enter an electric furnace where temperatures are elevated, for example, above 2800 °C. This extreme heat triggers a rearrangement of carbon atoms, transforming the carbonized particles into graphite. The graphitization process imparts enhanced conductivity and other desirable properties to the particles.

[0087] Thus, in further non-limiting examples, after the carbonization and de- agglomeration steps, the carbonized particles may be heated at a graphitization temperature in a no-oxygen or low-oxygen environment comprising 0.1 mol % oxygen or below. In some embodiments, graphitization may occur in an inert gas environment, such as argon or nitrogen, for example. In non-limiting examples, the graphitization temperature may range from about 2000 °C to about 4000 °C, from about 2500 °C to about 3500 °C, from about 2800 °C to about 3200 °C, or from about 2800 °C to about 3000 °C, for example. The holding temperature, or the temperature at which the sample is maintained at a constant temperature, may range from about 30 minutes to about 8 hours, from about an hour to about 7 hours, from about 2 hours to about 6 hours, from about 3 hours to about 5 hours, or about 2 hours, for example. The temperature ramping rate may be as high as possible, such as about 20 ^C per minute, but it can also take days to reach the final temperature in commercial settings if the heating ramp rate is limited. This process is performed at ambient pressure. However, other embodiments may perform graphitization at increased pressures.

[0088] The granulated or heat-treated product is subjected to a graphitization process at a temperature ranging from 2800 °C to 3200 °C to produce artificial graphite with a controlled degree of graphitization. In certain embodiments, the graphitization temperature is preferably maintained between 2900 °C and 3100 °C. By regulating the graphitization degree within the specified range, the resulting artificial graphite exhibits enhanced gram capacity and reduced lattice expansion during lithium intercalation.

[0089] Graphitization may be performed using conventional equipment known in the art, such as a graphitization furnace, including but not limited to an Acheson-type furnace, continuous graphitization furnaces that are inductively or direct joule-heated. Upon completion of the graphitization process, oversized particles formed due to agglomeration at hightemperatures may be removed via sieving. This post-treatment step improves the processing characteristics of the material, including slurry stability and coating uniformity. Coating Step:

[0090] In some embodiments, an optional coating step is added after the stabilization step, after the granulating step, after the carbonizing step, after the graphitization step, or any combination thereof. In preferred embodiments, the coating step is added after the graphitization step. The coating step comprises the following steps: mixing the material with an organic carbon material in a specific mass ratio, and heating at a suitable temperature (insulation temperature, such as from about 1100 °C to about 1200 °C, further such as 1150 °C, for example) to prepare secondary particles comprising a coating layer. In some embodiments, the organic carbon material may include one or more of asphalt, phenolic resin, furfural resin, and epoxy resin, or any combination thereof.

[0091] In some embodiments, the heating time (insulation time) may be from about 12 hours to about 24 hours (such as 12 hours, 15 hours, 16 hours, 18 hours, 20 hours, etc., also such as from about 12 hours to about 16 hours). In some embodiments, the coating step is carried out under inert gas conditions. In some embodiments, the coating layer in the secondary particles comprising the coating layer contains amorphous carbon.

[0092] In some non-limiting examples, before the heat preservation step of coating, the temperature may be raised to a preset temperature at a heating rate of, for example, from about 1 °C per minute to about 10 °C per minute, and then the temperature can be kept warm. Non- limiting examples of the heating rate may be 1 °C / min, 1.3 °C / min, 1.4 °C / min, 1.5 °C / min, 1.6 °C / min, 1.8 °C / min, 2 °C / min, 3 °C / min, 4 °C / min, 5 °C / min, 6 °C / min, 8 °C / min, 10 °C / min, etc. In some non-limiting examples, the heating rate from room temperature (such as from about 20 °C to about 30 °C, further such as about 25 °C, for example) to a preset temperature (such as from about 1100 °C to about 1200 °C) may be from about 1.3 °C / min to about 2.5 °C / min, and further such as from about 1.5 °C / min to about 1.8 °C / min. In some embodiments, in the coating step, after the material is mixed with the organic carbon material (such as asphalt), it can also be preheated at a relatively low temperature (from about 500 °C to about 600 °C) to fully melt the organic carbon material (such as asphalt), and then heated to a preset temperature (such as from about 1100 °C to about 1200 °C, further such as about 1150 °C) for carbonization. The temperature may be raised to a preset temperature at a heating rate of from about 1 °C / min to about 5 °C / min (further such as from about 1.3 °C / min to about 2 °C / min) and then preheated (from about 500 °C to about 600 °C insulation), and non-limiting examples of the heating rate are 1 °C / min, 1.5 °C / min, 2 °C / min, 2.5 °C / min, 3 °C / min,3.5 °C / min, 4 °C / min, 4.5 °C / min, 5 °C / min, etc. It should also be noted that when coating the amorphous carbon layer, the heating rate needs to be reasonably controlled. If the heating rate is too fast, it will easily lead to more defects in the coating layer carbon. When there are more defects on the surface of the carbon particles, it will be detrimental to the battery cycle performance.

[0093] In the step of coating the amorphous carbon layer on the surface of the material, the mass of the organic carbon material (such as asphalt) accounts for the total mass of the material and the organic carbon material (such as asphalt) The proportion of the mass of the amorphous carbon layer in the secondary particulate carbon in the first aspect mentioned above can refer to the mass proportion of the amorphous carbon layer in the secondary particulate carbon in the first aspect. In some embodiments, the mass of the organic carbon material (such as asphalt) accounts for ≤ 3.3 % of the total mass of the material and the organic carbon material (such as asphalt), and can further be from about 1.3 % to about 3.3 %, and may also be selected from any of the following percentages or any two percentage intervals: 1.3 %, 1.4 %, 1.5 %, 1.6 %, 1.7 %, 1.8 %, 1.9 %, 2.0 %, 2.1 %, 2.2 %, 2.3 %, 2.4 %, 2.5 %, 2.6 %, 2.7 %, 2.8 %, 2.9 %, 3.0 %, 3.1 %, 3.2 %, 3.3 %, etc.

[0094] The present disclosure will now be described with further reference to the drawing. FIGURE is a block diagram of an illustrative process 100 for processing petroleum pitch according to the present disclosure. In process 100, the petroleum pitch goes through a grinding step 102 first, then a stabilization step 104, a carbonization step 106, and a graphitization step 108. Grinding step 102 may employ a grinding apparatus that may be operated in a batchwise manner or a continuous manner. Batchwise grinding apparatuses may employ, for example, ball milling and like techniques. Continuous grinding apparatuses may employ, for example, jet milling, Wiley milling, extrusion, and related techniques. In particular examples, grinding in the disclosure herein may be performed by jet milling. Jet milling may be especially desirable since it typically produces narrow particle size distributions. Moreover, because jet milling equipment lacks blades and other direct contact grinding structures, there is a lower likelihood of introducing contaminants from the mill (e.g., due to micro abrasion of the milling equipment) compared to other types of grinding processes. Moreover, the processing of petroleum pitch can target maintaining or agglomerating particles. In the case where particle size is maintained, an additional processing step (not shown) can be added involving agglomerating particles either before or after the graphitization step 108. In such cases, the agglomeration step (not shown in FIGURE) would involve adding a binder (discussed above), up to about 20 wt%. It is to be appreciated that some of the process steps may beinterchangeable or added. For example, a deagglomeration step (not shown) may be added before or after the graphitization step 108. Additional details on the grinding step 102 may be described above.

[0095] Stabilization step 104 may occur at a stabilization temperature at least 5 °C above the softening temperature, or at least 10 °C above the softening temperature, or at least 15 °C above the softening temperature, or at least 20 °C above the softening temperature, or at least 25 °C above first softening temperature, or at least 50 °C above the softening temperature, or at least 75 °C above the softening temperature, or at least 100 °C above the softening temperature, or at least 150 °C below the first softening temperature, such as within a range of about 180 °C to about 500 °C, or about 200 °C to about 250 °C, or about 250 °C to about 300 °C, or about 200 °C to about 300 °C, or about 350 °C to about 450 °C. The temperature of the petroleum pitch may be maintained at this stabilization temperature over a time period of about 10 minutes to about 24 hours, or about 10 minutes to about 6 hours, or about 30 minutes to about 20 hours, or about 30 minutes to 6 hours, or about 1 hour to about 18 hours, or about 30 minutes to about 2 hours, or about 2 hours to about 6 hours. Additional details on the stabilization step 104 may be described above.

[0096] In carbonization step 106, the petroleum pitch is heated to a temperature range of 700 °C to 1800 °C as discussed above. The temperature ramping rate ranges in between 1 ^C per minute to about 20 ^C per minute, from about 2 ^C per minute to about 15 ^C per minute, from about 5 ^C per minute to about 12 ^C per minute, from 8 ^C per minute to about 11 ^C per minute, or about 10 ^C per minute, for example. The carbonization temperature may be maintained at the carbonization temperature for about two hours, one hour, or from about 0 hour to about 0.5 hour, for example. Additional details on the carbonization step 106 may be described above.

[0097] In other embodiments, the carbonization step 106 may be executed after a grinding step (not shown). Carbonization is a heat treatment process of non-graphite carbon-based materials under relatively low temperature conditions (such as 1100 ± 50 °C, for example) under an inert environment or carbon dioxide environment. In example embodiments, the carbonization step is performed under nitrogen flow. After the carbonization treatment, the carbon-based particles shrink and the structure becomes denser. Non-graphite carbon-based materials refer to carbon in which the carbon is not entirely graphite and may not contain any graphite components.

[0098] In graphitization step 108, the carbonized particles may be heated at a graphitization temperature in a no-oxygen or low-oxygen environment comprising 0.1 mol% oxygen orbelow. The non-graphite carbon-based materials undergo a graphitization treatment under relatively high temperature conditions (such as from about 2800 °C to about 3500 °C). After graphitization treatment, the hexagonal carbon atom planar network is transformed from a disordered arrangement into two-dimensional space such as a chaotic layer structure or amorphous carbon) to an ordered arrangement of graphite structure in three-dimensional space. In some embodiments, graphitization may occur in an inert gas environment, such as argon or nitrogen, for example. In non-limiting examples, the graphitization temperature may range from 2000 °C to 4000 °C, 2500 °C to 3500 °C, 2700 °C to 3200 °C, or 2800 °C to 3000 °C for example. The holding temperature, or the temperature at which the sample is maintained at a constant temperature, may range from 30 minutes to 8 hours, an hour to 7 hours, 2 hours to 6 hours, 3 hours to 5 hours, or 2 hours for example. The temperature ramping rate may be as high as possible, such as 20 ^C per minute for example, but can also take days if heating ramp rate is limited. This process is performed at ambient pressure. However, other embodiments may perform graphitization at increased pressures. Additional details on the graphitization step 108 may be described above.

[0099] Accordingly, example embodiments produce graphitized particles in a process that uses adjusted heat treatment conditions in stabilization of petroleum pitch. The process may produce graphitic particles suitable for use in negative electrodes. The graphitic particles may include primary negative electrode particles or secondary negative electrode particles, as discussed herein. In some embodiments, the secondary particles have a larger surface area than the surface area of the primary particles. The surface area of the secondary particles may be from about 0.5 m2 / g to about 5 m2 / g, from about 1 m2 / g to about 4 m2 / g, or from about 2 m2 / g to about 3 m2 / g, for example. Secondary Battery:

[0100] According to a secondary aspect of the present application, there is provided a secondary battery comprising a negative electrode plate. The negative electrode plate includes negative active material, wherein the negative active material comprises the artificial graphite as described in the first aspect of the present application.

[0101] By incorporating the artificial graphite of the first aspect, the secondary battery exhibits excellent fast charging rate, reduced volumetric expansion during charge-discharge cycling, thereby enhancing both the cycle life and safety performance of the battery. Additionally, the use of artificial graphite contributes to an increase in the energy density of the secondary battery.

[0102] The secondary battery further comprises a positive electrode plate and an electrolyte. During operation, active ions are reversibly intercalated and de-intercalated between the positive and negative electrode plates. The electrolyte functions as an ionic conductor, facilitating ion transport between the electrodes during the charging and discharging processes. Preparation of primary and secondary negative electrode particles

[0103] Example embodiments may process the petroleum pitch to form graphitized particles, as described herein. In accordance with example, embodiments, the graphitized particles may comprise primary negative electrode particles and / or secondary negative electrode particles. For example, a process for forming graphitized particles may include grinding, stabilizing, carbonization, and graphitization. Optional steps may include, for example, granulating and / or de-agglomeration. In embodiments, the source of carbon for primary negative electrode particles or secondary negative electrode particles may be a mixture of petroleum pitch, raw coke material, and optionally graphitization catalyst.

