Carbon particles and method for producing the same

Abstract

The present invention relates to carbon particles comprising at least 97 wt.% carbon, based on the total weight of the carbon particles, at most 0.2 wt.% impurities, based on the total weight of the carbon particles, at least 0.08 wt.% boron, based on the total weight of the carbon particles, and at most 0.05 wt.% boron carbide, based on the total weight of the carbon particles. The present invention also relates to a method for producing the carbon particles, comprising a graphitization step in an electric field. The present invention also relates to the use of the carbon particles as an active material in a negative electrode of a battery.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Provisional Application No. 63 / 406,932, filed September 15, 2022, the disclosure of which is incorporated herein by reference in its entirety.

[0002] The present invention relates to carbon particles, their method of manufacture, and their use as the active material in the negative electrode of a battery. [Background technology]

[0003] Because carbonaceous materials can electrochemically store and generate lithium ions, they have been investigated as active materials for the negative electrodes of lithium-ion batteries; these electrodes are often called anodes, depending on their role during battery discharge.

[0004] In particular, graphite, a crystalline layered allotrope of carbon, has been shown to possess both a high specific capacity and a low discharge potential close to that of lithium metal, enabling the realization of high-energy density batteries. Furthermore, these graphite anode materials have been developed in a variety of forms that make lithium-ion batteries commercially viable in terms of safety, shelf life, and charge-discharge cycle life. Therefore, graphite is currently the most promising active material for lithium-ion secondary batteries.

[0005] The distance between two adjacent layers of graphite is d, obtained from powder X-ray diffraction measurements. 002 It is expressed as the value of d 002 The value is often called the layer distance. 002 The lower the value, the higher the specific capacity.

[0006] Using Bragg's law, which is: 2 * d hkl * sin(Theta n )=n * lambda where: ·dhkl = face-to-face distance ·lambda=X-ray wavelength n = reflection order Theta n = Bragg angle of nth reflection In the case of graphite, the predominant stacking structure is hexagonal, and is represented by the formula: 1 / d hkl 2 =(4 / 3 * (h 2 +k 2 +h * k)+l 2* (a / c) 2 ) * 1 / a 2 where c=2 * d 002 where a is the length of the diagonal of the hexagon constituting the graphene layer, and a=2 * d 110 is.

[0007] Impurities, particularly sulfur and oxygen, present in graphite and the respective precursor materials often have a detrimental effect on the specific capacity obtainable from a particular graphite sample. Also, particle size and particle shape can affect the specific capacity obtainable from a particular graphite sample, with the main aspect affected by typical particle size being the rate capability of the anode.

[0008] To meet the high specific capacity requirements for battery applications, natural graphite must be shaped, sized, and purified. Synthetic graphite, typically produced from coke in a process called graphitization, has also been used as an active material in anodes. Graphitization, which at least partially crystallizes previously amorphous carbon and removes some impurities, is typically carried out in the absence of an oxidizing atmosphere at high temperatures above 1700°C, preferably above 2500°C, typically achieved by resistive heating by passing a large current through the carbonaceous material. Graphitization is believed to be affected by temperature exposure over time, but at low temperatures, the time required to achieve a sufficient degree of graphitization is prohibitive for a commercially viable process.

[0009] Historically, the so-called Acheson process has been applied, which requires batch processing and large amounts of energy. The drawbacks of the Acheson process are: long cooling times, non-uniform product properties, limited atmosphere control, limited purification efficiency, and large amounts of by-products. These drawbacks require very high processing temperatures for long periods of time.

[0010] The initial charging of a lithium-ion secondary battery is commonly referred to as "formation." During the formation of a lithium-ion secondary battery containing an anode with graphite as the active material, non-aqueous solvents or additives in the electrolyte are reduced and decomposed on the surface of the graphite, forming a solid electrolyte interface, or so-called SEI (solid electrolyte interface) layer. In this process, not only organic molecules but also lithium ions are consumed and irreversibly lost, forming various lithium salts in the SEI layer.

[0011] The stability of the SEI layer itself and the surface (and consequently the bulk) of the graphite particles themselves during many charge-discharge cycles and storage is one of the properties that is crucial to the commercial viability of a battery system.

[0012] To reduce the degree of lithium loss on the first cycle and stabilize the SEI layer over many cycles, the graphite particles that make up the anode can be modified, such as by controlling their chemical surface activity. Coating the particles with a more inert layer before exposure to the electrolyte has proven beneficial, and the application, post-processing, and finishing of this coating (often by a secondary heat treatment at low temperature or an additional secondary coating by CVD or other techniques) must be carefully performed to successfully integrate the particles into the overall battery system.

[0013] Various approaches have been taken in the search for materials that integrate solutions to the many demands of lithium-ion batteries in a reliable, simple, and cost-effective manner. One very interesting concept is doping carbon with its natural alloying partners, boron and nitrogen. However, the solutions presented in the literature so far have met with limited success.

[0014] Challenges with this approach include the distribution of alloying element sources often contained in coke precursors, such as sulfur, which can affect graphitization performance as impurities or can negatively affect the integrity of the graphite particles through other powders. Slow heating and cooling rates can lead to the formation of undesirable structures, as outlined below.

[0015] An example of a coated carbon particle is described in U.S. Pat. No. 6,869,546, which describes a carbon material comprising a first carbon material serving as an inner core particle having an outer surface, and a coating of a second carbon material on the outer surface of the first carbon material, the second carbon material comprising at least 1% and up to 15% by weight of boron.

[0016] Boron and nitrogen can partially substitute for carbon within the graphite structure. Boron and nitrogen are present in natural graphite (although not necessarily in substitutional positions within the graphite layers), and are sometimes intentionally added during the production of synthetic graphite, as boron is said to promote the crystallization of carbon to graphite during high-temperature processing, allowing for lower processing temperatures.

[0017] Synthetic graphitic carbon materials containing boron and / or nitrogen have been reported.

[0018] For example, U.S. Pat. No. 5,358,805 describes a secondary battery including a positive electrode, an electrolyte, and a negative electrode capable of reversibly intercalating lithium; the negative electrode includes a carbon compound having a graphite crystal structure in which carbon (C) is partially substituted with both boron (B) and nitrogen (N), and the carbon compound has the formula BC3N.

[0019] In particular, it has been hypothesized that placing boron and / or nitrogen on the surface of carbon particles improves the surface chemistry of said particles. Adding boron and nitrogen during graphitization can improve the formation and stabilization of the SEI layer, aiming to integrate the specified elements onto the carbon surface. However, this can result in the formation of a boron nitride surface coating in addition to the boron and nitrogen doping. While the boron nitride coating may enhance the chemical stability of graphite, its insulating properties adversely affect the diffusion of lithium ions and the interaction between the SEI layer, the electrolyte, and the surface of the anode particles. Therefore, controlling and adjusting the amount of boron nitride is of great interest. In this regard, U.S. Patent Application Publication No. 2018 / 0337423 describes anode active materials containing graphite containing boron and nitrogen, and notes that X-ray photoelectron spectroscopy (XPS) can be used to observe the ratio of the peak area of ​​boron bound to nitrogen to the total boron peak area, taking into account the boron 1s spectrum, respectively.

[0020] Furthermore, Japanese Patent Application Laid-Open No. 2000-012020 discloses a graphitized carbon powder containing boron and nitrogen, and the 10% cumulative diameter [d 10 The negative electrode material for a lithium secondary battery is described, in which the particle size is 5 to 25 μm.

[0021] JP 2000-012021 A discloses a graphitized carbon powder containing boron and nitrogen, and the specific surface area calculated by desorption of nitrogen into the carbon powder is 10 m 2 / g or less.

[0022] A post-graphitization surface treatment is described in U.S. Patent Application Publication No. 2001 / 0051300, which results in a graphite powder containing 0.01 to 5.0 wt. % boron, with loop-shaped closed structures at the ends of the graphite c-plane layers on the powder surface, and with a density of the gap plane sections between adjacent closed structures of 100 / μm or more and 1500 / μm or less.

[0023] Similar to boron nitride, boron carbide may be formed during the graphitization process, but not exclusively on the surface of the particle. Boron carbide has the disadvantage that it may act as an abrasive when particles containing boron carbide are coated onto other surfaces, such as metal foil. Furthermore, boron carbide is substantially non-reactive, thereby reducing the gravimetric and volumetric capacity of the particles.

[0024] In view of the prior art, it is an object of the present invention to provide carbon particles that can be used in anodes of lithium-ion batteries, which should result in anodes and / or batteries with, inter alia, long shelf life and / or high specific capacity and / or high cycle life.

[0025] It is a further object of the present invention to provide a method for producing such carbon particles, which should in particular allow for the preparation of particles with tailored properties, preferably while eliminating or at least limiting the boron and nitrogen doping trade-off known from other approaches. Other objects, features and advantages of the present invention will become more fully apparent from the following description. [Prior art documents] [Patent documents]

[0026] [Patent Document 1] U.S. Patent No. 6,869,546 [Patent Document 2] U.S. Patent No. 5,358,805 [Patent Document 3] US Patent Application Publication No. 2018 / 0337423 [Patent Document 4] Japanese Patent Application Laid-Open No. 2000-012020 [Patent Document 5] Japanese Patent Application Laid-Open No. 2000-012021 [Patent Document 6] US Patent Application Publication No. 2001 / 0051300 Summary of the Invention

[0027] Some or all of the above objects are solved by the carbon particles according to claim 1, the method according to claim 12, the use according to claim 19, and the battery according to claim 20.

[0028] Without intending to be bound by scientific theory, it is believed that impurities within the carbon particles can affect the electrochemical properties and the crystallinity of the graphite, and therefore it may be advantageous to remove them during the graphitization process. Furthermore, impurities, especially metallic ones, carry the risk of promoting side reactions in the chemical battery system, posing a risk to the battery's operation, its storage and cycle life.

[0029] While boron can be beneficial with respect to these properties, the formation of boron carbide clusters is thought to render boron inactive, and macrocrystals are known to be abrasive, so boron carbide formation should be suppressed. Surprisingly, we found that granulation of carbonaceous particles with an organic binder, followed by carbonization and finally graphitization in an electric field, particularly an electrothermal fluidized bed, followed by deagglomeration of the granules, particularly by gentle mechanical disintegration to regenerate the particles, allows the use of a wide range of precursor particle sizes and yields particles with a graphitized core and an unstructured carbon shell. In this way, we can combine the many benefits of boron and nitrogen doping while avoiding or at least limiting the potential tradeoffs known from other approaches.

[0030] This process is believed to allow controlled introduction of boron and nitrogen as dopants into the bulk and surface of the particles, limiting the formation of boron carbide and boron nitride. The carbon particles of the present invention can be used in lithium-ion secondary batteries, specifically anodes as negative electrode active materials. The resulting batteries may exhibit, among other things, a long shelf life and / or a high specific capacity and / or a long cycle life. Without wishing to be bound by scientific theory, it is believed that the carbon particles contain boron only in very small amounts as clusters, which is helpful in achieving anodes and / or batteries with desirable properties. [Brief explanation of the drawings]

[0031] [Figure 1] 1 is a graph showing the relationship between boron substitution and degree of graphitization. [Figure 2] A portion of the XPS spectrum of natural flake graphite purified and boronized in an electrically heated fluidized bed reactor in a nitrogen atmosphere in the presence of a boron source at a blackbody radiation temperature of approximately 2300°C and a residence time similar to those in Examples 1-6 below. The boron nitride was mechanically removed from the surface using tape. [Figure 3] The size distribution of some particles is shown. DETAILED DESCRIPTION OF THE INVENTION

[0032] Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to these embodiments.

[0033] According to one embodiment, the carbon particles have a diameter of 0.5 to 50 m. 2 / g, preferably 0.5 to 10m 2 / g, more preferably 1 to 3 m 2 / g, more preferably 1 to 2 m 2 / g. The BET surface area is preferably measured by nitrogen adsorption / desorption. Optimizing the specific surface area is important for graphite as an active material in lithium-ion battery anodes, because a high specific surface area can increase irreversible lithium loss during SEI formation, while a low specific surface area can decrease the conductivity and rate capability of the anode. Carbon particles with the BET surface area described herein can have a particularly good balance between lithium loss and conductivity.

[0034] According to another embodiment, the carbon particles have a d of 0.3363 nm to 0.3355 nm, preferably 0.3359 nm to 0.3355 nm. 002 spacing, and / or d of 0.120 nm to 0.126 nm, preferably 0.1229 nm to 0.1236 nm, more preferably 0.123027 nm to 0.123244 nm 110 With interval d 002 The lower the d, the higher the specific capacity, which can be a measure of the degree of graphitization and crystallinity of the carbon. 110 The spacing is affected by boron doping, and the d 110 The spacing may indicate a uniform distribution of boron atoms in the graphite structure, as opposed to the formation of clusters at higher boron contents.