[0104] The preparation of primary negative electrode particles, secondary negative electrode particles, or both involve carbonizing and graphitizing steps. The source of carbon such as pitch particles may be carbonized at relatively low temperature conditions (such as 1100 ± 50 °C), and the carbonized particles shrink and the structure becomes more compact. Non-graphite may be graphitized, and the hexagonal carbon atom plane network is transformed from a disordered arrangement in two-dimensional space (such as a chaotic layer structure or amorphous carbon) to an ordered arrangement of graphite structure in three-dimensional space.

[0105] When preparing secondary negative electrode particles from primary negative electrode particles or graphitized particles, in a process of “granulation in the molten state of the binder”, the binder (such as petroleum pitch or epoxy or phenolic resin or asphalt as discussed above) plays the role of a binder on the one hand, and on the other hand, the free carbon α, asphaltene β, and other carbon substances in the binder are filled on the surface of micro-particles of carbon in a flowing state. After subsequent carbonization, graphitization and other processes, a secondary negative electrode particle with a preset particle size and a more uniform surface may be obtained. In addition, the optional granulation step may also include a crushing sub-step to depolymerize the polymerized particles, so as to better control the particle size and distribution of the secondary negative electrode particles. The granulation step may be performed in any reactor capable of performing the granulation step including an extruder, a mixer, a vessel, or any combination thereof.

[0106] “In the molten state of the binder” is a low temperature condition relative to carbonization, such as from 200 °C to 600 °C or from 500 °C to 600 °C, and non-limiting examples are 500 °C, 550 °C, 600 °C, etc. It can be understood that granulation is carried out at a temperature higher than the softening point of the pitch particle, and the required time may be from about 2 hours to about 10 hours. In some non-limiting examples, the temperature may be raised to a preset temperature at a heating rate of, for example, 1 °C / min to 5 °C / min and then kept warm. Non-limiting examples of the heating rate include 1 °C / min, 1.2 °C / min, 1.25 °C / min, 1.3 °C / min, 1.35 °C / min, 1.4 °C / min, 1.5 °C / min, 2 °C / min, 2.5 °C / min, 3 °C / min, 3.5 °C / min, 4 °C / min, 4.5 °C / min, 5 °C / min, etc. In some non-limiting examples, it may take from about 4 hours to about 6 hours to heat from room temperature (such as from about 20 °C to about 30 °C, further such as 25 °C) to a preset temperature (such as from about 500 °C to 600 °C), and the heating rate may be from about 1.3 °C / min to about 2.5 °C / min, and further may be from about 1.3 °C / min to about 2.4 °C / min.

[0107] In some embodiments, each occurrence of the carbonization independently includes the following steps: heating treatment (insulation treatment) at from about 1050 °C to about 1150 °C (such as 1100 °C, for example). In some embodiments, the heating time (insulation time) is from about 24 hours to about 72 hours (such as 24h, 36h, 40h, 48h, etc., and also 36h to 40h); in some embodiments, the carbonization is carried out under inert gas conditions. In some non-limiting examples, before the insulation step of carbonization, the temperature may be raised to a preset temperature at a heating rate of, for example, from about 1 °C / min to about 10 °C / min, and then the temperature is kept warm. Non-limiting examples of the heating rate may be 1 °C / min, 1.3 °C / min, 1.4 °C / min, 1.5 °C / min, 1.6 °C / min, 1.8 °C / min, 2 °C / min, 3 °C / min, 4 °C / min, 5 °C / min, 6 °C / min, 8 °C / min, 10 °C / min, etc. In some non-limiting examples, it takes from about 10 hours to about 12 hours to heat from room temperature (such as from about 20 ℃ to about 30 ℃, further such as 25 ℃) to a preset temperature (such as from about 1050 ℃ to about 1150 ℃), and the heating rate may be from about 1.3 ℃ / min to about 2.5 ℃ / min, further may be from about 1.4 ℃ / min to about 2 ℃ / min, and further may be from about 1.5 ℃ / min to about 1.8 ℃ / min.

[0108] In some embodiments, each occurrence of the graphitization independently comprises the following steps: heating treatment at a temperature of above 2800 °C. In some embodiments, the heating temperature (insulation temperature) is from about 2850 °C to about 3100 °C (such as 3000 °C, for example). In some embodiments, the heating time (insulation time) is from about 30 hours to about 96 hours (such as 36 hours, 40 hours, 48 hours, 60 hours, 72 hours, etc., such as from about 36 hours to about 48 hours). In some embodiments, thegraphitization is carried out under inert gas conditions. In some non-limiting examples, before the graphitization heat preservation step, the temperature can be raised to a preset temperature at a heating rate of, for example, from about 1 °C / min to about 15 °C / min, and then the temperature can be kept warm. Non-limiting examples of the heating rate include 1 °C / min, 1.5 °C / min, 2 °C / min, 2.5 °C / min, 3 °C / min, 3.5 °C / min, 4 °C / min, 4.5 °C / min, 5 °C / min, 6 °C / min, 8 °C / min, 10 °C / min, 12 °C / min, 15 °C / min, etc. In some non-limiting examples, it takes from about 24 hours to about 36 hours to heat from room temperature (such as from about 20 °C to about 30 °C, further such as 25°C, for example) to a preset temperature (such as from about 2850 °C to about 3100 °C), and the corresponding heating rate may be from about 1.3 °C / min to about 2.5 °C / min, and further may be from about 1.5 °C / min to about 2 °C / min.

[0109] In the present application, when preparing primary negative electrode particles or secondary negative electrode particles, the “inert gas” involved may be used as long as it can avoid side reactions of the gas, including oxygen-free conditions to avoid oxidation of chemical components in the raw materials under high temperature conditions. In some non-limiting examples, the inert gas includes one or more nitrogen, helium, argon, neon, etc. In some non- limiting examples, the inert gas includes nitrogen.

[0110] In some embodiments, each occurrence of the inert gas condition is independently a nitrogen condition.

[0111] By controlling the relevant parameters of the carbonization, graphitization, granulation, coating and other steps, and the coordination between the parameters, the compounding of primary negative electrode particles or secondary negative electrode particles may be better controlled, so that the tortuosity can be controlled within a more appropriate range, which is conducive to gas production and discharge while maintaining good battery cell cycle performance and extending battery life. For example, in the process of coating amorphous carbon on the surface of secondary negative electrode particles, the amount of amorphous carbon coating may be better controlled by controlling the amount of organic carbon material (such as asphalt) and the temperature curve, thereby improving the fast-charging performance of the battery while maintaining good cycle performance.

[0112] In some embodiments, a single graphitized particle is prepared by a method comprising the following steps in sequence: crushing the petroleum pitch, grading, carbonizing at from about 1050 °C to about 1150 °C, graphitizing at a temperature above 2800 °C, and screening to obtain the single particle carbon with a certain dimension. Before carbonizing the graded material, a mixing step may be added to obtain a material with a preset particle size and distribution.

[0113] In some embodiments, the steps of preparing single graphitized particle include: crushing and classifying the carbon source such as petroleum pitch, raw coke raw materials, petroleum coke, or any combination thereof, mixing, carbonization, and graphitization.

[0114] In the process of preparing single graphitized particle, the temperature and time conditions of the carbonization and graphitization may be selected from any suitable temperature conditions mentioned above independently or in combination.

[0115] In some embodiments, the secondary negative electrode particles are prepared by a method comprising the following steps in sequence: preparing the single graphitized particle, mixing the single graphitized particle and the binder, granulating at from about 500 °C to about 600 °C, carbonizing at from about 1050 °C to about 1150 °C, graphitizing at a temperature above 2800 °C, optionally coating at from about 1100 °C to about 1200 °C, and screening to obtain the secondary negative electrode particles.

[0116] In some embodiments, the steps of preparing secondary negative electrode particles include: crushing and grading the carbon source such as petroleum pitch, raw materials (such as raw coke raw materials, further such as petroleum coke), or any combination thereof, mixing (mixing the carbon source and binders (such as asphalt)) → granulation (low-temperature heat treatment) → crushing (deagglomerating agglomerated particles) → carbonization → graphitization → coating with an amorphous carbon layer (optional step).

[0117] In the process of preparing secondary negative electrode particles, the temperature and time conditions of granulation, carbonization, graphitization, and coating may be selected from any suitable temperature conditions mentioned above independently or in combination in any suitable manner.

[0118] Below are some embodiments of the present application are described. Some of the embodiments described below are exemplary and cannot be construed as limiting the present application. In the embodiments, if the technology or conditions are not specified, they are carried out according to the description above, or according to the technology or conditions described in the document in this area or according to the product specification. The reagents used or the instruments that do not specify the manufacturer are conventional products that can be obtained commercially, or can be synthesized in a conventional manner by commercially available products.

[0119] In the present application, when preparing single graphitized particles, the heating program is involved. If not specifically limited, the heating rate may be selected from about 0.5 °C / min to about 15 °C / min. When it comes to the cooling program, if not specifically limited, the temperature may be cooled by furnace cooling or the like. For example, the heatingrate before carbonization may be from about 1 °C / min to about 10 °C / min, and the heating rate before graphitization may be from about 1 °C / min to about 15 °C / min.

[0120] In the process of preparing secondary negative electrode particles, a heating program is involved. If not specifically limited, the heating rate may be selected from about 0.5 °C / min to about 15 °C / min. When a cooling program is involved, if not specifically limited, the temperature may be cooled by furnace cooling or the like. For example, the heating rate before bonding granulation may be from about 1 °C / min to about 5 °C / min, the heating rate before carbonization may be from about 1 °C / min to about 10 °C / min, the heating rate before graphitization may be from about 1 °C / min to about 15 °C / min, and the heating rate before coating amorphous carbon may be from about 1 °C / min to about 10 °C / min. If a preheating program (such as from about 500 °C to about 600 °C) is set before coating, a heating rate of from about 1 °C / min to about 5 °C / min may be used.

[0121] The negative electrode plate comprises a negative electrode current collector and a negative electrode film disposed on at least one surface of the current collector. In certain embodiments, the current collector includes two opposing surfaces along its thickness direction, and the negative electrode film may be laminated on either one or both of these surfaces.

[0122] The negative electrode current collector is formed from a material exhibiting high electrical conductivity and mechanical strength, serving the dual function of electron conduction and current collection. In some embodiments, the current collector may be a copper foil.

[0123] The negative electrode film includes a negative active material, which comprises the artificial graphite described in the first aspect of the present application. Unless otherwise specified, all parameters related to the negative electrode film refer to a single-sided configuration. In cases where the film is applied to both sides of the current collector, the parameters of either side individually conforming to the specified ranges shall be considered within the scope of protection of the present application. The compacted density, areal density, and other relevant parameters refer to values obtained after cold compaction during battery assembly.

[0124] In certain embodiments, the negative active material may further include one or more additional active materials suitable for use in the negative electrode of a secondary battery. Examples of such materials include other forms of graphite, mesophase carbon microspheres (MCMB), hard carbon, soft carbon, silicon-based materials, and tin-based materials.

[0125] The negative electrode film may further comprise a binder. Suitable binders include, but are not limited to, polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), styrene-butadiene rubber (SBR), sodium alginate (SA), polymethacrylic acid (PMAA), and carboxymethyl chitosan (CMCS).

[0126] In some embodiments, the negative electrode film may also include a thickener, such as sodium carboxymethyl cellulose (CMC-Na).

[0127] Additionally, the negative electrode film may comprise a conductive agent to enhance electrical conductivity. Suitable conductive agents include graphite, superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers Post-Processing: Production of Negative Electrode

[0128] Following graphitization, additional post-processing steps may come into play. Shaping, classification, or coating might be applied to ensure optimal packaging and bolster performance within lithium-ion batteries. The specifics of post-processing may vary based on the particular requirements of the applications. Example embodiments of the production of negative electrode or negative electrode are now described.

[0129] The negative electrode sheet includes a negative electrode current collector and a negative electrode film layer arranged on at least one surface of the negative electrode current collector. Further, at least one of the negative electrode film layers includes the aforementioned negative electrode active material layer, and any of the negative electrode active material layers contains a negative electrode active substance.

[0130] As a non-limiting example, the negative electrode current collector has two surfaces opposite to each other in its thickness direction, and further, the negative electrode film layer is disposed on any one or both of the two opposite surfaces of the negative electrode current collector.