[0035] According to one embodiment, the XPS spectrum of the carbon particles has a first peak between 184.0 eV and 188.0 eV, preferably between 185.0 eV and 187.5 eV, more preferably between 185.5 eV and 187.0 eV, and most preferably at about 186.5 eV, and / or a second peak between 188.5 eV and 192.0 eV, preferably between 189.0 eV and 191.5 eV, more preferably between 189.5 eV and 191.0 eV, and most preferably at about 190.3 eV, and / or is substantially absent at about 187.7 eV. Preferably, the intensity ratio between the first peak and the second peak in the XPS spectrum is between 0.25 and 6.0, preferably between 0.5 and 2, and more preferably between 0.8 and 1.25. A high intensity ratio between the first peak and the second peak indicates the strong presence of BN bonds, which is usually associated with the presence of boron nitride. The first peak and / or the second peak are preferably prominent in the XPS spectrum. The first peak in the XPS spectrum is preferably a B1s peak indicating the presence of boron-carbon bonds on the surface of the carbon particles. The first peak in the XPS spectrum is also referred to as a B1s(BC) peak. The second peak in the XPS spectrum is preferably a B1s peak indicating boron-nitrogen bonds on the surface of the carbon particles. The second peak in the XPS spectrum is also referred to as a B1s(BN) peak. The peak at 187.7 eV is preferably a B1s peak indicating boron-boron bonds and / or boron-boron clusters. The peak at 187.7 eV is preferably below the detection limit.

[0036] In the XPS spectra, the boron nitride is removed by mild treatment with aqueous caustic NaOH (10% NaOH in an Anton Parr Multiwave 7000 microwave digester using a PTFE sample container for 20 minutes at 250°C, followed by neutralization with nitric acid) to allow nitrogen to be present in the hard carbon shell itself. The remaining BN peak near 190.3 eV indicates nitrogen doped into the shell of the carbon particles, improving their surface properties.

[0037] According to yet another embodiment, the carbon particles comprise at least 97.5 wt. %, preferably at least 98 wt. %, and more preferably at least 98.5 wt. % carbon, based on the total weight of the particles. A higher carbon content can increase the proportion of active material capable of intercalating lithium in anodes fabricated therefrom, potentially resulting in higher specific capacity. A higher carbon content can also decrease the content of various potentially adverse impurities.

[0038] According to a preferred embodiment, at least 85% by weight of the carbon contained in said carbon particles is graphitic carbon, more preferably at least 90% by weight, and most preferably at least 95% by weight.

[0039] The term "impurities" here preferably refers to particle constituent elements other than carbon, boron, and nitrogen. Impurities can affect the properties of graphite, particularly with regard to graphite crystallinity and layering. Furthermore, metallic impurities, in particular, carry the risk of promoting side reactions in the chemical battery system, thus posing a risk to the battery's control, its storage, and cycle life. The initial impurities may depend on the source and previous processing of the carbonaceous material precursor. Preferably, the carbon particles disclosed herein contain small amounts of impurities. According to one embodiment, the carbon particles contain at most 0.1 wt. %, preferably at most 0.05 wt. %, more preferably at most 0.04 wt. %, even more preferably at most 0.03 wt. %, and most preferably at most 0.025 wt. % of impurities, based on the total weight of the carbon particles.

[0040] According to yet another embodiment, the impurities are metallic impurities, such as at least one of transition metals, particularly vanadium and / or iron, oxygen, and sulfur, preferably at least one of transition metals, particularly vanadium and / or iron, oxygen, and sulfur. Preferably, the carbon particles contain at most 100 ppm oxygen and 100 ppm sulfur. Oxygen levels and total nitrogen content were measured using a Leco ONH836 gas analyzer, sulfur levels were measured using a LECO SC-432 sulfur measurement unit, and vanadium, iron, and other elements, particularly metals, were measured using a Jobin Yvon Horiba Ultima 2 ICP-OES after nitric acid-sulfuric acid digestion (for vanadium and other metals) and hydrochloric acid digestion (for iron), respectively.

[0041] According to yet another embodiment, the carbon particles contain at most 0.03 wt. %, preferably at most 0.02 wt. %, more preferably at most 0.01 wt. %, and most preferably at most 0.005 wt. % boron carbide, based on the total weight of the carbon particles; and / or the carbon particles contain at most 0.5 wt. % boron nitride, preferably at most 0.3 wt. % boron nitride, more preferably at most 0.1 wt. % boron nitride, based on the total weight of the carbon particles. The carbon particles may contain boron nitride in an amount of 0.05 wt. % to 1 wt. %, preferably 0.1 wt. % to 0.8 wt. %, based on the total weight of the carbon particles. If boron nitride is present, it is preferably located on the surface of the carbon particles. It has been found that when the carbon particles contain boron and / or nitrogen in amounts within the above ranges, the formation of dopant-rich clusters and / or phases and / or particles and / or surfaces is reduced. Dopant-rich clusters, phases, particles, and / or surfaces may reduce the lithium intercalation and deintercalation capabilities of the carbon particles or may even contribute to irreversible lithium loss through side reactions. Furthermore, boron carbide may act as an abrasive when a slurry containing the carbon particles is applied to a copper foil to make a battery negative electrode. Furthermore, boron carbide is essentially non-reactive, thereby reducing the gravimetric and volumetric capacity of the negative electrode.

[0042] Boron can be present in the carbon particles in various forms. For example, boron can be present in the form of boron nitride. The boron nitride is preferably located on the surface of the carbon particles. Boron can be present in the form of boron carbide.

[0043] Boron nitride was prepared by microwave digestion in an Anton Paar Multiwave 7000 microwave digester using caustic (NaOH) at temperatures up to 250 °C. aq The residue from the caustic treatment can be used as a method to quantify boron nitride using ICP-OES of boron.

[0044] The upper limit of the amount of boron carbide can be determined as follows. During XRD measurement of the degree of graphitization, boron carbide reflections can be identified in the diffractogram. The ash of a sample of the carbon particles (3 g sample, 780-800 °C in a muffle furnace for 8 hours, air) can then be visually inspected for boron carbide particles. The ash is white, with boron nitride visible as white particles and boron carbide visible as gray to black specks in the ash. The upper limit of boron carbide in the carbon particles can then be determined by comparing the amount of gray to black boron carbide specks in the ash with the amount of white boron nitride particles, which can be determined using ICP-OES as described herein. XRD analysis can also be performed on the ash as an additional control.

[0045] Furthermore, boron may be present in place of carbon atoms. For example, if the carbon particles include graphene sheets or graphite crystallites, or an amorphous carbon structure, boron atoms may be located at lattice sites of the graphene sheets or graphite crystallites, replacing carbon atoms at these lattice sites, or boron atoms may replace carbon atoms in the amorphous carbon structure. In this case, the boron may be said to be in substitutional positions. The amount of boron at substitutional positions in the carbon particles can be determined, inter alia, by the following procedure:

[0046] First, 3 g of sample was ashed in a muffle furnace at 780-800°C in air for 8 hours. Second, leaching boron oxide from the ash with 2% hot nitric acid, followed by filtering the boron nitride from the ash to obtain a nitric acid filtrate; Third, ICP-OES is used to determine the boron content in the nitric acid filtrate.

[0047] The carbon particles comprise at least 0.08 wt.% boron based on the total weight of the carbon particles. According to an embodiment, the carbon particles comprise at least 0.1 wt.%, preferably at least 0.15 wt.%, more preferably at least 0.2 wt.%, even more preferably at least 0.3 wt.% boron based on the total weight of the carbon particles, and / or at most 2.3 wt.%, preferably at most 2 wt.%, more preferably at most 1.5 wt.%, most preferably at most 1.3 wt.% boron based on the total weight of the carbon particles.

[0048] According to a preferred embodiment, the carbon particles contain 0.1 wt % to 2 wt %, more preferably 0.3 wt % to 1.5 wt %, of boron. The boron content in the carbon particles preferably relates to boron at substitution sites in the carbon particles. Carbon particles having a boron content within the range described herein, particularly carbon particles having a boron content at substitution sites, can suppress the formation of by-products not involved in the insertion or deinsertion of lithium ions, and can maintain a high specific discharge capacity.

[0049] According to one embodiment, the carbon particles comprise both boron nitride and boron, preferably in a weight ratio of at least 0.0005 weight percentage points of boron nitride per weight percentage point of boron to a maximum of 2.5 weight percentage points of boron nitride per weight percentage point of boron, more preferably at least 0.001 weight percentage points of boron nitride per weight percentage point of boron to a maximum of 1 weight percentage point of boron per weight percentage point of boron, and even more preferably at least 0.002 weight percentage points of boron nitride per weight percentage point of boron to a maximum of 0.1 weight percentage point of boron nitride per weight percentage point of boron.

[0050] According to one embodiment, the carbon particles comprise both boron nitride and boron, preferably in a weight ratio of at least 0.02 (wt% boron nitride / wt% boron) to a maximum of 12.5 (wt% boron nitride / wt% boron), more preferably at least 0.05 (wt% boron nitride / wt% boron) to a maximum of 1 (wt% boron nitride / wt% boron), and even more preferably at least 0.07 (wt% boron nitride / wt% boron) to a maximum of 0.3 (wt% boron nitride / wt% boron).

[0051] According to yet another embodiment, the carbon particles contain nitrogen.

[0052] Advantageously, the carbon particles contain nitrogen in an amount of at least 0.005 wt %, preferably 0.01-0.05 wt %, more preferably 0.015-0.04 wt %, and most preferably 0.02-0.03 wt %, based on the total weight of the carbon particles. The nitrogen content in the carbon particles is preferably measured after removing boron nitride from the surface of the carbon particles. Nitrogen doping in the range described herein may reduce the formation of by-products not involved in lithium ion insertion or deinsertion and help maintain a high specific discharge capacity. The nitrogen content in the carbon particles after removing boron nitride can be measured by XPS after removing boron nitride.

[0053] According to a preferred embodiment, the carbon particles contain boron and nitrogen.

[0054] Advantageously, the carbon particles are at least 97 wt. % carbon, based on the total weight of the carbon particles; impurities up to 0.2% by weight based on the total weight of the carbon particles; at least 0.08 wt. % boron based on the total weight of the carbon particles; up to 0.05% by weight of boron carbide based on the total weight of the carbon particles; and Contains nitrogen.

[0055] The boron is preferably in substitutional positions within the carbon particles.

[0056] According to another preferred embodiment, the carbon particles are at least 97 wt. % carbon, based on the total weight of the carbon particles; impurities up to 0.2% by weight based on the total weight of the carbon particles; at least 0.15 wt. % boron based on the total weight of the carbon particles; A maximum of 0.05% by weight of boron carbide based on the total weight of the carbon particles Includes.

[0057] The boron is preferably in substitutional positions within the carbon particles.

[0058] According to another preferred embodiment, the carbon particles are at least 97 wt. % carbon, based on the total weight of the carbon particles; impurities up to 0.2% by weight based on the total weight of the carbon particles; at least 0.15 wt. % boron based on the total weight of the carbon particles; up to 0.05% by weight of boron carbide based on the total weight of the carbon particles; and Contains nitrogen.

[0059] According to another preferred embodiment, the carbon particles are at least 97 wt. % carbon, based on the total weight of the carbon particles; impurities up to 0.2% by weight based on the total weight of the carbon particles; at least 0.15 wt. % boron based on the total weight of the carbon particles; up to 0.05% by weight of boron carbide based on the total weight of the carbon particles; and Contains at least 0.0003% nitrogen and a maximum of 1% nitrogen.

[0060] According to another preferred embodiment, the carbon particles are at least 97 wt. % carbon, based on the total weight of the carbon particles; impurities up to 0.2% by weight based on the total weight of the carbon particles; at least 0.15 wt. % boron based on the total weight of the carbon particles; at least 0.0001% and at most 0.05% by weight of boron carbide, based on the total weight of the carbon particles; and Contains nitrogen, The carbon particles are preferably core-shell particles, in particular having a hard carbon shell.

[0061] According to another preferred embodiment, the carbon particles are at least 97 wt. % carbon, based on the total weight of the carbon particles; impurities up to 0.2% by weight based on the total weight of the carbon particles; at least 0.08 wt. % boron based on the total weight of the carbon particles; up to 0.05% by weight of boron carbide based on the total weight of the carbon particles; Nitrogen, and containing boron nitride, wherein the boron nitride and boron are present in a weight ratio of at least 0.0005 weight percentage points of boron nitride per 1 weight percentage point of boron to 2.5 weight percentage points of boron nitride per 1 weight percentage point of boron.

[0062] According to another preferred embodiment, the carbon particles are at least 97 wt. % carbon, based on the total weight of the carbon particles; impurities up to 0.2% by weight based on the total weight of the carbon particles; at least 0.08 wt. % boron based on the total weight of the carbon particles; up to 0.05% by weight of boron carbide based on the total weight of the carbon particles; Nitrogen, and containing boron nitride, The boron nitride / boron weight ratio is at least 0.02 (wt % boron nitride / wt % boron) and up to 12.5 (wt % boron nitride / wt % boron).

[0063] According to yet another embodiment, the carbon particles have a particle size distribution d between 3 and 30 μm, preferably between 4 and 25 μm, more preferably between 5 and 20 μm. 50 Advantageously, the carbon particles have a particle size distribution d between 1 and 25 μm, preferably between 1.5 and 20 μm, more preferably between 2 and 15 μm. 10 It has.

[0064] Advantageously, the carbon particles have a particle size distribution d between 6 and 50 μm, preferably between 8 and 45 μm, more preferably between 10 and 35 μm. 90 Particles smaller than those specified above may irreversibly consume excess lithium through SEI formation, resulting in a reduced specific capacity, while particles larger than those specified above may slow lithium intercalation and deintercalation, resulting in a reduced anode rate capability. Particles outside the specified size distribution may adversely affect the anode manufacturing process, resulting in a poorly manufactured anode.