[0131] As a non-limiting example, when negative electrode film layers are disposed on both sides of the negative electrode current collector, the negative electrode film layers on both sides may be the same or different.

[0132] As a non-limiting example, when negative electrode active material layers are disposed on both sides of a negative electrode current collector, the negative electrode active material layers on both sides may be the same or different.

[0133] In the present application, unless otherwise specified, “disposed on at least one side surface of the current collector” means disposed on at least one side of the current collector inthe thickness direction of the current collector, and either side may be independently in direct contact with the current collector or not in direct contact with the current collector.

[0134] As a non-limiting example, the aforementioned negative electrode active material layer is disposed on at least one side of the negative electrode current collector. In some embodiments, the negative electrode active material layer is disposed on at least one side surface of the negative electrode current collector and may be disposed on one surface of the negative electrode current collector or may be disposed on both surfaces of the negative electrode current collector. In some embodiments, at least one of the negative electrode active material layers is in direct contact with the negative electrode current collector, in which case the negative electrode active material layer is in direct contact with at least one side surface (one or two surfaces) of the negative electrode current collector.

[0135] In some embodiments, the negative electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, copper foil may be used. The composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material substrate. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0136] In some embodiments, the negative electrode active material may adopt a negative electrode active material for a battery known in the art. As a non-limiting example, the negative electrode active material may include one or more of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, for example. The silicon-based material may be selected from one or more of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from one or more of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these substances or materials, and other traditional substances or materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0137] In some embodiments of the present application, the negative electrode active material of the negative electrode active material layer is mainly carbon-based particles including artificial graphite, natural graphite, soft carbon, hard carbon, or any combination thereof. In some embodiments, the mass proportion of the carbon-based particles in thenegative electrode active material of the negative electrode active material layer is greater than 50%. In some embodiments, the mass proportion of the carbon-based particles in the negative electrode active material of the negative electrode active material layer is selected from 80% to 100%. In some embodiments, the mass proportion of the carbon-based particles in the negative electrode active material of the negative electrode active material layer is selected from 90% to 100%. In some embodiments, the mass proportion of the carbon-based particles in the negative electrode active material of the negative electrode active material layer is selected from 95% to 100%. In some embodiments, the mass proportion of the carbon-based particles in the negative electrode active material of the negative electrode active material layer is 100%. The mass proportion of the carbon-based particles in the negative electrode active material of the negative electrode active material layer can also be selected from any one of the following percentages or a numerical range consisting of any two of the following percentages: 60%, 70%, 75%, 80%, 82%, 84%, 85%, 86%, 88%, 90%, 92%, 94%, 95%, 96%, 97%, 98%, 99%, 100%, etc.

[0138] In some embodiments of the present application, the carbon-based particles are mainly graphite materials. In some embodiments, the carbon-based particles contain a graphite material with a mass ratio of greater than 50%. In some embodiments, the carbon-based particles contain a graphite material selected from 80% to 100% by mass. In some embodiments, the carbon-based particles contain a graphite material selected from 90% to 100% by mass. In some embodiments, the carbon-based particles contain a graphite material selected from 95% to 100% by mass. In some embodiments, the carbon-based particles contain a graphite material with a mass ratio of 100%. The mass ratio of graphite material in the carbon- based particles can also be selected from any of the following percentages or from the numerical interval consisting of any two of the following percentages: 60%, 70%, 75%, 80%, 82%, 84%, 85%, 86%, 88%, 90%, 92%, 94%, 95%, 96%, 97%, 98%, 99%, 100%, etc.

[0139] In some embodiments of the present application, the negative active material of the negative active material layer is mainly a graphite material. In some embodiments, the negative active material of the negative active material layer contains a graphite material with a mass percentage greater than 50%. In some embodiments, the negative active material of the negative active material layer contains a graphite material with a mass percentage selected from 80% to 100%. In some embodiments, the negative active material of the negative active material layer contains a graphite material with a mass percentage selected from 90% to 100%. In some embodiments, the negative active material of the negative active material layer contains a graphite material with a mass percentage selected from 95% to 100%. The massproportion of the graphite material in the negative electrode active material of the negative electrode active material layer can also be selected from any one of the following percentages or from a numerical range consisting of any two of the following percentages: 60%, 70%, 75%, 80%, 82%, 84%, 85%, 86%, 88%, 90%, 92%, 94%, 95%, 96%, 97%, 98%, 99%, 100%, for example.

[0140] In some embodiments, the negative active material of the negative active material layer contains 100% by mass of graphite material. In this case, the carbon-based particles are graphitized particles, the single carbon particles are single graphitized particles, and the secondary particles are secondary negative electrode particles.

[0141] When carbon-based materials are used as the main negative electrode active material in the negative electrode active material layer, compared with other types of negative electrode sheets with high silicon content, the negative electrode sheet has lower expansion, a more stable solid electrolyte interface (SEI) film, and better battery safety.

[0142] When graphite is used as the main negative electrode active material in the negative electrode active material layer, in the negative electrode active material layer, the carbon-based particles are mainly graphite particles, the single-particle carbon is mainly single-particle graphite, and the secondary particles are mainly secondary-particle graphite. At this time, the advantages of graphite such as good conductivity, high initial efficiency, and wide sources can be fully utilized.

[0143] When artificial graphite is used as the negative electrode active material, the morphology and particle size consistency of the negative electrode active particles can be better controlled, thereby making the battery performance more stable.

[0144] In this application, when “mainly” is used to indicate the content of a substance, unless otherwise specified, the content percentage is greater than 50%, and can also be selected from ≥60%, ≥70%, ≥80%, ≥90%, ≥95%, ≥96%, ≥98%, ≥99%, 60%-100%, 70%-100%, 80%- 100%, 90%-100%, 90%-100%, 95%-100%, 96%-100%, 98%-100%, 100%, 99% to 100%, etc., and can also be selected from any of the following percentages or from the numerical interval consisting of any two of the following percentages: 60%, 65%, 70%, 75%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 100%, etc. The aforementioned description of the composition of the carbon-based particles and the description of the composition of the negative active material can all be applied to the definition here, such as “the carbon-based particles are mainly graphite materials”, “the negative active material of the negative active material layer is mainly carbon-based particles”, “the negative active material of the negative active material layer is mainly graphite materials”, etc.

[0145] In some embodiments of the present application, the negative electrode active material layer has one or more of the following characteristics (one, two, or three characteristics):

[0146] (ta1) the Dv50 of the single carbon particle is selected from 13 μm to 14 μm (a non- limiting example of the Dv5 of the single carbon particle is any one of the following values or a numerical interval consisting of any two of the following values: 13 μm, 13.1 μm, 13.2 μm, 13.3 μm, 13.4 μm, 13.5 μm, 13.6 μm, 13.7 μm, 13.8 μm, 13.9 μm, 14 μm, etc.);

[0147] (ta2) the Dv50 of the secondary carbon particles is selected from 9.5 μm to 10.5 μm (a non-limiting example of the Dv50 of the secondary carbon particles is any one of the following values or a numerical range consisting of any two of the following values: 9.5 μm, 9.6 μm, 9.7 μm, 9.8 μm, 9.9 μm, 10.0 μm, 10.1 μm, 10.2 μm, 10.3 μm, 10.4 μm, 10.5 μm, etc.); and

[0148] (ta3) the difference between the Dv50 of the single carbon particle and the Dv50 of the secondary carbon particle is selected from 3 μm to 4 μm (a non-limiting example of the difference between the Dv50 of the single carbon particle and the Dv50 of the secondary carbon particle is any one of the following values or a numerical range consisting of any two of the following values: 3 μm, 3.1 μm, 3.2 μm, 3.3 μm, 3.4 μm, 3.5 μm, 3.6 μm, 3.7 μm, 3.8 μm, 3.9 μm, 4 μm, etc.).

[0149] In some embodiments of the present application, the Dv99 of the single carbon particle is greater than the Dv99 of the secondary carbon particle.

[0150] In some embodiments of the present application, the negative electrode active material layer further has one or more of the following characteristics (one, two or three characteristics):

[0151] (tb1) the Dv99 of the single carbon particle is selected from 37 μm to 44 μm (a non- limiting example of the Dv99 of the single carbon particle is any one of the following values or a numerical range consisting of any two of the following values: 37 μm, 37.5 μm, 38 μm, 38.5 μm, 39 μm, 39.5 μm, 40 μm, 40.5 μm, 41 μm, 41.5 μm, 42 μm, 42.5 μm, 43 μm, 43.5 μm, 44 μm, etc.);

[0152] (tb2) D v 99 of the secondary carbon particles is selected from 31 μm to 38 μm (non-limiting examples of Dv99 of the secondary carbon particles include any one or two of the following values: 31 μm, 31.5 μm, 32 μm, 32.5 μm, 33 μm, 33.5 μm, 34 μm, 34.5 μm, 35 μm, 35.5 μm, 36 μm, 36.5 μm, 37 μm, 37.5 μm, 38 μm, etc.); and

[0153] (tb3) The difference between Dv99 of the single carbon particle and Dv99 of the secondary carbon particle is selected from 4 μm to 6 μm (a non-limiting example of the difference between Dv99 of the single carbon particle and Dv99 of the secondary carbon particle is any one of the following values or a numerical range consisting of any two of the following values: 4 μm, 4.2 μm, 4.4 μm, 4.5 μm, 4.6 μm, 4.8 μm, 5 μm, 5.2 μm, 5.4 μm, 5.5 μm, 5.6 μm, 5.8 μm, 6 μm, etc.).

[0154] In some embodiments of the present application, the Dv10 of the single carbon particle is greater than the Dv10 of the secondary carbon particle.

[0155] In some embodiments of the present application, the negative electrode active material layer further has one or more of the following characteristics (one, two or three characteristics):

[0156] (tc1) the Dv10 of the single carbon particle is selected from 5 μm to 7 μm (a non- limiting example of the Dv10 of the single carbon particle is any one of the following values or a numerical range consisting of any two of the following values: 5 μm, 5.2 μm, 5.4 μm, 5.5 μm, 5.6 μm, 5.8 μm, 6 μm, 6.2 μm, 6.4 μm, 6.5 μm, 6.6 μm, 6.8 μm, 7 μm, etc.);

[0157] (tc2) Dv10 of the secondary particulate carbon is selected from 3.5 μm to 5.5 μm (non-limiting examples of Dv100 of the secondary particulate carbon are any one of the following values or a numerical range consisting of any two of the following values: 3.5 μm, 3.6 μm, 3.8 μm, 4 μm, 4.2 μm, 4.4 μm, 4.5 μm, 4.6 μm, 4.8 μm, 5 μm, 5.2 μm, 5.4 μm, 5.5 μm, etc.); and

[0158] (tc3) The difference between Dv10 of the single carbon particle and Dv99 of the secondary carbon particle is selected from 1 μm to 2 μm (a non-limiting example of the difference between Dv10 of the single carbon particle and Dv99 of the secondary carbon particle is any one of the following values or a numerical range consisting of any two of the following values: 1 μm, 1.1 μm, 1.2 μm, 1.3 μm, 1.4 μm, 1.5 μm, 1.6 μm, 1.7 μm, 1.8 μm, 1.9 μm, 2 μm, etc.).

[0159] In some embodiments, the Dv50 of the single carbon particle is selected from 13 μm to 14 μm, and the Dv50 of the secondary carbon particle is about 10 μm; further, in some embodiments, the Dv99 of the single carbon particle is about 40.5 μm, and the Dv99 of the secondary carbon particle is about 34 μm; further, in some embodiments, the Dv10 of the single carbon particle is about 6.3 μm, and the Dv10 of the secondary carbon particle is about 4.5 μm. The several “approximate numbers” involved here can each independently indicate that the floating range based on 10 μm is allowed to be shown as ±0.01 μm, ±0.02 μm, ±0.05 μm, ±0.1 μm, etc.

[0160] By controlling the particle size and distribution of single-particle carbon and secondary-particle carbon, the multi-dimensional performance of tortuosity, porosity and compaction degree can be better balanced, thereby accelerating gas production and discharge while achieving better cycle performance and power performance.

[0161] Furthermore, controlling the difference in particle size between primary negative electrode particles and secondary negative electrode particles is more conducive to fully leveraging the compounding advantages of the two, which is beneficial for reducing tortuosity and gas emission, maintaining good battery cell cycle performance, and extending battery life.

[0162] In some embodiments of the present application, the secondary negative electrode particles include a plurality of primary negative electrode particles and a binder. In this case, the binder may be used to aggregate the primary negative electrode particles into secondary negative electrode particles. In some embodiments, the primary negative electrode particles are single graphitized particles.

[0163] In other embodiments, the secondary negative electrode particles do not have any binder.

[0164] Furthermore, in some embodiments, the graphitized particle has one or more of the following characteristics (may be one, two, three or four characteristics):

[0165] (td1) the Dv99 of the graphitized particle is selected from 20 μm to 24 μm (non- limiting examples include any one or two of the following numerical values: 20 μm, 20.5 μm, 21 μm, 21.5 μm, 22 μm, 22.5 μm, 23 μm, 23.5 μm, 24 μm, etc.);

[0166] (td2) Dv90 of the graphitized particle is selected from 12 μm to 15 μm (non-limiting examples include any one or two of the following numerical ranges: 12 μm, 12.5 μm, 13 μm, 13.5 μm, 14 μm, 14.5 μm, 15 μm, etc.);

[0167] (td3) the Dv50 of the graphitized particle is selected from 5 μm to 7 μm (non- limiting examples include any one or two of the following numerical values: 5 μm, 5.2 μm, 5.4 μm, 5.5 μm, 5.6 μm, 5.8 μm, 6 μm, 6.2 μm, 6.4 μm, 6.5 μm, 6.6 μm, 6.8 μm, 7 μm, etc.); and

[0168] (td4) The Dv10 of the graphitized particle is selected from 2 μm to 3 μm (non- limiting examples are any one or two of the following numerical values: 2 μm, 2.1 μm, 2.2 μm, 2.3 μm, 2.4 μm, 2.5 μm, 2.6 μm, 2.7 μm, 2.8 μm, 2.9 μm, 3 μm, etc.).

[0169] By finely controlling the particle size and distribution of the graphitized particle within an appropriate range, it is more conducive to stably controlling the secondary negative electrode particle size and its distribution.

[0170] In some embodiments, the binder includes asphalt. Further, the binder may be mainly asphalt. Furthermore, in some embodiments, the binder is asphalt, which has good bonding effect and is not easy to introduce adverse impurities.

[0171] In some embodiments, the mass ratio of the binder to the plurality of graphitized particles is selected from 1:8.5 to 1:9.5, that is, selected from 1:(8.5-9.5). The mass ratio of the binder to the plurality of micro-particle carbons can also be selected from any of the following ratios or from an interval consisting of any two of the following ratios: 1:8.5, 1:8.6, 1:8.7, 1:8.8, 1:8.9, 1:9.0, 1:9.1, 1:9.2, 1:9.3, 1:9.4, 1:9.5, etc. Further, by controlling the amount of the binder (such as asphalt), the preset particle size and distribution of the secondary negative electrode particles can be better achieved.

[0172] In some embodiments, the secondary negative electrode particles are formed by agglomerating the plurality of graphitized particles and the binder.

[0173] In some embodiments of the present application, the surface of the secondary negative electrode particles comprises amorphous carbon. In some embodiments, the secondary negative electrode particle comprises a carbon-based core and an amorphous carbon layer located at least on a portion of the surface of the carbon-based core. It can be obtained by introducing an organic carbon material (asphalt) on the surface and then heat-treating it at a suitable temperature. The heat treatment may be performed above the melting point of the organic carbon material (such as asphalt) and below the graphitization temperature. Further, the heat treatment may be performed near the carbonization temperature (which may be slightly higher than the carbonization temperature). For example, the heat treatment may be performed at from about 1100 °C to about 1200 °C. The heat treatment time may be flexibly controlled according to the degree of conversion to amorphous carbon, for example, from about 4 hours to about 6 hours. After heat treatment, the surface-coated organic carbon material (asphalt) may be converted into amorphous carbon. Reference may also be made to the method for coating an amorphous carbon layer described in the second aspect of the present application.

[0174] In the present application, the aforementioned “carbon-based core” contains a negative electrode active material. In some non-limiting examples, the carbon-based core is composed of a negative electrode active material. It should be understood that the negative electrode active material of the carbon-based core contains carbon that enables active ions (such as lithium ions) to be embedded and extracted.

[0175] In some embodiments, the thickness of the amorphous carbon layer on the surface of the secondary negative electrode particles is less than about 500 nm. In some embodiments, the thickness of the amorphous carbon layer on the surface of the secondary negative electrodeparticles is selected from about 200 nm to about 500 nm. The thickness of the amorphous carbon layer on the surface of the secondary negative electrode particles may be selected from any one or two of the following intervals: 200 nm, 210 nm, 220 nm, 230 nm, 240 nm, 250 nm, 260 nm, 270 nm, 280 nm, 290 nm, 300 nm, 320 nm, 350 nm, 360 nm, 380 nm, 400 nm, 420 nm, 450 nm, 480 nm, 500 nm, etc.

[0176] In some embodiments, the mass content of the amorphous carbon layer in the secondary negative electrode particles is less than about 3.3 %. In some embodiments, the mass content of the amorphous carbon layer in the secondary negative electrode particles is selected from about 1.3 % to about 3.3 %. The mass content of the amorphous carbon layer in the secondary negative electrode particles may also be selected from any one of the following percentages or any two percentage intervals: 1.3 %, 1.4 %, 1.5 %, 1.6 %, 1.7 %, 1.8 %, 1.9 %, 2.0 %, 2.1 %, 2.2 %, 2.3 %, 2.4 %, 2.5 %, 2.6 %, 2.7 %, 2.8 %, 2.9 %, 3.0 %, 3.1 %, 3.2 %, 3.3 %, etc.

[0177] In some embodiments, the volume proportion of the amorphous carbon layer in the secondary negative electrode particles is less than about 3.3 %. In some embodiments, the volume proportion of the amorphous carbon layer in the secondary negative electrode particles is selected from about 1.3 % to about 3.3 %. The volume proportion of the amorphous carbon layer in the secondary negative electrode particles may also be selected from any one of the following percentages or any two percentage intervals: 1.3 %, 1.4 %, 1.5 %, 1.6 %, 1.7 %, 1.8 %, 1.9 %, 2.0 %, 2.1 %, 2.2 %, 2.3 %, 2.4 %, 2.5 %, 2.6 %, 2.7 %, 2.8 %, 2.9 %, 3.0 %, 3.1 %, 3.2 %, 3.3 %, etc.

[0178] In some embodiments, the surface of the single graphitized particle may also be coated with an amorphous carbon layer; the thickness of the amorphous carbon layer is ≤ 500 nm. In some embodiments, the thickness of the amorphous carbon layer on the surface of the single graphitized particle is selected at from about 200 nm to about 500 nm. The thickness of the amorphous carbon layer on the surface of the single graphitized particle may also be selected from any one or two of the following intervals: 200 nm, 210 nm, 220 nm, 230 nm, 240 nm, 250 nm, 260 nm, 270 nm, 280 nm, 290 nm, 300 nm, 320 nm, 350 nm, 360 nm, 380 nm, 400 nm, 420 nm, 450 nm, 480 nm, 500 nm, etc.

[0179] Further, in some embodiments, the mass content of the amorphous carbon layer in the single graphitized particle is ≤ 3.3%. In some embodiments, the mass content of the amorphous carbon layer in the single graphitized particle is selected to be from about 1.3 % to about 3.3 %. The mass content of the amorphous carbon layer in the single graphitized particle may also be selected from any one of the following percentages or any two percentageintervals: 1.3 %, 1.4 %, 1.5 %, 1.6 %, 1.7 %, 1.8 %, 1.9 %, 2.0 %, 2.1 %, 2.2 %, 2.3 %, 2.4 %, 2.5 %, 2.6 %, 2.7 %, 2.8 %, 2.9 %, 3.0 %, 3.1 %, 3.2 %, 3.3 %, etc.

[0180] Further, in some embodiments, the volume proportion of the amorphous carbon layer in the single graphitized particle is ≤ 3.3 %. In some embodiments, the volume proportion of the amorphous carbon layer in the single graphitized particle is selected to be from about 1.3 % to about 3.3 %. The volume proportion of the amorphous carbon layer in the single graphitized particle may also be selected from any one of the following percentages or any two percentages: 1.3 %, 1.4 %, 1.5 %, 1.6 %, 1.7 %, 1.8 %, 1.9 %, 2.0 %, 2.1 %, 2.2 %, 2.3 %, 2.4 %, 2.5 %, 2.6 %, 2.7 %, 2.8 %, 2.9 %, 3.0 %, 3.1 %, 3.2 %, 3.3 %, etc.

[0181] In some embodiments of the present application, the surface of at least a portion of the graphitized particles is coated with an amorphous carbon layer, and the thickness of the amorphous carbon layer, its mass content in the carbon-based particles, and its volume share in the graphitized particles can refer to the definition of the aforementioned amorphous carbon layer coated on the surface of secondary negative electrode particles or the surface of single graphitized particle.

[0182] In the present application, the confirmation of the amorphous carbon layer can be obtained by testing the conventional method of testing the crystal form of carbon materials in the art, such as Raman spectroscopy test and analysis, and the formation of the amorphous carbon layer can be analyzed based on the characteristic peak information of the carbon component in the spectrum (such as the intensity ratio of the D peak / G peak, ID / G ). Among them, the D peak and the G peak are both Raman characteristic peaks of the carbon atom crystal. The D peak represents the defects of the carbon atom crystal. The more defects there are, the greater the D peak intensity. The D peak intensity can reflect the content of the amorphous (turbostratified stacking) region, and the G peak represents the in-plane stretching vibration of the sp2hybridization of the carbon atom. The G peak intensity can reflect the content of the graphitized (layered structure) region; as the degree of disorder of the carbon atoms increases, the intensity ratio of the D peak to the G peak also increases. Whether an amorphous carbon layer is formed can be determined based on whether the ID / G (D peak / G peak intensity ratio) of the particle surface components before and after coating constitutes a statistically significant difference (e.g., p<0.05, p<0.01, etc.), that is, based on the degree of deviation between the turbostratic structure introduced after coating and the ID / G before coating, which is easy for those skilled in the art to judge. It is also possible to compare the difference between the Raman spectrum ID / G of the specific structural layer of the particle tobe tested and the standard Raman spectrum ID / G of graphite to determine whether it is an amorphous carbon layer.

[0183] It can also be determined whether an amorphous carbon layer is formed. The degree of graphitization can be tested by methods known in the art. The higher the degree of graphitization, the lower the degree of disorder. For example, the degree of graphitization can be tested using an X-ray diffractometer (such as Bruker D8 Discover). The test can refer to JIS K 0131-1996 and JB / T 4220-2011, measure the size of d 002 , and then calculate the degree of graphitization according to the formula G = (0.344-d 002 ) / (0.344-0.3354), where d 002 is the interlayer spacing in the artificial graphite crystal structure expressed in nanometers (nm).

[0184] In this application, the volume proportion of the “amorphous carbon layer” in the carbon-based particles (such as secondary carbon particles or single carbon particles) can be obtained by transmission electron microscopy (TEM) morphology observation combined with data analysis. The negative electrode sheet is cut, and a powder sample is scraped from the cross section. A TEM test is performed to compare the carbon-based particles coated with an amorphous carbon layer and those not coated with an amorphous carbon layer. An obvious interface can be observed on the surface of the carbon-based particles coated with an amorphous carbon layer, so that the thickness of the amorphous carbon layer at that position can be estimated from the TEM photo. The analysis can be performed from multiple different cross-sectional positions, and the average value is taken as the thickness of the amorphous carbon layer. Assuming that the carbon-based particles are spherical, based on the thickness of the amorphous carbon layer and the statistical data of the particle size of the carbon-based particles, the volume proportion of the amorphous carbon layer in the carbon-based particles can be estimated based on the volume of the carbon-based particles and the volume of the carbon-based core; further, based on the average mass of a single carbon-based particle, the volume of the carbon-based core (which can be calculated or obtained based on TEM test photos) and the density of the carbon-based core, the mass content of the amorphous carbon layer in the carbon-based particles can be estimated.

[0185] In some embodiments, the negative electrode active material of the primary negative electrode particles or the secondary negative electrode particles is graphite. By coating at least a portion of the surface of the secondary negative electrode particles with amorphous carbon, the fast-charging performance of the battery may be improved. In addition, coating at least a portion of the surface of the single graphitized particles with amorphous carbon may also improve the fast-charging performance of the battery. By reasonably controlling thecontent of amorphous carbon, the fast-charging performance of the battery may be improved while ensuring good battery cycle performance.