[0065] All particle size distributions reported herein are preferably by volume as determined by wet dispersion laser diffraction using a Microtrac S3500 after dispersion under sonication in a Branson 3510 ultrasonic bath using a Branson Ultrasonicator 250-ultrasonic probe with surfactant "Triton X100".

[0066] According to yet another embodiment, the carbon particles are core-shell particles comprising a shell of substantially non-graphitizable, particularly hard, carbon and a carbon core that is at least partially graphitizable and may still contain portions of graphitizable, particularly soft, carbon. Without wishing to be bound by scientific theory, it is believed that the hard carbon shell can reduce irreversible lithium loss due to SEI formation and / or side reactions and / or protect the inner surface of the particle core from similar side reactions, particularly electrolyte co-intercalation, which would lead to particle degradation. At the same time, the shell is conductive to lithium ions and therefore is believed not to affect the lithium storage properties of the core.

[0067] In the case of core-shell particles, the core advantageously accounts for 91% to 99% by weight, preferably 92% to 99% by weight, more preferably 94% to 98.5% by weight of the total weight of the carbon particle, and the shell accounts for 1% to 9% by weight, preferably 1% to 8% by weight, more preferably 1.5% to 6% by weight of the total weight of the carbon particle.

[0068] The shell is preferably formed from a carbonized binder.

[0069] Another aspect of the present disclosure relates to a method for producing the carbon particles disclosed herein, comprising: In the granulation step, the carbonaceous particles are granulated using a binder to obtain carbonaceous granules; In the carbonization step, the carbonaceous granules are heated to a temperature of at least 1000°C to obtain carbonized granules; In the graphitization step, the carbonized granules are introduced into an electric field to graphitize the carbonized granules, thereby producing graphitized granules; and In the deagglomeration step, the graphitized granules are deagglomerated, thereby obtaining the carbon particles; Here, at least one of the granulation step, the carbonization step, and the graphitization step is carried out in the presence of a boron source.

[0070] After the graphitization step, the graphitized granules preferably contain the carbon particles adhered to one another. In the deagglomeration step, the inter-particle contacts of the carbon particles in the graphitized granules are preferably broken down to deagglomerate the graphitized granules. Advantageously, the carbon particles themselves are not substantially broken down into smaller carbon particles. The deagglomeration of the graphitized granules is preferably achieved substantially by shear forces. The deagglomeration step is sometimes referred to as a mechanical disintegration step.

[0071] In one embodiment, the particle size distribution d 50 The particle size is 3 to 30 μm, preferably 4 to 25 μm, and more preferably 5 to 20 μm.

[0072] The carbonaceous particles have a particle size distribution d of 1 to 25 μm, preferably 1.5 to 20 μm, more preferably 2 to 15 μm. 10 It is advantageous to have

[0073] The carbonaceous particles have a particle size distribution d of 6 to 50 μm, preferably 8 to 45 μm, more preferably 10 to 35 μm. 90 It is advantageous to have

[0074] Preferably, the carbonaceous particles are selected from green petcoke particles, calcined petcoke particles, spherical flake graphite particles, spherical natural graphite particles, recycled anode powder particles, petroleum coke, pitch coke, carbonized wood, needle coke, sponge coke, shot coke, metallurgical coke, coal tar-based carbon, mesocarbon, anthracite, synthetic graphite, natural graphite, expanded graphite, carbonized polymers, carbon black, and mixtures thereof, and are preferably selected from green petcoke particles, calcined petcoke particles, spherical flake graphite particles, spherical natural graphite particles, recycled anode powder particles, and mixtures thereof. This method allows for a wide range of precursor particle sizes due to the formation of particle and binder granules in the granulation step, which may result in particles with the correct size distribution for subsequent processing and subsequent applications, particularly use as an active material in lithium-ion battery anodes. Similarly, this method allows for the use of a wide range of precursor materials due to the ability to remove impurities during the process.

[0075] According to yet another embodiment, the binder comprises at least one of starch, modified starch, phenolic resin, modified kraft lignin, styrene butadiene rubber (SBR), and latex. Preferably, the binder comprises or consists of starch and / or modified starch. These materials are widely available and inexpensive, and their composition allows them to be carbonized in the carbonization process described above. At the same time, the granulation process can be carried out using these binders under suitable conditions, preferably using water as a solvent. However, the present invention does not depend on the specific selection of such binders. The binder preferably promotes the agglomeration of the fine carbonaceous powder, particularly into carbonaceous granules. Advantageously, each carbonaceous particle is coated with a binder. Preferably, the particles are bound to the granules via the binder. In this way, the carbonaceous granules can produce carbonized granules after the carbonization process that are strong enough to pass through an electrically heated fluidized bed reactor with little mechanical disintegration, yet still allow for deagglomeration by mild mechanical treatment. Furthermore, in this manner, the individual carbon particles preferably retain an intact carbonized coating, particularly a hard carbon shell. Suitable binders for this purpose include, but are not limited to, binders comprising starch, modified starch, phenolic resin, modified kraft lignin, styrene butadiene rubber (SBR), or latex.

[0076] Preferably, the binder is used in an amount of 3 to 25% by weight, more preferably 5 to 20% by weight, based on the total weight of the carbonaceous particles and the binder.

[0077] When a solvent, such as water, is used, the solvent is used in an amount of 10 to 30% by weight, more preferably 15 to 25% by weight, based on the total weight of the binder and the carbonaceous particles.

[0078] According to yet another embodiment, in the carbonization step, the carbonaceous granules are heated in a first heating step to a first temperature of 30°C to 700°C, preferably 30°C to 300°C, and then in a second heating step to a second temperature of 300°C to 1400°C, preferably 300°C to 1300°C, more preferably 300°C to 1100°C. This step may require careful calcination, in line with prior art procedures for the production of graphitizable carbon, for optimal yield and process characteristics. Both heating steps can be carried out in the same furnace or in separate furnaces, in batch or continuous mode, with or without pretreatment of the granules.

[0079] According to yet another embodiment, the carbonaceous granules are heated to a first temperature for 0.1 to 20 hours, preferably 0.25 to 12 hours, and / or to a second temperature for 0.1 to 20 hours, preferably 0.25 to 12 hours. The carbonization time may depend on the oven used. When a rotary kiln is used, the carbonaceous granules are advantageously heated to the first and / or second temperature for 0.1 to 2 hours, preferably 0.5 to 1.5 hours. When an oven such as a debindering or sintering furnace is used, the carbonaceous granules are advantageously heated to the first and / or second temperature for 5 to 20 hours, preferably 10 to 15 hours, more preferably 10 to 12 hours. Under these carbonization conditions, the resulting carbonized granules may exhibit advantageous properties, particularly with regard to the possibility of graphitization in a subsequent process. The carbonization step can be carried out in a rotary kiln heated directly or indirectly under a reducing atmosphere containing less than 2% vol oxygen, or in an oven chamber heated directly or indirectly under a reducing atmosphere containing less than 2% vol oxygen, or in other suitable equipment.