[0186] However, when amorphous carbon is coated on the surface of secondary negative electrode particles for example, as the proportion of secondary carbon particles increases, the cycle life of the battery cell may decrease. This may be due to the high surface activity of amorphous carbon relative to the surface activity of the carbon-based core (such as graphite), which may reduce the stability of the negative electrode during the cycle; at this time, the mass ratio of secondary carbon particles in the carbon-based particles may be reasonably controlled (such as controlled at 30 % to 50 %, and any suitable mass ratio described above can also be referred to), so as to better balance the needs for gas production removal, capacity, and battery cycle stability, while achieving low tortuosity and high capacity retention rate.

[0187] In some embodiments, the negative electrode film layer may further include a binder. The binder may be selected from one or more of styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA) and carboxymethyl chitosan (CMCS).

[0188] In some embodiments, the negative electrode film layer may further include a conductive agent, which may be selected from one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.

[0189] In some embodiments, the negative electrode film layer may optionally include other additives, such as a thickener (e.g., sodium carboxymethyl cellulose (CMC-Na)).

[0190] In some embodiments, the negative electrode sheet may be prepared in the following manner: the components for preparing the negative electrode sheet, such as the negative electrode active material, the conductive agent, the binder, and any other components are dispersed in a solvent (such as deionized water) to form a negative electrode slurry; the negative electrode slurry is coated on at least one side surface of the negative electrode collector (it can be on a single surface or on two surfaces), and after drying, compacting (cold pressing can be used), etc., the negative electrode sheet can be obtained.

[0191] In embodiments, primary negative electrode particles and secondary negative electrode particles are prepared using the carbonization and graphitization steps discussed above. Non-graphite carbon may be carbonized at relatively low temperature conditions (such as 1100 ± 50 °C), and the carbon particles shrink and the structure becomes more compact. Non-graphite (such as carbon obtained after carbonization) may be graphitized, and thehexagonal carbon atom plane network is transformed from a disordered arrangement into two- dimensional space (such as a chaotic layer structure or amorphous carbon) to an ordered arrangement of graphite structure in three-dimensional space.

[0192] In some embodiments, a coating step is added. The coating step comprises the following steps: mixing the material with an organic carbon material (such as petroleum pitch, lignin, starch, or asphalt) in a certain mass ratio, and heating at a suitable temperature (insulation temperature, such as from about 1100 °C to about 1200 °C, further such as 1150 °C) to prepare secondary particles comprising a coating layer. In some embodiments, the heating time (insulation time) is from about 12 hours to 24 hours (such as about 12 hours, 15 hours, 16 hours, 18 hours, 20 hours, etc., also such as from about 12 hours to about 16 hours). In some embodiments, the coating is carried out under inert gas conditions. In some embodiments, the coating layer in the secondary particles comprising the coating layer contains amorphous carbon. In some non-limiting examples, before the heat preservation step of coating, the temperature can be raised to a preset temperature at a heating rate of, for example, from about 1 °C / min to about 10 °C / min, and then the temperature can be kept warm. Non-limiting examples of the heating rate are 1 °C / min, 1.3 °C / min, 1.4 °C / min, 1.5 °C / min, 1.6 °C / min, 1.8 °C / min, 2 °C / min, 3 °C / min, 4 °C / min, 5 °C / min, 6 °C / min, 8 °C / min, 10 °C / min, etc. In some non-limiting examples, the heating rate from room temperature (such as from about 20 °C to about 30 °C, further such as 25 °C) to a preset temperature (such as from about 1100 °C to about 1200 °C) may be from about 1.3 °C / min to about 2.5 °C / min, and further such as from about 1.5 °C / min to about 1.8 °C / min. In some embodiments, in the coating step, after the material is mixed with the organic carbon material (such as asphalt), it may also be preheated at a relatively low temperature (such as from about 500 °C to about 600 °C) to fully melt the organic carbon material (such as asphalt), and then heated to a preset temperature (such as from about 1100 °C to about 1200 °C, further such as about 1150 °C) for carbonization. The temperature may be raised to a preset temperature at a heating rate of from about 1 °C / min to about 5 °C / min (further such as from about 1.3 °C / min to about 2 °C / min) and then preheated (from about 500 °C to about 600 °C insulation), and non-limiting examples of the heating rate are 1 °C / min, 1.5 °C / min, 2 °C / min, 2.5 °C / min, 3 °C / min, 3.5 °C / min, 4 °C / min, 4.5 °C / min, 5 °C / min, etc. It should also be noted that when coating the amorphous carbon layer, the heating rate needs to be reasonably controlled. If the heating rate is too fast, it will easily lead to more defects in the coating layer carbon. When there are more defects on the surface of the carbon particles, it will be detrimental to the battery cycle performance.

[0193] In some embodiments, the organic carbon material may include one or more of asphalt, phenolic resin, furfural resin, and epoxy resin. In some embodiments, the organic carbon material includes asphalt.

[0194] In the step of coating the amorphous carbon layer on the surface of the material, the mass of the organic carbon material (such as asphalt) accounts for the total mass of the material and the organic carbon material (such as asphalt). The proportion of the mass of the amorphous carbon layer in the secondary particulate carbon in the first aspect mentioned above can refer to the mass proportion of the amorphous carbon layer in the secondary particulate carbon in the first aspect. In some embodiments, the mass of the organic carbon material (such as asphalt) accounts for ≤ 3.3 % of the total mass of the material and the organic carbon material (such as asphalt), and can further be from about 1.3 % to about 3.3 %, and can also be selected from any of the following percentages or any two percentage intervals: 1.3 %, 1.4 %, 1.5 %, 1.6 %, 1.7 %, 1.8 %, 1.9 %, 2.0 %, 2.1 %, 2.2 %, 2.3 %, 2.4 %, 2.5 %, 2.6 %, 2.7 %, 2.8 %, 2.9 %, 3.0 %, 3.1 %, 3.2 %, 3.3 %, etc.

[0195] In the present application, when preparing primary negative electrode particles and secondary negative electrode particles, the “inert gas” involved can be used as long as it can avoid side reactions of the gas, including oxygen-free conditions to avoid oxidation of chemical components in the petroleum pitch under high temperature conditions. In some non-limiting examples, the inert gas includes one or more of nitrogen, helium, argon, neon, etc. In some non-limiting examples, the inert gas includes nitrogen. In some embodiments, each occurrence of the inert gas condition is independently a nitrogen condition.

[0196] By controlling the relevant parameters of the carbonization, graphitization, granulation, coating and other steps, and the coordination between the parameters, the compounding of primary negative electrode particles and secondary negative electrode particles may be better controlled, so that the tortuosity can be controlled within a more appropriate range, which is conducive to gas production and discharge while maintaining good battery cell cycle performance and extending battery life. For example, in the process of coating amorphous carbon on the surface of secondary negative electrode particles, the amount of amorphous carbon coating may be better controlled by controlling the amount of organic carbon material (such as asphalt) and the temperature curve, thereby improving the fast- charging performance of the battery while maintaining good cycle performance.

[0197] In some embodiments, the graphitized particle is prepared by a method comprising the following steps in sequence: crushing the carbon source such as petroleum pitch, grinding, carbonizing at 1050 °C. to 1150 °C, graphitizing at a temperature above 2800 °C, and screeningto obtain the single particle carbon. Before carbonizing the graded material, a mixing step may be added to obtain a material with a preset particle size and distribution.

[0198] In some embodiments, the steps of preparing graphitized particle include crushing and classifying the carbon source such as raw coke materials, further such as petroleum coke, → mixing → carbonization → graphitization.

[0199] In the process of preparing single graphitized graphite, the temperature and time conditions of the carbonization and graphitization may be selected from any suitable temperature conditions mentioned above independently or in combination.

[0200] In some embodiments, the secondary negative electrode particles are prepared by a method comprising the following steps in sequence: preparing a micro-particle carbon, mixing the micro-particle carbon and the binder, granulating at a temperature from about 500 °C to about 600 °C, carbonizing at a temperature from about 1050 °C to about 1150 °C, graphitizing at a temperature above 2800°C, optionally coating at a temperature from about 1100 °C to about 1200 °C, and screening to obtain the secondary negative electrode particles.

[0201] In some embodiments, the steps of preparing secondary negative electrode particles include crushing and grinding the carbon source such as petroleum pitch, or raw coke raw materials, further such as petroleum coke, → mixing (mixing raw materials and binders (such as asphalt)) → granulation (low-temperature heat treatment) → crushing (deagglomerating agglomerated particles) → carbonization → graphitization → coating with an amorphous carbon layer (optional step).

[0202] In the process of preparing secondary negative electrode particles, the temperature and time conditions of granulation, carbonization, graphitization and coating can be selected from any suitable temperature conditions mentioned above independently or in combination in any suitable manner.

[0203] Below, some embodiments of the present application are described. The embodiments described below are exemplary, are only used to explain the present application, and cannot be construed as limiting the present application. In the embodiments, if the technology or conditions are not specified, they are carried out according to the description above, or according to the technology or conditions described in the document in this area or according to the product specification. The reagents used or the instruments that do not specify the manufacturer are conventional products that can be obtained commercially or can be synthesized in a conventional manner by commercially available products.Preparation of Secondary Battery:

[0204] An embodiment of the present application provides a method for preparing a secondary battery, comprising the step of fabricating a negative electrode plate using the artificial graphite described in the first aspect of the present application.

[0205] In certain embodiments, the preparation of the negative electrode plate includes dispersing the negative active material—comprising the artificial graphite—with a binder, and optionally a thickener and a conductive agent, in a solvent such as deionized water to form a uniform negative electrode slurry. The slurry is then coated onto at least one surface of a negative electrode current collector, followed by drying, cold pressing, and other processing steps to obtain the negative electrode plate.

[0206] The method may further include preparing a positive electrode plate. In some embodiments, a positive active material, a conductive agent, and a binder are dispersed in a solvent, such as N-methylpyrrolidone (NMP), to form a uniform positive electrode slurry. This slurry is coated onto a positive electrode current collector and subsequently dried, cold pressed, and processed to yield the positive electrode plate.

[0207] The secondary battery is assembled by combining the negative electrode plate, the positive electrode plate, and an electrolyte. In certain embodiments, the positive electrode plate, separator, and negative electrode plate are arranged in sequence—either by winding or lamination—such that the separator is positioned between the electrodes to provide electrical isolation. The resulting electrode assembly is placed into an outer casing, followed by electrolyte injection and sealing to complete the secondary battery.

[0208] The present application does not impose limitations on the shape of the secondary battery, which may be cylindrical, prismatic (square), or any other suitable geometry.

[0209] In some embodiments, the secondary battery may be integrated into a battery module. The module may contain multiple secondary batteries, with the quantity adjustable based on the intended application and required capacity. A battery module in which multiple secondary batteries are arranged along the module’s longitudinal axis, although other configurations are also contemplated. The batteries may be secured using fasteners and housed within a casing that provides a receiving space for the battery array.

[0210] Furthermore, the battery module may be incorporated into a battery pack. The number of modules within the pack may be varied according to application-specific requirements. A battery pack comprising a battery case with an upper and lower housing. The upper housing encloses the lower housing to form a sealed compartment for accommodating multiple battery modules, which may be arranged in any suitable configuration.Application of finished battery:

[0211] A third aspect of the present application provides an apparatus comprising the secondary battery described in the second aspect. The secondary battery serves as the power source for the apparatus, thereby imparting the performance benefits associated with the battery, including fast charging, enhanced energy density and cycle life.

[0212] The apparatus may include, but is not limited to, mobile electronic devices (e.g., smartphones, tablet computers, laptops), electric vehicles (e.g., battery electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, scooters, golf carts, trucks), electric trains, marine vessels, satellites, and energy storage systems.

[0213] The apparatus may incorporate the secondary battery, battery module, or battery pack described herein, selected according to its specific power and energy requirements. An apparatus such as an electric vehicle, which may utilize a battery module or pack to meet high power and energy density demands. Alternatively, the apparatus may be a compact consumer device, such as a mobile phone or laptop, where the secondary battery provides a lightweight and efficient power source. Example Embodiments

[0214] Embodiment 1. A method of fabricating a negative electrode comprising: grinding a petroleum pitch at a temperature below a softening point of the petroleum pitch to form at least pitch particles; stabilizing the pitch particles by heating to a stabilizing temperature from about 100 ^C to about 400 ^C; carbonizing the pitch particles by heating to a temperature from about 700 ^C to about 1800 ^C to form at least calcined particles; and graphitizing by heating to a graphitization temperature of about 2000 ^C to about 4000 ^C.

[0215] Embodiment 2. The method of Embodiment 1, further comprising granulating the pitch particles by heating to a temperature from about 200 ^C to about 600 ^C and deagglomerating agglomerated particles, wherein granulating further comprises using a binder, wherein the binder is a thermally and chemically untreated petroleum pitch.

[0216] Embodiment 3. The method of Embodiment 1 or Embodiment 2, wherein granulating further comprises using a binder, wherein at least one binder is selected from the group of binders consisting of asphalt, phenolic resin, furfural resin, epoxy resin, lignin, starch, and any combination thereof.

[0217] Embodiment 4. The method of any one of the preceding Embodiments, wherein granulating further comprises using a binder comprising a graphitization catalyst.

[0218] Embodiment 5. The method of any one of the preceding Embodiments, wherein stabilizing the pitch particles by heating to a stabilizing temperature from about 150 ^C to about 400 ^C.

[0219] Embodiment 6. The method of any one of the preceding Embodiments, wherein a ramp rate for increasing a temperature of the pitch particles to the stabilizing temperature is from about 0.5 ^C per minute to about 10 ^C per minute.

[0220] Embodiment 7. The method of any one of the preceding Embodiments, wherein a ramp rate for increasing a temperature of the pitch particles to the stabilizing temperature is from about 3 ^C per minute to about 10 ^C per minute in air.

[0221] Embodiment 8. The method of any one of the preceding Embodiments, wherein the grinded pitch particles have a particle size ranging from about 1 micron to about 25 microns.

[0222] Embodiment 9. The method of any one of the preceding Embodiments, wherein the grinded pitch particles have a particle size ranging from about 5 micron to about 10 microns.

[0223] Embodiment 10. The method of any one of the preceding Embodiments, wherein the pitch particles are held at the stabilizing temperature for a period of about 10 minutes to about 6 hours.

[0224] Embodiment 11. The method of any one of the preceding Embodiments, wherein the carbonizing is performed in an environment comprising about 0.1 mol% oxygen or below at a temperature of 1200 ^C for 8 hours.

[0225] Embodiment 12. The method of any one of the preceding Embodiments, wherein the graphitization is performed in an environment comprising about 0.1 mol% oxygen or below at a temperature of 3000 ^C for 2 hours.

[0226] Embodiment 13. The method of any one of the preceding Embodiments, wherein granulating the pitch particles is performed after the carbonizing the pitch particles.

[0227] Embodiment 14. The method of any one of the preceding Embodiments, further comprising de-agglomerating the carbonized pitch particles.

[0228] Embodiment 15. The method of any one of the preceding Embodiments, wherein the graphitized particles have a degree of graphitization of about 90% or more.

[0229] Embodiment 16. The method of any one of the preceding Embodiments, wherein the graphitized particles comprise primary negative electrode particles.

[0230] Embodiment 17. The method of any one of the preceding Embodiments, wherein the graphitized particles comprise secondary negative electrode particles.

[0231] Embodiment 18. A composition for negative electrodes comprising: from about 2 to about 100 % of secondary graphitic particles; wherein the secondary graphitic particles havea degree of graphitization of about 80% or more and a specific surface area of about 0.1 m2 / g to about 6 m2 / g; wherein the secondary graphitic particles comprise microparticle active material produced from mesophase pitch or needle coke or petroleum coke or blends of them; and wherein the secondary graphitic particles are granulated using a binder, wherein at least one binder is selected from the group of binders consisting of petroleum pitch, asphalt, phenolic resin, furfural resin, epoxy resin, lignin, starch, and any combination.

[0232] Embodiment 19. The composition of Embodiment 18, wherein the at least one binder comprises a graphitization catalyst.

[0233] Embodiment 20. The composition of Embodiment 18 or Embodiment 19, wherein the composition comprises primary negative electrode particles, wherein the primary negative electrode particles comprise mesophase pitch based graphite, needle coke-based graphite, petroleum coke-based graphite, graphitization catalyst, or any combination thereof.

[0234] Embodiment 21. The composition of any one of Embodiments 18-20, wherein only one of the secondary negative electrode particles, the primary negative electrode particles, and the binder comprises the graphitization catalyst.

[0235] Embodiment 22. The composition of any one of Embodiments 18-21, wherein the at least one binder is petroleum pitch, mesophase pitch, isotropic pitch, or any combination thereof t.

[0236] Embodiment 23. The composition of any one of Embodiments 18-22, wherein the secondary negative electrode particles and the binder comprise a graphitization catalyst.

[0237] Embodiment 24. An electrode produced from the composition of any one of Embodiments 18 to 23.

[0238] Embodiment 25. A battery comprising the electrode of Embodiment 24.

[0239] To facilitate a better understanding of the present invention, the following examples of certain aspects of some embodiments are given. In no way should the following examples be read to limit, or define, the entire scope of the disclosure. EXAMPLES

[0240] In the following examples, “room temperature” refers to a temperature from about 20 °C to about 30 °C, and “wt%” refers to weight percentage.

[0241] In the following examples, unless otherwise specified, the “inert gas condition” refers to a nitrogen gas condition. Preparation of artificial graphite active materials:

[0242] In the present application, when preparing single graphitized particle, the heating program is involved. If not specifically limited, the heating rate may be selected from about0.5 °C / min to about 15 °C / min. When it comes to the cooling program, if not specifically limited, the temperature may be cooled by furnace cooling or the like. For example, the heating rate before carbonization may be from about 1 °C / min to about 10 °C / min, and the heating rate before graphitization may be from about 1 °C / min to about 15 °C / min.

[0243] In the process of preparing secondary negative electrode particles, a heating program is involved. If not specifically limited, the heating rate may be from about 0.5 °C / min to about 15 °C / min. When a cooling program is involved, if not specifically limited, the temperature may be cooled by furnace cooling or the like. For example, the heating rate before bonding granulation may be from about 1 °C / min to about 5 °C / min, the heating rate before carbonization may be from about 1 °C / min to about 10 °C / min, the heating rate before graphitization may be from about 1 °C / min to about 15 °C / min, and the heating rate before coating amorphous carbon may be from about 1 °C / min to about 10 °C / min. If a preheating program (such as from about 500 to about 600 °C) is set before coating, a heating rate from about 1 °C / min to about 5 °C / min may be used.

[0244] In the following preparation examples, unless otherwise specified, when performing bonded granulation, the heating rate from room temperature to the preset temperature (from about 500 °C to about 600 °C) is from about 1.3 °C / min to about 2.4 °C / min, which may take from about 4 hours to about 6 hours; when performing carbonization, the heating rate from room temperature to the preset temperature (about 1100 °C) is from about 1.5 °C / min to about 1.8 °C / min, which may take from about 10 hours to about 12 hours; when performing graphitization, the heating rate from room temperature to the preset temperature (about 3000 °C) is from about 1.5 °C / min to about 2°C / min; when coating amorphous carbon, the heating rate from room temperature to the preset temperature (about 1150 °C) is from about 1.5 °C / min to about 1.8 °C / min. Example 1

[0245] Example secondary negative electrode particles were produced from petroleum pitch and needle coke. The needle coke used in these experiments comprises from about 4.7 wt. % to about 5.5 wt % volatiles, from about 0.27 wt % to about 0.30 wt % sulfur, from about 0.03 wt. % to about 0.17 wt. % ash, from about 0.20 wt. % to about 0.27 wt % nitrogen, from about 52 to about 77 HGI, and no water.

[0246] The secondary negative electrode particles prepared from petroleum pitch used a conventional process, which includes a grinding step, a stabilizing step, a granulation step, a carbonization step, a de-agglomeration step, and a graphitization step. Additional secondary negative electrode particles were prepared from petroleum pitch with modified heat treatmentin the stabilizing step according to embodiments of the present disclosure. The secondary negative electrode particles prepared from needle coke also used a conventional process, which included a grinding step, a granulating step, a carbonization step, a de-agglomeration step, and a graphitization step.

[0247] Petroleum Pitch: The petroleum pitch used to produce the secondary particles has a softening point from about 250 ^C to about 450 ^C, and a mesophase content from about 50 % to about 100 %.

[0248] Conventional Pitch Processing: the method steps to prepare primary negative electrode particles includes crushing, optionally stabilization / oxidation, optionally coating, carbonization, graphitization, optionally coating again, and screening.

[0249] The raw petroleum pitch optionally comprising a graphitization catalyst and optionally a petroleum coke or needle coke is crushed and classified under a mechanical mill (impact mill equipment), and Dv10, Dv50 and Dv99 are monitored and controlled at a relatively large preset size, and the particle size distribution reaches a preset distribution range, and then enters the carbonization process.

[0250] The particles produced may be subjected to a stabilization / oxidation process by heat treating the particles at temperatures from about 100 ^C to about 400 ^C for about 5 minutes to about 24 hours in an oxygen rich environment to produce stabilized particle. The oxygen rich environment may be defined as 20 % oxygen content or higher. For Example 1, the produced particles were heated at 0.5 ^C per minute up to 250 ^C, and the heat was maintained at 250 ^C for 2 hours under air flow.

[0251] The secondary negative electrode particles of above are prepared fully mixed with asphalt or petroleum pitch or lignin or furfural resin or phenolic resin or epoxy or starch in a certain mass ratio, and heated in an inert gas environment at 1150 °C.

[0252] Carbonization is performed by heat treatment at 1100 °C in an inert gas environment for 48 hours (including the heating time from room temperature with a heating ramp rate from about 1 ^C to about 4 ^C depending upon the temperature range) to further expel volatiles, shrink and densify the particles, which is beneficial to improving material strength and increasing the subsequent graphitization bulk density. For Example 1, the heating ramp rate was 4 ^C per minute from room temperature to about 200 ^C, then 2 ^C per minute from about 200 ^C to about 800 ^C, then 1 ^C per minute from about 800 ^C to about 1100 ^C, and the temperature was then maintained at 1100 ^C for 20 hours.

[0253] After the carbonization step, the graphitization treatment is directly carried out inan inert gas environment at 3000 °C for 72 hours (including the heating time from room temperature to about 3000 ^C at a heating ramp rate of 10 ^C per minute.

[0254] The optional coating step is performed by mixing the graphitized particles of above with asphalt or petroleum pitch or lignin or furfural resin or phenolic resin or epoxy or starch in a certain mass ratio, and heated in an inert gas environment at 1150 °C. However, the coating step may be done before or after graphitization.

[0255] The material obtained is screened and demagnetized to obtain single-grain graphitized particle with a preset particle size requirement. In this example, the particle sizes of the prepared single-grain graphitized particle are as follows: Dv 10 is 6.3 microns, Dv 50 is 13.5 microns, and Dv99 is 40.5 microns.

[0256] The secondary negative electrode particles may also be prepared by grinding the carbon source such as petroleum pitch or raw material, granulation, oxidation (optional), carbonization, graphitization, coating (optional), and screening.

[0257] The carbon source comprising petroleum pitch with optionally a graphitization catalyst or a petroleum coke or a needle coke, is crushed under a mechanical mill using a fluidized bed jet mill or an impact mill for up to 8 hours, for example. The crushed carbon source is then selected according to its particle size distribution to reach a pre-selected distribution range of Dv10, Dv50, Dv90 and Dv99. The particle sizes of the prepared micro- particle graphite are: Dv10 is 2 to 3 microns, Dv50 is 5 to 10 microns, Dv90 is 12 to 15 microns, and Dv99 is 20 to 24 microns. The crushed carbon source with a selected particle size distribution then enters the bonding granulation process.

[0258] The granulation step is performed under inert gas conditions. The dispersed carbon source particles prepared in step (1) are mixed with a binder: preferably a petroleum pitch or asphalt, or epoxy resin or phenolic resin or lignin and optionally containing up to 5% graphitization catalyst in a mass ratio of 9:1. The temperature is raised to 200 °C to 600 °C for heat treatment for about 4 hours to about 6 hours. In preferred embodiments, the temperature is raised 30 ^C above the softening temperature. The particle size is controlled by adjusting the temperature rise curve, and Dv10, Dv50 and Dv99 are monitored and controlled within the preset size. The agglomerated particles are crushed using a powder deagglomeration machine to deagglomerate the agglomerated particles.