[0080] The graphitization step can be carried out in a batch or continuous manner, and is preferably carried out in a continuous manner.

[0081] According to yet another embodiment, the carbonized granules are introduced into an electrically heated fluidized bed reactor during the graphitization step. Suitable electrically heated fluidized bed reactors are described, for example, in U.S. Pat. No. 3,684,446 or U.S. Pat. No. 3,807,961. In such reactors, the particles can be rapidly and directly heated under local plasma conditions. Compared to other reactor types, particularly the Acheson process, electrically heated fluidized bed reactors can offer advantages in one or more of the following: energy consumption per unit of product; product homogeneity due to mixing during fluidization; continuous operation versus batch operation, and the possibility of controlling throughput and / or residence time, taking into account boron content.

[0082] According to another embodiment, the graphitization step is carried out at a temperature of at least 2000°C, preferably at least 2300°C, more preferably at least 2400°C, and most preferably at least 2550°C. The aforementioned temperatures are in particular blackbody radiation temperatures. The graphitization step is preferably carried out at a temperature of at most 3500°C, more preferably at most 3200°C, and most preferably at most 3000°C. When the graphitization step is carried out in the aforementioned temperature range, the formation of boron nitride may be reduced.

[0083] According to yet another embodiment, the carbonized granules have an average residence time in the electric field during graphitization of 5 to 120 minutes, preferably 10 to 90 minutes, more preferably 15 to 60 minutes, and most preferably 20 to 45 minutes. These specific average residence times ensure high graphitization and refinement, boron diffusion, and uniform particle properties, while also allowing high throughput through the reactor.

[0084] According to yet another embodiment, the graphitized granules are cooled after the graphitization step to a temperature of 500°C or less over a period of 5 to 90 minutes, preferably 10 to 60 minutes, more preferably 15 to 45 minutes, and most preferably 20 to 30 minutes. It is believed that rapid cooling prevents the formation of boron clusters such as boron carbide and the loss of boron from the graphite lattice.

[0085] According to yet another embodiment, in the deagglomeration step, inter-particle contacts of the carbon particles in the graphitized granules are advantageously pulverized by shear forces. Preferably, in the deagglomeration step, the graphitized granules are deagglomerated using a mill, in particular a mill selected from a ball mill, a jet mill, a hammer mill, and a conical mill, preferably a jet mill. Deagglomeration of the granules results in particles with a particle size distribution range preferred for the following applications, in particular as an active material for the anode of a lithium-ion battery. The length of the grinding step and the choice of mill can be adjusted depending on the particle characteristics and application specifications. The aforementioned mills, in particular jet mills, are well suited for pulverizing inter-particle contacts of the carbon particles.

[0086] According to yet another embodiment, the boron source is selected from boron oxide, boric acid, elemental boron, and mixtures thereof, preferably boron oxide.

[0087] Advantageously, the boron source is added during the granulation step or the graphitization step, preferably during the graphitization step, in particular as a separate powder for mixing and evaporation. The choice of the boron source and boron introduction step may affect the resulting boron content in the particles and / or shell, in particular when comparing introduction of boron in the binder formulation versus introduction in a fluidized bed. Furthermore, the reaction time to achieve the desired boron distribution may also be affected.

[0088] According to yet another embodiment, the graphitization step is carried out in the presence of a nitrogen source, preferably nitrogen. Nitrogen gas can function not only as a process gas for fluidization and oxidation prevention, but also as a nitrogen source for doping. If nitrogen doping by a fluidization gas is not desired, argon can be used instead of nitrogen. In such a case, the nitrogen source can be added, for example, in the form of urea powder during the graphitization step.

[0089] Another aspect of the present disclosure relates to the use of the carbon particles described herein as an active material in the negative electrode of a battery, particularly a lithium-ion secondary battery. The anode can be fabricated from the active material or a mixture of active materials by coating a current collector with a mixture of the active material, binder, additive, and optionally a solvent.

[0090] Another aspect of the present disclosure relates to batteries, particularly lithium-ion secondary batteries, that include the carbon particles described herein, particularly as an active material in the negative electrode.

[0091] The battery may include a cathode assembled from the above-described negative electrode and containing an active material capable of reversibly intercalating and deintercalating lithium, such as lithium iron phosphate LiFePO4, lithium cobalt oxide LiCoO2, lithium nickel oxide LiNiO2, lithium manganese oxide LiMn2O4, and the so-called NCM materials LiNi x Mn y Co z O2(x+y+z=1), or LiNi 0.5 Mn 1.5 Examples of suitable electrolytes include, but are not limited to, related materials such as spinel structures like SiO4. Additionally, the battery may include a polymer or glass fiber separator and an electrolyte consisting of one or more organic solvents and a lithium salt, including, but not limited to, lithium hexafluorophosphate (LiPF6), lithium perchlorate (LiClO4), or lithium tetrafluoroborate (LiBF4). The electrolyte may also include additional additives, including, but not limited to, organic molecules such as vinylene carbonate or fluoroethylene carbonate, and / or salts such as lithium difluorophosphate. The use and combination of electrolytes and additives can be selected based on the properties of the anode and cathode active materials.

[0092] (Example) Various carbonaceous particles were granulated in a drum granulator using an aqueous starch solution as a binder, with the amount of starch being 7 wt % based on the total weight of the carbonaceous particles and starch binder.

[0093] The particle size distribution was determined by laser scattering Microtrac S3500 after dispersion with surfactant "Triton X100" using a Branson Sonifier 250-ultrasonic probe and ultrasonic treatment in a Branson 3510 ultrasonic bath.

[0094] The following carbon particles were used:

[0095] Carbonaceous particles 1: sponge coke I, d 10 :1.7μm, d 50 :8.7μm, d 90 :23.2μm, sulfur content 3.55% by weight Carbonaceous particles 2: sponge coke II, d 10 :2.5μm, d 50 :10.0μm, d 90 :21.8μm, Sulfur content: 0.85% by weight Carbonaceous particles 3: Needle coke I, d 10 :6.5μm;d 50 :19.0μm;d 90 :40.7μm, Sulfur content: 0.47% by weight Carbonaceous particles 4: needle coke II, d 10 :2.9μm;d 50 :9.1μm;d 90 :18.7μm, Sulfur content: 0.6% by weight

[0096] The resulting carbonaceous granules of sponge coke I+II were then heat treated in a rotary kiln at 300°C for a total residence time of 45 minutes, followed by heating to a temperature of 1100°C for a total residence time of 45 minutes in the rotary kiln. Needle coke I+II was treated in a separate batch oven at a peak temperature of 650°C for 12 hours, followed by heat treatment in a batch oven at a peak temperature of 1100°C for a total batch time of 12 hours.

[0097] The resulting carbonized granules were cooled to room temperature, after which 150 kg of the carbonized granules were introduced into an electrothermal fluidized bed (EFB) reactor, such as that described in U.S. Pat. No. 3,684,446. The EFB reactor was operated at a temperature of 2400°C to 2700°C and contained nitrogen as an inert gas. The carbonized granules remained in the EFB reactor for an average of approximately 60 minutes and were converted into graphitized granules. During the graphitization, 4.5 kg to 8.5 kg of dry boron oxide was added to the EFB reactor, depending on the intended boron doping. Upon exiting the EFB reactor, the graphitized granules were cooled to below 500°C over approximately 60 minutes. The cooled, graphitized granules were then introduced into a jet mill, where they were deagglomerated to produce the carbon particles.

[0098] The carbon particles had the following properties:

[0099] [Table 1]

[0100] The degree of graphitization is determined using the following formula:

[0101] Graphitization degree=(0.344nm-d 002 ) / (0.344nm-0.3354nm)

[0102] d 002 is the distance between two adjacent layers in graphite as measured by X-ray.

[0103] FIG. 1 shows the relationship between boron substitution and degree of graphitization.

[0104] Figure 2 shows XPS peaks for BC (186.5 eV) and BN (190.3 eV) bonds, as well as the absence of BB bonds, for a carbon particle sample made from natural flake graphite after treatment with boron oxide in an EFB furnace, treatment at a blackbody radiation temperature of 2300°C under a nitrogen atmosphere, and removal of boron nitride from the surface by peeling with tape. The dwell and cooling times and deagglomeration conditions for this flake graphite sample were similar to those described in Examples 1-6 above. The ratio of the 190.3 eV peak to the 186.5 eV peak is approximately 1.1. XPS measurements indicate that the carbon particles contain boron nitride. Furthermore, the absence of peaks for boron-boron bonds indicates the substantial absence of boron in the boron clusters.

[0105] 3 shows the volumetric particle size distribution of the deagglomerated carbon particles of a reference sample and a spherical natural flake graphite powder that was agglomerated and processed using the carbonization and EFB heat treatment process described above and then deagglomerated, thus illustrating the recovery of the particle size distribution during the deagglomeration step, which was performed in an air jet mill.

[0106] Table 2 shows the levels of metal impurities, oxygen, and sulfur in the deagglomerated samples.

[0107] [Table 2]

[0108] Furthermore, the carbon particles in all Examples contained less than 0.2 wt % of impurities such as the above-mentioned metals, oxygen, and sulfur, based on the total weight of the carbon particles.

[0109] Additionally, the carbon particles in all examples exhibited less than 0.05 wt. % boron carbide, based on the total weight of the carbon particles.

[0110] The carbon particles also contained at least 97% by weight carbon, based on the total weight of the carbon particles.

[0111] The amount of impurities (oxygen) was measured using a Leco ONH836 gas analyzer.

[0112] The amount of impurities (sulfur) was measured using a LECO SC-432 sulfur measuring device.

[0113] The amount of impurities (metallic, see above) was measured using a Jobin Yvon Horiba Ultima 2 ICP-OES.

[0114] The amount of boron nitride was determined by digesting the carbon particles with caustic (NaOH) in an Anton Paar Multiwave 7000 microwave digester. aq ) to 250°C and analyzing the residue from the caustic treatment using ICP-OES for boron.

[0115] The amount of boron was measured by the following procedure.

[0116] First, 3 g of sample was ashed in air in a muffle furnace at 780–800°C for 8 h. second, leaching boron oxide from the ash with 2% hot nitric acid, followed by filtering the boron nitride from the ash to obtain a nitric acid filtrate; Third, ICP-OES is used to determine the boron content in the nitric acid filtrate.

[0117] The amount of boron carbide was determined using the visual inspection method described above.

[0118] Below are initial results from electrochemical testing demonstrating the effectiveness of the particles described herein. The capacity and first cycle loss were obtained from powders prepared with an anode slurry containing the following: PVDF 9300 Kureha: 5-7%, carbon black: Super C65 Imerys: 2%, NMP: Alpha, graphite: 91-93%. The anodes were inserted into 2032 coin-type half-cells. The half-cells were tested in an Arbin 24-channel cycler in the following sequence: two cycles of C / 20, two cycles of C / 5, followed by a constant voltage at 5 mV until the current was less than 10% of the initial current. The capacity and first cycle loss represent the average of five cells.

[0119] [Table 3]

Claims

1. Carbon particles, at least 97 wt. % carbon, based on the total weight of the carbon particles; up to 0.2 wt. % impurities based on the total weight of the carbon particles; at least 0.08 wt. % boron based on the total weight of the carbon particles; and up to 0.05 wt. % boron carbide based on the total weight of the carbon particles carbon particles, including

2. The BET surface area of ​​the carbon particles is 0.5 to 50 m ２ / g, preferably 0.5 to 10 m ２ / g, more preferably 1 to 3 m ２ / g, more preferably 1 to 2 m ２ / g, and / or d of the carbon particles ００２ the spacing is between 0.3363 nm and 0.3355 nm, preferably between 0.3359 nm and 0.3355 nm; and / or d １１０ the spacing is 0.120 nm to 0.126 nm, preferably 0.1229 nm to 0.1236 nm, preferably 0.123027 nm to 0.123244 nm; The carbon particles according to claim 1 .

3. the XPS spectrum of the carbon particles has a first peak at 184.0 eV to 188.0 eV, preferably 185.0 eV to 187.5 eV, more preferably 185.5 eV to 187.0 eV, and most preferably at about 186.5 eV; and / or the XPS spectrum of the carbon particles has a second peak at 188.5 eV to 192.0 eV, preferably 189.0 eV to 191.5 eV, more preferably 189.5 eV to 191.0 eV, and most preferably at about 190.3 eV; and / or The XPS spectrum of the carbon particles has substantially no peak at about 187.7 eV; In particular, the intensity ratio of the first peak to the second peak in the XPS spectrum is 0.25 to 6.0, preferably 0.5 to 2, and more preferably 0.8 to 1.

25. Carbon particles according to claim 1 or 2.

4. the carbon particles comprise at least 97.5 wt.%, preferably at least 98 wt.%, more preferably at least 98.5 wt.%, carbon, based on the total weight of the particles; and / or % by weight, preferably at most 0.05%, more preferably at most 0.04%, even more preferably at most 0.03%, and most preferably at most 0.025%, based on the total weight of the carbon particles. Carbon particles according to any one of claims 1 to 3.