[0259] The optional oxidation step is performed by subjecting the produced particles to an oxidation process by heat treating the particles at temperatures from about 100 ^C to about 400 ^C, such as lower than 280 ^C for example, for about 5 minutes to about 24 hours, such as 3 hours for example, in an oxygen rich environment or air to produce stabilized particles. Thepitch particles may then be agglomerated through a process that includes a laboratory mixer to produce pitch particles having a Dv50 of 10-15 microns, for example. For Example 1, the produced particles were heated at 0.5 ^C per minute up to 250 ^C, and the heat was maintained at 250 ^C for 2 hours under air flow.

[0260] The carbonization process is performed after the low-temperature heat treatment in step (2). The heat treatment is carried out in an inert gas environment at 1100 °C or 1200 °C for about 48 hours (including the heating time from room temperature) to further expel volatiles, further shrink and densify, which is beneficial to improving material strength and increasing the subsequent graphitization bulk density. The heat treatment may be carried out under nitrogen flow at 1200 °C for 2 hours, for example.

[0261] After the carbonization process, the carbonized particles were then de-agglomerated through a process that included hammer or jaw milling / crushing.

[0262] The graphitization process is then performed by directly carrying out in an inert gas environment, such as under argon flow, at 3000 °C (from about 2800 °C to about 3400 °C) for up to 2 hours in an Acheson type furnace or a Castner furnace or a continuous furnace to obtain graphitized secondary particles.

[0263] Optionally, a coating deposition may be performed after the graphitization process. The graphitized particles of above are mixed with asphalt or petroleum pitch or lignin or furfural resin or phenolic resin or epoxy or starch in a certain mass ratio, and heated in an inert gas environment at about 1150 °C.

[0264] Screening is then performed after the graphitization process or the coating deposition. The resulting material needs to be screened to remove magnetic species and obtain secondary negative electrode particles that meet the preset particle size requirements mentioned above. In this example, the particle sizes of the prepared secondary negative electrode particles are as follows: Dv10 is 4.5 microns, Dv50 is 10.5 microns, and Dv99 is 34 microns with a 2 microns uncertainty.

[0265] The physical characteristics of the resultant secondary negative electrode particles were determined as shown below in Table 1.Table 1 Precursor Petroleum Pitch Petroleum Needle Coke Pitch s.

[0266] Additional graphitic particles were produced from petroleum pitch. Samples of primary negative electrode particles and secondary negative electrode particles were produced by modifying the processing. In general, the graphitized particles were produced in a process that included a grinding step, a stabilizing step, an agglomeration step, a carbonization step, a de-agglomeration step, and a graphitization step.

[0267] Petroleum Pitch: The petroleum pitch used to produce the secondary negative electrode particles has a softening point from about 250 ^C to about 450 ^C, and a mesophase content from about 50 % to about 100 %.

[0268] Primary Negative Electrode Particles Production:

[0269] The carbon source for primary negative electrode particles and secondary negative electrode particles may be a mixture of petroleum pitch with optional graphitization catalyst and raw coke material. In some embodiments, the raw coke material may include one or more of raw petroleum coke, raw asphalt coke, metallurgical coke, for example. In some preferred examples, the raw coke material includes raw petroleum coke. In some embodiments, the raw coke material is needle coke. The needle coke may include one or more of needle raw petroleum coke and needle raw coal tar coke. In some preferred examples, the needle coke includes needle petroleum coke.

[0270] The carbon source may be crushed and classified under a mechanical mill (impact mill equipment). The Dv10, Dv50 and Dv99 are monitored and controlled at a relatively largepreset size, and the particle size distribution reaches a preset distribution range, and then enters the carbonization process.

[0271] Then, an optional oxidation step may be followed. The crushed and classified particles may be subjected to a stabilization / oxidation process by heat treating the particles at temperatures between about 100 ^C to about 400 ^C for about 5 minutes to about 24 hours in an oxygen rich environment to produce stabilized particle. For Example 2, the produced particles were heated at 0.5 ^C per minute up to 300 ^C, and the heat was maintained at 300 ^C for 6 hours under air flow.

[0272] An optional coating step may follow. The particles above are mixed with a binder, wherein the binder comprises asphalt or petroleum pitch or lignin or furfural resin or phenolic resin or epoxy or starch in a certain mass ratio. For Example 2, the binder represented from about 7 wt.% to about 8 wt.% of the total weight of the mixture of particles and binder.

[0273] A carbonization step is then performed. Heat treatment is performed at 1150 °C in an inert gas environment for 48 hours (including the heating time from room temperature to 1150 °C at a heating ramp rate of 10 °C per minute for Example 2) to further expel volatiles, further shrink and densify, which is beneficial to improving material strength and increasing the subsequent graphitization bulk density.

[0274] After the carbonization, a graphitization treatment is directly carried out in an inert gas environment at 3000 °C (at least greater than 2800°C) for 72 hours (including the heating time from room temperature to 3000 °C at a heating ramp rate of 10 °C per minute for Example 2).

[0275] An optional coating step may follow. The graphitized particles of above are mixed with asphalt or petroleum pitch or lignin or furfural resin or phenolic resin or epoxy or starch in a certain mass ratio, and heated in an inert gas environment at 1150 °C.

[0276] The resulting material is then screened and demagnetized to obtain single-grain graphite with a preset particle size requirement. In Example 2, the particle sizes of the prepared single-grain graphitized particle are as follows: Dv10 is 6.3 microns, Dv50 is 13.5 microns, and Dv99 is 40.5 microns.

[0277] Preparation of Secondary Negative Electrode Particles:

[0278] While the first step of the primary negative electrode particles is a single grinding step to particles sizes from about 10 µm to about 15 µm, the obtention of petroleum pitch particles to the target size is performed in two steps for the secondary negative electrode particles as the pitch particles are crushed to particles sizes smaller than the target size (here 10µm) and then an agglomeration step is added to obtain particles sizes from about 10 µm to about 15 µm.

[0279] The first step is grinding and classification of the raw material. Petroleum pitch optionally comprises a graphitization catalyst (such as boron or boron like compounds for example) or a petroleum coke or needle coke is crushed and classified under a mechanical mill (impact mill equipment), and the particle size distribution is made to reach a preset distribution range of Dv10, Dv50, Dv90 and Dv99 are monitored and controlled within the preset size to obtain primary negative electrode particles, which then enter the bonding granulation process. The particle sizes of the prepared micro-particle graphite are Dv10 is 2 to 3 microns, Dv50 is 5 to 7 microns, Dv50 is 12 to 15 microns, and Dv99 is 20 to 24 microns.

[0280] For Example 2, the softening point of the petroleum pitch was 280 ^C. Therefore, it was heated to 300 ^C. Table 2 summarizes the physical characteristics of the additional graphitic particles prepared in Example 2. Table 2: Summary of the Physical Characteristics of Graphitic Particles Target Processing Heat Particle Size SpecificCharacterization of amorphous carbon:

[0281] The intensity ratio of the D peak / G peak of graphite (ID / G) is analyzed by Raman spectroscopy, and the degree of deviation of the ID / G of the surface layer of the carbon-basedparticles before and after the amorphous carbon layer is coated is tested to determine whether there is an amorphous layer on the surface of the carbon-based particles to be tested. After the amorphous carbon layer is formed, the ID / G changes significantly in a statistical sense (p<0.01), and those skilled in the art can make an accurate judgment on whether an amorphous carbon layer is formed. ID / IG represents the ratio of the peak intensity ID of the peak D to the peak intensity IGof the peak G. The peak D and peak G are the Raman characteristic peaks of graphite materials. The peak D and peak G of the artificial graphite can be measured by laser Raman spectroscopy, such as Advantage 785™ Raman spectrometer. In the Raman spectrum of the artificial graphite of the present application measured by a Raman spectrometer, the peak D is at the position of 1300 cm−1to 1400 cm−1, and the peak G is at the position of 1580 cm−1to 1620 cm−1.

[0282] As described above, in thespectrum of graphite, the D peak intensity can reflect the content of the amorphous (turbostratic stacking) region, and the G peak intensity can reflect the content of the graphitized (layered structure) region.

[0283] The specific surface area (SSA) of the artificial graphite can be measured using a method known in the art. For example, according to GB / T 19587-2017 (Determination of the specific surface area of solids by gas adsorption using the BET method), analysis of the specific surface area by the nitrogen adsorption can be used, and the specific surface area can be calculated by the BET (Brunauer Emmett Teller) method, in which the analysis of the specific surface area by the nitrogen adsorption can be carried out by a specific surface and pore size distribution analyzer (Type: Tri Star II 3020) from Micromeritics, USA.

[0284] The tap density of the artificial graphite can be measured using a method known in the art. For example, refer to the standard GB / T 5162-2006 and use a powder tap density tester (such as Bettersize BT-301, Dandong, China) to test.

[0285] The powder compaction density of the artificial graphite can be tested by a method known in the art. For example, refer to GB / T 24533-2009 and use an electronic pressure testing machine (such as UTM7305) to test: put a certain amount of powder on a special compaction mold, set different pressures, and read the thickness of the powder under different pressures on the equipment, and calculate the compaction density under different pressures. In the GB / T 24533-2009, the machine used for the measurement of the powder compaction density has a shim with a diameter of 13 mm, a top post with a diameter of 13 mm, and a metal cylindrical sleeve with an inner diameter of 13 mm.

[0286] The graphitization degree of the artificial graphite can be measured with a well- known method in the art. For example, the graphitization degree of the artificial graphite canbe measured using an X-ray diffractometer (Bruker D8 Discover). The test can refer to JIS K 0131-1996, JB / T 4220-2011: measuring the size of d002, and then calculating the graphitization degree according to the formula G=(0.344−d002) / (0.344−0.3354)×100%, in which d002 is the interlayer spacing in the artificial graphite crystal structure, in nm.

[0287] The following peaks using X-Ray Diffraction (XRD) were used to quantify the characteristics of the primary negative electrode particles and secondary negative electrode particles through peak ratios as follows: d 002 from X-Ray Diffraction (0.3354 to 0.340 nm), Lc (100 -5000 nm), DoG (50 - 100 % defined by DoG = (0.344- d 002 ) / (0.344-0.3354), La (5- 5000 nm), d 002 / I110 ratio (10-1000), I004 / I110 ratio (0.1-100). To determine the d-spacing values, the powder XRD pattern of each sample was obtained, and the d 002 -peak of graphite was further analyzed. Powder XRD was performed using CuK-^ radiation having a wavelength of 1.5406Å. The d 002 -peak of graphite is located at a 2^ value of approximately 26°, where ^ is the X-ray scattering angle. Based on the 2^ peak position of the d 002 -peak, the Bragg equation (^=2 d 002 *sin^) was used to calculate the interplanar d-spacing values (d 002 ). La and Lc represent the crystal size, both length and thickness, and are determined from the width of the different XRD peaks.

[0288] When an artificial graphite with an appropriate OI value is used for the electrode plate, it can have a higher degree of isotropy, so that the expansion of the artificial graphite in the electrode plate is dispersed in all directions during the lithium intercalation, which can further reduce the cyclic expansion of electrode plates and batteries. At the same time, the artificial graphite has a higher binding force with a negative electrode current collector, which can further reduce the cyclic expansion of electrode plates and the batteries. In addition, since the electrode plate using the artificial graphite can also have a higher compacted density, the battery can obtain a higher energy density.

[0289] In the present application, an orientation index of an artificial graphite is defined as OI=I004 / I110 in which in the X-ray diffraction analysis of the artificial graphite, the peak area of the diffraction peak attributed to 004 crystal plane of the artificial graphite is I004, and the peak area of the diffraction peak attributed to 110 crystal plane of the artificial graphite is I110. The X-ray diffraction analysis can be carried out according to standard JISK 0131-1996, and an X-ray diffractometer (such as Bruker D8 Discover X-ray diffractometer) is used for testing. In the X-ray diffraction analysis test, a copper target can be used as an anode target, CuKβ rays are filtered by a Ni filter with a thickness of 0.02 mm, and CuKα rays are used as a radiation source, with the ray wavelength λ=1.5418 Å (taken the weight average of Kα1 and Kα2), the scanning 2θ angle range of 20° to 80°, and the scanning rate of 4° / min.

[0290] The 2θ angle corresponding to 004 crystal plane of artificial graphite is from 53.5° to 55.5° (for example, 54.5°); the 2θ angle corresponding to 110 crystal plane of artificial graphite is 76.5° to 78.5° (for example, 77.4°).

[0291] An exemplary preparation method of the electrode plate for testing the orientation index OI of the above-mentioned artificial graphite is as follows:

[0292] The artificial graphite of the present application, styrene-butadiene rubber (SBR) as a binder, sodium carboxymethyl cellulose (CMC-Na) as a thickener, and a conductive agent (Super P) are dispersed in deionized water in a mass ratio 96.2:1.8:1.2:0.8, and mixed uniformly to obtain a slurry; the slurry is applied evenly to a copper foil current collector in an areal density of 10 mg / cm2 to 11 mg / cm2 (for example, 10.7 mg / cm2), the dried electrode plate is cold pressed through a cold pressing to obtain a compacted density of 1.6 g / cm3 to 1.7 g / cm3 (for example, 1.65 g / cm3). The prepared electrode plate is placed in an X-ray diffractometer, and the peak area C004 of the 004 crystal plane diffraction peak of the artificial graphite in the electrode plate and the peak area C110 of the 110 crystal plane diffraction peak of the artificial graphite are obtained by X-ray diffraction analysis. The orientation index OI value is C004 / C110. Thickness and quality characterization of the amorphous carbon layer:

[0293] A transmission electron microscopy (TEM) analysis was performed on the carbon- based particles at multiple locations of the cross section of the negative electrode active material layer. Based on the obvious dividing line formed between the amorphous carbon layer and the carbon-based core indicated in the TEM photograph, the average value of the coating layer was statistically estimated as the thickness of the amorphous carbon layer in this application.

[0294] Analysis of the mass proportion of the amorphous carbon layer: Assuming that the carbon-based particles are spherical, based on the thickness of the amorphous carbon layer and the statistical data of the particle size of the carbon-based particles, the volume proportion of the amorphous carbon layer in the carbon-based particles can be estimated based on the volume of the carbon-based particles and the volume of the carbon-based core. Further, based on the average mass of a single carbon-based particle, the volume of the carbon-based core (which can be calculated or obtained based on statistics from TEM test photos) and the density of the carbon-based core, the mass proportion of the amorphous carbon layer in the carbon-based particles may be estimated.

[0295] According to the test results, in the secondary carbon particles coated with an amorphous carbon layer prepared in each embodiment, the thickness of the amorphous carbonlayer is controlled within the range of 200 nm to 500 nm, and the mass proportion of the amorphous carbon layer in the secondary carbon particles is controlled within the range of 1.3 % to 3.3 %. Particle size test:

[0296] Treatment of the sample to be tested: 1 to 2 drops of hand sanitizer (Blue Moon brand, containing surfactants such as sodium dodecyl sulfate) and then 20mL of deionized water were added to about 0.5 g of the sample particles. The sample was fully dispersed by ultrasonic treatment for 5 minutes with a ultrasonic power of 120W. The average particle size A of the artificial graphite can be measured by a laser particle size analyzer, for example, a Malvern Master Size 3000 laser particle size analyzer. Specifically, the volume average particle size Dv50 of the artificial graphite can be measured by a laser particle size analyzer; The dispersion medium used for the test can be water, such as deionized water. Laser particle size analysis can be carried out according to standard GB / T 19077.1-2016. Pouch cell testing method:

[0297] (1) Preparation of negative electrode slurry

[0298] The secondary negative electrode particles, the conductive agent (conductive carbon SP) were dry mixed in a stirring tank for 5 minutes, and then a dispersant (sodium carboxymethyl cellulose) was added and dry mixed for 20 minutes Then deionized water was added and stirred, keeping the solid content at about 60 wt.%, stirring for 120 minutes, and finally a binder (aqueous binder styrene-butadiene rubber latex) and deionized water were added, keeping the solid content at about 50 wt.%. The vacuum degree was kept ≤-0.05MPa, and the temperature of the entire processing and stirring process was kept at 5 °C to 50 °C. The negative electrode slurry was prepared.

[0299] Among them, the mass parts of graphitized particles, secondary negative electrode particles, conductive carbon SP, styrene-butadiene rubber emulsion, and sodium carboxymethyl cellulose are 84.6 parts, 9.4 parts, 2 parts, 2.5 parts, and 1.5 parts, respectively, that is, the mass ratio is 84.6:9.4:2:2.5:1.5. (2) Preparation of negative electrode sheet:

[0300] The negative electrode slurry prepared in step (1) is uniformly coated on both sides of a current collector copper foil. The negative electrode sheet is obtained after drying, cold pressing, trimming, cutting and stripping. (3) Preparation of positive electrode sheet:

[0301] The positive electrode active material Nickel-Manganese-Cobalt (NMC811), the conductive agents Multiwall Carbon nanotube and SP, and the binder polyvinylidene fluoridewere fully stirred and mixed in an N-methylpyrrolidone solvent system at a mass ratio of 97.4:0.7:0.5:1.4 to obtain a positive electrode slurry.

[0302] The positive electrode slurry was evenly coated on both sides of a current collector aluminum foil with a thickness of 13 μm, with a coating amount of about 20.13 mg / cm 2 on 5 one side. The positive electrode sheet was obtained after drying, cold pressing, trimming, cutting and striping. (4) Preparation of electrolyte:

[0303] In an argon atmosphere glove box (H2O content is less than 0.1 ppm, O2content is less than 0.1 ppm, where ppm means one part per million by volume), ethylene carbonate (EC) 0 and ethyl methyl carbonate (EMC) are mixed evenly in a volume ratio of 3:7, lithium salt LiPF6is added, and stirred evenly to prepare an electrolyte. The mass percentage concentration of lithium salt LiPF 6 in the electrolyte is 12.5%. (5) Isolation film:

[0304] A polyethylene (PE) porous polymer film is used as the isolation membrane. 5 (6) Preparation of lithium-ion batteries:

[0305] The negative electrode sheet (prepared in step (2)), the isolation film and the positive electrode sheet (prepared in step (3)) are stacked in order, with the isolation film placed between the positive and negative electrode sheets to play an isolating role, and then wound to obtain a bare cell, which is then inserted into a battery casing. After baking, liquid injection, 0 standing, packaging, formation, capacity division and other processes, a lithium-ion battery is prepared, which is a lithium-ion secondary battery. Example 3

[0306] The evolution of the physical and electrochemical properties of various samples were recorded after grinding and carbonization, and after grinding, carbonization, and 5 graphitization in Tables 3 and 4: Table 3: Summary of the physical characteristics after grinding and carbonization Measurement Units Coke w / o binder Pitch + binder Coke + binder Grinded Carbonized Grinded Carbonized Grinded CarbonizedTable 4: Summary of the physical characteristics after grinding, carbonization, and graphitization Measurement Units Coke w / o binder Pitch + binder Coke + binder True density g / cm32.26 2.21 2.24 Discharge capacity mAh / g 344 345 340n the art in light of the foregoing description without departing from the spirit or scope of the present disclosure and that when numerical lower limits and numerical upper limits are listed herein, ranges from any lower limit to any upper limit are contemplated.

[0308] 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 that 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 may 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.

[0309] 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.

[0310] 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. 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.

[0311] All numerical values within the detailed description herein are modified by “about” the indicated value, and take into account experimental error and variations that would be expected by a person having ordinary skill in the art.

[0312] One or more illustrative embodiments 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 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 time-consuming, such efforts would be, nevertheless, a routine undertaking for one of ordinary skill in the art and having benefit of this disclosure.

[0313] While compositions and methods are described herein in terms of “comprising” or “having” various components or steps, the compositions and methods can also “consist essentially of” or “consist of” the various components and steps.

[0314] 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

CLAIMS What is claimed is:

1. A method of fabricating a negative electrode comprising: grinding a petroleum precursor at a temperature below a softening point of the petroleum precursor to form at least precursor particles, wherein the petroleum precursor comprises a quinoline soluble to quinoline insoluble ratio above 0.10 (QS / QI > 0.10), a benzene soluble to benzene insoluble ratio above 0.25 (BS / BI > 0.25), and a ratio of hexane insoluble to benzene soluble of less than 3 (HI / BS<3.0); carbonizing the precursor particles by heating to a temperature from about 700 ^C to about 1800 ^C to form at least carbonized particles; and graphitizing by heating to a graphitization temperature of about 2000 ^C to about 4000 ^C to form at least graphitized particles.

2. The method of claim 1, further comprising stabilizing the precursor particles by heating to a stabilizing temperature from about 100 ^C to about 400 ^C.

3. The method of any one of the preceding claims, further comprising granulating the precursor particles by heating to a temperature from about 200 ^C to about 900 ^C and deagglomerating agglomerated particles after stabilizing the precursor particles, wherein granulating further comprises using at least one binder, wherein the at least one binder comprises a thermally and chemically untreated petroleum precursor.

4. The method of any one of the preceding claims, wherein granulating further comprises using at least one binder, wherein the at least one binder is selected from the group of binders consisting of asphalt, phenolic resin, furfural resin, epoxy resin, lignin, starch, and any combination thereof.

5. The method of any one of the preceding claims, wherein granulating further comprises using at least one binder comprising a graphitization catalyst.

6. The method of any one of the preceding claims, wherein a ramp rate for increasing a temperature of the precursor particles to the stabilizing temperature is from about 0.5 ^C per minute to about 10 ^C per minute.

7. The method of any one of the preceding claims, wherein a ramp rate for increasing a temperature of the precursor particles to the stabilizing temperature is from about 3 ^C per minute to about 10 ^C per minute in air.

8. The method of any one of the preceding claims, wherein the precursor particles after the grinding have a particle size of Dv50 ranging from about 1 micron to about 25 microns.

9. The method of any one of the preceding claims, wherein the petroleum precursor comprises a quinoline soluble to quinoline insoluble ratio above 0.40 (QS / QI > 0.40), a ratio of benzene soluble to benzene insoluble above 0.6 (BS / BI > 0.6), and a ratio of hexane insoluble to benzene soluble of less than 2 (HI / BS<2.0).

10. The method of any one of the preceding claims, wherein the precursor particles are held at the stabilizing temperature for a period of about 10 minutes to about 6 hours.

11. The method of any one of the preceding claims, wherein the carbonizing is performed in an environment comprising about 0.1 mol% oxygen and / or below at a temperature of 1200 ^C for 8 hours.

12. The method of any one of the preceding claims, wherein the graphitizing is performed in an environment comprising about 0.1 mol% oxygen and / or below at a temperature of 3000 ^C for 2 hours.

13. The method of any one of the preceding claims, wherein grinding the precursor particles is performed after the carbonizing the precursor particles.

14. The method of any one of the precedent claims, further comprising de-agglomerating the carbonized precursor particles.

15. The method of any one of the preceding claims, wherein the graphitized particles have a degree of graphitization of about 90% or more.

16. The method of any one of the preceding claims, wherein the graphitized particles comprise primary negative electrode particles.

17. The method of any one of the preceding claims, wherein the graphitized particles comprise secondary negative electrode particles.

18. A composition for negative electrodes comprising: secondary negative electrode particles in an amount from about 2 % to about 100%; wherein the secondary negative electrode particles have a degree of graphitization of about 80% or more and a specific surface area of about 0.1 m2 / g to about 6 m2 / g; wherein the secondary negative electrode particles comprise microparticle active material produced from at least one carbon source selected from the group consisting of mesophase pitch, needle coke, petroleum coke, and any combination thereof, wherein the at least one carbon source comprises a quinoline soluble to quinoline insoluble ratio above 0.10 (QS / QI > 0.10), a ratio of benzene soluble to benzene insoluble above 0.25 (BS / BI > 0.25), and a ratio of hexane insoluble to benzene soluble of less than 3 (HI / BS<3.0); and wherein the secondary negative electrode particles are granulated using at least one binder, wherein the at least one binder is selected from the group of binders consisting of pitch, asphalt, phenolic resin, furfural resin, epoxy resin, lignin, starch, and any combination thereof.

19. The composition of claim 18, wherein the at least one binder comprises a graphitization catalyst.

20. The composition of claim 18, wherein the composition comprises primary negative electrode particles, wherein the primary negative electrode particles comprise mesophase pitch based graphite, needle coke-based graphite, petroleum coke-based graphite, graphitization catalyst, or any combination thereof.

21. The composition of claim 20, wherein only one of the secondary negative electrode particles, the primary negative electrode particles, and the binder comprises the graphitization catalyst.

22. The composition of claim 18, wherein the at least one binder is petroleum pitch, mesophase pitch, isotropic pitch, or any combination thereof.

23. The composition of claim 18, wherein the secondary negative electrode particles and the binder comprise a graphitization catalyst.

24. An electrode produced from the composition of any one of claims 18 to 23.

25. A battery comprising the electrode of claim 24.

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