5. The impurities are at least one of metallic impurities such as transition metals, especially vanadium and / or iron, oxygen and sulfur, especially oxygen and sulfur, preferably at most 100 ppm oxygen and 100 ppm sulfur; Carbon particles according to any one of claims 1 to 4.

6. The carbon particles are and / or containing at least 0.1 wt. %, preferably at least 0.15 wt. %, more preferably at least 0.2 wt. %, even more preferably at least 0.3 wt. % boron, preferably in substitutional positions, based on the total weight of the carbon particles; and / or % boron, preferably in substitutional positions, based on the total weight of the carbon particles, Carbon particles according to any one of claims 1 to 5.

7. The carbon particles are containing nitrogen in an amount of at least 0.005 wt. %, preferably 0.01 to 0.05 wt. %, more preferably 0.015 to 0.04 wt. %, most preferably 0.02 to 0.03 wt. %, in particular based on the total weight of the carbon particles, preferably determined after removing boron nitride from the surface of the carbon particles, Carbon particles according to any one of claims 1 to 6.

8. the carbon particles comprise at most 0.03 wt. %, preferably at most 0.02 wt. %, more preferably at most 0.01 wt. %, and most preferably at most 0.005 wt. % boron carbide, based on the total weight of the carbon particles; and / or the carbon particles comprise up to 0.5 wt. % boron nitride, preferably up to 0.3 wt. % boron nitride, more preferably up to 0.1 wt. % boron nitride, based on the total weight of the carbon particles; Carbon particles according to any one of claims 1 to 7.

9. The carbon particles are Particle size distribution d ５０ is 3 to 30 μm, preferably 4 to 25 μm, more preferably 5 to 20 μm, and / or Particle size distribution d １０ is 1 to 25 μm, preferably 1.5 to 20 μm, more preferably 2 to 15 μm, and / or Particle size distribution d ９０ is 6 to 50 μm, preferably 8 to 45 μm, more preferably 10 to 35 μm; Carbon particles according to any one of claims 1 to 8.

10. the carbon particles are core-shell particles comprising a substantially non-graphitizable, particularly hard, carbon shell and an at least partially graphitized carbon core which may further comprise a graphitizable, particularly soft, carbon portion; Carbon particles according to any one of claims 1 to 9.

11. the core comprises 91% to 99% by weight, preferably 92% to 99% by weight, more preferably 94% to 98.5% by weight of the total weight of the carbon particles; the shell accounts for 1% to 9% by weight, preferably 1% to 8% by weight, more preferably 1.5% to 6% by weight of the total weight of the carbon particles; Carbon particles according to claim 10.

12. A method for producing carbon particles according to any one of claims 1 to 11, comprising the steps of: In the granulation step, the carbonaceous particles are granulated using a binder to produce carbonaceous granules; In a carbonization step, the carbonaceous granules are heated to a temperature of at least 1000°C to produce carbonized granules; In a graphitization step, the carbonized granules are introduced into an electric field to graphitize the carbonized granules, thereby producing graphitized granules; in a deagglomeration step, deagglomerating the graphitized granules, thereby producing the carbon particles; The method, wherein at least one of the granulating step, the carbonizing step, and the graphitizing step is carried out in the presence of a boron source.

13. The carbonaceous particles are Particle size distribution d ５０ is 3 to 30 μm, preferably 4 to 25 μm, more preferably 5 to 20 μm, and / or Particle size distribution d １０ is 1 to 25 μm, preferably 1.5 to 20 μm, more preferably 2 to 15 μm, and / or Particle size distribution d ９０ is 6 to 50 μm, preferably 8 to 45 μm, more preferably 10 to 35 μm, and / or the carbonaceous particles are selected from green petcoke particles, calcined petcoke particles, spherical flake graphite particles, spherical natural graphite particles, recycled anode powder particles, petroleum coke, pitch coke, carbonized wood, needle coke, sponge coke, metallurgical coke, coal tar-based carbon, mesocarbon, anthracite, synthetic graphite, natural graphite, expanded graphite, carbonized polymers, carbon black, and mixtures thereof, preferably selected from green petcoke particles, calcined petcoke particles, spherical flake graphite particles, spherical natural graphite particles, recycled anode powder particles, and mixtures thereof; The method of claim 12.

14. the binder comprises at least one of starch, modified starch, phenolic resin, modified kraft lignin, styrene butadiene rubber (SBR), and latex, and preferably comprises or consists of starch and / or modified starch; 14. The method of claim 12 or 13.

15. In the carbonization step, the carbonaceous granules are In the first heating step, the mixture is heated to a first temperature of 30°C to 700°C, preferably 30°C to 300°C, and then In the second heating step, the mixture is heated to a second temperature of 300°C to 1400°C, preferably 300°C to 1300°C, more preferably 300°C to 1100°C.

15. The method according to any one of claims 12 to 14.

16. The carbonaceous granules are and / or heated to said first temperature for 0.1 to 20 hours, preferably 0.25 to 12 hours; and / or heating at said second temperature for 0.1 to 20 hours, preferably 0.25 to 12 hours; 16. The method of claim 15.

17. The carbonized granules are introduced into an electrically heated fluidized bed reactor during the graphitization step; and / or the average residence time of the carbonized granules in the electric field during graphitization is 5 to 120 minutes, preferably 10 to 90 minutes, more preferably 15 to 60 minutes, and most preferably 20 to 45 minutes; and / or the graphitized granules are cooled after the graphitization step to a temperature of 500°C or less over a period of 5 to 90 minutes, preferably 10 to 60 minutes, more preferably 15 to 45 minutes, and most preferably 20 to 30 minutes; and / or In the deagglomeration step, the graphitized granules are deagglomerated using a mill, in particular a mill selected from a ball mill, a jet mill, a hammer mill, and a conical mill, preferably a jet mill.

17. The method of any one of claims 12 to 16.

18. the boron source is selected from boron oxide, boric acid, elemental boron, and mixtures thereof, preferably boron oxide; and / or the boron source is added in the granulation step or the graphitization step, preferably in the graphitization step, in particular as a separate powder for mixing and evaporation, and / or The graphitization step is carried out in the presence of a nitrogen source, preferably in the presence of nitrogen; 18. The method of any one of claims 12 to 17.

19. 12. Use of carbon particles according to any one of claims 1 to 11 as an active material in a negative electrode for a battery, in particular a lithium-ion secondary battery.

20. A battery, particularly a lithium ion secondary battery, comprising the carbon particles according to any one of claims 1 to 11, particularly as an active material of a negative electrode.

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